CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING DERMAL WIPE AND SURFACE WIPE SAMPLES FOR ANALYSIS OF POLAR ORGANIC POLLUTANTS (SOP-5.27)

EPA Science Inventory

The method for extracting and preparing a dermal or surface wipe sample for analysis of acidic persistent organic pollutants is summarized in this standard operating procedure. It covers the extraction and concentration of samples that are to be analyzed by gas chromatography/mas...

Evaluation of extraction methods for ochratoxin A detection in cocoa beans employing HPLC.

PubMed

Mishra, Rupesh K; Catanante, Gaëlle; Hayat, Akhtar; Marty, Jean-Louis

2016-01-01

Cocoa is an important ingredient for the chocolate industry and for many food products. However, it is prone to contamination by ochratoxin A (OTA), which is highly toxic and potentially carcinogenic to humans. In this work, four different extraction methods were tested and compared based on their recoveries. The best protocol was established which involves an organic solvent-free extraction method for the detection of OTA in cocoa beans using 1% sodium hydrogen carbonate (NaHCO3) in water within 30 min. The extraction method is rapid (as compared with existing methods), simple, reliable and practical to perform without complex experimental set-ups. The cocoa samples were freshly extracted and cleaned-up using immunoaffinity column (IAC) for HPLC analysis using a fluorescence detector. Under the optimised condition, the limit of detection (LOD) and limit of quantification (LOQ) for OTA were 0.62 and 1.25 ng ml(-1) respectively in standard solutions. The method could successfully quantify OTA in naturally contaminated samples. Moreover, good recoveries of OTA were obtained up to 86.5% in artificially spiked cocoa samples, with a maximum relative standard deviation (RSD) of 2.7%. The proposed extraction method could determine OTA at the level 1.5 µg kg(-)(1), which surpassed the standards set by the European Union for cocoa (2 µg kg(-1)). In addition, an efficiency comparison of IAC and molecular imprinted polymer (MIP) column was also performed and evaluated.

Development of a modified cortisol extraction procedure for intermediately sized fish not amenable to whole-body or plasma extraction methods.

PubMed

Guest, Taylor W; Blaylock, Reginald B; Evans, Andrew N

2016-02-01

The corticosteroid hormone cortisol is the central mediator of the teleost stress response. Therefore, the accurate quantification of cortisol in teleost fishes is a vital tool for addressing fundamental questions about an animal's physiological response to environmental stressors. Conventional steroid extraction methods using plasma or whole-body homogenates, however, are inefficient within an intermediate size range of fish that are too small for phlebotomy and too large for whole-body steroid extractions. To assess the potential effects of hatchery-induced stress on survival of fingerling hatchery-reared Spotted Seatrout (Cynoscion nebulosus), we developed a novel extraction procedure for measuring cortisol in intermediately sized fish (50-100 mm in length) that are not amenable to standard cortisol extraction methods. By excising a standardized portion of the caudal peduncle, this tissue extraction procedure allows for a small portion of a larger fish to be sampled for cortisol, while minimizing the potential interference from lipids that may be extracted using whole-body homogenization procedures. Assay precision was comparable to published plasma and whole-body extraction procedures, and cortisol quantification over a wide range of sample dilutions displayed parallelism versus assay standards. Intra-assay %CV was 8.54%, and average recovery of spiked samples was 102%. Also, tissue cortisol levels quantified using this method increase 30 min after handling stress and are significantly correlated with blood values. We conclude that this modified cortisol extraction procedure provides an excellent alternative to plasma and whole-body extraction procedures for intermediately sized fish, and will facilitate the efficient assessment of cortisol in a variety of situations ranging from basic laboratory research to industrial and field-based environmental health applications.

CTEPP STANDARD OPERATING PROCEDURE FOR DETECTION AND QUANTIFICATION OF TARGET ANALYTES BY GAS CHROMATOGRAPHY/MASS SPECTROMETRY (GC/MS) (SOP-5.24)

EPA Science Inventory

This standard operating procedure describes the method used for the determination of target analytes in sample extracts and related quality assurance/quality control sample extracts generated in the CTEPP study.

Systematic Assessment of Seven Solvent and Solid-Phase Extraction Methods for Metabolomics Analysis of Human Plasma by LC-MS

NASA Astrophysics Data System (ADS)

Sitnikov, Dmitri G.; Monnin, Cian S.; Vuckovic, Dajana

2016-12-01

The comparison of extraction methods for global metabolomics is usually executed in biofluids only and focuses on metabolite coverage and method repeatability. This limits our detailed understanding of extraction parameters such as recovery and matrix effects and prevents side-by-side comparison of different sample preparation strategies. To address this gap in knowledge, seven solvent-based and solid-phase extraction methods were systematically evaluated using standard analytes spiked into both buffer and human plasma. We compared recovery, coverage, repeatability, matrix effects, selectivity and orthogonality of all methods tested for non-lipid metabolome in combination with reversed-phased and mixed-mode liquid chromatography mass spectrometry analysis (LC-MS). Our results confirmed wide selectivity and excellent precision of solvent precipitations, but revealed their high susceptibility to matrix effects. The use of all seven methods showed high overlap and redundancy which resulted in metabolite coverage increases of 34-80% depending on LC-MS method employed as compared to the best single extraction protocol (methanol/ethanol precipitation) despite 7x increase in MS analysis time and sample consumption. The most orthogonal methods to methanol-based precipitation were ion-exchange solid-phase extraction and liquid-liquid extraction using methyl-tertbutyl ether. Our results help facilitate rational design and selection of sample preparation methods and internal standards for global metabolomics.

Systematic Assessment of Seven Solvent and Solid-Phase Extraction Methods for Metabolomics Analysis of Human Plasma by LC-MS

PubMed Central

Sitnikov, Dmitri G.; Monnin, Cian S.; Vuckovic, Dajana

2016-01-01

The comparison of extraction methods for global metabolomics is usually executed in biofluids only and focuses on metabolite coverage and method repeatability. This limits our detailed understanding of extraction parameters such as recovery and matrix effects and prevents side-by-side comparison of different sample preparation strategies. To address this gap in knowledge, seven solvent-based and solid-phase extraction methods were systematically evaluated using standard analytes spiked into both buffer and human plasma. We compared recovery, coverage, repeatability, matrix effects, selectivity and orthogonality of all methods tested for non-lipid metabolome in combination with reversed-phased and mixed-mode liquid chromatography mass spectrometry analysis (LC-MS). Our results confirmed wide selectivity and excellent precision of solvent precipitations, but revealed their high susceptibility to matrix effects. The use of all seven methods showed high overlap and redundancy which resulted in metabolite coverage increases of 34–80% depending on LC-MS method employed as compared to the best single extraction protocol (methanol/ethanol precipitation) despite 7x increase in MS analysis time and sample consumption. The most orthogonal methods to methanol-based precipitation were ion-exchange solid-phase extraction and liquid-liquid extraction using methyl-tertbutyl ether. Our results help facilitate rational design and selection of sample preparation methods and internal standards for global metabolomics. PMID:28000704

New method for determination of ten pesticides in human blood.

PubMed

García-Repetto, R; Giménez, M P; Repetto, M

2001-01-01

An analytical method was developed for precise identification and quantitation of 10 pesticides in human blood. The pesticides studied, which have appeared frequently in actual cases, were endosulfan, lindane, parathion, ethyl-azinphos, diazinon, malathion, alachlor, tetradifon, fenthion and dicofol (o-p' and p-p' isomers). The current method replaces an earlier method which involved liquid-liquid extraction with a mixture of n-hexane-benzene (1 + 1). The extraction is performed by solid-phase extraction, with C18 cartridges and 2 internal standards, perthane and triphenylphosphate. Eluates were analyzed by gas chromatography (GC) with nitrogen-phosphorus and electrochemical detectors. Results were confirmed by GC-mass spectrometry in the electron impact mode. Blood blank samples spiked with 2 standard mixtures and an internal standard were used for quantitation. Mean recoveries ranged from 71.83 to 97.10%. Detection and quantitation limits are reported for each pesticide. Examples are provided to show the application of the present method to actual samples.

Net analyte signal standard addition method for simultaneous determination of sulphadiazine and trimethoprim in bovine milk and veterinary medicines.

PubMed

Hajian, Reza; Mousavi, Esmat; Shams, Nafiseh

2013-06-01

Net analyte signal standard addition method has been used for the simultaneous determination of sulphadiazine and trimethoprim by spectrophotometry in some bovine milk and veterinary medicines. The method combines the advantages of standard addition method with the net analyte signal concept which enables the extraction of information concerning a certain analyte from spectra of multi-component mixtures. This method has some advantages such as the use of a full spectrum realisation, therefore it does not require calibration and prediction step and only a few measurements require for the determination. Cloud point extraction based on the phenomenon of solubilisation used for extraction of sulphadiazine and trimethoprim in bovine milk. It is based on the induction of micellar organised media by using Triton X-100 as an extraction solvent. At the optimum conditions, the norm of NAS vectors increased linearly with concentrations in the range of 1.0-150.0 μmolL(-1) for both sulphadiazine and trimethoprim. The limits of detection (LOD) for sulphadiazine and trimethoprim were 0.86 and 0.92 μmolL(-1), respectively. Copyright © 2012 Elsevier Ltd. All rights reserved.

[Extraction method suitable for detection of unheated crustaceans including cephalothorax by ELISA].

PubMed

Shibahara, Yusuke; Yamada, Itta; Uesaka, Yoshihiko; Uneo, Noriko; Abe, Akihisa; Ohashi, Eiji; Shiomi, Kazuo

2009-08-01

When unheated whole samples of crustaceans (shrimp, prawn and crab) were analyzed with our ELISA kit (FA test EIA-Crustacean 'Nissui') using anti-tropomyosin antibodies, a remarkable reduction in reactivity was recognized. This reduction in activity was found to be due to the digestion of tropomyosin during the extraction process by proteases contained in cephalothorax. To avoid the digestion of tropomyosin by proteases, we developed an extraction method (heating method) suitable for the detection of tropomyosin in unheated crustaceans including cephalothorax. Experiments with unheated whole samples of various species of crustaceans confirmed that the heating method greatly improved the low reactivity in the standard method; the heating method gave extraction efficiencies of as high as 93-107%. Various processed crustaceans with cephalothorax, such as dry products (unheated or weakly heated products) and pickles in soy sauce (unheated products), that showed low reactivity with the standard method were confirmed to give superior results with the heating method. These results indicated that the developed heating method is suitable for detecting unheated crustaceans with cephalothorax by means of the ELISA kit.

Qualitative and quantitative evaluation of the genomic DNA extracted from GMO and non-GMO foodstuffs with four different extraction methods.

PubMed

Peano, Clelia; Samson, Maria Cristina; Palmieri, Luisa; Gulli, Mariolina; Marmiroli, Nelson

2004-11-17

The presence of DNA in foodstuffs derived from or containing genetically modified organisms (GMO) is the basic requirement for labeling of GMO foods in Council Directive 2001/18/CE (Off. J. Eur. Communities 2001, L1 06/2). In this work, four different methods for DNA extraction were evaluated and compared. To rank the different methods, the quality and quantity of DNA extracted from standards, containing known percentages of GMO material and from different food products, were considered. The food products analyzed derived from both soybean and maize and were chosen on the basis of the mechanical, technological, and chemical treatment they had been subjected to during processing. Degree of DNA degradation at various stages of food production was evaluated through the amplification of different DNA fragments belonging to the endogenous genes of both maize and soybean. Genomic DNA was extracted from Roundup Ready soybean and maize MON810 standard flours, according to four different methods, and quantified by real-time Polymerase Chain Reaction (PCR), with the aim of determining the influence of the extraction methods on the DNA quantification through real-time PCR.

Antioxidant components of Viburnum opulus L. determined by on-line HPLC-UV-ABTS radical scavenging and LC-UV-ESI-MS methods.

PubMed

Karaçelik, Ayça Aktaş; Küçük, Murat; İskefiyeli, Zeynep; Aydemir, Sezgin; De Smet, Seppe; Miserez, Bram; Sandra, Patrick

2015-05-15

Antioxidant activity of the juice and seed and skin extracts prepared with methanol, acetonitrile, and water of Viburnum opulus L. grown in Eastern Black Sea Region were studied with an on-line HPLC-ABTS method and off-line antioxidant methods, among which a linear positive correlation was observed. The fruit extracts were analysed with the HPLC-UV method optimised with 14 standard phenolics. Identification of the phenolic components in the juice was made using an HPLC-UV-ESI-MS method. Nineteen phenolic compounds in juice were identified by comparing the retention times and mass spectra with those of the standards and the phenolics reported in the literature. The major peaks in the juice belonged to coumaroyl-quinic acid, chlorogenic acid, procyanidin B2, and procyanidin trimer. Quite different antioxidant composition profiles were obtained from the extracts with the solvents of different polarities. The antioxidant activities of the seed extracts were higher than those of the skin extracts in general. Copyright © 2014 Elsevier Ltd. All rights reserved.

Use of Membrane Filtration as an Alternative Method in the Extraction of Microcystins Produced by Harmful Algal Blooms

EPA Science Inventory

Current methods invariably require sample concentration, typically solid-phase extraction, so as to be amendable for measurement at ambient concentration levels. Such methods (i.e. EPA Method 544) are only validated for a limited number of the known variants where standards are ...

Rapid extraction and assay of uranium from environmental surface samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barrett, Christopher A.; Chouyyok, Wilaiwan; Speakman, Robert J.

Extraction methods enabling faster removal and concentration of uranium compounds for improved trace and low-level assay are demonstrated for standard surface sampling material in support of nuclear safeguards efforts, health monitoring, and other nuclear analysis applications. A key problem with the existing surface sampling swipes is the requirement for complete digestion of sample and sampling matrix. This is a time-consuming and labour-intensive process that limits laboratory throughput, elevates costs, and increases background levels. Various extraction methods are explored for their potential to quickly and efficiently remove different chemical forms of uranium from standard surface sampling material. A combination of carbonatemore » and peroxide solutions is shown to give the most rapid and complete form of uranyl compound extraction and dissolution. This rapid extraction process is demonstrated to be compatible with standard inductive coupled plasma mass spectrometry methods for uranium isotopic assay as well as screening techniques such as x-ray fluorescence. The general approach described has application beyond uranium to other analytes of nuclear forensic interest (e.g., rare earth elements and plutonium) as well as heavy metals for environmental and industrial hygiene monitoring.« less

DNA extraction methods for detecting genetically modified foods: A comparative study.

PubMed

Elsanhoty, Rafaat M; Ramadan, Mohamed Fawzy; Jany, Klaus Dieter

2011-06-15

The work presented in this manuscript was achieved to compare six different methods for extracting DNA from raw maize and its derived products. The methods that gave higher yield and quality of DNA were chosen to detect the genetic modification in the samples collected from the Egyptian market. The different methods used were evaluated for extracting DNA from maize kernels (without treatment), maize flour (mechanical treatment), canned maize (sweet corn), frozen maize (sweet corn), maize starch, extruded maize, popcorn, corn flacks, maize snacks, and bread made from corn flour (mechanical and thermal treatments). The quality and quantity of the DNA extracted from the standards, containing known percentages of GMO material and from the different food products were evaluated. For qualitative detection of the GMO varieties in foods, the GMOScreen 35S/NOS test kit was used, to screen the genetic modification in the samples. The positive samples for the 35S promoter and/or the NOS terminator were identified by the standard methods adopted by EU. All of the used methods extracted yielded good DNA quality. However, we noted that the purest DNA extract were obtained using the DNA extraction kit (Roche) and this generally was the best method for extracting DNA from most of the maize-derived foods. We have noted that the yield of DNA extracted from maize-derived foods was generally lower in the processed products. The results indicated that 17 samples were positive for the presence of 35S promoter, while 34% from the samples were positive for the genetically modified maize line Bt-176. Copyright © 2010 Elsevier Ltd. All rights reserved.

Analgesic, antibacterial and central nervous system depressant activities of Albizia procera leaves.

PubMed

Khatoon, Mst Mahfuza; Khatun, Mst Hajera; Islam, Md Ekramul; Parvin, Mst Shahnaj

2014-04-01

To ascertain analgesic, antibacterial and central nervous system (CNS) depressant activities of ethyl acetate, dichloromethane and carbon tetrachloride fractions of methanol extract of Albizia procera (A. procera) leaves. Leaves extracts of A. procera were tested for analgesic activity by acetic acid induced and formalin test method in mice. The in vitro antibacterial activity was performed by agar well diffusion method. CNS depressant activity was evaluated by hole cross and open field tests. All the extracts at 200 mg/kg exhibited significant (P<0.01) analgesic activity in acetic acid induced and formalin tests method in mice. Analgesic activity of the ethyl acetate fraction was almost same like as standard drug indomethacin in acetic acid induced method. The CNS depressant activity of the extracts at 500 mg/kg was comparable to the positive control diazepam as determined by hole cross and open field test method. The extracts exhibited moderate antimicrobial activity against all the tested microorganisms (Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa, Esherichia coli, Shigella soneii, Shigella boydii) at concentration of 0.8 mg/disc. The measured diameter of zone of inhibition for the extracts was within the range of 7 to 12 mm which was less than the standard kanamycin (16-24 mm). It is concluded that all the extracts possess potential analgesic and CNS depressants activity. This study also showed that different fractions of methanol extract could be potential sources of new antimicrobial agents.

Evaluation of a Wipe Surface Sample Method for Collection of Bacillus Spores from Nonporous Surfaces▿

PubMed Central

Brown, Gary S.; Betty, Rita G.; Brockmann, John E.; Lucero, Daniel A.; Souza, Caroline A.; Walsh, Kathryn S.; Boucher, Raymond M.; Tezak, Mathew; Wilson, Mollye C.; Rudolph, Todd

2007-01-01

Polyester-rayon blend wipes were evaluated for efficiency of extraction and recovery of powdered Bacillus atrophaeus spores from stainless steel and painted wallboard surfaces. Method limits of detection were also estimated for both surfaces. The observed mean efficiency of polyester-rayon blend wipe recovery from stainless steel was 0.35 with a standard deviation of ±0.12, and for painted wallboard it was 0.29 with a standard deviation of ±0.15. Evaluation of a sonication extraction method for the polyester-rayon blend wipes produced a mean extraction efficiency of 0.93 with a standard deviation of ±0.09. Wipe recovery quantitative limits of detection were estimated at 90 CFU per unit of stainless steel sample area and 105 CFU per unit of painted wallboard sample area. The method recovery efficiency and limits of detection established in this work provide useful guidance for the planning of incident response environmental sampling following the release of a biological agent such as Bacillus anthracis. PMID:17122390

Evaluation of a wipe surface sample method for collection of Bacillus spores from nonporous surfaces.

PubMed

Brown, Gary S; Betty, Rita G; Brockmann, John E; Lucero, Daniel A; Souza, Caroline A; Walsh, Kathryn S; Boucher, Raymond M; Tezak, Mathew; Wilson, Mollye C; Rudolph, Todd

2007-02-01

Polyester-rayon blend wipes were evaluated for efficiency of extraction and recovery of powdered Bacillus atrophaeus spores from stainless steel and painted wallboard surfaces. Method limits of detection were also estimated for both surfaces. The observed mean efficiency of polyester-rayon blend wipe recovery from stainless steel was 0.35 with a standard deviation of +/-0.12, and for painted wallboard it was 0.29 with a standard deviation of +/-0.15. Evaluation of a sonication extraction method for the polyester-rayon blend wipes produced a mean extraction efficiency of 0.93 with a standard deviation of +/-0.09. Wipe recovery quantitative limits of detection were estimated at 90 CFU per unit of stainless steel sample area and 105 CFU per unit of painted wallboard sample area. The method recovery efficiency and limits of detection established in this work provide useful guidance for the planning of incident response environmental sampling following the release of a biological agent such as Bacillus anthracis.

Analgesic, antibacterial and central nervous system depressant activities of Albizia procera leaves

PubMed Central

Khatoon, Mst. Mahfuza; Khatun, Mst. Hajera; Islam, Md. Ekramul; Parvin, Mst. Shahnaj

2014-01-01

Objective To ascertain analgesic, antibacterial and central nervous system (CNS) depressant activities of ethyl acetate, dichloromethane and carbon tetrachloride fractions of methanol extract of Albizia procera (A. procera) leaves. Methods Leaves extracts of A. procera were tested for analgesic activity by acetic acid induced and formalin test method in mice. The in vitro antibacterial activity was performed by agar well diffusion method. CNS depressant activity was evaluated by hole cross and open field tests. Results All the extracts at 200 mg/kg exhibited significant (P<0.01) analgesic activity in acetic acid induced and formalin tests method in mice. Analgesic activity of the ethyl acetate fraction was almost same like as standard drug indomethacin in acetic acid induced method. The CNS depressant activity of the extracts at 500 mg/kg was comparable to the positive control diazepam as determined by hole cross and open field test method. The extracts exhibited moderate antimicrobial activity against all the tested microorganisms (Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa, Esherichia coli, Shigella soneii, Shigella boydii) at concentration of 0.8 mg/disc. The measured diameter of zone of inhibition for the extracts was within the range of 7 to 12 mm which was less than the standard kanamycin (16-24 mm). Conclusions It is concluded that all the extracts possess potential analgesic and CNS depressants activity. This study also showed that different fractions of methanol extract could be potential sources of new antimicrobial agents. PMID:25182551

A novel reverse phase high-performance liquid chromatography method for standardization of Orthosiphon stamineus leaf extracts

PubMed Central

Saidan, Noor Hafizoh; Aisha, Abdalrahim F.A.; Hamil, Mohd Shahrul Ridzuan; Majid, Amin Malik Shah Abdul; Ismail, Zhari

2015-01-01

Background: Orthosiphon stamineus Benth. (Lamiaceae) is a traditional medicinal plant which has been used in treating various ailments such as kidney diseases, bladder inflammation, arthritis and diabetes. The leaves contain high concentration of phenolic compounds, thus, rosmarinic acid (RA), 3’-hydroxy-5, 6, 7, 4’-tetramethoxyflavone (TMF), sinensetin (SIN) and eupatorin (EUP) were chosen as a marker compounds for standardization of various O. stamineus leaf extracts. Objective: The aim was to develop and validate a new high-performance liquid chromatography (HPLC) method for quantification of 4 marker compounds (RA, TMF, SIN, EUP) in various O. stamineus leaf extracts. Materials and Methods: The method was developed and validated using RP-HPLC-diode-array detection at 320 nm for accuracy, precision and limits of detection and was applied for quantification of it markers in five different extracts prepared in solvents with increasing polarity, using a gradient mobile phase 0.1% formic acid: Acetonitrile at a flow rate of 1 ml/min on reverse phase acclaim polar advantage II C18 column (3 μm, 3 × 150 mm) with 18 min separation time. Results: The developed method provided satisfactory precision, and the accuracy of this method was in the range of 90.2% to 105.5%. All of 4 compounds showed good linearity at R2 > 0.999. Conclusion: The developed method is a simple, cost effective with shorter run time (18 min) in comparison to previous methods (30 min) and utilization of environmental-friendly solvents system. Therefore, this method has the potential to replace currently used methods in the routine standardization work of O. stamineus extracts, raw materials and its commercial products. PMID:25598631

Extraction of organic contaminants from marine sediments and tissues using microwave energy.

PubMed

Jayaraman, S; Pruell, R J; McKinney, R

2001-07-01

In this study, we compared microwave solvent extraction (MSE) to conventional methods for extracting organic contaminants from marine sediments and tissues with high and varying moisture content. The organic contaminants measured were polychlorinated biphenyl (PCB) congeners, chlorinated pesticides, and polycyclic aromatic hydrocarbons (PAHs). Initial experiments were conducted on dry standard reference materials (SRMs) and field collected marine sediments. Moisture content in samples greatly influenced the recovery of the analytes of interest. When wet sediments were included in a sample batch, low recoveries were often encountered in other samples in the batch, including the dry SRM. Experiments were conducted to test the effect of standardizing the moisture content in all samples in a batch prior to extraction. SRM1941a (marine sediment). SRM1974a (mussel tissue), as well as QA96SED6 (marine sediment), and QA96TIS7 (marine tissue), both from 1996 NIST Intercalibration Exercise were extracted using microwave and conventional methods. Moisture levels were adjusted in SRMs to match those of marine sediment and tissue samples before microwave extraction. The results demonstrated that it is crucial to standardize the moisture content in all samples, including dry reference material to ensure good recovery of organic contaminants. MSE yielded equivalent or superior recoveries compared to conventional methods for the majority of the compounds evaluated. The advantages of MSE over conventional methods are reduced solvent usage, higher sample throughput and the elimination of halogenated solvent usage.

Preparation of Orthosiphon stamineus enriched-extracts and evaluation of their free radical scavenging activity

NASA Astrophysics Data System (ADS)

Mansor, Che Nurul Ain Nadirah Che; Latip, Jalifah; Markom, Masturah

2016-11-01

Orthosiphon stamineus is one of the important herbal plants used in folk medicine to cure variety of diseases. Three compounds namely rosmarinic acid (RA), sinensetin (SEN) and eupatorin (EUP) were identified as the bioactive markers. However, a standardized extraction method for the preparation of O. stamineus extract enriched with the bioactive compounds was still undiscovered. Thus, this study aims to establish the optimal extraction method that can be used to prepare the enriched extract with anti-oxidant property. Maceration, reflux and Soxhlet were the extraction methods employed, with ethanol, 50% (v/v) aqueous ethanol and water were chosen as the solvents. Each extracts were evaluated for their biomarker contents (RA, SEN and EUP) and anti-oxidant capacity using thin layer chromatography (TLC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay respectively. Among the three extraction methods employed, the highest total extraction yield was obtained from reflux (72.73%) followed by Soxhlet (62.51%) and maceration (37.78%). Although all extracts found to contain the three biomarkers via TLC visualization analysis, there was variation in the extracts' anti-oxidant capacity, ranging from 6.17% to 72.97%. The variation was expected to be due to the difference in the quantity of the biomarkers in each extract. Furthermore, the anti-oxidative potency of the RA was found comparable to natural anti-oxidant vitamin C, and higher than the synthetic anti-oxidant butylated hydroxyl toluene (BHT). These preliminary results may serve as a starting point towards the preparation of standardized bioactive O. stamineus extract.

Improvement in botanical standardization of commercial freeze-dried herbal extracts by using the combination of antioxidant capacity and constituent marker concentrations.

PubMed

Ninfali, Paolino; Gennari, Lorenzo; Biagiotti, Enrica; Cangi, Francesca; Mattoli, Luisa; Maidecchi, Anna

2009-01-01

Botanical extracts are standardized to > or = 1 marker compounds (MCs). This standardization provides a certain level of quality control, but not complete quality assurance. Thus, industries are looking for other satisfactory systems to improve standardization. This study focuses on the standardization of herbal medicines by combining 2 parameters: the concentration of the MC and antioxidant capacity. Antioxidant capacity was determined with the oxygen radical absorbance capacity (ORAC) method and the concentrations of the MCs, by high-performance liquid chromatography. Total phenols were also determined by the Folin-Ciocolteau method. The ORAC values, expressed as micromol Trolox equivalents/100 g (ORAC %), of 12 commercial herbal extracts were related to the ORAC values of the respective pure MCs at the concentrations at which the MCs occur in products (ORAC-MC %). The ORAC % values of 11 extracts were higher than those of the respective MCs and the ratios ORAC-MC %/ORAC % ranged from 0.007 to 0.7, whereas in the case of Olea europaea leaves, the same ratio was 1.36. The ORAC parameters and their ratios, as well as the linear relationship between ORAC-MC % and ORAC %, are described and discussed as tools for improving the standardization of herbal products and detecting modifications due to herb processing and storage.

A novel reverse phase high-performance liquid chromatography method for standardization of Orthosiphon stamineus leaf extracts.

PubMed

Saidan, Noor Hafizoh; Aisha, Abdalrahim F A; Hamil, Mohd Shahrul Ridzuan; Majid, Amin Malik Shah Abdul; Ismail, Zhari

2015-01-01

Orthosiphon stamineus Benth. (Lamiaceae) is a traditional medicinal plant which has been used in treating various ailments such as kidney diseases, bladder inflammation, arthritis and diabetes. The leaves contain high concentration of phenolic compounds, thus, rosmarinic acid (RA), 3'-hydroxy-5, 6, 7, 4'-tetramethoxyflavone (TMF), sinensetin (SIN) and eupatorin (EUP) were chosen as a marker compounds for standardization of various O. stamineus leaf extracts. The aim was to develop and validate a new high-performance liquid chromatography (HPLC) method for quantification of 4 marker compounds (RA, TMF, SIN, EUP) in various O. stamineus leaf extracts. The method was developed and validated using RP-HPLC-diode-array detection at 320 nm for accuracy, precision and limits of detection and was applied for quantification of it markers in five different extracts prepared in solvents with increasing polarity, using a gradient mobile phase 0.1% formic acid: Acetonitrile at a flow rate of 1 ml/min on reverse phase acclaim polar advantage II C18 column (3 μm, 3 × 150 mm) with 18 min separation time. The developed method provided satisfactory precision, and the accuracy of this method was in the range of 90.2% to 105.5%. All of 4 compounds showed good linearity at R2 > 0.999. The developed method is a simple, cost effective with shorter run time (18 min) in comparison to previous methods (30 min) and utilization of environmental-friendly solvents system. Therefore, this method has the potential to replace currently used methods in the routine standardization work of O. stamineus extracts, raw materials and its commercial products.

Modified procedure to determine acid-insoluble lignin in wood and pulp

DOE Office of Scientific and Technical Information (OSTI.GOV)

Effland, M.J.

1977-10-01

If wood is treated with strong acid, carbohydrates are hydrolyzed and solubilized. The insoluble residue is by definition lignin and can be measured gravimetrically. The standard method of analysis requires samples of 1 or 2 g of wood or pulp. In research at this laboratory these amounts of sample are often not available for analytical determinations. Thus we developed a modification of the standard procedure suitable for much smaller sample amounts. The modification is based on the procedure of Saeman. Wood samples require extraction prior to lignin analysis to remove acid-insoluble extractives that will be measured as lignin. Usually thismore » involves only a standard extraction with ethanol--benzene. However, woods high in tannin must also be subjected to extraction with alcohol. Pulps seldom require extraction.« less

Phytopharmacological evaluation of ethanol extract of Sida cordifolia L. roots

PubMed Central

Momin, Mohammad Abdul Motalib; Bellah, Sm Faysal; Rahman, Sarder Mohammad Raussel; Rahman, Ahmed Ayedur; Murshid, Gazi Mohammad Monjur; Emran, Talha Bin

2014-01-01

Objective To investigate the phytochemical screening (group determination) and selected pharmacological activities (antioxidant, antimicrobial and analgesic activity) of the plant Sida cordifolia Linn (S. cordifolia). Methods Eighty percent concentrated ethanol extract of the roots was used. To identify the chemical constituents of plant extract standard procedures were followed. In phytochemical screening the crude extract was tested for the presence of different chemical groups like reducing sugar, tannins, saponins, steroids, flavonoids, gums, alkaloids and glycosides. The antioxidant property of ethanolic extract of S. cordifolia was assessed by DPPH free radical scavenging activity. Analgesic activity of the extract was tested using the model of acetic acid induced writhing in mice. Diclofenac sodium is used as reference standard drug for the analgesic activity test. Antibacterial activity of plant extract was carried out using disc diffusion method with five pathogenic bacteria comparison with kanamycin as a standard. Results Phytochemical analysis of the ethanolic extract of the roots of S. cordifolia indicated the presence of reducing sugar, alkaloids, steroids and saponins. In DPPH scavenging assay the IC50 value was found to be 50 µg/mL which was not comparable to the standard ascorbic acid. The crude extract produced 44.30% inhibition of writhing at the dose of 500 mg/kg body weight which is statistically significant (P>0.001). The in vitro antimicrobial activity of the ethanol extract of the roots of S. cordifolia showed no antimicrobial activity against five types of microorganisms. The experiment was conducted only with five species of bacteria as test species, which do not at all indicate the total inactivity against micro-organisms. Conclusions The obtained results provide a support for the use of this plant in traditional medicine but further pharmacological studies are required. PMID:24144125

Monitoring of multiple bacteriocins through a developed dual extraction protocol and comparison of HPLC-DAD with turbidometry as their quantification system.

PubMed

Katharopoulos, Efstathios; Touloupi, Katerina; Touraki, Maria

2016-08-01

The present study describes the development of a simple and efficient screening system that allows identification and quantification of nine bacteriocins produced by Lactococcus lactis. Cell-free L. lactis extracts presented a broad spectrum of antibacterial activity, including Gram-negative bacteria, Gram-positive bacteria, and fungi. The characterization of their sensitivity to pH, and heat, showed that the extracts retained their antibacterial activity at extreme pH values and in a wide temperature range. The loss of antibacterial activity following treatment of the extracts with lipase or protease suggests a lipoproteinaceous nature of the produced antimicrobials. The extracts were subjected to a purification protocol that employs a two phase extraction using ammonium sulfate precipitation and organic solvent precipitation, followed by ion exchange chromatography, solid phase extraction and HPLC. In the nine fractions that presented antimicrobial activity, bacteriocins were quantified by the turbidometric method using a standard curve of nisin and by the HPLC method with nisin as the external standard, with both methods producing comparable results. Turbidometry appears to be unique in the qualitative determination of bacteriocins but the only method suitable to both separate and quantify the bacteriocins providing increased sensitivity, accuracy, and precision is HPLC. Copyright © 2016 Elsevier B.V. All rights reserved.

Comparison of Chemical Extraction Methods for Determination of Soil Potassium in Different Soil Types

NASA Astrophysics Data System (ADS)

Zebec, V.; Rastija, D.; Lončarić, Z.; Bensa, A.; Popović, B.; Ivezić, V.

2017-12-01

Determining potassium supply of soil plays an important role in intensive crop production, since it is the basis for balancing nutrients and issuing fertilizer recommendations for achieving high and stable yields within economic feasibility. The aim of this study was to compare the different extraction methods of soil potassium from arable horizon of different types of soils with ammonium lactate method (KAL), which is frequently used as analytical method for determining the accessibility of nutrients and it is a common method used for issuing fertilizer recommendations in many Europe countries. In addition to the ammonium lactate method (KAL, pH 3.75), potassium was extracted with ammonium acetate (KAA, pH 7), ammonium acetate ethylenediaminetetraacetic acid (KAAEDTA, pH 4.6), Bray (KBRAY, pH 2.6) and with barium chloride (K_{BaCl_2 }, pH 8.1). The analyzed soils were extremely heterogeneous with a wide range of determined values. Soil pH reaction ( {pH_{H_2 O} } ) ranged from 4.77 to 8.75, organic matter content ranged from 1.87 to 4.94% and clay content from 8.03 to 37.07%. In relation to KAL method as the standard method, K_{BaCl_2 } method extracts 12.9% more on average of soil potassium, while in relation to standard method, on average KAA extracts 5.3%, KAAEDTA 10.3%, and KBRAY 27.5% less of potassium. Comparison of analyzed extraction methods of potassium from the soil is of high precision, and most reliable comparison was KAL method with KAAEDTA, followed by a: KAA, K_{BaCl_2 } and KBRAY method. Extremely significant statistical correlation between different extractive methods for determining potassium in the soil indicates that any of the methods can be used to accurately predict the concentration of potassium in the soil, and that carried out research can be used to create prediction model for concentration of potassium based on different methods of extraction.

Application of FT-IR Classification Method in Silica-Plant Extracts Composites Quality Testing

NASA Astrophysics Data System (ADS)

Bicu, A.; Drumea, V.; Mihaiescu, D. E.; Purcareanu, B.; Florea, M. A.; Trică, B.; Vasilievici, G.; Draga, S.; Buse, E.; Olariu, L.

2018-06-01

Our present work is concerned with the validation and quality testing efforts of mesoporous silica - plant extracts composites, in order to sustain the standardization process of plant-based pharmaceutical products. The synthesis of the silica support were performed by using a TEOS based synthetic route and CTAB as a template, at room temperature and normal pressure. The silica support was analyzed by advanced characterization methods (SEM, TEM, BET, DLS and FT-IR), and loaded with Calendula officinalis and Salvia officinalis standardized extracts. Further desorption studies were performed in order to prove the sustained release properties of the final materials. Intermediate and final product identification was performed by a FT-IR classification method, using the MID-range of the IR spectra, and statistical representative samples from repetitive synthetic stages. The obtained results recommend this analytical method as a fast and cost effective alternative to the classic identification methods.

Development and validation of an improved method for the determination of chloropropanols in paperboard food packaging by GC-MS.

PubMed

Mezouari, S; Liu, W Yun; Pace, G; Hartman, T G

2015-01-01

The objective of this study was to develop an improved analytical method for the determination of 3-chloro-1,2-propanediol (3-MCPD) and 1,3-dichloropropanol (1,3-DCP) in paper-type food packaging. The established method includes aqueous extraction, matrix spiking of a deuterated surrogate internal standard (3-MCPD-d₅), clean-up using Extrelut solid-phase extraction, derivatisation using a silylation reagent, and GC-MS analysis of the chloropropanols as their corresponding trimethyl silyl ethers. The new method is applicable to food-grade packaging samples using European Commission standard aqueous extraction and aqueous food stimulant migration tests. In this improved method, the derivatisation procedure was optimised; the cost and time of the analysis were reduced by using 10 times less sample, solvents and reagents than in previously described methods. Overall the validation data demonstrate that the method is precise and reliable. The limit of detection (LOD) of the aqueous extract was 0.010 mg kg(-1) (w/w) for both 3-MCPD and 1,3-DCP. Analytical precision had a relative standard deviation (RSD) of 3.36% for 3-MCPD and an RSD of 7.65% for 1,3-DCP. The new method was satisfactorily applied to the analysis of over 100 commercial paperboard packaging samples. The data are being used to guide the product development of a next generation of wet-strength resins with reduced chloropropanol content, and also for risk assessments to calculate the virtual safe dose (VSD).

Screening of Bauhinia purpurea Linn. for analgesic and anti-inflammatory activities

PubMed Central

Shreedhara, C.S.; Vaidya, V.P.; Vagdevi, H.M.; Latha, K.P.; Muralikrishna, K.S.; Krupanidhi, A.M.

2009-01-01

Objectives: Ethanol extract of the stem of Bauhinia purpurea Linn. was subjected to analgesic and anti-inflammatory activities in animal models. Materials and Methods: Albino Wistar rats and mice were the experimental animals respectively. Different CNS depressant paradigms like analgesic activity (determined by Eddy's hot plate method and acetic acid writhing method) and anti-inflammatory activity determined by carrageenan induced paw edema using plethysmometer in albino rats) were carried out, following the intra-peritoneal administration of ethanol extract of Bauhinia purpurea Linn. (BP) at the dose level of 50 mg/kg and 100 mg/kg. Results: The analgesic and anti-inflammatory activities of ethanol extracts of BP were significant (P < 0.001). The maximum analgesic effect was observed at 120 min at the dose of 100 mg/kg (i.p.) and was comparable to that of standard analgin (150 mg/kg) and the percentage of edema inhibition effect was 46.4% and 77% for 50 mg/kg and 100 mg/kg (i.p) respectively. Anti-inflammatory activity was compared with standard Diclofenac sodium (5 mg/kg). Conclusion: Ethanol extract of Bauhinia purpurea has shown significant analgesic and anti-inflammatory activities at the dose of 100 mg/kg and was comparable with corresponding standard drugs. The activity was attributed to the presence of phytoconstituents in the tested extract. PMID:20336222

Quantification of almond skin polyphenols by liquid chromatography-mass spectrometry.

PubMed

Bolling, Bradley W; Dolnikowski, Gregory; Blumberg, Jeffrey B; Oliver Chen, C Y

2009-01-01

Reverse phase HPLC coupled to negative mode electrospray ionization (ESI) mass spectrometry (MS) was used to quantify 16 flavonoids and 2 phenolic acids from almond skin extracts. Calibration curves of standard compounds were run daily and daidzein was used as an internal standard. The inter-day relative standard deviation (RSD) of standard curve slopes ranged from 13% to 25% of the mean. On column (OC) limits of detection (LOD) for polyphenols ranged from 0.013 to 1.4 pmol, and flavonoid glycosides had a 7-fold greater sensitivity than aglycones. Limits of quantification were 0.043 to 2.7 pmol OC, with a mean of 0.58 pmol flavonoid OC. Mean inter-day RSD of polyphenols in almond skin extract was 6.8% with a range of 4% to 11%, and intra-day RSD was 2.4%. Liquid nitrogen (LN(2)) or hot water (HW) blanching was used to facilitate removal of the almond skins prior to extraction using assisted solvent extraction (ASE) or steeping with acidified aqueous methanol. Recovery of polyphenols was greatest in HW blanched almond extracts with a mean value of 2.1 mg/g skin. ASE and steeping extracted equivalent polyphenols, although ASE of LN(2) blanched skins yielded 52% more aglycones and 23% less flavonoid glycosides. However, the extraction methods did not alter flavonoid profile of HW blanched almond skins. The recovery of polyphenolic components that were spiked into almond skins before the steeping extraction was 97% on a mass basis. This LC-MS method presents a reliable means of quantifying almond polyphenols.

Quantification of Almond Skin Polyphenols by Liquid Chromatography-Mass Spectrometry

PubMed Central

Bolling, Bradley W.; Dolnikowski, Gregory; Blumberg, Jeffrey B.; Oliver Chen, C.Y.

2014-01-01

Reverse phase HPLC coupled to negative mode electrospray ionization (ESI) mass spectrometry (MS) was used to quantify 16 flavonoids and 2 phenolic acids from almond skin extracts. Calibration curves of standard compounds were run daily and daidzein was used as an internal standard. The inter-day relative standard deviation (RSD) of standard curve slopes ranged from 13% to 25% of the mean. On column (OC) limits of detection (LOD) for polyphenols ranged from 0.013 to 1.4 pmol, and flavonoid glycosides had a 7-fold greater sensitivity than aglycones. Limits of quantification were 0.043 to 2.7 pmol OC, with a mean of 0.58 pmol flavonoid OC. Mean inter-day RSD of polyphenols in almond skin extract was 6.8% with a range of 4% to 11%, and intra-day RSD was 2.4%. Liquid nitrogen (LN2) or hot water (HW) blanching was used to facilitate removal of the almond skins prior to extraction using assisted solvent extraction (ASE) or steeping with acidified aqueous methanol. Recovery of polyphenols was greatest in HW blanched almond extracts with a mean value of 2.1 mg/g skin. ASE and steeping extracted equivalent polyphenols, although ASE of LN2 blanched skins yielded 52% more aglycones and 23% less flavonoid glycosides. However, the extraction methods did not alter flavonoid profile of HW blanched almond skins. The recovery of polyphenolic components that were spiked into almond skins before the steeping extraction was 97% on a mass basis. This LC-MS method presents a reliable means of quantifying almond polyphenols. PMID:19490319

Extract-filter-shoot liquid chromatography/mass spectrometry for analysis of vitamin D2 in a powdered supplement capsule and SRM 3280

USDA-ARS?s Scientific Manuscript database

An ‘extract-filter-shoot’ method for analysis of vitamin D2, ergocalciferol, in a dry powdered dietary supplement capsule containing rice flour excipient and in National Institute of Standards and Technology (NIST) standard reference material (SRM) 3280 is reported. Quantification of vitamin D2 was...

Densitometric thin-layer chromatographic determination of aescin in a herbal medicinal product containing Aesculus and Vitis dry extracts.

PubMed

Apers, Sandra; Naessens, Tania; Pieters, Luc; Vlietinck, Arnold

2006-04-21

A thin-layer chromatographic (TLC) method is developed to analyze the total saponin content, also referred to as the aescin content, in a herbal medicinal product (HMP) containing two dry extracts in capsules. The capsules contain 250 mg of Aesculus hippocastanum dry extract, 120 mg of Vitis vinifera dry extract and 50mg of excipients. After a purification step using C(18) solid phase extraction (SPE) cartridges, the samples are analyzed on a silica-gel HPTLC plate with the upper layer of a mixture of acetic acid/water/butanol (10/40/50 v/v/v) as the mobile phase. Spots are visualized by spraying with anisaldehyde reagent and heating the plate for 5-10 min (100-105 degrees C) and measured at a wavelength of 535 nm. This method, applicable for the quality control and stability investigation of both the Aesculus dry extract and HMP capsules thereof containing Vitis dry extract in combination with the Aesculus dry extract, is validated according to the International Conference on Harmonization (ICH) guidelines. The proposed assay method is specific for aescin in the presence of Vitis dry extract and formulation excipients. Analysis of stressed samples in forced degradation tests proves the method to be applicable for stability evaluation. The standard aescin curve is linear (r > 0.99) over a concentration range of 0.16-0.80 microg/spot. Recovery from the HMP capsules is statistically equal to 100%. The precision of the method with respect to time and concentration is acceptable, with relative standard deviation (RSD) values of 1.28 and 1.49%, respectively.

40 CFR 98.224 - Monitoring and QA/QC requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Inorganic Emissions by Extractive Fourier Transform Infrared (FTIR) Spectroscopy. (2) ASTM D6348-03 Standard Test Method for Determination of Gaseous Compounds by Extractive Direct Interface Fourier Transform...

40 CFR 98.224 - Monitoring and QA/QC requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Inorganic Emissions by Extractive Fourier Transform Infrared (FTIR) Spectroscopy. (2) ASTM D6348-03 Standard Test Method for Determination of Gaseous Compounds by Extractive Direct Interface Fourier Transform...

40 CFR 98.224 - Monitoring and QA/QC requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Inorganic Emissions by Extractive Fourier Transform Infrared (FTIR) Spectroscopy. (2) ASTM D6348-03 Standard Test Method for Determination of Gaseous Compounds by Extractive Direct Interface Fourier Transform...

40 CFR 98.224 - Monitoring and QA/QC requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Inorganic Emissions by Extractive Fourier Transform Infrared (FTIR) Spectroscopy. (2) ASTM D6348-03 Standard Test Method for Determination of Gaseous Compounds by Extractive Direct Interface Fourier Transform...

Analysis of hydrazine in drinking water by isotope dilution gas chromatography/tandem mass spectrometry with derivatization and liquid-liquid extraction.

PubMed

Davis, William E; Li, Yongtao

2008-07-15

A new isotope dilution gas chromatography/chemical ionization/tandem mass spectrometric method was developed for the analysis of carcinogenic hydrazine in drinking water. The sample preparation was performed by using the optimized derivatization and multiple liquid-liquid extraction techniques. Using the direct aqueous-phase derivatization with acetone, hydrazine and isotopically labeled hydrazine-(15)N2 used as the surrogate standard formed acetone azine and acetone azine-(15)N2, respectively. These derivatives were then extracted with dichloromethane. Prior to analysis using methanol as the chemical ionization reagent gas, the extract was dried with anhydrous sodium sulfate, concentrated through evaporation, and then fortified with isotopically labeled N-nitrosodimethylamine-d6 used as the internal standard to quantify the extracted acetone azine-(15)N2. The extracted acetone azine was quantified against the extracted acetone azine-(15)N2. The isotope dilution standard calibration curve resulted in a linear regression correlation coefficient (R) of 0.999. The obtained method detection limit was 0.70 ng/L for hydrazine in reagent water samples, fortified at a concentration of 1.0 ng/L. For reagent water samples fortified at a concentration of 20.0 ng/L, the mean recoveries were 102% with a relative standard deviation of 13.7% for hydrazine and 106% with a relative standard deviation of 12.5% for hydrazine-(15)N2. Hydrazine at 0.5-2.6 ng/L was detected in 7 out of 13 chloraminated drinking water samples but was not detected in the rest of the chloraminated drinking water samples and the studied chlorinated drinking water sample.

Advantages of a validated UPLC-MS/MS standard addition method for the quantification of A-type dimeric and trimeric proanthocyanidins in cranberry extracts in comparison with well-known quantification methods.

PubMed

van Dooren, Ines; Foubert, Kenn; Theunis, Mart; Naessens, Tania; Pieters, Luc; Apers, Sandra

2018-01-30

The berries of Vaccinium macrocarpon, cranberry, are widely used for the prevention of urinary tract infections. This species contains A-type proanthocyanidins (PACs), which intervene in the initial phase of the development of urinary tract infections by preventing the adherence of Escherichia coli by their P-type fimbriae to uroepithelial cells. Unfortunately, the existing clinical studies used different cranberry preparations, which were poorly standardized. Because of this, the results were hard to compare, which led sometimes to conflicting results. Currently, PACs are quantified using the rather non-specific spectrophotometric 4-dimethylaminocinnamaldehyde (DMAC) method. In addition, a normal phase HPTLC-densitometric method, a HPLC-UV method and three LC-MS/MS methods for quantification of procyanidin A2 were recently published. All these methods contain some shortcomings and errors. Hence, the development and validation of a fast and sensitive standard addition LC-MS/MS method for the simultaneous quantification of A-type dimers and trimers in a cranberry dry extract was carried out. A linear calibration model could be adopted for dimers and, after logaritmic transformation, for trimers. The maximal interday and interconcentration precision was found to be 4.86% and 4.28% for procyanidin A2, and 5.61% and 7.65% for trimeric PACs, which are all acceptable values for an analytical method using LC-MS/MS. In addition, twelve different cranberry extracts were analyzed by means of the newly validated method and other widely used methods. There appeared to be an enormous variation in dimeric and trimeric PAC content. Comparison of these results with LC-MS/MS analysis without standard addition showed the presence of matrix effects for some of the extracts and proved the necessity of standard addition. A comparison of the well-known and widely used DMAC method, the butanol-HCl assay and this newly developed LC-MS/MS method clearly indicated the need for a reliable method able to quantify A-type PACs, which are considered to be the pharmacologically active constituents of cranberry, since neither the DMAC or butanol-HCl assays are capable of distinguishing between A and B-type PACs and therefore cannot detect adulterations with, for example, extracts with a high B-type PAC content. Hence, the combination of the DMAC method or butanol-HCl assay with this more specific LC-MS/MS assay could overcome these shortcomings. Copyright © 2017 Elsevier B.V. All rights reserved.

A simple and fast method for extraction and quantification of cryptophyte phycoerythrin.

PubMed

Thoisen, Christina; Hansen, Benni Winding; Nielsen, Søren Laurentius

2017-01-01

The microalgal pigment phycoerythrin (PE) is of commercial interest as natural colorant in food and cosmetics, as well as fluoroprobes for laboratory analysis. Several methods for extraction and quantification of PE are available but they comprise typically various extraction buffers, repetitive freeze-thaw cycles and liquid nitrogen, making extraction procedures more complicated. A simple method for extraction of PE from cryptophytes is described using standard laboratory materials and equipment. The cryptophyte cells on the filters were disrupted at -80 °C and added phosphate buffer for extraction at 4 °C followed by absorbance measurement. The cryptophyte Rhodomonas salina was used as a model organism. •Simple method for extraction and quantification of phycoerythrin from cryptophytes.•Minimal usage of equipment and chemicals, and low labor costs.•Applicable for industrial and biological purposes.

Validation of a quantitative NMR method for suspected counterfeit products exemplified on determination of benzethonium chloride in grapefruit seed extracts.

PubMed

Bekiroglu, Somer; Myrberg, Olle; Ostman, Kristina; Ek, Marianne; Arvidsson, Torbjörn; Rundlöf, Torgny; Hakkarainen, Birgit

2008-08-05

A 1H-nuclear magnetic resonance (NMR) spectroscopy method for quantitative determination of benzethonium chloride (BTC) as a constituent of grapefruit seed extract was developed. The method was validated, assessing its specificity, linearity, range, and precision, as well as accuracy, limit of quantification and robustness. The method includes quantification using an internal reference standard, 1,3,5-trimethoxybenzene, and regarded as simple, rapid, and easy to implement. A commercial grapefruit seed extract was studied and the experiments were performed on spectrometers operating at two different fields, 300 and 600 MHz for proton frequencies, the former with a broad band (BB) probe and the latter equipped with both a BB probe and a CryoProbe. The concentration average for the product sample was 78.0, 77.8 and 78.4 mg/ml using the 300 BB probe, the 600MHz BB probe and CryoProbe, respectively. The standard deviation and relative standard deviation (R.S.D., in parenthesis) for the average concentrations was 0.2 (0.3%), 0.3 (0.4%) and 0.3mg/ml (0.4%), respectively.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Faye, Sherry A.; Richards, Jason M.; Gallardo, Athena M.

Sequential extraction is a useful technique for assessing the potential to leach actinides from soils; however, current literature lacks uniformity in experimental details, making direct comparison of results impossible. This work continued development toward a standardized five-step sequential extraction protocol by analyzing extraction behaviors of 232Th, 238U, 239,240Pu and 241Am from lake and ocean sediment reference materials. Results produced a standardized procedure after creating more defined reaction conditions to improve method repeatability. A NaOH fusion procedure is recommended following sequential leaching for the complete dissolution of insoluble species.

Determination of low molecular weight alcohols including fusel oil in various samples by diethyl ether extraction and capillary gas chromatography.

PubMed

Woo, Kang-Lyung

2005-01-01

Low molecular weight alcohols including fusel oil were determined using diethyl ether extraction and capillary gas chromatography. Twelve kinds of alcohols were successfully resolved on the HP-FFAP (polyethylene glycol) capillary column. The diethyl ether extraction method was very useful for the analysis of alcohols in alcoholic beverages and biological samples with excellent cleanliness of the resulting chromatograms and high sensitivity compared to the direct injection method. Calibration graphs for all standard alcohols showed good linearity in the concentration range used, 0.001-2% (w/v) for all alcohols. Salting out effects were significant (p < 0.01) for the low molecular weight alcohols methanol, isopropanol, propanol, 2-butanol, n-butanol and ethanol, but not for the relatively high molecular weight alcohols amyl alcohol, isoamyl alcohol, and heptanol. The coefficients of variation of the relative molar responses were less than 5% for all of the alcohols. The limits of detection and quantitation were 1-5 and 10-60 microg/L for the diethyl ether extraction method, and 10-50 and 100-350 microg/L for the direct injection method, respectively. The retention times and relative retention times of standard alcohols were significantly shifted in the direct injection method when the injection volumes were changed, even with the same analysis conditions, but they were not influenced in the diethyl ether extraction method. The recoveries by the diethyl ether extraction method were greater than 95% for all samples and greater than 97% for biological samples.

Development of Conductivity Method as an Alternative to Titration for Hydrolytic Resistance Testing Used for Evaluation of Glass Vials Used in Pharmaceutical Industry.

PubMed

Fujimori, Kiyoshi; Lee, Hans; Phillips, Joseph; Nashed-Samuel, Yasser

The European Pharmacopeia surface test to analyze the hydrolytic resistance is a common industrial method to understand and ensure the quality of produced glass vials. Hydrolytic resistance is evaluated by calculating the alkalinity of water extract from autoclaved vials by titration. As an alternative to this titration technique, a conductivity technique was assessed, which directly measures the ions in the water extract. A conductivity meter with a 12 mm diameter electrode was calibrated with a 100 μS/cm conductivity standard and carryover minimized by rinsing the probe in a water beaker per analysis. The limit of quantification at 1 μS/cm was determined as having a signal-to-noise ratio of 3 compared with the water blank. The conductivity method was selective for glass-composing elements (boron, sodium, aluminum, silicon, potassium, and calcium) within the vial extract. Accuracies of spiked conductivity standard within the range of 1 to 100 μS/cm were ±7% and had linearity with coefficient of determination (R 2 ) of ≥0.9999. Intraday precision had a relative standard deviation (RSD) (n = 5) of ≤6% for spiked conductivity standard within the range of 1 to 100 μS/cm. Interday precision had a RSD (n = 4) of ≤6% for 10 vials from three glass vial lots. Conductivity of water extracts from nine sets of seven lots of glass vials had a precise linear relationship [R 2 = 0.9876, RSD = 1% (n = 9)] with titration volumes of the same lots. Conductivity results in μS/cm could be converted to titration volumes in milliliters by a conversion factor of 0.0275. The simplicity, sample stability, and individual vial analysis of the conductivity technique were more advantageous than the current titration technique. The quality of glass vials used as primary containers in the pharmaceutical industry is of concern due to recent observations of glass flake-like delamination, or lamellae, under specific storage conditions. The current European Pharmacopoeia method to assess glass vial quality utilizes acid titration of vial extract pools to determine hydrolytic resistance or alkalinity. As an alternative to the European Pharmacopoeia method, the vial extracts were analyzed for conductivity, which directly determines the level of ions that were readily extracted from the vial surfaces. Lower quality glass would have greater surface defects that lead to higher ions extracted and higher conductivity value. The conductivity method was found to be suitable to measure the ions in water extracts and showed strong correlation with alkalinity. The advantage of the conductivity method over the alkalinity method was greater ease, lower volume requirements, stability, and flexibility in analysis. © PDA, Inc. 2017.

Analysis of drugs in human tissues by supercritical fluid extraction/immunoassay

NASA Astrophysics Data System (ADS)

Furton, Kenneth G.; Sabucedo, Alberta; Rein, Joseph; Hearn, W. L.

1997-02-01

A rapid, readily automated method has been developed for the quantitative analysis of phenobarbital from human liver tissues based on supercritical carbon dioxide extraction followed by fluorescence enzyme immunoassay. The method developed significantly reduces sample handling and utilizes the entire liver homogenate. The current method yields comparable recoveries and precision and does not require the use of an internal standard, although traditional GC/MS confirmation can still be performed on sample extracts. Additionally, the proposed method uses non-toxic, inexpensive carbon dioxide, thus eliminating the use of halogenated organic solvents.

[Study on extraction of the total saponins of Chinese yam].

PubMed

Zhang, Min; Du, Lin; Huang, Gui-dong; Zhong, Xian-feng

2007-07-01

A method for the determination of total saponins of Chinese yam was established. The dioscin was used as a standard compound, the vanillin-perchloric acid as chromogenic agent and glacial acetic acid as solvent. The extraction technique of asponins from Chinese yam was studied by spectrometric method. Extracting temperature, extracting time, ethanol concentration and the ratio of raw material and water were selected as four factors to design the orthogonal test, and the optical condition of extraction was obtained. The results showed that the optical condition of extraction was as following: extracting temperature 60 degrees C, extracting time 6 h, ethanol concetration 80%, and the ratio of raw material and water 1:8.

Comparing Standard and Selective Degradation DNA Extraction Methods: Results from a Field Experiment with Sexual Assault Kits^.

PubMed

Campbell, Rebecca; Pierce, Steven J; Sharma, Dhruv B; Shaw, Jessica; Feeney, Hannah; Nye, Jeffrey; Schelling, Kristin; Fehler-Cabral, Giannina

2017-01-01

A growing number of U.S. cities have large numbers of untested sexual assault kits (SAKs) in police property facilities. Testing older kits and maintaining current case work will be challenging for forensic laboratories, creating a need for more efficient testing methods. We evaluated selective degradation methods for DNA extraction using actual case work from a sample of previously unsubmitted SAKs in Detroit, Michigan. We randomly assigned 350 kits to either standard or selective degradation testing methods and then compared DNA testing rates and CODIS entry rates between the two groups. Continuation-ratio modeling showed no significant differences, indicating that the selective degradation method had no decrement in performance relative to customary methods. Follow-up equivalence tests indicated that CODIS entry rates for the two methods could differ by more than ±5%. Selective degradation methods required less personnel time for testing and scientific review than standard testing. © 2016 American Academy of Forensic Sciences.

Evaluation of extraction methods for hexavalent chromium determination in dusts, ashes, and soils

USGS Publications Warehouse

Wolf, Ruth E.; Wilson, Stephen A.

2010-01-01

One of the difficulties in performing speciation analyses on solid samples is finding a suitable extraction method. Traditional methods for extraction of hexavalent chromium, Cr(VI), in soils, such as SW846 Method 3060A, can be tedious and are not always compatible with some determination methods. For example, the phosphate and high levels of carbonate and magnesium present in the U.S. Environmental Protection Agency (USEPA) Method 3060A digestion for Cr(VI) were found to be incompatible with the High Performance Liquid Chromatography-Inductively Coupled Plasma-Mass Spectrometry (HPLC-ICP-MS) detection method used by our laboratory. Modification of Method 3060A by eliminating the use of the phosphate buffer provided improved performance with the detection method, however dilutions are still necessary to achieve good chromatographic separation and detection of Cr(VI). An ultrasonic extraction method using a 1 mM Na2CO3 - 9 mM NaHCO3 buffer solution, adapted from Occupational Safety and Health Administration (OSHA) Method ID215, has been used with good results for the determination of Cr(VI) in air filters. The average recovery obtained for BCR-545 - Welding Dust Loaded on Filter (IRMM, Belgium) using this method was 99 percent (1.2 percent relative standard deviation) with no conversion of Cr(VI) to Cr(III) during the extraction process. This ultrasonic method has the potential for use with other sample matrices, such as ashes and soils. Preliminary investigations using NIST 2701 (Hexavalent Chromium in Contaminated Soil) loaded onto quartz filters showed promising results with approximately 90 percent recovery of the certified Cr(VI) value. Additional testing has been done using NIST 2701 and NIST 2700 using different presentation methods. Extraction efficiency of bulk presentation, where small portions of the sample are added to the bottom of the extraction vessel, will be compared with supported presentation, where small portions of the sample are loaded onto a quartz filter prior to extraction. In addition, results obtained from the standard grinding preparation of NIST 2701 and NIST 2700 will be compared with micronizing to reduce particle size before extraction.

Contact resistance extraction methods for short- and long-channel carbon nanotube field-effect transistors

NASA Astrophysics Data System (ADS)

Pacheco-Sanchez, Anibal; Claus, Martin; Mothes, Sven; Schröter, Michael

2016-11-01

Three different methods for the extraction of the contact resistance based on both the well-known transfer length method (TLM) and two variants of the Y-function method have been applied to simulation and experimental data of short- and long-channel CNTFETs. While for TLM special CNT test structures are mandatory, standard electrical device characteristics are sufficient for the Y-function methods. The methods have been applied to CNTFETs with low and high channel resistance. It turned out that the standard Y-function method fails to deliver the correct contact resistance in case of a relatively high channel resistance compared to the contact resistances. A physics-based validation is also given for the application of these methods based on applying traditional Si MOSFET theory to quasi-ballistic CNTFETs.

A new standardized method for quantification of humic and fulvic acids in humic ores and commercial products.

PubMed

Lamar, Richard T; Olk, Daniel C; Mayhew, Lawrence; Bloom, Paul R

2014-01-01

Increased use of humic substances in agriculture has generated intense interest among producers, consumers, and regulators for an accurate and reliable method to quantify humic acid (HA) and fulvic acid (FA) in raw ores and products. Here we present a thoroughly validated method, the new standardized method for determination of HA and FA contents in raw humate ores and in solid and liquid products produced from them. The methods used for preparation of HA and FA were adapted according to the guidelines of the International Humic Substances Society involving alkaline extraction followed by acidification to separate HA from the fulvic fraction. This is followed by separation of FA from the fulvic fraction by adsorption on a nonionic macroporous acrylic ester resin at acid pH. It differs from previous methods in that it determines HA and FA concentrations gravimetrically on an ash-free basis. Critical steps in the method, e.g., initial test portion mass, test portion to extract volume ratio, extraction time, and acidification of alkaline extract, were optimized for maximum and consistent recovery of HA and FA. The method detection limits for HA and FA were 4.62 and 4.8 mg/L, respectively. The method quantitation limits for HA and FA were 14.7 and 15.3 mg/L, respectively.

Angiotensin-converting enzyme (ACE) inhibitory potential of standardized Mucuna pruriens seed extract.

PubMed

Chaudhary, Sushil Kumar; De, Apurba; Bhadra, Santanu; Mukherjee, Pulok K

2015-01-01

Mucuna pruriens Linn. (Fabaceae) is a tropical legume, traditionally used for controlling blood pressure. Inhibition of angiotensin-converting enzyme (ACE) is one of the successful strategies for controlling hypertension. The present study evaluated the ACE inhibition potential of the standardized extract of M. pruriens seeds. Standardization of the extract and its fractions were carried out by RP-HPLC method [methanol and 1% v/v acetic acid in water (5:95 v/v)] using levodopa as a marker. The ACE inhibition activity of the extract and fractions was evaluated at different concentrations (20, 40, 60, 80, and 100 µg/mL) using the HPLC-DAD and the UV spectrophotometric method. The liberation of hippuric acid (HA) from hippuryl-L-histidyl-L-leucine (HHL) was estimated in the spectrophotometric method and RP-HPLC assay at 228 nm. Methanol extract and aqueous fraction showed a maximum activity with IC50 values of 38.44 ± 0.90 and 57.07 ± 2.90 µg/mL (RP-HPLC), and 52.68 ± 2.02 and 67.65 ± 2.40 µg/mL (spectrophotometry), respectively. The study revealed that the aqueous extract contains the highest amount of levodopa. Eventually the methanol extract showed highest ACE inhibition activity except levodopa alone. It was further observed that the inhibition was altered with respect to the change in the content of levodopa in the extract. Thus, it can be assumed that levodopa may be responsible for the ACE inhibition activity of M. pruriens seeds. It can be concluded that M. pruriens seed is a potential ACE inhibitor can be explored further as an effective antihypertensive agent.

Extraction and determination of total flavonoids in jujube by alcohol extraction

NASA Astrophysics Data System (ADS)

Ji, Y. B.; Ru, X.; Yu, M.; Wang, S. W.; Lu, L.; Qiao, A. N.; Guo, A. Z.

2017-12-01

Jujube is a ripe fruit of Rhamnaceae. Its main active component is flavonoids, so the extraction and determination of total flavonoids in jujube will help to develop and utilize the medicinal value of jujube. In this study, the total flavonoids were extracted from jujube by alcohol extraction method. Through single factor investigation and orthogonal test, it was found that the total flavonoids content in jujube was the highest under the condition of 70°C, material ratio of 1:40, and extraction of 30 min by 70% ethanol. The content of total flavonoids in the extract of jujube was 1.57% at the wavelength of 510 nm by UV and rutin as the standard. The method was evaluated by methodological study, and it was determined that this method could be used as the detection of total flavonoids in jujube extraction.

Screening of extraction methods for glycoproteins from jellyfish ( Rhopilema esculentum) oral-arms by high performance liquid chromatography

NASA Astrophysics Data System (ADS)

Ren, Guoyan; Li, Bafang; Zhao, Xue; Zhuang, Yongliang; Yan, Mingyan; Hou, Hu; Zhang, Xiukun; Chen, Li

2009-03-01

In order to select an optimum extraction method for the target glycoprotein (TGP) from jellyfish ( Rhopilema esculentum) oral-arms, a high performance liquid chromatography (HPLC)-assay for the determination of the TGP was developed. Purified target glycoprotein was taken as a standard glycoprotein. The results showed that the calibration curves for peak area plotted against concentration for TGP were linear ( r = 0.9984, y = 4.5895 x+47.601) over concentrations ranging from 50 to 400 mgL-1. The mean extraction recovery was 97.84% (CV2.60%). The fractions containing TGP were isolated from jellyfish ( R. esculentum) oral-arms by four extraction methods: 1) water extraction (WE), 2) phosphate buffer solution (PBS) extraction (PE), 3) ultrasound-assisted water extraction (UA-WE), 4) ultrasound-assisted PBS extraction (UA-PE). The lyophilized extract was dissolved in Milli-Q water and analyzed directly on a short TSK-GEL G4000PWXL (7.8 mm×300 mm) column. Our results indicated that the UA-PE method was the optimum extraction method selected by HPLC.

[Determination of heavy metals for RoHS compliance by ICP-OES spectrometry coupled with microwave extraction system].

PubMed

Hua, Li; Wu, Yi-Ping; An, Bing; Lai, Xiao-Wei

2008-11-01

The harm of heavy metals contained in electronic and electrical equipment (EEE) on environment is of high concern by human. Aiming to handle the great challenge of RoHS compliance, the determinations of trace or ultratrace chromium (Cr), cadmium (Cd), mercury (Hg) and lead (Pb) by inductively coupled plasma optical emission spectrometry (ICP-OES) was performed in the present paper, wherein, microwave extraction technology was used to prepare the sample solutions. In addition, the precision, recovery, repeatability and interference issues of this method were also discussed. The results exhibited that using the microwave extraction system to prepare samples is more quick, lossless, contamination-free in comparison with the conventional extraction methods such as dry ashing, wet-oven extraction etc. By analyzing the recoveries of these four heavy metals over different working time and wavelengths, the good recovery range between 85% and 115% showed that there was only tiny loss or contamination during the process of microwave extraction, sample introduction and ICP detection. Repeatability experiments proved that ICP plasma had a good stability during the working time and the matrix effect was small. Interference was a problem troublesome for atomic absorption spectrometry (AAS), however, the techniques of standard additions or inter-element correction (IEC) method can effectively eliminated the interferences of Ni, As, Fe etc. with the Cd determination. By employing the multi-wavelengths and two correction point methods, the issues of background curve sloping shift and spectra overlap were successfully overcome. Besides, for the determinations of trace heavy metal elements, the relative standard deviation (RSD) was less than 3% and the detection limits were less than 1 microg x L(-10 (3sigma, n = 5) for samples, standard solutions, and standard additions, which proved that ICP-OES has a good precision and high reliability. This provided a reliable technique support for electronic and electrical (EE) industries to comply with RoHS directive.

Contribution of calcium oxalate to soil-exchangeable calcium

USGS Publications Warehouse

Dauer, Jenny M.; Perakis, Steven S.

2013-01-01

Acid deposition and repeated biomass harvest have decreased soil calcium (Ca) availability in many temperate forests worldwide, yet existing methods for assessing available soil Ca do not fully characterize soil Ca forms. To account for discrepancies in ecosystem Ca budgets, it has been hypothesized that the highly insoluble biomineral Ca oxalate might represent an additional soil Ca pool that is not detected in standard measures of soil-exchangeable Ca. We asked whether several standard method extractants for soil-exchangeable Ca could also access Ca held in Ca oxalate crystals using spike recovery tests in both pure solutions and soil extractions. In solutions of the extractants ammonium chloride, ammonium acetate, and barium chloride, we observed 2% to 104% dissolution of Ca oxalate crystals, with dissolution increasing with both solution molarity and ionic potential of cation extractant. In spike recovery tests using a low-Ca soil, we estimate that 1 M ammonium acetate extraction dissolved sufficient Ca oxalate to contribute an additional 52% to standard measurements of soil-exchangeable Ca. However, in a high-Ca soil, the amount of Ca oxalate spike that would dissolve in 1 M ammonium acetate extraction was difficult to detect against the large pool of exchangeable Ca. We conclude that Ca oxalate can contribute substantially to standard estimates of soil-exchangeable Ca in acid forest soils with low soil-exchangeable Ca. Consequently, measures of exchangeable Ca are unlikely to fully resolve discrepancies in ecosystem Ca mass balance unless the contribution of Ca oxalate to exchangeable Ca is also assessed.

Validated Method for the Characterization and Quantification of Extractable and Nonextractable Ellagitannins after Acid Hydrolysis in Pomegranate Fruits, Juices, and Extracts.

PubMed

García-Villalba, Rocío; Espín, Juan Carlos; Aaby, Kjersti; Alasalvar, Cesarettin; Heinonen, Marina; Jacobs, Griet; Voorspoels, Stefan; Koivumäki, Tuuli; Kroon, Paul A; Pelvan, Ebru; Saha, Shikha; Tomás-Barberán, Francisco A

2015-07-29

Pomegranates are one of the main highly valuable sources of ellagitannins. Despite the potential health benefits of these compounds, reliable data on their content in pomegranates and derived extracts and food products is lacking, as it is usually underestimated due to their complexity, diversity, and lack of commercially available standards. This study describes a new method for the analysis of the extractable and nonextractable ellagitannins based on the quantification of the acid hydrolysis products that include ellagic acid, gallic acid, sanguisorbic acid dilactone, valoneic acid dilactone, and gallagic acid dilactone in pomegranate samples. The study also shows the occurrence of ellagitannin C-glycosides in pomegranates. The method was optimized using a pomegranate peel extract. To quantify nonextractable ellagitannins, freeze-dried pomegranate fruit samples were directly hydrolyzed with 4 M HCl in water at 90 °C for 24 h followed by extraction of the pellet with dimethyl sulfoxide/methanol (50:50, v/v). The method was validated and reproducibility was assessed by means of an interlaboratory trial, showing high reproducibility across six laboratories with relative standard deviations below 15%. Their applicability was demonstrated in several pomegranate extracts, different parts of pomegranate fruit (husk, peels, and mesocarp), and commercial juices. A large variability has been found in the ellagitannin content (150-750 mg of hydrolysis products/g) and type (gallagic acid/ellagic acid ratios between 4 and 0.15) of the 11 pomegranate extracts studied.

Extraction of total nucleic acid based on silica-coated magnetic particles for RT-qPCR detection of plant RNA virus/viroid.

PubMed

Sun, Ning; Deng, Congliang; Zhao, Xiaoli; Zhou, Qi; Ge, Guanglu; Liu, Yi; Yan, Wenlong; Xia, Qiang

2014-02-01

In this study, a nucleic acid extraction method based on silica-coated magnetic particles (SMPs) and RT-qPCR assay was developed to detect Arabis mosaic virus (ArMV), Lily symptomless virus (LSV), Hop stunt viroid (HSVd) and grape yellow speckle viroid 1 (GYSVd-1). The amplification sequences of RT-qPCR were reversely transcribed in vitro as RNA standard templates. The standard curves covered six or seven orders of magnitude with a detection limit of 100 copies per each assay. Extraction efficiency of the SMPs method was evaluated by recovering spiked ssRNAs from plant samples and compared to two commercial kits (TRIzol and RNeasy Plant mini kit). Results showed that the recovery rate of SMPs method was comparable to the commercial kits when spiked ssRNAs were extracted from lily leaves, whereas it was two or three times higher than commercial kits when spiked ssRNAs were extracted from grapevine leaves. SMPs method was also used to extract viral nucleic acid from15 ArMV-positive lily leaf samples and 15 LSV-positive lily leaf samples. SMPs method did not show statistically significant difference from other methods on detecting ArMV, but LSV. The SMPs method has the same level of virus load as the TRIzol, and its mean virus load of was 0.5log10 lower than the RNeasy Plant mini kit. Nucleic acid was extracted from 19 grapevine-leaf samples with SMPs and the two commercial kits and subsequently screened for HSVd and GYSVd-1 by RT-qPCR. Regardless of HSVd or GYSVd-1, SMPs method outperforms other methods on both positive rate and the viroid load. In conclusion, SMPs method was able to efficiently extract the nucleic acid of RNA viruses or viroids, especially grapevine viroids, from lily-leaf or grapevine-leaf samples for RT-qPCR detection. Copyright © 2013 Elsevier B.V. All rights reserved.

Application of fermentation for isoflavone extraction from soy molasses

NASA Astrophysics Data System (ADS)

Duru, K. C.; Kovaleva, E. G.; Glukhareva, T. V.

2017-09-01

Extraction of isoflavones from soy products remains a major challenge for researchers. Different extraction techniques have been employed but the need to use a cheap green extraction technique remains the main focus. This study applied fermentation of soy molasses using Saccharomyces cerevisiae for extraction of isoflavones and compared this technique to the conventional extraction method. The aluminum chloride colorimetric method was used for the determination of total flavonoid content of extracts. The highest yield was observed from extraction using ethyl acetate after fermentation of soy molasses and the lowest one was given by the extract from conventional extraction method. The DPPH radical scavenging activities of the extracts were also compared. The extract obtained using ethyl acetate after fermentation showed the highest antioxidant activity (0.0269 meq), while extract from conventional extraction had the lowest antioxidant activity (0.0055 meq). The effect of time on daidzein yield was studied using HPLC standard addition method. Daidzein concentration was higher in extract obtained at t = 80 min (3.82 ± 0.11 mg of daidzein /g of extract) as compared to that obtained at t = 60 min (2.89 ± 0.10 mg of daidzein /g of extract).

CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING DRINKING WATER SAMPLES FOR ANALYSIS OF PERSISTENT ORGANIC POLLUTANTS (SOP 5.23)

EPA Science Inventory

The method for extracting and preparing a drinking water sample for analysis of atrazine is summarized in this SOP. It covers the extraction and concentration of samples that are to be analyzed by gas chromatography/ mass spectrometry.

Development of an extraction method for perchlorate in soils.

PubMed

Cañas, Jaclyn E; Patel, Rashila; Tian, Kang; Anderson, Todd A

2006-03-01

Perchlorate originates as a contaminant in the environment from its use in solid rocket fuels and munitions. The current US EPA methods for perchlorate determination via ion chromatography using conductivity detection do not include recommendations for the extraction of perchlorate from soil. This study evaluated and identified appropriate conditions for the extraction of perchlorate from clay loam, loamy sand, and sandy soils. Based on the results of this evaluation, soils should be extracted in a dry, ground (mortar and pestle) state with Milli-Q water in a 1 ratio 1 soil ratio water ratio and diluted no more than 5-fold before analysis. When sandy soils were extracted in this manner, the calculated method detection limit was 3.5 microg kg(-1). The findings of this study have aided in the establishment of a standardized extraction method for perchlorate in soil.

SIMPLE METHOD FOR ESTIMATING POLYCHLORINATED BIPHENYL CONCENTRATIONS ON SOILS AND SEDIMENTS USING SUBCRITICAL WATER EXTRACTION COUPLED WITH SOLID-PHASE MICROEXTRACTION. (R825368)

EPA Science Inventory

A rapid method for estimating polychlorinated biphenyl (PCB) concentrations in contaminated soils and sediments has been developed by coupling static subcritical water extraction with solid-phase microextraction (SPME). Soil, water, and internal standards are placed in a seale...

PRELIMINARY COMPARATIVE STUDY OF METHODS TO EXTRACT VIRUS FROM RAW AND PROCESSED SEWAGE SLUDGES

EPA Science Inventory

Two simple virus extraction techniques were compared to an EPA standard method for detection of human enteric viruses in raw sewage sludge and class A biosolids. The techniques were used to detect both indigenous and seeded virus from a plant that distributes class A material pr...

Accurate Quantitation and Analysis of Nitrofuran Metabolites, Chloramphenicol, and Florfenicol in Seafood by Ultrahigh-Performance Liquid Chromatography-Tandem Mass Spectrometry: Method Validation and Regulatory Samples.

PubMed

Aldeek, Fadi; Hsieh, Kevin C; Ugochukwu, Obiadada N; Gerard, Ghislain; Hammack, Walter

2018-05-23

We developed and validated a method for the extraction, identification, and quantitation of four nitrofuran metabolites, 3-amino-2-oxazolidinone (AOZ), 3-amino-5-morpholinomethyl-2-oxazolidinone (AMOZ), semicarbazide (SC), and 1-aminohydantoin (AHD), as well as chloramphenicol and florfenicol in a variety of seafood commodities. Samples were extracted by liquid-liquid extraction techniques, analyzed by ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), and quantitated using commercially sourced, derivatized nitrofuran metabolites, with their isotopically labeled internal standards in-solvent. We obtained recoveries of 90-100% at various fortification levels. The limit of detection (LOD) was set at 0.25 ng/g for AMOZ and AOZ, 1 ng/g for AHD and SC, and 0.1 ng/g for the phenicols. Various extraction methods, standard stability, derivatization efficiency, and improvements to conventional quantitation techniques were also investigated. We successfully applied this method to the identification and quantitation of nitrofuran metabolites and phenicols in 102 imported seafood products. Our results revealed that four of the samples contained residues from banned veterinary drugs.

Determination of fluoroquinolones in cattle manure-based biogas residue by ultrasonic-enhanced microwave-assisted extraction followed by online solid phase extraction-ultra-high performance liquid chromatography-tandem mass spectrometry.

PubMed

Lu, Xue-Feng; Zhou, Yang; Zhang, Jian; Ren, Yu-Peng

2018-06-01

The present work describes the development and application of an ultrasonic-enhanced microwave-assisted extraction (UEMAE) followed by online solid phase extraction (SPE)-ultra-high performance liquid chromatography-tandem mass spectrometry method for the analysis of 14 fluoroquinolones in cattle manure-based biogas residue (CMBBR). The UEMAE was performed using the mixed solution of sodium dihydrogen phosphate and disodium ethylenediamine tetraacetic acid, avoiding use of any organic solvent. The online SPE system employed two solid phase extraction columns in a parallel manner, and the extraction was performed by passing 1 mL of the extract through the column. Quantification was performed using standard spiked samples and structural analogue internal standard, which were indispensable to reduce the matrix effects. Validation parameters were performed and good linearity (R 2  > 0.99 in all cases) and precision (inter- and intra-day relative standard deviations were lower than 12.8%) were obtained. Limits of detection were as low as 0.021 ng ∙ g -1 and lower limits of quantification were 0.5 ng ∙ g -1 for all fluoroquinolones. The overall extraction recovery, which was the product of the UEMAE recovery and the online SPE recovery, was assessed for three concentration levels (0.8, 40 and 400 ng ∙ g -1 ) and acceptable values (74.3-99.3%) were found. As a part of the method validation, the developed method has been used to analyze real CMBBR samples. Nine fluoroquinolones were found in the concentration range of 0.9-74.6 ng ∙ g -1 , while five were not detected in the samples. The results showed the method could be adapted for screening the presence or the final fate of fluoroquinolones during fermentation of animal waste. Copyright © 2018. Published by Elsevier B.V.

Determination of Wastewater Compounds in Sediment and Soil by Pressurized Solvent Extraction, Solid-Phase Extraction, and Capillary-Column Gas Chromatography/Mass Spectrometry

USGS Publications Warehouse

Burkhardt, Mark R.; Zaugg, Steven D.; Smith, Steven G.; ReVello, Rhiannon C.

2006-01-01

A method for the determination of 61 compounds in environmental sediment and soil samples is described. The method was developed in response to increasing concern over the effects of endocrine-disrupting chemicals in wastewater and wastewater-impacted sediment on aquatic organisms. This method also may be used to evaluate the effects of combined sanitary and storm-sewer overflow on the water and sediment quality of urban streams. Method development focused on the determination of compounds that were chosen on the basis of their endocrine-disrupting potential or toxicity. These compounds include the alkylphenol ethoxylate nonionic surfactants and their degradates, food additives, fragrances, antioxidants, flame retardants, plasticizers, industrial solvents, disinfectants, fecal sterols, polycyclic aromatic hydrocarbons, and high-use domestic pesticides. Sediment and soil samples are extracted using a pressurized solvent extraction system. The compounds of interest are extracted from interfering matrix components by high-pressure water/isopropyl alcohol extraction. The compounds were isolated using disposable solid-phase extraction (SPE) cartridges containing chemically modified polystyrene-divinylbenzene resin. The cartridges were dried with nitrogen gas, and then sorbed compounds were eluted with methylene chloride (80 percent)-diethyl ether (20 percent) through Florisil/sodium sulfate SPE cartridge, and then determined by capillary-column gas chromatography/mass spectrometry. Recoveries in reagent-sand samples fortified at 4 to 72 micrograms averaged 76 percent ?13 percent relative standard deviation for all method compounds. Initial method reporting levels for single-component compounds ranged from 50 to 500 micrograms per kilogram. The concentrations of 20 out of 61 compounds initially will be reported as estimated with the 'E' remark code for one of three reasons: (1) unacceptably low-biased recovery (less than 60 percent) or highly variable method performance (greater than 25 percent relative standard deviation), (2) reference standards prepared from technical mixtures, or (3) potential blank contamination. Samples were preserved by freezing to -20 degrees Celsius. The U.S. Geological Survey National Water Quality Laboratory has established a 1-year sample-holding time limit (prior to sample extraction) from the date of sample collection (if the sample is kept at -20?C) until a statistically accepted method can be used to determine the effectiveness of the sample-freezing procedure.

Screening of crude extracts of six medicinal plants used in South-West Nigerian unorthodox medicine for anti-methicillin resistant Staphylococcus aureus activity

PubMed Central

Akinyemi, Kabir O; Oladapo, Olukayode; Okwara, Chidi E; Ibe, Christopher C; Fasure, Kehinde A

2005-01-01

Background Six Nigerian medicinal plants Terminalia avicennioides, Phylantus discoideus, Bridella ferruginea, Ageratum conyzoides, Ocimum gratissimum and Acalypha wilkesiana used by traditional medical practitioners for the treatment of several ailments of microbial and non-microbial origins were investigated for in vitro anti-methicillin Resistant Staphylococcus aureus (MRSA) activity. Methods Fresh plant materials were collected from the users. Water and ethanol extracts of the shredded plants were obtained by standard methods. The Bacterial cultures used were strains of MRSA isolated from patients. MRSA was determined by the reference broth microdilution methods using the established National Committee for Clinical Laboratory Standards break points. Staphylococcus aureus NCIB 8588 was used as a standard strain. Susceptibility testing and phytochemical screening of the plant extracts were performed by standard procedures. Controls were maintained for each test batch. Results Both water and ethanol extracts of T. avicennioides, P. discoideus, O. gratissimum, and A. wilkesiana were effective on MRSA. The Minimum Inhibition Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the ethanol extracts of these plants range from 18.2 to 24.0 mcg/ml and 30.4 to 37.0 mcg/ml respectively. In contrast, MIC range of 30.6 to 43.0 mcg/ml and 55.4 to 71.0 mcg/ml were recorded for ethanol and water extracts of B. ferruginea, and A. conyzoides respectively. Higher MBC values were obtained for the two plants. These concentrations were too high to be considered active in this study. All the four active plants contained at least trace amount of anthraquinones. Conclusion Our results offer a scientific basis for the traditional use of water and ethanol extracts of A. wilkesiana, O. gratissimum, T. avicennioides and P. discoideus against MRSA-associated diseases. However, B. ferruginea and A. conyzoides were ineffective in vitro in this study; we therefore suggest the immediate stoppage of their traditional use against MRSA-associated diseases in Lagos, Nigeria. PMID:15762997

A comparative study: the impact of different lipid extraction methods on current microalgal lipid research

PubMed Central

2014-01-01

Microalgae cells have the potential to rapidly accumulate lipids, such as triacylglycerides that contain fatty acids important for high value fatty acids (e.g., EPA and DHA) and/or biodiesel production. However, lipid extraction methods for microalgae cells are not well established, and there is currently no standard extraction method for the determination of the fatty acid content of microalgae. This has caused a few problems in microlagal biofuel research due to the bias derived from different extraction methods. Therefore, this study used several extraction methods for fatty acid analysis on marine microalga Tetraselmis sp. M8, aiming to assess the potential impact of different extractions on current microalgal lipid research. These methods included classical Bligh & Dyer lipid extraction, two other chemical extractions using different solvents and sonication, direct saponification and supercritical CO2 extraction. Soxhlet-based extraction was used to weigh out the importance of solvent polarity in the algal oil extraction. Coupled with GC/MS, a Thermogravimetric Analyser was used to improve the quantification of microalgal lipid extractions. Among these extractions, significant differences were observed in both, extract yield and fatty acid composition. The supercritical extraction technique stood out most for effective extraction of microalgal lipids, especially for long chain unsaturated fatty acids. The results highlight the necessity for comparative analyses of microalgae fatty acids and careful choice and validation of analytical methodology in microalgal lipid research. PMID:24456581

Quality control of herbs: determination of amino acids in Althaea officinalis, Matricaria chamomilla and Taraxacum officinale.

PubMed

Qureshi, Muhammad Nasimullah; Stecher, Guenther; Bonn, Guenther Karl

2014-05-01

Analysis of raw materials and final products need reliable methods for the standardization of natural product drugs. Legal guideline also emphasizes on the qualitative and quantitative analyses of the plant constituents in an herbal product. In this study, thin layer chromatography (TLC) and amino acid analyzer was used for the determination of amino acids in plant extracts. Samples for this study were standards and aqueous extracts from Althaea officinalis, Matricaria chamomilla and Taraxacum officinale. Different amino acids in the extracts were detected through TLC. An automatic amino acid analyzer was used for the quantification of amino acids in the plant extracts under study.

Optimisation of a Naviglio-assisted extraction followed by determination of piperine content in Piper longum extracts.

PubMed

Gigliarelli, Giulia; Pagiotti, Rita; Persia, Diana; Marcotullio, Maria Carla

2017-01-01

Studies were made to increase the yield of piperine extraction using Naviglio Extractor® solid-liquid dynamic extractor (SLDE) from fruits of Piper longum. The effects of ratio w/v were investigated and optimised for the best method. The maximum yield of piperine (317.7 mg/g) from P. longum fruits was obtained in SLDE 1:50 ethanol extract. Extraction yields of piperine obtained from Soxhlet extraction, decotion (International Organization for Standardization) and conventional maceration extraction methods were found to be 233.7, 231.8 and 143.6 mg/g, respectively. The results of the present study indicated that Naviglio Extractor® is an effective technique for the extraction of piperine from long pepper.

A robust method for determining water-extractable alkylphenol polyethoxylates in textile products by reaction-based headspace gas chromatography.

PubMed

Zhang, Shu-Xin; Chai, Xin-Sheng; Huang, Bo-Xi; Mai, Xiao-Xia

2015-08-07

Alkylphenol polyethoxylates (APEO), surfactants used in the production of textiles, have the potential to move from the fabric to the skin of the person wearing the clothes, posing an inherent risk of adverse health consequences. Therefore, the textile industry needs a fast, robust method for determining aqueous extractable APEO in fabrics. The currently-favored HPLC methods are limited by the presence of a mixture of analytes (due to the molecular weight distribution) and a lack of analytical standards for quantifying results. As a result, it has not been possible to reach consensus on a standard method for the determination of APEO in textiles. This paper addresses these limitations through the use of reaction-based head space-gas chromatography (HS-GC). Specifically, water is used to simulate body sweat and extract APEO. HI is then used to react the ethoxylate chains to depolymerize the chains into iodoethane that is quantified through HS-GC, providing an estimate of the average amount of APEO in the clothing. Data are presented to justify the optimal operating conditions; i.e., water extraction at 60°C for 1h and reaction with a specified amount of HI in the headspace vial at 135°C for 4h. The results show that the HS-GC method has good precision (RSD<10%) and good accuracy (recoveries from 95 to 106%) for the quantification of APEO content in textile and related materials. As such, the method should be a strong candidate to become a standard method for such determinations. Copyright © 2015 Elsevier B.V. All rights reserved.

Improved Methods for Capture, Extraction, and Quantitative Assay of Environmental DNA from Asian Bigheaded Carp (Hypophthalmichthys spp.)

PubMed Central

Turner, Cameron R.; Miller, Derryl J.; Coyne, Kathryn J.; Corush, Joel

2014-01-01

Indirect, non-invasive detection of rare aquatic macrofauna using aqueous environmental DNA (eDNA) is a relatively new approach to population and biodiversity monitoring. As such, the sensitivity of monitoring results to different methods of eDNA capture, extraction, and detection is being investigated in many ecosystems and species. One of the first and largest conservation programs with eDNA-based monitoring as a central instrument focuses on Asian bigheaded carp (Hypophthalmichthys spp.), an invasive fish spreading toward the Laurentian Great Lakes. However, the standard eDNA methods of this program have not advanced since their development in 2010. We developed new, quantitative, and more cost-effective methods and tested them against the standard protocols. In laboratory testing, our new quantitative PCR (qPCR) assay for bigheaded carp eDNA was one to two orders of magnitude more sensitive than the existing endpoint PCR assays. When applied to eDNA samples from an experimental pond containing bigheaded carp, the qPCR assay produced a detection probability of 94.8% compared to 4.2% for the endpoint PCR assays. Also, the eDNA capture and extraction method we adapted from aquatic microbiology yielded five times more bigheaded carp eDNA from the experimental pond than the standard method, at a per sample cost over forty times lower. Our new, more sensitive assay provides a quantitative tool for eDNA-based monitoring of bigheaded carp, and the higher-yielding eDNA capture and extraction method we describe can be used for eDNA-based monitoring of any aquatic species. PMID:25474207

Improved methods for capture, extraction, and quantitative assay of environmental DNA from Asian bigheaded carp (Hypophthalmichthys spp.).

PubMed

Turner, Cameron R; Miller, Derryl J; Coyne, Kathryn J; Corush, Joel

2014-01-01

Indirect, non-invasive detection of rare aquatic macrofauna using aqueous environmental DNA (eDNA) is a relatively new approach to population and biodiversity monitoring. As such, the sensitivity of monitoring results to different methods of eDNA capture, extraction, and detection is being investigated in many ecosystems and species. One of the first and largest conservation programs with eDNA-based monitoring as a central instrument focuses on Asian bigheaded carp (Hypophthalmichthys spp.), an invasive fish spreading toward the Laurentian Great Lakes. However, the standard eDNA methods of this program have not advanced since their development in 2010. We developed new, quantitative, and more cost-effective methods and tested them against the standard protocols. In laboratory testing, our new quantitative PCR (qPCR) assay for bigheaded carp eDNA was one to two orders of magnitude more sensitive than the existing endpoint PCR assays. When applied to eDNA samples from an experimental pond containing bigheaded carp, the qPCR assay produced a detection probability of 94.8% compared to 4.2% for the endpoint PCR assays. Also, the eDNA capture and extraction method we adapted from aquatic microbiology yielded five times more bigheaded carp eDNA from the experimental pond than the standard method, at a per sample cost over forty times lower. Our new, more sensitive assay provides a quantitative tool for eDNA-based monitoring of bigheaded carp, and the higher-yielding eDNA capture and extraction method we describe can be used for eDNA-based monitoring of any aquatic species.

Validation of an optimized method for the determination of iodine in human breast milk by inductively coupled plasma mass spectrometry (ICPMS) after tetramethylammonium hydroxide extraction.

PubMed

Huynh, Dao; Zhou, Shao Jia; Gibson, Robert; Palmer, Lyndon; Muhlhausler, Beverly

2015-01-01

In this study a novel method to determine iodine concentrations in human breast milk was developed and validated. The iodine was analyzed by inductively coupled plasma mass spectrometry (ICPMS) following tetramethylammonium hydroxide (TMAH) extraction at 90°C in disposable polypropylene tubes. While similar approaches have been used previously, this method adopted a shorter extraction time (1h vs. 3h) and used antimony (Sb) as the internal standard, which exhibited greater stability in breast milk and milk powder matrices compared to tellurium (Te). Method validation included: defining iodine linearity up to 200μgL(-1); confirming recovery of iodine from NIST 1549 milk powder. A recovery of 94-98% was also achieved for the NIST 1549 milk powder and human breast milk samples spiked with sodium iodide and thyroxine (T4) solutions. The method quantitation limit (MQL) for human breast milk was 1.6μgL(-1). The intra-assay and inter-assay coefficient of variation for the breast milk samples and NIST powder were <1% and <3.5%, respectively. NIST 1549 milk powder, human breast milk samples and calibration standards spiked with the internal standard were all stable for at least 2.5 months after extraction. The results of the validation process confirmed that this newly developed method provides greater accuracy and precision in the assessment of iodine concentrations in human breast milk than previous methods and therefore offers a more reliable approach for assessing iodine concentrations in human breast milk. Copyright © 2014 Elsevier GmbH. All rights reserved.

Separation and quantitation of three acidic herbicide residues in tobacco and soil by dispersive solid-phase extraction and UPLC-MS/MS.

PubMed

Xiong, Wei; Tao, Xiaoqiu; Pang, Su; Yang, Xue; Tang, GangLing; Bian, Zhaoyang

2014-01-01

A method for the determination of three acidic herbicides, dicamba, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) in tobacco and soil has been developed based on the use of liquid-liquid extraction and dispersive solid-phase extraction (dispersive-SPE) followed by UPLC-MS/MS. Two percentage of (v/v) formic acid in acetonitrile as the extraction helped partitioning of analytes into the acetonitrile phase. The extract was then cleaned up by dispersive-SPE using primary secondary amine as selective sorbents. Quantitative analysis was done in the multiple-reaction monitoring mode using stable isotope-labeled internal standards for each compound. A separate internal standard for each analyte is required to minimize sample matrix effects on each analyte, which can lead to poor analyte recoveries and decreases in method accuracy and precision. The total analysis time was <4 min. The linear range of the method was from 1 to 100 ng mL(-1) with a limit of detection of each herbicide varied from 0.012 to 0.126 ng g(-1). The proposed method is faster, more sensitive and selective than the traditional methods and more accurate and robust than the published LC-MS/MS methods. © The Author [2013]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory : determination of polycyclic aromatic hydrocarbon compounds in sediment by gas chromatography/mass spectrometry

USGS Publications Warehouse

Olson, Mary C.; Iverson, Jana L.; Furlong, Edward T.; Schroeder, Michael P.

2004-01-01

A method for the determination of 28 polycyclic aromatic hydrocarbons (PAHs) and 25 alkylated PAH homolog groups in sediment samples is described. The compounds are extracted from sediment by solvent extraction, followed by partial isolation using high-performance gel permeation chromatography. The compounds are identified and uantitated using capillary-column gas chromatography/mass spectrometry. The report presents performance data for full-scan ion monitoring. Method detection limits in laboratory reagent matrix samples range from 1.3 to 5.1 micrograms per kilogram for the 28 PAHs. The 25 groups of alkylated PAHs are homologs of five groups of isomeric parent PAHs. Because of the lack of authentic standards, these homologs are reported semiquantitatively using a response factor from a parent PAH or a specific alkylated PAH. Precision data for the alkylated PAH homologs are presented using two different standard reference manuals produced by the National Institute of Standards and Technology: SRM 1941b and SRM 1944. The percent relative standard deviations for identified alkylated PAH homolog groups ranged from 1.55 to 6.98 for SRM 1941b and from 6.11 to 12.0 for SRM 1944. Homolog group concentrations reported under this method include the concentrations of individually identified compounds that are members of the group. Organochlorine (OC) pesticides--including toxaphene, polychlorinated biphenyls (PCBs), and organophosphate (OP) pesticides--can be isolated simultaneously using this method. In brief, sediment samples are centrifuged to remove excess water and extracted overnight with dichloromethan (95 percent) and methanol (5 percent). The extract is concentrated and then filtered through a 0.2-micrometer polytetrafluoroethylene syringe filter. The PAH fraction is isolated by quantitatively injecting an aliquot of sample onto two polystyrene-divinylbenzene gel-permeation chromatographic columns connected in series. The compounds are eluted with dichloromethane, a PAH fraction is collected, and a portion of the coextracted interferences, including elemental sulfur, is separated and discarded. The extract is solvent exchanged, the volume is reduced, and internal standard is added. Sample analysis is completed using a gas chromatograph/mass spectrometer and full-scan acquisition.

In vitro antimicrobial activity of ethanolic fractions of Cryptolepis sanguinolenta

PubMed Central

2012-01-01

Background Following claims that some plants have antimicrobial activities against infectious microbes, the in vitro antimicrobial activities of different solvent fractions of ethanolic extract of Cryptolepis sanguinolenta were evaluated against eight standard bacteria and clinical isolates. Methods The solvent partitioning protocol involving ethanol, petroleum ether, chloroform, ethyl acetate and water, was used to extract various fractions of dried pulverized Cryptolepis sanguinolenta roots. Qualitative phyto-constituents screening was performed on the ethanol extract, chloroform fraction and the water fraction. The Kirby Bauer disk diffusion method was employed to ascertain the antibiogram of the test organisms while the agar diffusion method was used to investigate the antimicrobial properties of the crude plant extracts. The microplate dilution method aided in finding the MICs while the MBCs were obtained by the method of Nester and friends. The SPSS 16.0 version was used to analyze the percentages of inhibitions and bactericidal activities. Results The phytochemical screening revealed the presence of alkaloids, reducing sugars, polyuronides, anthocyanosides and triterpenes. The ethanol extract inhibited 5 out of 8 (62.5%) of the standard organisms and 6 out of 8 (75%) clinical isolates. The petroleum ether fraction inhibited 4 out of 8 (50%) of the standard microbes and 1 out of 8 (12.5%) clinical isolates. It was also observed that the chloroform fraction inhibited the growth of all the organisms (100%). Average inhibition zones of 14.0 ± 1.0 mm to 24.67 ± 0.58 mm was seen in the ethyl acetate fraction which halted the growth of 3 (37.5%) of the standard organisms. Inhibition of 7 (87.5%) of standard strains and 6 (75%) of clinical isolates were observed in the water fraction. The chloroform fraction exhibited bactericidal activity against all the test organisms while the remaining fractions showed varying degrees of bacteriostatic activity. Conclusion The study confirmed that fractions of Cryptolepis sanguinolenta have antimicrobial activity. The chloroform fraction had the highest activity, followed by water, ethanol, petroleum ether and ethyl acetate respectively. Only the chloroform fraction exhibited bactericidal activity and further investigations are needed to ascertain its safety and prospects of drug development. PMID:22709723

Highly Effective DNA Extraction Method for Nuclear Short Tandem Repeat Testing of Skeletal Remains from Mass Graves

PubMed Central

Davoren, Jon; Vanek, Daniel; Konjhodzić, Rijad; Crews, John; Huffine, Edwin; Parsons, Thomas J.

2007-01-01

Aim To quantitatively compare a silica extraction method with a commonly used phenol/chloroform extraction method for DNA analysis of specimens exhumed from mass graves. Methods DNA was extracted from twenty randomly chosen femur samples, using the International Commission on Missing Persons (ICMP) silica method, based on Qiagen Blood Maxi Kit, and compared with the DNA extracted by the standard phenol/chloroform-based method. The efficacy of extraction methods was compared by real time polymerase chain reaction (PCR) to measure DNA quantity and the presence of inhibitors and by amplification with the PowerPlex 16 (PP16) multiplex nuclear short tandem repeat (STR) kit. Results DNA quantification results showed that the silica-based method extracted on average 1.94 ng of DNA per gram of bone (range 0.25-9.58 ng/g), compared with only 0.68 ng/g by the organic method extracted (range 0.0016-4.4880 ng/g). Inhibition tests showed that there were on average significantly lower levels of PCR inhibitors in DNA isolated by the organic method. When amplified with PP16, all samples extracted by silica-based method produced 16 full loci profiles, while only 75% of the DNA extracts obtained by organic technique amplified 16 loci profiles. Conclusions The silica-based extraction method showed better results in nuclear STR typing from degraded bone samples than a commonly used phenol/chloroform method. PMID:17696302

Measurement of water-soluble B vitamins in infant formula by liquid chromatography/tandem mass spectrometry.

PubMed

Huang, Min; Winters, Doug; Crowley, Richard; Sullivan, Darryl

2009-01-01

A method has been developed for the simultaneous measurement of multiple B vitamins (i.e., B1, B2, B3, B5, and B6) in infant formulas by LC-MSIMS. The vitamins were extracted with acidic solvent, followed by protein precipitation at a pH range of 4.5 to 5.5, and filtered. This simplified procedure eliminates many of the potential sources of laboratory error and facilitates rapid and efficient analysis. As is common in most cases, isotope internal standards were added to account for variations in sample preparation, as well as changes in MS measurement. In this method, isotope-labeled internal standards of B1, B3, B5, and B6 were used. The factors affecting analytical performance were investigated and optimized. In addition, the stability of these vitamins in the extraction solution was investigated. An acidic condition (5 mM HCl) was applied to successfully stabilize B1, which had shown a decrease in signal when other solvents were used. The quantitative extraction and good stability allowed isotope standards to be added to the filtered sample solution, instead of to the extraction solvent. The addition of the isotope to the small portion of the filtered sample solution significantly reduces cost. A comprehensive evaluation of the analysis of the standard reference material and good spike recovery of the vitamins (100 +/- 6%) demonstrates the accuracy of the method. The results for commercially available infant formula samples were also compared with those obtained using the current microbiological method.

[Simultaneous determination of trichloroethylene and trichloroethanol in blood by liquid-liquid extraction-gas chromatography].

PubMed

Ye, H P; Shao, J; Tan, S W; Shan, X Y; Shi, Y P

2017-10-20

Objective: To establish a method for determing the trichloroethylene(TCE)and trichloroethanol(TCOH)in blood samples by liquid-liquid extraction-gas chromatography with electron capture detector. Methods: With this method,ether was used as extraction solvent and trichloromethane was used as an internal standard. The whole blood sample was extracted with ether, and dehydrated by anhydrous sodium sulfate. Then the analytes were separated on HP-5 capillary column(30m×0.32mm×0.15μm)and detected byECD.The retention time was for qualitative analysis and the internal standard was for quantitation. Results: The standard curves of TCE and TCOH showed significant linearity between 95.5μg/L-7640.0μg/L( r =0.9997)and 19.0μg/L-1520.0μg/L( r =0.9992). The average recovery was 95.5%-103.6%.The intra-day and inter-day precisions( RSD )were 2.5%-6.8%( n =6)and 1.6%-4.3%( n =6) respectively. The detect limit of TCE and TCOH were 2.10 μg/L and 0.56μg/L(S/N=3)respectively.The blood can be kept 7 days at-20℃ refrigerator without significantly loss. Conclusion: This method is proved to be simple,practical and highly sensitive. It can satisfy the request for the determination of blood samples of humans exposed to TCE.

Recognition and defect detection of dot-matrix text via variation-model based learning

NASA Astrophysics Data System (ADS)

Ohyama, Wataru; Suzuki, Koushi; Wakabayashi, Tetsushi

2017-03-01

An algorithm for recognition and defect detection of dot-matrix text printed on products is proposed. Extraction and recognition of dot-matrix text contains several difficulties, which are not involved in standard camera-based OCR, that the appearance of dot-matrix characters is corrupted and broken by illumination, complex texture in the background and other standard characters printed on product packages. We propose a dot-matrix text extraction and recognition method which does not require any user interaction. The method employs detected location of corner points and classification score. The result of evaluation experiment using 250 images shows that recall and precision of extraction are 78.60% and 76.03%, respectively. Recognition accuracy of correctly extracted characters is 94.43%. Detecting printing defect of dot-matrix text is also important in the production scene to avoid illegal productions. We also propose a detection method for printing defect of dot-matrix characters. The method constructs a feature vector of which elements are classification scores of each character class and employs support vector machine to classify four types of printing defect. The detection accuracy of the proposed method is 96.68 %.

Cholesterol esterase inhibitory activity of bioactives from leaves of Mangifera indica L

PubMed Central

Gururaja, G. M.; Mundkinajeddu, Deepak; Dethe, Shekhar M.; Sangli, Gopala K.; Abhilash, K.; Agarwal, Amit

2015-01-01

Background: In the earlier studies, methanolic extract of Mangifera indica L leaf was exhibited hypocholesterol activity. However, the bioactive compounds responsible for the same are not reported so far. Objective: To isolate the bioactive compounds with hypocholesterol activity from the leaf extract using cholesterol esterase inhibition assay which can be used for the standardization of extract. Materials and Methods: The leaf methanolic extract of M. indica (Sindoora variety) was partitioned with ethyl acetate and chromatographed on silica gel to yield twelve fractions and the activity was monitored by using cholesterol esterase inhibition assay. Active fractions were re-chromatographed to yield individual compounds. Results and Discussion: A major compound mangiferin present in the extract was screened along with other varieties of mango leaves for cholesterol esterase inhibition assay. However, the result indicates that compounds other than mangiferin may be active in the extract. Invitro pancreatic cholesterol esterase inhibition assay was used for bioactivity guided fractionation (BAGF) to yield bioactive compound for standardization of extract. Bioactivity guided fractionation afford the active fraction containing 3b-taraxerol with an IC50 value of 0.86μg/ml. Conclusion: This study demonstrates that M. indica methanol extract of leaf have significant hypocholesterol activity which is standardized with 3b-taraxerol, a standardized extract for hypocholesterol activity resulted in development of dietary supplement from leaves of Mangifera indica. PMID:26692750

Development of an extractive spectrophotometric method for estimation of uranium in ore leach solutions using 2-ethylhexyl phosphonic acid-mono-2-ethylhexyl ester (PC88A) and tri-n-octyl phosphine oxide (TOPO) mixture as extractant and 2-(5-bromo-2-pyridylozo)-5-diethyl aminophenol (Br-PADAP) as chromophore

NASA Astrophysics Data System (ADS)

Biswas, Sujoy; Pathak, P. N.; Roy, S. B.

2012-06-01

An extractive spectrophotometric analytical method has been developed for the determination of uranium in ore leach solution. This technique is based on the selective extraction of uranium from multielement system using a synergistic mixture of 2-ethylhexyl phosphonic acid-mono-2-ethylhexyl ester (PC88A) and tri-n-octyl phosphine oxide (TOPO) in cyclohexane and color development from the organic phase aliquot using 2-(5-Bromo-2-pyridylazo)-5-diethyl aminophenol (Br-PADAP) as chromogenic reagent. The absorption maximum (λmax) for UO22+-Br-PADAP complex in organic phase samples, in 64% (v/v) ethanol containing buffer solution (pH 7.8) and 1,2-cyclohexylenedinitrilotetraacetic acid (CyDTA) complexing agent, has been found to be at 576 nm (molar extinction coefficient, ɛ: 36,750 ± 240 L mol-1 cm-1). Effects of various parameters like stability of complex, ethanol volume, ore matrix, interfering ions etc. on the determination of uranium have also been evaluated. Absorbance measurements as a function of time showed that colored complex is stable up to >24 h. Presence of increased amount of ethanol in colored solution suppresses the absorption of a standard UO22+-Br-PADAP solution. Analyses of synthetic standard as well as ore leach a solution show that for 10 determination relative standard deviation (RSD) is <2%. The accuracy of the developed method has been checked by determining uranium using standard addition method and was found to be accurate with a 98-105% recovery rate. The developed method has been applied for the analysis of a number of uranium samples generated from uranium ore leach solutions and results were compared with standard methods like inductively coupled plasma emission spectrometry (ICPAES). The determined values of uranium concentrations by these methods are within ±2%. This method can be used to determine 2.5-250 μg mL-1 uranium in ore leach solutions with high accuracy and precision.

Fuzzy clustering evaluation of the discrimination power of UV-Vis and (±) ESI-MS detection system in individual or coupled RPLC for characterization of Ginkgo Biloba standardized extracts.

PubMed

Medvedovici, Andrei; Albu, Florin; Naşcu-Briciu, Rodica Domnica; Sârbu, Costel

2014-02-01

Discrimination power evaluation of UV-Vis and (±) electrospray ionization/mass spectrometric techniques, (ESI-MS) individually considered or coupled as detectors to reversed phase liquid chromatography (RPLC) in the characterization of Ginkgo Biloba standardized extracts, is used in herbal medicines and/or dietary supplements with the help of Fuzzy hierarchical clustering (FHC). Seventeen batches of Ginkgo Biloba commercially available standardized extracts from seven manufacturers were measured during experiments. All extracts were within the criteria of the official monograph dedicated to dried refined and quantified Ginkgo extracts, in the European Pharmacopoeia. UV-Vis and (±) ESI-MS spectra of the bulk standardized extracts in methanol were acquired. Additionally, an RPLC separation based on a simple gradient elution profile was applied to the standardized extracts. Detection was made through monitoring UV absorption at 220 nm wavelength or the total ion current (TIC) produced through (±) ESI-MS analysis. FHC was applied to raw, centered and scaled data sets, for evaluating the discrimination power of the method with respect to the origins of the extracts and to the batch to batch variability. The discrimination power increases with the increase of the intrinsic selectivity of the spectral technique being used: UV-Vis

[Preparation of flavonoid reference standards from Scutellariae Radix under the guidance of high performance liquid chromatography-mass spectrometry analysis].

PubMed

Guo, Henan; Yang, Xuedong; Liu, Jun; Zheng, Wenfeng

2012-07-01

Flavonoid reference standards were targeted-prepared from Scutellariae Radix under the guidance of high performance liquid chromatography-mass spectrometry (HPLC-MS) analysis. With HPLC-MS analysis of Scutellariae Radix, 19 flavonoid components were identified by analyzing and comparing their retention times, ultraviolet spectra, and mass spectrometry data with literature. The separation and purification protocols of all targeted flavonoid reference standards were optimally designed according to the results of HPLC-MS analysis and related literature. The ethanol extract of Scutellariae Radix was suspended in water and extracted with petroleum ether, ethyl acetate, and n-butanol successively. The ethyl acetate extract and n-butanol extract were separately subjected to primary separation by low pressure reverse phase preparative chromatography. Then the fractions containing targeted compounds were further purified by low pressure reverse and normal phases preparative chromatography. Finally, baicalin and wogonoside reference standards were obtained from n-butanol extract; baicaelin, wogonin, and oroxylin A reference standards were obtained from ethyl acetate extract. The structures of the 5 reference standards were identified by mass spectrometry (MS) and 1H nuclear magnetic resonance (1H NMR) spectroscopy. The HPLC analytical results showed that the purities of the 5 reference standards were all above 98%. It is demonstrated that the rapid targeted-preparation method under the guidance of the HPLC-MS analysis is applicable for the isolation and preparation of chemical components in traditional Chinese medicines.

Research on oral test modeling based on multi-feature fusion

NASA Astrophysics Data System (ADS)

Shi, Yuliang; Tao, Yiyue; Lei, Jun

2018-04-01

In this paper, the spectrum of speech signal is taken as an input of feature extraction. The advantage of PCNN in image segmentation and other processing is used to process the speech spectrum and extract features. And a new method combining speech signal processing and image processing is explored. At the same time of using the features of the speech map, adding the MFCC to establish the spectral features and integrating them with the features of the spectrogram to further improve the accuracy of the spoken language recognition. Considering that the input features are more complicated and distinguishable, we use Support Vector Machine (SVM) to construct the classifier, and then compare the extracted test voice features with the standard voice features to achieve the spoken standard detection. Experiments show that the method of extracting features from spectrograms using PCNN is feasible, and the fusion of image features and spectral features can improve the detection accuracy.

CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING DUST AND SOIL SAMPLES FOR ANALYSIS OF NEUTRAL PERSISTENT ORGANIC POLLUTANTS (SOP-5.14)

EPA Science Inventory

This SOP summarizes the method for extracting and preparing a dust or soil sample for analysis of neutral persistent organic pollutants. It covers the extraction and concentration of samples that are to be analyzed by gas chromatography/mass spectrometry.

CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING DERMAL WIPE SAMPLES FOR ANALYSIS OF NEUTRAL PERSISTENT ORGANIC POLLUTANTS (SOP-5.16)

EPA Science Inventory

The method for extracting and preparing a dermal (hand) wipe sample for analysis of neutral persistent organic pollutants is summarized in this SOP. It covers the extraction and concentration of samples that are to be analyzed by gas chromatography/mass spectrometry.

Iodine speciation in coastal and inland bathing waters and seaweeds extracts using a sequential injection standard addition flow-batch method.

PubMed

Santos, Inês C; Mesquita, Raquel B R; Bordalo, Adriano A; Rangel, António O S S

2015-02-01

The present work describes the development of a sequential injection standard addition method for iodine speciation in bathing waters and seaweeds extracts without prior sample treatment. Iodine speciation was obtained by assessing the iodide and iodate content, the two inorganic forms of iodine in waters. For the determination of iodide, an iodide ion selective electrode (ISE) was used. The indirect determination of iodate was based on the spectrophotometric determination of nitrite (Griess reaction). For the iodate measurement, a mixing chamber was employed (flow batch approach) to explore the inherent efficient mixing, essential for the indirect determination of iodate. The application of the standard addition method enabled detection limits of 0.14 µM for iodide and 0.02 µM for iodate, together with the direct introduction of the target water samples, coastal and inland bathing waters. The results obtained were in agreement with those obtained by ICP-MS and a colorimetric reference procedure. Recovery tests also confirmed the accuracy of the developed method which was effectively applied to bathing waters and seaweed extracts. Copyright © 2014 Elsevier B.V. All rights reserved.

40 CFR 440.34 - New source performance standards (NSPS).

Code of Federal Regulations, 2011 CFR

2011-07-01

... uranium ore, excluding mines using in situ leach methods, shall not exceed: Effluent characteristic... for the extraction of uranium or from mines and mills using in situ leach methods. The Agency... Subcategory § 440.34 New source performance standards (NSPS). Except as provided in subpart L of this part any...

40 CFR 440.34 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... uranium ore, excluding mines using in situ leach methods, shall not exceed: Effluent characteristic... for the extraction of uranium or from mines and mills using in situ leach methods. The Agency... Subcategory § 440.34 New source performance standards (NSPS). Except as provided in subpart L of this part any...

Comparison of ophthalmic sponges and extraction buffers for quantifying cytokine profiles in tears using Luminex technology

PubMed Central

Inic-Kanada, Aleksandra; Nussbaumer, Andrea; Montanaro, Jacqueline; Belij, Sandra; Schlacher, Simone; Stein, Elisabeth; Bintner, Nora; Merio, Margarethe; Zlabinger, Gerhard J.

2012-01-01

Purpose Evaluating cytokine profiles in tears could shed light on the pathogenesis of various ocular surface diseases. When collecting tears with the methods currently available, it is often not possible to avoid the tear reflex, which may give a different cytokine profile compared to basal tears. More importantly, tear collection with glass capillaries, the most widely used method for taking samples and the best method for avoiding tear reflex, is impractical for remote area field studies because it is tedious and time-consuming for health workers, who cannot collect tears from a large number of patients with this method in one day. Furthermore, this method is uncomfortable for anxious patients and children. Thus, tears are frequently collected using ophthalmic sponges. These sponges have the advantage that they are well tolerated by the patient, especially children, and enable standardization of the tear collection volume. The aim of this study was to compare various ophthalmic sponges and extraction buffers to optimize the tear collection method for field studies for subsequent quantification of cytokines in tears using the Luminex technology. Methods Three ophthalmic sponges, Merocel, Pro-ophta, and Weck-Cel, were tested. Sponges were presoaked with 25 cytokines/chemokines of known concentrations and eluted with seven different extraction buffers (EX1–EX7). To assess possible interference in the assay from the sponges, two standard curves were prepared in parallel: 1) cytokines of known concentrations with the extraction buffers and 2) cytokines of known concentrations loaded onto the sponges with the extraction buffers. Subsequently, a clinical assessment of the chosen sponge-buffer combination was performed with tears collected from four healthy subjects using 1) aspiration and 2) sponges. To quantify cytokine/chemokine recovery and the concentration in the tears, a 25-plex Cytokine Panel and the Luminex xMap were used. This platform enables simultaneous measurement of proinflammatory cytokines, Th1/Th2 distinguishing cytokines, nonspecific acting cytokines, and chemokines. Results We demonstrated the following: (i) 25 cytokines/chemokines expressed highly variable interactions with buffers and matrices. Several buffers enabled recovery of similar cytokine values (regulated and normal T cell expressed and secreted [RANTES], interleukin [IL]-13, IL-6, IL-8, IL-2R, and granulocyte-macrophage colony-stimulating factor [GM-CSF]); others were highly variable (monocyte chemotactic protein-1 [MCP-1], monokine induced by interferon-gamma [MIG], IL-1β, IL-4, IL-7, and eotaxin). (ii) Various extraction buffers displayed significantly different recovery rates on the same sponge for the same cytokine/chemokine. (iii) The highest recovery rates were obtained with the Merocel ophthalmic sponge except for tumor necrosis factor-α: the Weck-Cel ophthalmic sponge showed the best results, either with cytokine standards loaded onto sponges or with tears collected from the inner canthus of the eye, using the sponge. (iv) IL-5, IL-10, and interferon-α were not detected in any tear sample from four normal human subjects. Twenty-two cytokines/chemokines that we detected were extracted from the Merocel sponge to a satisfactory recovery percentage. The recovery of IL-7 was significantly lower in the extracted Merocel sponge compared to the diluted tear samples. The cytokine/chemokine extraction from tears showed the same pattern of extraction that we observed for extracting the standards. Conclusions Simultaneous measurement of various cytokines using ophthalmic sponges yielded diverse results for various cytokines as the level of extraction differs noticeably for certain cytokines. A second set of controls (standard curves “with sponges”) should be used to delineate the extent of extraction for each cytokine to be analyzed. Many cytokines/chemokines were detected in tear samples collected with the Merocel sponge, including many that have been implicated in ocular surface disease. Luminex detection of cytokine/chemokine profiles of tears collected with Merocel sponges and extracted with buffer EX1 may be useful in clinical studies, for example, to assess cytokine profiles evaluation in ocular surface diseases. PMID:23233782

Effect of fungal mycelia on the HPLC-UV and UV-vis spectrophotometric assessment of mycelium-bound epoxide hydrolase using glycidyl phenyl ether.

PubMed

Dolcet, Marta M; Torres, Mercè; Canela, Ramon

2016-06-25

The use of mycelia as biocatalysts has technical and economic advantages. However, there are several difficulties in obtaining accurate results in mycelium-catalysed reactions. Firstly, sample extraction, indispensable because of the presence of mycelia, can bring into the extract components with a similar structure to that of the analyte of interest; secondly, mycelia can influence the recovery of the analyte. We prepared calibration standards of 3-phenoxy-1,2-propanediol (PPD) in the pure solvent and in the presence of mycelia (spiked before or after extraction) from five fungi (Aspergillus niger, Aspergillus tubingensis, Penicillium aurantiogriseum, Penicillium sp. and Aspergillus terreus). The quantification of PPD was carried out by HPLC-UV and UV-vis spectrophotometry. The manuscript shows that the last method is as accurate as the HPLC method. However, the colorimetric method led to a higher data throughput, which allowed the study of more samples in a shorter time. Matrix effects were evaluated visually from the plotted calibration data and statistically by simultaneously comparing the intercept and slope of calibration curves performed with solvent, post-extraction spiked standards and pre-extraction spiked standards. Significant differences were found between the post- and pre-extraction spiked matrix-matched functions. Pre-extraction spiked matrix-matched functions based on A. tubingensis mycelia, selected as the reference, were validated and used to compensate for low recoveries. These validated functions were successfully applied to the quantification of PPD achieved during the hydrolysis of glycidyl phenyl ether by mycelium-bound epoxide hydrolases and equivalent hydrolysis yields were determined by HPLC-UV and UV-vis spectrophotometry. This study may serve as starting point to implement matrix effects evaluation when mycelium-bound epoxide hydrolases are studied. Copyright © 2016 Elsevier B.V. All rights reserved.

Development of a selective and pH-independent method for the analysis of ultra trace amounts of nitrite in environmental water samples after dispersive magnetic solid phase extraction by spectrofluorimetry.

PubMed

Daneshvar Tarigh, Ghazale; Shemirani, Farzaneh

2014-10-01

This paper describes an innovative and rapidly dispersive magnetic solid phase extraction spectrofluorimetry (DMSPE-FL) method for the analysis of trace amounts of nitrite in some environmental water samples. The method includes derivatization of aqueous nitrite with 2, 3-diaminonaphthalene (DAN), analysis of highly fluorescent 2, 3-naphthotriazole (NAT) derivative using spectrofluorimetry after DSPME. The novelty of our method is based on forming NAT that was independent with the pH-responsive and was adsorbed on MMWCNT by hydrophobic attractions in both acidic and basic media. The extraction efficiency of the sorbent was investigated by extraction of nitrite. The optimum extraction conditions for NO2(-) were obtained as of extraction time, 1.5 min; 10mg sorbent from 160 mL of the sample solution, and elution with 1 mL of acetone/KOH. Under the optimal conditions, the calibration curves were obtained in the range of 0.1-80 µg L(-1) (R(2)=0.999) and LOD (S/N=3) was obtained in 34 ng L(-1). Relative standard deviations (RSD) were 0.6 % (five replicates at 5 μg L(-1)). In addition, the feasibility of the method was demonstrated with extraction and determination of nitrite from some real samples containing tap, mineral, sea, rain, snow and ground waters, with the recovery in standard addition to real matrix of 94-102 % and RSDs of 1.8-10.6%. Copyright © 2014 Elsevier B.V. All rights reserved.

Evaluation of sequential extraction procedures for soluble and insoluble hexavalent chromium compounds in workplace air samples.

PubMed

Ashley, Kevin; Applegate, Gregory T; Marcy, A Dale; Drake, Pamela L; Pierce, Paul A; Carabin, Nathalie; Demange, Martine

2009-02-01

Because toxicities may differ for Cr(VI) compounds of varying solubility, some countries and organizations have promulgated different occupational exposure limits (OELs) for soluble and insoluble hexavalent chromium (Cr(VI)) compounds, and analytical methods are needed to determine these species in workplace air samples. To address this need, international standard methods ASTM D6832 and ISO 16740 have been published that describe sequential extraction techniques for soluble and insoluble Cr(VI) in samples collected from occupational settings. However, no published performance data were previously available for these Cr(VI) sequential extraction procedures. In this work, the sequential extraction methods outlined in the relevant international standards were investigated. The procedures tested involved the use of either deionized water or an ammonium sulfate/ammonium hydroxide buffer solution to target soluble Cr(VI) species. This was followed by extraction in a sodium carbonate/sodium hydroxide buffer solution to dissolve insoluble Cr(VI) compounds. Three-step sequential extraction with (1) water, (2) sulfate buffer and (3) carbonate buffer was also investigated. Sequential extractions were carried out on spiked samples of soluble, sparingly soluble and insoluble Cr(VI) compounds, and analyses were then generally carried out by using the diphenylcarbazide method. Similar experiments were performed on paint pigment samples and on airborne particulate filter samples collected from stainless steel welding. Potential interferences from soluble and insoluble Cr(III) compounds, as well as from Fe(II), were investigated. Interferences from Cr(III) species were generally absent, while the presence of Fe(II) resulted in low Cr(VI) recoveries. Two-step sequential extraction of spiked samples with (first) either water or sulfate buffer, and then carbonate buffer, yielded quantitative recoveries of soluble Cr(VI) and insoluble Cr(VI), respectively. Three-step sequential extraction gave excessively high recoveries of soluble Cr(VI), low recoveries of sparingly soluble Cr(VI), and quantitative recoveries of insoluble Cr(VI). Experiments on paint pigment samples using two-step extraction with water and carbonate buffer yielded varying percentages of relative fractions of soluble and insoluble Cr(VI). Sequential extractions of stainless steel welding fume air filter samples demonstrated the predominance of soluble Cr(VI) compounds in such samples. The performance data obtained in this work support the Cr(VI) sequential extraction procedures described in the international standards.

Automated prediction of protein function and detection of functional sites from structure.

PubMed

Pazos, Florencio; Sternberg, Michael J E

2004-10-12

Current structural genomics projects are yielding structures for proteins whose functions are unknown. Accordingly, there is a pressing requirement for computational methods for function prediction. Here we present PHUNCTIONER, an automatic method for structure-based function prediction using automatically extracted functional sites (residues associated to functions). The method relates proteins with the same function through structural alignments and extracts 3D profiles of conserved residues. Functional features to train the method are extracted from the Gene Ontology (GO) database. The method extracts these features from the entire GO hierarchy and hence is applicable across the whole range of function specificity. 3D profiles associated with 121 GO annotations were extracted. We tested the power of the method both for the prediction of function and for the extraction of functional sites. The success of function prediction by our method was compared with the standard homology-based method. In the zone of low sequence similarity (approximately 15%), our method assigns the correct GO annotation in 90% of the protein structures considered, approximately 20% higher than inheritance of function from the closest homologue.

Airborne environmental endotoxin: a cross-validation of sampling and analysis techniques.

PubMed Central

Walters, M; Milton, D; Larsson, L; Ford, T

1994-01-01

A standard method for measurement of airborne environmental endotoxin was developed and field tested in a fiberglass insulation-manufacturing facility. This method involved sampling with a capillary-pore membrane filter, extraction in buffer using a sonication bath, and analysis by the kinetic-Limulus assay with resistant-parallel-line estimation (KLARE). Cross-validation of the extraction and assay method was performed by comparison with methanolysis of samples followed by 3-hydroxy fatty acid (3-OHFA) analysis by gas chromatography-mass spectrometry. Direct methanolysis of filter samples and methanolysis of buffer extracts of the filters yielded similar 3-OHFA content (P = 0.72); the average difference was 2.1%. Analysis of buffer extracts for endotoxin content by the KLARE method and by gas chromatography-mass spectrometry for 3-OHFA content produced similar results (P = 0.23); the average difference was 0.88%. The source of endotoxin was gram-negative bacteria growing in recycled washwater used to clean the insulation-manufacturing equipment. The endotoxin and bacteria become airborne during spray cleaning operations. The types of 3-OHFAs in bacteria cultured from the washwater, present in the washwater and in the air, were similar. Virtually all of the bacteria cultured from air and water were gram negative composed mostly of two species, Deleya aesta and Acinetobacter johnsonii. Airborne countable bacteria correlated well with endotoxin (r2 = 0.64). Replicate sampling showed that results with the standard sampling, extraction, and Limulus assay by the KLARE method were highly reproducible (95% confidence interval for endotoxin measurement +/- 0.28 log10). These results demonstrate the accuracy, precision, and sensitivity of the standard procedure proposed for airborne environmental endotoxin. PMID:8161191

Caryocar brasiliense supercritical CO2 extract possesses antimicrobial and antioxidant properties useful for personal care products

PubMed Central

2014-01-01

Background The cosmetic and pharmaceutical industries have an increasing interest in replacing synthetic antimicrobials in dermatological products due to increased microbial resistance to conventional antimicrobial agents. Pequi (Caryocar brasiliense) is a native fruit tree of the Brazilian Cerrado, specifically used in cosmetics, in the food industry, and for medicinal purposes. Leishmanicidal and antifungal activities have been reported previously. This study was designed to evaluate the antimicrobial and antioxidant activities of a C. brasiliense extract obtained by supercritical CO2 extraction. Methods The minimum inhibitory concentrations (MICs) against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus were determined by the classical microdilution method. Antiseptic activity against these organisms was evaluated by the plate diffusion method. The antioxidant potential of the extract was evaluated using a method based on the oxidation of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS). The extract’s chemical profile was analyzed for the presence of alkaloids, saponins, anthraquinones, steroids, tannins, flavonoids, and phenolic compounds according to standard colorimetric methods. Results The C. brasiliense supercritical CO2 extract exhibits antimicrobial activity against all bacteria tested. It also possesses antioxidant activity, when compared to a vitamin E standard. Conclusions The C. brasiliense supercritical CO2 extract may be useful for the development of personal care products, primarily for antiseptic skin products that inactivate, reduce, prevent, or arrest the growth of microorganisms with the inherent intent to mitigate or prevent disease as well as products that minimize damage caused by free radicals. PMID:24565304

Steam distillation/drop-by-drop extraction with gas chromatography-mass spectrometry for fast determination of volatile components in jujube (Ziziphus jujuba Mill.) extract.

PubMed

Sun, Shi-Hao; Chai, Guo-Bi; Li, Peng; Xie, Jian-Ping; Su, Yue

2017-10-13

Jujube extract is commonly used as a food additive and flavoring. The unique jujube aroma and the mild sweet aroma of the extract are critical factors that determine product quality and affect consumer acceptability. The aroma changes with changes in the extraction condition, which is typically dependent on the characteristics of volatile oils in the extract. Despite their importance, the volatile oils of jujube extract have received less attention compared with the soluble components. So, an appropriate qualitative and quantitative method for determination of the volatile oils is vitally important for quality control of the product. A method coupling steam distillation/drop-by-drop extraction with gas chromatography-mass spectrometry (S3DE/GC-MS) was developed to determine the volatile components of jujube extract. Steam distillation was coupled with solvent extraction; the resulting condensate containing volatile components from jujube extract was drop-by-drop extracted using 2 mL of methyl tertiary butyl ether. The solvent served two purposes. First, the solvent extracted the volatile components from the condensate. Second, the volatile components were pre-concentrated by drop-by-drop accumulation in the solvent. As a result, the extraction, separation, and concentration of analytes in the sample were simultaneously completed in one step. The main parameters affecting the S3DE procedure, such as the water steam bubbling rate, extraction solvent volume, sample weight and S3DE time, were optimized. The standard addition approach was essential to obtain accurate measurements by minimizing matrix effects. Good linearity (R 2  ≥ 0.9887) and good repeatability (RSDs ≤ 10.35%, n = 5) for 16 analytes in spiked standard analyte samples were achieved. With the S3DE/GC-MS method, seventy-six volatile compounds from jujube extract were identified and the content of 16 compounds was measured. The results were similar to those from simultaneous distillation extraction. The developed method was simple, fast, effective, sensitive, and provided an overall profile of the volatile components in jujube extract. Thus, this method can be used to determine the volatile components of extracts. Graphical abstract The diagram of steam distillation/drop-by-drop extraction device.

Ketosteroid Standardized Cissus quadrangularis L. Extract and its Anabolic Activity: Time to Look Beyond Ketosteroid?

PubMed

Jadhav, Atul N; Rafiq, Mohammed; Devanathan, Rajendran; Azeemuddin, Mohammed; Anturlikar, Suryakanth D; Ahmed, Akhil; Sundaram, Ramchandran; Babu, U V; Paramesh, Rangesh

2016-05-01

Cissus quadrangularis (CQ) L. reported to contain 3-ketosteroids and have bone health benefits. This study aimed at establishing the relationship between the ketosteroid content and anabolic as well as bone health-promoting activities of various Cissus extracts in well-established orchidectomized (ORX) rat model. Supercritical carbon dioxide, ethyl acetate, and aqueous extracts (AE) of CQ L. were prepared and standardized for ketosteroid content by two methods used in commerce. Moreover, ketosteroid standardized extracts of this plant were evaluated for anabolic activity in rats in well-established ORX rat model. The increase in the absolute weight was appreciable in the CQ-AE treated group. Similarly, with respect to bone parameters, a similar trend was seen. The mean bone density, strength, and calcium content were found to be highest in the group treated with CQ-AE compared to groups treated with other extracts. This study reveals for the first time that 3-ketosteroids are not linked to the beneficial activities on bone and highlights the need for extensive characterization of biological active principles from CQ L. In light of the above estimation studies, we believe that current standardization of Cissus extraction "3-ketosteroids" is incorrect. We also did not find any report suggesting the presence of androgenic steroids in this plant and hence the characterization based on "3-ketosteroids" is scientifically incorrect. This study highlights the insufficient understanding of biological active principles from CQ L. and underlines the need for extensive bioactivity guided studies. Cissus quadrangularis (CQ) L. reported to contain 3.ketosteroids and have bone health benefitsWe did not find correlation between ketosteroid content obtained by conventional methods and its biological effectStudies indicate that claims of ketosteroid content need not necessarily correlate to biological effects and hence warrants extensive phytochemical characterization of biological active principles from CQ L. Abbreviations used: CQ: Cissus quadrangularis, ORX: Orchidectomized, AE: Aqueous extract, EE: Ethyl acetate extract, SFE: Supercritical fluid extract.

Quantitation of acrylamide in food products by liquid chromatography/mass spectrometry.

PubMed

Eberhart, B Loye; Ewald, Deborah K; Sanders, Robert A; Tallmadge, Daniel H; Zyzak, David V; Strothers, Melissa A

2005-01-01

A simple and inexpensive liquid chromatography/mass spectrometry (LC/MS) method was developed for the quantitation of acrylamide in various food products. The method involved spiking the isotope-substituted internal standard (1-C13 acrylamide) onto 6.00 g of the food product, adding 40 mL distilled/deionized water, and heating at 65 degrees C for 30 min. Afterwards, 10 mL ethylene dichloride was added and the mixture was homogenized for 30 s and centrifuged at 2700 x g for 30 min, and then 8 g supernatant was extracted with 10, 5, and 5 mL portions of ethyl acetate. The extracts were combined, dried with sodium sulfate, and concentrated to 100-200 microL. Acrylamide was determined by analysis of the final extract on a single quadrupole, bench-top mass spectrometer with electrospray ionization, using a 2 mm id C18 column and monitoring m/z = 72 (acrylamide) and m/z = 73 (internal standard). For difficult food matrixes, such as coffee and cocoa, a solid-phase extraction cleanup step was incorporated to improve both chromatography and column lifetime. The method had a limit of quantitation of 10 ppb, and coefficients of determination (r2) for calibration curves were typically better than 0.998. Acceptable spike recovery results were achieved in 11 different food matrixes. Precision in potato chip analyses was 5-8% (relative standard deviation). This method provides an LC/MS alternative to the current LC/MS/MS methods and derivatization gas chromatography/mass spectrometry methods, and is applicable to difficult food products such as coffee, cocoa, and high-salt foods.

Optimizing Standard Sequential Extraction Protocol With Lake And Ocean Sediments

EPA Science Inventory

The environmental mobility/availability behavior of radionuclides in soils and sediments depends on their speciation. Experiments have been carried out to develop a simple but robust radionuclide sequential extraction method for identification of radionuclide partitioning in sed...

Long-term variability in sugarcane bagasse feedstock compositional methods: Sources and magnitude of analytical variability

DOE PAGES

Templeton, David W.; Sluiter, Justin B.; Sluiter, Amie; ...

2016-10-18

In an effort to find economical, carbon-neutral transportation fuels, biomass feedstock compositional analysis methods are used to monitor, compare, and improve biofuel conversion processes. These methods are empirical, and the analytical variability seen in the feedstock compositional data propagates into variability in the conversion yields, component balances, mass balances, and ultimately the minimum ethanol selling price (MESP). We report the average composition and standard deviations of 119 individually extracted National Institute of Standards and Technology (NIST) bagasse [Reference Material (RM) 8491] run by seven analysts over 7 years. Two additional datasets, using bulk-extracted bagasse (containing 58 and 291 replicates each),more » were examined to separate out the effects of batch, analyst, sugar recovery standard calculation method, and extractions from the total analytical variability seen in the individually extracted dataset. We believe this is the world's largest NIST bagasse compositional analysis dataset and it provides unique insight into the long-term analytical variability. Understanding the long-term variability of the feedstock analysis will help determine the minimum difference that can be detected in yield, mass balance, and efficiency calculations. The long-term data show consistent bagasse component values through time and by different analysts. This suggests that the standard compositional analysis methods were performed consistently and that the bagasse RM itself remained unchanged during this time period. The long-term variability seen here is generally higher than short-term variabilities. It is worth noting that the effect of short-term or long-term feedstock compositional variability on MESP is small, about $0.03 per gallon. The long-term analysis variabilities reported here are plausible minimum values for these methods, though not necessarily average or expected variabilities. We must emphasize the importance of training and good analytical procedures needed to generate this data. As a result, when combined with a robust QA/QC oversight protocol, these empirical methods can be relied upon to generate high-quality data over a long period of time.« less

Long-term variability in sugarcane bagasse feedstock compositional methods: Sources and magnitude of analytical variability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Templeton, David W.; Sluiter, Justin B.; Sluiter, Amie

In an effort to find economical, carbon-neutral transportation fuels, biomass feedstock compositional analysis methods are used to monitor, compare, and improve biofuel conversion processes. These methods are empirical, and the analytical variability seen in the feedstock compositional data propagates into variability in the conversion yields, component balances, mass balances, and ultimately the minimum ethanol selling price (MESP). We report the average composition and standard deviations of 119 individually extracted National Institute of Standards and Technology (NIST) bagasse [Reference Material (RM) 8491] run by seven analysts over 7 years. Two additional datasets, using bulk-extracted bagasse (containing 58 and 291 replicates each),more » were examined to separate out the effects of batch, analyst, sugar recovery standard calculation method, and extractions from the total analytical variability seen in the individually extracted dataset. We believe this is the world's largest NIST bagasse compositional analysis dataset and it provides unique insight into the long-term analytical variability. Understanding the long-term variability of the feedstock analysis will help determine the minimum difference that can be detected in yield, mass balance, and efficiency calculations. The long-term data show consistent bagasse component values through time and by different analysts. This suggests that the standard compositional analysis methods were performed consistently and that the bagasse RM itself remained unchanged during this time period. The long-term variability seen here is generally higher than short-term variabilities. It is worth noting that the effect of short-term or long-term feedstock compositional variability on MESP is small, about $0.03 per gallon. The long-term analysis variabilities reported here are plausible minimum values for these methods, though not necessarily average or expected variabilities. We must emphasize the importance of training and good analytical procedures needed to generate this data. As a result, when combined with a robust QA/QC oversight protocol, these empirical methods can be relied upon to generate high-quality data over a long period of time.« less

Pressurized liquid extraction and microwave-assisted extraction in the determination of organochlorine pesticides in fish muscle samples.

PubMed

Barriada-Pereira, Mercedes; Iglesias-García, Iván; González-Castro, María J; Muniategui-Lorenzo, Soledad; López-Mahía, Purificación; Prada-Rodríguez, Darío

2008-01-01

This paper describes a comparative study of 2 extraction methods, pressurized liquid extraction (PLE) and microwave-assisted extraction (MAE), for the determination of organochlorine pesticides (OCPs) in fish muscle samples. In both cases, samples were extracted with hexane-acetone (50 + 50), and the extracts were purified by solid-phase extraction using a carbon cartridge as the adsorbent. Pesticides were eluted with hexane-ethyl acetate (80 + 20) and determined by gas chromatography with electron-capture detection. Both methods demonstrated good linearity over the range studied (0.005-0.100 microg/mL). Detection limits ranged from 0.029 to 0.295 mg/kg for PLE and from 0.003 to 0.054 mg/kg for MAE. For most of the pesticides, analytical recoveries with both methods were between 80 and 120%, and the relative standard deviations were < 10%. The proposed methods were shown to be powerful techniques for the extraction of OCPs from fish muscle samples. Although good recovery rates were obtained with both extraction methods, MAE provided advantages with regard to sample handling, cost, analysis time, and solvent consumption. Acceptable validation parameters were obtained although MAE was shown to be more sensitive than PLE.

Extraction and quantitative analysis of iodine in solid and solution matrixes.

PubMed

Brown, Christopher F; Geiszler, Keith N; Vickerman, Tanya S

2005-11-01

129I is a contaminant of interest in the vadose zone and groundwater at numerous federal and privately owned facilities. Several techniques have been utilized to extract iodine from solid matrixes; however, all of them rely on two fundamental approaches: liquid extraction or chemical/heat-facilitated volatilization. While these methods are typically chosen for their ease of implementation, they do not totally dissolve the solid. We defined a method that produces complete solid dissolution and conducted laboratory tests to assess its efficacy to extract iodine from solid matrixes. Testing consisted of potassium nitrate/potassium hydroxide fusion of the sample, followed by sample dissolution in a mixture of sulfuric acid and sodium bisulfite. The fusion extraction method resulted in complete sample dissolution of all solid matrixes tested. Quantitative analysis of 127I and 129I via inductively coupled plasma mass spectrometry showed better than +/-10% accuracy for certified reference standards, with the linear operating range extending more than 3 orders of magnitude (0.005-5 microg/L). Extraction and analysis of four replicates of standard reference material containing 5 microg/g 127I resulted in an average recovery of 98% with a relative deviation of 6%. This simple and cost-effective technique can be applied to solid samples of varying matrixes with little or no adaptation.

Improvement of seawater salt quality by hydro-extraction and re-crystallization methods

NASA Astrophysics Data System (ADS)

Sumada, K.; Dewati, R.; Suprihatin

2018-01-01

Indonesia is one of the salt producing countries that use sea water as a source of raw materials, the quality of salt produced is influenced by the quality of sea water. The resulting average salt quality contains 85-90% NaCl. The Indonesian National Standard (SNI) for human salt’s consumption sodium chloride content is 94.7 % (dry base) and for industrial salt 98,5 %. In this study developed the re-crystallization without chemical and hydro-extraction method. The objective of this research to choose the best methods based on efficiency. The results showed that re-crystallization method can produce salt with NaCl content 99,21%, while hydro-extraction method content 99,34 % NaCl. The salt produced through both methods can be used as a consumption and industrial salt, Hydro-extraction method is more efficient than re-crystallization method because re-crystallization method requires heat energy.

[Study on quality standards of decoction pieces of salt Alpinia].

PubMed

Li, Wenbing; Hu, Changjiang; Long, Lanyan; Huang, Qinwan; Xie, Xiuqiong

2010-12-01

To establish the quality criteria for decoction pieces of salt Alpinia. Decoction pieces of salt Alpinia were measured with moisture, total ash, acid-insoluble ash, water-extract and volatile oils according to the procedures recorded in the Chinese Pharmacopoeia 2010. The content of Nootkatone was determined by HPLC, and NaCl, by chloridion electrode method. We obtained results of total ash, acid-insoluble ash, water-extract and volatile oils of 10 batches of decoction pieces of salt Alpinia moisture; Meanwhile we set the HPLC and chloridion electrode method. This research established a fine quality standard for decoction pieces of salt Alpinia.

Determination of phthalic acid esters in water samples by hollow fiber liquid-phase microextraction prior to gas chromatography tandem mass spectrometry.

PubMed

González-Sálamo, Javier; González-Curbelo, Miguel Ángel; Socas-Rodríguez, Bárbara; Hernández-Borges, Javier; Rodríguez-Delgado, Miguel Ángel

2018-06-01

A new hollow fiber liquid-phase microextraction (HF-LPME) method has been developed for the extraction of a group of phthalic acid esters (PAEs) of interest from different water samples prior to gas chromatography tandem mass spectrometry analysis. HF-LPME was carried out using 1-octanol as extraction solvent followed by a back extraction step with cyclohexane. The different parameters that affect HF-LPME such as sample pH, ionic strength, extraction time, stirring rate, extraction temperature and back extraction conditions were investigated. The optimized conditions involved the extraction of 10 mL of sample without pH adjustment or addition of salt during 75 min under a stirring of 850 rpm at 60 °C and subsequent desorption with 200 μL of cyclohexane for 10 min in an ultrasonic bath. The method was validated in terms of calibration and recovery studies using dibutyl phthalate-d 4 as internal standard. The developed procedure gave satisfactory recovery (74-120%) and relative standard deviation values (<20%) for the studied PAEs in mineral, tap, pond and waste water samples. Copyright © 2018 Elsevier Ltd. All rights reserved.

Improved sample treatment for the determination of insoluble soap in sewage sludge samples by liquid chromatography with fluorescence detection.

PubMed

Cantarero, Samuel; Zafra-Gómez, A; Ballesteros, O; Navalón, A; Vílchez, J L; Crovetto, G; Verge, C; de Ferrer, J A

2010-09-15

A new selective and sensitive method for the determination of insoluble fatty acid salts (soap) in sewage sludge samples is proposed. The method involves a clean up of sample with petroleum ether, the conversion of calcium and magnesium insoluble salts into soluble potassium salts, potassium salts extraction with methanol, and a derivatization procedure previous to the liquid chromatography with fluorescence detection (LC-FLD) analysis. Three different extraction techniques (Soxhlet, microwave-assisted extraction and ultrasounds) were compared and microwave-assisted extraction (MAE) was selected as appropriate for our purpose. This allowed to reduce the extraction time and solvent waste (50 mL of methanol in contrast with 250 mL for Soxhlet procedure). The absence of matrix effect was demonstrated with two standards (C(13:0) and C(17:0)) that are not commercials and neither of them has been detected in sewage sludge samples. Therefore, it was possible to evaluate the matrix effect since both standards have similar environmental behaviour (adsorption and precipitation) to commercial soaps (C(10:0)-C(18:0)). The method was successfully applied to samples from different sources and consequently, with different composition. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Flow injection spectrophotometry using natural reagent from Morinda citrifolia root for determination of aluminium in tea.

PubMed

Tontrong, Sopa; Khonyoung, Supada; Jakmunee, Jaroon

2012-05-01

A flow injection (FI) spectrophotometric method with using natural reagent extracted from Morinda citrifolia root has been developed for determination of aluminium. The extract contained anthraquinone compounds which could react with Al(3+) to form reddish complexes which had maximum absorption wavelength at 499.0nm. The extract could be used as a reagent in FI system without further purification to obtain pure compound. A sensitive method for determination of aluminium in concentration range of 0.1-1.0mgL(-1), with detection limit of 0.05mgL(-1) was achieved. Relative standard deviations of 1.2% and 1.7% were obtained for the determination of 0.1 and 0.6mgL(-1) Al(3+) (n=11). Sample throughput of 35h(-1) was achieved with the consumption of 3mL each of carrier and reagent solutions per injection. The developed method was successfully applied to tea samples, validated by the FAAS standard method. The method is simple, fast, economical and could be classified as a greener analytical method. Copyright © 2011 Elsevier Ltd. All rights reserved.

Pressurized hot water extraction followed by miniaturized membrane assisted solvent extraction for the green analysis of alkylphenols in sediments.

PubMed

Salgueiro-González, N; Turnes-Carou, I; Muniategui-Lorenzo, S; López-Mahía, P; Prada-Rodríguez, D

2015-02-27

A novel and Green analytical methodology for the determination of alkylphenols (4-tert-octylphenol, 4-n-octylphenol, 4-n-nonylphenol, nonylphenol) in sediments was developed and validated. The method was based on pressurized hot water extraction (PHWE) followed by miniaturized membrane assisted solvent extraction (MASE) and liquid chromatography-electrospray ionization tandem mass spectrometry detection (LC-ESI-MS/MS). The extraction conditions were optimized by a Plackett-Burman design in order to minimize the number of assays according to Green principles. Matrix effect was studied and compensated using deuterated labeled standards as surrogate standards for the quantitation of the target compounds. The analytical features of the method were satisfactory: relative recoveries varied between 92 and 103% and repeatability and intermediate precision were <9% for all compounds. Quantitation limits of the method (MQL) ranged from 0.061 (4-n-nonylphenol) to 1.7ngg(-1) dry weight (nonylphenol). Sensitivity, selectivity, automaticity and fastness are the main advantages of the exposed methodology. Reagent consumption, analysis time and waste generation were minimized. The "greenness" of the proposed method was evaluated using an analytical Eco-Scale approach and satisfactory results were obtained. The applicability of the proposed method was demonstrated analysing sediment samples of Galicia coast (NW of Spain) and the ubiquity of alkylphenols in the environment was demonstrated. Copyright © 2015 Elsevier B.V. All rights reserved.

Wavelet images and Chou's pseudo amino acid composition for protein classification.

PubMed

Nanni, Loris; Brahnam, Sheryl; Lumini, Alessandra

2012-08-01

The last decade has seen an explosion in the collection of protein data. To actualize the potential offered by this wealth of data, it is important to develop machine systems capable of classifying and extracting features from proteins. Reliable machine systems for protein classification offer many benefits, including the promise of finding novel drugs and vaccines. In developing our system, we analyze and compare several feature extraction methods used in protein classification that are based on the calculation of texture descriptors starting from a wavelet representation of the protein. We then feed these texture-based representations of the protein into an Adaboost ensemble of neural network or a support vector machine classifier. In addition, we perform experiments that combine our feature extraction methods with a standard method that is based on the Chou's pseudo amino acid composition. Using several datasets, we show that our best approach outperforms standard methods. The Matlab code of the proposed protein descriptors is available at http://bias.csr.unibo.it/nanni/wave.rar .

Extraction method based on emulsion breaking for the determination of Cu, Fe and Pb in Brazilian automotive gasoline samples by high-resolution continuum source flame atomic absorption spectrometry

NASA Astrophysics Data System (ADS)

Leite, Clarice C.; de Jesus, Alexandre; Kolling, Leandro; Ferrão, Marco F.; Samios, Dimitrios; Silva, Márcia M.

2018-04-01

This work reports a new method for extraction of Cu, Fe and Pb from Brazilian automotive gasoline and their determination by high-resolution continuous source flame atomic absorption spectrometry (HR-CS FAAS). The method was based on the formation of water-in-oil emulsion by mixing 2.0 mL of extraction solution constituted by 12% (w/v) Triton X-100 and 5% (v/v) HNO3 with 10 mL of sample. After heating at 90 °C for 10 min, two well-defined phases were formed. The bottom phase (approximately 3.5 mL), composed of acidified water and part of the ethanol originally present in the gasoline sample, containing the extracted analytes was analyzed. The surfactant and HNO3 concentrations and the heating temperature employed in the process were optimized by Doehlert design, using a Brazilian gasoline sample spiked with Cu, Fe and Pb (organometallic compounds). The efficiency of extraction was investigated and it ranged from 80 to 89%. The calibration was accomplished by using matrix matching method. For this, the standards were obtained performing the same extraction procedure used for the sample, using emulsions obtained with a gasoline sample free of analytes and the addition of inorganic standards. Limits of detection obtained were 3.0, 5.0 and 14.0 μg L-1 for Cu, Fe and Pb, respectively. These limits were estimated for the original sample taking into account the preconcentration factor obtained. The accuracy of the proposed method was assured by recovery tests spiking the samples with organometallic standards and the obtained values ranged from 98 to 105%. Ten gasoline samples were analyzed and Fe was found in four samples (0.04-0.35 mg L-1) while Cu (0.28 mg L-1) and Pb (0.60 mg L-1) was found in just one sample.

Quantitative assessment of tumour extraction from dermoscopy images and evaluation of computer-based extraction methods for an automatic melanoma diagnostic system.

PubMed

Iyatomi, Hitoshi; Oka, Hiroshi; Saito, Masataka; Miyake, Ayako; Kimoto, Masayuki; Yamagami, Jun; Kobayashi, Seiichiro; Tanikawa, Akiko; Hagiwara, Masafumi; Ogawa, Koichi; Argenziano, Giuseppe; Soyer, H Peter; Tanaka, Masaru

2006-04-01

The aims of this study were to provide a quantitative assessment of the tumour area extracted by dermatologists and to evaluate computer-based methods from dermoscopy images for refining a computer-based melanoma diagnostic system. Dermoscopic images of 188 Clark naevi, 56 Reed naevi and 75 melanomas were examined. Five dermatologists manually drew the border of each lesion with a tablet computer. The inter-observer variability was evaluated and the standard tumour area (STA) for each dermoscopy image was defined. Manual extractions by 10 non-medical individuals and by two computer-based methods were evaluated with STA-based assessment criteria: precision and recall. Our new computer-based method introduced the region-growing approach in order to yield results close to those obtained by dermatologists. The effectiveness of our extraction method with regard to diagnostic accuracy was evaluated. Two linear classifiers were built using the results of conventional and new computer-based tumour area extraction methods. The final diagnostic accuracy was evaluated by drawing the receiver operating curve (ROC) of each classifier, and the area under each ROC was evaluated. The standard deviations of the tumour area extracted by five dermatologists and 10 non-medical individuals were 8.9% and 10.7%, respectively. After assessment of the extraction results by dermatologists, the STA was defined as the area that was selected by more than two dermatologists. Dermatologists selected the melanoma area with statistically smaller divergence than that of Clark naevus or Reed naevus (P = 0.05). By contrast, non-medical individuals did not show this difference. Our new computer-based extraction algorithm showed superior performance (precision, 94.1%; recall, 95.3%) to the conventional thresholding method (precision, 99.5%; recall, 87.6%). These results indicate that our new algorithm extracted a tumour area close to that obtained by dermatologists and, in particular, the border part of the tumour was adequately extracted. With this refinement, the area under the ROC increased from 0.795 to 0.875 and the diagnostic accuracy showed an increase of approximately 20% in specificity when the sensitivity was 80%. It can be concluded that our computer-based tumour extraction algorithm extracted almost the same area as that obtained by dermatologists and provided improved computer-based diagnostic accuracy.

Study on Quality Standard of Processed Curcuma Longa Radix

PubMed Central

Zhao, Yongfeng; Quan, Liang; Zhou, Haiting; Cao, Dong; Li, Wenbing; Yang, Zhuo

2017-01-01

To control the quality of Curcuma Longa Radix by establishing quality standards, this paper increased the contents of extract and volatile oil determination. Meanwhile, the curcumin was selected as the internal marker, and the relative correlation factors (RCFs) of demethoxycurcumin and bisdemethoxycurcumin were established by high performance liquid chromatography (HPLC). The contents of multicomponents were calculated based on their RCFs. The rationality and feasibility of the methods were evaluated by comparison of the quantitative results between external standard method (ESM) and quantitative analysis of multicomponents by single-marker (QAMS). Ethanol extracts ranged from 9.749 to 15.644% and the mean value was 13.473%. The volatile oil ranged from 0.45 to 0.90 mL/100 g and the mean value was 0.66 mL/100 g. This method was accurate and feasible and could provide a reference for further comprehensive and effective control of the quality standard of Curcuma Longa Radix and its processed products. PMID:29375640

CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING DUST AND SOIL SAMPLES FOR ANALYSIS OF POLAR PERSISTENT ORGANIC POLLUTANTS (SOP-5.15)

EPA Science Inventory

The method for extracting and preparing a dust or soil sample for analysis of polar persistent organic pollutants is summarized in this SOP. It covers the extraction, concentration, and derivatization of samples that are to be analyzed by gas chromatography/mass spectrometry.

CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING URINE SAMPLES FOR ANALYSIS OF HYDROXY POLYCYCLIC AROMATIC HYDROCARBONS, PENTACHLOROPHENOL AND 2,4-D (SOP-5.21)

EPA Science Inventory

The method for extracting and preparing urine samples for analysis of hydroxy-polycyclic aromatic hydrocarbons, pentachlorophenol and 2,4-D is summarized in this SOP. It covers the extraction, concentration and methylation of samples that are to be analyzed by gas chromatography/...

CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING AIR SAMPLES FOR ANALYSIS OF NEUTRAL PERSISTENT ORGANIC POLLUTANTS (SOP-5.12)

EPA Science Inventory

The method is for extracting an indoor and outdoor air sample consisting of a quartz fiber filter and an XAD-2 cartridge for analysis of neutral persistent organic pollutants. It covers the extraction and concentration of samples that are to be analyzed by gas chromatography/mass...

CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING SURFACE WIPE FOR ANALYSIS OF NEUTRAL PERSISTENT ORGANIC POLLUTANTS (SOP-5.17)

EPA Science Inventory

This SOP summarizes the method for extracting and preparing a hard floor surface wipe or food preparation surface wipe sample for analysis of neutral persistent organic. It covers the extraction and concentration of samples that are to be analyzed by gas chromatography/mass spect...

Online induction heating for determination of isotope composition of woody stem water with laser spectrometry: A methods assessment

USGS Publications Warehouse

Lazarus, Brynne E.; Germino, Matthew; Vander Veen, Jessica L.

2016-01-01

Application of stable isotopes of water to studies of plant–soil interactions often requires a substantial preparatory step of extracting water from samples without fractionating isotopes. Online heating is an emerging approach for this need, but is relatively untested and major questions of how to best deliver standards and assess interference by organics have not been evaluated. We examined these issues in our application of measuring woody stem xylem of sagebrush using a Picarro laser spectrometer with online induction heating. We determined (1) effects of cryogenic compared to induction-heating extraction, (2) effects of delivery of standards on filter media compared to on woody stem sections, and (3) spectral interference from organic compounds for these approaches (and developed a technique to do so). Our results suggest that matching sample and standard media improves accuracy, but that isotopic values differ with the extraction method in ways that are not due to spectral interference from organics.

QUANTITATIVE RADIO-CHEMICAL ANALYSIS-SOLVENT EXTRACTION OF MOLYBDENUM-99

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wish, L.

1961-09-12

A method was developed for the rapid quantitative separation of Mo/sup 99/ from fission product mixtures. It is based on the extraction of Mo into a solution of alpha -benzoin oxime in chloroform. The main contaminants are Zr, Nb, and 1. The first two are eliminated by couple with fluoride and the third by volatilization or solvent extraction. About 5% of the Te/sup 99/ daughter is extracted with its parent, and it is necessary to wait 48 hrs for equilibrium of fission product mixtures by this method and a standard radiochemical gravimetric procedure showed agreement within 1 to 2%. (auth)

40 CFR 440.34 - New source performance standards (NSPS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... underground, that produce uranium ore, excluding mines using in situ leach methods, shall not exceed: Effluent... leach process for the extraction of uranium or from mines and mills using in situ leach methods. The... Vanadium Ores Subcategory § 440.34 New source performance standards (NSPS). Except as provided in subpart L...

40 CFR 440.34 - New source performance standards (NSPS).

Code of Federal Regulations, 2012 CFR

2012-07-01

... underground, that produce uranium ore, excluding mines using in situ leach methods, shall not exceed: Effluent... leach process for the extraction of uranium or from mines and mills using in situ leach methods. The... Vanadium Ores Subcategory § 440.34 New source performance standards (NSPS). Except as provided in subpart L...

40 CFR 440.34 - New source performance standards (NSPS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... underground, that produce uranium ore, excluding mines using in situ leach methods, shall not exceed: Effluent... leach process for the extraction of uranium or from mines and mills using in situ leach methods. The... Vanadium Ores Subcategory § 440.34 New source performance standards (NSPS). Except as provided in subpart L...

Analysis of vitamin K1 in fruits and vegetables using accelerated solvent extraction and liquid chromatography tandem mass spectrometry with atmospheric pressure chemical ionization.

PubMed

Jäpelt, Rie Bak; Jakobsen, Jette

2016-02-01

The objective of this study was to develop a rapid, sensitive, and specific analytical method to study vitamin K1 in fruits and vegetables. Accelerated solvent extraction and solid phase extraction was used for sample preparation. Quantification was done by liquid chromatography tandem mass spectrometry with atmospheric pressure chemical ionization in selected reaction monitoring mode with deuterium-labeled vitamin K1 as an internal standard. The precision was estimated as the pooled estimate of three replicates performed on three different days for spinach, peas, apples, banana, and beetroot. The repeatability was 5.2% and the internal reproducibility was 6.2%. Recovery was in the range 90-120%. No significant difference was observed between the results obtained by the present method and by a method using the same principle as the CEN-standard i.e. liquid-liquid extraction and post-column zinc reduction with fluorescence detection. Limit of quantification was estimated to 0.05 μg/100g fresh weight. Copyright © 2015 Elsevier Ltd. All rights reserved.

Simultaneous determination of 29 pharmaceuticals in fish muscle and plasma by ultrasonic extraction followed by SPE-UHPLC-MS/MS.

PubMed

Liu, You-Yu; Hu, Xia-Lin; Bao, Yi-Fan; Yin, Da-Qiang

2018-02-12

A confirmatory method for the simultaneous detection of 29 pharmaceuticals in fish muscle and plasma was developed by using solid-phase extraction combined with ultra high performance liquid chromatography and tandem mass spectrometry. Fish samples were extracted with methanol and enriched using Oasis HLB solid-phase extraction columns in one step. Twenty-nine target pharmaceuticals were quantified by the internal standard method and the calibration curves showed good linearity in a wide range with determination coefficients of greater than 0.913. The detection limits of the pharmaceuticals ranged from 0.01 to 2.00 μg/kg (μg/L). The applicability of the method was checked by precision and recovery experiments. The average recoveries of the 29 pharmaceuticals were between 61 and 111%, and all the relative standard deviations were below 25%. Our reported method has been demonstrated to be sensitive, convenient, rapid and reliable for the simultaneous determination of 29 pharmaceuticals in fish muscle and plasma. Real sample determination showed that 25 and 9 of the 29 compounds were detected in fish muscle and plasma, respectively. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Chemical investigation of commercial grape seed derived products to assess quality and detect adulteration.

PubMed

Villani, Tom S; Reichert, William; Ferruzzi, Mario G; Pasinetti, Giulio M; Simon, James E; Wu, Qingli

2015-03-01

Fundamental concerns in quality control arise due to increasing use of grape seed extract (GSE) and the complex chemical composition of GSE. Proanthocyanidin monomers and oligomers are the major bioactive compounds in GSE. Given no standardized criteria for quality, large variation exists in the composition of commercial GSE supplements. Using HPLC/UV/MS, 21 commercial GSE containing products were purchased and chemically profiled, major compounds quantitated, and compared against authenticated grape seed extract, peanut skin extract, and pine bark extract. The antioxidant capacity and total polyphenol content for each sample was also determined and compared using standard techniques. Nine products were adulterated, found to contain peanut skin extract. A wide degree of variability in chemical composition was detected in commercial products, demonstrating the need for development of quality control standards for GSE. A TLC method was developed to allow for rapid and inexpensive detection of adulteration in GSE by peanut skin. Copyright © 2014 Elsevier Ltd. All rights reserved.

New fluorescence spectroscopic method for the simultaneous determination of alkaloids in aqueous extract of green coffee beans.

PubMed

Yisak, Hagos; Redi-Abshiro, Mesfin; Chandravanshi, Bhagwan Singh

2018-05-11

There is no fluorescence spectroscopic method for the determination of trigonelline and theobromine in green coffee beans. Therefore, the objective of this study was to develop a new fluorescence spectroscopic method to determine the alkaloids simultaneously in the aqueous extract of green coffee beans. The calibration curves were linear in the range 2-6, 1-6, 1-5 mg/L for caffeine, theobromine and trigonelline, respectively, with R 2  ≥ 0.9987. The limit of detection and limit of quantification were 2, 6 and 7 µg/L and 40, 20 and 20 µg/L for caffeine, theobromine and trigonelline, respectively. Caffeine and trigonelline exhibited well separated fluorescence excitation spectra and therefore the two alkaloids were selectively quantified in the aqueous extract of green coffee. While theobromine showed overlapping fluorescence excitation spectra with caffeine and hence theobromine could not be determined in the aqueous extract of green coffee beans. The amount of caffeine and trigonelline in the three samples of green coffee beans were found to be 0.95-1.10 and 1.00-1.10% (w/w), respectively. The relative standard deviations (RSD ≤ 4%) of the method for the three compounds of interest were of very good. The accuracy of the developed analytical method was evaluated by spiking standard caffeine and trigonelline to green coffee beans and the average recoveries were 99 ± 2% for both the alkaloids. A fast, sensitive and reliable fluorescence method for the simultaneous determination of caffeine and trigonelline in the aqueous extract of green coffee beans was developed and validated. The developed method reflected an effective performance to the direct determination of the two alkaloids in the aqueous extract of green coffee beans.

Improving patient safety through a clinical audit spiral: prevention of wrong tooth extraction in orthodontics.

PubMed

Anwar, H; Waring, D

2017-07-07

Introduction With an increasing demand to improve patient safety within the NHS, it is important to ensure that measures are undertaken to continually improve patient care. Wrong site surgery has been defined as a 'never event'. This article highlights the importance of preventing wrong tooth extraction within orthodontics through an audit spiral over five years investigating the accuracy and clarity of orthodontic extraction letters at the University Dental Hospital of Manchester.Aims To examine compliance with the standards for accuracy and clarity of extraction letters and the incidence of wrong tooth extractions, and to increase awareness of the errors that can occur with extraction letters and of the current guidelines.Method A retrospective audit was conducted examining extraction letters sent to clinicians outside the department.Results It can be seen there has been no occurrence of a wrong site tooth extraction. The initial audit highlighted issues in conformity, with it falling below expected standards. Cycle two generally demonstrated a further reduction in compliance. Cycle three appeared to result in an increase in levels of compliance. Cycles 4 and 5 have demonstrated gradual improvements. However, it is noteworthy that in all cycles the audit standards were still not achieved, with the exception of no incidences of the incorrect tooth being extracted.Conclusion This audit spiral demonstrates the importance of long term re-audit to aim to achieve excellence in clinical care. There has been a gradual increase in standards through each audit.

Comparison of methods for determination of total oil sands-derived naphthenic acids in water samples.

PubMed

Hughes, Sarah A; Huang, Rongfu; Mahaffey, Ashley; Chelme-Ayala, Pamela; Klamerth, Nikolaus; Meshref, Mohamed N A; Ibrahim, Mohamed D; Brown, Christine; Peru, Kerry M; Headley, John V; Gamal El-Din, Mohamed

2017-11-01

There are several established methods for the determination of naphthenic acids (NAs) in waters associated with oil sands mining operations. Due to their highly complex nature, measured concentration and composition of NAs vary depending on the method used. This study compared different common sample preparation techniques, analytical instrument methods, and analytical standards to measure NAs in groundwater and process water samples collected from an active oil sands operation. In general, the high- and ultrahigh-resolution methods, namely high performance liquid chromatography time-of-flight mass spectrometry (UPLC-TOF-MS) and Orbitrap mass spectrometry (Orbitrap-MS), were within an order of magnitude of the Fourier transform infrared spectroscopy (FTIR) methods. The gas chromatography mass spectrometry (GC-MS) methods consistently had the highest NA concentrations and greatest standard error. Total NAs concentration was not statistically different between sample preparation of solid phase extraction and liquid-liquid extraction. Calibration standards influenced quantitation results. This work provided a comprehensive understanding of the inherent differences in the various techniques available to measure NAs and hence the potential differences in measured amounts of NAs in samples. Results from this study will contribute to the analytical method standardization for NA analysis in oil sands related water samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparison of ophthalmic sponges and extraction buffers for quantifying cytokine profiles in tears using Luminex technology.

PubMed

Inic-Kanada, Aleksandra; Nussbaumer, Andrea; Montanaro, Jacqueline; Belij, Sandra; Schlacher, Simone; Stein, Elisabeth; Bintner, Nora; Merio, Margarethe; Zlabinger, Gerhard J; Barisani-Asenbauer, Talin

2012-01-01

Evaluating cytokine profiles in tears could shed light on the pathogenesis of various ocular surface diseases. When collecting tears with the methods currently available, it is often not possible to avoid the tear reflex, which may give a different cytokine profile compared to basal tears. More importantly, tear collection with glass capillaries, the most widely used method for taking samples and the best method for avoiding tear reflex, is impractical for remote area field studies because it is tedious and time-consuming for health workers, who cannot collect tears from a large number of patients with this method in one day. Furthermore, this method is uncomfortable for anxious patients and children. Thus, tears are frequently collected using ophthalmic sponges. These sponges have the advantage that they are well tolerated by the patient, especially children, and enable standardization of the tear collection volume. The aim of this study was to compare various ophthalmic sponges and extraction buffers to optimize the tear collection method for field studies for subsequent quantification of cytokines in tears using the Luminex technology. Three ophthalmic sponges, Merocel, Pro-ophta, and Weck-Cel, were tested. Sponges were presoaked with 25 cytokines/chemokines of known concentrations and eluted with seven different extraction buffers (EX1-EX7). To assess possible interference in the assay from the sponges, two standard curves were prepared in parallel: 1) cytokines of known concentrations with the extraction buffers and 2) cytokines of known concentrations loaded onto the sponges with the extraction buffers. Subsequently, a clinical assessment of the chosen sponge-buffer combination was performed with tears collected from four healthy subjects using 1) aspiration and 2) sponges. To quantify cytokine/chemokine recovery and the concentration in the tears, a 25-plex Cytokine Panel and the Luminex xMap were used. This platform enables simultaneous measurement of proinflammatory cytokines, Th1/Th2 distinguishing cytokines, nonspecific acting cytokines, and chemokines. WE DEMONSTRATED THE FOLLOWING: (i) 25 cytokines/chemokines expressed highly variable interactions with buffers and matrices. Several buffers enabled recovery of similar cytokine values (regulated and normal T cell expressed and secreted [RANTES], interleukin [IL]-13, IL-6, IL-8, IL-2R, and granulocyte-macrophage colony-stimulating factor [GM-CSF]); others were highly variable (monocyte chemotactic protein-1 [MCP-1], monokine induced by interferon-gamma [MIG], IL-1β, IL-4, IL-7, and eotaxin). (ii) Various extraction buffers displayed significantly different recovery rates on the same sponge for the same cytokine/chemokine. (iii) The highest recovery rates were obtained with the Merocel ophthalmic sponge except for tumor necrosis factor-α: the Weck-Cel ophthalmic sponge showed the best results, either with cytokine standards loaded onto sponges or with tears collected from the inner canthus of the eye, using the sponge. (iv) IL-5, IL-10, and interferon-α were not detected in any tear sample from four normal human subjects. Twenty-two cytokines/chemokines that we detected were extracted from the Merocel sponge to a satisfactory recovery percentage. The recovery of IL-7 was significantly lower in the extracted Merocel sponge compared to the diluted tear samples. The cytokine/chemokine extraction from tears showed the same pattern of extraction that we observed for extracting the standards. Simultaneous measurement of various cytokines using ophthalmic sponges yielded diverse results for various cytokines as the level of extraction differs noticeably for certain cytokines. A second set of controls (standard curves "with sponges") should be used to delineate the extent of extraction for each cytokine to be analyzed. Many cytokines/chemokines were detected in tear samples collected with the Merocel sponge, including many that have been implicated in ocular surface disease. Luminex detection of cytokine/chemokine profiles of tears collected with Merocel sponges and extracted with buffer EX1 may be useful in clinical studies, for example, to assess cytokine profiles evaluation in ocular surface diseases.

[Determination of 21 fragrance allergens in toys by gas chromatography-ion trap mass spectrometry].

PubMed

Lü, Qing; Zang, Qing; Bai, Hua; Li, Haiyu; Kang, Suyuan; Wang, Chao

2012-05-01

A method of gas chromatography-ion trap mass spectrometry (GC-IT-MS) was developed for the determination of 21 fragrance allergens in sticker toys, plush toys and plastic toys. The experimental conditions, such as sample pretreatment conditions, and the analytical conditions of GC-IT-MS, were optimized. The sticker toy samples and plush toy samples were extracted with acetone by ultrasonic wave, and the extracts were separated on an Agilent HP-1 MS column (50 m x 0.2 mm x 0.5 microm), then determined by IT-MS and quantified by external standard method. The plastic toy samples were extracted by the dissolution-precipitation approach, cleaned up with an Envi-carb solid phase extraction column and concentrated by rotary evaporation and nitrogen blowing, then determined by GC-IT-MS and quantified by external standard method. The calibration curves showed good linearity in the range of 0.002-50 mg/L with the correlation coefficients greater than 0.996 8. The limits of quantification (LOQ, S/N > 10) were 0.02-40 mg/kg. The average recoveries of the target compounds spiked in the sample at three concentration levels were in the range of 82.2%-110.8% with the relative standard deviations (RSDs) of 0.6%-10.5%. These results show that this method is accurate and sensitive for the qualitative and quantitative determination of the 21 fragrance allergens in the 3 types of toys.

Determination of free sulfites (SO3-2) in dried fruits processed with sulfur dioxide by ion chromatography through anion exchange column and conductivity detection.

PubMed

Liao, Benjamin S; Sram, Jacqueline C; Files, Darin J

2013-01-01

A simple and effective anion ion chromatography (IC) method with anion exchange column and conductivity detector has been developed to determine free sulfites (SO3-2) in dried fruits processed with sulfur dioxide. No oxidation agent, such as hydrogen peroxide, is used to convert sulfites to sulfates for IC analysis. In addition, no stabilizing agent, such as formaldehyde, fructose or EDTA, is required during the sample extraction. This method uses aqueous 0.2 N NaOH as the solvent for standard preparation and sample extraction. The sulfites, either prepared from standard sodium sulfite powder or extracted from food samples, are presumed to be unbound SO3-2 in aqueous 0.2 N NaOH (pH > 13), because the bound sulfites in the sample matrix are released at pH > 10. In this study, sulfites in the standard solutions were stable at room temperature (i.e., 15-25 degrees C) for up to 12 days. The lowest standard of the linear calibration curve is set at 1.59 microg/mL SO3-2 (equivalent to 6.36 microg/g sample with no dilution) for analysis of processed dried fruits that would contain high levels (>1000 microg/g) of sulfites. As a consequence, this method typically requires significant dilution of the sample extract. Samples are prepared with a simple procedure of sample compositing, extraction with aqueous 0.2 N NaOH, centrifugation, dilution as needed, and filtration prior to IC. The sulfites in these sample extracts are stable at room temperature for up to 20 h. Using anion IC, the sulfites are eluted under isocratic conditions with 10 mM aqueous sodium carbonate solution as the mobile phase passing through an anion exchange column. The sulfites are easily separated, with an analysis run time of 18 min, regardless of the dried fruit matrix. Recoveries from samples spiked with sodium sulfites were demonstrated to be between 81 and 105% for five different fruit matrixes (apricot, golden grape, white peach, fig, and mango). Overall, this method is simple to perform and effective for the determination of high levels of sulfites in dried fruits.

Anti-Propionibacterium acnes assay-guided purification of brazilin and preparation of brazilin rich extract from Caesalpinia sappan heartwood.

PubMed

Nirmal, Nilesh Prakash; Panichayupakaranant, Pharkphoom

2014-09-01

Caesalpinia sappan L. (Leguminosae or Fabaceae) heartwood has been used as a coloring agent, with antibacterial activity in food, beverages, cosmetics, and garments. To purify brazilin from C. sappan heartwood and use it as a standard marker for the preparation and standardization of an active constituent-rich extract. Crude ethanol extracts of C. sappan heartwood (CSE) were fractionated to isolate brazilin by an anti-P. acnes assay-guided isolation. Quantitative analysis was performed by HPLC. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were determined by the broth microdilution method. Brazilin isolated from CSE possessed antibacterial activity against P. acnes with MIC and MBC values of 15.6 and 31.2 µg/mL, respectively. Brazilin was, therefore, used as a standard marker for standardization and preparation of a brazilin rich extract (BRE). BRE was prepared from CSE using a simple one-step purification using a macroporous resin column eluted with 35% v/v ethanol. This method increased the brazilin content in the BRE up to 39.9% w/w. The antibacterial activity of the standardized BRE against acne involved bacteria was higher than for the CSE but lower than brazilin. However, for industrial applications, a large-scale one-step preparation of BRE has more advantages than the use of pure brazilin in terms of convenience and a low-cost production process. Therefore, BRE is considered as a potential coloring agent with antibacterial activity which is used for pharmaceutical, cosmetic, and nutraceutical applications.

A comparison of two colorimetric assays, based upon Lowry and Bradford techniques, to estimate total protein in soil extracts.

PubMed

Redmile-Gordon, M A; Armenise, E; White, R P; Hirsch, P R; Goulding, K W T

2013-12-01

Soil extracts usually contain large quantities of dissolved humified organic material, typically reflected by high polyphenolic content. Since polyphenols seriously confound quantification of extracted protein, minimising this interference is important to ensure measurements are representative. Although the Bradford colorimetric assay is used routinely in soil science for rapid quantification protein in soil-extracts, it has several limitations. We therefore investigated an alternative colorimetric technique based on the Lowry assay (frequently used to measure protein and humic substances as distinct pools in microbial biofilms). The accuracies of both the Bradford assay and a modified Lowry microplate method were compared in factorial combination. Protein was quantified in soil-extracts (extracted with citrate), including standard additions of model protein (BSA) and polyphenol (Sigma H1675-2). Using the Lowry microplate assay described, no interfering effects of citrate were detected even with concentrations up to 5 times greater than are typically used to extract soil protein. Moreover, the Bradford assay was found to be highly susceptible to two simultaneous and confounding artefacts: 1) the colour development due to added protein was greatly inhibited by polyphenol concentration, and 2) substantial colour development was caused directly by the polyphenol addition. In contrast, the Lowry method enabled distinction between colour development from protein and non-protein origin, providing a more accurate quantitative analysis. These results suggest that the modified-Lowry method is a more suitable measure of extract protein (defined by standard equivalents) because it is less confounded by the high polyphenolic content which is so typical of soil extracts.

Evaluation of a low-cost commercially available extraction device for assessing lead bioaccessibility in contaminated soils.

PubMed

Nelson, Clay M; Gilmore, Thomas M; Harrington, M; Scheckel, Kirk G; Miller, Bradley W; Bradham, Karen D

2013-03-01

The U.S. EPA's in vitro bioaccessibility (IVBA) method 9200.1-86 defines a validated analytical procedure for the determination of lead bioaccessibility in contaminated soils. The method requires the use of a custom-fabricated extraction device that uses a heated water bath for sample incubation. In an effort to improve ease of use, increase sample throughput, and reduce equipment acquisition and maintenance costs, an alternative low-cost, commercially available extraction device capable of sample incubation via heated air and end-over-end rotation was evaluated. An intra-laboratory study was conducted to compare lead bioaccessibility values derived using the two extraction devices. IVBA values were not statistically different (α = 0.05) between the two extraction devices for any of the soils (n = 6) evaluated in this study, with an average difference in mean lead IVBA of 0.8% (s.d. = 0.5%). The commercially available extraction device was able to generate accurate lead IVBA data as compared to the U.S. EPA's expected value for a National Institute of Standards and Technology standard reference material soil. The relative percent differences between high and low IVBA values for each soil, a measure of instrument precision, were also not statistically different (α = 0.05) between the two extraction devices. The statistical agreement of lead IVBA values observed using the two extraction devices supports the use of a low-cost, commercially available extraction device as a reliable alternative to a custom-fabricated device as required by EPA method 9200.1-86.

A single extraction and HPLC procedure for simultaneous analysis of phytosterols, tocopherols and lutein in soybeans.

PubMed

Slavin, Margaret; Yu, Liangli Lucy

2012-12-15

A saponification/extraction procedure and high performance liquid chromatography (HPLC) analysis method were developed and validated for simultaneous analysis of phytosterols, tocopherols and lutein (a carotenoid) in soybeans. Separation was achieved on a phenyl column with a ternary, isocratic solvent system of acetonitrile, methanol and water (48:22.5:29.5, v/v/v). Evaporative light scattering detection (ELSD) was used to quantify β-sitosterol, stigmasterol, campesterol, and α-, δ- and γ-tocopherols, while lutein was quantified with visible light absorption at 450 nm. Peak identification was verified by retention times and spikes with external standards. Standard curves were constructed (R(2)>0.99) to allow for sample quantification. Recovery of the saponification and extraction was demonstrated via analysis of spiked samples. Also, the accuracy of results of four soybeans using the described saponification and HPLC analytical method was validated against existing methods. This method offers a more efficient alternative to individual methods for quantifying lutein, tocopherols and sterols in soybeans. Copyright © 2012 Elsevier Ltd. All rights reserved.

Isolation of atropine and scopolamine from plant material using liquid-liquid extraction and EXtrelut® columns.

PubMed

Śramska, Paula; Maciejka, Artur; Topolewska, Anna; Stepnowski, Piotr; Haliński, Łukasz P

2017-02-01

Tropane alkaloids are toxic secondary metabolites produced by Solanaceae plants. Among them, plants from Datura genus produce significant amounts of scopolamine and hyoscyamine; the latter undergoes racemization to atropine during isolation. Because of their biological importance, toxic properties and commonly reported food and animal feed contamination by different Datura sp. organs, there is a constant need for reliable methods for the analysis of tropane alkaloids in many matrices. In the current study, three extraction and sample-clean up procedures for the determination of scopolamine and atropine in plant material were compared in terms of their effectiveness and repeatability. Standard liquid-liquid extraction (LLE) and EXtrelut ® NT 3 columns were used for the sample clean-up. Combined ultrasound-assisted extraction and 24h static extraction using ethyl acetate, followed by multiple LLE steps was found the most effective separation method among tested. However, absolute extraction recovery was relatively low and reached 45-67% for atropine and 52-73% for scopolamine, depending on the compound concentration. The same method was also the most effective one for the isolation of target compounds from Datura stramonium leaves. EXtrelut ® columns, on the other hand, displayed relatively low effectiveness in isolating atropine and scopolamine from such a complex matrix and hence could not be recommended. The most effective method was also applied to the extraction of alkaloids from roots and stems of D. stramonium. Quantitative analyses were performed using validated method based on gas chromatography with flame ionization detector (GC-FID). Based on the results, the importance of the proper selection of internal standards in the analysis of tropane alkaloids was stressed out. Copyright © 2016 Elsevier B.V. All rights reserved.

Application of standard addition for the determination of carboxypeptidase activity in Actinomucor elegans bran koji.

PubMed

Fu, J; Li, L; Yang, X Q; Zhu, M J

2011-01-01

Leucine carboxypeptidase (EC 3.4.16) activity in Actinomucor elegans bran koji was investigated via absorbance at 507 nm after stained by Cd-nihydrin solution, with calibration curve A, which was made by a set of known concentration standard leucine, calibration B, which was made by three sets of known concentration standard leucine solutions with the addition of three concentrations inactive crude enzyme extract, and calibration C, which was made by three sets of known concentration standard leucine solutions with the addition of three concentrations crude enzyme extract. The results indicated that application of pure amino acid standard curve was not a suitable way to determine carboxypeptidase in complicate mixture, and it probably led to overestimated carboxypeptidase activity. It was found that addition of crude exact into pure amino acid standard curve had a significant difference from pure amino acid standard curve method (p < 0.05). There was no significant enzyme activity difference (p > 0.05) between addition of active crude exact and addition of inactive crude kind, when the proper dilute multiple was used. It was concluded that the addition of crude enzyme extract to the calibration was needed to eliminate the interference of free amino acids and related compounds presented in crude enzyme extract.

Sensitive diagnosis of cutaneous leishmaniasis by lesion swab sampling coupled to qPCR

PubMed Central

ADAMS, EMILY R.; GOMEZ, MARIA ADELAIDA; SCHESKE, LAURA; RIOS, RUBY; MARQUEZ, RICARDO; COSSIO, ALEXANDRA; ALBERTINI, AUDREY; SCHALLIG, HENK; SARAVIA, NANCY GORE

2015-01-01

SUMMARY Variation in clinical accuracy of molecular diagnostic methods for cutaneous leishmaniasis (CL) is commonly observed depending on the sample source, the method of DNA recovery and the molecular test. Few attempts have been made to compare these variables. Two swab and aspirate samples from lesions of patients with suspected CL (n = 105) were evaluated alongside standard diagnosis by microscopic detection of amastigotes or culture of parasites from lesion material. Three DNA extraction methods were compared: Qiagen on swab and aspirate specimens, Isohelix on swabs and Boil/Spin of lesion aspirates. Recovery of Leishmania DNA was evaluated for each sample type by real-time polymerase chain reaction detection of parasitic 18S rDNA, and the diagnostic accuracy of the molecular method determined. Swab sampling combined with Qiagen DNA extraction was the most efficient recovery method for Leishmania DNA, and was the most sensitive (98%; 95% CI: 91–100%) and specific (84%; 95% CI: 64–95%) approach. Aspirated material was less sensitive at 80% (95% CI: 70–88%) and 61% (95% CI: 50–72%) when coupled to Qiagen or Boil-Spin DNA extraction, respectively. Swab sampling of lesions was painless, simple to perform and coupled with standardized DNA extraction enhances the feasibility of molecular diagnosis of CL. PMID:25111885

Simultaneous determination of 117 pesticides and 30 mycotoxins in raw coffee, without clean-up, by LC-ESI-MS/MS analysis.

PubMed

Reichert, Bárbara; de Kok, André; Pizzutti, Ionara Regina; Scholten, Jos; Cardoso, Carmem Dickow; Spanjer, Martien

2018-04-03

This paper describes the optimization and validation of an acetonitrile based method for simultaneous extraction of multiple pesticides and mycotoxins from raw coffee beans followed by LC-ESI-MS/MS determination. Before extraction, the raw coffee samples were milled and then slurried with water. The slurried samples were spiked with two separate standard solutions, one containing 131 pesticides and a second with 35 mycotoxins, which were divided into 3 groups of different relative concentration levels. Optimization of the QuEChERS approach included performance tests with acetonitrile acidified with acetic acid or formic acid, with or without buffer and with or without clean-up of the extracts before LC-ESI-MS/MS analysis. For the clean-up step, seven d-SPE sorbents and their various mixtures were evaluated. After method optimization a complete validation study was carried out to ensure adequate performance of the extraction and chromatographic methods. The samples were spiked at 3 concentrations levels with both mycotoxins and pesticides (with 6 replicates at each level, n = 6) and then submitted to the extraction procedure. Before LC-ESI-MS/MS analysis, the acetonitrile extracts were diluted 2-fold with methanol, in order to improve the chromatographic performance of the early-eluting polar analytes. Calibration standard solutions were prepared in organic solvent and in blank coffee extract at 7 concentration levels and analyzed 6 times each. The method was assessed for accuracy (recovery %), precision (RSD%), selectivity, linearity (r 2 ), limit of quantification (LOQ) and matrix effects (%). Copyright © 2017 Elsevier B.V. All rights reserved.

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of methylene blue active substances by spectrophotometry

USGS Publications Warehouse

Burkhardt, Mark R.; Cinotto, Pete J.; Frahm, Galen W.; Woodworth, Mark T.; Pritt, Jeffrey W.

1995-01-01

A method for the determination of methylene blue active substances in whole-water samples by liquid-liquid extraction and spectrophotometric detection is described. Sulfate and sulfonate-based surfectants are reacted with methylene blue to form a blue-colored complex. The complex is extracted into chloroform, back-washed with an acidified phosphate-based buffer solution, and measured against external standards with a probe spectrophotometer. The method detection limt for routine analysis is 0.02 milligram per liter. The precision is plus/minus 10 percent relative standard deviation. The positive bias from nitrate and chloride and U.S. Geological Survey method O-3111-83 for methylene blue active substances is minized by adding a back-washing step.

[Solubilization Specificities Interferon beta-1b from Inclusion Bodies].

PubMed

Zhuravko, A S; Kononova, N V; Bobruskin, A I

2015-01-01

A new solubilization method of recombinant interferon beta-1b (IFNβ-1b) from the inclusion bodies was developed. This method allows to extract the target protein selectively in the solutions of different alcohols, such as ethanol, propanol and isopropanol. It was shown that the more effective IFNβ-1b solubilization was achieved in the 55% propanol solution. This method allowed to extract the target protein from inclusion bodies around 85-90%, and significantly reduced Escherichia coli content in the solubilizate, in comparison with standard methods.

Rapid mixed mode solid phase extraction method for the determination of acrylamide in roasted coffee by HPLC-MS/MS.

PubMed

Bortolomeazzi, Renzo; Munari, Marina; Anese, Monica; Verardo, Giancarlo

2012-12-15

In this work, a rapid and reliable purification method based on a single mixed solid phase extraction (SPE) column, for the determination of acrylamide in roasted coffee by liquid chromatography-tandem mass spectrometry, was developed. Deuterium labelled d(3)-acrylamide was used as internal standard. Acrylamide was extracted by 10 mL of water and the extract purified by a single SPE column consisting of 0.5 g of an in-house prepared mixture of C18, strong cation (SCX) and anion exchange (SAX) sorbents in the ratio 2/1.5/1.5 (w/w/w). The amount of the three sorbents was optimised in order to eliminate the main interfering compounds present in coffee extracts, such as melanoidins, trigonelline, chlorogenic acids and caffeine. The SPE procedure was very simple and consisted of pushing 1 mL of an aqueous coffee extract through the SPE column followed by 1 mL of water which was collected for the analysis. The method was tested on six samples of roasted coffee of different composition and roasting level. The repeatability of the method, expressed as relative standard deviation (n=6), was lower than 5%. The recovery of acrylamide at three spiked levels ranged from 92% to 95%. The limits of detection (LOD) and quantitation (LOQ) were 5 and 16 μg kg(-1), respectively. Copyright © 2012 Elsevier Ltd. All rights reserved.

[Determination of eight pesticide residues in tea by liquid chromatography-tandem mass spectrometry and its uncertainty evaluation].

PubMed

Hu, Beizhen; Cai, Haijiang; Song, Weihua

2012-09-01

A method was developed for the determination of eight pesticide residues (fipronil, imidacloprid, acetamiprid, buprofezin, triadimefon, triadimenol, profenofos, pyridaben) in tea by liquid chromatography-tandem mass spectrometry. The sample was extracted by accelerated solvent extraction with acetone-dichloromethane (1:1, v/v) as solvent, and the extract was then cleaned-up with a Carb/NH2 solid phase extraction (SPE) column. The separation was performed on a Hypersil Gold C, column (150 mm x 2. 1 mm, 5 microm) and with the gradient elution of acetonitrile and 0. 1% formic acid. The eight pesticides were determined in the modes of electrospray ionization (ESI) and multiple reaction monitoring (MRM). The analytes were quantified by matrix-matched internal standard method for imidacloprid and acetamiprid, by matrix-matched external standard method for the other pesticides. The calibration curves showed good linearity in 1 - 100 microg/L for fipronil, and in 5 -200 microg/L for the other pesticides. The limits of quantification (LOQs, S/N> 10) were 2 p.g/kg for fipronil and 10 microg/kg for the other pesticides. The average recoveries ranged from 75. 5% to 115.0% with the relative standard deviations of 2.7% - 7.7% at the spiked levels of 2, 5, 50 microg/kg for fipronil and 10, 50, 100 microg/kg for the other pesticides. The uncertainty evaluation for the results was carried out according to JJF 1059-1999 "Evaluation and Expression of Uncertainty in Measurement". Items constituting measurement uncertainty involved standard solution, weighing of sample, sample pre-treatment, and the measurement repeatability of the equipment were evaluated. The results showed that the measurement uncertainty is mainly due to sample pre-treatment, standard curves and measurement repeatability of the equipment. The method developed is suitable for the conformation and quantification of the pesticides in tea.

Acetonitrile extraction and dual-layer solid phase extraction clean-up for pesticide residue analysis in propolis.

PubMed

Oellig, Claudia

2016-05-06

Propolis is a very complex mixture of substances that is produced by honey bees and is known to be a rather challenging matrix for residue analysis. Besides resins, flavonoids and phenols, high amount of wax is co-extracted resulting in immense matrix effects. Therefore a suitable clean-up is crucial and indispensable. In this study, a reliable solid phase extraction (SPE) clean-up was developed for pesticide residue analysis in propolis. The clean-up success was quickly and easily monitored by high-performance thin-layer chromatography with different detection possibilities. The final method consists of the extraction of propolis with acetonitrile according to the QuEChERS method followed by an effective extract purification on dual-layer SPE cartridges with spherical hydrophobic polystyrene-divinylbenzene resin/primary secondary amine as sorbent and a mixture of toluene/acetone (95:5, v/v) for elution. Besides fat-soluble components like waxes, flavonoids, and terpenoids, more polar compounds like organic acids, fatty acids, sugars and anthocyanins were also removed to large extent. Method performance was assessed by recovery experiments at spiking levels of 0.5 and 1mg/kg (n=5) for fourteen pesticides that are relevant for propolis. Mean recoveries determined by HPLC-MS against solvent standards were between 40 and 101%, while calculation against matrix-matched standards provided recoveries of 79-104%. Precision of recovery, assessed by relative standard deviations, were below 9%. Thus, the developed dual-layer SPE clean-up enables the reliable pesticide residue analysis in propolis and provides a suitable alternative to time-consuming clean-up procedures proposed in literature. Copyright © 2016 Elsevier B.V. All rights reserved.

The Application of a Novel Pressurized Liquid Extraction Method to Quantify Organic Tracers Combined with Historic and Novel Organic Contaminants for the Discover-AQ Houston Field Experiment

NASA Astrophysics Data System (ADS)

Clark, A. E.; Yoon, S.; Sheesley, R. J.; Usenko, S.

2014-12-01

DISCOVER-AQ is a NASA mission seeking to better understand air quality in cities across the United States. In September 2013, flight, satellite and ground-based data was collected in Houston, TX and the surrounding metropolitan area. Over 300 particulate matter filter samples were collected as part of the ground-based sampling efforts, at four sites across Houston. Samples include total suspended particle matter (TSP) and fine particulate matter (less than 2.5 μm in aerodynamic diameter; PM2.5). For this project, an analytical method has been developed for the pressurized liquid extraction (PLE) of a wide variety of organic tracers and contaminants from quartz fiber filters (QFFs). Over 100 compounds were selected including polycyclic aromatic hydrocarbons (PAHs), hopanes, levoglucosan, organochlorine pesticides, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organophosphate flame retardants (OPFRs). Currently, there is no analytical method validated for the reproducible extraction of all seven compound classes in a single automated technique. Prior to extraction, QFF samples were spiked with known amounts of target analyte standards and isotopically-labeled surrogate standards. The QFF were then extracted with methylene chloride:acetone at high temperatures (100˚C) and pressures (1500 psi) using a Thermo Dionex Accelerated Solvent Extractor system (ASE 350). Extracts were concentrated, spiked with known amounts of isotopically-labeled internal standards, and analyzed by gas chromatography coupled with mass spectrometry utilizing electron ionization and electron capture negative ionization. Target analytes were surrogate recovery-corrected to account for analyte loss during sample preparation. Ambient concentrations of over 100 organic tracers and contaminants will be presented for four sites in Houston during DISCOVER-AQ.

[Simultaneous determination of 33 primary aromatic amines in polystyrene and polyethylene masterbatches for foods by ultra-performance liquid chromatography-tandem mass spectrometry

PubMed

Man, Zhengyin; Wang, Quanlin; Li, Hesheng; Zhang, Aizhi; Shen, Jian

2015-03-01

A comprehensive analytical method based on ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC-MS/MS) has been developed for the simultaneous determination of 33 primary aromatic amines (PAAs) in polystyrene (PS) and polyethylene (PE) masterbatches for foods. The PS masterbatches were dissolved with dichloromethane, and methanol was added to precipitate after extraction by ultrasound extraction. Then the extract was purified by passing through a carbon graphite solid phase extraction column. The PE masterbatches were swelled and extracted with dichloromethane by ultrasound. The purified PS solution and PE extract were concentrated, and diluted to 2 mL with methanol-water (1:9, v/v), and filtered through the membranes of 0.22 µm before UPLC-MS/MS analysis. The analytes were separated on a BEH Phenyl column (100 mm x 2.1 mm, 1.7 µm), eluted by gradient with 0.07% (v/v) formic acid in methanol-water (1:9, v/v). The PAAs were detected by UPLC-MS/MS under multiple reaction monitoring (MRM) mode and quantified by the internal standard method. The separation conditions, fragment voltages and collision energies were optimized. The impacts of extraction times, extraction solvents and concentration methods on recoveries were studied. The limits of detection for the 33 primary aromatic amines were 6-10 µg/kg, and the limits of quantitation were 20-30 µg/kg. The mean recoveries of the two different masterbatch products at three spiked levels of 20, 100, 200 µg/kg were 61.3%-119.8%, and the relative standard deviations were 1.4%-14.8%. The experimental results indicated that the method is simple, rapid, sensitive, accurate, and can meet the related requirements for determination.

Extracting organic matter on Mars: A comparison of methods involving subcritical water, surfactant solutions and organic solvents

NASA Astrophysics Data System (ADS)

Luong, Duy; Court, Richard W.; Sims, Mark R.; Cullen, David C.; Sephton, Mark A.

2014-09-01

The first step in many life detection protocols on Mars involves attempts to extract or isolate organic matter from its mineral matrix. A number of extraction options are available and include heat and solvent assisted methods. Recent operations on Mars indicate that heating samples can cause the loss or obfuscation of organic signals from target materials, raising the importance of solvent-based systems for future missions. Several solvent types are available (e.g. organic solvents, surfactant based solvents and subcritical water extraction) but a comparison of their efficiencies in Mars relevant materials is missing. We have spiked the well characterised Mars analogue material JSC Mars-1 with a number of representative organic standards. Extraction of the spiked JSC Mars-1 with the three solvent methods provides insights into the relative efficiency of these methods and indicates how they may be used on future Mars missions.

[Simultaneous determination of delta-9-tetrahydrocannabinol cannabidiol and cannabinol in edible oil using ultra performance liquid chromatography-tandem mass spectrometry].

PubMed

Zhang, Aizhi; Wang, Quanlin; Mo, Shijie

2010-11-01

A method for the simultaneous determination of delta-9-tetrahydrocannabinol (THC), cannabidiol (CBD) and cannabinol (CBN) in edible oil was developed using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The target compounds were extracted with methanol, purified by an LC-Alumina-N solid phase extraction cartridge, separated and detected by the UPLC-MS/MS. Quantitative analysis was corrected by an isotope internal standard method using delta-9-THC-D3 as internal standard. Average recoveries for the target compounds varied from 68.0% to 101.6% with the relative standard deviations ranging from 7.0% to 20.1% at three spiked levels. The limits of detection (LOD) of the method were from 0.06-0.17 microg/kg and the limits of quantification (LOQ) were in the range of 0.20-0.52 microg/kg. The results showed that the method is able to meet the requirements for the simultaneous determination of THC, CBD and CBN in edible oil.

Ultrasonication extraction and gel permeation chromatography clean-up for the determination of polycyclic aromatic hydrocarbons in edible oil by an isotope dilution gas chromatography–mass spectrometry.

PubMed

Wang, Jian-Hua; Guo, Cui

2010-07-09

An analytical method for the determination of US EPA priority pollutant 16 polycyclic aromatic hydrocarbons (PAHs) in edible oil was developed by an isotope dilution gas chromatography-mass spectrometry (GC-MS). Extraction was performed with ultrasonication mode using acetonitrile as solvent, and subsequent clean-up was applied using narrow gel permeation chromatographic column. Three deuterated PAHs surrogate standards were used as internal standards for quantification and analytical quality control. The limits of quantification (LOQs) were globally below 0.5 ng/g, the recoveries were in the range of 81-96%, and the relative standard deviations (RSDs) were lower than 20%. Further trueness assessment of the method was also verified through participation in international cocoa butter proficiency test (T0638) organised by the FAPAS with excellent results in 2008. The results obtained with the described method were satisfying (z ≤ 2). The method has been applied to determine PAH in real edible oil samples.

An HPLC/UV method for the determination of RGH-1756 in dog and rat plasma.

PubMed

Terjéki, E; Kapás, M

2001-03-01

RGH-1756 (1-(2-methoxy-phenyl)-4-(4-[4-(6-imidazo[2,1-b]-thiazolyl)-phenoxy]-butyl)-piperazine dimethansulphonate) is a novel atypical antipsychotic candidate of Gedeon Richter Ltd. A new HPLC method has been developed and validated for the quantitative determination of RGH-1756 in dog and rat plasma. The compound and the internal standard are extracted from the biological samples by a simple and fast liquid--liquid extraction method, using 1-chlorobutane. The recovery for RGH-1756 is about 90%. The extracts are analyzed by reversed phase HPLC (column: Supelcosil-LC-18-DB 250*4.6 mm, 5 microm, eluent:acetonitrile:methanol:0.2 molar ammonium-acetate 40:25:35, lambda=254 nm). The assay is specific for RGH-1756. The standard curves are linear in the range between 10 and 2000 ng ml(-1). The overall precision (expressed as CV%) and accuracy (expressed as bias%) of quality controls and calibration standards are within 15%. The validated lower limit of quantification is 10 ng/ml. No indications have been found for possible instabilities of RGH-1756 in plasma, in the extraction solvent, or after repeated thawing-freezing cycles. The method has been succesfully applied for the bioavailability studies of RGH-1756 in the two animal species. In these studies results of the inprocess method validation have shown the reliability of the method, too. CV% of quality controls in the rat study has been found between 7.4 and 10.0%, in the dog study between 4.1 and 12.5%. The bias has ranged from 0.4 to 3.8% and from -4.5 to 1.2% in the rat and dog study, respectively.

The effect of different conventional methods of extraction on Marantodes pumila var. pumila leaves in relation to free radical scavenging activity

NASA Astrophysics Data System (ADS)

Hamid, Noor Huda Abd; Latip, Jalifah; Markom, Masturah

2018-04-01

Marantodes pumila is one of the important herbs used in traditional medicine. However, there is no report on the optimum method for the preparation of M. pumila extract enriched with bioactive compounds. Therefore, this study aim to establish the suitable method in the preparation of M. pumila extracts enriched with antioxidative compounds. Different conventional extraction methods such as maceration, reflux and Soxhlet in solvents of different polarities i.e. ethanol, 50 % aqueous ethanol and water were employed to prepare extracts. Constituents of each extract were profiled using RP-HPLC followed by the free radical scavenging assay using 2,2 diphenyl-1-picrylhydrazyl (DPPH) to determine the antioxidant activity. Among all extraction methods, maceration in 50 % aqueous ethanol gave the highest total percentage yield (22.41 %) while all extraction methods were able to extract the marker compounds, gallic acid (GA) and methyl gallate (MGA). The free radical scavenging activity of extracts varied from IC50 11.93 µg/mL (50 % aqueous ethanol via reflux) to 64.15 µg/mL (water via maceration). All extracts showed better scavenging activity as compared to synthetic antioxidant, BHT. The variation in the IC50 values is expected due to the presence of different types and/or concentration of bioactive compounds in each extract. This study may provide a preliminary insight for the preparation of standardized extracts of M. pumila enriched with bioactive compounds.

Extracting insights from the shape of complex data using topology

PubMed Central

Lum, P. Y.; Singh, G.; Lehman, A.; Ishkanov, T.; Vejdemo-Johansson, M.; Alagappan, M.; Carlsson, J.; Carlsson, G.

2013-01-01

This paper applies topological methods to study complex high dimensional data sets by extracting shapes (patterns) and obtaining insights about them. Our method combines the best features of existing standard methodologies such as principal component and cluster analyses to provide a geometric representation of complex data sets. Through this hybrid method, we often find subgroups in data sets that traditional methodologies fail to find. Our method also permits the analysis of individual data sets as well as the analysis of relationships between related data sets. We illustrate the use of our method by applying it to three very different kinds of data, namely gene expression from breast tumors, voting data from the United States House of Representatives and player performance data from the NBA, in each case finding stratifications of the data which are more refined than those produced by standard methods. PMID:23393618

Extracting insights from the shape of complex data using topology.

PubMed

Lum, P Y; Singh, G; Lehman, A; Ishkanov, T; Vejdemo-Johansson, M; Alagappan, M; Carlsson, J; Carlsson, G

2013-01-01

This paper applies topological methods to study complex high dimensional data sets by extracting shapes (patterns) and obtaining insights about them. Our method combines the best features of existing standard methodologies such as principal component and cluster analyses to provide a geometric representation of complex data sets. Through this hybrid method, we often find subgroups in data sets that traditional methodologies fail to find. Our method also permits the analysis of individual data sets as well as the analysis of relationships between related data sets. We illustrate the use of our method by applying it to three very different kinds of data, namely gene expression from breast tumors, voting data from the United States House of Representatives and player performance data from the NBA, in each case finding stratifications of the data which are more refined than those produced by standard methods.

Evolution of Quantitative Measures in NMR: Quantum Mechanical qHNMR Advances Chemical Standardization of a Red Clover (Trifolium pratense) Extract

PubMed Central

2017-01-01

Chemical standardization, along with morphological and DNA analysis ensures the authenticity and advances the integrity evaluation of botanical preparations. Achievement of a more comprehensive, metabolomic standardization requires simultaneous quantitation of multiple marker compounds. Employing quantitative 1H NMR (qHNMR), this study determined the total isoflavone content (TIfCo; 34.5–36.5% w/w) via multimarker standardization and assessed the stability of a 10-year-old isoflavone-enriched red clover extract (RCE). Eleven markers (nine isoflavones, two flavonols) were targeted simultaneously, and outcomes were compared with LC-based standardization. Two advanced quantitative measures in qHNMR were applied to derive quantities from complex and/or overlapping resonances: a quantum mechanical (QM) method (QM-qHNMR) that employs 1H iterative full spin analysis, and a non-QM method that uses linear peak fitting algorithms (PF-qHNMR). A 10 min UHPLC-UV method provided auxiliary orthogonal quantitation. This is the first systematic evaluation of QM and non-QM deconvolution as qHNMR quantitation measures. It demonstrates that QM-qHNMR can account successfully for the complexity of 1H NMR spectra of individual analytes and how QM-qHNMR can be built for mixtures such as botanical extracts. The contents of the main bioactive markers were in good agreement with earlier HPLC-UV results, demonstrating the chemical stability of the RCE. QM-qHNMR advances chemical standardization by its inherent QM accuracy and the use of universal calibrants, avoiding the impractical need for identical reference materials. PMID:28067513

1H NMR quantification in very dilute toxin solutions: application to anatoxin-a analysis.

PubMed

Dagnino, Denise; Schripsema, Jan

2005-08-01

A complete procedure is described for the extraction, detection and quantification of anatoxin-a in biological samples. Anatoxin-a is extracted from biomass by a routine acid base extraction. The extract is analysed by GC-MS, without the need of derivatization, with a detection limit of 0.5 ng. A method was developed for the accurate quantification of anatoxin-a in the standard solution to be used for the calibration of the GC analysis. 1H NMR allowed the accurate quantification of microgram quantities of anatoxin-a. The accurate quantification of compounds in standard solutions is rarely discussed, but for compounds like anatoxin-a (toxins with prices in the range of a million dollar a gram), of which generally only milligram quantities or less are available, this factor in the quantitative analysis is certainly not trivial. The method that was developed can easily be adapted for the accurate quantification of other toxins in very dilute solutions.

Antimicrobial and antioxidant effect of methanolic Crinum jagus bulb extract in wound healing

PubMed Central

Udegbunam, Sunday Ositadimma; Udegbunam, Rita Ijeoma; Nnaji, Theophilus Okafor; Anyanwu, Madubuike Umunna; Kene, Raphel Okoli Chukwujekwu; Anika, Silavanus Maduka

2015-01-01

Aim: The aim of this study was to evaluate the antimicrobial and antioxidant effects of Crinum jagus (J. Thomps.) Dandy methanolic bulb extract in wound healing. Materials and Methods: Phytochemical screening revealed the presence of alkaloids, glycosides, tannins, and saponins in the extract. In vitro antimicrobial activity of the extract was determined by agar well diffusion method. In vivo antimicrobial activity of the extract was determined by microbial assay of excision wound in rats contaminated with Staphylococcus aureus, Bacillus subtilis, Pseudomonas areuginosa, and Candida albicans and treated with 300 mg/kg body weight (bw) of 10 and 5% methanolic C. jagus bulb extract ointment (MCJBEO), respectively. Enzymatic antioxidant effect of the extract was determined in vivo by assaying superoxide dismutase (SOD) and catalase (CAT) activity, and malondialdehyde (MDA) level in excision wound biopsies of rats treated with 10 and 5% MCJBEO, respectively, following standard methods. Non-enzymatic antioxidant effect of the extract was determined in vitro using diphenylpicrylhydrazyl (DPPH) method following standard procedure. Results: The extract exhibited in vitro antimicrobial effect in a concentration-dependent manner with one hundred (100) mg/ml concentration of the extract having the highest inhibitory zone diameter for B. subtilis (25 mm), S. aureus (21 mm), and C. albicans (14 mm) followed by the 50, 25 and 12.5 mg/ml concentrations, respectively. B. subtilis, S. aureus, and C. albicans were not isolated from wounds of animals treated with both extract concentrations 10% and 5% MCJBEO, and reference drug (framycetin sulfate/clotrimazole). Activities of the enzymatic antioxidants SOD and CAT in wound biopsies treated with 10% MCJBEO were significantly (P < 0.05) higher when compared with those treated with 5% MCJBEO. Significantly (P < 0.05) decreased MDA level of wound biopsies from extract-treated rats was observed. The extract exhibited non-enzymatic antioxidant (DPPH) effect in a concentration-dependent manner. Conclusion: This study has shown that an anti-microbial and antioxidant effects could possibly be part of mechanism by which C. jagus bulb extract promote wound healing process. PMID:26401415

Report - Antibacterial activity of sea buckthorn (Hippophae rhamnoides L.) against methicillin resistant Staphylococcus aureus (MRSA).

PubMed

Qadir, Muhammad Imran; Abbas, Khizar; Younus, Adnan; Shaikh, Rehan Sadiq

2016-09-01

Objective of the present study was to investigate the antibacterial activity of Sea buckthorn (Hippophae rhamnoides L.) berries and leaves against methicillin resistant Staphylococcus aureus (MRSA) by using the standard disc diffusion method. Chloroform, n-hexane and aqueous extract of the plant parts were used. Doses of 2mg/ml, 4 mg/ml and 6mg/ml were tested against the microorganism, and the zone of inhibition was compared against the standard drug vancomycin. Results indicated that n-hexane and chloroform extracts of berries and n-hexane extract leaves showed significant (p<0.05) antibacterial activity comparable with vancomycin. It was concluded from the study that extracts berries and leaves of Hippophae rhamnoides have antibacterial activity against MRSA.

Development of an extractive spectrophotometric method for estimation of uranium in ore leach solutions using 2-ethylhexyl phosphonic acid-mono-2-ethylhexyl ester (PC88A) and tri-n-octyl phosphine oxide (TOPO) mixture as extractant and 2-(5-bromo-2-pyridylozo)-5-diethyl aminophenol (Br-PADAP) as chromophore.

PubMed

Biswas, Sujoy; Pathak, P N; Roy, S B

2012-06-01

An extractive spectrophotometric analytical method has been developed for the determination of uranium in ore leach solution. This technique is based on the selective extraction of uranium from multielement system using a synergistic mixture of 2-ethylhexyl phosphonic acid-mono-2-ethylhexyl ester (PC88A) and tri-n-octyl phosphine oxide (TOPO) in cyclohexane and color development from the organic phase aliquot using 2-(5-Bromo-2-pyridylazo)-5-diethyl aminophenol (Br-PADAP) as chromogenic reagent. The absorption maximum (λ(max)) for UO(2)(2+)-Br-PADAP complex in organic phase samples, in 64% (v/v) ethanol containing buffer solution (pH 7.8) and 1,2-cyclohexylenedinitrilotetraacetic acid (CyDTA) complexing agent, has been found to be at 576 nm (molar extinction coefficient, ɛ: 36,750 ± 240 L mol(-1)cm(-1)). Effects of various parameters like stability of complex, ethanol volume, ore matrix, interfering ions etc. on the determination of uranium have also been evaluated. Absorbance measurements as a function of time showed that colored complex is stable up to > 24h. Presence of increased amount of ethanol in colored solution suppresses the absorption of a standard UO(2)(2+)-Br-PADAP solution. Analyses of synthetic standard as well as ore leach a solution show that for 10 determination relative standard deviation (RSD) is < 2%. The accuracy of the developed method has been checked by determining uranium using standard addition method and was found to be accurate with a 98-105% recovery rate. The developed method has been applied for the analysis of a number of uranium samples generated from uranium ore leach solutions and results were compared with standard methods like inductively coupled plasma emission spectrometry (ICPAES). The determined values of uranium concentrations by these methods are within ± 2%. This method can be used to determine 2.5-250 μg mL(-1) uranium in ore leach solutions with high accuracy and precision. Copyright © 2012 Elsevier B.V. All rights reserved.

Comparison of various extraction methods for policosanol from rice bran wax and establishment of chromatographic fingerprint of policosanol.

PubMed

Wang, Mei-Fei; Lian, Hong-Zhen; Mao, Li; Zhou, Jing-Ping; Gong, Hui-Juan; Qian, Bao-Yong; Fang, Yan; Li, Jie

2007-07-11

A capillary gas chromatographic (GC) method has been developed for the separation and determination of policosanol components extracted from rice bran wax. A Varian CP-sil 8 CB column was employed, and an oven temperature was programmed. Gas chromatography-mass spectrometry (GC-MS) was used to identify the composition of policosanol. Quantitative analysis was carried out by means of hydrogen flame ionization detector (FID) with dinonyl phthalate (DNP) as internal standard. The results indicated that the extract obtained by dry saponification has the highest contents of octacosanol and triacontanol among extracts by all used extraction methods including dry saponification, saponification in alcohol, saponification in water (neutralized and non-neutralized), and transesterification. Meanwhile, the GC-MS fingerprint of policosanol extracted by dry saponification has been established. Euclidean distance similarity calculation showed remarkable consistency of compositions and contents among 12 batches of policosanol from a rice bran wax variety. This protocol provided a rapid and feasible method for quality control of policosanol products.

The BUME method: a new rapid and simple chloroform-free method for total lipid extraction of animal tissue

NASA Astrophysics Data System (ADS)

Löfgren, Lars; Forsberg, Gun-Britt; Ståhlman, Marcus

2016-06-01

In this study we present a simple and rapid method for tissue lipid extraction. Snap-frozen tissue (15-150 mg) is collected in 2 ml homogenization tubes. 500 μl BUME mixture (butanol:methanol [3:1]) is added and automated homogenization of up to 24 frozen samples at a time in less than 60 seconds is performed, followed by a 5-minute single-phase extraction. After the addition of 500 μl heptane:ethyl acetate (3:1) and 500 μl 1% acetic acid a 5-minute two-phase extraction is performed. Lipids are recovered from the upper phase by automated liquid handling using a standard 96-tip robot. A second two-phase extraction is performed using 500 μl heptane:ethyl acetate (3:1). Validation of the method showed that the extraction recoveries for the investigated lipids, which included sterols, glycerolipids, glycerophospholipids and sphingolipids were similar or better than for the Folch method. We also applied the method for lipid extraction of liver and heart and compared the lipid species profiles with profiles generated after Folch and MTBE extraction. We conclude that the BUME method is superior to the Folch method in terms of simplicity, through-put, automation, solvent consumption, economy, health and environment yet delivering lipid recoveries fully comparable to or better than the Folch method.

Quantification of the predominant monomeric catechins in baking chocolate standard reference material by LC/APCI-MS.

PubMed

Nelson, Bryant C; Sharpless, Katherine E

2003-01-29

Catechins are polyphenolic plant compounds (flavonoids) that may offer significant health benefits to humans. These benefits stem largely from their anticarcinogenic, antioxidant, and antimutagenic properties. Recent epidemiological studies suggest that the consumption of flavonoid-containing foods is associated with reduced risk of cardiovascular disease. Chocolate is a natural cocoa bean-based product that reportedly contains high levels of monomeric, oligomeric, and polymeric catechins. We have applied solid-liquid extraction and liquid chromatography coupled with atmospheric pressure chemical ionization-mass spectrometry to the identification and determination of the predominant monomeric catechins, (+)-catechin and (-)-epicatechin, in a baking chocolate Standard Reference Material (NIST Standard Reference Material 2384). (+)-Catechin and (-)-epicatechin are detected and quantified in chocolate extracts on the basis of selected-ion monitoring of their protonated [M + H](+) molecular ions. Tryptophan methyl ester is used as an internal standard. The developed method has the capacity to accurately quantify as little as 0.1 microg/mL (0.01 mg of catechin/g of chocolate) of either catechin in chocolate extracts, and the method has additionally been used to certify (+)-catechin and (-)-epicatechin levels in the baking chocolate Standard Reference Material. This is the first reported use of liquid chromatography/mass spectrometry for the quantitative determination of monomeric catechins in chocolate and the only report certifying monomeric catechin levels in a food-based Standard Reference Material.

Extraction protocol and liquid chromatography/tandem mass spectrometry method for determining micelle-entrapped paclitaxel at the cellular and subcellular levels: Application to a cellular uptake and distribution study.

PubMed

Zheng, Nan; Lian, Bin; Du, Wenwen; Xu, Guobing; Ji, Jiafu

2018-01-01

Paclitaxel-loaded polymeric micelles (PTX-PM) are commonly used as tumor-targeted nanocarriers and display outstanding antitumor features in clinic, but its accumulation and distribution in vitro are lack of investigation. It is probably due to the complex micellar system and its low concentration at the cellular or subcellular levels. In this study, we developed an improved extraction method, which was a combination of mechanical disruption and liquid-liquid extraction (LLE), to extract the total PTX from micelles in the cell lysate and subcellular compartments. An ultra-performance liquid chromatography tandem mass spectroscopy (UPLC-MS/MS) method was optimized to detect the low concentration of PTX at cellular and subcellular levels simultaneously, using docetaxel as internal standard (IS). The method was proved to release PTX totally from micelles (≥95.93%) with a consistent and reproducible extraction recovery (≥75.04%). Good linearity was obtained at concentrations ranging from 0.2 to 20ng/mL. The relative error (RE%) for accuracy varied from 0.68 to 7.56%, and the intra- and inter-precision (relative standard deviation, RSD%) was less than 8.64% and 13.14%, respectively. This method was fully validated and successfully applied to the cellular uptake and distribution study of PTX-loaded PLGA-PEG micelles in human breast cancer cells (MCF-7). Copyright © 2017 Elsevier B.V. All rights reserved.

7 CFR 51.1179 - Method of juice extraction.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946 FRESH FRUITS, VEGETABLES AND OTHER PRODUCTS 1,2 (INSPECTION, CERTIFICATION, AND...

Development, validation and evaluation of an analytical method for the determination of monomeric and oligomeric procyanidins in apple extracts.

PubMed

Hollands, Wendy J; Voorspoels, Stefan; Jacobs, Griet; Aaby, Kjersti; Meisland, Ane; Garcia-Villalba, Rocio; Tomas-Barberan, Francisco; Piskula, Mariusz K; Mawson, Deborah; Vovk, Irena; Needs, Paul W; Kroon, Paul A

2017-04-28

There is a lack of data for individual oligomeric procyanidins in apples and apple extracts. Our aim was to develop, validate and evaluate an analytical method for the separation, identification and quantification of monomeric and oligomeric flavanols in apple extracts. To achieve this, we prepared two types of flavanol extracts from freeze-dried apples; one was an epicatechin-rich extract containing ∼30% (w/w) monomeric (-)-epicatechin which also contained oligomeric procyanidins (Extract A), the second was an oligomeric procyanidin-rich extract depleted of epicatechin (Extract B). The parameters considered for method optimisation were HPLC columns and conditions, sample heating, mass of extract and dilution volumes. The performance characteristics considered for method validation included standard linearity, method sensitivity, precision and trueness. Eight laboratories participated in the method evaluation. Chromatographic separation of the analytes was best achieved utilizing a Hilic column with a binary mobile phase consisting of acidic acetonitrile and acidic aqueous methanol. The final method showed linearity for epicatechin in the range 5-100μg/mL with a correlation co-efficient >0.999. Intra-day and inter-day precision of the analytes ranged from 2 to 6% and 2 to 13% respectively. Up to dp3, trueness of the method was >95% but decreased with increasing dp. Within laboratory precision showed RSD values <5 and 10% for monomers and oligomers, respectively. Between laboratory precision was 4 and 15% (Extract A) and 7 and 30% (Extract B) for monomers and oligomers, respectively. An analytical method for the separation, identification and quantification of procyanidins in an apple extract was developed, validated and assessed. The results of the inter-laboratory evaluation indicate that the method is reliable and reproducible. Copyright © 2017. Published by Elsevier B.V.

Determination of low levels of perchlorate in lettuce and spinach using ion chromatography-electrospray ionization mass spectrometry (IC-ESI-MS).

PubMed

Seyfferth, Angelia L; Parker, David R

2006-03-22

A sample preparation method was developed to quantify environmentally relevant (low micrograms per liter) concentrations of perchlorate (ClO4(-)) in leafy vegetables using IC-ESI-MS. Lettuce and spinach were macerated, centrifuged, and filtered, and the aqueous extracts were rendered water-clear using a one-step solid-phase extraction method. Total time for extraction and sample preparation was 6 h. Ion suppression was demonstrated and was likely due to unknown organics still present in the extract solution after cleanup. However, this interference was readily eliminated using a Cl(18)O4(-) internal standard at 1 microg/L in all standards and samples. Hydroponically grown perchlorate-free butterhead lettuce was spiked to either 10.3 or 37.7 microg/kg of fresh weight (FW), and recoveries were between 91 and 98% and between 93 and 101%, respectively. Five types of lettuce and spinach from a local grocery store were then analyzed; they contained from 0.6 to 6.4 microg/kg of FW. Spike recoveries using the store-bought samples ranged from 89 to 100%. The method detection limit for perchlorate in plant extracts is 40 ng/L, and the corresponding minimum reporting limit is 200 ng/L or 0.8 microg/kg of FW.

Simple and efficient method for region of interest value extraction from picture archiving and communication system viewer with optical character recognition software and macro program.

PubMed

Lee, Young Han; Park, Eun Hae; Suh, Jin-Suck

2015-01-01

The objectives are: 1) to introduce a simple and efficient method for extracting region of interest (ROI) values from a Picture Archiving and Communication System (PACS) viewer using optical character recognition (OCR) software and a macro program, and 2) to evaluate the accuracy of this method with a PACS workstation. This module was designed to extract the ROI values on the images of the PACS, and created as a development tool by using open-source OCR software and an open-source macro program. The principal processes are as follows: (1) capture a region of the ROI values as a graphic file for OCR, (2) recognize the text from the captured image by OCR software, (3) perform error-correction, (4) extract the values including area, average, standard deviation, max, and min values from the text, (5) reformat the values into temporary strings with tabs, and (6) paste the temporary strings into the spreadsheet. This principal process was repeated for the number of ROIs. The accuracy of this module was evaluated on 1040 recognitions from 280 randomly selected ROIs of the magnetic resonance images. The input times of ROIs were compared between conventional manual method and this extraction module-assisted input method. The module for extracting ROI values operated successfully using the OCR and macro programs. The values of the area, average, standard deviation, maximum, and minimum could be recognized and error-corrected with AutoHotkey-coded module. The average input times using the conventional method and the proposed module-assisted method were 34.97 seconds and 7.87 seconds, respectively. A simple and efficient method for ROI value extraction was developed with open-source OCR and a macro program. Accurate inputs of various numbers from ROIs can be extracted with this module. The proposed module could be applied to the next generation of PACS or existing PACS that have not yet been upgraded. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.

Cloud point extraction of Δ9-tetrahydrocannabinol from cannabis resin.

PubMed

Ameur, S; Haddou, B; Derriche, Z; Canselier, J P; Gourdon, C

2013-04-01

A cloud point extraction coupled with high performance liquid chromatography (HPLC/UV) method was developed for the determination of Δ(9)-tetrahydrocannabinol (THC) in micellar phase. The nonionic surfactant "Dowfax 20B102" was used to extract and pre-concentrate THC from cannabis resin, prior to its determination with a HPLC-UV system (diode array detector) with isocratic elution. The parameters and variables affecting the extraction were investigated. Under optimum conditions (1 wt.% Dowfax 20B102, 1 wt.% Na2SO4, T = 318 K, t = 30 min), this method yielded a quite satisfactory recovery rate (~81 %). The limit of detection was 0.04 μg mL(-1), and the relative standard deviation was less than 2 %. Compared with conventional solid-liquid extraction, this new method avoids the use of volatile organic solvents, therefore is environmentally safer.

A sensitive analytical procedure for monitoring acrylamide in environmental water samples by offline SPE-UPLC/MS/MS.

PubMed

Togola, Anne; Coureau, Charlotte; Guezennec, Anne-Gwenaëlle; Touzé, Solène

2015-05-01

The presence of acrylamide in natural systems is of concern from both environmental and health points of view. We developed an accurate and robust analytical procedure (offline solid phase extraction combined with UPLC/MS/MS) with a limit of quantification (20 ng L(-1)) compatible with toxicity threshold values. The optimized (considering the nature of extraction phases, sampling volumes, and solvent of elution) solid phase extraction (SPE) was validated according to ISO Standard ISO/IEC 17025 on groundwater, surface water, and industrial process water samples. Acrylamide is highly polar, which induces a high variability during the SPE step, therefore requiring the use of C(13)-labeled acrylamide as an internal standard to guarantee the accuracy and robustness of the method (uncertainty about 25 % (k = 2) at limit of quantification level). The specificity of the method and the stability of acrylamide were studied for these environmental media, and it was shown that the method is suitable for measuring acrylamide in environmental studies.

Manipulation of the micro and macro-structure of beams extracted from cyclotrons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laxdal, R.E.

1995-09-01

It is standard practice in cyclotrons to alter the extracted micro-pulse width by using center-region slits and/or by chopping the beam before injection. The macro-structure can also be varied by means of pulsed or sinusoidal deflection devices before injection and/or after extraction. All above methods, however, involve cutting away the unwanted beam, thus reducing the time-averaged intensity. This paper will focus on some methods used to alter the time structure of extracted beams without significant beam loss. For example radial gradients in the accelerating fields from rf cavities can be utilized to compress, expand or even split longitudinally the circulatingmore » particle bunches. The macro-structure of the extracted beam can be altered by employing resonant extraction methods and replacing the static magnetic bump with either a pulsed or a sinusoidal transverse perturbation. The methods are most suitable for H cyclotrons but may also be considered in a limited scope for cyclotrons using direct extraction. Results of computer simulations and beam tests on the TRIUMF 500 MeV H{sup {minus}} cyclotron will be presented.« less

Studies on the antioxidant activities of natural vanilla extract and its constituent compounds through in vitro models.

PubMed

Shyamala, B N; Naidu, M Madhava; Sulochanamma, G; Srinivas, P

2007-09-19

Vanilla extract was prepared by extraction of cured vanilla beans with aqueous ethyl alcohol (60%). The extract was profiled by HPLC, wherein major compounds, viz., vanillic acid, 4-hydroxybenzyl alcohol, 4-hydroxy-3-methoxybenzyl alcohol, 4-hydroxybenzaldehyde and vanillin, could be identified and separated. Extract and pure standard compounds were screened for antioxidant activity using beta-carotene-linoleate and DPPH in vitro model systems. At a concentration of 200 ppm, the extract showed 26% and 43% of antioxidant activity by beta-carotene-linoleate and DPPH methods, respectively, in comparison to corresponding values of 93% and 92% for BHA. Interestingly, 4-hydroxy-3-methoxybenzyl alcohol and 4-hydroxybenzyl alcohol exhibited antioxidant activity of 65% and 45% by beta-carotene-linoleate method and 90% and 50% by DPPH methods, respectively. In contrast, pure vanillin exhibited much lower antioxidant activity. The present study points toward the potential use of vanilla extract components as antioxidants for food preservation and in health supplements as nutraceuticals.

EXTRACT: interactive extraction of environment metadata and term suggestion for metagenomic sample annotation.

PubMed

Pafilis, Evangelos; Buttigieg, Pier Luigi; Ferrell, Barbra; Pereira, Emiliano; Schnetzer, Julia; Arvanitidis, Christos; Jensen, Lars Juhl

2016-01-01

The microbial and molecular ecology research communities have made substantial progress on developing standards for annotating samples with environment metadata. However, sample manual annotation is a highly labor intensive process and requires familiarity with the terminologies used. We have therefore developed an interactive annotation tool, EXTRACT, which helps curators identify and extract standard-compliant terms for annotation of metagenomic records and other samples. Behind its web-based user interface, the system combines published methods for named entity recognition of environment, organism, tissue and disease terms. The evaluators in the BioCreative V Interactive Annotation Task found the system to be intuitive, useful, well documented and sufficiently accurate to be helpful in spotting relevant text passages and extracting organism and environment terms. Comparison of fully manual and text-mining-assisted curation revealed that EXTRACT speeds up annotation by 15-25% and helps curators to detect terms that would otherwise have been missed. Database URL: https://extract.hcmr.gr/. © The Author(s) 2016. Published by Oxford University Press.

Use of an enzyme-assisted method to improve protein extraction from olive leaves.

PubMed

Vergara-Barberán, M; Lerma-García, M J; Herrero-Martínez, J M; Simó-Alfonso, E F

2015-02-15

The improvement of protein extraction from olive leaves using an enzyme-assisted protocol has been investigated. Using a cellulase enzyme (Celluclast® 1.5L), different parameters that affect the extraction process, such as the influence and amount of organic solvent, enzyme amount, pH and extraction temperature and time, were optimised. The influence of these factors was examined using the standard Bradford assay and the extracted proteins were characterised by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The optimum extraction parameters were: 30% acetonitrile, 5% (v/v) Celluclast® 1.5L at pH 5.0 and 55°C for 15min. Under these conditions, several protein extracts from olive leaves of different genetic variety (with a total protein amount comprised between 1.87 and 6.64mgg(-1)) were analysed and compared by SDS-PAGE, showing differences in their electrophoretic protein profiles. The developed enzyme-assisted extraction method has shown a faster extraction, higher recovery and reduced solvent usage with respect to the use of the non-enzymatic methods described in literature. Copyright © 2014 Elsevier Ltd. All rights reserved.

A selective and sensitive method for quantitation of lysergic acid diethylamide (LSD) in whole blood by gas chromatography-ion trap tandem mass spectrometry.

PubMed

Libong, Danielle; Bouchonnet, Stéphane; Ricordel, Ivan

2003-01-01

A gas chromatography-ion trap tandem mass spectrometry (GC-ion trap MS-MS) method for detection and quantitation of LSD in whole blood is presented. The sample preparation process, including a solid-phase extraction step with Bond Elut cartridges, was performed with 2 mL of whole blood. Eight microliters of the purified extract was injected with a cold on-column injection method. Positive chemical ionization was performed using acetonitrile as reagent gas; LSD was detected in the MS-MS mode. The chromatograms obtained from blood extracts showed the great selectivity of the method. GC-MS quantitation was performed using lysergic acid methylpropylamide as the internal standard. The response of the MS was linear for concentrations ranging from 0.02 ng/mL (detection threshold) to 10.0 ng/mL. Several parameters such as the choice of the capillary column, the choice of the internal standard and that of the ionization mode (positive CI vs. EI) were rationalized. Decomposition pathways under both ionization modes were studied. Within-day and between-day stability were evaluated.

7 CFR 51.1179 - Method of juice extraction.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG PRODUCTS INSPECTION ACT FRESH FRUITS, VEGETABLES AND OTHER PRODUCTS 1 2...

7 CFR 51.1179 - Method of juice extraction.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG PRODUCTS INSPECTION ACT FRESH FRUITS, VEGETABLES AND OTHER PRODUCTS 1,2...

Evaluation of antibacterial and anthelmintic activities with total phenolic contents of Piper betel leaves

PubMed Central

Akter, Kazi Nahid; Karmakar, Palash; Das, Abhijit; Anonna, Shamima Nasrin; Shoma, Sharmin Akter; Sattar, Mohammad Mafruhi

2014-01-01

Objective: The study was conducted to investigate the antibacterial and anthelmintic activities and to determine total phenolic contents of methanolic extract of Piper betel leaves. Materials and Methods: The extract was subjected to assay for antibacterial activity using both gram positive and gram negative bacterial strains through disc diffusion method; anthelmintic activity with the determination of paralysis and death time using earthworm (Pheritima posthuma) at five different concentrations and the determination of total phenolic contents using the Folin-ciocalteau method. Results: The extract showed significant (p<0.01) zone of inhibitions against gram positive Staphylococcus aureus [(6.77±0.25) mm] and Gram negative Escherichia coli [(8.53±0.25) mm], Salmonella typhi [(5.20±0.26) mm], Shigella dysenteriae [(11.20±0.26) mm] compared to positive control Azithromycin (ranging from 20.10±0.17 to 25.20±0.35 mm) while no zone inhibitory activity was found for both the extract and the standard drug against Gram positive Bacillus cereus. The extract also showed potent anthelmintic activity requiring less time for paralysis and death compared to the standard drug albendazole (10 mg/ml). At concentrations 10, 20, 40, 60 and 80 mg/ml, leaves extract showed paralysis at mean time of 9.83±0.60, 8.50±0.29, 6.60±0.17, 6.20±0.44 and 4.16±0.60; death at 11.33±0.88, 9.67±0.33, 7.83±0.17, 7.16±0.60 and 5.16±0.72 minutes, respectively. Whereas the standard drug showed paralysis and death at 19.33±0.71 and 51.00±0.23 minutes respectively. The extract confirmed the higher concentration of phenolic contents (124.42±0.14 mg of GAE /g of extract) when screened for total phenolic compounds. Conclusion: As results confirmed potential antibacterial and anthelmintic activities of Piper betel leaves extract, therefore it may be processed for further drug research. PMID:25386394

Rapid and reliable high-throughput methods of DNA extraction for use in barcoding and molecular systematics of mushrooms.

PubMed

Dentinger, Bryn T M; Margaritescu, Simona; Moncalvo, Jean-Marc

2010-07-01

We present two methods for DNA extraction from fresh and dried mushrooms that are adaptable to high-throughput sequencing initiatives, such as DNA barcoding. Our results show that these protocols yield ∼85% sequencing success from recently collected materials. Tests with both recent (<2 year) and older (>100 years) specimens reveal that older collections have low success rates and may be an inefficient resource for populating a barcode database. However, our method of extracting DNA from herbarium samples using small amount of tissue is reliable and could be used for important historical specimens. The application of these protocols greatly reduces time, and therefore cost, of generating DNA sequences from mushrooms and other fungi vs. traditional extraction methods. The efficiency of these methods illustrates that standardization and streamlining of sample processing should be shifted from the laboratory to the field. © 2009 Blackwell Publishing Ltd.

Determination of Wastewater Compounds in Whole Water by Continuous Liquid-Liquid Extraction and Capillary-Column Gas Chromatography/Mass Spectrometry

USGS Publications Warehouse

Zaugg, Steven D.; Smith, Steven G.; Schroeder, Michael P.

2006-01-01

A method for the determination of 69 compounds typically found in domestic and industrial wastewater is described. The method was developed in response to increasing concern over the impact of endocrine-disrupting chemicals on aquatic organisms in wastewater. This method also is useful for evaluating the effects of combined sanitary and storm-sewer overflow on the water quality of urban streams. The method focuses on the determination of compounds that are indicators of wastewater or have endocrine-disrupting potential. These compounds include the alkylphenol ethoxylate nonionic surfactants, food additives, fragrances, antioxidants, flame retardants, plasticizers, industrial solvents, disinfectants, fecal sterols, polycyclic aromatic hydrocarbons, and high-use domestic pesticides. Wastewater compounds in whole-water samples were extracted using continuous liquid-liquid extractors and methylene chloride solvent, and then determined by capillary-column gas chromatography/mass spectrometry. Recoveries in reagent-water samples fortified at 0.5 microgram per liter averaged 72 percent ? 8 percent relative standard deviation. The concentration of 21 compounds is always reported as estimated because method recovery was less than 60 percent, variability was greater than 25 percent relative standard deviation, or standard reference compounds were prepared from technical mixtures. Initial method detection limits averaged 0.18 microgram per liter. Samples were preserved by adding 60 grams of sodium chloride and stored at 4 degrees Celsius. The laboratory established a sample holding-time limit prior to sample extraction of 14 days from the date of collection.

Novel methodology to isolate microplastics from vegetal-rich samples.

PubMed

Herrera, Alicia; Garrido-Amador, Paloma; Martínez, Ico; Samper, María Dolores; López-Martínez, Juan; Gómez, May; Packard, Theodore T

2018-04-01

Microplastics are small plastic particles, globally distributed throughout the oceans. To properly study them, all the methodologies for their sampling, extraction, and measurement should be standardized. For heterogeneous samples containing sediments, animal tissues and zooplankton, several procedures have been described. However, definitive methodologies for samples, rich in algae and plant material, have not yet been developed. The aim of this study was to find the best extraction protocol for vegetal-rich samples by comparing the efficacies of five previously described digestion methods, and a novel density separation method. A protocol using 96% ethanol for density separation was better than the five digestion methods tested, even better than using H 2 O 2 digestion. As it was the most efficient, simple, safe and inexpensive method for isolating microplastics from vegetal rich samples, we recommend it as a standard separation method. Copyright © 2018 Elsevier Ltd. All rights reserved.

Liquid-liquid and solid-phase extractions of phenols from virgin olive oil and their separation by chromatographic and electrophoretic methods.

PubMed

Bendini, Alessandra; Bonoli, Matteo; Cerretani, Lorenzo; Biguzzi, Barbara; Lercker, Giovanni; Toschi, Tullia Gallina

2003-01-24

The high oxidative stability of virgin olive oil is related to its high monounsaturated/polyunsaturated ratio and to the presence of antioxidant compounds, such as tocopherols and phenols. In this paper, the isolation of phenolic compounds from virgin olive oil, by different methods, was tested and discussed. Particularly liquid-liquid and solid-phase extraction methods were compared, assaying, for the latter, three stationary phases (C8, C18 and Diol) and several elution mixtures. Quantification of phenolic and o-diphenolic substances in the extracts was performed by the traditional Folin-Ciocalteau method and the sodium molybdate reaction, respectively. Furthermore, the quantification of phenolic compounds in the extracts and in a standard mixture was carried out both with diode array and mass spectrometric detection and capillary zone electrophoresis.

Extraction Method and Analysis of Cannabinoids in Cannabis Olive Oil Preparations.

PubMed

Casiraghi, Antonella; Roda, Gabriella; Casagni, Eleonora; Cristina, Cecilia; Musazzi, Umberto Maria; Franzè, Silvia; Rocco, Paolo; Giuliani, Claudia; Fico, Gelsomina; Minghetti, Paola; Gambaro, Veniero

2018-03-01

Recently, an increasing number of pharmacists had to supply medicinal products based on Cannabis sativa L. (Cannabaceae), prescribed by physicians to individual patients. Cannabis olive oil preparation is the first choice as a concentrated extract of cannabinoids, even though standardized operative conditions for obtaining it are still not available. In this work, the impact of temperature and extraction time on the concentration of active principles was studied to harmonize the different compounding methods, optimize the extraction process, and reduce the variability among preparations. Moreover, starting from the cannabis inflorescence, the effect of temperature on tetrahydrocannabinolic acid decarboxylation was evaluated. For the analysis, a GC/MS method, as suggested by the Italian Ministry of Health, and a GC/flame ionization detection method were developed, validated, and compared. Georg Thieme Verlag KG Stuttgart · New York.

Rapid and cost-effective determination of acrylamide in coffee by planar chromatography and fluorescence detection after derivatization with dansulfinic acid.

PubMed

Alpmann, Alexander; Morlock, Gertrud

2009-01-01

A new method has been developed for the determination of acrylamide in ground coffee by planar chromatography using prechromatographic in situ derivatization with dansulfinic acid. After pressurized fluid extraction of acrylamide from the coffee samples, the extracts were passed through activated carbon and concentrated. These extracts were applied onto a silica gel 60 HPTLC plate and oversprayed with dansulfinic acid. By heating the plate, acrylamide was derivatized into the fluorescent product dansylpropanamide. The chromatographic separation with ethyl acetate-tert.-butyl methyl ether (8 + 2, v/v) mobile phase was followed by densitometric quantification at 254/>400 nm using a 4 point calibration via the standard addition method over the whole system for which acrylamide was added at different concentrations at the beginning of the extraction process. The method was validated for commercial coffee. The linearity over the whole procedure showed determination coefficients between 0.9995 and 0.9825 (n = 6). Limit of quantitation at a signal-to-noise ratio of 10 was determined to be 48 microg/kg. The within-run precision (relative standard deviation, n = 6) of the chromatographic method was 3%. Commercial coffee samples analyzed showed acrylamide contents between 52 and 191 microg/kg, which was in correlation with amounts reported in previous publications.

[HPLC method to determine DEHP released into blood from a disposable extracorporeal circulation tube].

PubMed

Liu, Xi; Yu, Jingjing; Li, Shen; Wang, Hong; Liu, Jiaxin

2013-08-01

We used blood as leaching medium, simulating clinical operation under maximum condition, to develop Liquid-phase extraction- High Performance Liquid Chromatography (HPLC) method for determination of plasticizer Di-(2-ethylhexyl)phthalate (DEHP) released from Disposable Extracorporeal Circulation Tube in order to lay the foundation of risk analysis of this product. The characteristic wavelength of DEHP in methanol was detected. Acetonitrile was added to the leaching blood in proportion and extracted DEHP from blood. The methodology for HPLC to quantify DEHP was established and the DEHP amount released from this disposable extracorporeal circulation tube was measured. The experiments showed good results as follows. The characteristic wavelength of DEHP was 272nm. The concentration of DEHP (5-250 microg/mL) kept good linear relationship with peak area (r=0.9999). Method sensitivity was 1 microg/mL. Precisions showed RSD<5%. The adding standard extraction Recovery Rates of 25, 100 and 250 microg DEHP standard were 61.91 +/- 3.32)%, (69.38 +/- 0.55)% and (68.47 +/- 1.15)%. The DEHP maximum amounts released from 3 sets of this disposable extracorporeal circulation tube were 204.14, 106.30 and 165.34 mg/set. Our Liquid-phase Extraction-HPLC method showed high accuracy and precision, and relatively stable recovery rate. Its operation was also convenient.

Phytopharmacological evaluation of ethanol extract of Sida cordifolia L. roots.

PubMed

Momin, Mohammad Abdul Motalib; Bellah, Sm Faysal; Rahman, Sarder Mohammad Raussel; Rahman, Ahmed Ayedur; Murshid, Gazi Mohammad Monjur; Emran, Talha Bin

2014-01-01

To investigate the phytochemical screening (group determination) and selected pharmacological activities (antioxidant, antimicrobial and analgesic activity) of the plant Sida cordifolia Linn (S. cordifolia). Eighty percent concentrated ethanol extract of the roots was used. To identify the chemical constituents of plant extract standard procedures were followed. In phytochemical screening the crude extract was tested for the presence of different chemical groups like reducing sugar, tannins, saponins, steroids, flavonoids, gums, alkaloids and glycosides. The antioxidant property of ethanolic extract of S. cordifolia was assessed by DPPH free radical scavenging activity. Analgesic activity of the extract was tested using the model of acetic acid induced writhing in mice. Diclofenac sodium is used as reference standard drug for the analgesic activity test. Antibacterial activity of plant extract was carried out using disc diffusion method with five pathogenic bacteria comparison with kanamycin as a standard. Phytochemical analysis of the ethanolic extract of the roots of S. cordifolia indicated the presence of reducing sugar, alkaloids, steroids and saponins. In DPPH scavenging assay the IC50 value was found to be 50 μg/mL which was not comparable to the standard ascorbic acid. The crude extract produced 44.30% inhibition of writhing at the dose of 500 mg/kg body weight which is statistically significant (P>0.001). The in vitro antimicrobial activity of the ethanol extract of the roots of S. cordifolia showed no antimicrobial activity against five types of microorganisms. The experiment was conducted only with five species of bacteria as test species, which do not at all indicate the total inactivity against micro-organisms. The obtained results provide a support for the use of this plant in traditional medicine but further pharmacological studies are required. Copyright © 2014 Asian Pacific Tropical Biomedical Magazine. Published by Elsevier B.V. All rights reserved.

Negative-pressure cavitation extraction for the determination of flavonoids in pigeon pea leaves by liquid chromatography-tandem mass spectrometry.

PubMed

Liu, Wei; Fu, Yujie; Zu, Yuangang; Kong, Yu; Zhang, Lin; Zu, Baishi; Efferth, Thomas

2009-05-01

A new method, namely negative-pressure cavitation extraction (NPCE), followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) is presented for the extraction and quantification of flavonoids in pigeon pea leaves. This method combines the high efficiency of NPCE and the sensitivity and accuracy of MS/MS. The influential parameters of the NPCE procedure including liquid/solid ratio, extraction time, nitrogen flow and number of extraction cycles were optimized. Under optimized conditions, the efficiency of NPCE for extracting five flavonoids was compared to microwave-assisted extraction (MAE), ultrasonic extraction (USE) and heating reflux extraction (HRE). Additionally, structural disruption to pigeon pea leaves samples with different extraction methods was investigated by scanning electron microscopy. The relative recovery with NPCE was equivalent to or higher than that with USE and obviously higher than those with MAE and HRE which are usually conducted in higher temperatures. Furthermore, because NPCE was performed with nitrogen at room temperature, the degradation and oxidation of analytes were avoided. In addition, the NPCE method was validated in terms of repeatability and reproducibility, relative standard deviation for relative recovery was lower than 5.84 and 8.83%, respectively. The method was also successfully applied for the quantification of five flavonoids in pigeon pea leaves. All these results suggest that the developed NPCE-LC-MS/MS method represents an excellent alternative for the extraction and quantification of flavonoids in other plant materials.

ALE: automated label extraction from GEO metadata.

PubMed

Giles, Cory B; Brown, Chase A; Ripperger, Michael; Dennis, Zane; Roopnarinesingh, Xiavan; Porter, Hunter; Perz, Aleksandra; Wren, Jonathan D

2017-12-28

NCBI's Gene Expression Omnibus (GEO) is a rich community resource containing millions of gene expression experiments from human, mouse, rat, and other model organisms. However, information about each experiment (metadata) is in the format of an open-ended, non-standardized textual description provided by the depositor. Thus, classification of experiments for meta-analysis by factors such as gender, age of the sample donor, and tissue of origin is not feasible without assigning labels to the experiments. Automated approaches are preferable for this, primarily because of the size and volume of the data to be processed, but also because it ensures standardization and consistency. While some of these labels can be extracted directly from the textual metadata, many of the data available do not contain explicit text informing the researcher about the age and gender of the subjects with the study. To bridge this gap, machine-learning methods can be trained to use the gene expression patterns associated with the text-derived labels to refine label-prediction confidence. Our analysis shows only 26% of metadata text contains information about gender and 21% about age. In order to ameliorate the lack of available labels for these data sets, we first extract labels from the textual metadata for each GEO RNA dataset and evaluate the performance against a gold standard of manually curated labels. We then use machine-learning methods to predict labels, based upon gene expression of the samples and compare this to the text-based method. Here we present an automated method to extract labels for age, gender, and tissue from textual metadata and GEO data using both a heuristic approach as well as machine learning. We show the two methods together improve accuracy of label assignment to GEO samples.

Multi-residue method for the determination of 450 pesticide residues in honey, fruit juice and wine by double-cartridge solid-phase extraction/gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry.

PubMed

Pang, G-F; Fan, C-L; Liu, Y-M; Cao, Y-Z; Zhang, J-J; Fu, B-L; Li, X-M; Li, Z-Y; Wu, Y-P

2006-08-01

A multi-residue method was developed for the determination of 450 pesticide residues in honey, fruit juice and wine using double-cartridge solid-phase extraction (SPE), gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS-MS). The method development was based on an appraisal of the characteristics of GC-MS and LC-MS-MS for 654 pesticides as well as the efficiency of extraction and purification from honey, fruit juice and wine. Samples were first diluted with water plus acetone, then extracted with portions of dichloromethane. The extracts were concentrated and cleaned up with graphitized carbon black and aminopropyl cartridges stacked in tandem. Pesticides were eluted with acetonitrile + toluene, and the eluates were concentrated. For 383 pesticides, the eluate was extracted with hexane twice and internal standard solution was added prior to GC-MS determination. For 67 pesticides, extraction was with methanol prior to LC-MS-MS determination. The limit of detection for the method was between 1.0 and 300 ng g(-1) depending on each pesticide analyte. At the three fortification levels of 2.0-3000 ng g(-1), the average recovery rates were between 59 and 123%, among which 413 pesticides (92% of the 450) had recovery rates of 70-120% and 35 pesticides (8% of the 450) had recovery rates of 59-70%. There were 437 pesticides (97% of the 450) with a relative standard deviation below 25%; there were 13 varieties (3% of the 450) between 25.0 and 30.4%.

Determination of Total Biotin by Liquid Chromatography Coupled with Immunoaffinity Column Cleanup Extraction: Multilaboratory Testing, Final Action 2016.02.

PubMed

Joseph, George; Devi, Ranjani; Marley, Elaine C; Leeman, David

2018-05-01

Single- and multilaboratory testing data have provided systematic scientific evidence that a simple, selective, accurate, and precise method can be used as a potential candidate reference method for dispute resolution in determining total biotin in all forms of infant, adult, and/or pediatric formula. Using LC coupled with immunoaffinity column cleanup extraction, the method fully meets the intended purpose and applicability statement in AOAC Standard Method Performance Requirement 2014.005. The method was applied to a cross-section of infant formula and adult nutritional matrixes, and acceptable precision and accuracy were established. The analytical platform is inexpensive, and the method can be used in almost any laboratory worldwide with basic facilities. The immunoaffinity column cleanup extraction is the key step to successful analysis.

A photometric method for the estimation of the oil yield of oil shale

USGS Publications Warehouse

Cuttitta, Frank

1951-01-01

A method is presented for the distillation and photometric estimation of the oil yield of oil-bearing shales. The oil shale is distilled in a closed test tube and the oil extracted with toluene. The optical density of the toluene extract is used in the estimation of oil content and is converted to percentage of oil by reference to a standard curve. This curve is obtained by relating the oil yields determined by the Fischer assay method to the optical density of the toluene extract of the oil evolved by the new procedure. The new method gives results similar to those obtained by the Fischer assay method in a much shorter time. The applicability of the new method to oil-bearing shale and phosphatic shale has been tested.

Anticodeine aptamer immobilized on a Whatman cellulose paper for thin-film microextraction of codeine from urine followed by electrospray ionization ion mobility spectrometry.

PubMed

Hashemian, Zahra; Khayamian, Taghi; Saraji, Mohammad

2015-02-01

A combination of thin-film microextaction based on an aptamer immobilized on modified Whatman cellulose paper followed by electrospray ionization ion mobility spectrometry has been developed for the analysis of codeine in urine samples. The immobilization is based on the covalent linking of an amino-modified anticodeine aptamer to aldehyde groups of the oxidized cellulose paper. The covalent bonds were examined by infrared spectroscopy and elemental analysis. The effect of the extraction parameters, including the elution conditions (solvent type and volume), extraction time, and extraction temperature, on the extraction efficiency were investigated. Under the optimized conditions, the linear dynamic range was found to be 10-300 ng/mL with a detection limit of 3.4 ng/mL for codeine in urine. The relative standard deviation was 6.8% for three replicate measurements of codeine at 100 ng/mL in urine. Furthermore, the samples were analyzed with a standard method for the analysis of codeine using high-performance liquid chromatography with ultraviolet detection. The comparison of the results validates the accuracy of the proposed method as an alternative method for the analysis of codeine in urine samples.

[Study on quality standard of Sophora flavescens root extract].

PubMed

Zhao, Feng-chun; Li, Hao; Chen, Liang-mian; Gao, Hui-min; Zhang, Qi-wei; Wang, Zhi-min; Wu, Pi-e

2015-01-01

As a part of the project for the Chinese Pharmacopoeia (2015 edition), the quality standard of Sophora flavescens root extract was investigated and established. According to the methods described in the Appendix of Chinese Pharmacopoeia (2010 edition), the water and ash inspections were carried out. The marker components trifolirhizin, sophoraflavanone G, oxymatrine and oxysophocarpine in the samples were identified by qualitative TLC. The determination of oxymatrine, matrine, oxysophocarpine and sophocarpine was conducted by HPLC and the total flavonoids were measured by ultraviolet spectrophotometry, using sophoraflavanone G as reference substance. The results indicated the spots on the plate were clear with good resolution and the contents of oxymatrine, matrine, oxysophocarpine and sophocarpine in the 13 batches of the samples were 3.87% - 11.1%, 0.970% - 4.33%, 1.30% - 2.59% and 0.260% - 1.14%, respectively. The total flavoids in the 13 batches of the samples were 3.88% - 7.93%. In the study, the validated methods were reproducible and the established quality standard was feasible, which could be used for the quality control of S. flavescens root extract and related preparations.

Automated extraction for the analysis of 11-nor-delta9-tetrahydrocannabinol-9-carboxylic acid (THCCOOH) in urine using a six-head probe Hamilton Microlab 2200 system and gas chromatography-mass spectrometry.

PubMed

Whitter, P D; Cary, P L; Leaton, J I; Johnson, J E

1999-01-01

An automated extraction scheme for the analysis of 11 -nor-delta9-tetrahydrocannabinol-9-carboxylic acid using the Hamilton Microlab 2200, which was modified for gravity-flow solid-phase extraction, has been evaluated. The Hamilton was fitted with a six-head probe, a modular valve positioner, and a peristaltic pump. The automated method significantly increased sample throughput, improved assay consistency, and reduced the time spent performing the extraction. Extraction recovery for the automated method was > 90%. The limit of detection, limit of quantitation, and upper limit of linearity were equivalent to the manual method: 1.5, 3.0, and 300 ng/mL, respectively. Precision at the 15-ng/mL cut-off was as follows: mean = 14.4, standard deviation = 0.5, coefficient of variation = 3.5%. Comparison of 38 patient samples, extracted by the manual and automated extraction methods, demonstrated the following correlation statistics: r = .991, slope 1.029, and y-intercept -2.895. Carryover was < 0.3% at 1000 ng/mL. Aliquoting/extraction time for the automated method (48 urine samples) was 50 min, and the manual procedure required approximately 2.5 h. The automated aliquoting/extraction method on the Hamilton Microlab 2200 and its use in forensic applications are reviewed.

CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING AIR SAMPLES FOR ANALYSIS OF POLAR PERSISTENT ORGANIC POLLUTANTS (SOP-5.13)

EPA Science Inventory

The method for extracting and preparing indoor and outdoor air samples for analysis of polar persistent organic pollutants is summarized in this SOP. It covers the preparation of samples that are to be analyzed by gas chromatography/mass spectrometry.

Use of fluorinated polybrominated diphenyl ethers and simplified cleanup for the analysis of polybrominated diphenyl ethers in house dust

EPA Science Inventory

A simple, cost-effective method is described for the analysis of polybrominated diphenyl ethers (PBDEs) in house dust using pressurized fluid extraction, cleanup with modified silica solid phase extraction tubes, and fluorinated internal standards. There are 14 PBDE congeners inc...

Accurate determination of 3-alkyl-2-methoxypyrazines in wines by gas chromatography quadrupole time-of-flight tandem mass spectrometry following solid-phase extraction and dispersive liquid-liquid microextraction.

PubMed

Fontana, Ariel; Rodríguez, Isaac; Cela, Rafael

2017-09-15

A new reliable method for the determination 3-alkyl-2-methoxypyrazines (MPs) in wine samples based on the sequential combination of solid-phase extraction (SPE), dispersive liquid-liquid microextraction (DLLME) and gas chromatography (GC) quadrupole time-of-flight accurate tandem mass spectrometry (QTOF-MS/MS) is presented. Primary extraction of target analytes was carried out by using a reversed-phase Oasis HLB (200mg) SPE cartridge combined with acetonitrile as elution solvent. Afterwards, the SPE extract was submitted to DLLME concentration using 0.06mL carbon tetrachloride (CCl 4 ) as extractant. Under final working conditions, sample concentration factors above 379 times and limits of quantification (LOQs) between 0.3 and 2.1ngL -1 were achieved. Moreover, the overall extraction efficiency of the method was unaffected by the particular characteristics of each wine; thus, accurate results (relative recoveries from 84 to 108% for samples spiked at concentrations from 5 to 25ngL -1 ) were obtained using matrix-matched standards, without using standard additions over every sample. Highly selective chromatographic records were achieved considering a mass window of 5mDa, centered in the quantification product ion corresponding to each compound. Twelve commercial wines, elaborated with grapes from different varieties and geographical origins, were processed with the optimized method. The 2-isobutyl-3-methoxypyrazine (IBMP) was determined at levels above the LOQs of the method in half of the samples. Copyright © 2017 Elsevier B.V. All rights reserved.

Method development for gypenosides fingerprint by high performance liquid chromatography with diode-array detection and the addition of internal standard.

PubMed

Liu, Fang; Ren, Dequan; Guo, De-an; Pan, Yifeng; Zhang, Huzhe; Hu, Ping

2008-03-01

In this paper, a new method for liquid chromatographic fingerprint of saponins in Gynostemma pentaphyllum (THUNB.) MAKINO was developed. The G. pentaphyllum powder was defatted by Soxhlet extraction with petroleum ether and then gypenosides were extracted from the residue with methanol by sonicating. Column chromatography with macro pore resin was then used to separate and enrich gypenosides. HPLC fingerprint analysis of gypenosides fraction was performed on a C18 column, with an isocratic elution of 34% acetonitrile for 60 min at 0.8 ml/min, sample injection volume was 20 microl and the wavelength was 203 nm. To cover the lack of standard compounds, the addition of an internal standard of ginsenoside Rb2 was employed in the gypenosides fingerprint profile. The relative retention time (RRT) and relative peak area (RPA) of the gypenosides peaks in the fingerprint were calculated by setting the ginsenoside Rb2 as the marker compound. The relative standard deviation (RSDs) of RRT of five common peaks vs. ginsenoside Rb2 in precision, repeatability and stability test were less than 1%, and the RSDs of RPA were less than 5%. The method validation data proved that the proposed method for the fingerprint with internal standard of G. pentaphyllum saponins is adequate, valid and applicable. Finally, three batches of crude drug samples collected from Shanxi province were tested by following the established method.

Successful isolation and PCR amplification of DNA from National Institute of Standards and Technology herbal dietary supplement standard reference material powders and extracts.

PubMed

Cimino, Matthew T

2010-03-01

Twenty-four herbal dietary supplement powder and extract reference standards provided by the National Institute of Standards and Technology (NIST) were investigated using three different commercially available DNA extraction kits to evaluate DNA availability for downstream nucleotide-based applications. The material included samples of Camellia, Citrus, Ephedra, Ginkgo, Hypericum, Serenoa, And Vaccinium. Protocols from Qiagen, MoBio, and Phytopure were used to isolate and purify DNA from the NIST standards. The resulting DNA concentration was quantified using SYBR Green fluorometry. Each of the 24 samples yielded DNA, though the concentration of DNA from each approach was notably different. The Phytopure method consistently yielded more DNA. The average yield ratio was 22 : 3 : 1 (ng/microL; Phytopure : Qiagen : MoBio). Amplification of the internal transcribed spacer II region using PCR was ultimately successful in 22 of the 24 samples. Direct sequencing chromatograms of the amplified material suggested that most of the samples were comprised of mixtures. However, the sequencing chromatograms of 12 of the 24 samples were sufficient to confirm the identity of the target material. The successful extraction, amplification, and sequencing of DNA from these herbal dietary supplement extracts and powders supports a continued effort to explore nucleotide sequence-based tools for the authentication and identification of plants in dietary supplements. (c) Georg Thieme Verlag KG Stuttgart . New York.

Nucleon-nucleon interactions via Lattice QCD: Methodology. HAL QCD approach to extract hadronic interactions in lattice QCD

NASA Astrophysics Data System (ADS)

Aoki, Sinya

2013-07-01

We review the potential method in lattice QCD, which has recently been proposed to extract nucleon-nucleon interactions via numerical simulations. We focus on the methodology of this approach by emphasizing the strategy of the potential method, the theoretical foundation behind it, and special numerical techniques. We compare the potential method with the standard finite volume method in lattice QCD, in order to make pros and cons of the approach clear. We also present several numerical results for nucleon-nucleon potentials.

Use of headspace sorptive extraction coupled to gas chromatography-mass spectrometry for the analysis of volatile polycyclic aromatic hydrocarbons in herbal infusions.

PubMed

Cacho, J I; Campillo, N; Viñas, P; Hernández-Córdoba, M

2014-08-22

A solvent-free method is described for the determination of 10 volatile polycyclic aromatic hydrocarbons (PAHs), considered as priority pollutants by the EU, in different herbal infusions using headspace sorptive extraction (HSSE) and gas chromatography-mass spectrometry (GC-MS). The parameters affecting both the extraction and thermal desorption steps in the HSSE were optimized by means of Plackett-Burman designs. Ten millilitres of the herbal infusion was submitted to the HSSE preconcentration in the presence of salt for 4h at 88 °C. The use of d(10)-phenanthrene as internal standard not only improved the repeatability of the method but allowed quantification of the samples against external aqueous standards. Detection limits ranged between 11 and 26 ng L(-1). Copyright © 2014 Elsevier B.V. All rights reserved.

Gas chromatography-mass spectrometry assay method for the therapeutic drug monitoring of the antiepileptic drug tiagabine.

PubMed

Chollet, D F; Castella, E; Goumaz, L; Anderegg, G

1999-11-01

A gas chromatography-mass spectrometry assay method suitable for the therapeutic drug monitoring of the antiepileptic drug tiagabine is described. Tiagabine and its desmethylated analogue used as internal standard were first extracted from serum by liquid-liquid extraction using an ethyl ether-isobutanol 98:2 mixture. Tiagabine and the internal standard were then methylated in the organic phase in presence of methanol by means of a safe and stable diazomethane derivative. After evaporation, the reconstituted extracts were chromatographed on a crosslinked phenyl methyl siloxane capillary column and detected by mass fragmentometry at m/z = 156. No other antiepileptic drug possibly administrated in polytherapy and no metabolite were found to interfere in the assay. The limit of quantification was 5 ng/ml. The precision and the accuracy were found to be suitable for the therapeutic drug monitoring of tiagabine.

Isolation and identification of arctiin and arctigenin in leaves of burdock (Arctium lappa L.) by polyamide column chromatography in combination with HPLC-ESI/MS.

PubMed

Liu, Shiming; Chen, Kaoshan; Schliemann, Willibald; Strack, Dieter

2005-01-01

A simple method involving polyamide column chromatography in combination with HPLC-PAD and HPLC-ESI/MS for isolating and identifying two kinds of lignans, arctiin and arctigenin, in the leaves of burdock (Arctium lappa L.) has been established. After extraction of burdock leaves with 80% methanol, the aqueous phase of crude extracts was partitioned between water and chloroform and the aqueous phase was fractionated on a polyamide glass column. The fraction, eluting with 100% methanol, was concentrated and gave a white precipitate at 4 degrees C from which two main compounds were purified by semi-preparative HPLC. In comparison with the UV and ESI-MS spectra and the HPLC retention time of authentic standards, the compounds were determined to be arctiin and arctigenin. The extraction/separation technique was validated using an internal standard method.

A Novel Extraction Method Combining Plasma with a Whole-Blood Fraction Shows Excellent Sensitivity and Reproducibility for Patients at High Risk for Invasive Aspergillosis

PubMed Central

Springer, Jan; Schloßnagel, Hannes; Heinz, Werner; Doedt, Thomas; Soeller, Rainer; Einsele, Hermann

2012-01-01

Diagnosis of invasive aspergillosis (IA) is still a major problem in routine clinical practice. Early diagnosis is essential for a good patient prognosis. PCR is a highly sensitive method for the detection of nucleic acids and could play an important role in improving the diagnosis of fungal infections. Therefore, a novel DNA extraction method, ultraclean production (UCP), was developed allowing purification of both cellular and cell-free circulating fungal DNA. In this prospective study we evaluated the commercially available UCP extraction system and compared it to an in-house system. Sixty-three patients at high risk for IA were screened twice weekly, and DNA extracted by both methods was cross-analyzed, in triplicate, by two different real-time PCR assays. The negative predictive values were high for all methods (94.3 to 100%), qualifying them as screening methods, but the sensitivity and diagnostic odds ratios were higher using the UCP extraction method. Sensitivity ranged from 33.3 to 66.7% using the in-house extracts to 100% using the UCP extraction method. Most of the unclassified patients showed no positive PCR results; however, single-positive PCR replicates were observed in some cases. These can bear clinical relevance but should be interpreted with additional clinical and laboratory data. The PCR assays from the UCP extracts showed greater reproducibility than the in-house method for probable IA patients. The standardized UCP extraction method yielded superior results, with regard to sensitivity and reproducibility, than the in-house method. This was independent of the PCR assay used to detect fungal DNA in the sample extracts. PMID:22593600

Analysis of acrylamide in coffee and cocoa by isotope dilution liquid chromatography-tandem mass spectrometry.

PubMed

Aguas, Patricia C; Fitzhenry, Matthew J; Giannikopoulos, Georgina; Varelis, Peter

2006-08-01

An accurate and precise method for the quantification of acrylamide using stable isotope dilution liquid chromatography-tandem mass spectrometry was developed and used to measure acrylamide in coffee and cocoa samples. The sample preparation involved extraction of the analyte and its internal standard, 13C3-acrylamide, into water and subsequent defatting of the aqueous extract with dichloromethane. An aliquot of the resulting aqueous extract was then azeotropically dried under reduced pressure and subsequently purified using an aminopropyl-bonded silica cartridge. The purified extracts were then chromatographed on a 5-microm 2.1 x 150 mm Hypercarb column, the effluent of which was monitored for the analyte and its internal standard using positive-ion APCI-selected reaction monitoring. The intra-laboratory reproducibility of the method, expressed as a relative coefficient of variation (%, n=5), was determined at four levels of concentration (12.3, 42.3, 139.3 and 464.8 microg kg(-1)) and was found to vary between 0.6-2.5%. The accuracy of the method was assessed using a reference sample of coffee. The average result obtained using our method differed from the assigned value of the reference material by less than 1%. An analysis of a cocoa sample revealed that the method is capable of precisely estimating acrylamide in challenging matrices down to a level of at least 12.3 microg kg(-1).

A fast and efficient method for device level layout analysis

NASA Astrophysics Data System (ADS)

Dong, YaoQi; Zou, Elaine; Pang, Jenny; Huang, Lucas; Yang, Legender; Zhang, Chunlei; Du, Chunshan; Hu, Xinyi; Wan, Qijian

2017-03-01

There is an increasing demand for device level layout analysis, especially as technology advances. The analysis is to study standard cells by extracting and classifying critical dimension parameters. There are couples of parameters to extract, like channel width, length, gate to active distance, and active to adjacent active distance, etc. for 14nm technology, there are some other parameters that are cared about. On the one hand, these parameters are very important for studying standard cell structures and spice model development with the goal of improving standard cell manufacturing yield and optimizing circuit performance; on the other hand, a full chip device statistics analysis can provide useful information to diagnose the yield issue. Device analysis is essential for standard cell customization and enhancements and manufacturability failure diagnosis. Traditional parasitic parameters extraction tool like Calibre xRC is powerful but it is not sufficient for this device level layout analysis application as engineers would like to review, classify and filter out the data more easily. This paper presents a fast and efficient method based on Calibre equation-based DRC (eqDRC). Equation-based DRC extends the traditional DRC technology to provide a flexible programmable modeling engine which allows the end user to define grouped multi-dimensional feature measurements using flexible mathematical expressions. This paper demonstrates how such an engine and its programming language can be used to implement critical device parameter extraction. The device parameters are extracted and stored in a DFM database which can be processed by Calibre YieldServer. YieldServer is data processing software that lets engineers query, manipulate, modify, and create data in a DFM database. These parameters, known as properties in eqDRC language, can be annotated back to the layout for easily review. Calibre DesignRev can create a HTML formatted report of the results displayed in Calibre RVE which makes it easy to share results among groups. This method has been proven and used in SMIC PDE team and SPICE team.

Multivariate EMD and full spectrum based condition monitoring for rotating machinery

NASA Astrophysics Data System (ADS)

Zhao, Xiaomin; Patel, Tejas H.; Zuo, Ming J.

2012-02-01

Early assessment of machinery health condition is of paramount importance today. A sensor network with sensors in multiple directions and locations is usually employed for monitoring the condition of rotating machinery. Extraction of health condition information from these sensors for effective fault detection and fault tracking is always challenging. Empirical mode decomposition (EMD) is an advanced signal processing technology that has been widely used for this purpose. Standard EMD has the limitation in that it works only for a single real-valued signal. When dealing with data from multiple sensors and multiple health conditions, standard EMD faces two problems. First, because of the local and self-adaptive nature of standard EMD, the decomposition of signals from different sources may not match in either number or frequency content. Second, it may not be possible to express the joint information between different sensors. The present study proposes a method of extracting fault information by employing multivariate EMD and full spectrum. Multivariate EMD can overcome the limitations of standard EMD when dealing with data from multiple sources. It is used to extract the intrinsic mode functions (IMFs) embedded in raw multivariate signals. A criterion based on mutual information is proposed for selecting a sensitive IMF. A full spectral feature is then extracted from the selected fault-sensitive IMF to capture the joint information between signals measured from two orthogonal directions. The proposed method is first explained using simple simulated data, and then is tested for the condition monitoring of rotating machinery applications. The effectiveness of the proposed method is demonstrated through monitoring damage on the vane trailing edge of an impeller and rotor-stator rub in an experimental rotor rig.

Development of Hospital-based Data Sets as a Vehicle for Implementation of a National Electronic Health Record

PubMed Central

Keikha, Leila; Farajollah, Seyede Sedigheh Seied; Safdari, Reza; Ghazisaeedi, Marjan; Mohammadzadeh, Niloofar

2018-01-01

Background In developing countries such as Iran, international standards offer good sources to survey and use for appropriate planning in the domain of electronic health records (EHRs). Therefore, in this study, HL7 and ASTM standards were considered as the main sources from which to extract EHR data. Objective The objective of this study was to propose a hospital data set for a national EHR consisting of data classes and data elements by adjusting data sets extracted from the standards and paper-based records. Method This comparative study was carried out in 2017 by studying the contents of the paper-based records approved by the health ministry in Iran and the international ASTM and HL7 standards in order to extract a minimum hospital data set for a national EHR. Results As a result of studying the standards and paper-based records, a total of 526 data elements in 174 classes were extracted. An examination of the data indicated that the highest number of extracted data came from the free text elements, both in the paper-based records and in the standards related to the administrative data. The major sources of data extracted from ASTM and HL7 were the E1384 and Hl7V.x standards, respectively. In the paper-based records, data were extracted from 19 forms sporadically. Discussion By declaring the confidentiality of information, the ASTM standards acknowledge the issue of confidentiality of information as one of the main challenges of EHR development, and propose new types of admission, such as teleconference, tele-video, and home visit, which are inevitable with the advent of new technology for providing healthcare and treating diseases. Data related to finance and insurance, which were scattered in different categories by three organizations, emerged as the financial category. Documenting the role and responsibility of the provider by adding the authenticator/signature data element was deemed essential. Conclusion Not only using well-defined and standardized data, but also adapting EHR systems to the local facilities and the existing social and cultural conditions, will facilitate the development of structured data sets. PMID:29618962

Development of a rapid method for the sequential extraction and subsequent quantification of fatty acids and sugars from avocado mesocarp tissue.

PubMed

Meyer, Marjolaine D; Terry, Leon A

2008-08-27

Methods devised for oil extraction from avocado (Persea americana Mill.) mesocarp (e.g., Soxhlet) are usually lengthy and require operation at high temperature. Moreover, methods for extracting sugars from avocado tissue (e.g., 80% ethanol, v/v) do not allow for lipids to be easily measured from the same sample. This study describes a new simple method that enabled sequential extraction and subsequent quantification of both fatty acids and sugars from the same avocado mesocarp tissue sample. Freeze-dried mesocarp samples of avocado cv. Hass fruit of different ripening stages were extracted by homogenization with hexane and the oil extracts quantified for fatty acid composition by GC. The resulting filter residues were readily usable for sugar extraction with methanol (62.5%, v/v). For comparison, oil was also extracted using the standard Soxhlet technique and the resulting thimble residue extracted for sugars as before. An additional experiment was carried out whereby filter residues were also extracted using ethanol. Average oil yield using the Soxhlet technique was significantly (P < 0.05) higher than that obtained by homogenization with hexane, although the difference remained very slight, and fatty acid profiles of the oil extracts following both methods were very similar. Oil recovery improved with increasing ripeness of the fruit with minor differences observed in the fatty acid composition during postharvest ripening. After lipid removal, methanolic extraction was superior in recovering sucrose and perseitol as compared to 80% ethanol (v/v), whereas mannoheptulose recovery was not affected by solvent used. The method presented has the benefits of shorter extraction time, lower extraction temperature, and reduced amount of solvent and can be used for sequential extraction of fatty acids and sugars from the same sample.

Classification and pose estimation of objects using nonlinear features

NASA Astrophysics Data System (ADS)

Talukder, Ashit; Casasent, David P.

1998-03-01

A new nonlinear feature extraction method called the maximum representation and discrimination feature (MRDF) method is presented for extraction of features from input image data. It implements transformations similar to the Sigma-Pi neural network. However, the weights of the MRDF are obtained in closed form, and offer advantages compared to nonlinear neural network implementations. The features extracted are useful for both object discrimination (classification) and object representation (pose estimation). We show its use in estimating the class and pose of images of real objects and rendered solid CAD models of machine parts from single views using a feature-space trajectory (FST) neural network classifier. We show more accurate classification and pose estimation results than are achieved by standard principal component analysis (PCA) and Fukunaga-Koontz (FK) feature extraction methods.

[Determination of five arsenic species in rice by liquid chromatography-inductively coupled plasma-mass spectrometry].

PubMed

Gong, Jiadi; Cao, Xiaolin; Cao, Zhaoyun; Bian, Yingfang; Yu, Shasha; Chen, Mingxue

2014-07-01

A method was developed for the simultaneous determination of arsenic acid [As (V)], arsenious acid [As (III)], arsenobetaine (AsB), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) in rice by liquid chromatography-inductively coupled plasma-mass spectrometry (LC-ICP-MS). The extraction reagent was 0.3 mol/L nitric acid with heat-assistant condition for 1.5 h at 95 degrees C. Then, the five arsenic species were separated by an anion exchange column (Dionex IonPac AS19, 250 mm x 4 mm) and detected by ICP-MS. Four kinds of extracted solutions were compared through the extraction efficiency. The concentration of nitric acid, the temperature and the extraction time were optimized. The recoveries of the five arsenic species spiked in rice at two levels ranged from 89.6% to 99.5% with the relative standard deviations (RSDs, n = 5) of 0.6% - 3.6%. The measured values of the arsenic species in standard rice materials were consistent with their standard values. The linear ranges were 0.05 - 200 microg/L for AsB and DMA, 0.10-400 microg/L for As (III) and MMA, 0.15-600 microg/L for As (V). The limits of detection for the five arsenic species were 0.15-0.45 microg/kg. The results showed that the method is much more precise for the risk assessment of the rice. This method is simple, accurate and durable for the determination of arsenic species in rice.

Quantification of drugs in plasma without primary reference standards by liquid chromatography-chemiluminescence nitrogen detection: application to tramadol metabolite ratios.

PubMed

Ojanperä, Suvi; Rasanen, Ilpo; Sistonen, Johanna; Pelander, Anna; Vuori, Erkki; Ojanperä, Ilkka

2007-08-01

Lack of availability of reference standards for drug metabolites, newly released drugs, and illicit drugs hinders the analysis of these substances in biologic samples. To counter this problem, an approach is presented here for quantitative drug analysis in plasma without primary reference standards by liquid chromatography-chemiluminescence nitrogen detection (LC-CLND). To demonstrate the feasibility of the method, metabolic ratios of the opioid drug tramadol were determined in the setting of a pharmacogenetic study. Four volunteers were given a single 100-mg oral dose of tramadol, and a blood sample was collected from each subject 1 hour later. Tramadol, O-desmethyltramadol, and nortramadol were determined in plasma by LC-CLND without reference standards and by a gas chromatography-mass spectrometry reference method. In contrast to previous CLND studies lacking an extraction step, a liquid-liquid extraction system was created for 5-mL plasma samples using n-butyl chloride-isopropyl alcohol (98 + 2) at pH 10. Extraction recovery estimation was based on model compounds chosen according to their similar physicochemical characteristics (retention time, pKa, logD). Instrument calibration was performed with a single secondary standard (caffeine) using the equimolar response of the detector to nitrogen. The mean differences between the results of the LC-CLND and gas chromatography-mass spectrometry methods for tramadol, O-desmethyltramadol, and nortramadol were 8%, 32%, and 19%, respectively. The sensitivity of LC-CLND was sufficient for therapeutic concentrations of tramadol and metabolites. A good correlation was obtained between genotype, expressed by the number of functional genes, and the plasma metabolite ratios. This experiment suggests that a recovery-corrected LC-CLND analysis produces sufficiently accurate results to be useful in a clinical context, particularly in instances in which reference standards are not readily accessible.

Acetylcholinesterase enzyme inhibitory potential of standardized extract of Trigonella foenum graecum L and its constituents.

PubMed

Satheeshkumar, N; Mukherjee, Pulok K; Bhadra, S; Saha, B P

2010-03-01

Ethno pharmacological approach has provided several leads to identify potential new drugs from plant sources, including those for memory disorders. Acetylcholinesterase inhibitors (AChEI) give a symptomatic relief to some of the clinical manifestations of the disease. The main objective of this study is to standardize the extract of Trigonella foenum graecum L with trigonelline by HPTLC method and determine the in vitro AChE inhibitory activity of Trigonella foenum graecum L and its constituents using galanthamine as a reference. Different concentrations of hydro alcoholic extract of Trigonella foenum graecum and trigonelline were subjected to HPTLC analysis using the mobile phase n propanol, methanol and water (4:1:2, v/v). The R(f) of trigonelline was found to be 0.43, and the correlation coefficient of 0.99 was indicative of good linear dependence of peak area on concentration. The concentration of trigonelline was found to be 13mgg(-1)w/w in the hydro alcoholic extract of Trigonella foenum graecum. The AChE inhibitory activity of crude fenugreek seed extracts, fractions and trigonelline was evaluated using Ellman's method in 96-well micro plate's assay and TLC bioassay detection. The ethyl acetate fraction of the alcohol extract (IC50 53.00 +/- 17.33microg/ml), and total alkaloid fraction (IC50 9.23+/-6.08microg/ml) showed potential AChE inhibition. Trigonelline showed IC50 233+/-0.12microM. Galanthamine was used as standard and it showed inhibition of acetyl cholinesterase with an IC50 value of 1.27+/-0.21microM. Copyright 2009 Elsevier GmbH. All rights reserved.

[Determination of 23 antibiotics and 3 β-agonists in livestock drinking water by ultra performance liquid chromatography-tandem mass spectrometry coupled with solid-phase extraction].

PubMed

Shi, Ao

2016-02-01

A method has been developed for the simultaneous determination of 23 antibiotics (four categories) and 3 β-agonists in livestock drinking water using solid-phase extraction and ultra performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI MS/MS). The samples were adjusted pH to 5. 0, added Na2EDTA, enriched and cleaned-up by an HLB solid-phase extraction cartridge. The target compounds were confirmed and quantified by UPLC-ESI MS/MS with external standard method for the anti- biotics and internal standard method for the β-agonists. The recoveries were assessed by using lab tap water as matrix. The average recoveries of the 23 antibiotics and the 3 β-agonists were in the range of 50. 7%-104. 6% and the relative standard deviations (RSDs) were 2. 6%-8. 8% (n= 3). Under the optimal conditions, the calibration curves of the 23 antibiotics and the 3 β-agonists showed good linearity with the correlation coefficients better than 0. 994. The limits of detection (LODs, S/N≥3) ranged from 0. 01-0. 20 ng/L. The developed method was applied to analyze the livestock drinking waters in 36 Beijing intensive livestock farms. The results showed that some antibiotics were detected.

Determination of polychlorinated biphenyls in fish: optimisation and validation of a method based on accelerated solvent extraction and gas chromatography-mass spectrometry.

PubMed

Ottonello, Giuliana; Ferrari, Angelo; Magi, Emanuele

2014-01-01

A simple and robust method for the determination of 18 polychlorinated biphenyls (PCBs) in fish was developed and validated. A mixture of acetone/n-hexane (1:1, v/v) was selected for accelerated solvent extraction (ASE). After the digestion of fat, the clean-up was carried out using solid phase extraction silica cartridges. Samples were analysed by GC-MS in selected ion monitoring (SIM) using three fragment ions for each congener (one quantifier and two qualifiers). PCB 155 and PCB 198 were employed as internal standards. The lowest limit of detection was observed for PCB 28 (0.4ng/g lipid weight). The accuracy of the method was verified by means of the Certified Reference Material EDF-2525 and good results in terms of linearity (R(2)>0.994) and recoveries (80-110%) were also achieved. Precision was evaluated by spiking blank samples at 4, 8 and 12ng/g. Relative standard deviation values for repeatability and reproducibility were lower than 8% and 16%, respectively. The method was applied to the determination of PCBs in 80 samples belonging to four Mediterranean fish species. The proposed procedure is particularly effective because it provides good recoveries with lowered extraction time and solvent consumption; in fact, the total time of extraction is about 12min per sample and, for the clean-up step, a total solvent volume of 13ml is required. Copyright © 2013 Elsevier Ltd. All rights reserved.

Automatic Recognition of Fetal Facial Standard Plane in Ultrasound Image via Fisher Vector.

PubMed

Lei, Baiying; Tan, Ee-Leng; Chen, Siping; Zhuo, Liu; Li, Shengli; Ni, Dong; Wang, Tianfu

2015-01-01

Acquisition of the standard plane is the prerequisite of biometric measurement and diagnosis during the ultrasound (US) examination. In this paper, a new algorithm is developed for the automatic recognition of the fetal facial standard planes (FFSPs) such as the axial, coronal, and sagittal planes. Specifically, densely sampled root scale invariant feature transform (RootSIFT) features are extracted and then encoded by Fisher vector (FV). The Fisher network with multi-layer design is also developed to extract spatial information to boost the classification performance. Finally, automatic recognition of the FFSPs is implemented by support vector machine (SVM) classifier based on the stochastic dual coordinate ascent (SDCA) algorithm. Experimental results using our dataset demonstrate that the proposed method achieves an accuracy of 93.27% and a mean average precision (mAP) of 99.19% in recognizing different FFSPs. Furthermore, the comparative analyses reveal the superiority of the proposed method based on FV over the traditional methods.

Effect of three extraction techniques on submitochondrial particle and Microtox bioassays for airborne particulate matter.

PubMed

Torres-Pérez, Mónica I; Jiménez-Velez, Braulio D; Mansilla-Rivera, Imar; Rodríguez-Sierra, Carlos J

2005-03-01

The effect that three extraction techniques (e.g., Soxhlet, ultrasound and microwave-assisted extraction) have on the toxicity, as measured by submitochondrial particle (SMP) and Microtox assays, of organic extracts was compared from three sources of airborne particulate matter (APM). The extraction technique influenced the toxicity response of APM extracts and it was dependent on the bioassay method, and APM sample source. APM extracts from microwave-assisted extraction (MAE) were similar or more toxic than the conventional extraction techniques of Soxhlet and ultrasound, thus, providing an alternate extraction method. The microwave extraction technique has the advantage of using less solvent volume, less extraction time, and the capacity to simultaneously extract twelve samples. The ordering of APM toxicity was generally urban dust > diesel dust > PM10 (particles with diameter < 10 microm), thus, reflecting different chemical composition of the samples. This study is the first to report the suitability of two standard in-vitro bioassays for the future toxicological characterization of APM collected from Puerto Rico, with the SMP generally showing better sensitivity to the well-known Microtox bioassay.

Dispersive solid-phase extraction for the determination of trace organochlorine pesticides in apple juices using reduced graphene oxide coated with ZnO nanocomposites as sorbent.

PubMed

Sun, Ting; Sun, Hefeng; Zhao, Feng

2017-09-01

In this work, reduced graphene oxide coated with ZnO nanocomposites was used as an efficient sorbent of dispersive solid-phase extraction and successfully applied for the extraction of organochlorine pesticides from apple juice followed by gas chromatography with mass spectrometry. Several experimental parameters affecting the extraction efficiencies, including the amount of adsorbent, extraction time, and the pH of the sample solution, as well as the type and volume of eluent solvent, were investigated and optimized. Under the optimal experimental conditions, good linearity existed in the range of 1.0-200.0 ng/mL for all the analytes with the correlation coefficients (R 2 ) ranging from 0.9964 to 0.9994. The limits of detection of the method for the compounds were 0.011-0.053 ng/mL. Good reproducibilities were acquired with relative standard deviations below 8.7% for both intraday and interday precision. The recoveries of the method were in the range of 78.1-105.8% with relative standard deviations of 3.3-6.9%. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Intercomparison of Lab-Based Soil Water Extraction Methods for Stable Water Isotope Analysis

NASA Astrophysics Data System (ADS)

Pratt, D.; Orlowski, N.; McDonnell, J.

2016-12-01

The effect of pore water extraction technique on resultant isotopic signature is poorly understood. Here we present results of an intercomparison of five common lab-based soil water extraction techniques: high pressure mechanical squeezing, centrifugation, direct vapor equilibration, microwave extraction, and cryogenic extraction. We applied five extraction methods to two physicochemically different standard soil types (silty sand and clayey loam) that were oven-dried and rewetted with water of known isotopic composition at three different gravimetric water contents (8, 20, and 30%). We tested the null hypothisis that all extraction techniques would provide the same isotopic result independent from soil type and water content. Our results showed that the extraction technique had a significant effect on the soil water isotopic composition. Each method exhibited deviations from spiked reference water, with soil type and water content showing a secondary effect. Cryogenic extraction showed the largest deviations from the reference water, whereas mechanical squeezing and centrifugation provided the closest match to the reference water for both soil types. We also compared results for each extraction technique that produced liquid water on both an OA-ICOS and IRMS; differences between them were negligible.

Polymeric ionic liquid based on magnetic materials fabricated through layer-by-layer assembly as adsorbents for extraction of pesticides.

PubMed

He, Lijun; Cui, Wenhang; Wang, Yali; Zhao, Wenjie; Xiang, Guoqiang; Jiang, Xiuming; Mao, Pu; He, Juan; Zhang, Shusheng

2017-11-03

In this study, layer-by-layer assembly of polyelectrolyte multilayer films on magnetic silica provided a convenient and controllable way to prepare polymeric ionic liquid-based magnetic adsorbents. The resulting particles were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and magnetic measurements. The data showed that the magnetic particles had more homogeneous spherical shapes with higher saturation magnetization when compared to those obtained by free radical polymerization method. This facilitated the convenient collection of magnetic particles, with higher extraction repeatability. The extraction performance of the multilayer polymeric ionic liquid-based adsorbents was evaluated by magnetic solid-phase extraction of four pesticides including quinalphos, fenthion, phoxim, and chlorpropham. The data suggested that the extraction efficiency depended on the number of layers in the film. The parameters affecting the extraction efficiency were optimized, and good linearity ranging from 2 to 250μgL -1 was obtained with correlation coefficients of 0.9994-0.9998. Moreover, the proposed method presented low limit of detection (0.5μgL -1 , S/N=3) and limit of quantification (1.5μgL -1 , S/N=10), and good repeatability expressed by the relative standard deviation (2.0%-4.6%, n=5). The extraction recoveries of four pesticides were found to range from 58.9% to 85.8%. The reliability of the proposed method was demonstrated by analyzing environmental water samples, and the results revealed satisfactory spiked recovery, relative standard deviation, and selectivity. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of analgesic, antipyretic and anti-inflammatory activity on Cordia dichotoma G. Forst. Leaf

PubMed Central

Gupta, Richa; Kaur, Jagjit

2015-01-01

Background: Cordia dichotoma G. Forst. is an important medicinal plant of family Boraginaceae. Traditionally, its leaves are used to treat fever, headache, and joint pain but its medicinal activities have not been proven by research. Objective: To evaluate the analgesic, anti-inflammatory, and antipyretic activity of C. dichotoma G. Forst. leaf extract. Material and Methods: The various extracts of leaf powder were prepared by using soxhlet apparatus. The methanol extract was selected for pharmacological study. To evaluate analgesic activity, Eddy's hot plate method, to study anti-inflammatory activity, carageenan-induced rat paw edema method, and to study antipyretic activity, yeast-induced pyrexia method was used. SD female rats (180-200 g) were used for the study. Results: In all three tests, the methanol extract high dose (400 mg/kg) was found to be highly significant as compared to standard drug. Conclusion: This study proved the traditional uses of plant leaves and concluded the analgesic, anti-inflammatory, and antipyretic activity of the leaf methanol extract. PMID:25598647

Influence of cultivation conditions, season of collection and extraction method on the content of antileishmanial flavonoids from Kalanchoe pinnata.

PubMed

Muzitano, Michelle F; Bergonzi, Maria Camilla; De Melo, Giany O; Lage, Celso L S; Bilia, Anna Rita; Vincieri, Franco F; Rossi-Bergmann, Bartira; Costa, Sônia S

2011-01-07

Leaves from Kalanchoe pinnata (Lamarck) Persoon (Crassulaceae) are popularly used for healing wounds. Its antileishmanial properties are established in experimental animals, and its active flavonoid components have been identified. In this study, we attempted to standardize the extract from K. pinnata leaves by evaluating the influence of season of harvest, sunlight exposure and method of extraction on antileishmanial flavonoids content. HPLC-DAD-MS was used to identify and quantify the active antileishmanial flavonoids in different extracts. ANOVA test for analyses of variance followed by the Tukey test of multiple comparisons were used in the statistical analysis. The antileishmanial potential was assessed by the activation of nitric oxide production by murine macrophage using the Griess method. We demonstrated that active flavonoids were significantly more abundant when the leaves were collected in the summer, and that aqueous extraction at 50°C allowed the highest flavonoid extraction. The benefit of sunlight exposure was confirmed in plants cultivated under direct sunlight when compared with those that grown under shade. Under sunny conditions the yield of the most active antileishmanial favonoid quercitrin was increased by 7-fold. All aqueous extracts tested were capable to enhance the macrophage nitric oxide production. However, hot aqueous extract from leaves collected in summer exhibited the higher activity, in agreement with HPLC-DAD-MS analysis tendency. In addition, with the aim of reducing the individual chemical variations of the plant constituents and optimizing the production of the active extract, it was obtained in vitro monoclonal KP specimens that were easily adapted to field conditions and were able to produce antileishmanial flavonoids. Our study reports the better conditions of cultivation, harvest and extraction protocol for obtaining a K. pinnata extract exhibiting the highest antileishmanial activity. Additionally, we propose the flavonoids quercetin 3-O-α-L-arabinopyranosyl (1→2)-α-L-rhamnopyranoside and quercitrin, as satisfactory chemical markers for standardization purposes. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Quantitative determination of superoxide in plant leaves using a modified NBT staining method.

PubMed

Bournonville, Carlos F Grellet; Díaz-Ricci, Juan Carlos

2011-01-01

In plants, the ROS (reactive oxygen species) level is tightly regulated because their accumulation produces irreversible damage leading to cell death. However, ROS accumulation plays a key role in plant signaling under biotic or abiotic stress. Although various methods were reported to evaluate ROS accumulation, they are restricted to model plants or provide only qualitative information. Develop a simple method to quantify superoxide radicals produced in plant tissues, based on the selective extraction of the formazan produced after nitroblue tetrazolium (NBT) reduction in histochemical staining. Plant leaves were stained with a standard NBT method and the formazan precipitated in tissues was selectively extracted using chloroform. The organic phase was dried and formazan residue dissolved in dimethylsulfoxide-potassium hydroxide and quantified by spectrophotometry. The method was tested in strawberry plant leaves under different stressing conditions. Formazan extracted from leaves subjected to stress conditions showed similar absorption spectra to those obtained from standard solutions using pure formazan. Calibration curves showed a linear relationship between absorbance and formazan amounts, within the range 0.5-8 µg. Outcomes suggested that formazan was retained in the solid residue of leaf tissues. This protocol allowed us to quantify superoxide radicals produced under different stress conditions. Chloroform allowed a selective formazan extraction and removal of potential endogenous, exogenous or procedural artefacts that may interfere with the quantitative determination. This protocol can be used to quantify the superoxide produced in plant tissues using any traditional qualitative NBT histochemical staining method. Copyright © 2011 John Wiley & Sons, Ltd.

Solid phase extraction of 2,4-D from human urine.

PubMed

Thompson, T S; Treble, R G

1996-10-01

A method for determining urinary concentrations of 2,4-D in samples collected from non-occupationally, environmentally exposed individuals was developed. The 2,4-D was extracted from fortified human urine samples using octadecylsilane solid phase extraction cartridges. The average percent recovery for urine samples spiked at 2 and 20 ng/mL was 100% and 93%, respectively. The method detection limit was estimated to be 0.75 ng of 2,4-D per mL of urine based on a 10 mL sample size. The potential use of 2,4-dichlorophenylacetic acid as a surrogate standard was also investigated.

An on-spot internal standard addition approach for accurately determining colistin A and colistin B in dried blood spots using ultra high-performance liquid chromatography-tandem mass spectrometry.

PubMed

Tsai, I-Lin; Kuo, Ching-Hua; Sun, Hsin-Yun; Chuang, Yu-Chung; Chepyala, Divyabharathi; Lin, Shu-Wen; Tsai, Yun-Jung

2017-10-25

Outbreaks of multidrug-resistant Gram-negative bacterial infections have been reported worldwide. Colistin, an antibiotic with known nephrotoxicity and neurotoxicity, is now being used to treat multidrug-resistant Gram-negative strains. In this study, we applied an on-spot internal standard addition approach coupled with an ultra high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify colistin A and B from dried blood spots (DBSs). Only 15μL of whole blood was required for each sample. An internal standard with the same yield of extraction recoveries as colistin was added to the spot before sample extraction for accurate quantification. Formic acid in water (0.15%) with an equal volume of acetonitrile (50:50v/v) was used as the extraction solution. With the optimized extraction process and LC-MS/MS conditions, colistin A and B could be quantified from a DBS with respective limits of quantification of 0.13 and 0.27μgmL -1 , and the retention times were < 2min. The relative standard deviations of within-run and between-run precisions for peak area ratios were all < 17.3%. Accuracies were 91.5-111.2% for lower limit of quantification, low, medium, and high QC samples. The stability of the easily hydrolyzed prodrug, colistin methanesulfonate, was investigated in DBSs. Less than 4% of the prodrug was found to be hydrolyzed in DBSs at room temperature after 48h. The developed method applied an on-spot internal standard addition approach which benefited the precision and accuracy. Results showed that DBS sampling coupled with the sensitive LC-MS/MS method has the potential to be an alternative approach for colistin quantification, where the bias of prodrug hydrolysis in liquid samples is decreased. Copyright © 2017 Elsevier B.V. All rights reserved.

EXTRACT: Interactive extraction of environment metadata and term suggestion for metagenomic sample annotation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pafilis, Evangelos; Buttigieg, Pier Luigi; Ferrell, Barbra

The microbial and molecular ecology research communities have made substantial progress on developing standards for annotating samples with environment metadata. However, sample manual annotation is a highly labor intensive process and requires familiarity with the terminologies used. We have therefore developed an interactive annotation tool, EXTRACT, which helps curators identify and extract standard-compliant terms for annotation of metagenomic records and other samples. Behind its web-based user interface, the system combines published methods for named entity recognition of environment, organism, tissue and disease terms. The evaluators in the BioCreative V Interactive Annotation Task found the system to be intuitive, useful, wellmore » documented and sufficiently accurate to be helpful in spotting relevant text passages and extracting organism and environment terms. Here the comparison of fully manual and text-mining-assisted curation revealed that EXTRACT speeds up annotation by 15–25% and helps curators to detect terms that would otherwise have been missed.« less

EXTRACT: Interactive extraction of environment metadata and term suggestion for metagenomic sample annotation

DOE PAGES

Pafilis, Evangelos; Buttigieg, Pier Luigi; Ferrell, Barbra; ...

2016-01-01

The microbial and molecular ecology research communities have made substantial progress on developing standards for annotating samples with environment metadata. However, sample manual annotation is a highly labor intensive process and requires familiarity with the terminologies used. We have therefore developed an interactive annotation tool, EXTRACT, which helps curators identify and extract standard-compliant terms for annotation of metagenomic records and other samples. Behind its web-based user interface, the system combines published methods for named entity recognition of environment, organism, tissue and disease terms. The evaluators in the BioCreative V Interactive Annotation Task found the system to be intuitive, useful, wellmore » documented and sufficiently accurate to be helpful in spotting relevant text passages and extracting organism and environment terms. Here the comparison of fully manual and text-mining-assisted curation revealed that EXTRACT speeds up annotation by 15–25% and helps curators to detect terms that would otherwise have been missed.« less

Effects of ultrahigh pressure extraction on yield and antioxidant activity of chlorogenic acid and cynaroside extracted from flower buds of Lonicera japonica.

PubMed

Hu, Wen; Guo, Ting; Jiang, Wen-Jun; Dong, Guang-Li; Chen, Da-Wei; Yang, Shi-Lin; Li, He-Ran

2015-06-01

The present study was designed to establish and optimize a new method for extracting chlorogenic acid and cynaroside from Lonicera japonica Thunb. through orthogonal experimental designl. A new ultrahigh pressure extraction (UPE) technology was applied to extract chlorogenic acid and cynaroside from L. japonica. The influential factors, including solvent type, ethanol concentration, extraction pressure, time, and temperature, and the solid/liquid ratio, have been studied to optimize the extraction process. The optimal conditions for the UPE were developed by quantitative analysis of the extraction products by HPLC-DAD in comparison with standard samples. In addition, the microstructures of the medicinal materials before and after extraction were studied by scanning electron microscopy (SEM). Furthermore, the extraction efficiency of different extraction methods and the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities of the extracts were investigated. The optimal conditions for extracting chlorogenic acid and cynaroside were as follows: ethanol concentration, 60%; extraction pressure, 400 MPa; extraction time, 2 min; extraction temperature, 30 °C; and the solid/liquid ratio, 1 : 50. Under these conditions, the yields of chlorogenic acid and cynaroside were raised to 4.863% and 0.080%, respectively. Compared with other extraction methods, such as heat reflux extraction (HRE), ultrasonic extraction (UE), and Sohxlet extraction (SE), the UPE method showed several advantages, including higher extraction yield, shorter extraction time, lower energy consumption, and higher purity of the extracts. This study could help better utilize L. japonica flower buds as a readily accessible source of natural antioxidants in food and pharmaceutical industries. Copyright © 2015 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

A new blood vessel extraction technique using edge enhancement and object classification.

PubMed

Badsha, Shahriar; Reza, Ahmed Wasif; Tan, Kim Geok; Dimyati, Kaharudin

2013-12-01

Diabetic retinopathy (DR) is increasing progressively pushing the demand of automatic extraction and classification of severity of diseases. Blood vessel extraction from the fundus image is a vital and challenging task. Therefore, this paper presents a new, computationally simple, and automatic method to extract the retinal blood vessel. The proposed method comprises several basic image processing techniques, namely edge enhancement by standard template, noise removal, thresholding, morphological operation, and object classification. The proposed method has been tested on a set of retinal images. The retinal images were collected from the DRIVE database and we have employed robust performance analysis to evaluate the accuracy. The results obtained from this study reveal that the proposed method offers an average accuracy of about 97 %, sensitivity of 99 %, specificity of 86 %, and predictive value of 98 %, which is superior to various well-known techniques.

Quantitative determination of 5-hydroxy-N-methylpyrrolidone in urine for biological monitoring of N-methylpyrrolidone exposure.

PubMed

Ligocka, D; Lison, D; Haufroid, V

2002-10-05

The aim of this work was to validate a sensitive method for quantitative analysis of 5-hydroxy-N-methylpyrrolidone (5-HNMP) in urine. This compound has been recommended as a marker for biological monitoring of N-methylpyrrolidone (NMP) exposure. Different solvents and alternative methods of extraction including liquid-liquid extraction (LLE) on Chem Elut and solid-phase extraction (SPE) on Oasis HLB columns were tested. The most efficient extraction of 5-HNMP in urine was LLE with Chem Elut columns and dichloromethane as a solvent (consistently 22% of recovery). The urinary extracts were derivatized by bis(trimethylsilyl)trifluoroacetamide and analysed by gas chromatography-mass spectrometry (GC-MS) with tetradeutered 5-HNMP as an internal standard. The detection limit of this method is 0.017 mg/l urine with an intraassay precision of 1.6-2.6%. The proposed method of extraction is simple and reproducible. Four different m/z signal ratios of TMS-5-HNMP and tetralabelled TMS-5-HNMP have been validated and could be indifferently used in case of unexpected impurities from urine matrix. Copyright 2002 Elsevier Science B.V.

Determination of 15 polycyclic aromatic hydrocarbons in aquatic products by solid-phase extraction and GC-MS.

PubMed

Liu, Qiying; Guo, Yuanming; Sun, Xiumei; Hao, Qing; Cheng, Xin; Zhang, Lu

2018-02-22

We propose a method for the simultaneous determination of 15 kinds of polycyclic aromatic hydrocarbons in marine samples (muscle) employing gas chromatography with mass spectrometry after saponification with ultrasound-assisted extraction and solid-phase extraction. The experimental conditions were optimized by the response surface method. In addition, the effects of different lyes and extractants on polycyclic aromatic hydrocarbons extraction were discussed, and saturated sodium carbonate was first used as the primary saponification reaction and extracted with 10 mL of ethyl acetate and secondly 1 mol/L of sodium hydroxide and 10 mL of n-hexane were used to achieve better results. The average recovery was 67-112%. Satisfactory data showed that the method has good reproducibility with a relative standard deviation of <13%. The detection limits of polycyclic aromatic hydrocarbons were 0.02-0.13 ng/g. Compared with other methods, this method has the advantages of simple pretreatment, low solvent consumption, maximum polycyclic aromatic hydrocarbons extraction, the fast separation speed, and the high extraction efficiency. It is concluded that this method meets the batch processing requirements of the sample and can also be used to determine polycyclic aromatic hydrocarbons in other high-fat (fish, shrimp, crab, shellfish) biological samples. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

One-calibrant kinetic calibration for on-site water sampling with solid-phase microextraction.

PubMed

Ouyang, Gangfeng; Cui, Shufen; Qin, Zhipei; Pawliszyn, Janusz

2009-07-15

The existing solid-phase microextraction (SPME) kinetic calibration technique, using the desorption of the preloaded standards to calibrate the extraction of the analytes, requires that the physicochemical properties of the standard should be similar to those of the analyte, which limited the application of the technique. In this study, a new method, termed the one-calibrant kinetic calibration technique, which can use the desorption of a single standard to calibrate all extracted analytes, was proposed. The theoretical considerations were validated by passive water sampling in laboratory and rapid water sampling in the field. To mimic the variety of the environment, such as temperature, turbulence, and the concentration of the analytes, the flow-through system for the generation of standard aqueous polycyclic aromatic hydrocarbons (PAHs) solution was modified. The experimental results of the passive samplings in the flow-through system illustrated that the effect of the environmental variables was successfully compensated with the kinetic calibration technique, and all extracted analytes can be calibrated through the desorption of a single calibrant. On-site water sampling with rotated SPME fibers also illustrated the feasibility of the new technique for rapid on-site sampling of hydrophobic organic pollutants in water. This technique will accelerate the application of the kinetic calibration method and also will be useful for other microextraction techniques.

Matrix effect and recovery terminology issues in regulated drug bioanalysis.

PubMed

Huang, Yong; Shi, Robert; Gee, Winnie; Bonderud, Richard

2012-02-01

Understanding the meaning of the terms used in the bioanalytical method validation guidance is essential for practitioners to implement best practice. However, terms that have several meanings or that have different interpretations exist within bioanalysis, and this may give rise to differing practices. In this perspective we discuss an important but often confusing term - 'matrix effect (ME)' - in regulated drug bioanalysis. The ME can be interpreted as either the ionization change or the measurement bias of the method caused by the nonanalyte matrix. The ME definition dilemma makes its evaluation challenging. The matrix factor is currently used as a standard method for evaluation of ionization changes caused by the matrix in MS-based methods. Standard additions to pre-extraction samples have been suggested to evaluate the overall effects of a matrix from different sources on the analytical system, because it covers ionization variation and extraction recovery variation. We also provide our personal views on the term 'recovery'.

Evaluation of Antinociceptive Activity of Aqueous Extract of Bark of Psidium Guajava in Albino Rats and Albino Mice

PubMed Central

Jayasree, T.; Ubedulla, Shaikh; Dixit, Rohit; V S, Manohar; J, Shankar

2014-01-01

Background: Psidium guajava is commonly known as guava. Psidium guajava is a medium sized tree belonging to the family Myrtaceae found throughout the tropics. All the parts of the plant, the leaves, followed by the fruits, bark and the roots are used in traditional medicine. The traditional uses of the plant are Antidiarrheal, Antimicrobial Activity, Antimalarial/Antiparasitic Activity, Antitussive and antihyperglycaemic. Leaves are used as Anti-inflammatory, Analgesic and Antinociceptive effects. Aim: To evaluate the antinociceptive activity of aqueous extract of bark of Psidium guajava in albino rats with that of control and standard analgesic drugs aspirin and tramadol. Materials and Methods: Mechanical (Tail clip method) and thermal (Tail flick method using Analgesiometer), 0.6% solution of acetic acid writhing models of nociception were used to evaluate the extract antinociceptive activity. Six groups of animals, each consists of 10 animals, first one as control, second and third as standard drugs, Aspirin and Tramadol, fourth, fifth and sixth groups as text received the extract (100, 200, and 400 mg/ kg) orally 60 min prior to subjection to the respective test. Results: The results obtained demonstrated that aqueous extract of bark of Psidium guajava produced significant antinociceptive response in all the mechanical and thermal-induced nociception models. Conclusion: AEPG antinociceptive activity involves activation of the peripheral and central mechanisms. PMID:25386462

Detection of Chlorogenic Acid in Honeysuckle Using Infrared-Assisted Extraction Followed by Capillary Electrophoresis with UV Detector

PubMed Central

Tang, Zhuxing; Zang, Shuliang; Zhang, Xiangmin

2012-01-01

In this study, a novel infrared-assisted extraction method coupled capillary electrophoresis (CE) is employed to determine chlorogenic acid from a traditional Chinese medicine (TCM), honeysuckle. The effects of pH and the concentration of the running buffer, separation voltage, injection time, IR irradiation time, and anhydrous ethanol in the extraction concentration were investigated. The optimal conditions were as follows: extraction time, 30 min; extraction solvent, 80% (v/v) ethanol in water solution; and 50 mmol/L borate buffer (pH 8.7) was used as the running buffer at a separation voltage of 16 kV. The samples were injected electrokinetically at 16 kV for 8 s. Good linearity (r2 > 0.9996) was observed over the concentration ranges investigated, and the stability of the solutions was high. Recoveries of the chlorogenic acid were from 95.53% to 106.62%, and the relative standard deviation was below 4.1%. By using this novel IR-assisted extraction method, a higher extraction efficiency than those extracted with conventional heat-reflux extraction was found. The developed IR-assisted extraction method is simple, low-cost, and efficient, offering a great promise for the quick determination of active compounds in TCM. The results indicated that IR-assisted extraction followed by CE is a reliable method for quantitative analysis of active ingredient in TCM. PMID:22291060

Rapid extraction from and direct identification in clinical samples of methicillin-resistant staphylococci using the PCR.

PubMed

Jaffe, R I; Lane, J D; Albury, S V; Niemeyer, D M

2000-09-01

Methicillin-resistant staphylococci (MRS) are one of the most common causes of nosocomial infections and bacteremia. Standard bacterial identification and susceptibility testing frequently require as long as 72 h to report results, and there may be difficulty in rapidly and accurately identifying methicillin resistance. The use of the PCR is a rapid and simple process for the amplification of target DNA sequences, which can be used to identify and test bacteria for antimicrobial resistance. However, many sample preparation methods are unsuitable for PCR utilization in the clinical laboratory because they either are not cost-effective, take too long to perform, or do not provide a satisfactory DNA template for PCR. Our goal was to provide same-day results to facilitate rapid diagnosis and therapy. In this report, we describe a rapid method for extraction of bacterial DNA directly from blood culture bottles that gave quality DNA for PCR in as little as 20 min. We compared this extraction method to the standard QIAGEN method for turnaround time (TAT), cost, purity, and use of template in PCR. Specific identification of MRS was determined using intragenic primer sets for bacterial and Staphylococcus 16S rRNA and mecA gene sequences. The PCR primer sets were validated with 416 isolates of staphylococci, including methicillin-resistant Staphylococcus aureus (n = 106), methicillin-sensitive S. aureus (n = 134), and coagulase-negative Staphylococcus (n = 176). The total supply cost of our extraction method and PCR was $2.15 per sample with a result TAT of less than 4 h. The methods described herein represent a rapid and accurate DNA extraction and PCR-based identification system, which makes the system an ideal candidate for use under austere field conditions and one that may have utility in the clinical laboratory.

Flavanoid biocides: Wood preservatives based on condensed tannins

Treesearch

Peter Laks; Peggy A. McKaig; Richard W. Hemingway

1988-01-01

The condensed tannins are natural wood preservatives found in high concentrations in the bark and wood of some tree species. Condensed tannin-containing bark extracts from loblolly pine (Pinus taeda) were evaluated as wood preservatives using standard methods. Bark extracts by themselves did not cause any reduction in weight loss of pressure-treated...

[Determination of β-sitosterol and total sterols content and antioxidant activity of oil in acai (Euterpe oleracea)].

PubMed

He, Cheng; Li, Wei; Zhang, Jian-Jun; Qu, Sheng-Sheng; Li, Jia-Jing; Wang, Lin-Yuan

2014-12-01

In order to establish a method for the determination of the sterols of the oil in the freeze-dried acai (Euterpe oleracea Mart.) and to evaluate its antioxidant activities, a saponification/extraction procedure and high performance liquid chromatography (HPLC) analysis method were developed and validated for the analysis of phytosterols in PEE (Petroleum ether extract). Separation was achieved on a Purosper STAR LP C18 column with a binary, gradient solvent system of acetonitrile and isopropanol. Evaporative light scattering detection (ELSD) was used to quantify β-sitosterol and the total sterols. Peak identification was verified by retention times and spikes with external standards. Standard curves were constructed (r = 0.999 2) to allow for sample quantification. Recovery of the saponification and extraction was demonstrated via analysis of spiked samples. The highest content of total sterols is β-sitosterol. The antioxidant activities of the extracts were evaluated using the total oxyradical scavenging capacity assay (TOSC assay). The result showed that the PEE exhibited significant antioxidant properties, sample concentration and the antioxidant capacity had a certain relevance.

Rapid determination of protopine, allocryptopine, sanguinarine and chelerythrine in fruits of Macleaya cordata by microwave-assisted solvent extraction and HPLC-ESI/MS.

PubMed

Luo, Xu-Biao; Chen, Bo; Yao, Shou-Zhuo

2006-01-01

An isocratic high-performance liquid chromatographic method coupled with electrospray mass spectrometry was developed to determine protopine, allocryptopine, sanguinarine and chelerythrine in fruits of Macleaya cordata. The sample was extracted with hydrochloric acid aqueous solution using microwave-assisted extraction method. The extracts were separated on a C8 reversed-phase HPLC column with acetonitrile:acetate buffer as mobile phase, and full elution of all analytes was realized isocratically within 10 min. The abundance of pseudomolecule ions was recorded using selected ion recording at m/z 354.4, 370.1, 332.5, 348.5 and 338.5 for protopine, allocryptopine, sanguinarine, chelerythrine and the internal standard, jatrorrhizine, respectively. Internal standard curves were used for the quantification of protopine, allocryptopine, sanguinarine and chelerythrine, which showed a linear range of 0.745-74.5, 0.610-61.0, 0.525-105 and 0.375-75 microg/mL, respectively, with correlation coefficients of 0.9995, 0.9992, 0.9993 and 0.9989, and limits of detection of 3.73, 3.05, 1.60 and 1.11 ng/mL, respectively.

Joint recognition and discrimination in nonlinear feature space

NASA Astrophysics Data System (ADS)

Talukder, Ashit; Casasent, David P.

1997-09-01

A new general method for linear and nonlinear feature extraction is presented. It is novel since it provides both representation and discrimination while most other methods are concerned with only one of these issues. We call this approach the maximum representation and discrimination feature (MRDF) method and show that the Bayes classifier and the Karhunen- Loeve transform are special cases of it. We refer to our nonlinear feature extraction technique as nonlinear eigen- feature extraction. It is new since it has a closed-form solution and produces nonlinear decision surfaces with higher rank than do iterative methods. Results on synthetic databases are shown and compared with results from standard Fukunaga- Koontz transform and Fisher discriminant function methods. The method is also applied to an automated product inspection problem (discrimination) and to the classification and pose estimation of two similar objects (representation and discrimination).

Synergetic Antimicrobial Effects of Mixtures of Ethiopian Honeys and Ginger Powder Extracts on Standard and Resistant Clinical Bacteria Isolates

PubMed Central

Ewnetu, Yalemwork; Lemma, Wossenseged; Birhane, Nega

2014-01-01

Purpose. To evaluate antimicrobial effects of mixtures of Ethiopian honeys and ginger rhizome powder extracts on Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), Staphylococcus aureus (MRSA), Escherichia coli (R), and Klebsiella pneumoniae (R). Methods. Agar diffusion and broth assays were performed to determine susceptibility of these standard and resistant clinical bacteria isolates using honey-ginger powder extract mixtures. Results. Honey-ginger powder extract mixtures produced the highest mean inhibition (25.62 mm ± 2.55) compared to the use of honeys (21.63 mm ± 3.30) or ginger extracts (19.23 mm ± 3.42) individually. The ranges of inhibitions produced by honey-ginger extract mixtures on susceptible test organisms (26–30 mm) and resistant strains (range: 19–27 mm) were higher compared to 7–22 mm and 0–14 mm by standard antibiotic discs. Minimum inhibitory concentrations (MIC) of mixture of honeys-ginger extracts were 6.25% (0.625 v/mL) on the susceptible bacteria compared to 75% for resistant clinical isolates. Minimum bactericidal concentration (MBC) of honey-ginger extracts was 12.5% (0.125 g/mL) for all the test organisms. Conclusion. The result of this study showed that honey-ginger powder extract mixtures have the potential to serve as cheap source of antibacterial agents especially for the drug resistant bacteria strains. PMID:24772182

Pressurized liquid extraction of diesel and air particulate standard reference materials: effect of extraction temperature and pressure.

PubMed

Schantz, Michele M; McGaw, Elizabeth; Wise, Stephen A

2012-10-02

Four particulate matter Standard Reference Materials (SRMs) available from the National Institute of Standards and Technology (NIST) were used to evaluate the effect of solvent, number of static cycles and static times, pressure, and temperature when using pressurized liquid extraction (PLE) for the extraction of polycyclic aromatic hydrocarbons (PAHs) and nitrated-PAHs. The four materials used in the study were SRM 1648a Urban Particulate Matter, SRM 1649b Urban Dust, SRM 1650b Diesel Particulate Matter, and SRM 2975 Diesel Particulate Matter (Industrial Forklift). The results from the study indicate that the choice of solvent, dichloromethane compared to toluene and toluene/methanol mixtures, had little effect on the extraction efficiency. With three to five extraction cycles, increasing the extraction time for each cycle from 5 to 30 min had no significant effect on the extraction efficiency. The differences in extraction efficiency were not significant (with over 95% of the differences being <10%) when the pressure was increased from 13.8 to 20.7 MPa. The largest increase in extraction efficiency occurred for selected PAHs when the temperature of extraction was increased from 100 to 200 °C. At 200 °C naphthalene, biphenyl, fluorene, dibenzothiophene, and anthracene show substantially higher mass fractions (>30%) than when extracted at 100 °C in all the SRMs studied. For SRM 2975, large increases (>100%) are also observed for some other PAHs including benz[a]anthracene, benzo[k]fluoranthene, benzo[e]pyrene, benzo[a]pyrene, benzo[ghi]perylene, and benzo[b]chrysene when extracted at the higher temperatures; however, similar trends were not observed for the other diesel particulate sample, SRM 1650b. The results are discussed in relation to the use of the SRMs for evaluating analytical methods.

Accelerated, microwave-assisted, and conventional solvent extraction methods affect anthocyanin composition from colored grains.

PubMed

Abdel-Aal, El-Sayed M; Akhtar, Humayoun; Rabalski, Iwona; Bryan, Michael

2014-02-01

Anthocyanins are important dietary components with diverse positive functions in human health. This study investigates effects of accelerated solvent extraction (ASE) and microwave-assisted extraction (MAE) on anthocyanin composition and extraction efficiency from blue wheat, purple corn, and black rice in comparison with the commonly used solvent extraction (CSE). Factorial experimental design was employed to study effects of ASE and MAE variables, and anthocyanin extracts were analyzed by spectrophotometry, high-performance liquid chromatography-diode array detector (DAD), and liquid chromatography-mass spectrometry chromatography. The extraction efficiency of ASE and MAE was comparable with CSE at the optimal conditions. The greatest extraction by ASE was achieved at 50 °C, 2500 psi, 10 min using 5 cycles, and 100% flush. For MAE, a combination of 70 °C, 300 W, and 10 min in MAE was the most effective in extracting anthocyanins from blue wheat and purple corn compared with 50 °C, 1200 W, and 20 min for black rice. The anthocyanin composition of grain extracts was influenced by the extraction method. The ASE extraction method seems to be more appropriate in extracting anthocyanins from the colored grains as being comparable with the CSE method based on changes in anthocyanin composition. The method caused lower structural changes in anthocaynins compared with the MAE method. Changes in blue wheat anthocyanins were lower in comparison with purple corn or black rice perhaps due to the absence of acylated anthocyanin compounds in blue wheat. The results show significant differences in anthocyanins among the 3 extraction methods, which indicate a need to standardize a method for valid comparisons among studies and for quality assurance purposes. © 2014 Her Majesty the Queen in Right of Canada Journal of Food Science © 2014 Institute of Food Technologists® Reproduced with the permission of the Minister of Agriculture and Agri-Food Canada.

Polytetrafluorethylene film-based liquid-three phase micro extraction coupled with differential pulse voltammetry for the determination of atorvastatin calcium.

PubMed

Ensafi, Ali A; Khoddami, Elaheh; Rezaei, Behzad

2013-01-01

In this paper, we describe a new combination method based on polytetrafluorethylene (PTFE) film-based liquid three-phase micro extraction coupled with differential pulse voltammetry (DPV) for the micro extraction and quantification of atorvastatin calcium (ATC) at the ultra-trace level. Different factors affecting the liquid-three phases micro extraction of atorvastatin calcium, including organic solvent, pH of the donor and acceptor phases, concentration of salt, extraction time, stirring rate and electrochemical factors, were investigated, and the optimal extraction conditions were established. The final stable signal was achieved after a 50 min extraction time, which was used for analytical applications. An enrichment factor of 21 was achieved, and the relative standard deviation (RSD) of the method was 4.5% (n = 4). Differential pulse voltammetry exhibited two wide linear dynamic ranges of 20.0-1000.0 pmol L(-1) and 0.001-11.0 µmol L(-1) of ATC. The detection limit was found to be 8.1 pmol L(-1) ATC. Finally, the proposed method was used as a new combination method for the determination of atorvastatin calcium in real samples, such as human urine and plasma.

Analysis of phytochemical profile of Terminalia arjuna bark extract with antioxidative and antimicrobial properties

PubMed Central

Mandal, Shreya; Patra, Arpita; Samanta, Animesh; Roy, Suchismita; Mandal, Arpita; Mahapatra, Tapasi Das; Pradhan, Shrabani; Das, Koushik; Nandi, Dilip Kumar

2013-01-01

Objective To investigate phytochemical screening, antimicrobial activity and qualitative thin layer chromatographic separation of flavonoid components, antioxidant activity and total flavonoid compound of Terminalia arjuna. Methods For phytochemical screening, some common and available standard tests were done. Antimicrobial bioassay was done through agar well diffusion method. Detection of antioxidant activity and flavonoid compounds were done through thin layer chromatography. Total antioxidant activity was measured by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) in colorimetric method. Aluminum chloride colorimetric method was used for total flavonoid determination. Results Phytochemical screening showed the active compounds presence in high concentration, such as phytosterol, lactones, flavonoids, phenolic compounds and tannins and glycosides. The antimicrobial activity of extract showed that greater inhibition zone against Gram negative bacteria than Gram positive bacteria. This methanolic extract showed a promising antioxidant activity, as absorption of DPPH redicles decreased in DPPH free radical scavenging assay. Flavonoids components having antioxidant property present in the methanol extract at a level of 199.00 mg quercetin equivalent/g of dried methanol extract in colorimetric method. Conclusions The Terminalia arjuna bark extract revealed the presence of bio-active constituents which are known to exhibit medicinal as well as physiological activities. PMID:24093787

Preparation of a novel sorptive stir bar based on vinylpyrrolidone-ethylene glycol dimethacrylate monolithic polymer for the simultaneous extraction of diazepam and nordazepam from human plasma.

PubMed

Torabizadeh, Mahsa; Talebpour, Zahra; Adib, Nuoshin; Aboul-Enein, Hassan Y

2016-04-01

A new monolithic coating based on vinylpyrrolidone-ethylene glycol dimethacrylate polymer was introduced for stir bar sorptive extraction. The polymerization step was performed using different contents of monomer, cross-linker and porogenic solvent, and the best formulation was selected. The quality of the prepared vinylpyrrolidone-ethylene glycol dimethacrylate stir bars was satisfactory, demonstrating good repeatability within batch (relative standard deviation < 3.5%) and acceptable reproducibility between batches (relative standard deviation < 6.0%). The prepared stir bar was utilized in combination with ultrasound-assisted liquid desorption, followed by high-performance liquid chromatography with ultraviolet detection for the simultaneous determination of diazepam and nordazepam in human plasma samples. To optimize the extraction step, a three-level, four-factor, three-block Box-Behnken design was applied. Under the optimum conditions, the analytical performance of the proposed method displayed excellent linear dynamic ranges for diazepam (36-1200 ng/mL) and nordazepam (25-1200 ng/mL), with correlation coefficients of 0.9986 and 0.9968 and detection limits of 12 and 10 ng/mL, respectively. The intra- and interday recovery ranged from 93 to 106%, and the relative standard deviations were less than 6%. Finally, the proposed method was successfully applied to the analysis of diazepam and nordazepam at their therapeutic levels in human plasma. The novelty of this study is the improved polarity of the stir bar coating and its application for the simultaneous extraction of diazepam and its active metabolite, nordazepam in human plasma sample. The method was more rapid than previously reported stir bar sorptive extraction techniques based on monolithic coatings, and exhibited lower detection limits in comparison with similar methods for the determination of diazepam and nordazepam in biological fluids. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Improved efficiency of extraction of polycyclic aromatic hydrocarbons (PAHs) from the National Institute of Standards and Technology (NIST) Standard Reference Material Diesel Particulate Matter (SRM 2975) using accelerated solvent extraction.

PubMed

Masala, Silvia; Ahmed, Trifa; Bergvall, Christoffer; Westerholm, Roger

2011-12-01

The efficiency of extraction of polycyclic aromatic hydrocarbons (PAHs) with molecular masses of 252, 276, 278, 300, and 302 Da from standard reference material diesel particulate matter (SRM 2975) has been investigated using accelerated solvent extraction (ASE) with dichloromethane, toluene, methanol, and mixtures of toluene and methanol. Extraction of SRM 2975 using toluene/methanol (9:1, v/v) at maximum instrumental settings (200 °C, 20.7 MPa, and five extraction cycles) with 30-min extraction times resulted in the following elevations of the measured concentration when compared with the certified and reference concentrations reported by the National Institute of Standards and Technology (NIST): benzo[b]fluoranthene, 46%; benzo[k]fluoranthene, 137%; benzo[e]pyrene, 103%; benzo[a]pyrene, 1,570%; perylene, 37%; indeno[1,2,3-cd]pyrene, 41%; benzo[ghi]perylene, 163%; and coronene, 361%. The concentrations of the following PAHs were comparable to the reference values assigned by NIST: indeno[1,2,3-cd]fluoranthene, dibenz[a,h]anthracene, and picene. The measured concentration of dibenzo[a,e]-pyrene was lower than the information value reported by the NIST. The measured concentrations of other highly carcinogenic PAHs (dibenzo[a,l]pyrene, dibenzo[a,i]pyrene, and dibenzo[a,h]pyrene) in SRM 2975 are also reported. Comparison of measurements using the optimized ASE method and using similar conditions to those applied by the NIST for the assignment of PAH concentrations in SRM 2975 indicated that the higher values obtained in the present study were associated with more complete extraction of PAHs from the diesel particulate material. Re-extraction of the particulate samples demonstrated that the deuterated internal standards were more readily recovered than the native PAHs, which may explain the lower values reported by the NIST. The analytical results obtained in the study demonstrated that the efficient extraction of PAHs from SRM 2975 is a critical requirement for the accurate determination of PAHs with high molecular masses in this standard reference material and that the optimization of extraction conditions is essential to avoid underestimation of the PAH concentrations. The requirement is especially relevant to the human carcinogen benzo[a]pyrene, which is commonly used as an indicator of the carcinogenic risk presented by PAH mixtures.

Methodological Considerations for Hair Cortisol Measurements in Children

PubMed Central

Slominski, Radomir; Rovnaghi, Cynthia R.; Anand, Kanwaljeet J. S.

2015-01-01

Background Hair cortisol levels are used increasingly as a measure for chronic stress in young children. We propose modifications to the current methods used for hair cortisol analysis to more accurately determine reference ranges for hair cortisol across different populations and age groups. Methods The authors compared standard (finely cutting hair) vs. milled methods for hair processing (n=16), developed a 4-step extraction process for hair protein and cortisol (n=16), and compared liquid chromatography-mass spectrometry (LCMS) vs. ELISA assays for measuring hair cortisol (n=28). The extraction process included sequential incubations in methanol and acetone, repeated twice. Hair protein was measured via spectrophotometric ratios at 260/280 nm to indicate the hair dissolution state using a BioTek® plate reader and dedicated software. Hair cortisol was measured using an ELISA assay kit. Individual (n=13), pooled hair samples (n=12) with high, intermediate, and low cortisol values and the ELISA assay internal standards (n=3) were also evaluated by LCMS. Results Milled and standard methods showed highly correlated hair cortisol (rs=0.951, p<0.0001) and protein values (rs=0.902, p=0.0002), although higher yields of cortisol and protein were obtained from the standard method in 13/16 and 14/16 samples respectively (p<0.05). Four sequential extractions yielded additional amounts of protein (36.5%, 27.5%, 30.5%, 3.1%) and cortisol (45.4%, 31.1%, 15.1%, 0.04%) from hair samples. Cortisol values measured by LCMS and ELISA were correlated (rs=0.737; p<0.0001), although cortisol levels (median [IQR]) detected in the same samples by LCMS (38.7 [14.4, 136] ng/ml) were lower than by ELISA (172.2 [67.9, 1051] ng/ml). LCMS also detected cortisone, which comprised 13.4% (3.7%, 25.9%) of the steroids detected. Conclusion Methodological studies suggest that finely cutting hair with sequential incubations in methanol and acetone, repeated twice, extracts greater yields of cortisol than does milled hair. Based on these findings, at least three incubations may be required to extract most of the cortisol in human hair samples. In addition, ELISA-based assays showed greater sensitivity for measuring hair cortisol levels than LCMS-based assays. PMID:25811341

A solid phase extraction-liquid chromatographic-tandem mass spectrometry method for determination of concentrations of GDC-0941, a small molecule class I phosphatidylinositide 3-kinase inhibitor, to support clinical development.

PubMed

Ding, X; Morrison, G; Dean, B; Hop, C E C A; Tobler, L; Percey, S; Meng, M; Reuschel, S; West, D A; Holden, S; Ware, J A

2012-03-05

A solid phase extraction (SPE) liquid chromatographic-tandem mass spectrometry (LC-MS/MS) method for the determination of GDC-0941 concentrations in human plasma has been developed and validated to support clinical development. An Oasis MCX 10mg 96-well SPE plate was used to extract plasma samples (50 μL) and the resulting extracts were analyzed using reverse-phase chromatography and mass spectrometer coupled with a turbo-ionspray interface. The method was validated over the calibration curve range 0.500-500 ng/mL with linear regression and 1/x(2) weighting. Within-run relative standard deviation (%RSD) ranged from 1.5 to 11.5%, while the between-run %RSD varied from 0.0 to 4.4%. The accuracy ranged from 96.0% to 110.0% of nominal for within-run and 98.0% to 108.0% of nominal for between-run at all concentrations including the LLOQ quality control at 0.500 ng/mL. Extraction recovery of GDC-0941 was between 79.0% and 86.2%. Stability of GDC-0941 was established in human plasma for 602 days at -70 °C and 598 days at -20°C, respectively, and established in reconstituted sample extracts for 167 h when stored at room temperature. Internal standard normalized matrix factor was 1.1, demonstrating that the use of the stable-labeled internal standard GDC-0941-d(8) effectively compensated observed matrix effect and resulting in no adverse impact on the quality of the data produced. This assay was used for the determination of GDC-0941 human plasma concentrations over a sufficient time period to determine pharmacokinetic parameters at relevant clinical doses. Copyright © 2011 Elsevier B.V. All rights reserved.

Effect of Catechins, Green tea Extract and Methylxanthines in Combination with Gentamicin Against Staphylococcus aureus and Pseudomonas aeruginosa

PubMed Central

Fazly Bazzaz, Bibi Sedigheh; Sarabandi, Sahar; Khameneh, Bahman; Hosseinzadeh, Hossein

2016-01-01

Objectives: Bacterial resistant infections have become a global health challenge and threaten the society’s health. Thus, an urgent need exists to find ways to combat resistant pathogens. One promising approach to overcoming bacterial resistance is the use of herbal products. Green tea catechins, the major green tea polyphenols, show antimicrobial activity against resistant pathogens. The present study aimed to investigate the effect of catechins, green tea extract, and methylxanthines in combination with gentamicin against standard and clinical isolates of Staphylococcus aureus (S. aureus) and the standard strain of Pseudomonas aeruginosa (P. aeruginosa). Methods: The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) values of different agents against bacterial strains were determined. The interactions of green tea extract, epigallate catechin, epigallocatechin gallate, two types of methylxanthine, caffeine, and theophylline with gentamicin were studied in vitro by using a checkerboard method and calculating the fraction inhibitory concentration index (FICI). Results: The MICs of gentamicin against bacterial strains were in the range of 0.312 - 320 μg/mL. The MIC values of both types of catechins were 62.5 - 250 μg/ mL. Green tea extract showed insufficient antibacterial activity when used alone. Methylxanthines had no intrinsic inhibitory activity against any of the bacterial strains tested. When green tea extract and catechins were combined with gentamicin, the MIC values of gentamicin against the standard strains and a clinical isolate were reduced, and synergistic activities were observed (FICI < 1). A combination of caffeine with gentamicin did not alter the MIC values of gentamicin. Conclusion: The results of the present study revealed that green tea extract and catechins potentiated the antimicrobial action of gentamicin against some clinical isolates of S. aureus and standard P. aeruginosa strains. Therefore, combinations of gentamicin with these natural compounds might be a promising approach to combat microbial resistance. PMID:28097041

Semantic information extracting system for classification of radiological reports in radiology information system (RIS)

NASA Astrophysics Data System (ADS)

Shi, Liehang; Ling, Tonghui; Zhang, Jianguo

2016-03-01

Radiologists currently use a variety of terminologies and standards in most hospitals in China, and even there are multiple terminologies being used for different sections in one department. In this presentation, we introduce a medical semantic comprehension system (MedSCS) to extract semantic information about clinical findings and conclusion from free text radiology reports so that the reports can be classified correctly based on medical terms indexing standards such as Radlex or SONMED-CT. Our system (MedSCS) is based on both rule-based methods and statistics-based methods which improve the performance and the scalability of MedSCS. In order to evaluate the over all of the system and measure the accuracy of the outcomes, we developed computation methods to calculate the parameters of precision rate, recall rate, F-score and exact confidence interval.

Establishment of Application Guidance for OTC non-Kampo Crude Drug Extract Products in Japan

PubMed Central

Somekawa, Layla; Maegawa, Hikoichiro; Tsukada, Shinsuke; Nakamura, Takatoshi

2017-01-01

Currently, there are no standardized regulatory systems for herbal medicinal products worldwide. Communication and sharing of knowledge between different regulatory systems will lead to mutual understanding and might help identify topics which deserve further discussion in the establishment of common standards. Regulatory information on traditional herbal medicinal products in Japan is updated by the establishment of Application Guidance for over-the-counter non-Kampo Crude Drug Extract Products. We would like to report on updated regulatory information on the new Application Guidance. Methods for comparison of Crude Drug Extract formulation and standard decoction and criteria for application and the key points to consider for each criterion are indicated in the guidance. Establishment of the guidance contributes to improvements in public health. We hope that the regulatory information about traditional herbal medicinal products in Japan will be of contribution to tackling the challenging task of regulating traditional herbal products worldwide. PMID:28894633

Absolute quantitation of intracellular metabolite concentrations by an isotope ratio-based approach

PubMed Central

Bennett, Bryson D; Yuan, Jie; Kimball, Elizabeth H; Rabinowitz, Joshua D

2009-01-01

This protocol provides a method for quantitating the intracellular concentrations of endogenous metabolites in cultured cells. The cells are grown in stable isotope-labeled media to near-complete isotopic enrichment and then extracted in organic solvent containing unlabeled internal standards in known concentrations. The ratio of endogenous metabolite to internal standard in the extract is determined using mass spectrometry (MS). The product of this ratio and the unlabeled standard amount equals the amount of endogenous metabolite present in the cells. The cellular concentration of the metabolite can then be calculated on the basis of intracellular volume of the extracted cells. The protocol is exemplified using Escherichia coli and primary human fibroblasts fed uniformly with 13C-labeled carbon sources, with detection of 13C-assimilation by liquid chromatography–tandem MS. It enables absolute quantitation of several dozen metabolites over ~1 week of work. PMID:18714298

Triaxial- and uniaxial-compression testing methods developed for extraction of pore water from unsaturated tuff, Yucca Mountain, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mower, T.E.; Higgins, J.D.; Yang, I.C.

1989-12-31

To support the study of hydrologic system in the unsaturated zone at Yucca Mountain, Nevada, two extraction methods were examined to obtain representative, uncontaminated pore-water samples from unsaturated tuff. Results indicate that triaxial compression, which uses a standard cell, can remove pore water from nonwelded tuff that has an initial moisture content greater than 11% by weight; uniaxial compression, which uses a specifically fabricated cell, can extract pore water from nonwelded tuff that has an initial moisture content greater than 8% and from welded tuff that has an initial moisture content greater than 6.5%. For the ambient moisture conditions ofmore » Yucca Mountain tuffs, uniaxial compression is the most efficient method of pore-water extraction. 12 refs., 7 figs., 2 tabs.« less

Extraction, characterization and biological studies of phytochemicals from Mammea suriga.

PubMed

Poojary, Mahesha M; Vishnumurthy, Kanivebagilu A; Vasudeva Adhikari, Airody

2015-06-01

The present work involves extraction of phytochemicals from the root bark of a well-known Indian traditional medicinal plant, viz. Mammea suriga , with various solvents and evaluation of their in vitro antimicrobial and antioxidant activities using standard methods. The phytochemical analysis indicates the presence of some interesting secondary metabolites like flavonoids, cardiac glycosides, alkaloids, saponins and tannins in the extracts. Also, the solvent extracts displayed promising antimicrobial activity against Staphylococcus aureus , Bacillus subtilis and Cryptococcus neoformans with inhibition zone in a range of 20-33 mm. Further, results of their antioxidant screening revealed that aqueous extract (with IC 50 values of 111.51±1.03 and 31.05±0.92 μg/mL in total reducing power assay and DPHH radical scavenging assay, respectively) and ethanolic extract (with IC 50 values of 128.00±1.01 and 33.25±0.89 μg/mL in total reducing power assay and DPHH radical scavenging assay, respectively) were better antioxidants than standard ascorbic acid. Interestingly, FT-IR analysis of each extract established the presence of various biologically active functional groups in it.

A new method of UA_CPE coupled with spectrophotometry for the faster and cost-effective detection of proline in fruit juice, honey, and wine.

PubMed

Dağdeviren, Semahat; Altunay, Nail; Sayman, Yasin; Gürkan, Ramazan

2018-07-30

The study developed a new method for proline detection in honey, wine and fruit juice using ultrasound assisted-cloud point extraction (UA-CPE) and spectrophotometry. Initially, a quaternary complex was built, containing proline, histamine, Cu(II), and fluorescein at pH 5.5. Samples were treated with ethanol-water mixture before extraction and preconcentration, using an ultrasonic bath for 10 min at 40 °C (40 kHz, 300 W). After the optimization of variables affecting extraction efficiency, good linearity was obtained between 15 and 600 µg L -1 with sensitivity enhancement factor of 105. The limits of detection and quantification were 5.7 and 19.0 µg L -1 , respectively. The recovery percentage and relative standard deviations (RSD %) were between 95.3 and 103.3%, and 2.5 and 4.2%, respectively. The accuracy of the method was verified by the analysis of a standard reference material (SRM 2389a). Copyright © 2018 Elsevier Ltd. All rights reserved.

Validation of lipolysis product extraction from aqueous/biological samples, separation and quantification by thin-layer chromatography with flame ionization detection analysis using O-cholesteryl ethylene glycol as a new internal standard.

PubMed

Cavalier, Jean-François; Lafont, Dominique; Boullanger, Paul; Houisse, David; Giallo, Jacqueline; Ballester, Jean-Michel; Carrière, Frédéric

2009-09-11

A general and easily accessible method for the extraction followed by the simultaneous separation and quantitative determination of triacylglycerols, diacylglycerols, monoacylglycerols and free fatty acids has been improved and optimized based on existing protocols using liquid-phase extraction and thin-layer chromatography coupled to flame ionization detection (TLC/FID Iatroscan). After lipid extraction in the presence of a suitable new synthetic internal standard, namely CholE1, a single elution step using n-heptane/diethyl ether/formic acid (55:45:1, v/v/v) was applied. This method was validated in line with international bioanalytical method validation guidelines using two different matrix systems: purified water and human gastro-intestinal fluid. Overall, the assay was found to have high levels of precision with coefficients of variation ranging from 1.48% to 11.0% and accuracy ranging from -13.3% to +5.79% RE. The confidence limits of the lipid mean recovery rates varied between 89.9% and 104%. This method is therefore highly suitable for quantifying the lipolysis products generated in vitro during the hydrolysis of various fats and oils by digestive lipases, as well as those collected from the gastro-intestinal tract in the course of human clinical studies on lipid digestion.

Determination of major aromatic constituents in vanilla using an on-line supercritical fluid extraction coupled with supercritical fluid chromatography.

PubMed

Liang, Yanshan; Liu, Jiaqi; Zhong, Qisheng; Shen, Lingling; Yao, Jinting; Huang, Taohong; Zhou, Ting

2018-04-01

An on-line supercritical fluid extraction coupled with supercritical fluid chromatography method was developed for the determination of four major aromatic constituents in vanilla. The parameters of supercritical fluid extraction were systematically investigated using single factor optimization experiments and response surface methodology by a Box-Behnken design. The modifier ratio, split ratio, and the extraction temperature and pressure were the major parameters which have significant effects on the extraction. While the static extraction time, dynamic extraction time, and recycle time had little influence on the compounds with low polarity. Under the optimized conditions, the relative extraction efficiencies of all the constituents reached 89.0-95.1%. The limits of quantification were in the range of 1.123-4.747 μg. The limits of detection were in the range of 0.3368-1.424 μg. The recoveries of the four analytes were in the range of 76.1-88.9%. The relative standard deviations of intra- and interday precision ranged from 4.2 to 7.6%. Compared with other off-line methods, the present method obtained higher extraction yields for all four aromatic constituents. Finally, this method has been applied to the analysis of vanilla from different sources. On the basis of the results, the on-line supercritical fluid extraction-supercritical fluid chromatography method shows great promise in the analysis of aromatic constituents in natural products. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Comparison of macro-gravimetric and micro-colorimetric lipid determination methods.

PubMed

Inouye, Laura S; Lotufo, Guiherme R

2006-10-15

In order to validate a method for lipid analysis of small tissue samples, the standard macro-gravimetric method of Bligh-Dyer (1959) [E.G. Bligh, W.J. Dyer, Can. J. Biochem. Physiol. 37 (1959) 911] and a modification of the micro-colorimetric assay developed by Van Handel (1985) [E. Van Handel, J. Am. Mosq. Control Assoc. 1 (1985) 302] were compared. No significant differences were observed for wet tissues of two species of fish. However, limited analysis of wet tissue of the amphipod, Leptocheirusplumulosus, indicated that the Bligh-Dyer gravimetric method generated higher lipid values, most likely due to the inclusion of non-lipid materials. Additionally, significant differences between the methods were observed with dry tissues, with the micro-colorimetric method consistently reporting calculated lipid values greater than as reported by the gravimetric method. This was most likely due to poor extraction of dry tissue in the standard Bligh-Dyer method, as no significant differences were found when analyzing a single composite extract. The data presented supports the conclusion that the micro-colorimetric method described in this paper is accurate, rapid, and minimizes time and solvent use.

Antimicrobial activity of methanolic extracts of Sambucus ebulus and Urtica dioica against clinical isolates of methicillin resistant Staphylococcus aureus.

PubMed

Salehzadeh, Ali; Asadpour, Leila; Naeemi, Akram Sadat; Houshmand, Elham

2014-01-01

Increase in the emergence of drug -resistant pathogens led to the development of natural antimicrobials. In this study the antimicrobial effect of methanolic extracts of Sambucus ebulus and Urtica dioica on 16 skin and wound infections isolates of methicillin resistant S. aureus have been studied. Solvent extraction procedure was done using soxhlet apparatus for extracting antimicrobial agents from freeze dried plants. Antibacterial activity was measured using agar well diffusion method. The MIC of Sambucus ebulus and Urtica dioica extracts against the standard strain of S. aureus ATCC 6538 were determined using the micro dilution method at 15 mg and 20 mg respectively. All the test bacteria were found sensitive to the Sambucus ebulus extract and only one isolate was resistant to Urtica dioica extract. Extracts of Sambucus ebulus and Urtica dioica possess antibacterial potency against MRSA isolates and may be used as a natural antiseptics and antimicrobial agents in medicine.

A multiresidue method for determination of trace levels of pesticides in air and water.

PubMed

Millet, M; Wortham, H; Sanusi, A; Mirabel, P

1996-11-01

A multiresidue analytical method is described for the analysis of 13 pesticides in fogwater, rainwater, gas, and particles. This method is based upon solid-liquid extraction using Sep-Pak tC18 light cartridges for aqueous samples, soxhlet for gas (adsorbed on XAD-2) and particles (on glass fiber filters), HPLC-based fractionation of the extracted residues using a silica column, and a linear gradient of n-hexane/tert butyl methyl ether followed by GC-ECD and HPLC-UV analyses of each fraction. Prior to analysis with GC-ECD, a methylation procedure using BF3/methanol was developed for the analysis of the fraction which contains chlorophenoxy acid herbicides. The recoveries of the extraction procedure of liquid samples and of the methylation were greater than 92 and 97% with a standard deviation lower than 8 and 5%, respectively. The detection limits varied between 0.1 and 0.01 microgram.ml-1 for the 13 pesticides studied with a standard deviation less than 9%. This method was used for the determination of pesticides in 18 fogwater samples (soluble + insoluble), 31 rainwater samples, and 17 air (gas + particles) samples collected between 1991 and 1993 in Colmar (east of France).

Neurolaena lobata L. promotes wound healing in Sprague Dawley rats

PubMed Central

Nayak, Bijoor Shivananda; Ramlogan, Surrin; Chalapathi Rao, AV; Maharaj, Sandeep

2014-01-01

Background: The leaves of the Neurolaena lobata (Asteraceae) plant are used to control diabetes and heal wounds and infections. Aim: The ethanolic extract of N. lobata leaf was evaluated for its ability to heal inflicted wounds in rats using the excision wound model. Materials and Methods: Animals were divided into three groups of six each. Test group animals were treated topically with an ethanolic extract of N. lobata (1:1 with petroleum jelly, 100 mg/kg/day). Standard and control group animals were treated with mupirocin and petroleum jelly, respectively. Treatment was given for 13 days and the wound area was measured on alternate days. Parameters of healing assessed were the rate of wound contraction, period of epithelialization and hydroxyproline content. Antimicrobial activity of the extract was observed against Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli. Results: Phytochemical analysis of the extract showed the presence of saponins, tannins, alkaloids and flavanoids. Extract-treated animals exhibited 87% reduction in the wound area over 13 days when compared with the control (78%) and standard (83%) groups (P < 0.05). A significant decrease in the epithelialization period was noticed with the extract-treated test group animals compared with the controls and the standard group animals (P < 0.008). The hydroxyproline content of the extract-treated animals was higher (230.5 ± 42.1) when evaluated against the control and (79.0 ± 32.2) and the standard (115.0 ± 44.5) groups (P < 0.05). Conclusion: Increase in the rate of wound contraction and hydroxyproline content with decrease in epithelialization time in extract-treated animals support further evaluation of N. lobata as a pharmacotherapy for wound healing. PMID:25143886

Qualitative and quantitative determination of extractives in heartwood of Scots pine (Pinus sylvestris L.) by gas chromatography.

PubMed

Ekeberg, Dag; Flaete, Per-Otto; Eikenes, Morten; Fongen, Monica; Naess-Andresen, Carl Fredrik

2006-03-24

A method for quantitative determination of extractives from heartwood of Scots pine (Pinus sylvestris L.) using gas chromatography (GC) with flame ionization detection (FID) was developed. The limit of detection (LOD) was 0.03 mg/g wood and the linear range (r = 0.9994) was up to 10 mg/g with accuracy within +/- 10% and precision of 18% relative standard deviation. The identification of the extractives was performed using gas chromatography combined with mass spectrometry (GC-MS). The yields of extraction by Soxhlet were tested for solid wood, small particles and fine powder. Small particles were chosen for further analysis. This treatment gave good yields of the most important extractives: pinosylvin, pinosylvin monomethyl ether, resin acids and free fatty acids. The method is used to demonstrate the variation of these extractives across stems and differences in north-south direction.

Thermal feature extraction of servers in a datacenter using thermal image registration

NASA Astrophysics Data System (ADS)

Liu, Hang; Ran, Jian; Xie, Ting; Gao, Shan

2017-09-01

Thermal cameras provide fine-grained thermal information that enhances monitoring and enables automatic thermal management in large datacenters. Recent approaches employing mobile robots or thermal camera networks can already identify the physical locations of hot spots. Other distribution information used to optimize datacenter management can also be obtained automatically using pattern recognition technology. However, most of the features extracted from thermal images, such as shape and gradient, may be affected by changes in the position and direction of the thermal camera. This paper presents a method for extracting the thermal features of a hot spot or a server in a container datacenter. First, thermal and visual images are registered based on textural characteristics extracted from images acquired in datacenters. Then, the thermal distribution of each server is standardized. The features of a hot spot or server extracted from the standard distribution can reduce the impact of camera position and direction. The results of experiments show that image registration is efficient for aligning the corresponding visual and thermal images in the datacenter, and the standardization procedure reduces the impacts of camera position and direction on hot spot or server features.

Simultaneous determination of flubendiamide its metabolite desiodo flubendiamide residues in cabbage, tomato and pigeon pea by HPLC.

PubMed

Paramasivam, M; Banerjee, Hemanta

2011-10-01

A sensitive and simple method for simultaneous analysis of flubendiamide and its metabolite desiodo flubendiamide in cabbage, tomato and pigeon pea has been developed. The residues were extracted with QuEChERS method followed by dispersive solid-phase extraction with primary secondary amine sorbent to remove co extractives, prior to analysis by HPLC coupled with UV-Vis detector. The recoveries of flubendiamide and desiodo flubendiamide were ranged from 85.1 to 98.5% and 85.9 to 97.1% respectively with relative standard deviations (RSD) less than 5% and sensitivity of 0.01 μg g(-1). The method offers a less expensive and safer alternative to the existing residue analysis methods for vegetables. © Springer Science+Business Media, LLC 2011

A two-step electrodialysis method for DNA purification from polluted metallic environmental samples.

PubMed

Rodríguez-Mejía, José Luis; Martínez-Anaya, Claudia; Folch-Mallol, Jorge Luis; Dantán-González, Edgar

2008-08-01

Extracting DNA from samples of polluted environments using standard methods often results in low yields of poor-quality material unsuited to subsequent manipulation and analysis by molecular biological techniques. Here, we report a novel two-step electrodialysis-based method for the extraction of DNA from environmental samples. This technique permits the rapid and efficient isolation of high-quality DNA based on its acidic nature, and without the requirement for phenol-chloroform-isoamyl alcohol cleanup and ethanol precipitation steps. Subsequent PCR, endonuclease restriction, and cloning reactions were successfully performed utilizing DNA obtained by electrodialysis, whereas some or all of these techniques failed using DNA extracted with two alternative methods. We also show that his technique is applicable to purify DNA from a range of polluted and nonpolluted samples.

Effective and easy to use extraction method shows low numbers of microplastics in offshore planktivorous fish from the northern Baltic Sea.

PubMed

Budimir, Stjepan; Setälä, Outi; Lehtiniemi, Maiju

2018-02-01

Although the presence of microplastics in marine biota has been widely recorded, extraction methods, method validation and approaches to monitoring are not standardized. In this study a method for microplastic extraction from fish guts based on a chemical alkaline digestion is presented. The average particle retrieval rate from spiked fish guts, used for method validation, was 84%. The weight and shape of the test particles (PET, PC, HD-PE) were also analysed with no noticeable changes in any particle shapes and only minor weight change in PET (2.63%). Microplastics were found in 1.8% of herrings (n=164) and in 0.9% of sprat (n=154). None of the three-spined sticklebacks (n=355) contained microplastic particles. Copyright © 2018 Elsevier Ltd. All rights reserved.

Deep Eutectic Solvent-Based Microwave-Assisted Method for Extraction of Hydrophilic and Hydrophobic Components from Radix Salviae miltiorrhizae.

PubMed

Chen, Jue; Liu, Mengjun; Wang, Qi; Du, Huizhi; Zhang, Liwei

2016-10-17

Deep eutectic solvents (DESs) have attracted significant attention as a promising green media. In this work, twenty-five kinds of benign choline chloride-based DESs with microwave-assisted methods were applied to quickly extract active components from Radix Salviae miltiorrhizae . The extraction factors, including temperature, time, power of microwave, and solid/liquid ratio, were investigated systematically by response surface methodology. The hydrophilic and hydrophobic ingredients were extracted simultaneously under the optimized conditions: 20 vol% of water in choline chloride/1,2-propanediol (1:1, molar ratio) as solvent, microwave power of 800 W, temperature at 70 °C, time at 11.11 min, and solid/liquid ratio of 0.007 g·mL -1 . The extraction yield was comparable to, or even better than, conventional methods with organic solvents. The microstructure alteration of samples before and after extraction was also investigated. The method validation was tested as the linearity of analytes ( r ² > 0.9997 over two orders of magnitude), precision (intra-day relative standard deviation (RSD) < 2.49 and inter-day RSD < 2.96), and accuracy (recoveries ranging from 95.04% to 99.93%). The proposed DESs combined with the microwave-assisted method provided a prominent advantage for fast and efficient extraction of active components, and DESs could be extended as solvents to extract and analyze complex environmental and pharmaceutical samples.

Antifouling booster biocide extraction from marine sediments: a fast and simple method based on vortex-assisted matrix solid-phase extraction.

PubMed

Caldas, Sergiane Souza; Soares, Bruno Meira; Abreu, Fiamma; Castro, Ítalo Braga; Fillmann, Gilberto; Primel, Ednei Gilberto

2018-03-01

This paper reports the development of an analytical method employing vortex-assisted matrix solid-phase dispersion (MSPD) for the extraction of diuron, Irgarol 1051, TCMTB (2-thiocyanomethylthiobenzothiazole), DCOIT (4,5-dichloro-2-n-octyl-3-(2H)-isothiazolin-3-one), and dichlofluanid from sediment samples. Separation and determination were performed by liquid chromatography tandem-mass spectrometry. Important MSPD parameters, such as sample mass, mass of C18, and type and volume of extraction solvent, were investigated by response surface methodology. Quantitative recoveries were obtained with 2.0 g of sediment sample, 0.25 g of C18 as the solid support, and 10 mL of methanol as the extraction solvent. The MSPD method was suitable for the extraction and determination of antifouling biocides in sediment samples, with recoveries between 61 and 103% and a relative standard deviation lower than 19%. Limits of quantification between 0.5 and 5 ng g -1 were obtained. Vortex-assisted MPSD was shown to be fast and easy to use, with the advantages of low cost and reduced solvent consumption compared to the commonly employed techniques for the extraction of booster biocides from sediment samples. Finally, the developed method was applied to real samples. Results revealed that the developed extraction method is effective and simple, thus allowing the determination of biocides in sediment samples.

Evaluation of In vitro Anthelmintic Activity, Total Phenolic Content and Cytotoxic Activity of Crinum latifolium L. (Family: Amaryllidaceae).

PubMed

Aziz, Abdul; Sarwar Raju, Golam; Das, Abhijit; Ahmed, Jamiuddin; Moghal, Md Mizanur Rahman

2014-01-01

Crinum latifolium is a widely used plant in Asian folk and traditional medicine.In the present study, we have tried to find out the anthelmintic activity, total phenolic contents and cytotoxicity of the methanolic extract of the target plant. Anthelmintic activity was assessed applying five different concentrations of the plant extract and recording the time of paralysis and death. Total phenolic contents were determined using Folin-Ciocaltu method, using Gallic acid as standard; while brine shrimp lethality test (BSLT) method was used to evaluate the cytotoxicity of the plant extract, where vincristine sulphate and DMSO was used as positive and negative control respectively. The lowest time for paralysis and death of worms, for test sample at highest concentration (50mg/ml), were found 24±0.45 and 46.4±0.60 min respectively, which gradually increased with the decrease of concentration. On the other hand, albendazole, which was used as standard, caused paralysis and death of worms at 56.2±0.20 min and 77.4±0.24 min respectively; whereas no mortality of the worms was observed, when distilled water was used as control. The crude methanolic extract exhibited lower amount of total phenolic content (17.50±2.64 mg/ml). In case of cytotoxicity measurement, the crude methanolic extract showed positive result (with LC50 15.652 µg/ml) compared to standard Vincristine sulphate (0.839 µg/ml); which indicated that the leaves of Crinum latifolium possess mild cytotoxic principles. Therefore, further studies are suggested to evaluate the possible mechanism of action and the active compounds responsible for the biological activities of the plant extract.

Interaction potential of Trigonella foenum graceum through cytochrome P450 mediated inhibition

PubMed Central

Ahmmed, Sk Milan; Mukherjee, Pulok K.; Bahadur, Shiv; Kar, Amit; Mukherjee, Kakali; Karmakar, Sanmoy; Bandyopadhyay, Arun

2015-01-01

Objective: The seeds of Trigonella foenum-graecum (TFG) (family: Leguminosae) are widely consumed both as a spice in food and Traditional Medicine in India. The present study was undertaken to evaluate the inhibitory effect of standardized extract of TFG and its major constituent trigonelline (TG) on rat liver microsome (RLM) and cytochrome P450 (CYP450) drug metabolizing isozymes (CYP3A4 and CYP2D6), which may indicate the possibility of a probable unwanted interaction. Materials and Methods: Reverse phase-high performance liquid chromatography method was developed to standardize the hydroalcoholic seed extract with standard TG. The inhibitory potential of the extract and TG was evaluated on RLM and CYP isozymes using CYP450-carbon monoxide (CYP450-CO) complex assay and fluorescence assay, respectively. Results: The content of TG in TFG was found to be 3.38% (w/w). The CYP-CO complex assay showed 23.32% inhibition on RLM. Fluorescence study revealed that the extract and the biomarker had some inhibition on CYP450 isozymes e.g. CYP3A4 and CYP2D6 (IC50 values of the extract: 102.65 ± 2.63–142.23 ± 2.61 µg/ml and TG: 168.73 ± 4.03–180.90 ± 2.49 µg/ml) which was very less compared to positive controls ketoconazole and quinidine. Inhibition potential of TFG was little higher than TG but very less compared to positive controls. Conclusions: From the present study, we may conclude that the TFG or TG has very less potential to inhibit the CYP isozymes (CYP3A4, CYP2D6), so administration of this plant extract or its biomarker TG may be safe. PMID:26600643

Rapid Quantitation of Ascorbic and Folic Acids in SRM 3280 Multivitamin/Multielement Tablets using Flow-Injection Tandem Mass Spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhandari, Deepak; Kertesz, Vilmos; Van Berkel, Gary J

RATIONALE: Ascorbic acid (AA) and folic acid (FA) are water-soluble vitamins and are usually fortified in food and dietary supplements. For the safety of human health, proper intake of these vitamins is recommended. Improvement in the analysis time required for the quantitative determination of these vitamins in food and nutritional formulations is desired. METHODS: A simple and fast (~5 min) in-tube sample preparation was performed, independently for FA and AA, by mixing extraction solvent with a powdered sample aliquot followed by agitation, centrifugation, and filtration to recover an extract for analysis. Quantitative detection was achieved by flow-injection (1 L injectionmore » volume) electrospray ionization tandem mass spectrometry (ESI-MS/MS) in negative ion mode using the method of standard addition. RESULTS: Method of standard addition was employed for the quantitative estimation of each vitamin in a sample extract. At least 2 spiked and 1 non-spiked sample extract were injected in triplicate for each quantitative analysis. Given an injection-to-injection interval of approximately 2 min, about 18 min was required to complete the quantitative estimation of each vitamin. The concentration values obtained for the respective vitamins in the standard reference material (SRM) 3280 using this approach were within the statistical range of the certified values provided in the NIST Certificate of Analysis. The estimated limit of detections of FA and AA were 13 and 5.9 ng/g, respectively. CONCLUSIONS: Flow-injection ESI-MS/MS was successfully applied for the rapid quantitation of FA and AA in SRM 3280 multivitamin/multielement tablets.« less

General methodology for simultaneous representation and discrimination of multiple object classes

NASA Astrophysics Data System (ADS)

Talukder, Ashit; Casasent, David P.

1998-03-01

We address a new general method for linear and nonlinear feature extraction for simultaneous representation and classification. We call this approach the maximum representation and discrimination feature (MRDF) method. We develop a novel nonlinear eigenfeature extraction technique to represent data with closed-form solutions and use it to derive a nonlinear MRDF algorithm. Results of the MRDF method on synthetic databases are shown and compared with results from standard Fukunaga-Koontz transform and Fisher discriminant function methods. The method is also applied to an automated product inspection problem and for classification and pose estimation of two similar objects under 3D aspect angle variations.

Determination of Antimicrobial Potential of Five Herbs used in Ayurveda Practices against Candida albicans, Candida parapsilosis and Methicillin Resistant Staphylococcus aureus

PubMed Central

Gunasekara, TDCP; Radhika, NDM; Ragunathan, KK; Gunathilaka, DPP; Weerasekera, MM; Hewageegana, HGSP; Arawwawala, L A D M; Fernando, SSN

2017-01-01

Background: Medicinal plants are an important source of novel antimicrobial agents. Ayurvedic treatment involves the use of a variety of medicinal plants that merit investigation. Aims: To investigate the antimicrobial activity of bark of Pongamia pinnata (L.) Pierre, stem of Rubia cordifolia Linn, leaves of Jasminum officinale Linn, stem of Berberis ceylanica C.K. Schneid. and fruit of Garcina zeylanica Roxb. Subjects and Methods: Aqueous and ethanolic extracts of dried bark of Pongamia pinnata (Magul karanda), dried stem of Rubia cordifolia Linn (Welmadata), tender leaves of Jasminum officinale Linn (Jasmine) and dried stem of Berberis ceylanica (Dāruharidrā) were prepared according to standard protocols and tested for antimicrobial activity against five clinical isolates and one standard strain each of Candida albicans (ATCC 10231), Candida parapsilosis (ATCC 22019) and six Methicillin Resistant Staphylococcus aureus (MRSA) clinical isolates using the well diffusion method. Experiments were done in triplicates using well diffusion method. The plant extracts which gave a zone of inhibition in the well diffusion assay were further tested for Minimum Inhibitory Concentrations (MIC). Results: Aqueous and ethanolic extracts of Berberis ceylanica and ethanolic extract of Rubia cordifolia had antimicrobial activity against Candida albicans and Candida parapsilosis. Aqueous and ethanolic extracts of Garcinia zeylanica, and the ethanolic extracts of Jasminum officinale, Rubia cordifolia and Pongamia pinnata had antimicrobial activity against MRSA. Conclusions: Berberis ceylanica and Rubia crodifolia had antimicrobial activity against Candida species while Garcinia zeylanica, Jasminum officinale, Rubia crodifolia and Pongamia pinnata had antimicrobial activity against MRSA. PMID:29269969

Determination of main components in the extracellular polymeric substances extracted from activated sludge using a spectral probing method.

PubMed

Shen, Rong; Sheng, Guo-Ping; Yu, Han-Qing

2012-06-01

In this study, a spectral probing method was applied to determine the content of the main components, i.e., proteins, polysaccharides and humic substances, in the extracellular polymeric substances (EPS) extracted from activated sludge. The measurement results were consistent with those obtained from the conventional methods, such as the anthrone for polysaccharide determination, the modified Lowry method for protein and humic substance determination. The recoveries for the determination of proteins, humic substances and polysaccharides in the EPS extracted from six sludge samples using standard additional method were between 92.4 and 108.9%, 84.8 and 108.9%, 75.1 and 117.2%, respectively. These results indicate that the propose method has a good accuracy and precision, and can be used as an effective approach to determine the main components in sludge EPS. Copyright © 2012 Elsevier B.V. All rights reserved.

Comparison of solvent/derivatization agent systems for determination of extractable toluene diisocyanate from flexible polyurethane foam.

PubMed

Vangronsveld, Erik; Berckmans, Steven; Spence, Mark

2013-06-01

Flexible polyurethane foam (FPF) is produced from the reaction of toluene diisocyanate (TDI) and polyols. Limited and conflicting results exist in the literature concerning the presence of unreacted TDI remaining in FPF as determined by various solvent extraction and analysis techniques. This study reports investigations into the effect of several solvent/derivatization agent combinations on extractable TDI results and suggests a preferred method. The suggested preferred method employs a syringe-based multiple extraction of foam samples with a toluene solution of 1-(2-methoxyphenyl)-piperazine. Extracts are analyzed by liquid chromatography using an ion trap mass spectrometry detection technique. Detection limits of the method are ~10ng TDI g(-1) foam (10 ppb, w/w) for each TDI isomer (i.e. 2,4-TDI and 2,6-TDI). The method was evaluated by a three-laboratory interlaboratory comparison using two representative foam samples. The total extractable TDI results found by the three labs for the two foams were in good agreement (relative standard deviation of the mean of 30-40%). The method has utility as a basis for comparing FPFs, but the interpretation of extractable TDI results using any solvent as the true value for 'free' or 'unreacted' TDI in the foam is problematic, as demonstrated by the difference in the extracted TDI results from the different extraction systems studied. Further, a consideration of polyurethane foam chemistry raises the possibility that extractable TDI may result from decomposition of parts of the foam structure (e.g. dimers, biurets, and allophanates) by the extraction system.

Comparison of five methods for extraction of Legionella pneumophila from respiratory specimens.

PubMed

Wilson, Deborah; Yen-Lieberman, Belinda; Reischl, Udo; Warshawsky, Ilka; Procop, Gary W

2004-12-01

The efficiencies of five commercially available nucleic acid extraction methods were evaluated for the recovery of a standardized inoculum of Legionella pneumophila in respiratory specimens (sputum and bronchoalveolar lavage [BAL] specimens). The concentrations of Legionella DNA recovered from sputa with the automated MagNA Pure (526,200 CFU/ml) and NucliSens (171,800 CFU/ml) extractors were greater than those recovered with the manual methods (i.e., Roche High Pure kit [133,900 CFU/ml], QIAamp DNA Mini kit [46,380 CFU/ml], and ViralXpress kit [13,635 CFU/ml]). The rank order was the same for extracts from BAL specimens, except that for this specimen type the QIAamp DNA Mini kit recovered more than the Roche High Pure kit.

Determination of exogenous epigallocatechin gallate peracetate in mouse plasma using liquid chromatography with quadrupole time-of-flight mass spectrometry.

PubMed

Chu, Kai On; Man, Gene Chi Wai; Chan, Kwok Ping; Chu, Ching Yan; Chan, Tak Hang; Pang, Chi Pui; Wang, Chi Chiu

2014-12-01

A robust method for the quantitation of epigallocatechin gallate peracetate in plasma for pharmacokinetic studies is lacking. We have developed a validated method to quantify this compound using liquid chromatography with quadrupole time-of-flight mass spectrometry with isopropanol and tert-butyl methyl ether (3:10) extraction and thin-layer chromatography purification. The epigallocatechin gallate peracetate-1-(13) C8 isotope was used as an internal standard. The linear range (r(2) > 0.9950) was from 0.05 to 100.00 μg/mL. The lower limit of quantification of the method was 0.05 μg/mL. Reproducibility, coefficient of variation, was between 0.7 and 12.6% (n = 6), accuracy between 83.7 and 104.6% (n = 5), and recovery ranged from 82.4 to 109.0% (n = 4). Ion suppression was approximately 40%. No mass spectral peaks were found to interfere between the standard and internal standard or the blank plasma extracts. Epigallocatechin gallate peracetate in plasma was stably stored at -80°C over three months even after three freeze-thaw cycles. Extracts were stable in the sampler at 4°C for over 48 h. Plasma levels were maintained at 1.36 μg/mL for 360 min after intraorbital intravenous injection at 50 mg/kg in mice. This method can be used to reliably measure epigallocatechin gallate peracetate in plasma for pharmacokinetic studies. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Automated ancillary cancer history classification for mesothelioma patients from free-text clinical reports

PubMed Central

Wilson, Richard A.; Chapman, Wendy W.; DeFries, Shawn J.; Becich, Michael J.; Chapman, Brian E.

2010-01-01

Background: Clinical records are often unstructured, free-text documents that create information extraction challenges and costs. Healthcare delivery and research organizations, such as the National Mesothelioma Virtual Bank, require the aggregation of both structured and unstructured data types. Natural language processing offers techniques for automatically extracting information from unstructured, free-text documents. Methods: Five hundred and eight history and physical reports from mesothelioma patients were split into development (208) and test sets (300). A reference standard was developed and each report was annotated by experts with regard to the patient’s personal history of ancillary cancer and family history of any cancer. The Hx application was developed to process reports, extract relevant features, perform reference resolution and classify them with regard to cancer history. Two methods, Dynamic-Window and ConText, for extracting information were evaluated. Hx’s classification responses using each of the two methods were measured against the reference standard. The average Cohen’s weighted kappa served as the human benchmark in evaluating the system. Results: Hx had a high overall accuracy, with each method, scoring 96.2%. F-measures using the Dynamic-Window and ConText methods were 91.8% and 91.6%, which were comparable to the human benchmark of 92.8%. For the personal history classification, Dynamic-Window scored highest with 89.2% and for the family history classification, ConText scored highest with 97.6%, in which both methods were comparable to the human benchmark of 88.3% and 97.2%, respectively. Conclusion: We evaluated an automated application’s performance in classifying a mesothelioma patient’s personal and family history of cancer from clinical reports. To do so, the Hx application must process reports, identify cancer concepts, distinguish the known mesothelioma from ancillary cancers, recognize negation, perform reference resolution and determine the experiencer. Results indicated that both information extraction methods tested were dependant on the domain-specific lexicon and negation extraction. We showed that the more general method, ConText, performed as well as our task-specific method. Although Dynamic- Window could be modified to retrieve other concepts, ConText is more robust and performs better on inconclusive concepts. Hx could greatly improve and expedite the process of extracting data from free-text, clinical records for a variety of research or healthcare delivery organizations. PMID:21031012

Comparison of indirect and direct quantification of esters of monochloropropanediol in vegetable oil.

PubMed

Dubois, Mathieu; Tarres, Adrienne; Goldmann, Till; Empl, Anna Maria; Donaubauer, Alfred; Seefelder, Walburga

2012-05-04

The presence of fatty acid esters of monochloropropanediol (MEs) in food is a recent concern raised due to the carcinogenicity of their hydrolysable moieties 2- and 3-monochloropropanediol (2- and 3-MCPD). Several indirect methods for the quantification of MEs have been developed and are commonly in use until today, however significant discrepancies among analytical results obtained are challenging their reliability. The aim of the present study was therefore to test the trueness of an indirect method by comparing it to a newly developed direct method using palm oil and palm olein as examples. The indirect method was based on ester cleavage under acidic conditions, derivatization of the liberated 2- and 3-MCPD with heptafluorobutyryl imidazole and GC-MS determination. The direct method was comprised of two extraction procedures targeting 2-and 3-MCPD mono esters (co-extracting as well glycidyl esters) by the use of double solid phase extraction (SPE), and 2- and 3-MCPD di-esters by the use of silica gel column, respectively. Detection was carried out by liquid chromatography coupled to time of flight mass spectrometry (LC-ToF-MS). Accurate quantification of the intact compounds was assured by means of matrix matched standard addition on extracts. Analysis of 22 palm oil and 7 palm olein samples (2- plus 3-MCPD contamination ranged from 0.3 to 8.8 μg/g) by both methods revealed no significant bias. Both methods were therefore considered as comparable in terms of results; however the indirect method was shown to require less analytical standards, being less tedious and furthermore applicable to all type of different vegetable oils and hence recommended for routine application. Copyright © 2012 Elsevier B.V. All rights reserved.

[Extraction of temperate vegetation phenology thresholds in North America based on flux tower observation data].

PubMed

Zhao, Jing-Jing; Liu, Liang-Yun

2013-02-01

Flux tower method can effectively monitor the vegetation seasonal and phenological variation processes. At present, the differences in the detection and quantitative evaluation of various phenology extraction methods were not well validated and quantified. Based on the gross primary productivity (GPP) and net ecosystem productivity (NEP) data of temperate forests from 9 forest FLUXNET sites in North America, and by using the start dates (SOS) and end dates (EOS) of the temperate forest growth seasons extracted by different phenology threshold extraction methods, in combining with the forest ecosystem carbon source/sink functions, this paper analyzed the effects of different threshold standards on the extraction results of the vegetations phenology. The results showed that the effects of different threshold standards on the stability of the extracted results of deciduous broadleaved forest (DBF) phenology were smaller than those on the stability of the extracted results of evergreen needleleaved forest (ENF) phenology. Among the extracted absolute and relative thresholds of the forests GPP, the extracted threshold of the DBF daily GPP= 2 g C.m-2.d-1 had the best agreement with the DBF daily GPP = 20% maximum GPP (GPPmax) , the phenological metrics with a threshold of daily GPP = 4 g C.m-2.d-1 was close to that between daily GPP = 20% GPPmax and daily GPP = 50% GPPmax, and the start date of ecosystem carbon sink function was close to the SOS metrics between daily GPP = 4 g C.m-2.d-1 and daily GPP= 20% GPPmax. For ENF, the phenological metrics with a threshold of daily GPP = 2 g C.m-2.d-1 and daily GPP = 4 g C.m-2.d-1 had the best agreement with the daily GPP = 20% GPPmax and daily GPP = 50% GPPmax, respectively, and the start date of the ecosystem carbon sink function was close to the SOS metrics between daily GPP = 2 g C.m-2.d-1 and daily GPP= 10% GPPmax.

Clonazepam quantification in human plasma by high-performance liquid chromatography coupled with electrospray tandem mass spectrometry in a bioequivalence study.

PubMed

Cavedal, Luiz E; Mendes, Fabiana D; Domingues, Claudia C; Patni, Anil K; Monif, Tausif; Reyar, Simrit; Pereira, Alberto Dos S; Mendes, Gustavo D; De Nucci, Gilberto

2007-01-01

A rapid, sensitive and specific method for quantifying clonazepam in human plasma using diazepam as the internal standard (IS) is described. The analyte and the IS were extracted from plasma by liquid-liquid extraction using a hexane/diethylether (20 : 80, v/v) solution. The extracts were analysed by high-performance liquid chromatography coupled with electrospray tandem mass spectrometry (HPLC-MS-MS). Chromatography was performed on a Jones Genesis C8 4 microm analytical column (100 x 2.1 mm i.d.). The method had a chromatographic run time of 3.0 min and a linear calibration curve over the range 0.5-50 ng/ml (r2 > 0.9965). The limit of quantification was 0.5 ng/ml. This HPLC/MS/MS procedure was used to assess the bioequivalence of two clonazepam 2 mg tablet formulations (clonazepam test formulation from Ranbaxy Laboratories Ltd and Rivotril from Roche Laboratórios Ltda as standard reference formulation). Copyright 2006 John Wiley & Sons, Ltd.

NIST Efforts to Quality-Assure Gunpowder Measurements

NASA Technical Reports Server (NTRS)

MacCrehan, William A.; Reardon, Michelle R.

2000-01-01

In the past few years, the National Institute for Standards and Technology (NIST) has been promoting the idea of quantitatively determining the additives in smokeless gunpowder using micellar capillary electrophoresis as a means of investigating the criminal use of hand guns and pipe bombs. As a part of this effort, we have evaluated both supercritical fluid and ultrasonic solvent extractions for the quantitative recovery of nitroglycerin (NG), diphenylamine (DPA), N-nitrosodiphenylamine (NnDPA), and ethyl centralite (EC) from gunpowder. Recoveries were evaluated by repeat extraction and matrix spiking experiments. The final extraction protocol provides greater than 95 percent recoveries. To help other researches validate their own analytical method for additive determinations, NIST is exploring the development of a standard reference material, Additives in Smokeless Gunpowder. The evaluated method is being applied to two double-base (NG-containing) powders, one stabilized with diphenylamine and the other with ethyl centralite. As part of this reference material development effort, we are conducting an interlaboratory comparison exercise among the forensic and military gunpowder measurement community.

Effect of aqueous and ethanolic extracts of Lippia citriodora on candida albicans

PubMed Central

Ghasempour, Maryam; Omran, Saeid Mahdavi; Moghadamnia, Ali Akbar; Shafiee, Faranak

2016-01-01

Introduction Because of resistance and side effects to common antifungal drugs activity, the research on herbal substances with antifungal activity is frequent. Lemon verbena (Lippia citriodora) is a member of Verbenaceae family. The aim of this study was to determine the anti-candida activities of the ethanolic and aqueous extracts of the lemon verbena leaves and compare them with nystatin and fluconazole. Methods In this 2015 study, 15 clinical isolates and standard strain of candida albicans PTCC 5027 were used, and the inhibitory effects of the ethanolic and aqueous extracts, Nystatin and Fluconazole, were evaluated using disk and well diffusion methods. Also, the minimal inhibitory concentration (MIC) was determined. Five concentrations of aqueous and ethanolic extracts (156–2500 μg/ml), Nystatin (8–128 μg/ml) and Fluconazole (4–64 μg/ml) were used in disk and well diffusion methods, and nine concentrations of aqueous and ethanolic extracts (19–5000 μg/ml), Nystatin (0.5–128 μg/ml), and Fluconazole (0.25–64 μg/ml) were applied for MIC. Data were analyzed using Tukey’s post-hoc and one-way ANOVA tests. The significant level was considered p < 0.05 in the current study. Results In the well and disk diffusion techniques, limited growth inhibition halos were produced around some clinical isolates at different concentrations of ethanolic extract; however, no growth inhibitory halo was observed with any concentrations of the aqueous extract. The MIC values of ethanolic extract, aqueous extract, Nystatin and Fluconazole for clinical isolated and standard strain were 833 ± 78.5and 625μg/ml; 4156 ± 67.4 and 2500 μg/ml; 10.13 ± 1.91 and 4 μg/ml; and 1.97 ± 0.25 and 1 μg/ml, respectively. Conclusion The results showed that the ethanolic extract was stronger than the aqueous extract of this plant, which can be used as an alternative for drugs. It is recommended that the ethanolic extract of this plant be investigated in vivo for better evaluation of its efficacy and properties. PMID:27757185

[Analysis of methylmercury in biological guano by the optimized atomic fluorescence spectrometry coupled with microwave assisted extraction].

PubMed

Chen, Qian-Qian; Liu, Xiao-Dong; Sun, Li-Guang; Jiang, Shan; Yan, Hong; Liu, Yi; Luo, Yu-Han; Huang, Jing

2011-01-01

The analytical method for the determination of methylmercury in seabird excrements was established using atomic fluorescence spectrometry coupled with microwave-assisted extraction In general, temperature and hydrochloric amount are the most important influencing factors on the extraction of MeHg in the samples, and the present paper optimized these two parameters. The result showed that 120 degrees C and 200 microL 6 mol x L(-1) hydrochloric acid are the best extraction conditions. Under these experimental conditions, the relative standard deviation (RSD) values of reduplicative analyses on standard reference material (human hair powder) and the same seabird excrement sample were 0.74% and 6.61% respectively, and their percent recoveries were over 90%. The combination of microwave-assisted extraction and atomic fluorescence spectrometry has many advantages such as simple operation, high sensitivity, low detection limit and low cost, therefore, it is suitable for rapid separation and analysis of trace methylmercury composition in the biological guanos. Using this method, we analyzed the methylmercury contents in the ancient and fresh seabird droppings taken from Xisha Islands of South China Sea, and the result showed that the Xisha guanos were rich in methylmercury and the large input of seabird guanos will cause serious environmental contamination in the remote island ecosystem of Xisha Islands.

Evaluation of antinociceptive activity of aqueous extract of bark of psidium guajava in albino rats and albino mice.

PubMed

Sekhar, N Chandra; Jayasree, T; Ubedulla, Shaikh; Dixit, Rohit; V S, Manohar; J, Shankar

2014-09-01

Psidium guajava is commonly known as guava. Psidium guajava is a medium sized tree belonging to the family Myrtaceae found throughout the tropics. All the parts of the plant, the leaves, followed by the fruits, bark and the roots are used in traditional medicine. The traditional uses of the plant are Antidiarrheal, Antimicrobial Activity, Antimalarial/Antiparasitic Activity, Antitussive and antihyperglycaemic. Leaves are used as Anti-inflammatory, Analgesic and Antinociceptive effects. To evaluate the antinociceptive activity of aqueous extract of bark of Psidium guajava in albino rats with that of control and standard analgesic drugs aspirin and tramadol. Mechanical (Tail clip method) and thermal (Tail flick method using Analgesiometer), 0.6% solution of acetic acid writhing models of nociception were used to evaluate the extract antinociceptive activity. Six groups of animals, each consists of 10 animals, first one as control, second and third as standard drugs, Aspirin and Tramadol, fourth, fifth and sixth groups as text received the extract (100, 200, and 400 mg/ kg) orally 60 min prior to subjection to the respective test. The results obtained demonstrated that aqueous extract of bark of Psidium guajava produced significant antinociceptive response in all the mechanical and thermal-induced nociception models. AEPG antinociceptive activity involves activation of the peripheral and central mechanisms.

Multi-residue pesticide analysis (gas chromatography-tandem mass spectrometry detection)-Improvement of the quick, easy, cheap, effective, rugged, and safe method for dried fruits and fat-rich cereals-Benefit and limit of a standardized apple purée calibration (screening).

PubMed

Rasche, Claudia; Fournes, Britta; Dirks, Uwe; Speer, Karl

2015-07-17

Some steps of the QuEChERS method for the analysis of pesticides with GC-MS/MS in cereals and dried fruits were improved or simplified. For the latter, a mixing vessel with stator-rotor-system proved to be advantageous. The extraction procedure of dried fruits is much easier and safer than the Ultra Turrax and results in excellent validation data at a concentration level of 0.01mg/kg (116 of 118 analytes with recoveries in the range of 70-120%, 117 of 118 analytes with RSD <20%). After qualifying problematic lipophilic pesticides in fat-rich cereals (fat content >7%), predominantly organochlorines showed recoveries of <70% in quantification when the standard QuEChERS method with water was used. A second extraction was carried out analogous to the QuEChERS method, however, without the addition of water. With this simple modification, the problematic lipophilic pesticides, which had been strongly affected by the fat content of the commodities, could be determined with recoveries above 70% even at a concentration level of 0.01mg/kg. Moreover, a GC-MS/MS screening method for 120 pesticides at a concentration level of 0.01mg/kg was established by employing analyte protectants (ethylglycerol, gulonolactone, and sorbitol). The use of only one standardized calibration, made of an apple purée extract in combination with analyte protectants, allowed for a qualitative and quantitative analysis of 120 pesticides in different matrix extracts (tomato, red pepper, sour cherries, dried apples, black currant powder, raisins, wheat flour, rolled oats, wheat germ). The analyte protectants leveled the differences in the matrix-induced protection effect of the analyzed extracts over a wide range. The majority of the pesticides were analyzed with good analytical results (recoveries in the range of 70-120% and RSD <20%). Copyright © 2015 Elsevier B.V. All rights reserved.

Multi-response optimisation of ultrasound-assisted extraction for recovery of flavonoids from red grape skins using response surface methodology.

PubMed

Tomaz, Ivana; Maslov, Luna; Stupić, Domagoj; Preiner, Darko; Ašperger, Danijela; Karoglan Kontić, Jasminka

2016-01-01

For the characterisation of grape cultivars, the profile and content of flavonoids are important because these compounds impact grape and wine quality. To determine the correct profile and content of flavonoids, the use of robust, sensitive and reliable methods is necessary. The object of this research is to develop a new ultrasound-assisted extraction (UAE) method for the recovery of flavonoids from grape skins using response surface methodology. Optimisation of UAE was performed using a complementary study combining a Box-Behnken experimental design with qualitative analysis by high-performance liquid chromatography. Optimal extraction conditions were obtained using the extraction solvent composed of acetonitrile:water:formic acid (26:73:1, v/v/v) at an extraction temperature of 50 °C, an extraction time of 15 min in a single-extraction step and with a solid-to-solvent ratio of 1:80 g/mL. The calculated relative standard deviations for the optimal extraction method were very low, measuring less than 5%. This study demonstrates that numerous factors have strong effects on the extraction efficiency, including the type of organic modifier and its percentage in the extraction solvent, the number of extraction steps, the solid-to-solvent ratio, the extraction time and temperature and, finally, the particular nature of analyte and their position within the grape skin cell. Copyright © 2015 John Wiley & Sons, Ltd.

Magnetic graphene dispersive solid phase extraction combining high performance liquid chromatography for determination of fluoroquinolones in foods.

PubMed

He, Xin; Wang, Geng Nan; Yang, Kun; Liu, Hui Zhi; Wu, Xia Jun; Wang, Jian Ping

2017-04-15

In this study, a magnetic graphene-based dispersive solid phase extraction method was developed that was combined with high performance liquid chromatography to determine the residues of fluoroquinolone drugs in foods of animal origin. During the experiments, several parameters possible influencing the extraction performance were optimized (amount of magnetic graphene, sample pH, extraction time and elution solution). This extraction method showed high absorption capacities (>6800ng) and high enrichment factors (68-79-fold) for seven fluoroquinolones. Furthermore, this absorbent could be reused for at least 40 times. The limits of detection were in the range of 0.05-0.3ng/g, and the recoveries from the standards fortified blank samples (bovine milk, chicken muscle and egg) were in the range of 82.4-108.5%. Therefore, this method could be used as a simple and sensitive tool to determine the residues of fluoroquinolones in foods of animal origin. Copyright © 2016 Elsevier Ltd. All rights reserved.

Preparation of Multiwalled Carbon Nanotubes/Hydroxyl-Terminated Silicone Oil Fiber and Its Application to Analysis of Crude Oils

PubMed Central

Tong, Ting; Zhang, Wanfeng; Dai, Wei; He, Sheng; Chang, Zhenyang; Gao, Xuanbo

2014-01-01

A simple and efficient method to analyze the volatile and semivolatile organic compounds in crude oils has been developed based on direct immersion solid-phase microextraction coupled to comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (DI-SPME-GC × GC/TOFMS). A novel fiber, multiwalled carbon nanotubes/hydroxyl-terminated silicone oil (MWNTs-TSO-OH), was prepared by sol-gel technology. Using standard solutions, the extraction conditions were optimized such as extraction mode, extraction temperature, extraction time, and salts effect. With the optimized conditions, a real crude oil sample was extracted and then analyzed in detail. It shows that the proposed method is very effective in simultaneously analyzing the normal and branched alkanes, cycloalkanes, aromatic hydrocarbons, and biomarkers of crude oil such as steranes and terpanes. Furthermore, the method showed good linearity (r > 0.999), precision (RSD < 8%), and detection limits ranging from 0.2 to 1.6 ng/L. PMID:24578659

Evaluation of analgesic, antipyretic and anti-inflammatory activity on Cordia dichotoma G. Forst. Leaf.

PubMed

Gupta, Richa; Kaur, Jagjit

2015-01-01

Cordia dichotoma G. Forst. is an important medicinal plant of family Boraginaceae. Traditionally, its leaves are used to treat fever, headache, and joint pain but its medicinal activities have not been proven by research. To evaluate the analgesic, anti-inflammatory, and antipyretic activity of C. dichotoma G. Forst. leaf extract. The various extracts of leaf powder were prepared by using soxhlet apparatus. The methanol extract was selected for pharmacological study. To evaluate analgesic activity, Eddy's hot plate method, to study anti-inflammatory activity, carageenan-induced rat paw edema method, and to study antipyretic activity, yeast-induced pyrexia method was used. SD female rats (180-200 g) were used for the study. In all three tests, the methanol extract high dose (400 mg/kg) was found to be highly significant as compared to standard drug. This study proved the traditional uses of plant leaves and concluded the analgesic, anti-inflammatory, and antipyretic activity of the leaf methanol extract.

A high performance liquid chromatography method for determination of furfural in crude palm oil.

PubMed

Loi, Chia Chun; Boo, Huey Chern; Mohammed, Abdulkarim Sabo; Ariffin, Abdul Azis

2011-09-01

A modified steam distillation method was developed to extract furfural from crude palm oil (CPO). The collected distillates were analysed using high performance liquid chromatography (HPLC) coupled with an ultraviolet diode detector at 284nm. The HPLC method allowed identification and quantification of furfural in CPO. The unique thermal extraction of CPO whereby the fresh fruit bunches (FFB) are first subjected to steam treatment, distinguishes itself from other solvent-extracted or cold-pressed vegetable oils. The presence of furfural was also determined in the fresh palm oil from FFB (without undergoing the normal extraction process), palm olein, palm stearin, olive oil, coconut oil, sunflower oil, soya oil and corn oil. The chromatograms of the extracts were compared to that of standard furfural. Furfural was only detected in CPO. The CPO consignments obtained from four mills were shown to contain 7.54 to 20.60mg/kg furfural. Copyright © 2011 Elsevier Ltd. All rights reserved.

Comparison of the Anti-Adhesion Activity of Three Different Cranberry Extracts on Uropathogenic P-fimbriated Escherichia coli: a Randomized, Double-blind, Placebo Controlled, Ex Vivo, Acute Study.

PubMed

Howell, Amy; Souza, Dan; Roller, Marc; Fromentin, Emilie

2015-07-01

Research suggests that cranberry (Vaccinium macrocarpon) helps maintain urinary tract health. Bacterial adhesion to the uroepithelium is the initial step in the progression to development of a urinary tract infection. The bacterial anti-adhesion activity of cranberry proanthocyanidins (PACs) has been demonstrated in vitro. Three different cranberry extracts were developed containing a standardized level of 36 mg of PACs. This randomized, double-blind, placebo controlled, ex vivo, acute study was designed to compare the anti-adhesion activity exhibited by human urine following consumption of three different cranberry extracts on uropathogenic P-fimbriated Escherichia coli in healthy men and women. All three cranberry extracts significantly increased anti-adhesion activity in urine. from 6 to 12 hours after intake of a single dose standardized to deliver 36 mg of PACs (as measured by the BL-DMAC method), versus placebo.

Comparison of the acetyl bromide spectrophotometric method with other analytical lignin methods for determining lignin concentration in forage samples.

PubMed

Fukushima, Romualdo S; Hatfield, Ronald D

2004-06-16

Present analytical methods to quantify lignin in herbaceous plants are not totally satisfactory. A spectrophotometric method, acetyl bromide soluble lignin (ABSL), has been employed to determine lignin concentration in a range of plant materials. In this work, lignin extracted with acidic dioxane was used to develop standard curves and to calculate the derived linear regression equation (slope equals absorptivity value or extinction coefficient) for determining the lignin concentration of respective cell wall samples. This procedure yielded lignin values that were different from those obtained with Klason lignin, acid detergent acid insoluble lignin, or permanganate lignin procedures. Correlations with in vitro dry matter or cell wall digestibility of samples were highest with data from the spectrophotometric technique. The ABSL method employing as standard lignin extracted with acidic dioxane has the potential to be employed as an analytical method to determine lignin concentration in a range of forage materials. It may be useful in developing a quick and easy method to predict in vitro digestibility on the basis of the total lignin content of a sample.

Determination of Porosity in Shale by Double Headspace Extraction GC Analysis.

PubMed

Zhang, Chun-Yun; Li, Teng-Fei; Chai, Xin-Sheng; Xiao, Xian-Ming; Barnes, Donald

2015-11-03

This paper reports on a novel method for the rapid determination of the shale porosity by double headspace extraction gas chromatography (DHE-GC). Ground core samples of shale were placed into headspace vials and DHE-GC measurements of released methane gas were performed at a given time interval. A linear correlation between shale porosity and the ratio of consecutive GC signals was established both theoretically and experimentally by comparing with the results from the standard helium pycnometry method. The results showed that (a) the porosity of ground core samples of shale can be measured within 30 min; (b) the new method is not significantly affected by particle size of the sample; (c) the uncertainties of measured porosities of nine shale samples by the present method range from 0.31 to 0.46 p.u.; and (d) the results obtained by the DHE-GC method are in a good agreement with those from the standard helium pycnometry method. In short, the new DHE-GC method is simple, rapid, and accurate, making it a valuable tool for shale gas-related research and applications.

Polyethylene glycol-based ultrasound-assisted extraction of magnolol and honokiol from Cortex Magnoliae Officinalis.

PubMed

He, Lei; Fan, Tao; Hu, Jianguo; Zhang, Lijin

2015-01-01

In this study, a kind of green solvent named polyethylene glycol (PEG) was developed for the ultrasound-assisted extraction (UAE) of magnolol and honokiol from Cortex Magnoliae Officinalis. The effects of PEG molecular weight, PEG concentration, sample size, pH, ultrasonic power and extraction time on the extraction of magnolol and honokiol were investigated to optimise the extraction conditions. Under the optimal extraction conditions, the PEG-based UAE supplied higher extraction efficiencies of magnolol and honokiol than the ethanol-based UAE and traditional ethanol-reflux extraction. Furthermore, the correlation coefficient (R(2)), repeatability (relative standard deviation, n = 6) and recovery confirmed the validation of the proposed extraction method, which were 0.9993-0.9996, 3.1-4.6% and 92.3-106.8%, respectively.

Dynamic microwave assisted extraction coupled with dispersive micro-solid-phase extraction of herbicides in soybeans.

PubMed

Li, Na; Wu, Lijie; Nian, Li; Song, Ying; Lei, Lei; Yang, Xiao; Wang, Kun; Wang, Zhibing; Zhang, Liyuan; Zhang, Hanqi; Yu, Aimin; Zhang, Ziwei

2015-09-01

Non-polar solvent dynamic microwave assisted extraction was firstly applied to the treatment of high-fat soybean samples. In the dispersive micro-solid-phase extraction (D-µ-SPE), the herbicides in the high-fat extract were directly adsorbed on metal-organic frameworks MIL-101(Cr). The effects of several experimental parameters, including extraction solvent, microwave absorption medium, microwave power, volume and flow rate of extraction solvent, amount of MIL-101(Cr), and D-µ-SPE time, were investigated. At the optimal conditions, the limits of detection for the herbicides ranged from 1.56 to 2.00 μg kg(-1). The relative recoveries of the herbicides were in the range of 91.1-106.7%, and relative standard deviations were equal to or lower than 6.7%. The present method was simple, rapid and effective. A large amount of fat was also removed. This method was demonstrated to be suitable for treatment of high-fat samples. Copyright © 2015 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harman-Ware, Anne E.; Sykes, Robert; Peter, Gary F.

Terpenoids, naturally occurring compounds derived from isoprene units present in pine oleoresin, are a valuable source of chemicals used in solvents, fragrances, flavors, and have shown potential use as a biofuel. This paper describes a method to extract and analyze the terpenoids present in loblolly pine saplings and pine lighter wood. Various extraction solvents were tested over different times and temperatures. Samples were analyzed by pyrolysis-molecular beam mass spectrometry before and after extractions to monitor the extraction efficiency. The pyrolysis studies indicated that the optimal extraction method used a 1:1 hexane/acetone solvent system at 22°C for 1 h. Extracts frommore » the hexane/acetone experiments were analyzed using a low thermal mass modular accelerated column heater for fast-GC/FID analysis. The most abundant terpenoids from the pine samples were quantified, using standard curves, and included the monoterpenes, α- and β-pinene, camphene, and δ-carene. Sesquiterpenes analyzed included caryophyllene, humulene, and α-bisabolene. In conclusion, diterpenoid resin acids were quantified in derivatized extractions, including pimaric, isopimaric, levopimaric, palustric, dehydroabietic, abietic, and neoabietic acids.« less

A simple and selective method for determination of phthalate biomarkers in vegetable samples by high pressure liquid chromatography-electrospray ionization-tandem mass spectrometry.

PubMed

Zhou, Xi; Cui, Kunyan; Zeng, Feng; Li, Shoucong; Zeng, Zunxiang

2016-06-01

In the present study, solid-phase extraction cartridges including silica reversed-phase Isolute C18, polymeric reversed-phase Oasis HLB and mixed-mode anion-exchange Oasis MAX, and liquid-liquid extractions with ethyl acetate, n-hexane, dichloromethane and its mixtures were compared for clean-up of phthalate monoesters from vegetable samples. Best recoveries and minimised matrix effects were achieved using ethyl acetate/n-hexane liquid-liquid extraction for these target compounds. A simple and selective method, based on sample preparation by ultrasonic extraction and liquid-liquid extraction clean-up, for the determination of phthalate monoesters in vegetable samples by liquid chromatography/electrospray ionisation-tandem mass spectrometry was developed. The method detection limits for phthalate monoesters ranged from 0.013 to 0.120 ng g(-1). Good linearity (r(2)>0.991) between MQLs and 1000× MQLs was achieved. The intra- and inter-day relative standard deviation values were less than 11.8%. The method was successfully used to determine phthalate monoester metabolites in the vegetable samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

Longitudinal Analysis of New Information Types in Clinical Notes

PubMed Central

Zhang, Rui; Pakhomov, Serguei; Melton, Genevieve B.

2014-01-01

It is increasingly recognized that redundant information in clinical notes within electronic health record (EHR) systems is ubiquitous, significant, and may negatively impact the secondary use of these notes for research and patient care. We investigated several automated methods to identify redundant versus relevant new information in clinical reports. These methods may provide a valuable approach to extract clinically pertinent information and further improve the accuracy of clinical information extraction systems. In this study, we used UMLS semantic types to extract several types of new information, including problems, medications, and laboratory information. Automatically identified new information highly correlated with manual reference standard annotations. Methods to identify different types of new information can potentially help to build up more robust information extraction systems for clinical researchers as well as aid clinicians and researchers in navigating clinical notes more effectively and quickly identify information pertaining to changes in health states. PMID:25717418

Method optimization for non-equilibrium solid phase microextraction sampling of HAPs for GC/MS analysis

NASA Astrophysics Data System (ADS)

Zawadowicz, M. A.; Del Negro, L. A.

2010-12-01

Hazardous air pollutants (HAPs) are usually present in the atmosphere at pptv-level, requiring measurements with high sensitivity and minimal contamination. Commonly used evacuated canister methods require an overhead in space, money and time that often is prohibitive to primarily-undergraduate institutions. This study optimized an analytical method based on solid-phase microextraction (SPME) of ambient gaseous matrix, which is a cost-effective technique of selective VOC extraction, accessible to an unskilled undergraduate. Several approaches to SPME extraction and sample analysis were characterized and several extraction parameters optimized. Extraction time, temperature and laminar air flow velocity around the fiber were optimized to give highest signal and efficiency. Direct, dynamic extraction of benzene from a moving air stream produced better precision (±10%) than sampling of stagnant air collected in a polymeric bag (±24%). Using a low-polarity chromatographic column in place of a standard (5%-Phenyl)-methylpolysiloxane phase decreased the benzene detection limit from 2 ppbv to 100 pptv. The developed method is simple and fast, requiring 15-20 minutes per extraction and analysis. It will be field-validated and used as a field laboratory component of various undergraduate Chemistry and Environmental Studies courses.

Comparison of Boiling and Robotics Automation Method in DNA Extraction for Metagenomic Sequencing of Human Oral Microbes.

PubMed

Yamagishi, Junya; Sato, Yukuto; Shinozaki, Natsuko; Ye, Bin; Tsuboi, Akito; Nagasaki, Masao; Yamashita, Riu

2016-01-01

The rapid improvement of next-generation sequencing performance now enables us to analyze huge sample sets with more than ten thousand specimens. However, DNA extraction can still be a limiting step in such metagenomic approaches. In this study, we analyzed human oral microbes to compare the performance of three DNA extraction methods: PowerSoil (a method widely used in this field), QIAsymphony (a robotics method), and a simple boiling method. Dental plaque was initially collected from three volunteers in the pilot study and then expanded to 12 volunteers in the follow-up study. Bacterial flora was estimated by sequencing the V4 region of 16S rRNA following species-level profiling. Our results indicate that the efficiency of PowerSoil and QIAsymphony was comparable to the boiling method. Therefore, the boiling method may be a promising alternative because of its simplicity, cost effectiveness, and short handling time. Moreover, this method was reliable for estimating bacterial species and could be used in the future to examine the correlation between oral flora and health status. Despite this, differences in the efficiency of DNA extraction for various bacterial species were observed among the three methods. Based on these findings, there is no "gold standard" for DNA extraction. In future, we suggest that the DNA extraction method should be selected on a case-by-case basis considering the aims and specimens of the study.

Column preconcentration and electrothermal atomic absorption spectrometric determination of rhodium in some food and standard samples.

PubMed

Taher, Mohammad Ali; Pourmohammad, Fatemeh; Fazelirad, Hamid

2015-12-01

In the present work, an electrothermal atomic absorption spectrometric method has been developed for the determination of ultra-trace amounts of rhodium after adsorption of its 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol/tetraphenylborate ion associated complex at the surface of alumina. Several factors affecting the extraction efficiency such as the pH, type of eluent, sample and eluent flow rates, sorption capacity of alumina and sample volume were investigated and optimized. The relative standard deviation for eight measurements of 0.1 ng/mL of rhodium was ±6.3%. In this method, the detection limit was 0.003 ng/mL in the original solution. The sorption capacity of alumina and the linear range for Rh(III) were evaluated as 0.8 mg/g and 0.015-0.45 ng/mL in the original solution, respectively. The proposed method was successfully applied for the extraction and determination of rhodium content in some food and standard samples with high recovery values. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A novel strategy with standardized reference extract qualification and single compound quantitative evaluation for quality control of Panax notoginseng used as a functional food.

PubMed

Li, S P; Qiao, C F; Chen, Y W; Zhao, J; Cui, X M; Zhang, Q W; Liu, X M; Hu, D J

2013-10-25

Root of Panax notoginseng (Burk.) F.H. Chen (Sanqi in Chinese) is one of traditional Chinese medicines (TCMs) based functional food. Saponins are the major bioactive components. The shortage of reference compounds or chemical standards is one of the main bottlenecks for quality control of TCMs. A novel strategy, i.e. standardized reference extract based qualification and single calibrated components directly quantitative estimation of multiple analytes, was proposed to easily and effectively control the quality of natural functional foods such as Sanqi. The feasibility and credibility of this methodology were also assessed with a developed fast HPLC method. Five saponins, including ginsenoside Rg1, Re, Rb1, Rd and notoginsenoside R1 were rapidly separated using a conventional HPLC in 20 min. The quantification method was also compared with individual calibration curve method. The strategy is feasible and credible, which is easily and effectively adapted for improving the quality control of natural functional foods such as Sanqi. Copyright © 2013 Elsevier B.V. All rights reserved.

High-throughput immunomagnetic scavenging technique for quantitative analysis of live VX nerve agent in water, hamburger, and soil matrixes.

PubMed

Knaack, Jennifer S; Zhou, Yingtao; Abney, Carter W; Prezioso, Samantha M; Magnuson, Matthew; Evans, Ronald; Jakubowski, Edward M; Hardy, Katelyn; Johnson, Rudolph C

2012-11-20

We have developed a novel immunomagnetic scavenging technique for extracting cholinesterase inhibitors from aqueous matrixes using biological targeting and antibody-based extraction. The technique was characterized using the organophosphorus nerve agent VX. The limit of detection for VX in high-performance liquid chromatography (HPLC)-grade water, defined as the lowest calibrator concentration, was 25 pg/mL in a small, 500 μL sample. The method was characterized over the course of 22 sample sets containing calibrators, blanks, and quality control samples. Method precision, expressed as the mean relative standard deviation, was less than 9.2% for all calibrators. Quality control sample accuracy was 102% and 100% of the mean for VX spiked into HPLC-grade water at concentrations of 2.0 and 0.25 ng/mL, respectively. This method successfully was applied to aqueous extracts from soil, hamburger, and finished tap water spiked with VX. Recovery was 65%, 81%, and 100% from these matrixes, respectively. Biologically based extractions of organophosphorus compounds represent a new technique for sample extraction that provides an increase in extraction specificity and sensitivity.

An effective identification and quantification method for Ginkgo biloba flavonol glycosides with targeted evaluation of adulterated products.

PubMed

Ma, Yuan-Chun; Mani, Ana; Cai, Yaling; Thomson, Jaclyn; Ma, Jie; Peudru, Flavie; Chen, Sarah; Luo, Mai; Zhang, Junzeng; Chapman, Robert G; Shi, Zhen-Tuo

2016-04-15

Ginkgo biloba L. (Ginkgoaceae) leaf extract is one of the most popular herbal products on the market, as it contains flavone glycosides (≥ 24%) and terpene lactones (≥ 6%), which are proposed to have significant physiological effects. Unfortunately, the challenging financial climate has resulted in a natural health product market containing adulterated ginkgo products. 42 ginkgo samples were analyzed to establish an HPLC profile for authentic ginkgo and common ginkgo adulterants, and to develop a method capable of easily detecting adulteration in ginkgo commercial products. In this study an efficient and targeted HPLC analysis method was established that is capable of distinguishing flavonol glycosides and aglycones simultaneously for the evaluation of ginkgo powdered extracts (PEs) and finished products in a single, 13 min run. Thirteen ginkgo leaf samples, fifteen standardized powdered extracts, and fourteen commercially available ginkgo products have been analyzed using this new HPLC method. Chromatograms were compared to six standard reference materials: one flavonol glycoside (rutin), three aglycones (quercetin, kaempferol and isorhamnetin), and two isoflavones (genestin and genistein). The quantitative chromatographic data was interpreted by principal component analysis (PCA), which assisted in the detection of unexpected chromatographic features in various adulterated botanical products. Only three of the commercially available ginkgo finished products tested in this study were determined to be authentic, with flavonol glycoside rutin, and aglycones quercetin, kaempferol, and isorhamnetin found to be common adulterants in the ginkgo powdered extract and finished product samples. Despite evidence of adulteration in most of the samples, each of the samples discussed herein met most of the current pharmacopeial standards. It is therefore critical that a preliminary evaluation be utilized to detect adulteration in commercial ginkgo products, prior to the acid hydrolysis procedure utilized in the current testing methods. Copyright © 2016 Elsevier GmbH. All rights reserved.

Screening of metabolites secondary compounds in extract of moringa fruit and determination of inhibitory effect on growth of the fungus Candida albicans

NASA Astrophysics Data System (ADS)

Nuryanti, Siti; Puspitasari, Dwi Juli

2017-08-01

Moringa (Moringa oleifera Lamk) is a nutritious plant that can cure various diseases. Parts of this plant like leave, root, flower, and fruit can be used as a traditional medicine. The research about screening of secondary metabolites in moringa extracts and the determination of their inhibitory effect on growth of the fungus Candida albicans have been done. This research was conducted by extracting the moringa fruit with various solvent with different polarity namely hexane, distilled water and ethanol. The fungal inhibition test was done by well-difuse method. Suspensions of Candida albicans was standardized by 0.5 Mc Farland standard. The results showed that the extracts of Moringa with distilled water provided the greatest inhibition on the growth of the fungus Candida albicans compared to moringa fruit extracted by ethanol and hexane. The percentages inhibition of Moringa extracts on the growth of the Candida albicans with distilled water, ethanol and hexane solvents were 89.90%, 57.90% and 8.97% respectively. Phytochemical screening test showed that the moringa fruit contain alkaloids, flavonoids and steroids.

[Establishment of the mathematic model of total quantum statistical moment standard similarity for application to medical theoretical research].

PubMed

He, Fu-yuan; Deng, Kai-wen; Huang, Sheng; Liu, Wen-long; Shi, Ji-lian

2013-09-01

The paper aims to elucidate and establish a new mathematic model: the total quantum statistical moment standard similarity (TQSMSS) on the base of the original total quantum statistical moment model and to illustrate the application of the model to medical theoretical research. The model was established combined with the statistical moment principle and the normal distribution probability density function properties, then validated and illustrated by the pharmacokinetics of three ingredients in Buyanghuanwu decoction and of three data analytical method for them, and by analysis of chromatographic fingerprint for various extracts with different solubility parameter solvents dissolving the Buyanghanwu-decoction extract. The established model consists of four mainly parameters: (1) total quantum statistical moment similarity as ST, an overlapped area by two normal distribution probability density curves in conversion of the two TQSM parameters; (2) total variability as DT, a confidence limit of standard normal accumulation probability which is equal to the absolute difference value between the two normal accumulation probabilities within integration of their curve nodical; (3) total variable probability as 1-Ss, standard normal distribution probability within interval of D(T); (4) total variable probability (1-beta)alpha and (5) stable confident probability beta(1-alpha): the correct probability to make positive and negative conclusions under confident coefficient alpha. With the model, we had analyzed the TQSMS similarities of pharmacokinetics of three ingredients in Buyanghuanwu decoction and of three data analytical methods for them were at range of 0.3852-0.9875 that illuminated different pharmacokinetic behaviors of each other; and the TQSMS similarities (ST) of chromatographic fingerprint for various extracts with different solubility parameter solvents dissolving Buyanghuanwu-decoction-extract were at range of 0.6842-0.999 2 that showed different constituents with various solvent extracts. The TQSMSS can characterize the sample similarity, by which we can quantitate the correct probability with the test of power under to make positive and negative conclusions no matter the samples come from same population under confident coefficient a or not, by which we can realize an analysis at both macroscopic and microcosmic levels, as an important similar analytical method for medical theoretical research.

Obtaining a Dry Extract from the Mikania laevigata Leaves with Potential for Antiulcer Activity

PubMed Central

Pinto, Mariana Viana; Oliveira, Ezequiane Machado; Martins, Jose Luiz Rodrigues; de Paula, Jose Realino; Costa, Elson Alves; da Conceição, Edemilson Cardoso; Bara, Maria Teresa Freitas

2017-01-01

Background: Mikania laevigata leaves are commonly used in Brazil as a medicinal plant. Objective: To obtain hydroalcoholic dried extract by nebulization and evaluate its antiulcerogenic potential. Materials and Methods: Plant material and hydroalcoholic extract were processed and analyzed for their physicochemical characteristics. A method using HPLC was validated to quantify coumarin and o-coumaric acid. Hydroalcoholic extract was spray dried and the powder obtained was characterized in terms of its physicochemical parameters and potential for antiulcerogenic activity. Results: The analytical method proved to be selective, linear, precise, accurate, sensitive, and robust. M. laevigata spray dried extract was obtained using colloidal silicon dioxide as adjuvant and was shown to possess 1.83 ± 0.004% coumarin and 0.80 ± 0.012% o-coumaric acid. It showed significant antiulcer activity in a model of an indomethacin-induced gastric lesion in mice and also produced a gastroprotective effect. Conclusion: This dried extract from M. laevigata could be a promising intermediate phytopharmaceutical product. SUMMARY Research and development of standardized dried extract of Mikania laevigata leaves obtained through spray drying and the production process was monitored by the chemical profile, physicochemical properties and potential for anti-ulcerogenic activity. Abbreviations used: DE: M. laevigata spray dried extract, HE: hydroalcoholic extract. PMID:28216886

Antioxidant activity of Syzygium cumini leaf gall extracts

PubMed Central

Eshwarappa, Ravi Shankara Birur; Iyer, Raman Shanthi; Subbaramaiah, Sundara Rajan; Richard, S Austin; Dhananjaya, Bhadrapura Lakkappa

2014-01-01

Introduction: Free radicals are implicated in several metabolic diseases and the medicinal properties of plants have been explored for their potent antioxidant activities to counteract metabolic disorders. This research highlights the chemical composition and antioxidant potential of leaf gall extracts (aqueous and methanol) of Syzygium cumini (S. cumini), which have been extensively used in traditional medications to treat various metabolic diseases. Methods: The antioxidant activities of leaf gall extracts were examined using diphenylpicrylhydrazyl (DPPH), nitric oxide scavenging, hydroxyl scavenging and ferric reducing power (FRAP) methods. Results: In all the methods, the methanolic extract showed higher antioxidant potential than the standard ascorbic acid. The presence of phenolics, flavonoids, phytosterols, terpenoids, and reducing sugars was identified in both the extracts. When compared, the methanol extract had the highest total phenolic and flavonoid contents at 474±2.2 mg of GAE/g d.w and 668±1.4 mg of QUE/g d.w, respectively. The significant high antioxidant activity can be positively correlated to the high content of total polyphenols/flavonoids of the methanol extract. Conclusion: The present study confirms the folklore use of S. cumini leaves gall extracts as a natural antioxidant and justifies its ethnobotanical use. Further, the result of antioxidant properties encourages the use of S. cumini leaf gall extracts for medicinal health, functional food and nutraceuticals applications. PMID:25035854

Current lipid extraction methods are significantly enhanced adding a water treatment step in Chlorella protothecoides.

PubMed

Ren, Xiaojie; Zhao, Xinhe; Turcotte, François; Deschênes, Jean-Sébastien; Tremblay, Réjean; Jolicoeur, Mario

2017-02-11

Microalgae have the potential to rapidly accumulate lipids of high interest for the food, cosmetics, pharmaceutical and energy (e.g. biodiesel) industries. However, current lipid extraction methods show efficiency limitation and until now, extraction protocols have not been fully optimized for specific lipid compounds. The present study thus presents a novel lipid extraction method, consisting in the addition of a water treatment of biomass between the two-stage solvent extraction steps of current extraction methods. The resulting modified method not only enhances lipid extraction efficiency, but also yields a higher triacylglycerols (TAG) ratio, which is highly desirable for biodiesel production. Modification of four existing methods using acetone, chloroform/methanol (Chl/Met), chloroform/methanol/H 2 O (Chl/Met/H 2 O) and dichloromethane/methanol (Dic/Met) showed respective lipid extraction yield enhancement of 72.3, 35.8, 60.3 and 60.9%. The modified acetone method resulted in the highest extraction yield, with 68.9 ± 0.2% DW total lipids. Extraction of TAG was particularly improved with the water treatment, especially for the Chl/Met/H 2 O and Dic/Met methods. The acetone method with the water treatment led to the highest extraction level of TAG with 73.7 ± 7.3 µg/mg DW, which is 130.8 ± 10.6% higher than the maximum value obtained for the four classical methods (31.9 ± 4.6 µg/mg DW). Interestingly, the water treatment preferentially improved the extraction of intracellular fractions, i.e. TAG, sterols, and free fatty acids, compared to the lipid fractions of the cell membranes, which are constituted of phospholipids (PL), acetone mobile polar lipids and hydrocarbons. Finally, from the 32 fatty acids analyzed for both neutral lipids (NL) and polar lipids (PL) fractions, it is clear that the water treatment greatly improves NL-to-PL ratio for the four standard methods assessed. Water treatment of biomass after the first solvent extraction step helps the subsequent release of intracellular lipids in the second extraction step, thus improving the global lipids extraction yield. In addition, the water treatment positively modifies the intracellular lipid class ratios of the final extract, in which TAG ratio is significantly increased without changes in the fatty acids composition. The novel method thus provides an efficient way to improve lipid extraction yield of existing methods, as well as selectively favoring TAG, a lipid of the upmost interest for biodiesel production.

Solid-phase extraction and GC-MS analysis of THC-COOH method optimized for a high-throughput forensic drug-testing laboratory.

PubMed

Stout, P R; Horn, C K; Klette, K L

2001-10-01

In order to facilitate the confirmation analysis of large numbers of urine samples previously screened positive for delta9-tetrahydrocannabinol (THC), an extraction, derivitization, and GC-MS analysis method was developed. This method utilized a positive pressure manifold anion-exchange polymer-based solid-phase extraction followed by elution directly into the automated liquid sampling (ALS) vials. Rapid derivitization was accomplished using pentafluoropropionic anhydride/pentafluoropropanol (PFPA/PFPOH). Recoveries averaged 95% with a limit of detection of 0.875 ng/mL with a 3-mL sample volume. Performance of 11-nor-delta9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH)-d3 and THC-COOH-d9 internal standards were evaluated. The method was linear to 900 ng/mL THC-COOH using THC-COOH-d9 with negligible contribution from the internal standard to very weak samples. Excellent agreement was seen with previous quantitations of human urine samples. More than 1000 human urine samples were analyzed using the method with 300 samples analyzed using an alternate qualifier ion (m/z 622) after some interference was observed with a qualifier ion (m/z 489). The 622 ion did not exhibit any interference even in samples with interfering peaks present in the 489 ion. The method resulted in dramatic reductions in processing time, waste production, and exposure hazards to laboratory personnel.

Development and Validation of HPLC Method for Determination of Crocetin, a constituent of Saffron, in Human Serum Samples

PubMed Central

Mohammadpour, Amir Hooshang; Ramezani, Mohammad; Tavakoli Anaraki, Nasim; Malaekeh-Nikouei, Bizhan; Amel Farzad, Sara; Hosseinzadeh, Hossein

2013-01-01

Objective(s): The present study reports the development and validation of a sensitive and rapid extraction method beside high performance liquid chromatographic method for the determination of crocetin in human serum. Materials and Methods: The HPLC method was carried out by using a C18 reversed-phase column and a mobile phase composed of methanol/water/acetic acid (85:14.5:0.5 v/v/v) at the flow rate of 0.8 ml/min. The UV detector was set at 423 nm and 13-cis retinoic acid was used as the internal standard. Serum samples were pretreated with solid-phase extraction using Bond Elut C18 (200mg) cartridges or with direct precipitation using acetonitrile. Results: The calibration curves were linear over the range of 0.05-1.25 µg/ml for direct precipitation method and 0.5-5 µg/ml for solid-phase extraction. The mean recoveries of crocetin over a concentration range of 0.05-5 µg/ml serum for direct precipitation method and 0.5-5 µg/ml for solid-phase extraction were above 70 % and 60 %, respectively. The intraday coefficients of variation were 0.37- 2.6% for direct precipitation method and 0.64 - 5.43% for solid-phase extraction. The inter day coefficients of variation were 1.69 – 6.03% for direct precipitation method and 5.13-12.74% for solid-phase extraction, respectively. The lower limit of quantification for crocetin was 0.05 µg/ml for direct precipitation method and 0.5 µg/ml for solid-phase extraction. Conclusion: The validated direct precipitation method for HPLC satisfied all of the criteria that were necessary for a bioanalytical method and could reliably quantitate crocetin in human serum for future clinical pharmacokinetic study. PMID:23638292

Extraction of trace elements by ultrasound-assisted emulsification from edible oils producing detergentless microemulsions.

PubMed

Kara, Derya; Fisher, Andrew; Hill, Steve

2015-12-01

The aim of this study is to develop a new method for the extraction and preconcentration of trace elements from edible oils via an ultrasound-assisted extraction using ethylenediaminetetraacetic acid (EDTA) producing detergentless microemulsions. These were then analyzed using ICP-MS against matrix matched standards. Optimum experimental conditions were determined and the applicability of the proposed ultrasound-assisted extraction method was investigated. Under the optimal conditions, the detection limits (μg kg(-1)) were 2.47, 2.81, 0.013, 0.037, 1.37, 0.050, 0.049, 0.47, 0.032 and 0.087 for Al, Ca, Cd, Cu, Mg, Mn, Ni, Ti, V and Zn respectively for edible oils (3Sb/m). The accuracy of the developed method was checked by analyzing certified reference material. The proposed method was applied to different edible oils such as sunflower seed oil, rapeseed oil, olive oil and cod liver oil. Copyright © 2015 Elsevier Ltd. All rights reserved.

Nonlinear features for classification and pose estimation of machined parts from single views

NASA Astrophysics Data System (ADS)

Talukder, Ashit; Casasent, David P.

1998-10-01

A new nonlinear feature extraction method is presented for classification and pose estimation of objects from single views. The feature extraction method is called the maximum representation and discrimination feature (MRDF) method. The nonlinear MRDF transformations to use are obtained in closed form, and offer significant advantages compared to nonlinear neural network implementations. The features extracted are useful for both object discrimination (classification) and object representation (pose estimation). We consider MRDFs on image data, provide a new 2-stage nonlinear MRDF solution, and show it specializes to well-known linear and nonlinear image processing transforms under certain conditions. We show the use of MRDF in estimating the class and pose of images of rendered solid CAD models of machine parts from single views using a feature-space trajectory neural network classifier. We show new results with better classification and pose estimation accuracy than are achieved by standard principal component analysis and Fukunaga-Koontz feature extraction methods.

[Determination of 44 organophosphorus pesticides in food by SPE disk extraction-capillary gas chromatography with pulsed flame photometric detection].

PubMed

Luo, Xiao-Fei; Yang, Yuan; Sun, Cheng-Jun

2012-01-01

To develop a method for the simultaneous determination of 44 organophosphorus pesticides in food by SPE disk extraction-capillary gas chromatography with pulsed flame photometric detection. Organophosphorus pesticides in food were extracted ultrasonically with water. Then the extract was cleaned-up with SPE disk and eluted with ethyl acetate. Finally the eluent was condensed to 1mL under N2 at 55 degrees C. Gas chromatography was applied for quantitative detection of the organophosphorus pesticides in the sample. The linear range of the method for all the pesticides were in the range of 0.01-0.5 mg/kg with correlation coefficients of 0.992-1.000. The detection limits of the method were in the range of 0.0005-0.01 mg/kg. The recoveries for most pesticides were 60%-120% with relative standard deviations of less than 15%. The method is simple, sensitive, environmentally friendly and suitable for the determination of organophosphorous pesticides in food.

Determination of sulfonamides in butter samples by ionic liquid magnetic bar liquid-phase microextraction high-performance liquid chromatography.

PubMed

Wu, Lijie; Song, Ying; Hu, Mingzhu; Xu, Xu; Zhang, Hanqi; Yu, Aimin; Ma, Qiang; Wang, Ziming

2015-01-01

A novel, simple, and environmentally friendly pretreatment method, ionic liquid magnetic bar liquid-phase microextraction, was developed for the determination of sulfonamides in butter samples by high-performance liquid chromatography. The ionic liquid magnetic bar was prepared by inserting a stainless steel wire into the hollow of a hollow fiber and immobilizing ionic liquid in the micropores of the hollow fiber. In the extraction process, the ionic liquid magnetic bars were used to stir the mixture of sample and extraction solvent and enrich the sulfonamides in the mixture. After extraction, the analyte-adsorbed ionic liquid magnetic bars were readily isolated with a magnet from the extraction system. It is notable that the present method was environmentally friendly since water and only several microliters of ionic liquid were used in the whole extraction process. Several parameters affecting the extraction efficiency were investigated and optimized, including the type of ionic liquid, sample-to-extraction solvent ratio, the number of ionic liquid magnetic bars, extraction temperature, extraction time, salt concentration, stirring speed, pH of the extraction solvent, and desorption conditions. The recoveries were in the range of 73.25-103.85 % and the relative standard deviations were lower than 6.84 %. The experiment results indicated that the present method was effective for the extraction of sulfonamides in high-fat content samples.

Improved tandem mass spectrometry (MS/MS) derivatized method for the detection of tyrosinemia type I, amino acids and acylcarnitine disorders using a single extraction process.

PubMed

Dhillon, Kuldeep S; Bhandal, Ajit S; Aznar, Constantino P; Lorey, Fred W; Neogi, Partha

2011-05-12

Succinylacetone (SUAC), a specific marker for tyrosinemia type I (Tyr I) cannot be detected by the routine LC-MS/MS screening of amino acids (AA) and acylcarnitines (AC) in newborns. The current derivatized methods require double extraction of newborn dried blood spots (DBS); one for AA and AC and the second for SUAC from the blood spot left after the first extraction. We have developed a method in which AA, AC and SUAC are extracted in a single extraction resulting in significant reduction in labor and assay time. The 3.2 mm DBS were extracted by incubating at 45 °C for 45 min with 100 μl of acetonitrile (ACN)-water-formic acid mixture containing hydrazine and stable-isotope labeled internal standards of AA, AC and SUAC. The extract was derivatized with n-butanolic-HCl and analyzed by LC-MS/MS. The average inter-assay CVs for, AA, AC and SUAC were 10.1, 10.8 and 7.1% respectively. The extraction of analytes with ACN-water mixture showed no significant difference in their recovery compared to commonly used solvent MeOH. The concentration of hydrazine had considerable impact on SUAC extraction. We developed a new MS/MS derivatized method to detect AA/AC/SUAC in a single extraction process for screening Tyr I along with disorders of AA and AC. Published by Elsevier B.V.

Analysis of trace dicyandiamide in stream water using solid phase extraction and liquid chromatography UV spectrometry.

PubMed

Qiu, Huidong; Sun, Dongdi; Gunatilake, Sameera R; She, Jinyan; Mlsna, Todd E

2015-09-01

An improved method for trace level quantification of dicyandiamide in stream water has been developed. This method includes sample pretreatment using solid phase extraction. The extraction procedure (including loading, washing, and eluting) used a flow rate of 1.0mL/min, and dicyandiamide was eluted with 20mL of a methanol/acetonitrile mixture (V/V=2:3), followed by pre-concentration using nitrogen evaporation and analysis with high performance liquid chromatography-ultraviolet spectroscopy (HPLC-UV). Sample extraction was carried out using a Waters Sep-Pak AC-2 Cartridge (with activated carbon). Separation was achieved on a ZIC(®)-Hydrophilic Interaction Liquid Chromatography (ZIC-HILIC) (50mm×2.1mm, 3.5μm) chromatography column and quantification was accomplished based on UV absorbance. A reliable linear relationship was obtained for the calibration curve using standard solutions (R(2)>0.999). Recoveries for dicyandiamide ranged from 84.6% to 96.8%, and the relative standard deviations (RSDs, n=3) were below 6.1% with a detection limit of 5.0ng/mL for stream water samples. Copyright © 2015. Published by Elsevier B.V.

Relative extraction ratio (RER) for arsenic and heavy metals in soils and tailings from various metal mines, Korea.

PubMed

Son, Hye Ok; Jung, Myung Chae

2011-01-01

This study focused on the evaluation of leaching behaviours for arsenic and heavy metals (Cd, Cu, Ni, Pb and Zn) in soils and tailings contaminated by mining activities. Ten representative mine soils were taken at four representative metal mines in Korea. To evaluate the leaching characteristics of the samples, eight extraction methods were adapted namely 0.1 M HCl, 0.5 M HCl, 1.0 M HCl, 3.0 M HCl, Korean Standard Leaching Procedure for waste materials (KSLP), Synthetic Precipitation Leaching Procedure (SPLP), Toxicity Characteristic Leaching Procedure (TCLP) and aqua regia extraction (AR) methods. In order to compare element concentrations as extraction methods, relative extraction ratios (RERs, %), defined as element concentration extracted by the individual leaching method divided by that extracted by aqua regia based on USEPA method 3050B, were calculated. Although the RER values can vary upon sample types and elements, they increase with increasing ionic strength of each extracting solution. Thus, the RER for arsenic and heavy metals in the samples increased in the order of KSLP < SPLP < TCLP < 0.1 M HCl < 0.5 M HCl < 1.0 M HCl < 3.0 M HCl. In the same extraction method, the RER values for Cd and Zn were relatively higher than those for As, Cu, Ni and Pb. This may be due to differences in geochemical behaviour of each element, namely high solubility of Cd and Zn and low solubility of As, Cu, Ni and Pb in surface environment. Thus, the extraction results can give important information on the degree and extent of arsenic and heavy metal dispersion in the surface environment.

A novel sorptive extraction method based on polydimethylsiloxane frit for determination of lung cancer biomarkers in human serum.

PubMed

Xu, Hui; Wang, Shuyu

2012-04-29

In this study, a porous polypropylene frit was coated with polydimethylsiloxane (PDMS) as extraction medium, based on the home-made PDMS-frit, a rapid, simple and sensitive sorptive extraction method was established for analysis of potential biomarkers of lung cancer (hexanal and heptanal) in human serum samples. In the method, derivatization and extraction occurred simultaneously on the PDMS-frit, then the loaded frit was ultrasonically desorbed in acetonitrile. Polymerization, derivatization-extraction and desorption conditions were optimized. Under the optimal conditions, satisfactory results were gained, a wide linear application range was obtained in the range of 0.002-5.0 μmol L(-1) (R>0.997) for two aldehydes, the detection limits (SN(-1)=3) were 0.5 nmol L(-1) for hexanal and 0.4 nmol L(-1) for heptanal. The relative standard deviations (RSDs, n=5) of the method were below 7.9% and the recoveries were above 72.7% for the spiked serum. All these results hint that the proposed method is potential for disease markers analysis in complex biological samples. Copyright © 2012 Elsevier B.V. All rights reserved.

Applications of Evolutionary Algorithms to Electromagnetic Materials Characterization and Design Problems

NASA Astrophysics Data System (ADS)

Frasch, Jonathan Lemoine

Determining the electrical permittivity and magnetic permeability of materials is an important task in electromagnetics research. The method using reflection and transmission scattering parameters to determine these constants has been widely employed for many years, ever since the work of Nicolson, Ross, and Weir in the 1970's. For general materials that are homogeneous, linear, and isotropic, the method they developed (the NRW method) works very well and provides an analytical solution. For materials which possess a metal backing or are applied as a coating to a metal surface, it can be difficult or even impossible to obtain a transmission measurement, especially when the coating is thin. In such a circumstance, it is common to resort to a method which uses two reflection type measurements. There are several such methods for free-space measurements, using multiple angles or polarizations for example. For waveguide measurements, obtaining two independent sources of information from which to extract two complex parameters can be a challenge. This dissertation covers three different topics. Two of these involve different techniques to characterize conductor-backed materials, and the third proposes a method for designing synthetic validation standards for use with standard NRW measurements. All three of these topics utilize modal expansions of electric and magnetic fields to analyze propagation in stepped rectangular waveguides. Two of the projects utilize evolutionary algorithms (EA) to design waveguide structures. These algorithms were developed specifically for these projects and utilize fairly recent innovations within the optimization community. The first characterization technique uses two different versions of a single vertical step in the waveguide. Samples to be tested lie inside the steps with the conductor reflection plane behind them. If the two reflection measurements are truly independent it should be possible to recover the values of two complex parameters, but success of the technique ultimately depends upon how independent the measurements actually are. Next, a method is demonstrated for developing synthetic verification standards. These standards are created from combinations of vertical steps formed from a single piece of metal or metal coated plastic. These fully insertable structures mimic some of the measurement characteristics of typical lab specimens and thus provide a useful tool for verifying the proper calibration and function of the experimental setup used for NRW characterization. These standards are designed with the use an EA, which compares possible designs based on the quality of the match with target parameter values. Several examples have been fabricated and tested, and the design specifications and results are presented. Finally, a second characterization technique is considered. This method uses multiple vertical steps to construct an error reducing structure within the waveguide, which allows parameters to be reliably extracted using both reflection and transmission measurements. These structures are designed with an EA, measuring fitness by the reduction of error in the extracted parameters. An additional EA is used to assist in the extraction of the material parameters supplying better initial guesses to a secant method solver. This hybrid approach greatly increases the stability of the solver and increases the speed of parameter extractions. Several designs have been identified and are analyzed.

Multiresidue determination of 114 multiclass pesticides in flue-cured tobacco by solid-phase extraction coupled with gas chromatography and tandem mass spectrometry.

PubMed

Cao, Jianmin; Sun, Na; Yu, Weisong; Pang, Xueli; Lin, Yingnan; Kong, Fanyu; Qiu, Jun

2016-12-01

A sensitive and robust multiresidue method for the simultaneous analysis of 114 pesticides in tobacco was developed based on solid-phase extraction coupled with gas chromatography and tandem mass spectrometry. In this strategy, tobacco samples were extracted with acetonitrile and cleaned up with a multilayer solid-phase extraction cartridge Cleanert TPT using acetonitrile/toluene (3:1) as the elution solvent. Two internal standards of different polarity were used to meet simultaneous pesticides quantification demands in the tobacco matrix. Satisfactory linearity in the range of 10-500 ng/mL was obtained for all 114 pesticides with linear regression coefficients higher than 0.994. The limit of detection and limit of quantification values were 0.02-5.27 and 0.06-17.6 ng/g, respectively. For most of the pesticides, acceptable recoveries in the range of 70-120% and repeatabilities (relative standard deviation) of <11% were achieved at spiking levels of 20, 100, and 400 ng/g. Compared with the reported multiresidue analytical method, the proposed method provided a cleaner test solution with smaller amounts of pigments, fatty acids as well as other undesirable interferences. The development and validation of the high sensitivity, high selectivity, easy automation, and high-throughput analytical method meant that it could be successfully used for the determination of pesticides in tobacco samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of short chain chlorinated paraffins in water by stir bar sorptive extraction-thermal desorption-gas chromatography-triple quadrupole tandem mass spectrometry.

PubMed

Tölgyessy, P; Nagyová, S; Sládkovičová, M

2017-04-21

A simple, robust, sensitive and environment friendly method for the determination of short chain chlorinated paraffins (SCCPs) in water using stir bar sorptive extraction (SBSE) coupled to thermal desorption-gas chromatography-triple quadrupole tandem mass spectrometry (TD-GC-QqQ-MS/MS) was developed. SBSE was performed using 100mL of water sample, 20mL of methanol as a modifier, and a commercial sorptive stir bar (with 10mm×0.5mm PDMS layer) during extraction period of 16h. After extraction, the sorptive stir bar was thermally desorbed and online analysed by GC-MS/MS. Method performance was evaluated for MilliQ and surface water spiked samples. For both types of matrices, a linear dynamic range of 0.5-3.0μgL -1 with correlation coefficients >0.999 and relative standard deviations (RSDs) of the relative response factors (RRFs) <12% was established. The limits of quantification (LOQs) of 0.06 and 0.08μgL -1 , and the precision (repeatability) of 6.4 and 7.7% (RSDs) were achieved for MilliQ and surface water, respectively. The method also showed good robustness, recovery and accuracy. The obtained performance characteristics indicate that the method is suitable for screening and monitoring and compliance checking with environmental quality standards (EQS, set by the EU) for SCCPs in surface waters. Copyright © 2017 Elsevier B.V. All rights reserved.

Development and Validation of HPLC Method for Determination of Crocetin, a constituent of Saffron, in Human Serum Samples.

PubMed

Mohammadpour, Amir Hooshang; Ramezani, Mohammad; Tavakoli Anaraki, Nasim; Malaekeh-Nikouei, Bizhan; Amel Farzad, Sara; Hosseinzadeh, Hossein

2013-01-01

The present study reports the development and validation of a sensitive and rapid extraction method beside high performance liquid chromatographic method for the determination of crocetin in human serum. The HPLC method was carried out by using a C18 reversed-phase column and a mobile phase composed of methanol/water/acetic acid (85:14.5:0.5 v/v/v) at the flow rate of 0.8 ml/min. The UV detector was set at 423 nm and 13-cis retinoic acid was used as the internal standard. Serum samples were pretreated with solid-phase extraction using Bond Elut C18 (200mg) cartridges or with direct precipitation using acetonitrile. The calibration curves were linear over the range of 0.05-1.25 µg/ml for direct precipitation method and 0.5-5 µg/ml for solid-phase extraction. The mean recoveries of crocetin over a concentration range of 0.05-5 µg/ml serum for direct precipitation method and 0.5-5 µg/ml for solid-phase extraction were above 70 % and 60 %, respectively. The intraday coefficients of variation were 0.37- 2.6% for direct precipitation method and 0.64 - 5.43% for solid-phase extraction. The inter day coefficients of variation were 1.69 - 6.03% for direct precipitation method and 5.13-12.74% for solid-phase extraction, respectively. The lower limit of quantification for crocetin was 0.05 µg/ml for direct precipitation method and 0.5 µg/ml for solid-phase extraction. The validated direct precipitation method for HPLC satisfied all of the criteria that were necessary for a bioanalytical method and could reliably quantitate crocetin in human serum for future clinical pharmacokinetic study.

Simultaneous determination of nine saponins from Panax notoginseng using HPLC and pressurized liquid extraction.

PubMed

Wan, J B; Lai, C M; Li, S P; Lee, M Y; Kong, L Y; Wang, Y T

2006-04-11

A HPLC and pressurized liquid extraction (PLE) method was developed for simultaneous determination of nine saponins, including notoginsenoside R1, ginsenoside Rg1, Re, Rf, Rb1, Rc, Rb2, Rb3 and Rd in Panax notoginseng. The analysis was performed on C18 column with water-acetonitrile gradient elution and the investigated saponins were authenticated by comparing retention time and mass spectra with their reference compounds. Several methods including PLE, ultrasonication, soxhlet extraction and immersion were used for sample preparation and their extraction efficiency was compared. The results showed that PLE has the highest extraction efficiency and repeatability, which would be valuable on standardization of sample preparation for quality control of Chinese medicines. The developed HPLC and PLE is an effective approach for simultaneously quantitative determination of sapoinins in P. notoginseng, which could be used for quality control of P. notoginseng and its preparations.

New feature extraction method for classification of agricultural products from x-ray images

NASA Astrophysics Data System (ADS)

Talukder, Ashit; Casasent, David P.; Lee, Ha-Woon; Keagy, Pamela M.; Schatzki, Thomas F.

1999-01-01

Classification of real-time x-ray images of randomly oriented touching pistachio nuts is discussed. The ultimate objective is the development of a system for automated non- invasive detection of defective product items on a conveyor belt. We discuss the extraction of new features that allow better discrimination between damaged and clean items. This feature extraction and classification stage is the new aspect of this paper; our new maximum representation and discrimination between damaged and clean items. This feature extraction and classification stage is the new aspect of this paper; our new maximum representation and discriminating feature (MRDF) extraction method computes nonlinear features that are used as inputs to a new modified k nearest neighbor classifier. In this work the MRDF is applied to standard features. The MRDF is robust to various probability distributions of the input class and is shown to provide good classification and new ROC data.

Physically incorporated extraction phase of solid-phase microextraction by sol-gel technology.

PubMed

Liu, Wenmin; Hu, Yuan; Zhao, Jinghong; Xu, Yuan; Guan, Yafeng

2006-01-13

A sol-gel method for the preparation of solid-phase microextraction (SPME) fiber was described and evaluated. The extraction phase of poly(dimethysiloxane) (PDMS) containing 3% vinyl group was physically incorporated into the sol-gel network without chemical bonding. The extraction phase itself is then partly crosslinked at 320 degrees C, forming an independent polymer network and can withstand desorption temperature of 290 degrees C. The headspace extraction of BTX by the fiber SPME was evaluated and the detection limit of o-xylene was down to 0.26 ng/l. Extraction and determination of organophosphorus pesticides (OPPs) in water, orange juice and red wine by the SPME-GC thermionic specified detector (TSD) was validated. Limits of detection of the method for OPPs were below 10 ng/l except methidathion. Relative standard deviations (RSDs) were in the range of 1-20% for pesticides being tested.

The ethanolic extract of ashitaba stem (Angelica keskei [Miq.] Koidz) as future antituberculosis

PubMed Central

Kusuma, Sri Agung Fitri; Iskandar, Yoppi; Dewanti, Mutiara Ayu

2018-01-01

Considering the easy contagion of tuberculosis (TB) disease spread and the emergence of multidrug-resistant TB, which directly impacts the failure of therapeutic goals and mortality rates increasing, TB disease control remains to be the main concern of continuous health development effort. Therefore, the discovery of new TB drug is needed. This research assessed the new natural anti-TB drug from the ethanolic extract of Angelica keiskei stem obtained from Lombok, Indonesia. The objectives of this study were to evaluate the sensitivity of Mycobacterium tuberculosis (Mtb) H37Rv strain to A. keiskei stem extract and to determine its minimum inhibitory concentration (MIC). The extraction methods of A. keiskei stem were done using a maceration method. In addition to phytochemical screening and water content analysis using standard method, the phytochemical parameters were analyzed by thin-layer chromatography. Ethanolic extract of A. keiskei stem was assayed for their Mtb inhibitory activity using the proportion method. The phytochemical analysis result showed that the secondary metabolites contain in the extract were flavonoid, polyphenol, tannin, monoterpenoid and sesquiterpen, quinon, and saponin. The anti-TB test result showed the active activity of ethanolic extract of A. keiskei against Mtb H37Rv strain with MIC ranging from 6% to 8% w/v. In conclusion, ethanolic extract of A. keiskei is a prospective natural anti-TB for the future. PMID:29441323

Evaluation of anti-inflammatory activity of Vernonia cinerea Less. extract in rats.

PubMed

Mazumder, U K; Gupta, M; Manikandan, L; Bhattacharya, S; Haldar, P K; Roy, S

2003-03-01

The methanol extract of the whole plant of Vernonia cinerea Less. was evaluated for its anti-inflammatory activity in acute (carrageenin, histamine and serotonin induced rat paw edema) and a chronic model (cotton pouch induced granuloma). The methanol extract (250 and 500 mg/kg(-1) p.o.) exhibited significant activity (p < 0.001) against all phlogistic agents used in a dose dependant manner. In the chronic model (cotton pouch granuloma method) the methanol extract exhibited significant anti-inflammatory activity. All these effects were compared with standard drug phenylbutazone (100 mg/kg(-1) p.o.).

The Agent of extracting Internet Information with Lead Order

NASA Astrophysics Data System (ADS)

Mo, Zan; Huang, Chuliang; Liu, Aijun

In order to carry out e-commerce better, advanced technologies to access business information are in need urgently. An agent is described to deal with the problems of extracting internet information that caused by the non-standard and skimble-scamble structure of Chinese websites. The agent designed includes three modules which respond to the process of extracting information separately. A method of HTTP tree and a kind of Lead algorithm is proposed to generate a lead order, with which the required web can be retrieved easily. How to transform the extracted information structuralized with natural language is also discussed.

Efficient method of protein extraction from Theobroma cacao L. roots for two-dimensional gel electrophoresis and mass spectrometry analyses.

PubMed

Bertolde, F Z; Almeida, A-A F; Silva, F A C; Oliveira, T M; Pirovani, C P

2014-07-04

Theobroma cacao is a woody and recalcitrant plant with a very high level of interfering compounds. Standard protocols for protein extraction were proposed for various types of samples, but the presence of interfering compounds in many samples prevented the isolation of proteins suitable for two-dimensional gel electrophoresis (2-DE). An efficient method to extract root proteins for 2-DE was established to overcome these problems. The main features of this protocol are: i) precipitation with trichloroacetic acid/acetone overnight to prepare the acetone dry powder (ADP), ii) several additional steps of sonication in the ADP preparation and extractions with dense sodium dodecyl sulfate and phenol, and iii) adding two stages of phenol extractions. Proteins were extracted from roots using this new protocol (Method B) and a protocol described in the literature for T. cacao leaves and meristems (Method A). Using these methods, we obtained a protein yield of about 0.7 and 2.5 mg per 1.0 g lyophilized root, and a total of 60 and 400 spots could be separated, respectively. Through Method B, it was possible to isolate high-quality protein and a high yield of roots from T. cacao for high-quality 2-DE gels. To demonstrate the quality of the extracted proteins from roots of T. cacao using Method B, several protein spots were cut from the 2-DE gels, analyzed by tandem mass spectrometry, and identified. Method B was further tested on Citrus roots, with a protein yield of about 2.7 mg per 1.0 g lyophilized root and 800 detected spots.

[Determination of four insecticide residues in honey and royal jelly by gas chromatography-negative chemical ionization mass spectrometry].

PubMed

Xia, Guanghui; Shen, Weijian; Yu, Keyao; Wu, Bin; Zhang, Rui; Shen, Chongyu; Zhao, Zengyun; Bian, Xiaohong; Xu, Jiyang

2014-07-01

A method was developed for the determination of four insecticide residues in honey and royal jelly by gas chromatography-negative chemical ionization mass spectrometry (GC-NCI/MS). The honey and royal jelly samples were treated with different preparation methods as the result of the different components. The honey sample was extracted with ethyl acetate and cleaned up with primary second amine, and the royal jelly sample was extracted with acetonitrile-water (1:1, v/v), and cleaned up with a C18 solid-phase extraction column. Finally, the extracts of the honey and royal jelly were analyzed by GC-NCI/MS in selected ion monitoring (SIM) mode separately. External standard calibration method was used for quantification. The linearities of calibration curves of the four insecticides were good with the correlation coefficients greater than 0.99 in the range of 50-500 microg/L. The limits of the detection (LODs) of the four insecticides were in the range of 0.12- 5.0 microg/kg, and the limits of the quantification (LOQs) were in the range of 0.40-16.5 microg/kg. The recoveries of the four insecticides spiked in honey and royal jelly at three spiked levels (10, 15 and 20 microg/kg) were in the range of 78.2 -110.0%, and the relative standard deviations (RSDs) were all below 14%. The sensitivity and selectivity of this method were good with no interfering peaks. The proposed method is simple quick and effective to analyze the four insecticide residues in honey and royal jelly.

Determination of terpenoid content in pine by organic solvent extraction and fast-GC analysis

DOE PAGES

Harman-Ware, Anne E.; Sykes, Robert; Peter, Gary F.; ...

2016-01-25

Terpenoids, naturally occurring compounds derived from isoprene units present in pine oleoresin, are a valuable source of chemicals used in solvents, fragrances, flavors, and have shown potential use as a biofuel. This paper describes a method to extract and analyze the terpenoids present in loblolly pine saplings and pine lighter wood. Various extraction solvents were tested over different times and temperatures. Samples were analyzed by pyrolysis-molecular beam mass spectrometry before and after extractions to monitor the extraction efficiency. The pyrolysis studies indicated that the optimal extraction method used a 1:1 hexane/acetone solvent system at 22°C for 1 h. Extracts frommore » the hexane/acetone experiments were analyzed using a low thermal mass modular accelerated column heater for fast-GC/FID analysis. The most abundant terpenoids from the pine samples were quantified, using standard curves, and included the monoterpenes, α- and β-pinene, camphene, and δ-carene. Sesquiterpenes analyzed included caryophyllene, humulene, and α-bisabolene. In conclusion, diterpenoid resin acids were quantified in derivatized extractions, including pimaric, isopimaric, levopimaric, palustric, dehydroabietic, abietic, and neoabietic acids.« less

Extractive colorimetric method for the determination of dothiepin hydrochloride and risperidone in pure and in dosage forms.

PubMed

Hassan, Wafaa El-Sayed

2008-08-01

Three rapid, simple, reproducible and sensitive extractive colorimetric methods (A--C) for assaying dothiepin hydrochloride (I) and risperidone (II) in bulk sample and in dosage forms were investigated. Methods A and B are based on the formation of an ion pair complexes with methyl orange (A) and orange G (B), whereas method C depends on ternary complex formation between cobalt thiocyanate and the studied drug I or II. The optimum reaction conditions were investigated and it was observed the calibration curves resulting from the measurements of absorbance concentration relations of the extracted complexes were linear over the concentration range 0.1--12 microg ml(-1) for method A, 0.5--11 mug ml(-1) for method B, and 3.2--80 microg ml(-1) for method C with a relative standard deviation (RSD) of 1.17 and 1.28 for drug I and II, respectively. The molar absorptivity, Sandell sensitivity, Ringbom optimum concentration ranges, and detection and quantification limits for all complexes were calculated and evaluated at maximum wavelengths of 423, 498, and 625 nm, using methods A, B, and C, respectively. The interference from excipients commonly present in dosage forms and common degradation products was studied. The proposed methods are highly specific for the determination of drugs I and II, in their dosage forms applying the standard additions technique without any interference from common excipients. The proposed methods have been compared statistically to the reference methods and found to be simple, accurate (t-test) and reproducible (F-value).

Methods of analysis-Determination of pesticides in sediment using gas chromatography/mass spectrometry

USGS Publications Warehouse

Hladik, Michelle; McWayne, Megan M.

2012-01-01

A method for the determination of 119 pesticides in environmental sediment samples is described. The method was developed by the U.S. Geological Survey (USGS) in support of the National Water Quality Assessment (NAWQA) Program. The pesticides included in this method were chosen through prior prioritization. Herbicides, insecticides, and fungicides along with degradates are included in this method and span a variety of chemical classes including, but not limited to, chloroacetanilides, organochlorines, organophosphates, pyrethroids, triazines, and triazoles. Sediment samples are extracted by using an accelerated solvent extraction system (ASE®, and the compounds of interest are separated from co-extracted matrix interferences (including sulfur) by passing the extracts through high performance liquid chromatography (HPLC) with gel-permeation chromatography (GPC) along with the use of either stacked graphitized carbon and alumina solid-phase extraction (SPE) cartridges or packed Florisil®. Chromatographic separation, detection, and quantification of the pesticides from the sediment-sample extracts are done by using gas chromatography with mass spectrometry (GC/MS). Recoveries in test sediment samples fortified at 10 micrograms per kilogram (μg/kg) dry weight ranged from 75 to 102 percent; relative standard deviations ranged from 3 to 13 percent. Method detection limits (MDLs), calculated by using U.S. Environmental Protection Agency procedures (40 CFR 136, Appendix B), ranged from 0.6 to 3.4 μg/kg dry weight.

[Comparison of two algorithms for development of design space-overlapping method and probability-based method].

PubMed

Shao, Jing-Yuan; Qu, Hai-Bin; Gong, Xing-Chu

2018-05-01

In this work, two algorithms (overlapping method and the probability-based method) for design space calculation were compared by using the data collected from extraction process of Codonopsis Radix as an example. In the probability-based method, experimental error was simulated to calculate the probability of reaching the standard. The effects of several parameters on the calculated design space were studied, including simulation number, step length, and the acceptable probability threshold. For the extraction process of Codonopsis Radix, 10 000 times of simulation and 0.02 for the calculation step length can lead to a satisfactory design space. In general, the overlapping method is easy to understand, and can be realized by several kinds of commercial software without coding programs, but the reliability of the process evaluation indexes when operating in the design space is not indicated. Probability-based method is complex in calculation, but can provide the reliability to ensure that the process indexes can reach the standard within the acceptable probability threshold. In addition, there is no probability mutation in the edge of design space by probability-based method. Therefore, probability-based method is recommended for design space calculation. Copyright© by the Chinese Pharmaceutical Association.

Determination of a metabolite of nifursol in foodstuffs of animal origin by liquid-liquid extraction and liquid chromatography with tandem mass spectrometry.

PubMed

Wang, Chuanxian; Qu, Li; Liu, Xia; Zhao, Chaomin; Zhao, Fengjuan; Huang, Fuzhen; Zhu, Zhenou; Han, Chao

2017-02-01

An analytical method has been developed for the detection of a metabolite of nifursol, 3,5-dinitrosalicylic acid hydrazide, in foodstuffs of animal origin (chicken liver, pork liver, lobster, shrimp, eel, sausage, and honey). The method combines liquid chromatography and tandem mass spectrometry with liquid-liquid extraction. Samples were hydrolyzed with hydrochloric acid and derivatized with 2-nitrobenzaldehyde at 37°C for 16 h. The solutions of derivatives were adjusted to pH 7.0-7.5, and the metabolite was extracted with ethyl acetate. 3,5-Dinitrosalicylic acid hydrazide determination was performed in the negative electrospray ionization method. Both isotope-labeled internal standard and matrix-matched calibration solutions were used to correct the matrix effects. Limits of quantification were 0.5 μg/kg for all samples. The average recoveries, measured at three concentration levels (0.5, 2.0, and 10 μg/kg) were in the range of 75.8-108.4% with relative standard deviations below 9.8%. The developed method exhibits a high sensitivity and selectivity for the routine determination and confirmation of the presence of a metabolite of nifursol in foodstuffs of animal origin. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Novel and Rapid Method to Determine Doxycycline in Human Plasma by Liquid Chromatography Tandem Mass Spectrometry

PubMed Central

Krishna, A. Chaitanya; Sathiyaraj, M.; Saravanan, R. S.; Chelladurai, R.; Vignesh, R.

2012-01-01

A simple, rapid, specific and sensitive liquid chromatography tandem mass spectrometric method has been developed and validated for the determination of doxycycline from the human plasma. Doxycycline is extracted from human plasma by solid phase extraction. Demeclocycline was used as an internal standard. Detection was performed at transitions of 444.800→428.200 for doxycycline and 464.700→448.100 for demeclocycline using mass spectrometry. Chromatographic separation of analyte and internal standard were carried out using a reverse phase C18, column at 0.500 ml/min flow. The assay of doxycycline is linear over the range of 0.055-7.612 μg/ml, with a precision <14.83%, regression coefficient (r2)=0.9961 and the limit of quantification in plasma for doxycycline was 0.055 μg/ml. Mean extraction recovery obtained was 95.55%. Samples are stable at room temperature for 6 h, processed samples were stable at least for 30.20 h and also stable at three freeze-thaw cycles. The method has been used to perform pharmacokinetic and bioequivalence studies in human plasma. PMID:23798780

Direct Analysis of Low-Volatile Molecular Marker Extract from Airborne Particulate Matter Using Sensitivity Correction Method

PubMed Central

Irei, Satoshi

2016-01-01

Molecular marker analysis of environmental samples often requires time consuming preseparation steps. Here, analysis of low-volatile nonpolar molecular markers (5-6 ring polycyclic aromatic hydrocarbons or PAHs, hopanoids, and n-alkanes) without the preseparation procedure is presented. Analysis of artificial sample extracts was directly conducted by gas chromatography-mass spectrometry (GC-MS). After every sample injection, a standard mixture was also analyzed to make a correction on the variation of instrumental sensitivity caused by the unfavorable matrix contained in the extract. The method was further validated for the PAHs using the NIST standard reference materials (SRMs) and then applied to airborne particulate matter samples. Tests with the SRMs showed that overall our methodology was validated with the uncertainty of ~30%. The measurement results of airborne particulate matter (PM) filter samples showed a strong correlation between the PAHs, implying the contributions from the same emission source. Analysis of size-segregated PM filter samples showed that their size distributions were found to be in the PM smaller than 0.4 μm aerodynamic diameter. The observations were consistent with our expectation of their possible sources. Thus, the method was found to be useful for molecular marker studies. PMID:27127511

Determination of Aroclor 1260 in soil samples by gas chromatography with mass spectrometry and solid-phase microextraction.

PubMed

Zhang, Mengliang; Jackson, Glen P; Kruse, Natalie A; Bowman, Jennifer R; Harrington, Peter de B

2014-10-01

A novel fast screening method was developed for the determination of polychlorinated biphenyls that are constituents of the commercial mixture, Aroclor 1260, in soil matrices by gas chromatography with mass spectrometry combined with solid-phase microextraction. Nonequilibrium headspace solid-phase microextraction with a 100 μm polydimethylsiloxane fiber was used to extract polychlorinated biphenyls from 0.5 g of soil matrix. The use of 2 mL of saturated potassium dichromate in 6 M sulfuric acid solution improved the reproducibility of the extractions and the mass transfer of the polychlorinated biphenyls from the soil matrix to the microextraction fiber via the headspace. The extraction time was 30 min at 100°C. The percent recoveries, which were evaluated using an Aroclor 1260 standard and liquid injection, were within the range of 54.9-65.7%. Two-way extracted ion chromatogram data were used to construct calibration curves. The relative error was <±15% and the relative standard deviation was <15%, which are respective measures of the accuracy and precision. The method was validated with certified soil samples and the predicted concentrations for Aroclor 1260 agreed with the certified values. The method was demonstrated to be linear from 10 to 1000 ng/g for Aroclor 1260 in dry soil. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Application of Stir Bar Sorptive Extraction and Gas Chromatograph Mass Spectrometer to the Phthalic Acid Esters Analysis in Seawater].

PubMed

Gao, Chen-chen; Li, Feng-min; Lu, Lun; Sun, Yue

2015-10-01

For the determination of trace amounts of phthalic acid esters (PAEs) in complex seawater matrix, a stir bar sorptive extraction gas chromatography mass spectrometry (SBSE-GC-MS) method was established. Dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), dibutyl phthalate (2-ethylhexyl) phthalate (DEHP) and dioctyl phthalate (DOP) were selected as study objects. The effects of extraction time, amount of methanol, amount of sodium chloride, desorption time and desorption solvent were optimized. The method of SBSE-GC-MS was validated through recoveries and relative standard deviation. The optimal extraction time was 2 h. The optimal methanol content was 10%. The optimal sodium chloride content was 5% . The optimal desorption time was 50 min. The optimal desorption solvent was the mixture of methanol to acetonitrile (4:1, volume: volume). The linear relationship between the peak area and the concentration of PAEs was relevant. The correlation coefficients were greater than 0.997. The detection limits were between 0.25 and 174.42 ng x L(-1). The recoveries of different concentrations were between 56.97% and 124.22% . The relative standard deviations were between 0.41% and 14.39%. On the basis of the method, several estuaries water sample of Jiaozhou Bay were detected. DEP was detected in all samples, and the concentration of BBP, DEHP and DOP were much higher than the rest.

Simultaneous detection of nine cyanotoxins in drinking water using dual solid-phase extraction and liquid chromatography-mass spectrometry.

PubMed

Yen, Hung-Kai; Lin, Tsair-Fuh; Liao, Pao-Chi

2011-08-01

A solid-phase extraction (SPE)-liquid chromatography (LC)-mass spectrometry (MS) method was developed to concentrate and detect nine cyanotoxins simultaneously, including six microcystins (MCs) congeners, nodularin (NOD), anatoxin-a (ATX) and cylindrospermopsin (CYN), in pure and natural waters. A dual cartridge SPE assembly was tested for the operating parameters of cyanotoxin extraction. A surrogate standard (SS), 1,9-diaminononane, was spiked in all the samples before the SPE extraction, and an internal standard (IS), 2,3,5-trimethylphenyl methyl carbamate, was spiked before LC/MS analysis. The method detection limit (MDL) was 2-100 ng/L for nine cyanotoxins in pure water and was increased by a factor of three to ten in a more complicated water matrix. The recoveries based on SS were between 83 and 104%, while those based on IS were 80-120%. The developed method was successfully employed in analyzing 33 water samples collected from eutrophic lakes, water treatment plants and distribution taps. MCs, NOD, and CYN were detected in the reservoir water, with concentrations as high as 36 μg/L. In addition, for the first time in Taiwan's tap water, CYN was detected at concentrations as high as 8.6 μg/L. Quality control data for the field samples shows that the analytical scheme developed is appropriate for monitoring cyanotoxins. Copyright © 2011 Elsevier Ltd. All rights reserved.

Determination of Flavonol Aglycones in Ginkgo biloba Dietary Supplement Crude Materials and Finished Products by High-Performance Liquid Chromatography: Single Laboratory Validation

PubMed Central

Gray, Dean; LeVanseler, Kerri; Pan, Meide

2008-01-01

A single laboratory validation (SLV) was completed for a method to determine the flavonol aglycones quercetin, kaempferol, and isorhamnetin in Ginkgo biloba products. The method calculates total glycosides based on these aglycones formed following acid hydrolysis. Nine matrixes were chosen for the study, including crude leaf material, standardized dry powder extract, single and multiple entity finished products, and ethanol and glycerol tinctures. For the 9 matrixes evaluated as part of this SLV, the method appeared to be selective and specific, with no observed interferences. The simplified 60 min oven heating hydrolysis procedure was effective for each of the matrixes studied, with no apparent or consistent differences between 60, 75, and 90 min at 90°C. A Youden ruggedness trial testing 7 factors with the potential to affect quantitative results showed that 2 factors (volume hydrolyzed and test sample extraction/hydrolysis weight) were the most important parameters for control during sample preparation. The method performed well in terms of precision, with 4 matrixes tested in triplicate over a 3-day period showing an overall repeatability (relative standard deviation, RSD) of 2.3%. Analysis of variance testing at α = 0.05 showed no significant differences among the within- or between-group sources of variation, although comparisons of within-day (Sw), between-day (Sb), and total (St) precision showed that a majority of the standard deviation came from within-day determinations for all matrixes. Accuracy testing at 2 levels (approximately 30 and 90% of the determined concentrations in standardized dry powder extract) from 2 complex negative control matrixes showed an overall 96% recovery and RSD of 1.0% for the high spike, and 94% recovery and RSD of 2.5% for the low spike. HorRat scores were within the limits for performance acceptability, ranging from 0.4 to 1.3. Based on the performance results presented herein, it is recommended that this method progress to the collaborative laboratory trial. PMID:16001841

Determination of the phenoxyacid herbicides MCPA, mecoprop and 2,4-D in kidney tissue using liquid chromatography with electrospray tandem mass spectrometry.

PubMed

Charlton, Andrew J A; Stuckey, Vicki; Sykes, Mark D

2009-06-01

An analytical method was developed to determine the phenoxyacid herbicides 2,4-D, MCPA and mecoprop in kidney tissue from animals where poisoning is suspected. Samples were Soxhlet extracted using diethyl ether and the extracts cleaned-up using anion exchange solid phase extraction cartridges. Analysis was performed using liquid chromatography with negative-ion electrospray tandem mass spectrometry (LC-MS/MS). The method was evaluated by analysing control kidney samples fortified at 1 and 5 mg/kg. Mean recoveries ranged from 82 to 93% with relative standard deviations from 3.2 to 19%. The limit of detection was estimated to be 0.02 mg/kg.

Modifications to EPA Method 3060A to Improve Extraction of Cr(VI) from Chromium Ore Processing Residue-Contaminated Soils

USGS Publications Warehouse

Mills, Christopher T.; Bern, Carleton R.; Wolf, Ruth E.; Foster, Andrea L.; Morrison, Jean M.; Benzel, William M.

2017-01-01

It has been shown that EPA Method 3060A does not adequately extract Cr(VI) from chromium ore processing residue (COPR). We modified various parameters of EPA 3060A toward understanding the transformation of COPR minerals in the alkaline extraction and improving extraction of Cr(VI) from NIST SRM 2701, a standard COPR-contaminated soil. Aluminum and Si were the major elements dissolved from NIST 2701, and their concentrations in solution were correlated with Cr(VI). The extraction fluid leached additional Al and Si from the method-prescribed borosilicate glass vessels which appeared to suppress the release of Cr(VI). Use of polytetrafluoroethylene vessels and intensive grinding of NIST 2701 increased the amount of Cr(VI) extracted. These modifications, combined with an increased extraction fluid to sample ratio of ≥900 mL g–1 and 48-h extraction time resulted in a maximum release of 1274 ± 7 mg kg–1 Cr(VI). This is greater than the NIST 2701 certified value of 551 ± 35 mg kg–1 but less than 3050 mg kg–1 Cr(VI) previously estimated by X-ray absorption near edge structure spectroscopy. Some of the increased Cr(VI) may have resulted from oxidation of Cr(III) released from brownmillerite which rapidly transformed during the extractions. Layered-double hydroxides remained stable during extractions and represent a potential residence for unextracted Cr(VI).

Superparamagnetic graphene oxide-based dispersive-solid phase extraction for preconcentration and determination of tamsulosin hydrochloride in human plasma by high performance liquid chromatography-ultraviolet detection.

PubMed

Pashaei, Yaser; Ghorbani-Bidkorbeh, Fatemeh; Shekarchi, Maryam

2017-05-26

In the present study, superparamagnetic graphene oxide-Fe 3 O 4 nanocomposites were successfully prepared by a modified impregnation method (MGO mi ) and their application as a sorbent in the magnetic-dispersive solid phase extraction (M-dSPE) mode to the preconcentration and determination of tamsulosin hydrochloride (TMS) in human plasma was investigated by coupling with high performance liquid chromatography-ultraviolet detection (HPLC-UV). The structure, morphology and magnetic properties of the prepared nanocomposites were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and vibrating sample magnetometry (VSM). Some factors affecting the extraction efficiency, including the pH value, amount of sorbent, extraction time, elution solvent and its volume, and desorption time were studied and optimized. Magnetic nanocomposites plasma extraction of TMS following HPLC analyses showed a linear calibration curve in the range of 0.5-50.0ngmL -1 with an acceptable correlation coefficient (R 2 =0.9988). The method was sensitive, with a low limit of detection (0.17ngmL -1 ) and quantification (0.48ngmL -1 ). Inter- and intra-day precision expressed as relative standard deviation (n=3) and the preconcentration factor, were found to be 5.6-7.2%, 2.9-4.2% and 10, respectively. Good recoveries (98.1-101.4%) with low relative standard deviations (4.2-5.0%) indicated that the matrices under consideration do not significantly affect the extraction process. Due to its high precision and accuracy, the developed method may be a HPLC-UV alternative with M-dSPE for bioequivalence analysis of TMS in human plasma. Copyright © 2017 Elsevier B.V. All rights reserved.

[Gas chromatography for analysis of essential oils. Characteristics of essential oil of Dracocephalum species and the influence of extraction method on its composition].

PubMed

Lemberkovics, Eva; Kakasy, András Zoltán; Héthelyi, B Eva; Simándi, Béla; Böszörményi, Andrea; Balázs, Andrea; Szoke, Eva

2007-01-01

In this work the essential oil composition of some less known Dracocephalum species was studied and compared the effectiveness, selectivity and influence of different extraction methods (hydrodistillation, Soxhlet extraction with organic solvents and supercritical fluid extraction) on essential oils. For investigations in Hungary and Transylvania cultivated plant material was used. The analysis of essential oils was carried out by GC and GC-MS methods. The components were identified by standard addition, retention factors and mass spectra. The percentile evaluation of each volatile constituents was made on basis of GC-FID chromatograms. The accuracy of measurements was characterized by relative standard deviation. In the essential oil of D. renati Emb. (studied firstly by us) 18.3% of limonene was measured and carvone, citrals and linalyl acetate monoterpenes, methyl chavicol and some sesquiterpene (e.g. bicyclovetivenol) determined in lower quantities. We established that more than 50% of essential oil of D. grandiflorum L. was formed by sesquiterpenes (beta-caryophyllene and- oxide, beta-bourbonene, beta-cubebene, aromadendrene) and the essential oil of D. ruyschiana L. contained pinocamphone isomers in more than 60%. The oxygenated acyclic monoterpenes, the characteristic constituents of Moldavian dragonhead were present in some tenth percent only in D. renati oil. We found significant differences in the composition of the SFE extract and traditional essential oil of D. moldavica L. The supercritical fractions collected at the beginning of the extraction process were richer in valuable ester component (geranyl acetate) than the essential oil obtained by hydrodistillation. The fractions collected at the end of supercritical were poor in oxygenated monoterpenes but rich in minor compounds of traditional oil, e.g. palmitic acid.

Comparison of accelerated solvent extraction and quick, easy, cheap, effective, rugged and safe method for extraction and determination of pharmaceuticals in vegetables.

PubMed

Chuang, Ya-Hui; Zhang, Yingjie; Zhang, Wei; Boyd, Stephen A; Li, Hui

2015-07-24

Land application of biosolids and irrigation with reclaimed water in agricultural production could result in accumulation of pharmaceuticals in vegetable produce. To better assess the potential human health impact from long-term consumption of pharmaceutical-contaminated vegetables, it is important to accurately quantify the amount of pharmaceuticals accumulated in vegetables. In this study, a quick, easy, cheap, effective, rugged and safe (QuEChERS) method was developed and optimized to extract multiple classes of pharmaceuticals from vegetables, which were subsequently quantified by liquid chromatography coupled to tandem mass spectrometry. For the eleven target pharmaceuticals in celery and lettuce, the extraction recovery of the QuEChERS method ranged from 70.1 to 118.6% with relative standard deviation <20%, and the method detection limit was achieved at the levels of nanograms of pharmaceuticals per gram of vegetables. The results revealed that the performance of the QuEChERS method was comparable to, or better than that of accelerated solvent extraction (ASE) method for extraction of pharmaceuticals from plants. The two optimized extraction methods were applied to quantify the uptake of pharmaceuticals by celery and lettuce growing hydroponically. The results showed that all the eleven target pharmaceuticals could be absorbed by the vegetables from water. Compared to the ASE method, the QuEChERS method offers the advantages of short time and reduced costs of sample preparation, and less amount of organic solvents used. The established QuEChERS method could be used to determine the accumulation of multiple classes of pharmaceutical residues in vegetables and other plants, which is needed to evaluate the quality and safety of agricultural produce consumed by humans. Copyright © 2015 Elsevier B.V. All rights reserved.

Determination of n-alkanes in C. annuum (bell pepper) fruit and seed using GC-MS: comparison of extraction methods and application to samples of different geographical origin.

PubMed

de Rijke, E; Fellner, C; Westerveld, J; Lopatka, M; Cerli, C; Kalbitz, K; de Koster, C G

2015-07-01

An efficient extraction and analysis method was developed for the isolation and quantification of n-alkanes from bell peppers of different geographical locations. Five extraction techniques, i.e., accelerated solvent extraction (ASE), ball mill extraction, ultrasonication, rinsing, and shaking, were quantitatively compared using gas chromatography coupled to mass spectrometry (GC-MS). Rinsing of the surface wax layer of freeze-dried bell peppers with chloroform proved to be a relatively quick and easy method to efficiently extract the main n-alkanes C27, C29, C31, and C33. A combined cleanup and fractionation approach on Teflon-coated silica SPE columns resulted in clean chromatograms and gave reproducible results (recoveries 90-95 %). The GC-MS method was reproducible (R(2) = 0.994-0.997, peak area standard deviation = 2-5%) and sensitive (LODs, S/N = 3, 0.05-0.15 ng/μL). The total main n-alkane concentrations were in the range of 5-50 μg/g dry weight. Seed extractions resulted in much lower total amounts of extracted n-alkanes compared to flesh and surface extractions, demonstrating the need for further improvement of pre-concentration and cleanup. The method was applied to 131 pepper samples from four different countries, and by using the relative n-alkane concentration ratios, Dutch peppers could be discriminated from those of the other countries, with the exception of peppers from the same cultivar. Graphical Abstract Procedure for pepper origin determination.

Extraction and Determination of Cyproheptadine in Human Urine by DLLME-HPLC Method.

PubMed

Maham, Mehdi; Kiarostami, Vahid; Waqif-Husain, Syed; Abroomand-Azar, Parviz; Tehrani, Mohammad Saber; Khoeini Sharifabadi, Malihe; Afrouzi, Hossein; Shapouri, Mahmoudreza; Karami-Osboo, Rouhollah

2013-01-01

Novel dispersive liquid-liquid microextraction (DLLME), coupled with high performance liquid chromatography with photodiode array detection (HPLC-DAD) has been applied for the extraction and determination of cyproheptadine (CPH), an antihistamine, in human urine samples. In this method, 0.6 mL of acetonitrile (disperser solvent) containing 30 μL of carbon tetrachloride (extraction solvent) was rapidly injected by a syringe into 5 mL urine sample. After centrifugation, the sedimented phase containing enriched analyte was dissolved in acetonitrile and an aliquot of this solution injected into the HPLC system for analysis. Development of DLLME procedure includes optimization of some important parameters such as kind and volume of extraction and disperser solvent, pH and salt addition. The proposed method has good linearity in the range of 0.02-4.5 μg mL(-1) and low detection limit (13.1 ng mL(-1)). The repeatability of the method, expressed as relative standard deviation was 4.9% (n = 3). This method has also been applied to the analysis of real urine samples with satisfactory relative recoveries in the range of 91.6-101.0%.

Antibacterial and antioxidant properties of the methanol extracts of the leaves and stems of Calpurnia aurea

PubMed Central

Adedapo, Adeolu A; Jimoh, Florence O; Koduru, Srinivas; Afolayan, Anthony J; Masika, Patrick J

2008-01-01

Background In South Africa, Calpurnia aurea (Ait.) Benth is used to destroy lice and to relieve itches, to destroy maggots and to treat allergic rashes, particularly those caused by caterpillars. Antioxidants play an important role protecting against damage by reactive oxygen species. Plants containing flavonoids have been reported to possess strong antioxidant properties. Methods The antibacterial, antioxidant activities and phenolic contents of the methanol extracts of the leaves and stems of Calpurnia aurea were evaluated using in vitro standard methods. Spectrophotometry was the basis for the determinations of total phenol, total flavonoids, flavonols, and proanthocyanidins. Tannins, quercetin and catechin equivalents were used for these parameters. The antioxidant activities of the stem extract of Calpurnia aurea were determined by ABTS, DPPH, and ferrous reducing antioxidant property (FRAP) methods. Laboratory isolates of 10 bacteria species which included five Gram-positive and five Gram-negative strains were used to assay for antibacterial activity of this plant. Results The results from this study showed that the antioxidant activities of the stem extract of Calpurnia aurea as determined by the total phenol, flavonoids, and FRAP methods were higher than that of the leaves. On the other hand, the leaf extract of the plant has higher level of total flavonols and proanthocyanidins. The leaf extract also has higher radical scavenging activity as shown in 1, 1-Diphenyl-2-picrylhydrazyl (DPPH), and 2,2¿-azinobis-3- ethylbenzothiazoline-6-sulfonic acid (ABTS) assay. The leaf extract showed activity against seven of the bacterial organisms. Conclusion The results from this study indicate that the leaves and stem extracts of Calpurnia aurea possess antioxidant properties and could serve as free radical inhibitors or scavenger or, acting possibly as primary antioxidants. Although, the antibacterial properties of Calpurnia aurea are not as effective as the standard drugs- Chloramphenicol and Streptomycin, they still possess some activity against bacterial strains used in this study. Calpurnia aurea may therefore be a good candidate for functional foods as well as pharmaceutical plant-based products. PMID:18803865

Total milk fat extraction and quantification of polar and neutral lipids of cow, goat, and ewe milk by using a pressurized liquid system and chromatographic techniques.

PubMed

Castro-Gómez, M P; Rodriguez-Alcalá, L M; Calvo, M V; Romero, J; Mendiola, J A; Ibañez, E; Fontecha, J

2014-11-01

Although milk polar lipids such as phospholipids and sphingolipids located in the milk fat globule membrane constitute 0.1 to 1% of the total milk fat, those lipid fractions are gaining increasing interest because of their potential beneficial effects on human health and technological properties. In this context, the accurate quantification of the milk polar lipids is crucial for comparison of different milk species, products, or dairy treatments. Although the official International Organization for Standardization-International Dairy Federation method for milk lipid extraction gives satisfactory results for neutral lipids, it has important disadvantages in terms of polar lipid losses. Other methods using mixtures of solvents such as chloroform:methanol are highly efficient for extracting polar lipids but are also associated with low sample throughput, long time, and large solvent consumption. As an alternative, we have optimized the milk fat extraction yield by using a pressurized liquid extraction (PLE) method at different temperatures and times in comparison with those traditional lipid extraction procedures using 2:1 chloroform:methanol as a mixture of solvents. Comparison of classical extraction methods with the developed PLE procedure were carried out using raw whole milk from different species (cows, ewes, and goats) and considering fat yield, fatty acid methyl ester composition, triacylglyceride species, cholesterol content, and lipid class compositions, with special attention to polar lipids such as phospholipids and sphingolipids. The developed PLE procedure was validated for milk fat extraction and the results show that this method performs a complete or close to complete extraction of all lipid classes and in less time than the official and Folch methods. In conclusion, the PLE method optimized in this study could be an alternative to carry out milk fat extraction as a routine method. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Extraction and preconcentration of residual solvents in pharmaceuticals using dynamic headspace-liquid phase microextraction and their determination by gas chromatography-flame ionization detection.

PubMed

Farajzadeh, Mir Ali; Dehghani, Hamideh; Yadeghari, Adeleh; Khoshmaram, Leila

2017-02-01

The present study describes a microextraction and determination method for analyzing residual solvents in pharmaceutical products using dynamic headspace-liquid phase microextraction technique followed by gas chromatography-flame ionization detection. In this method dimethyl sulfoxide (μL level) placed into a GC liner-shaped extraction vessel is used as a collection/extraction solvent. Then the liner is exposed to the headspace of a vial containing the sample solution. The effect of different parameters influencing the microextraction procedure including collection/extraction solvent type and its volume, ionic strength, extraction time, extraction temperature and concentration of NaOH solution used in dissolving the studied pharmaceuticals are investigated and optimized. Under the optimum extraction conditions, the method showed wide linear ranges between 0.5 and 5000 mg L -1 . The other analytical parameters were obtained in the following ranges: enrichment factors 240-327, extraction recoveries 72-98% and limits of detection 0.1-0.8 mg L -1 in solution and 0.6-3.2 μg g -1 in solid. Relative standard deviations for the extraction of 100 mg L -1 of each analyte were obtained in the ranges of 4-7 and 5-8% for intra-day (n = 6) and inter-day (n = 4) respectively. Finally the target analytes were determined in different samples such as erythromycin, azithromycin, cefalexin, amoxicillin and co-amoxiclav by the proposed method. Copyright © 2016 John Wiley & Sons, Ltd.

Aptamer-functionalized Fe3 O4 magnetic nanoparticles as a solid-phase extraction adsorbent for the selective extraction of berberine from Cortex phellodendri.

PubMed

Jiang, Ling-Feng; Chen, Bo-Cheng; Chen, Ben; Li, Xue-Jian; Liao, Hai-Lin; Zhang, Wen-Yan; Wu, Lin

2017-07-01

The extraction adsorbent was fabricated by immobilizing the highly specific recognition and binding of aptamer onto the surface of Fe 3 O 4 magnetic nanoparticles, which not only acted as recognition elements to recognize and capture the target molecule berberine from the extract of Cortex phellodendri, but also could favor the rapid separation and purification of the bound berberine by using an external magnet. The developed solid-phase extraction method in this work was useful for the selective extraction and determination of berberine in Cortex phellodendri extracts. Various conditions such as the amount of aptamer-functionalized Fe 3 O 4 magnetic nanoparticles, extraction time, temperature, pH value, Mg 2+ concentration, elution time and solvent were optimized for the solid-phase extraction of berberine. Under optimal conditions, the purity of berberine extracted from Cortex phellodendri was as high as 98.7% compared with that of 4.85% in the extract, indicating that aptamer-functionalized Fe 3 O 4 magnetic nanoparticles-based solid-phase extraction method was very effective for berberine enrichment and separation from a complex herb extract. The applicability and reliability of the developed solid-phase extraction method were demonstrated by separating berberine from nine different concentrations of one Cortex phellodendri extract. The relative recoveries of the spiked solutions of all the samples were between 95.4 and 111.3%, with relative standard deviations ranging between 0.57 and 1.85%. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Application of PLE for the determination of essential oil components from Thymus vulgaris L.

PubMed

Dawidowicz, Andrzej L; Rado, Ewelina; Wianowska, Dorota; Mardarowicz, Marek; Gawdzik, Jan

2008-08-15

Essential plants, due to their long presence in human history, their status in culinary arts, their use in medicine and perfume manufacture, belong to frequently examined stock materials in scientific and industrial laboratories. Because of a large number of freshly cut, dried or frozen plant samples requiring the determination of essential oil amount and composition, a fast, safe, simple, efficient and highly automatic sample preparation method is needed. Five sample preparation methods (steam distillation, extraction in the Soxhlet apparatus, supercritical fluid extraction, solid phase microextraction and pressurized liquid extraction) used for the isolation of aroma-active components from Thymus vulgaris L. are compared in the paper. The methods are mainly discussed with regard to the recovery of components which typically exist in essential oil isolated by steam distillation. According to the obtained data, PLE is the most efficient sample preparation method in determining the essential oil from the thyme herb. Although co-extraction of non-volatile ingredients is the main drawback of this method, it is characterized by the highest yield of essential oil components and the shortest extraction time required. Moreover, the relative peak amounts of essential components revealed by PLE are comparable with those obtained by steam distillation, which is recognized as standard sample preparation method for the analysis of essential oils in aromatic plants.

Standardizing Imperata cylindrica--source material for quality allergen preparations.

PubMed

Bijli, Kaiser M; Singh, B P; Sridhara, Susheela; Gaur, S N; Arora, Naveen

2002-02-01

Tropical countries experience wide variations in daytime temperature and relative humidity. This affects the quality of the source material used for allergen extracts. The present study was undertaken to standardize the processing and preservation conditions of Imperata cylindrica grass pollen. I. cylindrica (Ic) inflorescence were freeze-dried, pollens sieved out and stored at -70 degrees C (IcA). Alternatively, the inflorescence were dried at room temperature and then at 37 degrees C, pollens sieved out and stored at 4 degrees C (IcB). The extracts prepared in PBS were analyzed in vivo by skin tests and in vitro by immunochemical methods. Reduced SDS-PAGE revealed 37 protein bands in IcA extract and 23 in IcB extract. IgE immunoblot with a pool of sera from Ic hypersensitive patients showed 30 allergenic bands in IcA and 14 in IcB. Immunoblot using anti-Ic rabbit sera revealed 33 antigenic bands in IcA and 22 in IcB. In both blots, the IcA extract exhibited sharp bands and the IcB extract exhibited diffuse bands. ELISA, ELISA inhibition and skin test procedures showed that IcA extracts had a higher potency than IcB extracts. Extracts prepared from -70 degrees C processed and preserved pollens (IcA) are allergenically more potent and contain a greater number of major and minor allergens than IcB extracts.

[Rapid determination of 40 pesticide residues in fruits using gas chromatography-mass spectrometry coupled with analyte protectants to compensate for matrix effects].

PubMed

Xu, Xiuli; Zhao, Haixiang; Li, Li; Liu, Hanxia; Ren, Heling; Zhong, Weike

2012-03-01

A gas chromatography-mass spectrometry (GC-MS) method was developed for the determination of 40 pesticides in fruits. The effects of adding analyte protectants were evaluated for compensating matrix effects and the impacts on the quantitative results. A new combination of analyte protectants - Polyethylene Glycol 400 (PEG 400) and olive oil combination, which can be dissolved in acetone, was used for the quantitative analysis. The pesticides were extracted from fruit samples with acetonitrile and the extracts were cleaned up using micro-solid phase extraction. A GC-MS method in selective ion monitoring (SIM) mode coupled with large volume injection was finally developed. Using the newly developed analyte protectant combination of PEG 400 and olive oil, a good linearity was obtained in the range of 1 - 200 microg/L with coefficients better than 0.99, and the detection limits were between 0.1 - 3.0 microg/L. The mean recoveries of the pesticides were 75% - 119% with the relative standard deviation values less than 16.6% except for dimethoate. The performance of the analyte protectants was compared with matrix-matched standards calibration curves in terms of quantitative accuracy. The results showed that the method of adding analyte protectants can replace the matrix-matched standard calibration, and can also reduce the sample pretreatment. When the devel- oped method was used for the analysis of apple, peache, orange, banana, grape and other fruit samples, a good matrix compensation effect was achieved, and thus effectively reduced the bad effects of the water-soluble agents to the gas chromatographic column.

Quantitative enzyme-linked immunosorbent assay for determination of polychlorinated biphenyls in environmental soil and sediment samples.

PubMed

Johnson, J C; Van Emon, J M

1996-01-01

An enzyme-linked immunosorbent assay (ELISA) for the quantitative determination of Aroclors 1242, 1248, 1254, and 1260 in soil and sediments was developed and its performance compared with that of gas chromatography (GC). The detection limits for Aroclors 1242 and 1248 in soil are 10.5 and 9 ng/g, respectively. The assay linear dynamic range is 50-1333 ng/g. Cross-reactivity of the assay with 37 structurally related potential cocontaminants in environmental soil samples was examined; none of the chlorinated anisoles, benzenes, or phenols exhibited >3% cross-reactivity, with <0.1% cross-reactivity being the norm. Soil spike recoveries of 107% and 104% were obtained for Aroclors 1242 and 1248, respectively, for a spike level of 5 mg/kg, with corresponding relative standard deviations of 14% and 17%. One hundred forty-eight environmental soil, sediment, and paper pulp samples, obtained from two EPA listed Superfund sites, were analyzed by ELISA and standard GC methods. Samples were extracted for ELISA analysis by shaking with methanol. Additional extractions of the same samples were performed either with supercritical carbon dioxide or by Soxhlet extraction with methanol. ELISA results for both the supercritical fluid and the Soxhlet extracts were in close agreement with the GC results, while the ELISA results for the methanol shake extracts were not. The data for the environmental samples demonstrated the capability of the ELISA to provide accurate results and reinforced the dependence of any detection method, including ELISA, on appropriate extraction procedures.

Extraction efficiency and implications for absolute quantitation of propranolol in mouse brain, liver and kidney thin tissue sections using droplet-based liquid microjunction surface sampling-HPLC ESI-MS/MS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kertesz, Vilmos; Weiskittel, Taylor M.; Vavek, Marissa

Currently, absolute quantitation aspects of droplet-based surface sampling for thin tissue analysis using a fully automated autosampler/HPLC-ESI-MS/MS system are not fully evaluated. Knowledge of extraction efficiency and its reproducibility is required to judge the potential of the method for absolute quantitation of analytes from thin tissue sections. Methods: Adjacent thin tissue sections of propranolol dosed mouse brain (10- μm-thick), kidney (10- μm-thick) and liver (8-, 10-, 16- and 24- μm-thick) were obtained. Absolute concentration of propranolol was determined in tissue punches from serial sections using standard bulk tissue extraction protocols and subsequent HPLC separations and tandem mass spectrometric analysis. Thesemore » values were used to determine propranolol extraction efficiency from the tissues with the droplet-based surface sampling approach. Results: Extraction efficiency of propranolol using 10- μm-thick brain, kidney and liver thin tissues using droplet-based surface sampling varied between ~45-63%. Extraction efficiency decreased from ~65% to ~36% with liver thickness increasing from 8 μm to 24 μm. Randomly selecting half of the samples as standards, precision and accuracy of propranolol concentrations obtained for the other half of samples as quality control metrics were determined. Resulting precision ( ±15%) and accuracy ( ±3%) values, respectively, were within acceptable limits. In conclusion, comparative quantitation of adjacent mouse thin tissue sections of different organs and of various thicknesses by droplet-based surface sampling and by bulk extraction of tissue punches showed that extraction efficiency was incomplete using the former method, and that it depended on the organ and tissue thickness. However, once extraction efficiency was determined and applied, the droplet-based approach provided the required quantitation accuracy and precision for assay validations. Furthermore, this means that once the extraction efficiency was calibrated for a given tissue type and drug, the droplet-based approach provides a non-labor intensive and high-throughput means to acquire spatially resolved quantitative analysis of multiple samples of the same type.« less

Cytotoxicity of Brazilian plant extracts against oral microorganisms of interest to dentistry.

PubMed

de Oliveira, Jonatas Rafael; de Castro, Vinicius Carlos; das Graças Figueiredo Vilela, Polyana; Camargo, Samira Esteves Afonso; Carvalho, Cláudio Antonio Talge; Jorge, Antonio Olavo Cardoso; de Oliveira, Luciane Dias

2013-08-15

With the emergence of strains resistant to conventional antibiotics, it is important to carry studies using alternative methods to control these microorganisms causing important infections, such as the use of products of plant origin that has demonstrated effective antimicrobial activity besides biocompatibility. Therefore, this study aimed to evaluate the antimicrobial activity of plant extracts of Equisetum arvense L., Glycyrrhiza glabra L., Punica granatum L. and Stryphnodendron barbatimam Mart. against Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus mutans, Candida albicans, Candida tropicalis, and Candida glabrata, and to analyze the cytotoxicity of these extracts in cultured murine macrophages (RAW 264.7). Antimicrobial activity of plant extracts was evaluated by microdilution method based on Clinical and Laboratory Standards Institute (CLSI), M7-A6 and M27-A2 standards. The cytotoxicity of concentrations that eliminated the microorganisms was evaluated by MTT colorimetric method and by quantification of proinflammatory cytokines (IL-1β and TNF-α) using ELISA. In determining the minimum microbicidal concentration, E. arvense L., P. granatum L., and S. barbatimam Mart. extracts at a concentration of 50 mg/mL and G. glabra L. extract at a concentration of 100 mg/mL, were effective against all microorganisms tested. Regarding cell viability, values were 48% for E. arvense L., 76% for P. granatum L, 86% for S. barbatimam Mart. and 79% for G. glabra L. at the same concentrations. About cytokine production after stimulation with the most effective concentrations of the extracts, there was a significant increase of IL-1β in macrophage cultures treated with S. barbatimam Mart. (3.98 pg/mL) and P. granatum L. (7.72 pg/mL) compared to control (2.20 pg/mL) and a significant decrease of TNF-α was observed in cultures treated with G. glabra L. (4.92 pg/mL), S. barbatimam Mart. (0.85 pg/mL), E. arvense L. (0.83 pg/mL), and P. granatum L. (0.00 pg/mL) when compared to control (41.96 pg/mL). All plant extracts were effective against the microorganisms tested. The G. glabra L. extract exhibited least cytotoxicity and the E. arvense L. extract was the most cytotoxic.

Extraction efficiency and implications for absolute quantitation of propranolol in mouse brain, liver and kidney thin tissue sections using droplet-based liquid microjunction surface sampling-HPLC ESI-MS/MS

DOE PAGES

Kertesz, Vilmos; Weiskittel, Taylor M.; Vavek, Marissa; ...

2016-06-22

Currently, absolute quantitation aspects of droplet-based surface sampling for thin tissue analysis using a fully automated autosampler/HPLC-ESI-MS/MS system are not fully evaluated. Knowledge of extraction efficiency and its reproducibility is required to judge the potential of the method for absolute quantitation of analytes from thin tissue sections. Methods: Adjacent thin tissue sections of propranolol dosed mouse brain (10- μm-thick), kidney (10- μm-thick) and liver (8-, 10-, 16- and 24- μm-thick) were obtained. Absolute concentration of propranolol was determined in tissue punches from serial sections using standard bulk tissue extraction protocols and subsequent HPLC separations and tandem mass spectrometric analysis. Thesemore » values were used to determine propranolol extraction efficiency from the tissues with the droplet-based surface sampling approach. Results: Extraction efficiency of propranolol using 10- μm-thick brain, kidney and liver thin tissues using droplet-based surface sampling varied between ~45-63%. Extraction efficiency decreased from ~65% to ~36% with liver thickness increasing from 8 μm to 24 μm. Randomly selecting half of the samples as standards, precision and accuracy of propranolol concentrations obtained for the other half of samples as quality control metrics were determined. Resulting precision ( ±15%) and accuracy ( ±3%) values, respectively, were within acceptable limits. In conclusion, comparative quantitation of adjacent mouse thin tissue sections of different organs and of various thicknesses by droplet-based surface sampling and by bulk extraction of tissue punches showed that extraction efficiency was incomplete using the former method, and that it depended on the organ and tissue thickness. However, once extraction efficiency was determined and applied, the droplet-based approach provided the required quantitation accuracy and precision for assay validations. Furthermore, this means that once the extraction efficiency was calibrated for a given tissue type and drug, the droplet-based approach provides a non-labor intensive and high-throughput means to acquire spatially resolved quantitative analysis of multiple samples of the same type.« less

Silica-based ionic liquid coating for 96-blade system for extraction of aminoacids from complex matrixes.

PubMed

Mousavi, Fatemeh; Pawliszyn, Janusz

2013-11-25

1-Vinyl-3-octadecylimidazolium bromide ionic liquid [C18VIm]Br was prepared and used for the modification of mercaptopropyl-functionalized silica (Si-MPS) through surface radical chain-transfer addition. The synthesized octadecylimidazolium-modified silica (SiImC18) was characterized by thermogravimetric analysis (TGA), infrared spectroscopy (IR), (13)C NMR and (29)Si NMR spectroscopy and used as an extraction phase for the automated 96-blade solid phase microextraction (SPME) system with thin-film geometry using polyacrylonitrile (PAN) glue. The new proposed extraction phase was applied for extraction of aminoacids from grape pulp, and LC-MS-MS method was developed for separation of model compounds. Extraction efficiency, reusability, linearity, limit of detection, limit of quantitation and matrix effect were evaluated. The whole process of sample preparation for the proposed method requires 270min for 96 samples simultaneously (60min preconditioning, 90min extraction, 60min desorption and 60min for carryover step) using 96-blade SPME system. Inter-blade and intra-blade reproducibility were in the respective ranges of 5-13 and 3-10% relative standard deviation (RSD) for all model compounds. Limits of detection and quantitation of the proposed SPME-LC-MS/MS system for analysis of analytes were found to range from 0.1 to 1.0 and 0.5 to 3.0μgL(-1), respectively. Standard addition calibration was applied for quantitative analysis of aminoacids from grape juice and the results were validated with solvent extraction (SE) technique. Copyright © 2013 Elsevier B.V. All rights reserved.

Quantitative PCR Method for Diagnosis of Citrus Bacterial Canker†

PubMed Central

Cubero, J.; Graham, J. H.; Gottwald, T. R.

2001-01-01

For diagnosis of citrus bacterial canker by PCR, an internal standard is employed to ensure the quality of the DNA extraction and that proper requisites exist for the amplification reaction. The ratio of PCR products from the internal standard and bacterial target is used to estimate the initial bacterial concentration in citrus tissues with lesions. PMID:11375206

High Performance Liquid Chromatography of Vitamin A: A Quantitative Determination.

ERIC Educational Resources Information Center

Bohman, Ove; And Others

1982-01-01

Experimental procedures are provided for the quantitative determination of Vitamin A (retinol) in food products by analytical liquid chromatography. Standard addition and calibration curve extraction methods are outlined. (SK)

40 CFR 63.2851 - What is a plan for demonstrating compliance?

Code of Federal Regulations, 2010 CFR

2010-07-01

... National Emission Standards for Hazardous Air Pollutants: Solvent Extraction for Vegetable Oil Production... of the vegetable oil production process. (3) A detailed description of all methods of measurement...

40 CFR 63.2851 - What is a plan for demonstrating compliance?

Code of Federal Regulations, 2011 CFR

2011-07-01

... National Emission Standards for Hazardous Air Pollutants: Solvent Extraction for Vegetable Oil Production... of the vegetable oil production process. (3) A detailed description of all methods of measurement...

NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR EXTRACTION OF AIR SAMPLES FOR GC/MS ANALYSIS OF PESTICIDE AND PAH (BCO-L-27.0)

EPA Science Inventory

The purpose of this SOP is to describe methods for extracting and preparing an air sample consisting of a quartz fiber filter (Pallflex) and an XAD-2 cartridge for analysis of pesticides and polyaromatic hydrocarbons (PAHs). It covers the preparation of samples that are to be an...

Method and apparatus for maintaining multi-component sample gas constituents in vapor phase during sample extraction and cooling

DOEpatents

Farthing, William Earl [Pinson, AL; Felix, Larry Gordon [Pelham, AL; Snyder, Todd Robert [Birmingham, AL

2008-02-12

An apparatus and method for diluting and cooling that is extracted from high temperature and/or high pressure industrial processes. Through a feedback process, a specialized, CFD-modeled dilution cooler is employed along with real-time estimations of the point at which condensation will occur within the dilution cooler to define a level of dilution and diluted gas temperature that results in a gas that can be conveyed to standard gas analyzers that contains no condensed hydrocarbon compounds or condensed moisture.

Method and apparatus maintaining multi-component sample gas constituents in vapor phase during sample extraction and cooling

DOEpatents

Farthing, William Earl; Felix, Larry Gordon; Snyder, Todd Robert

2009-12-15

An apparatus and method for diluting and cooling that is extracted from high temperature and/or high pressure industrial processes. Through a feedback process, a specialized, CFD-modeled dilution cooler is employed along with real-time estimations of the point at which condensation will occur within the dilution cooler to define a level of dilution and diluted gas temperature that results in a gas that can be conveyed to standard gas analyzers that contains no condensed hydrocarbon compounds or condensed moisture.

Use of focused ultrasonication in activity-based profiling of deubiquitinating enzymes in tissue.

PubMed

Nanduri, Bindu; Shack, Leslie A; Rai, Aswathy N; Epperson, William B; Baumgartner, Wes; Schmidt, Ty B; Edelmann, Mariola J

2016-12-15

To develop a reproducible tissue lysis method that retains enzyme function for activity-based protein profiling, we compared four different methods to obtain protein extracts from bovine lung tissue: focused ultrasonication, standard sonication, mortar & pestle method, and homogenization combined with standard sonication. Focused ultrasonication and mortar & pestle methods were sufficiently effective for activity-based profiling of deubiquitinases in tissue, and focused ultrasonication also had the fastest processing time. We used focused-ultrasonicator for subsequent activity-based proteomic analysis of deubiquitinases to test the compatibility of this method in sample preparation for activity-based chemical proteomics. Copyright © 2016 Elsevier Inc. All rights reserved.

Deodorant effects of a sage extract stick: Antibacterial activity and sensory evaluation of axillary deodorancy

PubMed Central

Shahtalebi, Mohammad Ali; Ghanadian, Mustafa; Farzan, Ali; Shiri, Niloufar; Shokri, Dariush; Fatemi, Syed Ali

2013-01-01

Background: Deodorant products prevent the growth and activity of the degrading apocrine gland bacteria living in the armpit. Common antibacterial agents in the market like triclosan and aluminum salts, in spite of their suitable antibacterial effects, increase the risk of Alzheimer's disease, breast and prostate cancers or induce contact dermatitis. Therefore, plant extracts possessing antibacterial effects are of interest. The aim of the present study was to verify the in vitro antimicrobial effects of different sage extracts against two major bacteria responsible for axillary odor, and to evaluate the deodorant effect of a silicon-based stick containing sage extracts in different densities in humans. Materials and Methods: Different fractions of methanolic extract of Salvia officinalis (sage) were evaluated on a culture of armpit skin surface of volunteers through agar microdilution antimicrobial assay. Then, randomized, double-blind placebo-controlled clinical trial with the best antibacterial fraction was conducted on 45 female healthy volunteers. Participants were treated with a single dose in four groups, each containing 15 individuals: Group 1 (200 μg/mL), 2 (400 μg/mL), 3 (600 μg/mL) of dichloromethane sage extract, and placebo (without extract). A standard sensory evaluation method for the evaluation of deodorant efficacy was used before, and two hours, four hours, and eight hours after single application of a deodorant or placebo (ASTM method E 1207-87 Standard Practice for the Sensory Evaluation of Axillary Deodorancy). Results: The data were analyzed with two factors relating to densities and time. In 45 participants with a mean [± standard deviation (SD)] age of 61.5±11.8 years, statistically significant within-group differences were observed before and two, four, and eight hours after deodorant treatment for groups 1, 2, and 3. Groups 1, 2, and 3 had a significantly smaller odor score than placebo after two, four, and eight hours (P < 0.001). In a comparison of different deodorant densities, the interaction effect was not significant between deodorant 200 and 400 μg/mL, but was significant between 200 and 600 and between 400 and 600 μg/mL sage extract sticks (P < 0.001). Before running the sensory evaluation of the deodorant sticks on the subjects, a rabbit skin patch test was used to demonstrate that the formulation had no irritants. Conclusion: A single treatment with a stick deodorant containing dichloromethane sage extract of 200, 400, or 600 μg/mL concentrations was effective in reducing the axillary malodor level compared with the control, in healthy subjects. PMID:24497852

Method development for the analysis of N-nitrosodimethylamine and other N-nitrosamines in drinking water at low nanogram/liter concentrations using solid-phase extraction and gas chromatography with chemical ionization tandem mass spectrometry.

PubMed

Munch, Jean W; Bassett, Margarita V

2006-01-01

N-nitrosodimethylamine (NDMA) is a probable human carcinogen of concern that has been identified as a drinking water contaminant. U.S. Environmental Protection Agency Method 521 has been developed for the analysis of NDMA and 6 additional N-nitrosamines in drinking water at low ng/L concentrations. The method uses solid-phase extraction with coconut charcoal as the sorbent and dichloromethane as the eluent to concentrate 0.50 L water samples to 1 mL. The extracts are analyzed by gas chromatography-chemical ionization tandem mass spectrometry using large-volume injection. Method performance was evaluated in 2 laboratories. Typical analyte recoveries of 87-104% were demonstrated for fortified reagent water samples, and recoveries of 77-106% were demonstrated for fortified drinking water samples. All relative standard deviations on replicate analyses were < 11%.

Rapid and simple method for the determination of emodin in tartary buckwheat (Fagopyrum tataricum) by high-performance liquid chromatography coupled to a diode array detector.

PubMed

Peng, Lian-Xin; Wang, Jing-Bo; Hu, Li-Xue; Zhao, Jiang-Lin; Xiang, Da-Bing; Zou, Liang; Zhao, Gang

2013-01-30

A simple and rapid method for determining emodin, an active factor presented in tartary buckwheat (Fagopyrum tataricum), by high-performance liquid chromatography coupled to a diode array detector (HPLC-DAD) has been developed. Emodin was separated from an extract of buckwheat on a Kromasil-ODS C(18) (250 mm × 4.6 mm × 5 μm) column. The separation is achieved within 15 min on the ODS column. Emodin can be quantified using an external standard method detecting at 436 nm. Good linearity is obtained with a correlation coefficient exceeding 0.9992. The limit of detection and the limit of quantification are 5.7 and 19 μg/L, respectively. This method shows good reproducibility for the quantification of the emodin with a relative standard deviation value of 4.3%. Under optimized extraction conditions, the recovery of emodin was calculated as >90%. The validated method is successfully applied to quantify the emodin in tartary buckwheat and its products.

A new separation and preconcentration method for selenium in some foods using modified silica gel with 2,6-diamino-4-phenil-1,3,5-triazine.

PubMed

Mendil, Durali; Demirci, Zafer; Uluozlu, Ozgur Dogan; Tuzen, Mustafa; Soylak, Mustafa

2017-04-15

A novel and simple solid phase extraction method was improved and recommended for selenium. Silica gel was modified with 2,6-diamino-4-phenil-1,3,5-triazine and characterized by FTIR, SEM and elemental analysis and used adsorbent for column solid phase extraction of selenium ions. The experimental parameters (pH, flow rates, amounts of the modified silica gel, concentration and type of eluent, volume of sample, etc.) on the recoveries of selenium were optimized. Standard reference materials were analyzed for validation of method. The present method was successfully applied to the detection of total selenium in water and microwave digested some food samples with quantitative recoveries (> 95%). The relative standard deviations were<8%. Matrix influences were not observed. The adsorption capacity of modified silica gel was 5.90mgg -1 . The LOD was 0.015μgL -1 . Enrichment factor was obtained as 50 for the introduced method. Copyright © 2016 Elsevier Ltd. All rights reserved.

Technical aspects on production of fluid extract from Brosimum gaudichaudii Trécul roots

PubMed Central

Martins, Frederico Severino; Pascoa, Henrique; de Paula, José Realino; da Conceição, Edemilson Cardoso

2015-01-01

Instruction: Despite the increased use of Brosimum gaudichaudii roots as raw material on medicine to treatment of vitiligo, there are not studies that showing the impact of unit operations on the quality and standardized of the extract of B. gaudichaudii. The quality of the herbal extract is essential to ensure the safety and efficacy of pharmaceutical product. Due the medical and commercial importance, this study aimed to evaluate the impact of the extraction method (ultrasound or percolation) on the quality of herbal extract and optimize the extraction of psoralen and 8-methoxypsoralen (8-MOP) from B. gaudichaudii. Materials and Methods: The extraction recovery was evaluate by high-performance liquid chromatography (C8 reverse phase column and acetonitrile: Water 45:55 and flow rate 0.6 mL/min). The extraction was performed by ultrasound-assisted extraction (UEA) or percolation using a Box-Behnken design. Results: From both chemical markers (psoralen and bergapten), the optimal conditions for the UEA were an extraction time of 25 min, the mean particle size of 100 μm, and an ethanol: Water ratio of 55:45 (v/v). Conclusion: The extraction by percolation revealed that ethanol 55% was more efficient than ethanol 80% to extract psoralen and bergapten. PMID:25709236

A surrogate analyte method to determine D-serine in mouse brain using liquid chromatography-tandem mass spectrometry.

PubMed

Kinoshita, Kohnosuke; Jingu, Shigeji; Yamaguchi, Jun-ichi

2013-01-15

A bioanalytical method for determining endogenous d-serine levels in the mouse brain using a surrogate analyte and liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed. [2,3,3-(2)H]D-serine and [(15)N]D-serine were used as a surrogate analyte and an internal standard, respectively. The surrogate analyte was spiked into brain homogenate to yield calibration standards and quality control (QC) samples. Both endogenous and surrogate analytes were extracted using protein precipitation followed by solid phase extraction. Enantiomeric separation was achieved on a chiral crown ether column with an analysis time of only 6 min without any derivatization. The column eluent was introduced into an electrospray interface of a triple-quadrupole mass spectrometer. The calibration range was 1.00 to 300 nmol/g, and the method showed acceptable accuracy and precision at all QC concentration levels from a validation point of view. In addition, the brain d-serine levels of normal mice determined using this method were the same as those obtained by a standard addition method, which is time-consuming but is often used for the accurate measurement of endogenous substances. Thus, this surrogate analyte method should be applicable to the measurement of d-serine levels as a potential biomarker for monitoring certain effects of drug candidates on the central nervous system. Copyright © 2012 Elsevier Inc. All rights reserved.

Ion-pair vortex assisted liquid-liquid microextraction with back extraction coupled with high performance liquid chromatography-UV for the determination of metformin in plasma.

PubMed

Alshishani, Anas; Makahleh, Ahmad; Yap, Hui Fang; Gubartallah, Elbaleeq Adam; Salhimi, Salizawati Muhamad; Saad, Bahruddin

2016-12-01

A new sample preparation method, ion-pair vortex assisted liquid-liquid microextraction (VALLME-BE), for the determination of a highly polar anti-diabetic drug (metformin) in plasma sample was developed. The VALLME-BE was performed by diluting the plasma in borate buffer and extracted to 150µL 1-octanol containing 0.2M di-(2-ethylhexyl)phosphoric acid as intermediate phase. The drug was next back-extracted into 20µL of 0.075M HCl solution. The effects of pH, ion-pair concentration, type of organic solvent, volume of extraction phases, ionic strength, vortexing and centrifugation times on the extraction efficiency were investigated. The optimum conditions were at pH 9.3, 60s vortexing and 2min centrifugation. The microextract, contained metformin and buformin (internal standard), was directly injected into a HPLC unit using C1 column (250mm×4.6mm×10µm) and detected at 235nm. The method was validated and calibration curve was linear with r 2 >0.99 over the range of 20-2000µgL -1 . The limits of detection and quantitation were 1.4 and 4.1µgL -1 , respectively. The accuracy was within 94.8-108% of the nominal concentration. The relative standard deviation for inter- and intra-day precision was less than 10.8%. The method was conveniently applied for the determination of metformin in plasma samples. Copyright © 2016 Elsevier B.V. All rights reserved.

METHOD FOR THE DETERMINATION OF PERCHLORATE ANION IN PLANT AND SOLID MATRICES BY ION CHROMATOGRAPHY

EPA Science Inventory

A standardized method for the analysis of perchlorate in plants was developed, based on dry weight, and applied to the analysis of plant organs, foodstuffs, and plant products. The procedure greatly reduced the ionic interferences in water extracts of plant materials. Ion chro...

Single Laboratory Validated Method for Determination of Microcystins and Nodularin in Ambient Freshwaters by Solid Phase Extraction and Liquid Chromatography/ Tandem Mass Spectrometry (LC/MS/MS)

EPA Pesticide Factsheets

This document is a standardized, single laboratory validated liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for the detection of cyanotoxins—microsystins and nodularin (combined intracellular and extracellular)—in ambient freshwaters.

Analysis of phytochemical profile of Terminalia arjuna bark extract with antioxidative and antimicrobial properties.

PubMed

Mandal, Shreya; Patra, Arpita; Samanta, Animesh; Roy, Suchismita; Mandal, Arpita; Mahapatra, Tapasi Das; Pradhan, Shrabani; Das, Koushik; Nandi, Dilip Kumar

2013-12-01

To investigate phytochemical screening, antimicrobial activity and qualitative thin layer chromatographic separation of flavonoid components, antioxidant activity and total flavonoid compound of Terminalia arjuna. For phytochemical screening, some common and available standard tests were done. Antimicrobial bioassay was done through agar well diffusion method. Detection of antioxidant activity and flavonoid compounds were done through thin layer chromatography. Total antioxidant activity was measured by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) in colorimetric method. Aluminum chloride colorimetric method was used for total flavonoid determination. Phytochemical screening showed the active compounds presence in high concentration, such as phytosterol, lactones, flavonoids, phenolic compounds and tannins and glycosides. The antimicrobial activity of extract showed that greater inhibition zone against Gram negative bacteria than Gram positive bacteria. This methanolic extract showed a promising antioxidant activity, as absorption of DPPH redicles decreased in DPPH free radical scavenging assay. Flavonoids components having antioxidant property present in the methanol extract at a level of 199.00 mg quercetin equivalent/g of dried methanol extract in colorimetric method. The Terminalia arjuna bark extract revealed the presence of bio-active constituents which are known to exhibit medicinal as well as physiological activities. Copyright © 2013 Asian Pacific Tropical Biomedical Magazine. Published by Elsevier B.V. All rights reserved.

Comparison of supercritical fluid extraction and Soxhlet extraction for the determination of PCBs in seaweed samples.

PubMed

Punín Crespo, M O; Lage Yusty, M A

2005-06-01

The efficiency of supercritical fluid extraction for the determination of 12 polychlorinated biphenyls from algae samples is compared to Soxhlet extraction. Analytical detection limits for the individual congeners ranged from 0.62 microgl(-1) to 19 microgl(-1). Recovery was tested for both methods using standard addition procedure. At maximum spike level of concentration, the mean recoveries were not significantly different (P>0.05) of all PCBs studied, with the exception of PCBs 28, 52, 77 and 169. Method precision for Soxhlet extraction (< or =3.9%) was slightly better than for SFE (< or =9.2%). Although both methods yield comparable results, SFE offers the advantage of detecting all PCBs studied at lower concentrations, reducing extraction time, and reducing the amount of solvents needed. The optimized methods were applied to the analysis of three real seaweed samples, except for PCB101 the concentrations of all PCBs were low or below the detection limits. The levels of PCB101 found in sample 1 were 6.6+/-0.54 ng g(-1) d.w., in sample 2 the levels were 8.2+/-0.86 ng g(-1) d.w. and in sample 3 they were 7.7+/-0.08 ng g(-1) d.w.

Estimation of total phenolic content, in-vitro antioxidant and anti-inflammatory activity of flowers of Moringa oleifera

PubMed Central

Alhakmani, Fatma; Kumar, Sokindra; Khan, Shah Alam

2013-01-01

Objective To evaluate and compare the antioxidant potential and anti-inflammatory activity of ethanolic extract of flowers of Moringa oleifera (M. oleifera) grown in Oman. Methods Flowers of M. oleifera were collected in the month of December 2012 and identified by a botanist. Alcoholic extract of the dry pulverized flowers of M. oleifera were obtained by cold maceration method. The ethanolic flower extract was subjected to preliminary phytochemical screening as the reported methods. Folin-Ciocalteu reagent was used to estimate total phenolic content. DPPH was used to determine in-vitro antioxidant activity and anti-inflammatory activity of flowers was investigated by protein denaturation method. Results Phytochemical analysis of extract showed presence of major classes of phytochemicals such as tannins, alkaloids, flavonoids, cardiac glycosides etc. M. oleifera flowers were found to contain 19.31 mg/g of gallic acid equivalent of total phenolics in dry extract but exhibited moderate antioxidant activity. The anti-inflammatory activity of plant extract was significant and comparable with the standard drug diclofenac sodium. Conclusions The results of our study suggest that flowers of M. oleifera possess potent anti-inflammatory activity and are also a good source of natural antioxidants. Further study is needed to identify the chemical compounds responsible for their anti-inflammatory activity. PMID:23905019

Evaluation of traditional Chinese medicinal plants for anti-MRSA activity with reference to the treatment record of infectious diseases.

PubMed

Zuo, Guo-Ying; Zhang, Xin-Juan; Yang, Cui-Xian; Han, Jun; Wang, Gen-Chun; Bian, Zhong-Qi

2012-03-09

The in vitro antimicrobial activities of 30 Chinese medicinal plants were evaluated with reference to the treatment record of infectious diseases in the Traditional Chinese Medicine (TCM) literature. The plant materials were extracted with 80% ethanol and the extracts were primarily screened against conventional clinical pathogens like Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans by the agar diffusion method. Their inhibition zone diameters (IZDs, mm, 50 mg/mL) ranged from 2,048 by the standard broth microdilution method. The seven extracts from M. yunnanensis, S. sinensis, G. morella, E. daneillii, M. squamulata, S. arborescens and B. hancei were determined as the most active extracts, with MICs of 8-64 μg/mL. The results were in good agreement with their traditional applications in skin and other infections.

DNA extraction for streamlined metagenomics of diverse environmental samples.

PubMed

Marotz, Clarisse; Amir, Amnon; Humphrey, Greg; Gaffney, James; Gogul, Grant; Knight, Rob

2017-06-01

A major bottleneck for metagenomic sequencing is rapid and efficient DNA extraction. Here, we compare the extraction efficiencies of three magnetic bead-based platforms (KingFisher, epMotion, and Tecan) to a standardized column-based extraction platform across a variety of sample types, including feces, oral, skin, soil, and water. Replicate sample plates were extracted and prepared for 16S rRNA gene amplicon sequencing in parallel to assess extraction bias and DNA quality. The data demonstrate that any effect of extraction method on sequencing results was small compared with the variability across samples; however, the KingFisher platform produced the largest number of high-quality reads in the shortest amount of time. Based on these results, we have identified an extraction pipeline that dramatically reduces sample processing time without sacrificing bacterial taxonomic or abundance information.

Stable Isolation of Phycocyanin from Spirulina platensis Associated with High-Pressure Extraction Process

PubMed Central

Seo, Yong Chang; Choi, Woo Seok; Park, Jong Ho; Park, Jin Oh; Jung, Kyung-Hwan; Lee, Hyeon Yong

2013-01-01

A method for stably purifying a functional dye, phycocyanin from Spirulina platensis was developed by a hexane extraction process combined with high pressure. This was necessary because this dye is known to be very unstable during normal extraction processes. The purification yield of this method was estimated as 10.2%, whose value is 3%–5% higher than is the case from another conventional separation method using phosphate buffer. The isolated phycocyanin from this process also showed the highest purity of 0.909 based on absorbance of 2.104 at 280 nm and 1.912 at 620 nm. Two subunits of phycocyanin namely α-phycocyanin (18.4 kDa) and β-phycocyanin (21.3 kDa) were found to remain from the original mixtures after being extracted, based on SDS-PAGE analysis, clearly demonstrating that this process can stably extract phycocyanin and is not affected by extraction solvent, temperature, etc. The stability of the extracted phycocyanin was also confirmed by comparing its DPPH (α,α-diphenyl-β-picrylhydrazyl) scavenging activity, showing 83% removal of oxygen free radicals. This activity was about 15% higher than that of commercially available standard phycocyanin, which implies that the combined extraction method can yield relatively intact chromoprotein through absence of degradation. The results were achieved because the low temperature and high pressure extraction effectively disrupted the cell membrane of Spirulina platensis and degraded less the polypeptide subunits of phycocyanin (which is a temperature/pH-sensitive chromoprotein) as well as increasing the extraction yield. PMID:23325046

Diethylstilbestrol in fish tissue determined through subcritical fluid extraction and with GC-MS

NASA Astrophysics Data System (ADS)

Qiao, Qinghui; Shi, Nianrong; Feng, Xiaomei; Lu, Jie; Han, Yuqian; Xue, Changhu

2016-06-01

As the key point in sex hormone analysis, sample pre-treatment technology has attracted scientists' attention all over the world, and the development trend of sample preparation forwarded to faster and more efficient technologies. Taking economic and environmental concerns into account, subcritical fluid extraction as a faster and more efficient method has stood out as a sample pre-treatment technology. This new extraction technology can overcome the shortcomings of supercritical fluid and achieve higher extraction efficiency at relatively low pressures and temperatures. In this experiment, a simple, sensitive and efficient method has been developed for the determination of diethylstilbestrol (DES) in fish tissue using subcritical 1,1,1,2-tetrafluoroethane (R134a) extraction in combination with gas chromatography-mass spectrometry (GC-MS). After extraction, freezing-lipid filtration was utilized to remove fatty co-extract. Further purification steps were performed with C18 and NH2 solid phase extraction (SPE). Finally, the analyte was derived by heptafluorobutyric anhydride (HFBA), followed by GC-MS analysis. Response surface methodology (RSM) was employed to optimizing the extraction condition, and the optimized was as follows: extraction pressure, 4.3 MPa; extraction temperature, 26°C; amount of co-solvent volume, 4.7 mL. Under this condition, at a spiked level of 1, 5, 10 μg kg-1, the mean recovery of DES was more than 90% with relative standard deviations (RSDs) less than 10%. Finally, the developed method has been successfully used to analyzing the real samples.

Joint classification and contour extraction of large 3D point clouds

NASA Astrophysics Data System (ADS)

Hackel, Timo; Wegner, Jan D.; Schindler, Konrad

2017-08-01

We present an effective and efficient method for point-wise semantic classification and extraction of object contours of large-scale 3D point clouds. What makes point cloud interpretation challenging is the sheer size of several millions of points per scan and the non-grid, sparse, and uneven distribution of points. Standard image processing tools like texture filters, for example, cannot handle such data efficiently, which calls for dedicated point cloud labeling methods. It turns out that one of the major drivers for efficient computation and handling of strong variations in point density, is a careful formulation of per-point neighborhoods at multiple scales. This allows, both, to define an expressive feature set and to extract topologically meaningful object contours. Semantic classification and contour extraction are interlaced problems. Point-wise semantic classification enables extracting a meaningful candidate set of contour points while contours help generating a rich feature representation that benefits point-wise classification. These methods are tailored to have fast run time and small memory footprint for processing large-scale, unstructured, and inhomogeneous point clouds, while still achieving high classification accuracy. We evaluate our methods on the semantic3d.net benchmark for terrestrial laser scans with >109 points.

Comparison of two thin-film microextractions for the analysis of estrogens in aqueous tea extract and environmental water samples by high performance liquid chromatography-ultraviolet detection.

PubMed

Cai, Pei-Shan; Li, Dan; Chen, Jing; Xiong, Chao-Mei; Ruan, Jin-Lan

2015-04-15

Two thin-film microextractions (TFME), octadecylsilane (ODS)-polyacrylonitrile (PAN)-TFME and polar enhanced phase (PEP)-PAN-TFME have been proposed for the analysis of bisphenol-A, diethylstilbestrol and 17β-estradiol in aqueous tea extract and environmental water samples followed by high performance liquid chromatography-ultraviolet detection. Both thin-films were prepared by spraying. The influencing factors including pH, extraction time, desorption solvent, desorption volume, desorption time, ion strength and reusability were investigated. Under the optimal conditions, the two TFME methods are similar in terms of the analytical performance evaluated by standard addition method. The limits of detection for three estrogens in environmental water and aqueous tea extract matrix ranged from 1.3 to 1.6 and 2.8 to 7.1 ng mL(-1) by the two TFME methods, respectively. Both approaches were applied for the analysis of analytes in real aqueous tea extract and environmental water samples, presenting satisfactory recoveries ranged from 87.3% to 109.4% for the spiked samples. Copyright © 2014 Elsevier Ltd. All rights reserved.

GPU surface extraction using the closest point embedding

NASA Astrophysics Data System (ADS)

Kim, Mark; Hansen, Charles

2015-01-01

Isosurface extraction is a fundamental technique used for both surface reconstruction and mesh generation. One method to extract well-formed isosurfaces is a particle system; unfortunately, particle systems can be slow. In this paper, we introduce an enhanced parallel particle system that uses the closest point embedding as the surface representation to speedup the particle system for isosurface extraction. The closest point embedding is used in the Closest Point Method (CPM), a technique that uses a standard three dimensional numerical PDE solver on two dimensional embedded surfaces. To fully take advantage of the closest point embedding, it is coupled with a Barnes-Hut tree code on the GPU. This new technique produces well-formed, conformal unstructured triangular and tetrahedral meshes from labeled multi-material volume datasets. Further, this new parallel implementation of the particle system is faster than any known methods for conformal multi-material mesh extraction. The resulting speed-ups gained in this implementation can reduce the time from labeled data to mesh from hours to minutes and benefits users, such as bioengineers, who employ triangular and tetrahedral meshes

A simple method for determination of carmine in food samples based on cloud point extraction and spectrophotometric detection.

PubMed

Heydari, Rouhollah; Hosseini, Mohammad; Zarabi, Sanaz

2015-01-01

In this paper, a simple and cost effective method was developed for extraction and pre-concentration of carmine in food samples by using cloud point extraction (CPE) prior to its spectrophotometric determination. Carmine was extracted from aqueous solution using Triton X-100 as extracting solvent. The effects of main parameters such as solution pH, surfactant and salt concentrations, incubation time and temperature were investigated and optimized. Calibration graph was linear in the range of 0.04-5.0 μg mL(-1) of carmine in the initial solution with regression coefficient of 0.9995. The limit of detection (LOD) and limit of quantification were 0.012 and 0.04 μg mL(-1), respectively. Relative standard deviation (RSD) at low concentration level (0.05 μg mL(-1)) of carmine was 4.8% (n=7). Recovery values in different concentration levels were in the range of 93.7-105.8%. The obtained results demonstrate the proposed method can be applied satisfactory to determine the carmine in food samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Evaluation of Drying Process on the Composition of Black Pepper Ethanolic Extract by High Performance Liquid Chromatography With Diode Array Detector

PubMed Central

Namjoyan, Foroogh; Hejazi, Hoda; Ramezani, Zahra

2012-01-01

Background Black pepper (Piper nigrum) is one of the well-known spices extensively used worldwide especially in India, and Southeast Asia. The presence of alkaloids in the pepper, namely, piperine and its three stereoisomers, isopiperine, chavicine and isochavicine are well noticed. Objectives The current study evaluated the effect of lyophilization and oven drying on the stability and decomposition of constituents of black pepper ethanolic extract. Materials and Methods In the current study ethanolic extract of black pepper obtained by maceration method was dried using two methods. The effect of freeze and oven drying on the chemical composition of the extract especially piperine and its three isomers were evaluated by HPLC analysis of the ethanolic extract before and after drying processes using diode array detector. The UV Vis spectra of the peaks at piperine retention time before and after each drying methods indicated maximum absorbance at 341.2 nm corresponding to standard piperine. Results The results indicated a decrease in intensity of the chromatogram peaks at approximately all retention times after freeze drying, indicating a few percent loss of piperine and its isomers upon lyophilization. Two impurity peaks were completely removed from the extract. Conclusions In oven dried samples two of the piperine stereoisomers were completely removed from the extract and the intensity of piperine peak was increased. PMID:24624176

Fast and accurate determination of arsenobetaine in fish tissues using accelerated solvent extraction and HPLC-ICP-MS determination.

PubMed

Wahlen, Raimund

2004-04-01

A high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) method has been developed for the fast and accurate analysis of arsenobetaine (AsB) in fish samples extracted by accelerated solvent extraction. The combined extraction and analysis approach is validated using certified reference materials for AsB in fish and during a European intercomparison exercise with a blind sample. Up to six species of arsenic (As) can be separated and quantitated in the extracts within a 10-min isocratic elution. The method is optimized so as to minimize time-consuming sample preparation steps and allow for automated extraction and analysis of large sample batches. A comparison of standard addition and external calibration show no significant difference in the results obtained, which indicates that the LC-ICP-MS method is not influenced by severe matrix effects. The extraction procedure can process up to 24 samples in an automated manner, yet the robustness of the developed HPLC-ICP-MS approach is highlighted by the capability to run more than 50 injections per sequence, which equates to a total run-time of more than 12 h. The method can therefore be used to rapidly and accurately assess the proportion of nontoxic AsB in fish samples with high total As content during toxicological screening studies.

Semiautomatic sequential extraction of polycyclic aromatic hydrocarbons and elemental bio-accessible fraction by accelerated solvent extraction on a single particulate matter sample.

PubMed

Astolfi, Maria Luisa; Di Filippo, Patrizia; Gentili, Alessandra; Canepari, Silvia

2017-11-01

We describe the optimization and validation of a sequential extractive method for the determination of the polycyclic aromatic hydrocarbons (PAHs) and elements (Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Se, V and Zn) that are chemically fractionated into bio-accessible and mineralized residual fractions on a single particulate matter filter. The extraction is performed by automatic accelerated solvent extraction (ASE); samples are sequentially treated with dichloromethane/acetone (4:1) for PAHs extraction and acetate buffer (0.01M; pH 4.5) for elements extraction (bio-accessible fraction). The remaining solid sample is then collected and subjected to acid digestion with HNO 3 :H 2 O 2 (2:1) to determine the mineralized residual element fraction. We also describe a homemade ASE cell that reduces the blank values for most elements; in this cell, the steel frit was replaced by a Teflon pierced disk and a Teflon cylinder was used as the filler. The performance of the proposed method was evaluated in terms of recovery from standard reference material (SRM 1648 and SRM 1649a) and repeatability. The equivalence between the new ASE method and conventional methods was verified for PAHs and for bio-accessible and mineralized residual fractions of elements on PM 10 twin filters. Copyright © 2017 Elsevier B.V. All rights reserved.

Wide-Scope Screening Method for Multiclass Veterinary Drug Residues in Fish, Shrimp, and Eel Using Liquid Chromatography-Quadrupole High-Resolution Mass Spectrometry.

PubMed

Turnipseed, Sherri B; Storey, Joseph M; Lohne, Jack J; Andersen, Wendy C; Burger, Robert; Johnson, Aaron S; Madson, Mark R

2017-08-30

A screening method for veterinary drug residues in fish, shrimp, and eel using LC with a high-resolution MS instrument has been developed and validated. The method was optimized for over 70 test compounds representing a variety of veterinary drug classes. Tissues were extracted by vortex mixing with acetonitrile acidified with 2% acetic acid and 0.2% p-toluenesulfonic acid. A centrifuged portion of the extract was passed through a novel solid phase extraction cartridge designed to remove interfering matrix components from tissue extracts. The eluent was then evaporated and reconstituted for analysis. Data were collected with a quadrupole-Orbitrap high-resolution mass spectrometer using both nontargeted and targeted acquisition methods. Residues were detected on the basis of the exact mass of the precursor and a product ion along with isotope pattern and retention time matching. Semiquantitative data analysis compared MS 1 signal to a one-point extracted matrix standard at a target testing level. The test compounds were detected and identified in salmon, tilapia, catfish, shrimp, and eel extracts fortified at the target testing levels. Fish dosed with selected analytes and aquaculture samples previously found to contain residues were also analyzed. The screening method can be expanded to monitor for an additional >260 veterinary drugs on the basis of exact mass measurements and retention times.

Tendency for interlaboratory precision in the GMO analysis method based on real-time PCR.

PubMed

Kodama, Takashi; Kurosawa, Yasunori; Kitta, Kazumi; Naito, Shigehiro

2010-01-01

The Horwitz curve estimates interlaboratory precision as a function only of concentration, and is frequently used as a method performance criterion in food analysis with chemical methods. The quantitative biochemical methods based on real-time PCR require an analogous criterion to progressively promote method validation. We analyzed the tendency of precision using a simplex real-time PCR technique in 53 collaborative studies of seven genetically modified (GM) crops. Reproducibility standard deviation (SR) and repeatability standard deviation (Sr) of the genetically modified organism (GMO) amount (%) was more or less independent of GM crops (i.e., maize, soybean, cotton, oilseed rape, potato, sugar beet, and rice) and evaluation procedure steps. Some studies evaluated whole steps consisting of DNA extraction and PCR quantitation, whereas others focused only on the PCR quantitation step by using DNA extraction solutions. Therefore, SR and Sr for GMO amount (%) are functions only of concentration similar to the Horwitz curve. We proposed S(R) = 0.1971C 0.8685 and S(r) = 0.1478C 0.8424, where C is the GMO amount (%). We also proposed a method performance index in GMO quantitative methods that is analogous to the Horwitz Ratio.

Optimization of cloud point extraction and solid phase extraction methods for speciation of arsenic in natural water using multivariate technique.

PubMed

Baig, Jameel A; Kazi, Tasneem G; Shah, Abdul Q; Arain, Mohammad B; Afridi, Hassan I; Kandhro, Ghulam A; Khan, Sumaira

2009-09-28

The simple and rapid pre-concentration techniques viz. cloud point extraction (CPE) and solid phase extraction (SPE) were applied for the determination of As(3+) and total inorganic arsenic (iAs) in surface and ground water samples. The As(3+) was formed complex with ammonium pyrrolidinedithiocarbamate (APDC) and extracted by surfactant-rich phases in the non-ionic surfactant Triton X-114, after centrifugation the surfactant-rich phase was diluted with 0.1 mol L(-1) HNO(3) in methanol. While total iAs in water samples was adsorbed on titanium dioxide (TiO(2)); after centrifugation, the solid phase was prepared to be slurry for determination. The extracted As species were determined by electrothermal atomic absorption spectrometry. The multivariate strategy was applied to estimate the optimum values of experimental factors for the recovery of As(3+) and total iAs by CPE and SPE. The standard addition method was used to validate the optimized methods. The obtained result showed sufficient recoveries for As(3+) and iAs (>98.0%). The concentration factor in both cases was found to be 40.

Human beta-glucuronidase. Measurement of its activity in gallbladder bile devoid of intrinsic interference.

PubMed

Ho, Y C; Ho, K J

1988-04-01

Our purpose is to develop a standard method for preparing the bile for beta-glucuronidase determination by removal of bile acids and conjugated bilirubin which interfere with its activity. The bile acids and conjugated bilirubin in their purified solutions and in the diluted gallbladder biles could be extracted completely with cholestyramine in powder form or tetrahexylammonium chloride (THAC) in chloroform or ethyl acetate. The enzyme was, however, partially precipitated with cholestyramine and denatured by chloroform but not by ethyl acetate. A standard procedure, therefore, includes extraction of the diluted gallbladder bile with THAC in ethyl acetate, followed by determination of the maximal velocity (Vmax) of the enzyme by a kinetic method employing phenolphthalein glucuronide as the substrate. The average Vmax of beta-glucuronidase in the 20 normal gallbladder biles was 165 +/- 86 nmol/min/ml (mean +/- SD), a 23.5-fold increase over the activity before extraction. The measured activity represented the true activity of the enzyme in the bile for recovery of activity of the enzyme added to the bile was practically complete.

Evaluation of FTA ® paper for storage of oral meta-genomic DNA.

PubMed

Foitzik, Magdalena; Stumpp, Sascha N; Grischke, Jasmin; Eberhard, Jörg; Stiesch, Meike

2014-10-01

The purpose of the present study was to evaluate the short-term storage of meta-genomic DNA from native oral biofilms on FTA(®) paper. Thirteen volunteers of both sexes received an acrylic splint for intraoral biofilm formation over a period of 48 hours. The biofilms were collected, resuspended in phosphate-buffered saline, and either stored on FTA(®) paper or directly processed by standard laboratory DNA extraction. The nucleic acid extraction efficiencies were evaluated by 16S rDNA targeted SSCP fingerprinting. The acquired banding pattern of FTA-derived meta-genomic DNA was compared to a standard DNA preparation protocol. Sensitivity and positive predictive values were calculated. The volunteers showed inter-individual differences in their bacterial species composition. A total of 200 bands were found for both methods and 85% of the banding patterns were equal, representing a sensitivity of 0.941 and a false-negative predictive value of 0.059. Meta-genomic DNA sampling, extraction, and adhesion using FTA(®) paper is a reliable method for storage of microbial DNA for a short period of time.

Determination of rhenium content in molybdenite by ICP-MS after separation of the major matrix by solvent extraction with N-benzoyl-N-phenylhydroxalamine.

PubMed

Li, Jie; Zhong, Li-feng; Tu, Xiang-lin; Liang, Xi-rong; Xu, Ji-feng

2010-05-15

A simple and rapid analytical method for determining the concentration of rhenium in molybdenite for Re-Os dating was developed. The method used isotope dilution-inductively coupled plasma-mass spectrometry (ID-ICP-MS) after the removal of major matrix elements (e.g., Mo, Fe, and W) from Re by solvent extraction with N-benzoyl-N-phenylhydroxylamine (BPHA) in chloroform solution. The effect on extraction efficiency of parameters such as pH (HCl concentration), BPHA concentration, and extraction time were also assessed. Under the optimal experimental conditions, the validity of the separation method was accessed by measuring (187)Re/(185)Re values for a molybdenite reference material (JDC). The obtained values were in good agreement with previously measured values of the Re standard. The proposed method was applied to replicate Re-Os dating of JDC and seven samples of molybdenite from the Yuanzhuding large Cu-Mo porphyry deposit. The results demonstrate good precision and accuracy for the proposed method. The advantages of the method (i.e., simplicity, efficiency, short analysis time, and low cost) make it suitable for routine analysis.

Critical Evaluation of Soil Pore Water Extraction Methods on a Natural Soil

NASA Astrophysics Data System (ADS)

Orlowski, Natalie; Pratt, Dyan; Breuer, Lutz; McDonnell, Jeffrey

2017-04-01

Soil pore water extraction is an important component in ecohydrological studies for the measurement of δ2H and δ18O. The effect of pore water extraction technique on resultant isotopic signature is poorly understood. Here we present results of an intercomparison of commonly applied lab-based soil water extraction techniques on a natural soil: high pressure mechanical squeezing, centrifugation, direct vapor equilibration, microwave extraction, and two types of cryogenic extraction systems. We applied these extraction methods to a natural summer-dry (gravimetric water contents ranging from 8% to 15%) glacio-lacustrine, moderately fine textured clayey soil; excavated in 10 cm sampling increments to a depth of 1 meter. Isotope results were analyzed via OA-ICOS and compared for each extraction technique that produced liquid water. From our previous intercomparison study among the same extraction techniques but with standard soils, we discovered that extraction methods are not comparable. We therefore tested the null hypothesis that all extraction techniques would be able to replicate the natural evaporation front in a comparable manner occurring in a summer-dry soil. Our results showed that the extraction technique utilized had a significant effect on the soil water isotopic composition. High pressure mechanical squeezing and vapor equilibration techniques produced similar results with similarly sloped evaporation lines. Due to the nature of soil properties and dryness, centrifugation was unsuccessful in obtaining pore water for isotopic analysis. Cryogenic extraction on both tested techniques produced similar results to each other on a similar sloping evaporation line, but dissimilar with depth.

A Rapid Segmentation-Insensitive "Digital Biopsy" Method for Radiomic Feature Extraction: Method and Pilot Study Using CT Images of Non-Small Cell Lung Cancer.

PubMed

Echegaray, Sebastian; Nair, Viswam; Kadoch, Michael; Leung, Ann; Rubin, Daniel; Gevaert, Olivier; Napel, Sandy

2016-12-01

Quantitative imaging approaches compute features within images' regions of interest. Segmentation is rarely completely automatic, requiring time-consuming editing by experts. We propose a new paradigm, called "digital biopsy," that allows for the collection of intensity- and texture-based features from these regions at least 1 order of magnitude faster than the current manual or semiautomated methods. A radiologist reviewed automated segmentations of lung nodules from 100 preoperative volume computed tomography scans of patients with non-small cell lung cancer, and manually adjusted the nodule boundaries in each section, to be used as a reference standard, requiring up to 45 minutes per nodule. We also asked a different expert to generate a digital biopsy for each patient using a paintbrush tool to paint a contiguous region of each tumor over multiple cross-sections, a procedure that required an average of <3 minutes per nodule. We simulated additional digital biopsies using morphological procedures. Finally, we compared the features extracted from these digital biopsies with our reference standard using intraclass correlation coefficient (ICC) to characterize robustness. Comparing the reference standard segmentations to our digital biopsies, we found that 84/94 features had an ICC >0.7; comparing erosions and dilations, using a sphere of 1.5-mm radius, of our digital biopsies to the reference standard segmentations resulted in 41/94 and 53/94 features, respectively, with ICCs >0.7. We conclude that many intensity- and texture-based features remain consistent between the reference standard and our method while substantially reducing the amount of operator time required.

Polypyrrole-magnetite dispersive micro-solid-phase extraction combined with ultraviolet-visible spectrophotometry for the determination of rhodamine 6G and crystal violet in textile wastewater.

PubMed

Kamaruddin, Amirah Farhan; Sanagi, Mohd Marsin; Wan Ibrahim, Wan Aini; Md Shukri, Dyia S; Abdul Keyon, Aemi S

2017-11-01

Polypyrrole-magnetite dispersive micro-solid-phase extraction method combined with ultraviolet-visible spectrophotometry was developed for the determination of selected cationic dyes in textile wastewater. Polypyrrole-magnetite was used as adsorbent due to its thermal stability, magnetic properties, and ability to adsorb Rhodamine 6G and crystal violet. Dispersive micro-solid-phase extraction parameters were optimized, including sample pH, adsorbent amount, extraction time, and desorption solvent. The optimum polypyrrole-magnetite dispersive micro-solid phase-extraction conditions were sample pH 8, 60 mg polypyrrole-magnetite adsorbent, 5 min of extraction time, and acetonitrile as the desorption solvent. Under the optimized conditions, the polypyrrole-magnetite dispersive micro-solid-phase extraction with ultraviolet-visible method showed good linearity in the range of 0.05-7 mg/L (R 2  > 0.9980). The method also showed a good limit of detection for the dyes (0.05 mg/L) and good analyte recoveries (97.4-111.3%) with relative standard deviations < 10%. The method was successfully applied to the analysis of dyes in textile wastewater samples where the concentration found was 1.03 mg (RSD ±7.9%) and 1.13 mg/L (RSD ± 4.6%) for Rhodamine 6G and crystal violet, respectively. It can be concluded that this method can be adopted for the rapid extraction and determination of dyes at trace concentration levels. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A new idea for visualization of lesions distribution in mammogram based on CPD registration method.

PubMed

Pan, Xiaoguang; Qi, Buer; Yu, Hongfei; Wei, Haiping; Kang, Yan

2017-07-20

Mammography is currently the most effective technique for breast cancer. Lesions distribution can provide support for clinical diagnosis and epidemiological studies. We presented a new idea to help radiologists study breast lesions distribution conveniently. We also developed an automatic tool based on this idea which could show visualization of lesions distribution in a standard mammogram. Firstly, establishing a lesion database to study; then, extracting breast contours and match different women's mammograms to a standard mammogram; finally, showing the lesion distribution in the standard mammogram, and providing the distribution statistics. The crucial process of developing this tool was matching different women's mammograms correctly. We used a hybrid breast contour extraction method combined with coherent point drift method to match different women's mammograms. We tested our automatic tool by four mass datasets of 641 images. The distribution results shown by the tool were consistent with the results counted according to their reports and mammograms by manual. We also discussed the registration error that was less than 3.3 mm in average distance. The new idea is effective and the automatic tool can provide lesions distribution results which are consistent with radiologists simply and conveniently.

Determination of cyflumetofen residue in water, soil, and fruits by modified quick, easy, cheap, effective, rugged, and safe method coupled to gas chromatography/tandem mass spectrometry.

PubMed

Li, Minmin; Liu, Xingang; Dong, Fengshou; Xu, Jun; Qin, Dongmei; Zheng, Yongquan

2012-10-01

A new, highly sensitive, and selective method was developed for the determination of the cyflumetofen residue in water, soil, and fruits by using gas chromatography quadruple mass spectrometry. The target compound was extracted using acetonitrile and then cleaned up using dispersive solid-phase extraction with primary and secondary amine and graphitized carbon black, and optionally by a freezing-out cleanup step. The matrix-matched standards gave satisfactory recoveries and relative standard deviation values in different matrices at three fortified levels (0.05, 0.5, and 1.0 mg kg(-1) ). The overall average recoveries for this method in water, soil, and all fruits matrix at three fortified levels ranged from 76.3 to 101.5% with relative standard deviations in the range of 1.2-11.8% (n = 5). The calculated limits of detection and quantification were typically below 0.005 and 0.015 μg kg(-1), which were much lower than the maximum residue levels established by Japanese Positive List. This study provides a theoretical basis for China to draw up maximum residue level and analytical method for cyflumetofen acaricide in different fruits. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

One-Step Extraction and Hydrolysis of Flavonoid Glycosides in Rape Bee Pollen Based on Soxhlet-Assisted Matrix Solid Phase Dispersion.

PubMed

Tu, Xijuan; Ma, Shuangqin; Gao, Zhaosheng; Wang, Jing; Huang, Shaokang; Chen, Wenbin

2017-11-01

Flavonoids are frequently found as glycosylated derivatives in plant materials. To determine contents of flavonoid aglycones in these matrices, procedures for the extraction and hydrolysis of flavonoid glycosides are required. The current sample preparation method is both labour and time consuming. Develop a modified matrix solid phase dispersion (MSPD) procedure as an alternative methodology for the one-step extraction and hydrolysis of flavonoid glycosides. HPLC-DAD was applied for demonstrating the one-step extraction and hydrolysis of flavonoids in rape bee pollen. The obtained contents of flavonoid aglycones (quercetin, kaempferol, isorhamnetin) were used for the optimisation and validation of the method. The extraction and hydrolysis were accomplished in one step. The procedure completes in 2 h with silica gel as dispersant, a 1:2 ratio of sample to dispersant, and 60% aqueous ethanol with 0.3 M hydrochloric acid as the extraction solution. The relative standard deviations (RSDs) of repeatability were less than 5%, and the recoveries at two fortified levels were between 88.3 and 104.8%. The proposed methodology is simple and highly efficient, with good repeatability and recovery. Compared with currently available methods, the present work has advantages of using less time and labour, higher extraction efficiency, and less consumption of the acid catalyst. This method may have applications for the one-step extraction and hydrolysis of bioactive compounds from plant materials. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

[Simultaneous determination of 15 industrial synthetic dyes in condiment by solid phase extraction-high performance liquid chromatography].

PubMed

Liu, Min; Li, Xiaolin; Bie, Wei; Wang, Minglin; Feng, Qian

2011-02-01

A new method was established for the determination of 15 industrial synthetic dyes in condiment by solid phase extraction-high performance liquid chromatography (SPE-HPLC). The samples were extracted by methanol-water (1:1, v/v) and purified by a solid phase extraction column. Then, the chromatographic separation was achieved on a Luna C18 column by linear gradient elution. The mobile phase was 10 mmol/L ammonium acetate-acetonitrile (containing 1% acetic acid). The results showed that the 15 industrial synthetic dyes can be separated efficiently. The recoveries of the 15 industrial synthetic dyes spiked in condiment were between 84.6% and 114.2% with the relative standard deviations of 0.9% - 10.3%. The limits of detection of this method was 0.05 - 0.18 mg/kg for the 15 industrial synthetic dyes. The method is simple, sensitive, accurate, repeatable and can be used for simultaneous determination of the 15 illegally added industrial synthetic dyes.

Fast methodology of analysing major steviol glycosides from Stevia rebaudiana leaves.

PubMed

Lorenzo, Cándida; Serrano-Díaz, Jéssica; Plaza, Miguel; Quintanilla, Carmen; Alonso, Gonzalo L

2014-08-15

The aim of this work is to propose an HPLC method for analysing major steviol glycosides as well as to optimise the extraction and clarification conditions for obtaining these compounds. Toward this aim, standards of stevioside and rebaudioside A with purities ⩾99.0%, commercial samples from different companies and Stevia rebaudiana Bertoni leaves from Paraguay supplied by Insobol, S.L., were used. The analytical method proposed is adequate in terms of selectivity, sensitivity and accuracy. Optimum extraction conditions and adequate clarification conditions have been set. Moreover, this methodology is safe and eco-friendly, as we use only water for extraction and do not use solid-phase extraction, which requires solvents that are banned in the food industry to condition the cartridge and elute the steviol glycosides. In addition, this methodology consumes little time as leaves are not ground and the filtration is faster, and the peak resolution is better as we used an HPLC method with gradient elution. Copyright © 2014 Elsevier Ltd. All rights reserved.

Automated solid-phase extraction and liquid chromatography for assay of cyclosporine in whole blood.

PubMed

Kabra, P M; Wall, J H; Dimson, P

1987-12-01

In this rapid, precise, accurate, cost-effective, automated liquid-chromatographic procedure for determining cyclosporine in whole blood, the cyclosporine is extracted from 0.5 mL of whole blood together with 300 micrograms of cyclosporin D per liter, added as internal standard, by using an Advanced Automated Sample Processing unit. The on-line solid-phase extraction is performed on an octasilane sorbent cartridge, which is interfaced with a RP-8 guard column and an octyl analytical column, packed with 5-microns packing material. Both columns are eluted with a mobile phase containing acetonitrile/methanol/water (53/20/27 by vol) at a flow rate of 1.5 mL/min and column temperature of 70 degrees C. Absolute recovery of cyclosporine exceeded 85% and the standard curve was linear to 5000 micrograms/L. Within-run and day-to-day CVs were less than 8%. Correlation between automated and manual Bond-Elut extraction methods was excellent (r = 0.987). None of 18 drugs and four steroids tested interfered.

Enantioselective extraction of (+)-(S)-citalopram and its main metabolites using a tailor-made stir bar chiral imprinted polymer for their LC-ESI-MS/MS quantitation in urine samples.

PubMed

Unceta, Nora; Gómez-Caballero, Alberto; García, Deiene; Díaz, Goretti; Guerreiro, Antonio; Piletsky, Sergey; Goicolea, M Aránzazu; Barrio, Ramón J

2013-11-15

This paper reports the application of a chiral imprinted polymer (CIP)-coated stir bar for the selective extraction of (+)-(S)-citalopram (SCIT) and its main metabolites, (+)-(S)-desmethylcitalopram (SDCIT) and (+)-(S)-didesmethylcitalopram (SDDCIT), from urine samples. The developed device has been demonstrated to be capable of selectively extracting the three target analytes from urine samples without saturating the imprinted sites. A CIP-coated stir bar sorptive extraction procedure (CIP-SBSE) is proposed for the isolation of SCIT, SDCIT and SDDCIT followed by their subsequent analysis using liquid chromatography ion trap mass spectrometry (LC-ITMS). Deuterated SCIT-d6 was used as an internal standard. The method was validated using a standard procedure, which revealed that a quantification of 5 ng mL(-1) was obtained in urine samples and that the accuracy and precision were within the established values while no matrix effect was observed. Copyright © 2013 Elsevier B.V. All rights reserved.

Multi-Component Profiling of Trace Volatiles in Blood by Gas Chromatography/Mass Spectrometry with Dynamic Headspace Extraction

PubMed Central

Kakuta, Shoji; Yamashita, Toshiyuki; Nishiumi, Shin; Yoshida, Masaru; Fukusaki, Eiichiro; Bamba, Takeshi

2015-01-01

A dynamic headspace extraction method (DHS) with high-pressure injection is described. This dynamic extraction method has superior sensitivity to solid phase micro extraction, SPME and is capable of extracting the entire gas phase by purging the headspace of a vial. Optimization of the DHS parameters resulted in a highly sensitive volatile profiling system with the ability to detect various volatile components including alcohols at nanogram levels. The average LOD for a standard volatile mixture was 0.50 ng mL−1, and the average LOD for alcohols was 0.66 ng mL−1. This method was used for the analysis of volatile components from biological samples and compared with acute and chronic inflammation models. The method permitted the identification of volatiles with the same profile pattern as in vitro oxidized lipid-derived volatiles. In addition, the concentration of alcohols and aldehydes from the acute inflammation model samples were significantly higher than that for the chronic inflammation model samples. The different profiles between these samples could also be identified by this method. Finally, it was possible to analyze alcohols and low-molecular-weight volatiles that are difficult to analyze by SPME in high sensitivity and to show volatile profiling based on multi-volatile simultaneous analysis. PMID:26819905

Multi-Component Profiling of Trace Volatiles in Blood by Gas Chromatography/Mass Spectrometry with Dynamic Headspace Extraction.

PubMed

Kakuta, Shoji; Yamashita, Toshiyuki; Nishiumi, Shin; Yoshida, Masaru; Fukusaki, Eiichiro; Bamba, Takeshi

2015-01-01

A dynamic headspace extraction method (DHS) with high-pressure injection is described. This dynamic extraction method has superior sensitivity to solid phase micro extraction, SPME and is capable of extracting the entire gas phase by purging the headspace of a vial. Optimization of the DHS parameters resulted in a highly sensitive volatile profiling system with the ability to detect various volatile components including alcohols at nanogram levels. The average LOD for a standard volatile mixture was 0.50 ng mL(-1), and the average LOD for alcohols was 0.66 ng mL(-1). This method was used for the analysis of volatile components from biological samples and compared with acute and chronic inflammation models. The method permitted the identification of volatiles with the same profile pattern as in vitro oxidized lipid-derived volatiles. In addition, the concentration of alcohols and aldehydes from the acute inflammation model samples were significantly higher than that for the chronic inflammation model samples. The different profiles between these samples could also be identified by this method. Finally, it was possible to analyze alcohols and low-molecular-weight volatiles that are difficult to analyze by SPME in high sensitivity and to show volatile profiling based on multi-volatile simultaneous analysis.

[Simultaneous determination of 33 primary aromatic amines of free state in fine pigments by ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry].

PubMed

Man, Zhengyin; Wang, Quanlin; Li, Hesheng; Zhang, Aizhi

2014-12-01

A comprehensive analytical method based on ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC-MS/MS) has been developed for the simultaneous determination of 33 primary aromatic amines (PAAs) in fine pigments such as gouache paint, oil painting pigment and acrylic paint. The primary aromatic amines in samples were extracted with acetonitrile. Then the extract was concentrated by centrifugation and nitrogen blow, finally diluted to 2 mL with methanol-water (1:9, v/v) and filtered through 0. 22 im membrane before UPLC-MS/MS analysis. The analytes were separated on a BEH Phenyl column (100 mm x 2. 1 mm, 1. 7 1µm) with 0. 07% (v/v) formic acid in methanol-water as mobile phases in gradient elution. The PAAs were detected by UPLC-MS/MS under multiple reaction monitoring (MRM) mode and quantified by the internal standard method. The separation conditions, fragment voltages and collision energies were optimized. The impacts of extraction times, extraction solvents and concentration methods on recoveries were studied. The limits of detection and limits of quantitation for the 33 primary aromatic amines were 5-50 µg/kg and 15-150 µg/kg respectively. The mean recoveries of three different dye products at three spiked levels were 70. 1% - 115. 8%. The relative standard deviations were 2. 1% - 15%. The expenmental results indicated that the method is simple, rapid, sensitive, accurate and can meet the requirements for the determination.

Report: Comparison of qualitative, quantitative analysis and antioxidant potential between wild and cultivated Borago officinalis leaves from palestine.

PubMed

Abu-Qaoud, Hassan; Shawarb, Nuha; Hussen, Fatima; Jaradat, Nidal; Shtaya, Munqez

2018-05-01

Borago officinalis plant is an important plant of high medicinal and nutritional values. This study designed to evaluate antioxidant activity, screen the existence of phytogenic chemical compounds and to determine the total flavonoid and phenol contents of wild and cultivated Borago officinalis. Total flavonoid contents of the wild and cultivated Borago officinalis were determined by using rutin reference standard method and total phenols determined by using Folin Ciocalteu's method while antioxidant activity evaluated by using 2, 2-diphenyl-1-picryl-hydrazyl-hydrate assay. Phytochemical analyses indicated the presence of carbohydrate, phenols, flavonoids, phytosteroids tannins and volatile oil. The total flavonoid content of the methanolic extract from the wild borage plant was 22.4mg RU/g this value was reduced to 13.1mg RU/g for the cultivated methanolic extract as well as the total phenols contents was dropped from 5.21mg GA/g to 2.37mg GA/g methanolic extracts. Total tannins content of the wild growing borage plant was 13.7mg GA/g methanolic extract. This value was higher in the cultivated borage with 21.33mg GA/g methanolic extract. The wild leaves extract had IC 50 =6.3μg/mL for wild leaves extract was closer to IC 50 value of Trolox (standard reference with high antioxidant activity), while the cultivated leaves extract had higher IC 50 = 8.7μg/mL which mean lower antioxidant activity than the wild growing one. The data of this study showed that the extracts of Borago officinalis possess antioxidant and free radical scavenging activities. Variation was clear between wild and cultivated species, these findings propose that such plant extract could have a wide range of applications in both food and pharmaceutical industries. Therefore, more research is necessary to investigate different cultural practices on the efficiency of borage plant.

Extraction and analysis methods for the determination of pyrethroid insecticides in surface water, sediments and biological tissues at environmentally relevant concentrations.

PubMed

Mekebri, A; Crane, D B; Blondina, G J; Oros, D R; Rocca, J L

2008-05-01

The aim of this study was to develop and validate chemical methods for measuring pyrethroid insecticides at environmentally relevant concentrations in different matrices. The analytes included six synthetic pyrethroids with the highest agricultural and commercial structural uses in California: bifenthrin, cyfluthrin, cypermethrin, esfenvalerate/fenvalerate, lambda-cyhalothrin, permethrin, and their corresponding stereoisomers, which includes enantiomers, diastereomers and racemic mixtures. Fortified water samples were extracted for analysis of synthetic pyrethroids using liquid-liquid extraction, while fortified sediment and fish tissue samples were extracted using pressurized fluid extraction followed by gel permeation chromatography (GPC) to remove matrix interferences. A florisil column was used for additional cleanup and fractionation of sediment and tissue extracts. Extracts were analyzed using dual column high resolution gas chromatography with electron capture detection (GC/ECD) and confirmation was obtained with gas chromatography mass spectrometry using a quadrupole ion trap detector in MS-MS mode. Method detection limits (MDLs) have been established for water (1-3 ng/L), sediment (0.5-4 ng/g dry weight) and tissue (1-3 ng/g fresh weight). Mean percent recoveries of fortified blanks and samples ranged from 75 to 115% with relative standard deviation (RSD) values less than 20% for all target compounds.

Polyaniline-coated cigarette filters as a solid-phase extraction sorbent for the extraction and enrichment of polycyclic aromatic hydrocarbon in water samples.

PubMed

Bunkoed, Opas; Rueankaew, Thanaschaphorn; Nurerk, Piyaluk; Kanatharana, Proespichaya

2016-06-01

Polyaniline coated cigarette filters were successfully synthesized and used as a solid-phase extraction sorbent for the extraction and preconcentration of polycyclic aromatic hydrocarbons in water samples. The polyaniline helped to enhance the adsorption ability of polycyclic aromatic hydrocarbons on the sorbent through π-π interactions. The high porosity and large surface area of the cigarette filters helped to reduce backpressure and can be operated with high sample flow rate without loss of extraction efficiency. The developed sorbent was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The parameters that affected the extraction efficiencies, i.e. polymerization time, type of desorption solvent and its volume, sample flow rate, sample volume, sample pH, ionic strength, and organic modifier were investigated. Under the optimal conditions, the method was linear over the range of 0.5-10 μg/L and a detection limit of 0.5 ng/L. This simple, rapid, and cost-effective method was successfully applied to the preconcentration of polycyclic aromatic hydrocarbons from water samples. The developed method provided a high enrichment factor with good extraction efficiency (85-98%) and a relative standard deviation <10%. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

40 CFR 799.6786 - TSCA water solubility: Generator column method.

Code of Federal Regulations, 2010 CFR

2010-07-01

... quantitative) analysis of solvent extract in paragraph (c)(3)(iv) of this section. The design of the generator... partition coefficients of hydrophobic substances. Journal of Research, National Bureau of Standards, 86:361...

Preliminary study about the possible glycemic clinical advantage in using a fixed combination of Berberis aristata and Silybum marianum standardized extracts versus only Berberis aristata in patients with type 2 diabetes

PubMed Central

Di Pierro, Francesco; Putignano, Pietro; Villanova, Nicola; Montesi, Luca; Moscatiello, Simona; Marchesini, Giulio

2013-01-01

Background Berberine is an isoquinoline alkaloid widely used to improve the glucidic and lipidic profiles of patients with hypercholesterolemia, metabolic syndrome, and type 2 diabetes. The limitation of berberine seems to be its poor oral bioavailability, which is affected by the presence, in enterocytes, of P-glycoprotein – an active adenosine triphosphate (ATP)-consuming efflux protein that extrudes berberine into the intestinal lumen, thus limiting its absorption. According to some authors, silymarin, derived from Silybum marianum, could be considered a P-glycoprotein antagonist. Aim The study aimed to evaluate the role played by a possible P-glycoprotein antagonist (silymarin), when added to a product containing Berberis aristata extract, in terms of benefits to patients with type 2 diabetes. Methods The study enrolled 69 patients with type 2 diabetes in suboptimal glycemic control who were treated with diet, hypoglycemic drugs, and in cases of concomitant alterations of the lipid profile, hypolipidemic agents. The patients received an add-on therapy consisting of either a standardized extract of Berberis aristata (titrated in 85% berberine) corresponding to 1,000 mg/day of berberine, or Berberol®, a fixed combination containing the same standardized extract of Berberis aristata plus a standardized extract of Silybum marianum (titrated as >60% in silymarin), for a total intake of 1,000 mg/day of berberine and 210 mg/day of silymarin. Results Both treatments similarly improved fasting glucose, total cholesterol, low-density lipoprotein (LDL) cholesterol, triglyceride, and liver enzyme levels, whereas glycosylated hemoglobin (HbA1c) values were reduced to a greater extent by the fixed combination. Conclusion The association of berberine and silymarin demonstrated to be more effective than berberine alone in reducing HbA1c, when administered at the same dose and in the form of standardized extracts in type 2 diabetic patients. PMID:24277991

Sorptive thin film microextraction followed by direct solid state spectrofluorimetry: A simple, rapid and sensitive method for determination of carvedilol in human plasma.

PubMed

Karimi, Shima; Talebpour, Zahra; Adib, Noushin

2016-06-14

A poly acrylate-ethylene glycol (PA-EG) thin film is introduced for the first time as a novel polar sorbent for sorptive extraction method coupled directly to solid-state spectrofluorimetry without the necessity of a desorption step. The structure, polarity, fluorescence property and extraction performance of the developed thin film were investigated systematically. Carvedilol was used as the model analyte to evaluate the proposed method. The entire procedure involved one-step extraction of carvedilol from plasma using PA-EG thin film sorptive phase without protein precipitation. Extraction variables were studied in order to establish the best experimental conditions. Optimum extraction conditions were the followings: stirring speed of 1000 rpm, pH of 6.8, extraction temperature of 60 °C, and extraction time of 60 min. Under optimal conditions, extraction of carvedilol was carried out in spiked human plasma; and the linear range of calibration curve was 15-300 ng mL(-1) with regression coefficient of 0.998. Limit of detection (LOD) for the method was 4.5 ng mL(-1). The intra- and inter-day accuracy and precision of the proposed method were evaluated in plasma sample spiked with three concentration levels of carvedilol; yielding a recovery of 91-112% and relative standard deviation of less than 8%, respectively. The established procedure was successfully applied for quantification of carvedilol in plasma sample of a volunteer patient. The developed PA-EG thin film sorptive phase followed by solid-state spectrofluorimetric method provides a simple, rapid and sensitive approach for the analysis of carvedilol in human plasma. Copyright © 2016 Elsevier B.V. All rights reserved.

Validation of a pressurized solvent extraction and GC-NCI-MS method for the low level determination of 40 polybrominated diphenyl ethers in mothers' milk.

PubMed

Lacorte, Silvia; Guillamon, Míriam

2008-08-01

This study reports an efficient method for the determination of 40 PBDEs from mono- to hepta-brominated in human milk. Pressurized liquid extraction (PLE) was optimized to recover PBDEs in a quantitative way using 1g of freeze dried milk. Due to the great amount of coextracted compounds, the clean-up step was optimized using alumina SPE disposable cartridges of 2 and 5 g. Whereas 2g alumina SPE failed in providing good extraction yields, all PBDEs were satisfactorily recovered using 5 g alumina SPE cartridges. Detection was performed with gas chromatography coupled to mass spectrometry with negative chemical ionization and method detection limits ranged from 0.01 to 0.05 microg kg(-1) wet weight (ww) with a good intra and inter-day variation (coefficient of variation lower than 13.4%). This method was validated by participating in an interlaboratory exercise from Quasimeme (United Kingdom), where a standard solution containing seven congeners and a certified unspiked mothers' milk were analyzed. In the standard mixture, levels between 96.915 and 570.172 microg l(-1) were quantified, whereas in certified mothers' milk, BDEs 47, 99, 100 and 154 were detected at levels from 0.010 and 0.061 microg kg(-1) ww, with an error <30%. The applicability of the method was tested experimentally in five mothers' milk samples, where only BDE 47 was detected at a maximum concentration of 10.45 microg kg(-1) lipid weight (lw). PLE succeeded in extracting all PBDEs from the sample with good reproducibility although the clean-up step had to be severely performed to eliminate sample interferences such as milk lipids and proteins.

Analysis of amide compounds in different parts of Piper ovatum Vahl by high-performance liquid chromatographic

PubMed Central

Silva, Daniel R.; Brenzan, Mislaine A.; Kambara, Lauro M.; Cortez, Lucia E. R.; Cortez, Diógenes A. G.

2013-01-01

Background: Piper ovatum (Piperaceae) has been used in traditional medicine for the treatment of inflammations and as an analgesic. Previous studies have showed important biological activities of the extracts and amides from P. ovatum leaves. Objective: In this study, a high-performance liquid chromatographic (HPLC) method was developed and validated for quantitative determination of the amides in different parts of Piper ovatum. Materials and Methods: The analysis was carried out on a Metasil ODS column (150 × 4.6 mm, 5μm) at room temperature. HPLC conditions were as follows: acetonitrile (A), and water (B), 1.0% acetic acid. The gradient elution used was 0–30 min, 0-60% A; 30–40 min, 60% A. Flow rate used was 1.0mL/min, and detection at 280nm. Results: The validation using piperlonguminine, as the standard, demonstrated that the method shows linearity (linear correlation coefficient = 0.998), precision (relative standard deviation <5%) and accuracy (mean recovery = 103.78%) in the concentration range 31.25 – 500μg/mL. The limit of detection and quantification were 1.21 and 4.03μg/mL, respectively. This method allowed the identification and quantification of piperlonguminine and piperovatine in the hydroethanolic extracts of P. ovatum obtained from the leaves, stems and roots. All the extracts showed the same chromatographic profile. The leaves and roots contained the highest concentrations of piperlonguminine and the stems and leaves showed the most concentrations of piperovatine. Conclusion: This HPLC method is suitable for routine quantitative analysis of amides in extracts of Piper ovatum and phytopharmaceuticals containing this herb. PMID:24174818

Improved sample preparation of glyphosate and methylphosphonic acid by EPA method 6800A and time-of-flight mass spectrometry using novel solid-phase extraction.

PubMed

Wagner, Rebecca; Wetzel, Stephanie J; Kern, John; Kingston, H M Skip

2012-02-01

The employment of chemical weapons by rogue states and/or terrorist organizations is an ongoing concern in the United States. The quantitative analysis of nerve agents must be rapid and reliable for use in the private and public sectors. Current methods describe a tedious and time-consuming derivatization for gas chromatography-mass spectrometry and liquid chromatography in tandem with mass spectrometry. Two solid-phase extraction (SPE) techniques for the analysis of glyphosate and methylphosphonic acid are described with the utilization of isotopically enriched analytes for quantitation via atmospheric pressure chemical ionization-quadrupole time-of-flight mass spectrometry (APCI-Q-TOF-MS) that does not require derivatization. Solid-phase extraction-isotope dilution mass spectrometry (SPE-IDMS) involves pre-equilibration of a naturally occurring sample with an isotopically enriched standard. The second extraction method, i-Spike, involves loading an isotopically enriched standard onto the SPE column before the naturally occurring sample. The sample and the spike are then co-eluted from the column enabling precise and accurate quantitation via IDMS. The SPE methods in conjunction with IDMS eliminate concerns of incomplete elution, matrix and sorbent effects, and MS drift. For accurate quantitation with IDMS, the isotopic contribution of all atoms in the target molecule must be statistically taken into account. This paper describes two newly developed sample preparation techniques for the analysis of nerve agent surrogates in drinking water as well as statistical probability analysis for proper molecular IDMS. The methods described in this paper demonstrate accurate molecular IDMS using APCI-Q-TOF-MS with limits of quantitation as low as 0.400 mg/kg for glyphosate and 0.031 mg/kg for methylphosphonic acid. Copyright © 2012 John Wiley & Sons, Ltd.

Development and validation of a micellar electrokinetic chromatography method for quantitative determination of butenolides in Piper malacophyllum (C. Presl) C. DC.

PubMed

de Oliveira, Alberto; Silva, Claudinei A; Silva, Adalberto M; Tavares, Marina F M; Kato, Massuo J

2010-01-01

A large number of natural and synthetic compounds having butenolides as a core unit have been described and many of them display a wide range of biological activities. Butenolides from P. malacophyllum have presented potential antifungal activities but no specific, fast, and precise method has been developed for their determination. To develop a methodology based on micellar electrokinetic chromatography to determine butenolides in Piper species. The extracts were analysed in an uncoated fused-silica capillaries and for the micellar system 20 mmol/L SDS, 20% (v/v) acetonitrile (ACN) and 10 mmol/L STB aqueous buffer at pH 9.2 were used. The method was validated for precision, linearity, limit of detection (LOD) and limit of quantitation (LOQ) and the standard deviations were determined from the standard errors estimated by the regression line. A micellar electrokinetic chromatography (MEKC) method for determination of butenolides in extracts gave full resolution for 1 and 2. The analytical curve in the range 10.0-50.0 µg/mL (r(2) = 0.999) provided LOD and LOQ for 1 and 2 of 2.1/6.3 and 1.1/3.5 µg/mL, respectively. The RSD for migration times were 0.12 and 1.0% for peak area ratios with 100.0 ± 1.4% of recovery. A novel high-performance MEKC method developed for the analysis of butenolides 1 and 2 in leaf extracts of P. malacophyllum allowed their quantitative determined within an analysis time shorter than 5 min and the results indicated CE to be a feasible analytical technique for the quantitative determination of butenolides in Piper extracts. Copyright © 2010 John Wiley & Sons, Ltd.

Ion Chromatography as an Alternative to Standard Methods for Analysis of Macro-nutrients in Mehlich 1 Extracts of Unfertilized Forest Soils

Treesearch

Joseph B. Fischer; James H. Miller

2004-01-01

This study evaluates ion chromatography (IC) as an alternative to atomic absorption (AA) and inductively-coupled plasma spectromctry (ICP) for analysis of potassium (K), magnesium (Mg), and calcium (Ca), and and as an alternative to antimonylmolybdate colorimetry and ICP for analysis of phosphorus (P) macro-nutrients in Mehlich 1 extracts. Soils typical of pine forests...

Determination of guaifenesin in human serum by capillary gas chromatography and electron capture detection.

PubMed

Sharaf, Maged H M; Stiff, Dwight D

2004-06-29

A method for the quantitation of guaifenesin in human serum has been developed and validated. The procedure involves liquid-liquid extraction of the serum sample in the presence of mephenesin as an internal standard, followed by derivatization and analysis using capillary gas chromatography (GC) and electron capture detection (ECD). Different solvents were tested for extraction of guaifenesin from serum. n-Hexane/dichloromethane (1:1, v/v) gave the highest recovery and the lowest background and was chosen as the extraction solvent. After extraction, the residue of guaifenesin was derivatized at 60 degrees C for 30 min, with trifluoroacetic acid anhydride (TFAA) in toluene in the presence of pyridine. Excess trifluoroacetic acid anhydride was removed using dilute solution of ammonium hydroxide. The method proved to be linear over the range of 25.0-1000 ng/ml. Recovery of guaifenesin from spiked samples was consistent, averaging 75.5% at 50.0 ng/ml with a range of 72.0-80.0% (N = 8 determinations) and averaging 78% at 800 ng/ml with a range of 76.0-81.0% (N = 8 determinations). The internal standard recovery was also consistent averaging 72.8% with a range of 67.0-76.0% (N = 16 determinations). Copyright 2004 Elsevier B.V.

Determination of volatile organic acids in oriental tobacco by needle-based derivatization headspace liquid-phase microextraction coupled to gas chromatography/mass spectrometry.

PubMed

Sun, Shi-Hao; Xie, Jian-Ping; Xie, Fu-Wei; Zong, Yong-Li

2008-02-01

A method coupling needle-based derivatization headspace liquid-phase microextraction with gas chromatography-mass spectrometry (HS-LPME/GC-MS) was developed to determine volatile organic acids in tobacco. The mixture of N,O-bis(trimethylsilyl)trifluoroacetamide and decane was utilized as the solvent for HS-LPME, resulting that extraction and derivatization were simultaneously completed in one step. The solvent served two purposes. First, it pre-concentrated volatile organic acids in the headspace of tobacco sample. Second, the volatile organic acids extracted were derivatized to form silyl derivatives in the drop. The main parameters affecting needle-based derivatization HS-LPME procedure such as extraction and derivatization reagent, microdrop volume, extraction and derivatization time, and preheating temperature and preheating time were optimized. The standard addition approach was essential to obtain accurate measurements by minimizing matrix effects. Good linearity (R(2)> or =0.9804) and good repeatability (RSDs< or =15.3%, n=5) for 16 analytes in spiked standard analytes sample were achieved. The method has the additional advantages that at the same time it is simple, fast, effective, sensitive, selective, and provides an overall profile of volatile organic acids in the oriental tobacco. This paper does offer an alternative approach to determine volatile organic acids in tobacco.

[Determination of fatty acid esters of chloropropanediols in diet samples by gas chromatography-mass spectrometry coupled with solid-supported liquid-liquid extraction].

PubMed

Gao, Jie; Liu, Qing; Han, Feng; Miao, Hong; Zhao, Yunfeng; Wu, Yongning

2014-05-01

To establish a method for the determination of fatty acid esters of 3-monochloropropane-1, 2-diol (3-MCPD) and 2-monochloropropane-1, 3-diol (2-MCPD) in diet samples by gas chromatography-mass spectrometry (GC-MS) with solid-supported liquid-liquid extraction (SLE). Diet samples were ultrasonically extracted by hexane, followed by ester cleavage reaction with sodium methylate in methanol, and then purified by solid-supported liquid-liquid extraction. (SLE) using diatomaceous earth as the sorbent. After derivatization with heptafluorobutyrylimidazole, the analytes were detected by GC-MS and quantified by the deuterated internal standards. The limits of detection (LODs) of 3-MCPD esters and 2-MCPD esters in different diet samples were 0.002 - 0.005 mg/kg and 0.002 - 0.006 mg/kg. The average recoveries of 3-MCPD esters and 2-MCPD esters at the spiking levels of 0.05 and 0.1 mg/kg in the diet samples were in the range of 65.9% - 104.2% and 75.4% - 118.0%, respectively, with the relative standard deviations in the range of 2.2% - 14.2% and 0.8% - .13.9%. The method is simple, accurate and rugged for the determination of fatty acid esters of 3-MCPD and 2-MCPD in diet samples.

A new strategy for accelerated extraction of target compounds using molecularly imprinted polymer particles embedded in a paper-based disk.

PubMed

Zarejousheghani, Mashaalah; Schrader, Steffi; Möder, Monika; Schmidt, Matthias; Borsdorf, Helko

2018-03-01

In this study, a general simple and inexpensive method is introduced for the preparation of a paper-based selective disk-type solid phase extraction (SPE) technique, appropriate for fast and high throughput monitoring of target compounds. An ion exchange molecularly imprinted polymer (MIP) was synthesized for the extraction and analysis of acesulfame, an anthropogenic water quality marker. Acesulfame imprinting was used as an example for demonstrating the benefits of a nanosized, swellable MIP extraction sorbents integrated in an on-site compatible concept for water quality monitoring. Compared with an 8 mL standard SPE cartridge, the paper-based MIP disk (47 mm ø) format allowed (1) high sample flow rates up to 30 mL•min -1 without losing extraction efficiency (2) extracting sample volumes up to 500 mL in much shorter times than with standard SPE, (3) the reuse of the disks (up to 3 times more than SPE cartridge) due to high robustness and an efficient post-cleaning, and (4) reducing the sampling time from 100 minutes (using the standard SPE format) to about 2 minutes with the MIP paper disk for 50 mL water sample. Different parameters like cellulose fiber/polymer ratios, sample volume, sample flow-rate, washing, and elution conditions were evaluated and optimized. Using developed extraction technique with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS-MS) analysis, a new protocol was established that provides detection and quantification limits of 0.015 μg•L -1 and 0.05 μg•L -1 , respectively. The developed paper disks were used in-field for the selective extraction of target compounds and transferred to the laboratory for further analysis. Copyright © 2017 John Wiley & Sons, Ltd.

Inhibitory activity of a standardized elderberry liquid extract against clinically-relevant human respiratory bacterial pathogens and influenza A and B viruses

PubMed Central

2011-01-01

Background Black elderberries (Sambucus nigra L.) are well known as supportive agents against common cold and influenza. It is further known that bacterial super-infection during an influenza virus (IV) infection can lead to severe pneumonia. We have analyzed a standardized elderberry extract (Rubini, BerryPharma AG) for its antimicrobial and antiviral activity using the microtitre broth micro-dilution assay against three Gram-positive bacteria and one Gram-negative bacteria responsible for infections of the upper respiratory tract, as well as cell culture experiments for two different strains of influenza virus. Methods The antimicrobial activity of the elderberry extract was determined by bacterial growth experiments in liquid cultures using the extract at concentrations of 5%, 10%, 15% and 20%. The inhibitory effects were determined by plating the bacteria on agar plates. In addition, the inhibitory potential of the extract on the propagation of human pathogenic H5N1-type influenza A virus isolated from a patient and an influenza B virus strain was investigated using MTT and focus assays. Results For the first time, it was shown that a standardized elderberry liquid extract possesses antimicrobial activity against both Gram-positive bacteria of Streptococcus pyogenes and group C and G Streptococci, and the Gram-negative bacterium Branhamella catarrhalis in liquid cultures. The liquid extract also displays an inhibitory effect on the propagation of human pathogenic influenza viruses. Conclusion Rubini elderberry liquid extract is active against human pathogenic bacteria as well as influenza viruses. The activities shown suggest that additional and alternative approaches to combat infections might be provided by this natural product. PMID:21352539

Simultaneous Determination of Perfluorinated Compounds in Edible Oil by Gel-Permeation Chromatography Combined with Dispersive Solid-Phase Extraction and Liquid Chromatography-Tandem Mass Spectrometry.

PubMed

Yang, Lili; Jin, Fen; Zhang, Peng; Zhang, Yanxin; Wang, Jian; Shao, Hua; Jin, Maojun; Wang, Shanshan; Zheng, Lufei; Wang, Jing

2015-09-30

A simple analytical method was developed for the simultaneous analysis of 18 perfluorinated compounds (PFCs) in edible oil. The target compounds were extracted by acetonitrile, purified by gel permeation chromatography (GPC) and dispersive solid-phase extraction (DSPE) using graphitized carbon black (GCB) and octadecyl (C18), and analyzed by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ES-MS/MS) in negative ion mode. Recovery studies were performed at three fortification levels. The average recoveries of all target PFCs ranged from 60 to 129%, with an acceptable relative standard deviation (RSD) (1-20%, n = 3). The method detection limits (MDLs) ranged from 0.004 to 0.4 μg/kg, which was significantly improved compared with the existing liquid-liquid extraction and cleanup method. The method was successfully applied for the analysis of all target PFCs in edible oil samples collected from markets in Beijing, China, and the results revealed that C6-C10 perfluorocarboxylic acid (PFCAs) and C7 perfluorosulfonic acid PFSAs were the major PFCs detected in oil samples.

Evaluation of a modified QuEChERS extraction of multiple classes of pesticides from a rice paddy soil by LC-APCI-MS/MS.

PubMed

Caldas, Sergiane S; Bolzan, Cátia M; Cerqueira, Maristela B; Tomasini, Débora; Furlong, Eliana B; Fagundes, Carlos; Primel, Ednei G

2011-11-23

A new method for the determination of clomazone, fipronil, tebuconazole, propiconazole, and azoxystrobin in samples of rice paddy soil is presented. The extraction of the pesticides from soil samples was performed by using a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method. Some extraction conditions such as salt addition, sample acidification, use of buffer, and cleanup step were evaluated. The optimized method dealt with a single extraction of the compounds under study with acidified acetonitrile, followed by the addition of MgSO(4) and NaCl prior to the final determination by liquid chromatography-atmospheric chemical pressure ionization-tandem mass spectrometry. Validation studies were carried out in soil samples. Recoveries of the spiked samples ranged between 70.3 and 120% with relative standard deviation lower than 18.2%. The limits of quantification were between 10 and 50 μg kg(-1). The method was applied to the analysis of real samples of soils where rice is cultivated.

Development of a low-cost method of analysis for the qualitative and quantitative analysis of butyltins in environmental samples.

PubMed

Bangkedphol, Sornnarin; Keenan, Helen E; Davidson, Christine; Sakultantimetha, Arthit; Songsasen, Apisit

2008-12-01

Most analytical methods for butyltins are based on high resolution techniques with complicated sample preparation. For this study, a simple application of an analytical method was developed using High Performance Liquid Chromatography (HPLC) with UV detection. The developed method was studied to determine tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT) in sediment and water samples. The separation was performed in isocratic mode on an ultra cyanopropyl column with a mobile phase of hexane containing 5% THF and 0.03% acetic acid. This method was confirmed using standard GC/MS techniques and verified by statistical paired t-test method. Under the experimental conditions used, the limit of detection (LOD) of TBT and DBT were 0.70 and 0.50 microg/mL, respectively. The optimised extraction method for butyltins in water and sediment samples involved using hexane containing 0.05-0.5% tropolone and 0.2% sodium chloride in water at pH 1.7. The quantitative extraction of butyltin compounds in a certified reference material (BCR-646) and naturally contaminated samples was achieved with recoveries ranging from 95 to 108% and at %RSD 0.02-1.00%. This HPLC method and optimum extraction conditions were used to determine the contamination level of butyltins in environmental samples collected from the Forth and Clyde canal, Scotland, UK. The values obtained severely exceeded the Environmental Quality Standard (EQS) values. Although high resolution methods are utilised extensively for this type of research, the developed method is cheaper in both terms of equipment and running costs, faster in analysis time and has comparable detection limits to the alternative methods. This is advantageous not just as a confirmatory technique but also to enable further research in this field.

Magnetic/non-magnetic argan press cake nanocellulose for the selective extraction of sudan dyes in food samples prior to the determination by capillary liquid chromatograpy.

PubMed

Benmassaoud, Yassine; Villaseñor, María J; Salghi, Rachid; Jodeh, Shehdeh; Algarra, Manuel; Zougagh, Mohammed; Ríos, Ángel

2017-05-01

Two methods for the determination of Sudan dyes (Sudan I, Sudan II, Sudan III and Sudan IV) in food samples, by solid phase extraction - capillary liquid chromatography, are proposed. Both methods use nanocellulose (NC) extracted from bleached argan press cake (APC), as a nano-adsorbent recycled from an agricultural waste material. One of the methods involves the dispersion of NC in food sample extracts, along with the waste and eluents being separated by centrifugation. In the other method, NC was modified by magnetic iron nanoparticles before using it in the extraction of Sudan dyes. The use of a magnetic component in the extraction process allows magnetic separation to replace the centrifugation step in a convenient and economical way. The two proposed methods allows the determination of Sudan dye amounts at the 0.25-2.00µgL -1 concentration range. The limit of detections, limit of quantifications and standard deviations achieved were lower than 0.1µgL -1 , 0.20µgL -1 and 3.46% respectively, when using NC as a nano-adsorbent, and lower than 0.07µgL -1 , 0.23µgL -1 and 2.62%, respectively, with the magnetic nanocellulose (MNC) was used. Both methods were applied to the determination of Sudan dyes in barbeque and ketchup sauce samples, obtaining recoveries between 93.4% and 109.6%. Copyright © 2017 Elsevier B.V. All rights reserved.

Profiling LC-DAD-ESI-TOF MS method for the determination of phenolic metabolites from avocado (Persea americana).

PubMed

Hurtado-Fernández, Elena; Carrasco-Pancorbo, Alegría; Fernández-Gutiérrez, Alberto

2011-03-23

A powerful HPLC-DAD-ESI-TOF MS method was established for the efficient identification of the chemical constituents in the methanolic extracts of avocado (Persea americana). Separation and detection conditions were optimized by using a standard mix containing 39 compounds belonging to phenolic acids and different categories of flavonoids, analytes that could be potentially present in the avocado extracts. Optimum LC separation was achieved on a Zorbax Eclipse Plus C18 analytical column (4.6×150 mm, 1.8 μm particle size) by gradient elution with water+acetic acid (0.5%) and acetonitrile as mobile phases, at a flow rate of 1.6 mL/min. The detection was carried out by ultraviolet-visible absorption and ESI-TOF MS. The developed method was applied to the study of 3 different varieties of avocado, and 17 compounds were unequivocally identified with standards. Moreover, around 25 analytes were tentatively identified by taking into account the accuracy and isotopic information provided by TOF MS.

Enantiomeric determination of DOPA in dietary supplements containing Mucuna pruriens by liquid chromatography/mass spectrometry.

PubMed

Hasegawa, Takashi; Takahashi, Kazunaga; Fukiwake, Tomohide; Saijo, Masaaki; Motoki, Yuji

2013-01-01

We developed a simple and rapid liquid chromatography/mass spectrometry (LC/MS) method for the enantiomeric determination of DOPA in dietary supplements containing Mucuna pruriens. L- and D-DOPA were ultrasonically extracted with 1% formic acid aqueous solution. The isolated extracts were analyzed by LC/MS using a Crownpak CR (-) column at 30℃. The mass spectrometer was operated in the positive mode of electrospray ionization, and the mobile phase was aqueous formic acid (pH 2.0). L-DOPA-ring-d3 was used as an internal standard. The method was validated for a dietary supplement spiked with L- and D-DOPA at 50 and 500 μg/g, respectively, and the recoveries of the DOPA enantiomers were between 97.5% and 101.3%. Relative standard deviation values of repeatability and intermediate precision were less than 7%. The method was applied to 14 dietary supplements. L-DOPA was detected in these supplements in the range of 0.88-12.8 mg/unit. D-DOPA was not detected.

Optimized Extraction of Polysaccharides from Grateloupia livida (Harv.) Yamada and Biological Activities.

PubMed

Ye, Danyan; Jiang, Zebin; Zheng, Fuchun; Wang, Hongmei; Zhang, Yanmei; Gao, Fenfei; Chen, Peihong; Chen, Yicun; Shi, Ganggang

2015-09-16

Polysaccharides from Grateloupia livida (Harv.) Yamada (GL) were extracted by a heating circumfluence method. Single-factor experiments were performed for the three parameters: extraction time (X₁), extraction temperature (X₂) and the ratio of water to raw material (X₃) and their test range. From preliminary experimental results, one type of the response surface methodology, the Box-Behnken design was applied for the optimizing polysaccharide extraction conditions. The experimental data obtained were fitted to a second-order polynomial equation. The optimal conditions were extraction time 5 h, extraction temperature 100 °C and ratio of water to raw material 70 mL/g. Under these conditions, the experimental yield was 39.22% ± 0.09%, which well matched the predicted value (39.25%), with 0.9774 coefficient of determination (R²). GL polysaccharides had scavenging activities for DPPH and hydroxyl radicals in vitro. The scavenging rates for both radicals peaked at 20 mg/mL GL concentration. However, the positive standard, VC (ascorbic acid), possessed stronger antioxidant activities than GL polysaccharides. Furthermore, the anticancer activity of GL polysaccharides on HepG2 cell proliferation increased dose- and time-dependently, but the positive standard, 5-fluorouracil (5-fu) showed more significant anticancer activity in this study. Overall, GL polysaccharides may have potential applications in the medical and food industries.

An isotope-dilution standard GC/MS/MS method for steroid hormones in water

USGS Publications Warehouse

Foreman, William T.; Gray, James L.; ReVello, Rhiannon C.; Lindley, Chris E.; Losche, Scott A.

2013-01-01

An isotope-dilution quantification method was developed for 20 natural and synthetic steroid hormones and additional compounds in filtered and unfiltered water. Deuterium- or carbon-13-labeled isotope-dilution standards (IDSs) are added to the water sample, which is passed through an octadecylsilyl solid-phase extraction (SPE) disk. Following extract cleanup using Florisil SPE, method compounds are converted to trimethylsilyl derivatives and analyzed by gas chromatography with tandem mass spectrometry. Validation matrices included reagent water, wastewater-affected surface water, and primary (no biological treatment) and secondary wastewater effluent. Overall method recovery for all analytes in these matrices averaged 100%; with overall relative standard deviation of 28%. Mean recoveries of the 20 individual analytes for spiked reagent-water samples prepared along with field samples analyzed in 2009–2010 ranged from 84–104%, with relative standard deviations of 6–36%. Detection levels estimated using ASTM International’s D6091–07 procedure range from 0.4 to 4 ng/L for 17 analytes. Higher censoring levels of 100 ng/L for bisphenol A and 200 ng/L for cholesterol and 3-beta-coprostanol are used to prevent bias and false positives associated with the presence of these analytes in blanks. Absolute method recoveries of the IDSs provide sample-specific performance information and guide data reporting. Careful selection of labeled compounds for use as IDSs is important because both inexact IDS-analyte matches and deuterium label loss affect an IDS’s ability to emulate analyte performance. Six IDS compounds initially tested and applied in this method exhibited deuterium loss and are not used in the final method.

Comparison of GC-MS and FTIR methods for quantifying naphthenic acids in water samples.

PubMed

Scott, Angela C; Young, Rozlyn F; Fedorak, Phillip M

2008-11-01

The extraction of bitumen from the oil sands in Canada releases toxic naphthenic acids into the process-affected waters. The development of an ideal analytical method for quantifying naphthenic acids (general formula C(n)H(2n+Z)O(2)) has been impeded by the complexity of these mixtures and the challenges of differentiating naphthenic acids from other naturally-occurring organic acids. The oil sands industry standard FTIR method was compared with a newly-developed GC-MS method. Naphthenic acids concentrations were measured in extracts of surface and ground waters from locations within the vicinity of and away from the oil sands deposits and in extracts of process-affected waters. In all but one case, FTIR measurements of naphthenic acids concentrations were greater than those determined by GC-MS. The detection limit of the GC-MS method was 0.01 mg L(-1) compared to 1 mg L(-1) for the FTIR method. The results indicated that the GC-MS method is more selective for naphthenic acids, and that the FTIR method overestimates their concentrations.

A Statistical Review of Alternative Zinc and Copper Extraction from Mineral Fertilizers and Industrial By-Products.

PubMed

Cenciani de Souza, Camila Prado; Aparecida de Abreu, Cleide; Coscione, Aline Renée; Alberto de Andrade, Cristiano; Teixeira, Luiz Antonio Junqueira; Consolini, Flavia

2018-01-01

Rapid, accurate, and low-cost alternative analytical methods for micronutrient quantification in fertilizers are fundamental in QC. The purpose of this study was to evaluate whether zinc (Zn) and copper (Cu) content in mineral fertilizers and industrial by-products determined by the alternative methods USEPA 3051a, 10% HCl, and 10% H2SO4 are statistically equivalent to the standard method, consisting of hot-plate digestion using concentrated HCl. The commercially marketed Zn and Cu sources in Brazil consisted of oxides, carbonate, and sulfate fertilizers and by-products consisting of galvanizing ash, galvanizing sludge, brass ash, and brass or scrap slag. The contents of sources ranged from 15 to 82% and 10 to 45%, respectively, for Zn and Cu. The Zn and Cu contents refer to the variation of the elements found in the different sources evaluated with the concentrated HCl method as shown in Table 1. A protocol based on the following criteria was used for the statistical analysis assessment of the methods: F-test modified by Graybill, t-test for the mean error, and linear correlation coefficient analysis. In terms of equivalents, 10% HCl extraction was equivalent to the standard method for Zn, and the results of the USEPA 3051a and 10% HCl methods indicated that these methods were equivalents for Cu. Therefore, these methods can be considered viable alternatives to the standard method of determination for Cu and Zn in mineral fertilizers and industrial by-products in future research for their complete validation.

Low Cost Design of an Advanced Encryption Standard (AES) Processor Using a New Common-Subexpression-Elimination Algorithm

NASA Astrophysics Data System (ADS)

Chen, Ming-Chih; Hsiao, Shen-Fu

In this paper, we propose an area-efficient design of Advanced Encryption Standard (AES) processor by applying a new common-expression-elimination (CSE) method to the sub-functions of various transformations required in AES. The proposed method reduces the area cost of realizing the sub-functions by extracting the common factors in the bit-level XOR/AND-based sum-of-product expressions of these sub-functions using a new CSE algorithm. Cell-based implementation results show that the AES processor with our proposed CSE method has significant area improvement compared with previous designs.

Algorithms and applications of aberration correction and American standard-based digital evaluation in surface defects evaluating system

NASA Astrophysics Data System (ADS)

Wu, Fan; Cao, Pin; Yang, Yongying; Li, Chen; Chai, Huiting; Zhang, Yihui; Xiong, Haoliang; Xu, Wenlin; Yan, Kai; Zhou, Lin; Liu, Dong; Bai, Jian; Shen, Yibing

2016-11-01

The inspection of surface defects is one of significant sections of optical surface quality evaluation. Based on microscopic scattering dark-field imaging, sub-aperture scanning and stitching, the Surface Defects Evaluating System (SDES) can acquire full-aperture image of defects on optical elements surface and then extract geometric size and position information of defects with image processing such as feature recognization. However, optical distortion existing in the SDES badly affects the inspection precision of surface defects. In this paper, a distortion correction algorithm based on standard lattice pattern is proposed. Feature extraction, polynomial fitting and bilinear interpolation techniques in combination with adjacent sub-aperture stitching are employed to correct the optical distortion of the SDES automatically in high accuracy. Subsequently, in order to digitally evaluate surface defects with American standard by using American military standards MIL-PRF-13830B to judge the surface defects information obtained from the SDES, an American standard-based digital evaluation algorithm is proposed, which mainly includes a judgment method of surface defects concentration. The judgment method establishes weight region for each defect and adopts the method of overlap of weight region to calculate defects concentration. This algorithm takes full advantage of convenience of matrix operations and has merits of low complexity and fast in running, which makes itself suitable very well for highefficiency inspection of surface defects. Finally, various experiments are conducted and the correctness of these algorithms are verified. At present, these algorithms have been used in SDES.

Application of Box-Behnken experimental design to optimize the extraction of insecticidal Cry1Ac from soil.

PubMed

Li, Yan-Liang; Fang, Zhi-Xiang; You, Jing

2013-02-20

A validated method for analyzing Cry proteins is a premise to study the fate and ecological effects of contaminants associated with genetically engineered Bacillus thuringiensis crops. The current study has optimized the extraction method to analyze Cry1Ac protein in soil using a response surface methodology with a three-level-three-factor Box-Behnken experimental design (BBD). The optimum extraction conditions were at 21 °C and 630 rpm for 2 h. Regression analysis showed a good fit of the experimental data to the second-order polynomial model with a coefficient of determination of 0.96. The method was sensitive and precise with a method detection limit of 0.8 ng/g dry weight and relative standard deviations at 7.3%. Finally, the established method was applied for analyzing Cry1Ac protein residues in field-collected soil samples. Trace amounts of Cry1Ac protein were detected in the soils where transgenic crops have been planted for 8 and 12 years.

The Study of Residential Areas Extraction Based on GF-3 Texture Image Segmentation

NASA Astrophysics Data System (ADS)

Shao, G.; Luo, H.; Tao, X.; Ling, Z.; Huang, Y.

2018-04-01

The study chooses the standard stripe and dual polarization SAR images of GF-3 as the basic data. Residential areas extraction processes and methods based upon GF-3 images texture segmentation are compared and analyzed. GF-3 images processes include radiometric calibration, complex data conversion, multi-look processing, images filtering, and then conducting suitability analysis for different images filtering methods, the filtering result show that the filtering method of Kuan is efficient for extracting residential areas, then, we calculated and analyzed the texture feature vectors using the GLCM (the Gary Level Co-occurrence Matrix), texture feature vectors include the moving window size, step size and angle, the result show that window size is 11*11, step is 1, and angle is 0°, which is effective and optimal for the residential areas extracting. And with the FNEA (Fractal Net Evolution Approach), we segmented the GLCM texture images, and extracted the residential areas by threshold setting. The result of residential areas extraction verified and assessed by confusion matrix. Overall accuracy is 0.897, kappa is 0.881, and then we extracted the residential areas by SVM classification based on GF-3 images, the overall accuracy is less 0.09 than the accuracy of extraction method based on GF-3 Texture Image Segmentation. We reached the conclusion that residential areas extraction based on GF-3 SAR texture image multi-scale segmentation is simple and highly accurate. although, it is difficult to obtain multi-spectrum remote sensing image in southern China, in cloudy and rainy weather throughout the year, this paper has certain reference significance.

Determination of triazine herbicides in fresh vegetables by dynamic microwave-assisted extraction coupled with homogeneous ionic liquid microextraction high performance liquid chromatography.

PubMed

Wu, Lijie; Hu, Mingzhu; Li, Zhanchao; Song, Ying; Yu, Cui; Zhang, Yupu; Zhang, Hanqi; Yu, Aimin; Ma, Qiang; Wang, Ziming

2015-02-01

A novel extraction method, dynamic microwave-assisted extraction coupled with homogeneous ionic liquid microextraction, was developed for the determination of triazine herbicides, including desmetryn, terbumeton, propazine, terbuthylazine, dimethametryn, and dipropetryn in fresh vegetable samples by high performance liquid chromatography (HPLC). In the developed method, 120 μL of 1-butyl-3-methylimidazolium tetrafluoroborate ([C4MIM][BF4]) was added to 10 mL of aqueous solution containing 0.3 g of NaCl to obtained the extraction solvent. Six triazines could be extracted completely within 4 min by the present method. Then, [NH4][PF6] was added into the extract to form a water-insoluble ionic liquid [C4MIM][PF6] via a simple metathesis reaction, and the analytes were enriched into the ionic liquid phase. After centrifugation and dilution with acetonitrile, the resulting solution was analyzed directly by HPLC. The effects of some experimental parameters, including type and volume of ionic liquid, volume of extraction solvent, amount of ion-pairing agent [NH4][PF6], salt concentration, microwave power, and flow rate of extraction solvent on the extraction efficiency were investigated and optimized. Under the optimum experimental conditions, the linearity for determining the analytes was in the range of 2.50-250.00 μg kg(-1), with the correlation coefficients ranging from 0.9989 to 0.9999. When the present method was applied to the analysis of vegetable samples, satisfactory recoveries were obtained in the range of 76.8%-106.9%, and relative standard deviations were lower than 9.8%.

A method for the low-level (ng/g) determination of perfluorooctanoate in carpet by LC-MS-MS using matrix extracted standards.

PubMed

L'Empereur, Karen; Stadalius, Marilyn; Zhu, Yongdong; Mansoori, Bashir A; Isemura, Tsuguhide; Kaiser, Mary A; Knaup, Wolfgang; Noguchi, Masahiro

2008-08-01

Fluorotelomer-based acrylic polymers are applied to the surface of carpet to impart oil, stain, and water repellence properties. Concerns that fluorotelomer-based polymers are a possible source of "low level" exposure to humans, coupled with their widespread use have prompted the need to develop a method to detect and measure perfluorooctanoate (PFO) in carpet. A liquid chromatography tandem mass spectrometry method for the determination of PFO in carpet using a dual labeled 13C-perfluoroctanoic acid (13C-PFOA) internal standard is successfully developed and validated. Levels of PFO are determined using a gradient, reversed-phase high-performance liquid chromatography (HPLC) method with acetic acid acidified water-methanol, separated on a 50 mm Phenomenex Synergi Polar RP column. Ions monitored are 413 (parent) and 369 (daughter) for PFO and 415 (parent) and 370 (daughter) for dual labeled 13C-PFOA internal standard. Accuracy and precision over three days for 5 to 900 ng/g PFO in carpet ranged from 2.4% to 7.6% and 3.7% to 14.1%, respectively. Overall extraction efficiency for samples (n=30) fortified with 13C-PFOA at 20 ng/g and perfluorooctanoic acid (PFOA) at 5, 50, and 500 ng/g is 98.9%+/-8.1%. Specificity of the method was evaluated with two different carpet samples.

Antinociceptive and anti-inflammatory effects of Urtica dioica leaf extract in animal models

PubMed Central

Hajhashemi, Valiollah; Klooshani, Vahid

2013-01-01

Objective: This study was aimed to examine the antinociceptive and anti-inflammatory effects of Urtica dioica leaf extract in animal models. Materials and Methods: Hydroalcoholic extract of the plant leaves was prepared by percolation method. Male Swiss mice (25-35 g) and male Wistar rats (180-200 g) were randomly distributed in control, standard drug, and three experimental groups (n=6 in each group). Acetic acid-induced writhing, formalin test, and carrageenan-induced paw edema were used to assess the antinociceptive and anti-inflammatory effects. Results: The extract dose-dependently reduced acetic acid-induced abdominal twitches. In formalin test, the extract at any of applied doses (100, 200, and 400 mg/kg) could not suppress the licking behavior of first phase while doses of 200 and 400 mg/kg significantly inhibited the second phase of formalin test. In carrageenan test, the extract at a dose of 400 mg/kg significantly inhibited the paw edema by 26%. Conclusion: The results confirm the folkloric use of the plant extract in painful and inflammatory conditions. Further studies are needed to characterize the active constituents and the mechanism of action of the plant extract. PMID:25050274

Development and Validation of a Sensitive Method for Trace Nickel Determination by Slotted Quartz Tube Flame Atomic Absorption Spectrometry After Dispersive Liquid-Liquid Microextraction.

PubMed

Yolcu, Şükran Melda; Fırat, Merve; Chormey, Dotse Selali; Büyükpınar, Çağdaş; Turak, Fatma; Bakırdere, Sezgin

2018-05-01

In this study, dispersive liquid-liquid microextraction was systematically optimized for the preconcentration of nickel after forming a complex with diphenylcarbazone. The measurement output of the flame atomic absorption spectrometer was further enhanced by fitting a custom-cut slotted quartz tube to the flame burner head. The extraction method increased the amount of nickel reaching the flame and the slotted quartz tube increased the residence time of nickel atoms in the flame to record higher absorbance. Two methods combined to give about 90 fold enhancement in sensitivity over the conventional flame atomic absorption spectrometry. The optimized method was applicable over a wide linear concentration range, and it gave a detection limit of 2.1 µg L -1 . Low relative standard deviations at the lowest concentration in the linear calibration plot indicated high precision for both extraction process and instrumental measurements. A coal fly ash standard reference material (SRM 1633c) was used to determine the accuracy of the method, and experimented results were compatible with the certified value. Spiked recovery tests were also used to validate the applicability of the method.

Comparison of salivary collection and processing methods for quantitative HHV-8 detection.

PubMed

Speicher, D J; Johnson, N W

2014-10-01

Saliva is a proved diagnostic fluid for the qualitative detection of infectious agents, but the accuracy of viral load determinations is unknown. Stabilising fluids impede nucleic acid degradation, compared with collection onto ice and then freezing, and we have shown that the DNA Genotek P-021 prototype kit (P-021) can produce high-quality DNA after 14 months of storage at room temperature. Here we evaluate the quantitative capability of 10 collection/processing methods. Unstimulated whole mouth fluid was spiked with a mixture of HHV-8 cloned constructs, 10-fold serial dilutions were produced, and samples were extracted and then examined with quantitative PCR (qPCR). Calibration curves were compared by linear regression and qPCR dynamics. All methods extracted with commercial spin columns produced linear calibration curves with large dynamic range and gave accurate viral loads. Ethanol precipitation of the P-021 does not produce a linear standard curve, and virus is lost in the cell pellet. DNA extractions from the P-021 using commercial spin columns produced linear standard curves with wide dynamic range and excellent limit of detection. When extracted with spin columns, the P-021 enables accurate viral loads down to 23 copies μl(-1) DNA. The quantitative and long-term storage capability of this system makes it ideal for study of salivary DNA viruses in resource-poor settings. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Determination of triazine herbicides in seaweeds: development of a sample preparation method based on Matrix Solid Phase Dispersion and Solid Phase Extraction Clean-up.

PubMed

Rodríguez-González, N; González-Castro, M J; Beceiro-González, E; Muniategui-Lorenzo, S; Prada-Rodríguez, D

2014-04-01

A method using dual process columns of Matrix Solid Phase Dispersion (MSPD) and Solid Phase Extraction (SPE) has been developed for extracting and cleaning-up of nine triazine herbicides (ametryn, atrazine, cyanazine, prometryn, propazine, simazine, simetryn, terbuthylazine and terbutryn) in seaweed samples. Under optimized conditions, samples were blended with 2g of octasilyl-derivatized silica (C8) and transferred into an SPE cartridge containing ENVI-Carb II/PSA (0.5/0.5 g) as a clean up co-sorbent. Then the dispersed sample was washed with 10 mL of n-hexane and triazines were eluted with 20 mL ethyl acetate and 5 mL acetonitrile. Finally the extract was concentrated to dryness, re-constituted with 1 mL methanol:water (1:1) and injected into the HPLC-DAD system. The linearity of the calibration curves was excellent in matrix matched standards, and yielded the coefficients of determination>0.995 for all the target analytes. The recoveries ranged from 75% to 100% with relative standard deviations lower than 7%. The achieved LOQs (<10 µg kg(-1)) for all triazines under study permits to ensure proper determination at the maximum allowed residue levels set in the European Union Legislation. Samples of three seaweeds were subjected to the procedure proving the suitability of MSPD method for the analysis of triazines in different seaweeds samples. Copyright © 2014 Elsevier B.V. All rights reserved.

Determination of rhynchophylline and hirsutine in rat plasma by UPLC-MS/MS after oral administration of Uncaria rhynchophylla extract.

PubMed

Wu, Yu-Tse; Lin, Lie-Chwen; Tsai, Tung-Hu

2014-03-01

An ultra-performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) method was developed and validated to concurrently determine rhynchophylline and hirsutine in rat plasma. The sample preparation of rat plasma was achieved by alkalization and liquid-liquid extraction. The mass transition of precursor ion → product ion pairs were monitored at m/z 385.2 → 160.0 for rhynchophylline, m/z 369.3 → 144.0 for hirsutine and m/z 414.0 → 220.0 for noscapine (internal standard). This method revealed linear relationships from 2.5 to 50 ng/mL (r(2)  > 0.997) for rhynchophylline and from 2.5 to 50 ng/mL (r(2)  > 0.998) for hirsutine. The limit of quantification values for rhynchophylline and hirsutine in rat plasma were both 2.5 ng/mL. Intra-day and inter-day precisions were within 10.6% and 12.5%, respectively, for rhynchophylline and hirsutine, and the accuracy (bias) was <10%. Liquid-liquid extraction of rat plasma samples resulted in insignificant matrix effect, and the extraction recoveries were >83.6% for rhynchophylline, 73.4% for hirsutine and 90.7% for the internal standard. This method was applied successfully to a pharmacokinetic study of rhynchophylline and hirsutine in rats after oral administration. Copyright © 2013 John Wiley & Sons, Ltd.

Characterization of ambient and extracted PM2.5 collected on filters for toxicology applications

PubMed Central

Roper, Courtney; Chubb, Lauren G.; Cambal, Leah; Tunno, Brett; Clougherty, Jane E.; Mischler, Steven E.

2016-01-01

Research on the health effects of fine particulate matter (PM2.5) frequently disregards the differences in particle composition between that measured on an ambient filter versus that measured in the corresponding extraction solution used for toxicological testing. This study presents a novel method for characterizing the differences, in metallic and organic species, between the ambient samples and the corresponding extracted solutions through characterization of extracted PM2.5 suspended on filters. Removal efficiency was found to be 98.0 ± 1.4% when measured using pre- and post-removal filter weights, however, this efficiency was significantly reduced to 80.2 ± 0.8% when measured based on particle mass in the extraction solution. Furthermore, only 47.2 ± 22.3% of metals and 24.8 ± 14.5% of organics measured on the ambient filter were found in the extraction solution. Individual metallic and organic components were extracted with varying efficiency, with many organics being lost entirely during extraction. Finally, extraction efficiencies of specific PM2.5 components were inversely correlated with total mass. This study details a method to assess compositional alterations resulting from extraction of PM2.5 from filters, emphasizing the need for standardized procedures that maintain compositional integrity of ambient samples for use in toxicology studies of PM2.5. PMID:26446919

Quantitative analysis of phosphoric acid esters in aqueous samples by isotope dilution stir-bar sorptive extraction combined with direct analysis in real time (DART)-Orbitrap mass spectrometry.

PubMed

Bridoux, Maxime C; Malandain, Hélène; Leprince, Françoise; Progent, Frédéric; Machuron-Mandard, Xavier

2015-04-15

A novel hyphenated technique, namely the combination of stir bar sorptive extraction (SBSE) with isotope dilution direct analysis in real time (DART) Orbitrap™ mass spectrometry (OT-MS) is presented for the extraction of phosphoric acid alkyl esters (tri- (TnBP), di- (HDBP), and mono-butyl phosphate (H2MBP)) from aqueous samples. First, SBSE of phosphate esters was performed using a Twister™ coated with 24 μL of polydimethylsiloxane (PDMS) as the extracting phase. SBSE was optimized for extraction pH, phase ratio (PDMS volume/aqueous phase volume), stirring speed, extraction time and temperature. Then, coupling of SBSE to DART/Orbitrap-MS was achieved by placing the Twister™ in the middle of an open-ended glass tube between the DART and the Orbitrap™. The DART mass spectrometric response of phosphate esters was probed using commercially available and synthesized alkyl phosphate ester standards. The positive ion full scan spectra of alkyl phosphate triesters (TnBP) was characterized by the product of self-protonation [M+H](+) and, during collision-induced dissociation (CID), the major fragmentation ions corresponded to consecutive loss of alkyl chains. Negative ionization gave abundant [M-H](-) ions for both HDnBP and H2MnBP. Twisters™ coated with PDMS successfully extracted phosphate acid esters (tri-, di- and mono-esters) granted that the analytes are present in the aqueous solution in the neutral form. SBSE/DART/Orbitrap-MS results show a good linearity between the concentrations and relative peak areas for the analytes in the concentration range studied (0.1-750 ng mL(-1)). Reproducibility of this SBSE/DART/Orbitrap-MS method was evaluated in terms of %RSD by extracting a sample of water fortified with the analytes. The %RSDs for TnBP, HDnBP and H2MnBP were 4, 3 and 3% (n=5) using the respective perdeuterated internal standards. Matrix effects were investigated by matrix matched calibration standards using underground water samples (UWS) and river water samples (RWS). Matrix effects were effectively compensated by the addition of the perdeuterated internal standards. The application of this new SBSE/DART/Orbitrap-MS method should be very valuable for on-site sampling/monitoring, limiting the transport of large volumes of water samples from the sampling site to the laboratory. Copyright © 2015 Elsevier B.V. All rights reserved.

A quantitative LC-MS/MS method for simultaneous determination of cocaine and its metabolites in whole blood

PubMed Central

Chen, Xiabin; Zheng, Xirong; Ding, Kai; Zhou, Ziyuan; Zhan, Chang-Guo; Zheng, Fang

2016-01-01

As new metabolic pathways of cocaine were recently identified, a high performance liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed to simultaneously determine cocaine and nine cocaine-related metabolites in whole blood samples. One-step solid phase extraction was used to extract all of the ten compounds and corresponding internal standards from blood samples. All compounds and internal standards extracted were separated on an Atlantis T3 (100Å, 3 µm, 2.1 mm × 150 mm I.D) column and detected in positive ion and high sensitivity mode with multiple reaction monitoring. This method was validated for its sensitivity, linearity, specificity, accuracy, precision, recovery, and stability. All of the ten compounds were quantifiable ranging from the lower limit of quantification (LLOQs) of ~10 nM (1.9–3.2 ng/ml) to ~1000 nM (190–320 ng/ml) without any interfering substance. Accuracy and precision were determined, and both of them were within the acceptance criteria of the United States (US) Food and Drug Administration (FDA) and European Medicines Agency (EMA) guidelines. The recovery was above 66.7% for all compounds. Stability tests demonstrated the stability of compounds under different storage conditions in whole blood samples. The method was successfully applied to a pharmacokinetic study with co-administration of cocaine and alcohol in rats. PMID:27923200

Extract-filter-shoot liquid chromatography with mass spectrometry for the analysis of vitamin D2 in a powdered supplement capsule and standard reference material 3280.

PubMed

Byrdwell, William Craig

2014-08-01

An "extract-filter-shoot" method for the analysis of vitamin D2, ergocalciferol, in a dry powdered dietary supplement capsule containing rice flour excipient and in a National Institute of Standards and Technology standard reference material 3280 is reported. Quantification of vitamin D2 was done by atmospheric pressure chemical ionization mass spectrometry using selected ion monitoring, two transitions of selected reaction monitoring, and extracted ion chromatograms from full scans. UV detection was used for the quantification of Vitamin D2 in the dry powder capsule, whereas interfering species rendered UV detection unreliable for standard reference material 3280. Average values for standard reference material 3280 ranged from 8.27 ± 0.58 to 8.33 ± 0.57 μg/g using internal standard calibration and response factor approaches, compared to the previous National Institute of Standards and Technology internal value for vitamin D2 of 8.78 ± 0.11 μg/g, and the recently updated reference value of 8.6 ± 2.6 μg/g. The powdered supplement capsule was found to contain 28.19 ± 0.35 to 28.67 ± 0.90 μg/capsule for a capsule labeled to contain 25.00 μg. The triacylglycerol composition of the rice flour excipient in the powdered supplement capsule determined by atmospheric pressure chemical ionization mass spectrometry is also reported. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Multicomponent UV Analysis of ["alpha"]- and ["beta"]-Acids in Hops

ERIC Educational Resources Information Center

Egts, Haley; Durben, Dan J.; Dixson, John A.; Zehfus, Micheal H.

2012-01-01

A method is presented for the determination of ["alpha"]- and ["beta"]-acids (humulones and lupulones) in a hops sample using a multicomponent UV spectroscopic analysis of a methanolic hop extract. When compared with standard methods, this lab can be considered "greener" because it uses smaller volumes of safer solvents (methanol instead of…

Characterization analysis for leaves of Leucaena leucocephala by using phytochemical screening assay

NASA Astrophysics Data System (ADS)

Zarina, Z.; Ghazali, C. M. R.; Sam, S. T.

2017-09-01

Leucaena Leucocephala (Lam.) de Wit (Petai Belalang) is a medium plant which belong in group of tropical breed that can survived in hot, dried and warm environment. In Malaysia, the plant is available abundantly. As there are still no commercial used, and no serious intention in finding the benefits of L. Leucocephala, this work come out with the idea to analyze the antioxidants contains in leaves of the plant by undergoes different extraction and chemical testing method. The phytochemical screening assay involved in this study are antioxidant activity by using free radical diphenylpicrylhydrazyl (DPPH) method, total phenolic content by using Folin-Ciocalteu method, total flavonoid content by using colorimetric assay with ascorbic acid and quercetin were used as reference standards while for phosphorus analysis, a molybdenum blue method or also known as ascorbic acid method was used. For antioxidant activity by using free radical diphenylpicrylhydrazyl (DPPH) method, higher concentration was recorded by extraction using methanol (dried sample) which is 8247.0 mg/L, for total phenolic content higher concentration was recorded by extraction using deionized water (dried sample) which is 4276.0 mg/L, for total flavonoid content by using colorimetric assay higher concentration was recorded by extraction using methanol (dried sample) which is 4439.0 mg/L, and for for phosphorus analysis higher concentration was recorded by extraction using methanol (dried sample) which is 71.057 mg/L.

Characterization analysis for leaves of Leucaena Leucocephala by using phytochemical screening assay

NASA Astrophysics Data System (ADS)

Zarina, Z.; Ghazali, C. M. R.; Sam, S. T.

2017-09-01

Leucaena Leucocephala (Lam.) de Wit (Petai Belalang) is a medium plant which belong in group of tropical breed that can survived in hot, dried and warm environment. In Malaysia, the plant is available abundantly. As there are still no commercial used, and no serious intention in finding the benefits of L. Leucocephala, this work come out with the idea to analyze the antioxidants contains in leaves of the plant by undergoes different extraction and chemical testing method. The phytochemical screening assay involved in this study are antioxidant activity by using free radical diphenylpicrylhydrazyl (DPPH) method, total phenolic content by using Folin-Ciocalteu method, total flavonoid content by using colorimetric assay with ascorbic acid and quercetin were used as reference standards while for phosphorus analysis, a molybdenum blue method or also known as ascorbic acid method was used. For antioxidant activity by using free radical diphenylpicrylhydrazyl (DPPH) method, higher concentration was recorded by extraction using methanol (dried sample) which is 8247.0 mg/L, for total phenolic content higher concentration was recorded by extraction using deionized water (dried sample) which is 4276.0 mg/L, for total flavonoid content by using colorimetric assay higher concentration was recorded by extraction using methanol (dried sample) which is 4439.0 mg/L, and for for phosphorus analysis higher concentration was recorded by extraction using methanol (dried sample) which is 71.057 mg/L.

Analysis of Trace Quaternary Ammonium Compounds (QACs) in Vegetables Using Ultrasonic-Assisted Extraction and Gas Chromatography-Mass Spectrometry.

PubMed

Xiang, Lei; Wang, Xiong-Ke; Li, Yan-Wen; Huang, Xian-Pei; Wu, Xiao-Lian; Zhao, Hai-Ming; Li, Hui; Cai, Quan-Ying; Mo, Ce-Hui

2015-08-05

A reliable, sensitive, and cost-effective method was developed for determining three quaternary ammonium compounds (QACs) including dodecyltrimethylammonium chloride, cetyltrimethylammonium chloride, and didodecyldimethylammonium chloride in various vegetables using ultrasonic-assisted extraction and gas chromatography-mass spectrometry. The variety and acidity of extraction solvents, extraction times, and cleanup efficiency of sorbents were estimated to obtain an optimized procedure for extraction of the QACs in nine vegetable matrices. Excellent linearities (R(2) > 0.992) were obtained for the analytes in the nine matrices. The limits of detection and quantitation were 0.7-6.0 and 2.3-20.0 μg/kg (dry weight, dw) in various matrices, respectively. The recoveries in the nine matrices ranged from 70.5% to 108.0% with relative standard deviations below 18.0%. The developed method was applied to determine the QACs in 27 vegetable samples collected from Guangzhou in southern China, showing very high detection frequency with a concentration of 23-180 μg/kg (dw).

Single-laboratory validation of the microplate receptor binding assay for paralytic shellfish toxins in shellfish.

PubMed

Van Dolah, Frances M; Leighfield, Tod A; Doucette, Gregory J; Bean, Laurie; Niedzwiadek, Barbara; Rawn, Dorothea F K

2009-01-01

A single-laboratory validation (SLV) study was conducted for the microplate receptor binding assay (RBA) for paralytic shellfish poisoning (PSP) toxins in shellfish. The basis of the assay is the competition between [3H]saxitoxin (STX) and STX in a standard or sample for binding to the voltage dependent sodium channel. A calibration curve is generated by the addition of 0.01-1000 nM STX, which results in the concentration dependent decrease in [3H]STX-receptor complexes formed and serves to quantify STX in unknown samples. This study established the LOQ, linearity, recovery, accuracy, and precision of the assay for determining PSP toxicity in shellfish extracts, as performed by a single analyst on multiple days. The standard curve obtained on 5 independent days resulted in a half-maximal inhibition (IC50) of 2.3 nM STX +/- 0.3 (RSD = 10.8%) with a slope of 0.96 +/- 0.06 (RSD = 6.3%) and a dynamic range of 1.2-10.0 nM. The LOQ was 5.3 microg STX equivalents/100 g shellfish. Linearity, established by quantification of three levels of purified STX (1.5, 3, and 6 nM), yielded an r2 of 0.97. Recovery from mussels spiked with three levels (40, 80, and 120 microg STX/100 g) averaged 121%. Repeatability (RSD(r)), determined on six naturally contaminated shellfish samples on 5 independent days, was 17.7%. A method comparison with the AOAC mouse bioassay yielded r2 = 0.98 (slope = 1.29) in the SLV study. The effects of the extraction method on RBA-based toxicity values were assessed on shellfish extracted for PSP toxins using the AOAC mouse bioassay method (0.1 M HCI) compared to that for the precolumn oxidation HPLC method (0.1% acetic acid). The two extraction methods showed linear correlation (r2 = 0.99), with the HCl extraction method yielding slightly higher toxicity values (slope = 1.23). A similar relationship was observed between HPLC quantification of the HCI- and acetic acid-extracted samples (r2 = 0.98, slope 1.19). The RBA also had excellent linear correlation with HPLC analyses (r2 = 0.98 for HCl, r2 = 0.99 for acetic acid), but gave somewhat higher values than HPLC using either extraction method (slope = 1.39 for HCl extracts, slope = 1.32 for acetic acid). Overall, the excellent linear correlations with the both mouse bioassay and HPLC method and sufficient interassay repeatability suggest that the RBA can be effective as a high throughput screen for estimating PSP toxicity in shellfish.

Selection of Suitable DNA Extraction Methods for Genetically Modified Maize 3272, and Development and Evaluation of an Event-Specific Quantitative PCR Method for 3272.

PubMed

Takabatake, Reona; Masubuchi, Tomoko; Futo, Satoshi; Minegishi, Yasutaka; Noguchi, Akio; Kondo, Kazunari; Teshima, Reiko; Kurashima, Takeyo; Mano, Junichi; Kitta, Kazumi

2016-01-01

A novel real-time PCR-based analytical method was developed for the event-specific quantification of a genetically modified (GM) maize, 3272. We first attempted to obtain genome DNA from this maize using a DNeasy Plant Maxi kit and a DNeasy Plant Mini kit, which have been widely utilized in our previous studies, but DNA extraction yields from 3272 were markedly lower than those from non-GM maize seeds. However, lowering of DNA extraction yields was not observed with GM quicker or Genomic-tip 20/G. We chose GM quicker for evaluation of the quantitative method. We prepared a standard plasmid for 3272 quantification. The conversion factor (Cf), which is required to calculate the amount of a genetically modified organism (GMO), was experimentally determined for two real-time PCR instruments, the Applied Biosystems 7900HT (the ABI 7900) and the Applied Biosystems 7500 (the ABI7500). The determined Cf values were 0.60 and 0.59 for the ABI 7900 and the ABI 7500, respectively. To evaluate the developed method, a blind test was conducted as part of an interlaboratory study. The trueness and precision were evaluated as the bias and reproducibility of the relative standard deviation (RSDr). The determined values were similar to those in our previous validation studies. The limit of quantitation for the method was estimated to be 0.5% or less, and we concluded that the developed method would be suitable and practical for detection and quantification of 3272.

Carboxylated multiwalled carbon nanotubes/polydimethylsiloxane, a new coating for 96-blade solid-phase microextraction for determination of phenolic compounds in water.

PubMed

Kueseng, Pamornrat; Pawliszyn, Janusz

2013-11-22

A new thin-film, carboxylated multiwalled carbon nanotubes/polydimethylsiloxane (MWCNTs-COOH/PDMS) coating was developed for 96-blade solid-phase microextraction (SPME) system followed by high performance liquid chromatography with ultraviolet detection (HPLC-UV). The method provided good extraction efficiency (64-90%) for three spiked levels, with relative standard deviations (RSD)≤6%, and detection limits between 1 and 2 μg/L for three phenolic compounds. The MWCNTs-COOH/PDMS 96-blade SPME system presents advantages over traditional methods due to its simplicity of use, easy coating preparation, low cost and high sample throughput (2.1 min per sample). The developed coating is reusable for a minimum of 110 extractions with good extraction efficiency. The coating provided higher extraction efficiency (3-8 times greater) than pure PDMS coatings. Copyright © 2013 Elsevier B.V. All rights reserved.

Field Application of a Rapid Spectrophotometric Method for Determination of Persulfate in Soil

PubMed Central

Cunningham, Colin J.; Pitschi, Vanessa; Anderson, Peter; Barry, D. A.; Patterson, Colin; Peshkur, Tanya A.

2013-01-01

Remediation of hydrocarbon contaminated soils can be performed both in situ and ex situ using chemical oxidants such as sodium persulfate. Standard methods for quantifying persulfate require either centrifugation or prolonged settling times. An optimized soil extraction procedure was developed for persulfate involving simple water extraction using a modified disposable syringe. This allows considerable saving of time and removes the need for centrifugation. The extraction time was reduced to only 5 min compared to 15 min for the standard approach. A comparison of the two approaches demonstrated that each provides comparable results. Comparisons were made using high (93 g kg−1 soil) and low (9.3 g kg−1 soil) additions of sodium persulfate to a petroleum hydrocarbon-contaminated soil, as well as sand spiked with diesel. Recoveries of 95±1% and 96±10% were observed with the higher application rate in the contaminated soil and spiked sand, respectively. Corresponding recoveries of 86±5% and 117±19% were measured for the lower application rate. Results were obtained in only 25 min and the method is well suited to batch analyses. In addition, it is suitable for application in a small field laboratory or even a mobile, vehicle-based system, as it requires minimal equipment and reagents. PMID:23776446

1H NMR determination of beta-N-methylamino-L-alanine (L-BMAA) in environmental and biological samples.

PubMed

Moura, Sidnei; Ultramari, Mariah de Almeida; de Paula, Daniela Mendes Louzada; Yonamine, Mauricio; Pinto, Ernani

2009-04-01

A nuclear magnetic resonance (1H NMR) method for the determination of beta-N-methylamino-L-alanine (L-BMAA) in environmental aqueous samples was developed and validated. L-BMAA is a neurotoxic modified amino acid that can be produced by cyanobacteria in aqueous environments. This toxin was extracted from samples by means of solid-phase extraction (SPE) and identified and quantified by 1H NMR without further derivatization steps. The lower limit of quantification (LLOQ) was 5 microg/mL. Good inter and intra-assay precision was also observed (relative standard deviation <8.5%) with the use of 4-nitro-DL-phenylalanine as an internal standard (IS). This method of 1H NMR analysis is not time consuming and can be readily utilized to monitor L-BMAA and confirm its presence in environmental and biological samples.

Extraction and Determination of Cyproheptadine in Human Urine by DLLME-HPLC Method

PubMed Central

Maham, Mehdi; Kiarostami, Vahid; Waqif-Husain, Syed; Abroomand-Azar, Parviz; Tehrani, Mohammad Saber; Khoeini Sharifabadi, Malihe; Afrouzi, Hossein; Shapouri, MahmoudReza; Karami-Osboo, Rouhollah

2013-01-01

Novel dispersive liquid-liquid microextraction (DLLME), coupled with high performance liquid chromatography with photodiode array detection (HPLC-DAD) has been applied for the extraction and determination of cyproheptadine (CPH), an antihistamine, in human urine samples. In this method, 0.6 mL of acetonitrile (disperser solvent) containing 30 μL of carbon tetrachloride (extraction solvent) was rapidly injected by a syringe into 5 mL urine sample. After centrifugation, the sedimented phase containing enriched analyte was dissolved in acetonitrile and an aliquot of this solution injected into the HPLC system for analysis. Development of DLLME procedure includes optimization of some important parameters such as kind and volume of extraction and disperser solvent, pH and salt addition. The proposed method has good linearity in the range of 0.02-4.5 μg mL-1 and low detection limit (13.1 ng mL-1). The repeatability of the method, expressed as relative standard deviation was 4.9% (n = 3). This method has also been applied to the analysis of real urine samples with satisfactory relative recoveries in the range of 91.6-101.0%. PMID:24250605

Gold in natural water: A method of determination by solvent extraction and electrothermal atomization

USGS Publications Warehouse

McHugh, J.B.

1984-01-01

A method has been developed using electrothermal atomization to effectively determine the amount of gold in natural water within the nanogram range. The method has four basic steps: (1) evaporating a 1-L sample; (2) putting it in hydrobromic acid-bromine solution; (3) extracting the sample with methyl-isobutyl-ketone; and (4) determining the amount of gold using an atomic absorption spectrophotometer. The limit of detection is 0.001 ??g gold per liter. Results from three studies indicate, respectively, that the method is precise, effective, and free of interference. Specifically, a precision study indicates that the method has a relative standard deviation of 16-18%; a recovery study indicates that the method recovers gold at an average of 93%; and an interference study indicates that the interference effects are eliminated with solvent extraction and background correction techniques. Application of the method to water samples collected from 41 sites throughout the Western United States and Alaska shows a gold concentration range of < 0.001 to 0.036 ??g gold per liter, with an average of 0.005 ??g/L. ?? 1984.

Simultaneous identification and quantification of bisphenol A and 12 bisphenol analogues in environmental samples using precolumn derivatization and ultra high performance liquid chromatography with tandem mass spectrometry.

PubMed

Wang, Zhonghe; Yu, Jing; Yao, Jiaxi; Wu, Linlin; Xiao, Hang; Wang, Jun; Gao, Rong

2018-02-10

A method for the identification and quantification of bisphenol A and 12 bisphenol analogues in river water and sediment samples combining liquid-liquid extraction, precolumn derivatization, and ultra high-performance liquid chromatography coupled with tandem mass spectrometry was developed and validated. Analytes were extracted from the river water sample using a liquid-liquid extraction method. Dansyl chloride was selected as a derivatization reagent. Derivatization reaction conditions affecting production of the dansyl derivatives were tested and optimized. All the derivatized target compounds were well separated and eluted in 10 min. Dansyl chloride labeled compounds were analyzed using a high-resolution mass spectrometer with electrospray ionization in the positive mode, and the results were confirmed and quantified in the parallel reaction monitoring mode. The method validation results showed a satisfactory level of sensitivity. Linearity was assessed using matrix-matched standard calibration, and good correlation coefficients were obtained. The limits of quantification for the analytes ranged from 0.005 to 0.02 ng/mL in river water and from 0.15 to 0.80 ng/g in sediment. Good reproducibility of the method in terms of intra- and interday precision was achieved, yielding relative standard deviations of less than 10.1 and 11.6%, respectively. Finally, this method was successfully applied to the analysis of real samples. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of tiropramide in human plasma by liquid chromatography-tandem mass spectrometry.

PubMed

Lee, Hye Won; Ji, Hye Young; Kim, Hee Hyun; Cho, Hea-Young; Lee, Yong-Bok; Lee, Hye Suk

2003-11-05

A rapid, sensitive and selective liquid chromatography-tandem mass spectrometric (LC/MS/MS) method for the determination of tiropramide in human plasma was developed. Tiropramide and internal standard, cisapride were extracted from human plasma by liquid-liquid extraction and analyzed on a Luna C8 column with the mobile phase of acetonitrile-ammonium formate (10mM, pH 4.5) (50:50, v/v). The analytes was detected using an electrospray ionization tandem mass spectrometry in the multiple-reaction-monitoring mode. The standard curve was linear (r=0.998) over the concentration range of 2.0-200 ng/ml. The intra- and inter-assay coefficients of variation ranged from 2.8 to 7.8 and 6.7 to 8.9%, respectively. The recoveries of tiropramide ranged from 50.2 to 53.1%, with that of cisapride (internal standard) being 60.9+/-5.3%. The lower limit of quantification for tiropramide was 2.0 ng/ml using 100 microl plasma sample. This method was applied to the pharmacokinetic study of tiropramide in human.

Performance of digital RGB reflectance color extraction for plaque lesion

NASA Astrophysics Data System (ADS)

Hashim, Hadzli; Taib, Mohd Nasir; Jailani, Rozita; Sulaiman, Saadiah; Baba, Roshidah

2005-01-01

Several clinical psoriasis lesion groups are been studied for digital RGB color features extraction. Previous works have used samples size that included all the outliers lying beyond the standard deviation factors from the peak histograms. This paper described the statistical performances of the RGB model with and without removing these outliers. Plaque lesion is experimented with other types of psoriasis. The statistical tests are compared with respect to three samples size; the original 90 samples, the first size reduction by removing outliers from 2 standard deviation distances (2SD) and the second size reduction by removing outliers from 1 standard deviation distance (1SD). Quantification of data images through the normal/direct and differential of the conventional reflectance method is considered. Results performances are concluded by observing the error plots with 95% confidence interval and findings of the inference T-tests applied. The statistical tests outcomes have shown that B component for conventional differential method can be used to distinctively classify plaque from the other psoriasis groups in consistent with the error plots finding with an improvement in p-value greater than 0.5.

HMMBinder: DNA-Binding Protein Prediction Using HMM Profile Based Features.

PubMed

Zaman, Rianon; Chowdhury, Shahana Yasmin; Rashid, Mahmood A; Sharma, Alok; Dehzangi, Abdollah; Shatabda, Swakkhar

2017-01-01

DNA-binding proteins often play important role in various processes within the cell. Over the last decade, a wide range of classification algorithms and feature extraction techniques have been used to solve this problem. In this paper, we propose a novel DNA-binding protein prediction method called HMMBinder. HMMBinder uses monogram and bigram features extracted from the HMM profiles of the protein sequences. To the best of our knowledge, this is the first application of HMM profile based features for the DNA-binding protein prediction problem. We applied Support Vector Machines (SVM) as a classification technique in HMMBinder. Our method was tested on standard benchmark datasets. We experimentally show that our method outperforms the state-of-the-art methods found in the literature.

Determination of atmospheric organosulfates using HILIC chromatography with MS detection

NASA Astrophysics Data System (ADS)

Hettiyadura, A. P. S.; Stone, E. A.; Kundu, S.; Baker, Z.; Geddes, E.; Richards, K.; Humphry, T.

2015-06-01

Measurements of organosulfates in ambient aerosols provide insight to the extent of secondary organic aerosol (SOA) formation from mixtures of biogenic gases and anthropogenic pollutants. Organosulfates have, however, proved analytically challenging to quantify, due to lack of authentic standards and the complex sample matrix in which organosulfates are observed. This study presents a sensitive and accurate new analytical method for the quantification of organosulfates based upon ultra-performance liquid chromatography (UPLC) with negative electrospray ionization mass spectrometry (MS) with the aid of synthesized organosulfate standards. The separation is based upon hydrophilic interaction liquid chromatography (HILIC) with an amide stationary phase that provides excellent retention of carboxy-organosulfates and isoprene-derived organosulfates. The method is validated using six model compounds: methyl sulfate, ethyl sulfate, benzyl sulfate, hydroxyacetone sulfate, lactic acid sulfate and glycolic acid sulfate. A straightforward protocol for synthesis of highly pure organosulfate potassium salts for use as quantification standards is presented. This method is used to evaluate the efficiency and precision of two methods of ambient PM2.5 sample extraction. Spike recoveries averaged 98 ± 8% for extraction by ultra-sonication and 98 ± 10% for extraction by rotary shaking. Ultra-sonication was determined to be a better method due to its higher precision compared to rotary shaking. Analysis of ambient PM2.5 samples collected on 10-11 July 2013 in Centreville, AL, USA during the Southeast Atmosphere Study (SAS) confirms the presence of hydroxyacetone sulfate in ambient aerosol for the first time. Lactic acid sulfate was the most abundant compound measured (9.6-19 ng m-3), followed by glycolic acid sulfate (8-14 ng m-3) and hydroxyacetone sulfate (2.7-5.8 ng m-3). Trace amounts of methyl sulfate were detected, while ethyl sulfate and benzyl sulfate were not. Application of this HILIC separation method to ambient aerosol samples further demonstrates its utility in resolving additional biogenic organosulfates.

Antimycobacterial activity assessment of three ethnobotanical plants against Mycobacterium Tuberculosis: An In Vitro study.

PubMed

Arjomandzadegan, Mohammad; Emami, Navid; Habibi, Ghasem; Farazi, Ali Asghar; Kahbazi, Manijeh; Sarmadian, Hossein; Jabbari, Mansooreh; Hosseini, Hossein; Ramezani, Mona

2016-12-01

Resistances to herbal medicines are still not defined and finding natural remedies against drug resistant Mycobacterium tuberculosis (MTB) has research priority. The antimycobacterial susceptibility method for herbal extracts is unclearly defined and there is no standard method for assessment of the materials against bacteria. In the present study, time kill of three medicinal plants was determined against MTB. The clinical isolate of MTB from a patient who harbored confirmed tuberculosis was used in the study. Aqueous extracts of Aloe vera leaves, mint, and Hypericum perforatum were prepared using reflux distillation. Disk diffusion methods were conducted in Petri dishes and McCartney bottles containing Löwenstein-Jensen medium to measure the sensitivity of plant extracts in serial concentrations of 0.25-8mg/mL. A pour plate method was performed by mixing 0.7mL of each concentration of extract in 5mL Löwenstein-Jensen medium followed by surface culturing of MTB fresh cells. The time kill method was conducted by bacterial suspension in equal amounts of the extract and viable evaluation in fresh culture at the beginning, and at 24-h, 48-h, 72-h, and 1-week intervals. All cultures were incubated at 37°C for 4weeks. Inoculum concentrations were considered as a variable. The zones of inhibition of A. vera, H. perforatum, and mint extracts in the disk diffusion method in McCartney bottles were 60mm, 41mm, and zero, respectively, but Petri dishes did not have repeatable results. In the pour plate method, an extract concentration up to 1mg/mL could inhibit cell growth. In mint extract, colony forming was four times more than the others at 0.5mg/mL. Time kill of 95% of cells occurred when exposed to extracts of A. vera and H. perforatum separately, but was 50% in 24 h and 20% in 10 min. The time kill for mint was 95% in 1week. The results give some scientific basis to the use of plant extracts for growth control of MTB cells. Clinical trials are recommended for assessment of the extract as complementary medicine, as well as for antisepsis. Copyright © 2016.

Graphene oxide-based dispersive solid-phase extraction combined with in situ derivatization and gas chromatography-mass spectrometry for the determination of acidic pharmaceuticals in water.

PubMed

Naing, Nyi Nyi; Li, Sam Fong Yau; Lee, Hian Kee

2015-12-24

A fast and low-cost sample preparation method of graphene based dispersive solid-phase extraction combined with gas chromatography-mass spectrometric (GC-MS) analysis, was developed. The procedure involves an initial extraction with water-immiscible organic solvent, followed by a rapid clean-up using amine functionalized reduced graphene oxide as sorbent. Simple and fast one-step in situ derivatization using trimethylphenylammonium hydroxide was subsequently applied on acidic pharmaceuticals serving as model analytes, ibuprofen, gemfibrozil, naproxen, ketoprofen and diclofenac, before GC-MS analysis. Extraction parameters affecting the derivatization and extraction efficiency such as volume of derivatization agent, effect of desorption solvent, effect of pH and effect of ionic strength were investigated. Under the optimum conditions, the method demonstrated good limits of detection ranging from 1 to 16ngL(-1), linearity (from 0.01 to 50 and 0.05 to 50μgL(-1), depending on the analytes) and satisfactory repeatability of extractions (relative standard deviations, below 13%, n=3). Copyright © 2015 Elsevier B.V. All rights reserved.

Ultrathin-shell boron nitride hollow spheres as sorbent for dispersive solid-phase extraction of polychlorinated biphenyls from environmental water samples.

PubMed

Fu, Meizhen; Xing, Hanzhu; Chen, Xiangfeng; Chen, Fan; Wu, Chi-Man Lawrence; Zhao, Rusong; Cheng, Chuange

2014-11-21

Boron nitride hollow spheres with ultrathin-shells were synthesized and used as sorbents for dispersive solid-phase extraction of aromatic pollutants at trace levels from environmental water samples. Polychlorinated biphenyls (PCBs) were selected as target compounds. Sample quantification and detection were performed by gas chromatography-tandem mass spectrometry. Extraction parameters influencing the extraction efficiency were optimized through response surface methodology using the Box-Behnken design. The proposed method achieved good linearity within the concentration range of 0.15-250 ng L(-1) PCBs, low limits of detection (0.04-0.09 ng L(-1), S/N=3:1), good repeatability of the extractions (relative standard deviation, <12%, n=6), and satisfactory recoveries between 84.9% and 101.0% under optimal conditions. Real environmental samples collected from rivers, local lakes, rain and spring waters were analyzed using the developed method. Results demonstrated that the hexagonal boron nitride-based material has significant potential as a sorbent for organic pollutant extraction from environmental water samples. Copyright © 2014 Elsevier B.V. All rights reserved.

Determination of sedative hypnotics in sewage sludge by pressurized liquid extraction with high-performance liquid chromatography and tandem mass spectrometry.

PubMed

Arbeláez, Paula; Granados, Judith; Borrull, Francesc; Marcé, Rosa Maria; Pocurull, Eva

2014-12-01

This paper describes a method for the determination of eight sedative hypnotics (benzodiazepines and barbiturates) in sewage sludge using pressurized liquid extraction and liquid chromatography with tandem mass spectrometry. Pressurized liquid extraction operating conditions were optimized and maximum recoveries were reached using methanol under the following operational conditions: 100ºC, 1500 psi, extraction time of 5 min, one extraction cycle, flush volume of 60% and purge time of 120 s. Pressurized liquid extraction recoveries were higher than 88% for all the compounds except for carbamazepine (55%). The repeatability and reproducibility between days, expressed as relative standard deviation (n = 5), were lower than 6 and 10%, respectively. The detection limits for all compounds were lower than 12.5 μg/kg of dry weight. The method was applied to determine benzodiazepines and barbiturates in sewage sludge from urban sewage treatment plants, and carbamazepine showed the highest concentration (7.9-18.9 μg/kg dry weight). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A novel quality by design approach for developing an HPLC method to analyze herbal extracts: A case study of sugar content analysis.

PubMed

Shao, Jingyuan; Cao, Wen; Qu, Haibin; Pan, Jianyang; Gong, Xingchu

2018-01-01

The aim of this study was to present a novel analytical quality by design (AQbD) approach for developing an HPLC method to analyze herbal extracts. In this approach, critical method attributes (CMAs) and critical method parameters (CMPs) of the analytical method were determined using the same data collected from screening experiments. The HPLC-ELSD method for separation and quantification of sugars in Codonopsis Radix extract (CRE) samples and Astragali Radix extract (ARE) samples was developed as an example method with a novel AQbD approach. Potential CMAs and potential CMPs were found with Analytical Target Profile. After the screening experiments, the retention time of the D-glucose peak of CRE samples, the signal-to-noise ratio of the D-glucose peak of CRE samples, and retention time of the sucrose peak in ARE samples were considered CMAs. The initial and final composition of the mobile phase, flow rate, and column temperature were found to be CMPs using a standard partial regression coefficient method. The probability-based design space was calculated using a Monte-Carlo simulation method and verified by experiments. The optimized method was validated to be accurate and precise, and then it was applied in the analysis of CRE and ARE samples. The present AQbD approach is efficient and suitable for analysis objects with complex compositions.

A series of strategies for solving the shortage of reference standards for multi-components determination of traditional Chinese medicine, Mahoniae Caulis as a case.

PubMed

Wang, Wenguang; Ma, Xiaoli; Guo, Xiaoyu; Zhao, Mingbo; Tu, Pengfei; Jiang, Yong

2015-09-18

In order to solve the bottleneck of reference standards shortage for comprehensive quality control of traditional Chinese medicines (TCMs), a series of strategies, including one single reference standard to determine multi-compounds (SSDMC), quantitative analysis by standardized reference extract (QASRE), and quantitative nuclear magnetic resonance spectroscopy (qNMR) were proposed, and Mahoniae Caulis was selected as an example to develop and validate these methods for simultaneous determination of four alkaloids, columbamine, jatrorrhizine, palmatine, and berberine. Comprehensive comparisons among these methods and with the conventional external standard method (ESM) were carried out. The relative expanded uncertainty of measurement was firstly used to compare their credibility. The results showed that all these three new developed methods can accurately accomplish the quantification by using only one purified reference standard, but each of them has its own advantages and disadvantages as well as the specific application scope, which were also discussed in detail in this paper. Copyright © 2015 Elsevier B.V. All rights reserved.

Total phenolic, total flavonoid content, and antioxidant capacity of the leaves of Meyna spinosa Roxb., an Indian medicinal plant.

PubMed

Sen, Saikat; De, Biplab; Devanna, N; Chakraborty, Raja

2013-03-01

The objective of the present study was to determine the total phenolic and total flavonoid contents, and to evaluate the antioxidant potential of different leaf extracts of Meyna spinosa Roxb. ex Link, a traditional medicinal plant of India. Free radical scavenging and antioxidant potential of the methanol, ethyl acetate, and petroleum ether extracts of Meyna spinosa leaves were investigated using several in vitro and ex vivo assays, including the 2, 2-diphenyl-picrylhydrazyl radical scavenging, superoxide anion scavenging, hydroxyl radical scavenging, nitric oxide radical scavenging, hydrogen peroxide scavenging activity, metal chelating assay, and reducing power ability method. Total antioxidant activity of the extracts was estimated by the ferric thiocyanate method. Inhibition assay of lipid peroxidation and oxidative hemolysis were also performed to confirm the protective effect of the extracts. Total phenolic and total flavonoid contents of the extracts were estimated using standard chemical assay procedures. Methanol extracts showed the highest polyphenolic content and possessed the better antioxidant activity than the other two extracts. Total phenolic and total flavonoid contents in the methanol extract were (90.08 ± 0.44) mg gallic acid equivalents/g and (58.50 ± 0.09) mg quercetin equivalents/g, respectively. The IC50 of the methanol extract in the DPPH(·), superoxide anion, hydroxyl radical, nitric oxide radical, hydrogen peroxide scavenging activity and metal chelating assays were (16.4 ± 0.41), (35.9 ± 0.19), (24.1 ± 0.33), (23.7 ± 0.09), (126.8 ± 2.92), and (117.2 ± 1.01) μg·mL(-1), respectively. The methanol extract showed potent reducing power ability, total antioxidant activity, and significantly inhibit lipid peroxidation and oxidative hemolysis which was similar to that of standards. The results indicated a direct correlation between the antioxidant activity and the polyphenolic content of the extracts, which may the foremost contributors to the antioxidant activity of the plant. The present study confirmed that the methanol extract of Meyna spinosa leaves is a potential source of natural antioxidants. Copyright © 2013 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

Standardized Cannabis sativa extract attenuates tau and stathmin gene expression in the melanoma cell line.

PubMed

Vaseghi, Golnaz; Taki, Mohamad Javad; Javanmard, Shaghayegh Haghjooy

2017-10-01

Metastasis is the main cause of death in patients with melanoma. Cannabis-based medicines are effective adjunctive drugs in cancer patients. Tau and Stathmin proteins are the key proteins in cancer metastasis. Here we have investigated the effect of a standardized Cannabis sativa extract on cell migration and Tau and Stathmin gene expression in the melanoma cell line. In the treatment group, melanoma (B1617) was treated 48 hr with various concentrations of standardized C. sativa extract. Cells with no treatment were considered as the control group, then study was followed by Quantitative RT-Real Time PCR assay. Relative gene expression was calculated by the ΔΔct method. Migration assay was used to evaluate cancer metastasis. Tau and stathmin gene expression was significantly decreased compared to the control group. Cell migration was also significantly reduced compared to controls. C. sativa decreased tau and stathmin gene expression and cancer metastasis. The results may have some clinical relevance for the use of cannabis-based medicines in patients with metastatic melanoma.

Determination of emamectin benzoate in medicated fish feed.

PubMed

Farer, L J; Hayes, J; Rosen, J; Knight, P

1999-01-01

A method was developed to quantitate emamectin benzoate in fish feed at levels between 5 and 15 ppm. The active ingredient is extracted from 20 g medicated feed into aqueous-methanolic solvent by overnight shaking. A solid-phase extraction procedure using a 2 g C18 cartridge is then used to concentrate the active residue and remove interfering matrix components. The extracted drug and internal standard are eluted from the cartridge, evaporated to dryness, and reconstituted in methanol. A control feed sample and fortified control working standard are simultaneously prepared. Remaining interferences and sample analysis are further separated on a gradient liquid chromatographic system. Recovery of emamectin benzoate from fortified feeds ranged from 97 to 100%, with a coefficient of variation (CV) of 1.2%. Determination of emamectin benzoate in medicated feeds resulted in CVs ranging from 2.3 to 4.2% and recoveries of 88 to 98% of label claim.