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Sample records for additional sample clean-up

  1. Glufosinate ammonium clean-up procedure from water samples using SPE

    NASA Astrophysics Data System (ADS)

    Tayeb M., A.; Ismail B., S.; Mardiana-Jansar, K.; Ta, Goh Choo; Agustar, Hani Kartini

    2015-09-01

    For the determination of glufosinate ammonium residue in soil and water samples, different solid phase extraction (SPE) sorbent efficiency was studied. Four different SPE sorbents i.e.: CROMABOND PS-H+, CROMABOND PS-OH-, ISOLUTE ENV+, Water Sep-Pak and OASIS HLB were used. Sample clean-up performance was evaluated using high performance liquid chromatography (Agilent 1220 infinity LC) with fluorescence detector. Detection of FMO-derivatives was done at λ ex = 260 nm and λ em= 310 nm. OASIS HLB column was the most suitable for the clean-up in view of the overall feasibility of the analysis.

  2. Determination of amphetamines in hair by integrating sample disruption, clean-up and solid phase derivatization.

    PubMed

    Argente-García, A; Moliner-Martínez, Y; Campíns-Falcó, P; Verdú-Andrés, J; Herráez-Hernández, R

    2016-05-20

    The utility of matrix solid phase dispersion (MSPD) for the direct analysis of amphetamines in hair samples has been evaluated, using liquid chromatography (LC) with fluorescence detection and precolumn derivatization. The proposed approach is based on the employment of MSPD for matrix disruption and clean-up, followed by the derivatization of the analytes onto the dispersant-sample blend. The fluorogenic reagent 9-fluorenylmethyl chloroformate (FMOC) has been used for derivatization. Different conditions for MSPD, analyte purification and solid phase derivatization have been tested, using amphetamine (AMP), methamphetamine (MET), ephedrine (EPE) and 3,4-methylenedioxymethamphetamine (MDMA) as model compounds. The results have been compared with those achieved by using ultrasound-assisted alkaline digestion and by MSPD combined with conventional solution derivatization. On the basis of the results obtained, a methodology is proposed for the analysis of amphetamines in hair which integrates sample disruption, clean-up and derivatization using a C18 phase. Improved sensitivity is achieved with respect to that obtained by the alkaline digestion or by the MSPD followed by solution derivatization methods. The method can be used for the quantification of the tested amphetamines within the 2.0-20.0ng/mg concentration interval, with limits of detection (LODs) of 0.25-0.75ng/mg. The methodology is very simple and rapid (the preparation of the sample takes less than 15min). PMID:27108048

  3. Determination of amphetamines in hair by integrating sample disruption, clean-up and solid phase derivatization.

    PubMed

    Argente-García, A; Moliner-Martínez, Y; Campíns-Falcó, P; Verdú-Andrés, J; Herráez-Hernández, R

    2016-05-20

    The utility of matrix solid phase dispersion (MSPD) for the direct analysis of amphetamines in hair samples has been evaluated, using liquid chromatography (LC) with fluorescence detection and precolumn derivatization. The proposed approach is based on the employment of MSPD for matrix disruption and clean-up, followed by the derivatization of the analytes onto the dispersant-sample blend. The fluorogenic reagent 9-fluorenylmethyl chloroformate (FMOC) has been used for derivatization. Different conditions for MSPD, analyte purification and solid phase derivatization have been tested, using amphetamine (AMP), methamphetamine (MET), ephedrine (EPE) and 3,4-methylenedioxymethamphetamine (MDMA) as model compounds. The results have been compared with those achieved by using ultrasound-assisted alkaline digestion and by MSPD combined with conventional solution derivatization. On the basis of the results obtained, a methodology is proposed for the analysis of amphetamines in hair which integrates sample disruption, clean-up and derivatization using a C18 phase. Improved sensitivity is achieved with respect to that obtained by the alkaline digestion or by the MSPD followed by solution derivatization methods. The method can be used for the quantification of the tested amphetamines within the 2.0-20.0ng/mg concentration interval, with limits of detection (LODs) of 0.25-0.75ng/mg. The methodology is very simple and rapid (the preparation of the sample takes less than 15min).

  4. A Membrane-Based Electro-Separation Method (MBES) for Sample Clean-Up and Norovirus Concentration.

    PubMed

    Kang, Wei; Cannon, Jennifer L

    2015-01-01

    Noroviruses are the leading cause of acute gastroenteritis and foodborne illnesses in the United States. Enhanced methods for detecting noroviruses in food matrices are needed as current methods are complex, labor intensive and insensitive, often resulting in inhibition of downstream molecular detection and inefficient recovery. Membrane-based electro-separation (MBES) is a technique to exchange charged particles through a size-specific dialysis membrane from one solution to another using electric current as the driving force. Norovirus has a net negative surface charge in a neutrally buffered environment, so when placed in an electric field, it moves towards the anode. It can then be separated from the cathodic compartment where the sample is placed and then collected in the anodic compartment for downstream detection. In this study, a MBES-based system was designed, developed and evaluated for concentrating and recovering murine norovirus (MNV-1) from phosphate buffer. As high as 30.8% MNV-1 migrated from the 3.5 ml sample chamber to the 1.5 ml collection chamber across a 1 μm separation membrane when 20 V was applied for 30 min using 20 mM sodium phosphate with 0.01% SDS (pH 7.5) as the electrolyte. In optimization of the method, weak applied voltage (20 V), moderate duration (30 min), and low ionic strength electrolytes with SDS addition were needed to increase virus movement efficacy. The electric field strength of the system was the key factor to enhance virus movement, which could only be improved by shortening the electrodes distance, instead of increasing system applied voltage because of virus stability. This study successfully demonstrated the norovirus mobility in an electric field and migration across a size-specific membrane barrier in sodium phosphate electrolyte. With further modification and validation in food matrixes, a novel, quick, and cost-effective sample clean-up technique might be developed to separate norovirus particles from food

  5. Extraction, clean-up and gas chromatography-mass spectrometry characterization of zilpaterol as feed additive in fattening cattle.

    PubMed

    Bocca, B; Di Mattia, M; Cartoni, C; Fiori, M; Felli, M; Neri, B; Brambilla, G

    2003-01-01

    Zilpaterol is an adrenergic drug currently licensed in Mexico and South Africa as a feed additive for cattle close to consignment. In this study an analytical method to detect zilpaterol in commercial feeds was set up. The influence of extraction solvent and matrix was evaluated. The drug as a trimethylsilyl derivative was characterized by GC-MS, on a quadrupole detector, in the electron impact mode. Acidic extraction, solid-phase extraction C(18) non-endcapped clean-up and mass characterization on ions m/z 308, 291, 405, 390 provided zilpaterol recoveries >75.3% and repeatability <3.3% in feeds spiked in the range 30.0-120.0 ng/g. The limits of detection and quantification were 7.5 and 25.0 ng/g, respectively. Such limits are well below the dose of 5.0-20.0 microgram/g proposed as effective.

  6. A Membrane-Based Electro-Separation Method (MBES) for Sample Clean-Up and Norovirus Concentration

    PubMed Central

    Kang, Wei; Cannon, Jennifer L.

    2015-01-01

    Noroviruses are the leading cause of acute gastroenteritis and foodborne illnesses in the United States. Enhanced methods for detecting noroviruses in food matrices are needed as current methods are complex, labor intensive and insensitive, often resulting in inhibition of downstream molecular detection and inefficient recovery. Membrane-based electro-separation (MBES) is a technique to exchange charged particles through a size-specific dialysis membrane from one solution to another using electric current as the driving force. Norovirus has a net negative surface charge in a neutrally buffered environment, so when placed in an electric field, it moves towards the anode. It can then be separated from the cathodic compartment where the sample is placed and then collected in the anodic compartment for downstream detection. In this study, a MBES-based system was designed, developed and evaluated for concentrating and recovering murine norovirus (MNV-1) from phosphate buffer. As high as 30.8% MNV-1 migrated from the 3.5 ml sample chamber to the 1.5 ml collection chamber across a 1 μm separation membrane when 20 V was applied for 30 min using 20 mM sodium phosphate with 0.01% SDS (pH 7.5) as the electrolyte. In optimization of the method, weak applied voltage (20 V), moderate duration (30 min), and low ionic strength electrolytes with SDS addition were needed to increase virus movement efficacy. The electric field strength of the system was the key factor to enhance virus movement, which could only be improved by shortening the electrodes distance, instead of increasing system applied voltage because of virus stability. This study successfully demonstrated the norovirus mobility in an electric field and migration across a size-specific membrane barrier in sodium phosphate electrolyte. With further modification and validation in food matrixes, a novel, quick, and cost-effective sample clean-up technique might be developed to separate norovirus particles from food

  7. Water compatible stir-bar devices imprinted with underivatised glyphosate for selective sample clean-up.

    PubMed

    Gomez-Caballero, Alberto; Diaz-Diaz, Goretti; Bengoetxea, Olatz; Quintela, Amaia; Unceta, Nora; Goicolea, M Aranzazu; Barrio, Ramón J

    2016-06-17

    This paper reports the development of stir bars with a new MIP based coating, for the selective sorptive extraction of the herbicide glyphosate (GLYP). Molecular imprinting of the polymer has directly been carried out employing underivatised GLYP as the template molecule. Due to the poor solubility of the target compound in organic solvents, the MIP methodology has been optimised for rebinding in aqueous media, being the synthesis and the rebinding steps carried out in water:methanol mixtures and pure aqueous media. The coating has been developed by radical polymerisation initiated by UV energy, using N-allylthiourea and 2-dimethyl aminoethyl methacrylate as functional monomers and ethylene glycol dimethacrylate as the cross-linker. Mechanical stability of the coating has been improved using 1,3-divinyltetramethyldisiloxane in the polymerisation mixture. Under the optimised conditions, the MIP has demonstrated excellent selectivity for the target compound in the presence of structural analogues, including its major metabolites. The applicability of the proposed method to real matrices has also been assessed using river water and soil samples. Registered mean recoveries ranged from 90.6 to 97.3% and RSD values were below 5% in all cases, what confirmed the suitability of the described methodology for the selective extraction and quantification of GLYP.

  8. Water compatible stir-bar devices imprinted with underivatised glyphosate for selective sample clean-up.

    PubMed

    Gomez-Caballero, Alberto; Diaz-Diaz, Goretti; Bengoetxea, Olatz; Quintela, Amaia; Unceta, Nora; Goicolea, M Aranzazu; Barrio, Ramón J

    2016-06-17

    This paper reports the development of stir bars with a new MIP based coating, for the selective sorptive extraction of the herbicide glyphosate (GLYP). Molecular imprinting of the polymer has directly been carried out employing underivatised GLYP as the template molecule. Due to the poor solubility of the target compound in organic solvents, the MIP methodology has been optimised for rebinding in aqueous media, being the synthesis and the rebinding steps carried out in water:methanol mixtures and pure aqueous media. The coating has been developed by radical polymerisation initiated by UV energy, using N-allylthiourea and 2-dimethyl aminoethyl methacrylate as functional monomers and ethylene glycol dimethacrylate as the cross-linker. Mechanical stability of the coating has been improved using 1,3-divinyltetramethyldisiloxane in the polymerisation mixture. Under the optimised conditions, the MIP has demonstrated excellent selectivity for the target compound in the presence of structural analogues, including its major metabolites. The applicability of the proposed method to real matrices has also been assessed using river water and soil samples. Registered mean recoveries ranged from 90.6 to 97.3% and RSD values were below 5% in all cases, what confirmed the suitability of the described methodology for the selective extraction and quantification of GLYP. PMID:27207580

  9. Efficient sample clean-up and online preconcentration for sensitive determination of melamine in milk samples by capillary electrophoresis with contactless conductivity detection.

    PubMed

    Ji, Yan-ling; Chen, Xiao-wei; Zhang, Zhu-bao; Li, Jing; Xie, Tian-yao

    2014-10-01

    Based on an efficient sample clean-up and field-amplified sample injection online preconcentration technique in capillary electrophoresis with contactless conductivity detection, a new analytical method for the sensitive determination of melamine in milk samples was established. In order to remove the complex matrix interference, which resulted in a serious problem during field-amplified sample injection, liquid-liquid extraction was utilized. As a result, liquid-liquid extraction provides excellent sample clean-up efficiency when ethyl acetate was used as organic extraction by adjusting the pH of the sample solution to 9.5. Both inorganic salts and biological macromolecules are effectively removed by liquid-liquid extraction. The sample clean-up procedure, capillary electrophoresis separation parameters and field-amplified sample injection conditions are discussed in detail. The capillary electrophoresis separation was achieved within 5 min under the following conditions: an uncoated fused-silica capillary, 12 mM HAc + 10 mM NaAc (pH = 4.6) as running buffer, separation voltage of +13 kV, electrokinetic injection of +12 kV × 10 s. Preliminary validation of the method performance with spiked melamine provided recoveries >90%, with limits of detection and quantification of 0.015 and 0.050 mg/kg, respectively. The relative standard deviations of intra- and inter-day were below 6%. This newly developed method is sensitive and cost effective, therefore, suitable for screening of melamine contamination in milk products.

  10. A LC/UV/Vis method for determination of cyanocobalamin in multivitamin dietary supplements with on-line sample clean-up

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A HPLC-UV method using a two-column strategy with a switching valve for on-line sample clean-up was developed for the determination of cyanocobalamin (CN-CBL-vitamin B12, in dietary supplements. The method uses two columns, an Agilent Zorbax C8 (150 mm x 4.6 mm, 5 um particle) reversed-phase column...

  11. Restricted access materials for sample clean-up in the analysis of trace levels of tetracyclines by liquid chromatography. Application to food and environmental analysis.

    PubMed

    Chico, J; Meca, S; Companyó, R; Prat, M D; Granados, M

    2008-02-15

    Restricted access materials (RAM) based on alkyl diol silica (ADS) porous particles were evaluated for the sample clean-up in tetracyclines analysis in milk and water samples by liquid chromatography. RAM with C(4), C(8) and C(18) bonded to the inner pore surfaces were tested, with C(8) providing the best performance. A switching column LC system which combines an ADS C(8) RAM column and an analytical C(18) column connected to a fluorimetric detector was used for tetracyclines analysis. The RAM clean-up removed large peaks that otherwise appeared in the initial time window of the chromatograms, attributed to proteins in milk samples and humic substances in water samples. Thus, quantification of analytes in real samples, especially of the most polar compounds such as oxytetracycline and tetracycline, was clearly improved.

  12. Development of sample clean up methods for the analysis of Mycobacterium tuberculosis methyl mycocerosate biomarkers in sputum extracts by gas chromatography–mass spectrometry

    PubMed Central

    Nicoara, Simona C.; Turner, Nicholas W.; Minnikin, David E.; Lee, Oona Y.-C.; O'Sullivan, Denise M.; McNerney, Ruth; Mutetwa, Reggie; Corbett, Liz E.; Morgan, Geraint H.

    2015-01-01

    A proof of principle gas chromatography–mass spectrometry method is presented, in combination with clean up assays, aiming to improve the analysis of methyl mycocerosate tuberculosis biomarkers from sputum. Methyl mycocerosates are generated from the transesterification of phthiocerol dimycocerosates (PDIMs), extracted in petroleum ether from sputum of tuberculosis suspect patients. When a high matrix background is present in the sputum extracts, the identification of the chromatographic peaks corresponding to the methyl derivatives of PDIMs analytes may be hindered by the closely eluting methyl ether of cholesterol, usually an abundant matrix constituent frequently present in sputum samples. The purification procedures involving solid phase extraction (SPE) based methods with both commercial Isolute-Florisil cartridges, and purpose designed molecularly imprinted polymeric materials (MIPs), resulted in cleaner chromatograms, while the mycocerosates are still present. The clean-up performed on solutions of PDIMs and cholesterol standards in petroleum ether show that, depending on the solvent mix and on the type of SPE used, the recovery of PDIMs is between 64 and 70%, whilst most of the cholesterol is removed from the system. When applied to petroleum ether extracts from representative sputum samples, the clean-up procedures resulted in recoveries of 36–68% for PDIMs, allowing some superior detection of the target analytes. PMID:25728371

  13. Passive extraction and clean-up of phenoxy acid herbicides in samples from a groundwater plume using hollow fiber supported liquid membranes.

    PubMed

    Liu, Jing-Fu; Toräng, Lars; Mayer, Philipp; Jönsson, Jan Ake

    2007-08-10

    Hollow fiber supported liquid membranes were applied for the passive extraction of phenoxy acid herbicides from water samples. Polypropylene hollow fiber membranes (240 microm i.d., 30 microm wall thickness, 0.05 microm pore size, 30 cm length) were impregnated with 2.0% tri-n-octylphosphine oxide (TOPO) in di-n-hexyl ether in the pores of the fiber wall to form a liquid membrane. They were then filled with basic solution in the lumen as acceptor and finally placed into the sample (donor). Complete extraction of phenoxy acid herbicides including 2,4-D, MCPA, dichlorprop, and mecoprop from an acidified sample (4 mL, adjusted to pH 1.5 with HCl) into basic acceptor (10 microL of 0.2M NaOH) was achieved after 4 h of shaking (100 rpm) resulting in an enrichment factor of 400 times. The acceptor was then neutralized by addition of HCl and injected into a HPLC system for the determination of the phenoxy acid herbicides. Environmentally relevant salinity (0-3.5% NaCl) and dissolved organic matter (0-25 mg/L of dissolved organic carbon) had no significant effect on the extraction. The method provided extraction efficiencies of more than 91%, detection limits of 0.3-0.6 microg/L, and combined extraction and clean up in one single step. This procedure was applied to determine aqueous concentrations of phenoxy acid herbicides in groundwater samples collected from an old dumping site (Cheminova, Denmark) with detected concentrations up to 5800 microg/L. Although the samples were very dirty with large amounts of suspended particles, non-aqueous phase liquids (NAPLs) and dissolved organic matters, good spike recoveries (80-126%) were obtained for 10 of the 11 samples.

  14. Determination of deoxynivalenol and deoxynivalenol-3-glucoside in wheat and barley using liquid chromatography coupled to mass spectrometry: on-line clean-up versus conventional sample preparation techniques.

    PubMed

    Nathanail, Alexis V; Sarikaya, Ebru; Jestoi, Marika; Godula, Michal; Peltonen, Kimmo

    2014-12-29

    In this study, we compared the performance of conventional sample preparation techniques used in mycotoxin analyses against automated on-line sample clean-up for the determination of deoxynivalenol (DON) and its conjugated derivative, deoxynivalenol-3-β-d-glucoside (D3G), in cereal grains. Blank wheat and barley samples were spiked with DON and D3G, extracted with a mixture of acetonitrile:water (84:16, v/v) and processed by one of the following: extract and shoot, MycoSep(®) 227 clean-up columns, MycoSep 227 with an additional acetonitrile elution step and centrifugal filtration, followed by analysis with liquid chromatography tandem mass spectrometry. Based on method performance characteristics and poor recoveries (<30%) obtained for the polar D3G with some techniques, the extract and shoot approach was chosen for the inter-laboratory method comparison study. Thus, the same spiked samples were analysed in parallel by another laboratory with an in-house validated on-line sample clean-up method, utilising TurboFlow™ chromatography coupled to high resolution mass spectrometry. Method validation was performed by determination of specificity, linearity, recovery, intra-day precision and the limits of detection and quantification. Matrix-matched linearity (R(2)>0.985) was established in the range of 100-1600 and 20-320μg/kg for DON and D3G, respectively. Average recoveries (%RSD) were acceptable with both methods for wheat and barley, ranging between 73% and 102% (3-12%) for DON and 72% and 98% (1-10%) for D3G. The benefit of using automated sample clean-up in comparison to extract and shoot is the ability to inject directly pure extracts into the mass spectrometer, offering faster analyses and improved sensitivity with minimum system maintenance.

  15. Ion Mobility Mass Spectrometry for Ion Recovery and Clean-Up of MS and MS/MS Spectra Obtained from Low Abundance Viral Samples

    NASA Astrophysics Data System (ADS)

    Harvey, David J.; Crispin, Max; Bonomelli, Camille; Scrivens, Jim H.

    2015-07-01

    Many samples of complex mixtures of N-glycans released from small amounts of material, such as glycoproteins from viruses, present problems for mass spectrometric analysis because of the presence of contaminating material that is difficult to remove by conventional methods without involving sample loss. This study describes the use of ion mobility for extraction of glycan profiles from such samples and for obtaining clean CID spectra when targeted m/z values capture additional ions from those of the target compound. N-glycans were released enzymatically from within SDS-PAGE gels, from the representative recombinant glycoprotein, gp120 of the human immunodeficiency virus, and examined by direct infusion electrospray in negative mode followed by ion mobility with a Waters Synapt G2 mass spectrometer (Waters MS-Technologies, Manchester, UK). Clean profiles of singly, doubly, and triply charged N-glycans were obtained from samples in cases where the raw electrospray spectra displayed only a few glycan ions as the result of low sample concentration or the presence of contamination. Ion mobility also enabled uncontaminated CID spectra to be obtained from glycans when their molecular ions displayed coincidence with ions from fragments or multiply charged ions with similar m/z values. This technique proved to be invaluable for removing extraneous ions from many CID spectra. The presence of such ions often produces spectra that are difficult to interpret. Most CID spectra, even those from abundant glycan constituents, benefited from such clean-up, showing that the extra dimension provided by ion mobility was invaluable for studies of this type.

  16. Ion Mobility Mass Spectrometry for Ion Recovery and Clean-Up of MS and MS/MS Spectra Obtained from Low Abundance Viral Samples.

    PubMed

    Harvey, David J; Crispin, Max; Bonomelli, Camille; Scrivens, Jim H

    2015-10-01

    Many samples of complex mixtures of N-glycans released from small amounts of material, such as glycoproteins from viruses, present problems for mass spectrometric analysis because of the presence of contaminating material that is difficult to remove by conventional methods without involving sample loss. This study describes the use of ion mobility for extraction of glycan profiles from such samples and for obtaining clean CID spectra when targeted m/z values capture additional ions from those of the target compound. N-glycans were released enzymatically from within SDS-PAGE gels, from the representative recombinant glycoprotein, gp120 of the human immunodeficiency virus, and examined by direct infusion electrospray in negative mode followed by ion mobility with a Waters Synapt G2 mass spectrometer (Waters MS-Technologies, Manchester, UK). Clean profiles of singly, doubly, and triply charged N-glycans were obtained from samples in cases where the raw electrospray spectra displayed only a few glycan ions as the result of low sample concentration or the presence of contamination. Ion mobility also enabled uncontaminated CID spectra to be obtained from glycans when their molecular ions displayed coincidence with ions from fragments or multiply charged ions with similar m/z values. This technique proved to be invaluable for removing extraneous ions from many CID spectra. The presence of such ions often produces spectra that are difficult to interpret. Most CID spectra, even those from abundant glycan constituents, benefited from such clean-up, showing that the extra dimension provided by ion mobility was invaluable for studies of this type.

  17. Coupling of acetonitrile deproteinization and salting-out extraction with acetonitrile stacking for biological sample clean-up and the enrichment of hydrophobic compounds (porphyrins) in capillary electrophoresis.

    PubMed

    Li, Qi; Huie, Carmen W

    2006-11-01

    A new sample pretreatment approach in CE was developed for concurrent biological sample clean-up and the concentration of hydrophobic compounds based on the combination of ACN deproteinization with salting-out extraction. Further enhancement in concentration detection sensitivity was achieved by coupling (offline) salting-out extraction with an online CE sample enrichment technique known as "ACN stacking". By optimizing the pH of salting-out extraction, a number of model compounds (hydrophobic porphyrins with clinical significances), i.e. zinc-protoporphyrin, protoporphyrin, and coproporphyrin (CP) III and I, can be efficiently extracted from the aqueous sample into a smaller volume organic solvent (ACN) phase and an enrichment factor of ca. 100 can be obtained. The pressure injection of the enriched ACN phase (containing ca.1% NaCl) into the CE capillary at 10% capillary volume resulted in additional concentration of the various hydrophobic porphyrins, allowing for a combined enrichment factor of ca.1000 to be obtained. Calibration curves obtained for the determination of a pair of positional isomers with significant diagnostic value, urinary CPIII and CPI, were found to be linear between 10-300 ng/mL (with R2 = 0.999), and LODs (absorbance detection at 400 nm) were ca. 0.8 ng/mL (1.1 nmol/L of CPIII or CPI). Based on a single salting-out extraction, intraday precisions (nine consecutive injections) for both CPIII and CPI (at spiked concentrations of 10-300 ng/mL into urine) in terms of migration time and peak area were found to be within the range of 0.2-0.5 and 0.8-2.9%, respectively.

  18. An improved clean-up strategy for simultaneous analysis of polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), and polychlorinated biphenyls (PCB) in fatty food samples.

    PubMed

    Pirard, Catherine; Focant, Jean-François; De, Pauw Edwin

    2002-01-01

    The study and extension of a simple automated clean-up method for polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) to a broad range of polychlorinated biphenyls (PCB) is described. The isolation of seven PCDD, ten PCDF, and three coplanar PCB (cPCB) is extended to eight monoortho substituted PCB and seven so-called "marker PCB" (Aroclor 1260) for fatty food samples. This enables quantification of 35 compounds - including all congeners with a WHO toxic equivalent factor (TEF)--in a single extraction and single purification step. The chromatographic behaviour of mono-ortho PCB and marker PCB on a variety of adsorbents, including basic alumina, has been studied. Partitioning of analytes through multi-column sequences is described and correlated with their structural and electronic properties, by use of molecular modelling calculations. The fractionation process available with the Power-Prep automated clean-up system enables rapid independent analysis of the different groups of compounds. Gas chromatography with high resolution mass spectrometry (GC-HRMS) is used for the PCDD/F and cPCB fraction and quadrupole ion-storage tandem in time mass spectrometry (GC-QISTMS) for analysis of the remaining PCB. A comparison study was performed on quality-control samples and real fatty food samples to evaluate the robustness of the new strategy compared with a reference method. On the basis of this simultaneous clean-up, a rapid simplified strategy for PCDD/F and selected PCB analysis determination is proposed for fatty food samples.

  19. Development of sample extraction and clean-up strategies for target and non-target analysis of environmental contaminants in biological matrices.

    PubMed

    Baduel, Christine; Mueller, Jochen F; Tsai, Henghang; Gomez Ramos, Maria Jose

    2015-12-24

    Recently, there has been an increasing trend towards multi-targeted analysis and non-target screening methods as a means to increase the number of monitored analytes. Previous studies have developed biomonitoring methods which specifically focus on only a small number of analytes with similar physico-chemical properties. In this paper, we present a simple and rapid multi-residue method for simultaneous extraction of polar and non-polar organic chemicals from biological matrices, containing up to 5% lipid content. Our method combines targeted multi-residue analysis using gas chromatography triple quadrupole mass spectrometry (GC-QqQ-MS/MS) and a multi-targeted analysis complemented with non-target screening using liquid chromatography coupled to a quadrupole time of flight mass spectrometry (LC-QTOF-MS/MS). The optimization of the chemical extraction procedure and the effectiveness of different clean-up methods were evaluated for two biological matrices: fish muscle (lipid content ∼2%) and breast milk (∼4%). To extract a wide range of chemicals, the partition/extraction procedure used for the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) approach was tested as the initial step for the extraction of 77 target compounds covering a broad compound domain. All the target analytes have different physico-chemical properties (log Kow ranges from -0.3 to 10) and cover a broad activity spectrum; from polar pesticides, pharmaceuticals, personal care products (PPCPs) to highly lipophilic chemicals such as polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and organochloride pesticides (OCPs). A number of options were explored for the clean-up of lipids, proteins and other impurities present in the matrix. Zirconium dioxide-based sorbents as dispersive solid-phase extraction (d-SPE) and protein-lipid removal filter cartridges (Captiva ND Lipids) provided the best results for GC-MS and LC-MS analysis

  20. Development of sample extraction and clean-up strategies for target and non-target analysis of environmental contaminants in biological matrices.

    PubMed

    Baduel, Christine; Mueller, Jochen F; Tsai, Henghang; Gomez Ramos, Maria Jose

    2015-12-24

    Recently, there has been an increasing trend towards multi-targeted analysis and non-target screening methods as a means to increase the number of monitored analytes. Previous studies have developed biomonitoring methods which specifically focus on only a small number of analytes with similar physico-chemical properties. In this paper, we present a simple and rapid multi-residue method for simultaneous extraction of polar and non-polar organic chemicals from biological matrices, containing up to 5% lipid content. Our method combines targeted multi-residue analysis using gas chromatography triple quadrupole mass spectrometry (GC-QqQ-MS/MS) and a multi-targeted analysis complemented with non-target screening using liquid chromatography coupled to a quadrupole time of flight mass spectrometry (LC-QTOF-MS/MS). The optimization of the chemical extraction procedure and the effectiveness of different clean-up methods were evaluated for two biological matrices: fish muscle (lipid content ∼2%) and breast milk (∼4%). To extract a wide range of chemicals, the partition/extraction procedure used for the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) approach was tested as the initial step for the extraction of 77 target compounds covering a broad compound domain. All the target analytes have different physico-chemical properties (log Kow ranges from -0.3 to 10) and cover a broad activity spectrum; from polar pesticides, pharmaceuticals, personal care products (PPCPs) to highly lipophilic chemicals such as polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and organochloride pesticides (OCPs). A number of options were explored for the clean-up of lipids, proteins and other impurities present in the matrix. Zirconium dioxide-based sorbents as dispersive solid-phase extraction (d-SPE) and protein-lipid removal filter cartridges (Captiva ND Lipids) provided the best results for GC-MS and LC-MS analysis

  1. Development of sample preparation method for auxin analysis in plants by vacuum microwave-assisted extraction combined with molecularly imprinted clean-up procedure.

    PubMed

    Hu, Yuling; Li, Yuanwen; Zhang, Yi; Li, Gongke; Chen, Yueqin

    2011-04-01

    A novel sample preparation method for auxin analysis in plant samples was developed by vacuum microwave-assisted extraction (VMAE) followed by molecularly imprinted clean-up procedure. The method was based on two steps. In the first one, conventional solvent extraction was replaced by VMAE for extraction of auxins from plant tissues. This step provided efficient extraction of 3-indole acetic acid (IAA) from plant with dramatically decreased extraction time, furthermore prevented auxins from degradation by creating a reduced oxygen environment under vacuum condition. In the second step, the raw extract of VMAE was further subjected to a clean-up procedure by magnetic molecularly imprinted polymer (MIP) beads. Owing to the high molecular recognition ability of the magnetic MIP beads for IAA and 3-indole-butyric acid (IBA), the two target auxins in plants can be selectively enriched and the interfering substance can be eliminated by dealing with a magnetic separation procedure. Both the VMAE and the molecularly imprinted clean-up conditions were investigated. The proposed sample preparation method was coupled with high-performance liquid chromatogram and fluorescence detection for determination of IAA and IBA in peas and rice. The detection limits obtained for IAA and IBA were 0.47 and 1.6 ng/mL and the relative standard deviation were 2.3% and 2.1%, respectively. The IAA contents in pea seeds, pea embryo, pea roots and rice seeds were determined. The recoveries were ranged from 70.0% to 85.6%. The proposed method was also applied to investigate the developmental profiles of IAA concentration in pea seeds and rice seeds during seed germination. PMID:20953778

  2. Determination of eight sulfonamides in bovine kidney by liquid chromatography/tandem mass spectrometry with on-line extraction and sample clean-up.

    PubMed

    Van Eeckhout, N; Perez, J C; Van Peteghem, C

    2000-01-01

    A sensitive, high performance liquid chromatography/tandem mass spectrometric (i.e. mass spectrometry/mass spectrometry; LC/MS/MS) method with on-line extraction and sample clean-up for the screening and confirmation of residues of sulfonamides in kidney is described. The sulfonamides are extracted from homogenized kidney with methanol. After centrifugation of the extract, an aliquot of the extract is directly injected on the LC/MS/MS system with further extraction and clean-up of the sample on-line. Detection of the analytes was achieved by positive electrospray ionization (ESI) followed by multiple reaction monitoring. For each sulfonamide the collisional decomposition of the protonated molecule to a common, abundant fragment ion was monitored. The method has been validated for sulfadimethoxine, sulfaquinoxaline, sulfamethazine, sulfamerazine, sulfathiazole, sulfamethoxazole, sulfadiazine and sulfapyridine. Calibration curves resulting from spiked blank kidney samples at the 10-200 microg/kg level showed good linear correlation. At the level of 50, 100 and 200 microg/kg both within- and between-day precision, as measured by relative standard deviation (RSD), were less than 16%. The limits of detection (LODs) ranged from 5 to 13.5 microg/kg. The recoveries ranged from 78 to 82%. The procedure provides a rapid, reliable and sensitive method for the determination of residues of sulfonamides in bovine kidney. The advantage of this method over existing methods is its decreased sample preparation and analysis time, which makes the method more suitable for routine analysis. PMID:11114046

  3. Multicriteria optimisation of a simultaneous supercritical fluid extraction and clean-up procedure for the determination of persistent organohalogenated pollutants in aquaculture samples.

    PubMed

    Rodil, R; Carro, A M; Lorenzo, R A; Cela, R

    2007-04-01

    A useful tool based on a single-step extraction and clean-up procedure for the determination of 15 organohalogenated pollutants (including brominated flame retardants) in aquaculture samples, using aluminium oxide basic and acidic silica gel in the supercritical extraction cell followed by gas chromatography with electron capture detection or mass spectrometry has been developed. This effective clean-up step ensures a minimum of chromatographic difficulties related to complex matrix components such as aquaculture feed. The extraction procedure has been screened by a fractional factorial design for the preliminary statistically significant parameters. The factors selected were extraction temperature, pressure, static extraction time, dynamic extraction time and carbon dioxide flow rate. The Doehlert design, followed by a multicriteria decision-making strategy, was then performed in order to determine the optimum conditions for the two most significant factors: pressure (165 bar) and dynamic extraction time (27 min). Under optimal conditions, the procedure developed with GC-MS/MS provides an excellent linearity, detection (0.01-0.2 ng g(-1)) and quantification limits (0.05-0.8 ng g(-1)) for most of the analytes investigated. The feasibility of the proposed supercritical fluid extraction method was validated by analysing two reference materials and fish feed and shellfish samples with satisfactory results. PMID:17123577

  4. High-performance liquid chromatographic determination of ochratoxin A in artificially contaminated cocoa beans using automated sample clean-up.

    PubMed

    Hurst, W J; Martin, R A

    1998-06-12

    A HPLC method is described for the analysis of ochratoxin A at low-ppb levels in samples of artificially contaminated cocoa beans. The samples are extracted in a mixture of methanol-water containing ascorbic acid, adjusted to pH and evaporated to dryness. Samples in this state are then placed onto a Benchmate sample preparation workstation where C18 solid-phase extraction operations are performed. The resulting materials are evaporated to dryness and analyzed by reversed-phase HPLC with fluorescence detection. The method was evaluated for accuracy and precision with R.S.D.s for multiple injections of sample and standard calculated to 1.1% and 2.5% for sample and standard, respectively. Recoveries of ochratoxin A added to cocoa beans ranged from 87-106% over the range of the assay.

  5. Supercritical fluid extraction as an on-line clean-up technique for determination of riboflavin vitamins in food samples by capillary electrophoresis with fluorimetric detection.

    PubMed

    Zougagh, Mohammed; Ríos, Angel

    2008-08-01

    An automatic method for the separation and determination of riboflavin (RF) vitamins (RF, flavin mononucleotide and flavin adenine dinucleotide) in food samples (chicken liver, tablet and powder milk) is proposed. The method is based on the on-line coupling of a supercritical fluid extractor (SFE) with a continuous flow-CE system with guided optical fiber fluorimetric detection (CF-CE-FD). The whole SFE-CF-CE-FD arrangement allowed the automatic treatment of food samples (clean-up of the sample followed by the extraction of the analytes), and the direct introduction of a small volume of the extracted plug to the CE-FD system for the determination of RF vitamins. Fluorescence detection introduced an appropriated sensitivity and contributed to avoid interferences of nonfluorescent polar compounds coming from the matrix samples in the extracted plug. Electrophoretic responses were linear within the 0.05-1 microg/g range, whereas the detection limits of RF vitamins were in the 0.036-0.042 microg/g range. The proposed arrangement opens up interesting prospects for the direct determination of polar analytes in complex samples with a good throughput and high level of automation.

  6. Preparation and characterization of molecularly imprinted polymer for di(2-ethylhexyl) phthalate: application to sample clean-up prior to gas chromatographic determination.

    PubMed

    Shaikh, Huma; Memon, Najma; Khan, Hamayun; Bhanger, M I; Nizamani, S M

    2012-07-20

    The molecularly imprinted polymer (MIP) selective for di(2-ethylhexyl) phthalate (DEHP) an environmental endocrine disruptor was prepared by suspension polymerization using methacrylamide as functional monomer and N,N'-methylene-bis-acrylamide as cross-linker. The imprinted polymer was employed for solid-phase extraction of DEHP from water samples of environmental importance and characterized by FT-IR and SEM. The adsorption properties of the imprinted polymer were demonstrated by equilibrium rebinding experiments, Pseudo-second-order kinetic model, Sips isotherm and Scatchard analysis. The reusability of MIP was checked for at least six repeated batch adsorption cycles and the results showed almost no deterioration in the adsorption capacity. The competitive recognition studies were performed with DEHP and structurally similar compounds; dimethyl phthalate (DMP), diethyl phthalate (DEP), and dibutyl phthalate (DBP). The imprinting factor (IF) of DEHP was found to be 12.86 which was much higher than the imprinting factors (IF) of other phthalates. A method constituted by molecularly imprinted solid-phase extraction (MISPE) with GC-FID was developed for DEHP analysis in water samples under very simple conditions. Sample loading and desorption conditions were also optimized. The MISPE method's linearity ranged from 0.035 to 3.0 μg ml⁻¹ with r² = 0.9998. Intra-assay, interassay precision and accuracy ranged from 0.0168% to 1.017%, 1.130% to 4.799% and 94.98% to 99.35%, respectively. The LOD and LOQ were found to be 0.011 and 0.035 μg ml⁻¹, respectively. Synthesized MIP was employed in MISPE for cleaning up the spiked river water samples prior to gas chromatographic analysis. The river samples were found to contain DEHP in the range of 1.4 × 10⁻³ to 0.349 μg ml⁻¹. PMID:22673816

  7. TRACKING CLEAN UP AT HANFORD

    SciTech Connect

    CONNELL, C.W.

    2005-05-27

    The Hanford Federal Facility Agreement and Consent Order, known as the ''Tri-Party Agreement'' (TPA), is a legally binding agreement among the US Department of Energy (DOE), The Washington State Department of Ecology, and the US Environmental Protection Agency (EPA) for cleaning up the Hanford Site. Established in the 1940s to produce material for nuclear weapons as part of the Manhattan Project, Hanford is often referred to as the world's large environmental cleanup project. The Site covers more than 580 square miles in a relatively remote region of southeastern Washington state in the US. The production of nuclear materials at Hanford has left a legacy of tremendous proportions in terms of hazardous and radioactive waste. From a waste-management point of view, the task is enormous: 1700 waste sites; 450 billion gallons of liquid waste; 70 billion gallons of contaminated groundwater; 53 million gallons of tank waste; 9 reactors; 5 million cubic yards of contaminated soil; 22 thousand drums of mixed waste; 2.3 tons of spent nuclear fuel; and 17.8 metric tons of plutonium-bearing material and this is just a partial listing. The agreement requires that DOE provide the results of analytical laboratory and non-laboratory tests/readings to the lead regulatory agency to help guide then in making decisions. The agreement also calls for each signatory to preserve--for at least ten years after the Agreement has ended--all of the records in it, or its contractors, possession related to sampling, analysis, investigations, and monitoring conducted. The Action Plan that supports the TPA requires that Ecology and EPA have access to all data that is relevant to work performed, or to be performed, under the Agreement. Further, the Action Plan specifies two additional requirements: (1) that EPA, Ecology and their respective contractor staffs have access to all the information electronically, and (2) that the databases are accessible to, and used by, all personnel doing TPA

  8. Simultaneous pressurized enzymatic hydrolysis extraction and clean up for arsenic speciation in seafood samples before high performance liquid chromatography-inductively coupled plasma-mass spectrometry determination.

    PubMed

    Moreda-Piñeiro, Jorge; Alonso-Rodríguez, Elia; Moreda-Piñeiro, Antonio; Moscoso-Pérez, Carmen; Muniategui-Lorenzo, Soledad; López-Mahía, Purificación; Prada-Rodríguez, Darío; Bermejo-Barrera, Pilar

    2010-10-29

    The feasibility of pressurized conditions to assist enzymatic hydrolysis of seafood tissues for arsenic speciation was novelty studied. A simultaneous in situ (in cell) clean-up procedure was also optimized, which speeds up the whole sample treatment. Arsenic species (As(III), MMA, DMA, As(V), AsB and AsC) were released from dried seafood tissues using pepsin as a protease, and the arsenic species were separated/quantified by anion exchange high performance liquid chromatography (HPLC) coupled to inductively coupled plasma-mass spectrometry (ICP-MS). Variables inherent to the enzymatic activity (pH, temperature and ionic strength), the amount of enzyme (pepsin), and factors affecting pressurization (pressure, static time, number of cycles and amount of dispersing agent, C-18) were fully evaluated. Pressurized assisted enzymatic hydrolysis (PAEH) with pepsin can be finished after few minutes (two cycles of 2 min each one plus 3 min to reach the hydrolysis temperature of 50 °C). A total sample solubilisation is not achieved after the procedure, however it is efficient enough for breaking down certain bonds of bio-molecules and for releasing arsenic species. The developed method has been found to be precise (RSDs lower than 6% for As(III), DMA and As(V); and 3% for AsB) and sensitive (LOQs of 18.1, 36.2, 35.7, 28.6, 20.6 and 22.5 ng/g for As(III), MMA, DMA, As(V), AsB and AsC, respectively). The optimized methodology was successfully applied to different certified reference materials (DORM-2 and BCR 627) which offer certified AsB and DMA contents, and also to different seafood products (mollusks, white fishes and cold water fishes).

  9. An evaluation method for determination of non-polar pesticide residues in animal fat samples by using dispersive solid-phase extraction clean-up and GC-MS.

    PubMed

    Castillo, Mercedes; González, Carmen; Miralles, Ana

    2011-05-01

    A rapid and easy method has been proposed, optimized and evaluated for quantitative determination at trace level of a representative group of non-polar pesticides in fat samples. The method includes n-hexane-saturated acetonitrile extraction, fat precipitation by cooling pre clean-up followed by dispersive solid-phase extraction (d-SPE) based on QuEChERS procedure clean-up. Determination was performed by gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) mode. Efficiency of the d-SPE clean-up step was evaluated by comparison with fat oxidation treatment and gel permeation chromatography. Different combinations of d-SPE extraction reagents and sample amounts were tested in order to minimize matrix co-extractives and interferences. Best recoveries were obtained with 1200 mg of MgSO(4), 400 mg of end-capped C(18), 400 mg of PSA and 1 g of sample amount. SIM method, matrix effect, precision, and accuracy were evaluated with spiked pork fat samples for 38 representative pesticides. Results of this study showed that this technique is applicable in routine analysis for its application into monitoring programs. It simplifies time-consuming clean-up steps and allows a satisfactory long-term chromatographic performance.

  10. Analysis of neuropeptide Y and its metabolites by high-performance liquid chromatography-electrospray ionization mass spectrometry and integrated sample clean-up with a novel restricted-access sulphonic acid cation exchanger.

    PubMed

    Racaityte, K; Lutz ESM; Unger, K K; Lubda, D; Boos, K S

    2000-08-18

    A novel restricted access cation exchanger with sulphonic acid groups at the internal surface was proven to be highly suitable in the sample clean up of peptides on-line coupled to HPLC-electrospray ionization (ESI)-MS. Neuropeptide Y (NPY) and several of its fragments in plasma were subjected to the sample clean-up procedure. The peptides were eluted by a step gradient from the restricted access column, applying 10 mM phosphate buffer pH 3.5 from 5 to 20% (v/v) of acetonitrile with 1 M NaCl and transferred to a Micra ODS II column (33x4.6 mm). The separation of the peptides and their fragments was performed by a linear gradient from 20 to 60% (v/v) acetonitrile in water with 0.1% formic acid and 0.01% trifluoroacetic acid in 4 min at a flow-rate of 0.75 ml/min. An integrated and completely automated system composed of sample clean up-HPLC-ESI-MS was used to analyze real life samples. The sample volumes ranged between 20 and 100 microl. Peaks due to the fragments NPY 1-36, 3-36 and 13-36 in porcine plasma were identified by ESI-MS. The limit of detection was in the 5 nmol/ml range. The total analysis required 21 min and allowed the direct injection of plasma.

  11. Liquid-phase microextraction in a microfluidic-chip--high enrichment and sample clean-up from small sample volumes based on three-phase extraction.

    PubMed

    Ramos Payán, María D; Jensen, Henrik; Petersen, Nickolaj Jacob; Hansen, Steen Honoré; Pedersen-Bjergaard, Stig

    2012-07-20

    In this work, a microfluidic-chip based system for liquid-phase microextraction (LPME-chip) was developed. Sample solutions were pumped into the LPME-chip with a micro-syringe pump at a flow rate of 3-4 μL min(-1). Inside the LPME chip, the sample was in direct contact with a supported liquid membrane (SLM) composed of 0.2 μL dodecyl acetate immobilized in the pores of a flat membrane of polypropylene (25 μm thickness). On the other side of the SLM, the acceptor phase was present. The acceptor phase was either pumped at 1 μL min(-1) during extraction or kept stagnant (stop-flow). Amitriptyline, methadone, haloperidol, loperamide, and pethidine were selected as model analytes, and they were extracted from alkaline sample solution, through the SLM, and into 10 mM HCl or 100mM HCOOH functioning as acceptor phase. Subsequently, the acceptor phase was either analyzed off-line by capillary electrophoresis for exact quantification, or on-line by UV detection or electrospray ionization mass spectrometry for time profiling of concentrations. The LPME-chip was found to be highly effective, and extraction efficiencies were in the range of 52-91%. When the flow of acceptor phase was turned off during extraction (stop-flow), analyte enrichment increased linearly with the extraction time. After 10 min as an example, amitriptyline was enriched by a factor of 42 from only 30 μL sample solution, and after 120 min amitriptyline was enriched by a factor of 500 from 320 μL sample solution. This suggested that the LPME-chip has great potentials for very efficient analyte enrichments from limited sample volumes in the future.

  12. New method for the determination of parabens and bisphenol A in human milk samples using ultrasound-assisted extraction and clean-up with dispersive sorbents prior to UHPLC-MS/MS analysis.

    PubMed

    Rodríguez-Gómez, R; Dorival-García, N; Zafra-Gómez, A; Camino-Sánchez, F J; Ballesteros, O; Navalón, A

    2015-06-15

    A sensitive and accurate analytical method for the determination of methyl-, ethyl-, propyl- and butylparaben and bisphenol A in human milk samples has been developed and validated. The combination of ultrasound-assisted extraction (UAE) and a simplified and rapid clean-up technique that uses sorbent materials has been successfully applied for the preparation of samples prior to ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis. The analytes were extracted from freeze-dried human milk samples using acetonitrile and ultrasonic radiation (three 15-min cycles at 70% amplitude), and further cleaned-up with C18 sorbents. The most influential parameters affecting the UAE method and the clean-up steps were optimized using design of experiments. Negative electrospray ionization (ESI) in the selected reaction monitoring (SRM) mode was used for MS detection. The use of two reactions for each compound allowed simultaneous quantification and identification in one run. The analytes were separated in less than 10min. Deuterium-labeled ethylparaben-d5 (EPB-d5) and deuterium-labeled bisphenol A-d16 (BPA-d16) were used as surrogates. The limits of quantification ranged from 0.4 to 0.7ngmL(-1), while inter- and intra-day variability was under 11.1% in all cases. In the absence of certified reference materials, recovery assays with spiked samples using matrix-matched calibration were used to validate the method. Recovery rates ranged from 93.8% to 112.2%. The proposed method was satisfactorily applied for the determination of four selected parabens and bisphenol A in human milk samples obtained from nursing mothers living in the province of Granada (Spain). PMID:25942557

  13. New method for the determination of parabens and bisphenol A in human milk samples using ultrasound-assisted extraction and clean-up with dispersive sorbents prior to UHPLC-MS/MS analysis.

    PubMed

    Rodríguez-Gómez, R; Dorival-García, N; Zafra-Gómez, A; Camino-Sánchez, F J; Ballesteros, O; Navalón, A

    2015-06-15

    A sensitive and accurate analytical method for the determination of methyl-, ethyl-, propyl- and butylparaben and bisphenol A in human milk samples has been developed and validated. The combination of ultrasound-assisted extraction (UAE) and a simplified and rapid clean-up technique that uses sorbent materials has been successfully applied for the preparation of samples prior to ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis. The analytes were extracted from freeze-dried human milk samples using acetonitrile and ultrasonic radiation (three 15-min cycles at 70% amplitude), and further cleaned-up with C18 sorbents. The most influential parameters affecting the UAE method and the clean-up steps were optimized using design of experiments. Negative electrospray ionization (ESI) in the selected reaction monitoring (SRM) mode was used for MS detection. The use of two reactions for each compound allowed simultaneous quantification and identification in one run. The analytes were separated in less than 10min. Deuterium-labeled ethylparaben-d5 (EPB-d5) and deuterium-labeled bisphenol A-d16 (BPA-d16) were used as surrogates. The limits of quantification ranged from 0.4 to 0.7ngmL(-1), while inter- and intra-day variability was under 11.1% in all cases. In the absence of certified reference materials, recovery assays with spiked samples using matrix-matched calibration were used to validate the method. Recovery rates ranged from 93.8% to 112.2%. The proposed method was satisfactorily applied for the determination of four selected parabens and bisphenol A in human milk samples obtained from nursing mothers living in the province of Granada (Spain).

  14. 48 CFR 36.512 - Cleaning up.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Cleaning up. 36.512... CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Contract Clauses 36.512 Cleaning up. The contracting officer shall insert the clause at 52.236-12, Cleaning Up, in solicitations and contracts when a...

  15. 48 CFR 36.512 - Cleaning up.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 1 2014-10-01 2014-10-01 false Cleaning up. 36.512... CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Contract Clauses 36.512 Cleaning up. The contracting officer shall insert the clause at 52.236-12, Cleaning Up, in solicitations and contracts when a...

  16. 48 CFR 36.512 - Cleaning up.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Cleaning up. 36.512... CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Contract Clauses 36.512 Cleaning up. The contracting officer shall insert the clause at 52.236-12, Cleaning Up, in solicitations and contracts when a...

  17. 48 CFR 36.512 - Cleaning up.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false Cleaning up. 36.512... CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Contract Clauses 36.512 Cleaning up. The contracting officer shall insert the clause at 52.236-12, Cleaning Up, in solicitations and contracts when a...

  18. 48 CFR 36.512 - Cleaning up.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Cleaning up. 36.512... CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Contract Clauses 36.512 Cleaning up. The contracting officer shall insert the clause at 52.236-12, Cleaning Up, in solicitations and contracts when a...

  19. Positive- and negative-ion mass spectrometry of diphenylmethane antihistaminics and their analogues and rapid clean-up of them from biological samples.

    PubMed

    Seno, H; Hattori, H; Kumazawa, T; Suzuki, O

    1993-12-01

    Positive-ion electron impact (PIEI), positive-ion chemical ionization (PICI) and negative-ion chemical ionization (NICI) mass spectra are presented for 15 compounds of diphenylmethane antihistaminics and their analogues, and each fragmentation pathway was analyzed. In the PIEI mode, molecular peaks were very small or missing for most compounds. Peaks at m/z 58, due to a dimethylaminomethyl group liberated, constituted base peaks in five compounds. Peaks at m/z 165 and/or 167, due to diaromatic rings plus a methyl group, appeared in most compounds. In the PICI mode, peaks due to M+H and M+C2H5 appeared in all compounds. Peaks due to diaromatic rings plus a methyl or ethyl group constituted base peaks in five compounds, which had an ether bond in their structures. In the NICI mode, anions at m/z M-H appeared in most compounds. Peaks at m/z 35 were observed for compounds having a chlorine group in their structures. Detection limits for total ion monitoring of these compounds were 20-50 ng on column in the PIEI mode, 100-200 ng in the PICI mode and 500-1000 ng in the NICI mode. A rapid and simple clean-up procedure of these drugs with use of Sep-Pak C18 cartridges is also presented. The drugs could be detected by gas chromatography with DB-1 and DB-17 capillary columns with satisfactory separation from impurities in their underivatized forms. The recovery of the drugs, which had been added to whole blood and urine, was more than 60% except for meclizine. PMID:8307529

  20. Cleaning Up Our Drinking Water

    SciTech Connect

    Manke, Kristin L.

    2007-08-01

    Imagine drinking water that you wring out of the sponge you’ve just used to wash your car. This is what is happening around the world. Rain and snow pass through soil polluted with pesticides, poisonous metals and radionuclides into the underground lakes and streams that supply our drinking water. “We need to understand this natural system better to protect our groundwater and, by extension, our drinking water,” said Pacific Northwest National Laboratory’s Applied Geology and Geochemistry Group Manager, Wayne Martin. Biologists, statisticians, hydrologists, geochemists, geologists and computer scientists at PNNL work together to clean up contaminated soils and groundwater. The teams begin by looking at the complexities of the whole environment, not just the soil or just the groundwater. PNNL researchers also perform work for private industries under a unique use agreement between the Department of Energy and Battelle, which operates the laboratory for DOE. This research leads to new remediation methods and technologies to tackle problems ranging from arsenic at old fertilizer plants to uranium at former nuclear sites. Our results help regulators, policy makers and the public make critical decisions on complex environmental issues.

  1. QuEChERS-based extraction with dispersive solid phase extraction clean-up using PSA and ZrO2-based sorbents for determination of pesticides in bovine milk samples by HPLC-DAD.

    PubMed

    Rejczak, Tomasz; Tuzimski, Tomasz

    2017-02-15

    In this study, a quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction technique was adapted to develop a simple sample treatment for multi-residue pesticide analysis in milk samples. The proposed method is based on liquid-liquid partitioning with acetonitrile followed by dispersive solid phase extraction clean-up using primary secondary amine along with zirconia-coated silica particles for extract purification. Identification and quantification of 30 pesticides was conducted via high performance liquid chromatography with diode-array detection (HPLC-DAD). Recoveries were from 70 to 100% for the vast majority of the analytes, with relative standard deviations less than 20% being observed. HPLC-DAD provided suitable linearity, precision and accuracy. For 28 of 30 analytes in the study method limit of quantification values (mLOQs) comply with the most recent European Union guidelines for the maximum residue levels (MRLs) in milk. Negligible matrix effect was observed due to efficient extract clean-up with ZrO2-based sorbents.

  2. QuEChERS-based extraction with dispersive solid phase extraction clean-up using PSA and ZrO2-based sorbents for determination of pesticides in bovine milk samples by HPLC-DAD.

    PubMed

    Rejczak, Tomasz; Tuzimski, Tomasz

    2017-02-15

    In this study, a quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction technique was adapted to develop a simple sample treatment for multi-residue pesticide analysis in milk samples. The proposed method is based on liquid-liquid partitioning with acetonitrile followed by dispersive solid phase extraction clean-up using primary secondary amine along with zirconia-coated silica particles for extract purification. Identification and quantification of 30 pesticides was conducted via high performance liquid chromatography with diode-array detection (HPLC-DAD). Recoveries were from 70 to 100% for the vast majority of the analytes, with relative standard deviations less than 20% being observed. HPLC-DAD provided suitable linearity, precision and accuracy. For 28 of 30 analytes in the study method limit of quantification values (mLOQs) comply with the most recent European Union guidelines for the maximum residue levels (MRLs) in milk. Negligible matrix effect was observed due to efficient extract clean-up with ZrO2-based sorbents. PMID:27664630

  3. Analysis of highly saline samples by capillary zone electrophoresis: enhanced direct UV detection of inorganic anions using on-capillary preconcentration and clean-up techniques.

    PubMed

    Timerbaev, A R; Fukushi, K; Miyado, T; Ishio, N; Saito, K; Motomizu, S

    2000-08-01

    The ability to analyze samples with disparate levels of analyte and matrix ions is among the important benefits defining the practical utility of modern capillary electrophoresis. To compensate for the sensitivity limitations regarding trace-level inorganic anions, a number of on-line approaches that should offer an improved S/N ratio in direct UV detection were examined. The novel use of reversed pre-electrophoresis (at the applied voltage opposite to the separation voltage) made it possible to efficiently remove the most part of high chloride levels from the sample and hence to lower the background signal and to inject increased quantities of fast analyte anions. Specifically, by taking these advantages the sensitivity response of iodide was improved by a factor of 5 over normal CE mode. Using isotachophoretic sample stacking, a two-fold increase in detectability was obtained for moderately mobile anions, nitrate and nitrite, that corresponds to the minimum detectable concentrations close to their natural occurrences in seawater. Furthermore, field-amplified sample injection at increased electrolyte-to-sample matrix concentration ratios enabled the maximum S/N enhancement, with detection limits at the level of 10(-6) M and lower in the presence of > or = 5 x 10(4)-fold molar excess of chloride. PMID:10949497

  4. On-line coupling of sequential injection extraction with restricted-access materials for sample clean-up and analysis of drugs in biological matrix.

    PubMed

    Satínský, Dalibor; Sklenárová, Hana; Huclová, Jitka; Karlícek, Rolf

    2003-04-01

    In this contribution, the on-line coupling of solid phase extraction (SPE), based on a restricted-access material (RAM), with sequential injection technique (SIA) for the analysis of biological samples, is described. The SIA-RAM system was tested with a new potential antileucotrienic drug (VUFB-19363 (Quinlukast)) for serum analysis. The method is based on SPE with the novel internal-surface reversed-phase column packing material-alkyl-diol silica (ADS). The supports tolerate direct and repetitive injection of proteinaceous fluids (plasma, serum) and allow reversed-phase partitioning at the internal surface. A column packed with a 25 microm C18 alkyl-diol support was used for direct serum injection. Using a 6-port selection valve and the system of three mobile phases, the polar matrix compounds and metabolites are removed by sequentially aspirated mobile phases with lower content of the organic part (methanol-water (2:98) and following acetonitrile-water (20:80)) to the waste, and then, the analyte enriched on the column is eluted by a strong mobile phase (acetonitrile-methanol-water (40:20:40)) to the UV detector without transfer loss. With the fully automated SIA system, a total analysis time of less than 10 min was achieved. The only off-line sample pre-treatment step required to remove particulate matter was centrifugation. The studies showed a range of linearity (2-40 microg ml(-1)) and a high recovery (93.6-96.8%) of drug from the biological matrix with coefficients of variation (RSD) less than 5.0% (n = 6). This paper introduces a new, simple and robust analytical technique suitable for screening determination and direct analysis of drugs in biological materials.

  5. Non-particulate (continuous bed or monolithic) restricted-access reversed-phase media for sample clean-up and separation by capillary-format liquid chromatography.

    PubMed

    Jarmalaviciene, Reda; Kornysova, Olga; Westerlund, Douglas; Maruska, Audrius

    2003-11-01

    Restricted-access reversed-phase non-particulate (continuous bed or monolithic) stationary phases of different hydrophobicity synthesized in 100 microm i.d. fused silica capillaries have been evaluated. A specific property of restricted-access media (RAM) is that they interact with small analytes and exclude big molecules, e.g. proteins, from access to the active sites and adsorption on the surface. This dual property facilitates direct injection of biological fluids for drug or drug-metabolite analysis. Different RAM and RAM-precursor capillary columns were tested to assess the influence of chromatographic bed morphology on loadability. Inverse size-exclusion chromatography was used for investigation of pore structural properties of the capillary-format continuous beds. The data obtained were used to discuss the mechanism of separation of the biological samples using capillary columns and to propose a model for the topochemical architecture of the RAM investigated. Different morphology of the non-particulate reversed-phase precursors resulted in two types of RAM material shielded with hydrophilic polymer, classified as homogeneous or heterogeneous topochemistry stationary phases. Capillary columns were applied for chromatography of biological fluids. High resolution was obtained, without the need for column switching, when capillary columns operated in gradient conditions. Extensive evaluation of the chromatographic properties (hydrophobicity, efficiency, separation impedance, and loadability) of the non-particulate reversed-phase materials was performed before and after shielding with hydrophilic polymer to generate restricted-access properties. Minor changes of hydrophobicity, efficiency, or separation impedance were observed after the shielding. PMID:14513200

  6. Supercritical fluid extraction as an on-line clean-up technique for rapid amperometric screening and alternative liquid chromatography for confirmation of paraquat and diquat in olive oil samples.

    PubMed

    Zougagh, M; Bouabdallah, M; Salghi, R; Hormatallah, A; Rios, A

    2008-09-12

    A rapid and simple method for the direct screening of paraquat (PQ) and diquat (DQ) in olive oil samples is proposed. The sample screening method involves supercritical fluid extraction (SFE) (clean-up followed by the extraction of the analytes) followed by continuous flow electrochemical detection. Those samples for which the total concentration is close to or above the threshold limit established by the Columbian Society for Social Protection (0.05 microg g(-1)) are subsequently analyzed by liquid chromatography (LC) with diode array detection (DAD). This confirmation method allows the determination of PQ and DQ in the range between 0.04 and 1.0 microg g(-1), with average relative standard deviations lower than 3.5%, and 0.003 and 0.002 microg g(-1) detection limits for PQ and DQ, respectively. The proposed arrangement opens up interesting prospects for the direct determination of polar pesticides in complex samples with a good throughput and a high level of automation.

  7. Exhaust gas clean up process

    DOEpatents

    Walker, R.J.

    1988-06-16

    A method of cleaning an exhaust gas containing particulates, SO/sub 2/ and NO/sub x/ is described. The method involves prescrubbing with water to remove HCl and most of the particulates, scrubbing with an aqueous absorbent containing a metal chelate and dissolved sulfite salt to remove NO/sub x/ and SO/sub 2/, and regenerating the absorbent solution by controlled heating, electrodialysis and carbonate salt addition. The NO/sub x/ is removed as N/sub 2/ gas or nitrogen sulfonate ions and the oxides of sulfur are removed as a valuable sulfate salt. 4 figs.

  8. Exhaust gas clean up process

    DOEpatents

    Walker, Richard J.

    1989-01-01

    A method of cleaning an exhaust gas containing particulates, SO.sub.2 and NO.sub.x includes prescrubbing with water to remove HCl and most of the particulates, scrubbing with an aqueous absorbent containing a metal chelate and dissolved sulfite salt to remove NO.sub.x and SO.sub.2, and regenerating the absorbent solution by controlled heating, electrodialysis and carbonate salt addition. The NO.sub.x is removed as N.sub.2 or nitrogen-sulfonate ions and the oxides of sulfur are removed as a vaulable sulfate salt.

  9. Clean-up of lead contaminated sites - the Ontario experience

    SciTech Connect

    Rinne, R.J.; Linzon, S.N.; Stokes, P.M.

    1986-01-01

    Toronto Health Department testing of children residing near one of the smelters has continued to reveal a number of instances of elevated blood lead levels although levels have decreased significantly since the mid-1970's. Air lead emissions from the smelter have been controlled to the point where excursions of the 5 ug/m/sup 3/ Ontario ambient air quality criterion are infrequent. City of Toronto health authorities have expressed the concern that soil lead levels above 1000 ug/g may be associated with elevated blood lead levels in children. In response to this concern, the Ontario Ministry of the Environment conducted soil sampling on 389 residential properties near the smelter in 1985. The Phytoxicology Section of the Ontario Ministry of the Environment has recently recommended soil clean-up levels of lead and other metals for the decommissioning and redevelopment of industrially-contaminated sites. The recommended soil clean-up levels for lead are 1000 ug/g and 500 ug/g for industrial and residential redevelopment, respectively. The 500 ug/g residential clean-up criterion has been applied to the clean-up of land contaminated by an abandoned tannery and lead smelter complex in the city of Kingston, Ontario. 34 references, 4 tables.

  10. Fully automated method for the liquid chromatographic-tandem mass spectrometric determination of cyproterone acetate in human plasma using restricted access material for on-line sample clean-up.

    PubMed

    Christiaens, B; Fillet, M; Chiap, P; Rbeida, O; Ceccato, A; Streel, B; De Graeve, J; Crommen, J; Hubert, Ph

    2004-11-12

    A new automated method for the quantitative analysis of cyproterone acetate (CPA) in human plasma has been developed using on-line solid phase extraction (SPE) prior to the LC-MS/MS determination. The method was based on the use of a pre-column packed with internal-surface reversed-phase material (LiChrospher RP-4 ADS, 25 mm x 2 mm) for sample clean-up coupled to LC separation on an octadecyl silica stationary phase by means of a column switching system. A 30 microl plasma sample volume was injected directly onto the pre-column using a mixture of water, acetonitrile and formic acid (90:10:0.1 (v/v/v)) adjusted to pH 4.0 with diluted ammonia as washing liquid. The analyte was then eluted in the back-flush mode with the LC mobile phase consisting of water, methanol and formic acid (10:90:0.1 (v/v/v)). The dispensing flow rates of the washing liquid and the LC mobile phase were 300 microl min(-1). Medroxyprogesterone acetate (MPA) was used as internal standard. The MS ionization of the analytes was achieved using electrospray (ESI) in the positive ion mode. The pseudomolecular ionic species of CPA and MPA (417.4 and 387.5) were selected to generate daughter ions at 357.4 and 327.5, respectively. Finally, the developed method was validated according to a new approach using accuracy profiles as a decision tool. Very good results with respect to accuracy, detectability, repeatability, intermediate precision and selectivity were obtained. The LOQ of cyproterone acetate was 300 pg ml(-1).

  11. Cleaning up soils contaminated with petroleum hydrocarbons

    SciTech Connect

    Arniella, E.F. ); Holley, R.E. )

    1991-08-01

    This article describes one new technology used to clean up soils contaminated with petroleum hydrocarbons from underground storage tanks. Topics covered include cleanup criteria, soil remediation technologies, air stripping-soil venting system and process design and performance. This contaminated site was located in the Atlanta, Georgia metropolitan area.

  12. Myelodysplastic syndromes in Chernobyl clean-up workers.

    PubMed

    Gluzman, Daniil F; Sklyarenko, Lilia M; Koval, Stella V; Rodionova, Nataliia K; Zavelevich, Michael P; Ivanivskaya, Tetiana S; Poludnenko, Liudmyla Yu; Ukrainskaya, Nataliia I

    2015-10-01

    The studies of the recent decades posed the question of the association between radiation exposure and myelodysplastic syndromes (MDS). This association has been proved in secondary MDS originating upon exposure to chemotherapeutics and/or radiation therapy. The long-term study in Japanese atomic (A)-bomb survivors demonstrated the significant linear dose-response for MDS confirming the link between radiation exposure and this form of hematopoietic malignancies. All these findings provide the strong basis for studying MDS in the persons exposed to radiation following the Chernobyl disaster, especially those in the cohort of Chernobyl clean-up workers of 1986-1987. The data on MDS among Chernobyl clean-up workers (1986-1987) diagnosed in 1996-2012 at the reference laboratory of RE Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology are summarized. MDS cases were diagnosed in 23 persons (21 males and 2 females) having been exposed to radiation as clean-up workers of 1986-1987. Refractory anemia (RA) has been detected in 13, refractory anemia with ring sideroblasts (RARS)-in 2, and refractory anemia with excess blasts (RAEB)-in 8 patients. The median age of those MDS patients was 62.0 years. In addition, 5 cases of chronic myelomonocytic leukemia (CMML) were recorded in the group of Chernobyl clean-up workers with the median time of 14.8 years from 1986-1987 to diagnosis. The association between radiation exposure and MDS is discussed. The suggested life-long risk for myelodysplastic syndromes among A-bomb survivors in Japan highlights the importance of the continuing follow-up studies in the affected populations in the post-Chernobyl period. PMID:26208666

  13. Myelodysplastic syndromes in Chernobyl clean-up workers.

    PubMed

    Gluzman, Daniil F; Sklyarenko, Lilia M; Koval, Stella V; Rodionova, Nataliia K; Zavelevich, Michael P; Ivanivskaya, Tetiana S; Poludnenko, Liudmyla Yu; Ukrainskaya, Nataliia I

    2015-10-01

    The studies of the recent decades posed the question of the association between radiation exposure and myelodysplastic syndromes (MDS). This association has been proved in secondary MDS originating upon exposure to chemotherapeutics and/or radiation therapy. The long-term study in Japanese atomic (A)-bomb survivors demonstrated the significant linear dose-response for MDS confirming the link between radiation exposure and this form of hematopoietic malignancies. All these findings provide the strong basis for studying MDS in the persons exposed to radiation following the Chernobyl disaster, especially those in the cohort of Chernobyl clean-up workers of 1986-1987. The data on MDS among Chernobyl clean-up workers (1986-1987) diagnosed in 1996-2012 at the reference laboratory of RE Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology are summarized. MDS cases were diagnosed in 23 persons (21 males and 2 females) having been exposed to radiation as clean-up workers of 1986-1987. Refractory anemia (RA) has been detected in 13, refractory anemia with ring sideroblasts (RARS)-in 2, and refractory anemia with excess blasts (RAEB)-in 8 patients. The median age of those MDS patients was 62.0 years. In addition, 5 cases of chronic myelomonocytic leukemia (CMML) were recorded in the group of Chernobyl clean-up workers with the median time of 14.8 years from 1986-1987 to diagnosis. The association between radiation exposure and MDS is discussed. The suggested life-long risk for myelodysplastic syndromes among A-bomb survivors in Japan highlights the importance of the continuing follow-up studies in the affected populations in the post-Chernobyl period.

  14. 40 CFR 263.31 - Discharge clean up.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 27 2013-07-01 2013-07-01 false Discharge clean up. 263.31 Section 263...) STANDARDS APPLICABLE TO TRANSPORTERS OF HAZARDOUS WASTE Hazardous Waste Discharges § 263.31 Discharge clean up. A transporter must clean up any hazardous waste discharge that occurs during transportation...

  15. 40 CFR 263.31 - Discharge clean up.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 26 2014-07-01 2014-07-01 false Discharge clean up. 263.31 Section 263...) STANDARDS APPLICABLE TO TRANSPORTERS OF HAZARDOUS WASTE Hazardous Waste Discharges § 263.31 Discharge clean up. A transporter must clean up any hazardous waste discharge that occurs during transportation...

  16. 40 CFR 263.31 - Discharge clean up.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 27 2012-07-01 2012-07-01 false Discharge clean up. 263.31 Section 263...) STANDARDS APPLICABLE TO TRANSPORTERS OF HAZARDOUS WASTE Hazardous Waste Discharges § 263.31 Discharge clean up. A transporter must clean up any hazardous waste discharge that occurs during transportation...

  17. 40 CFR 263.31 - Discharge clean up.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 26 2011-07-01 2011-07-01 false Discharge clean up. 263.31 Section 263...) STANDARDS APPLICABLE TO TRANSPORTERS OF HAZARDOUS WASTE Hazardous Waste Discharges § 263.31 Discharge clean up. A transporter must clean up any hazardous waste discharge that occurs during transportation...

  18. 40 CFR 263.31 - Discharge clean up.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Discharge clean up. 263.31 Section 263...) STANDARDS APPLICABLE TO TRANSPORTERS OF HAZARDOUS WASTE Hazardous Waste Discharges § 263.31 Discharge clean up. A transporter must clean up any hazardous waste discharge that occurs during transportation...

  19. 48 CFR 52.236-12 - Cleaning Up.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 2 2012-10-01 2012-10-01 false Cleaning Up. 52.236-12 Section 52.236-12 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION (CONTINUED... Cleaning Up. As prescribed in 36.512, insert the following clause: Cleaning Up (APR 1984) The...

  20. 48 CFR 52.236-12 - Cleaning Up.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 2 2013-10-01 2013-10-01 false Cleaning Up. 52.236-12 Section 52.236-12 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION (CONTINUED... Cleaning Up. As prescribed in 36.512, insert the following clause: Cleaning Up (APR 1984) The...

  1. 48 CFR 52.236-12 - Cleaning Up.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 2 2014-10-01 2014-10-01 false Cleaning Up. 52.236-12 Section 52.236-12 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION (CONTINUED... Cleaning Up. As prescribed in 36.512, insert the following clause: Cleaning Up (APR 1984) The...

  2. 48 CFR 52.236-12 - Cleaning Up.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Cleaning Up. 52.236-12 Section 52.236-12 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION (CONTINUED... Cleaning Up. As prescribed in 36.512, insert the following clause: Cleaning Up (APR 1984) The...

  3. 48 CFR 52.236-12 - Cleaning Up.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 2 2011-10-01 2011-10-01 false Cleaning Up. 52.236-12 Section 52.236-12 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION (CONTINUED... Cleaning Up. As prescribed in 36.512, insert the following clause: Cleaning Up (APR 1984) The...

  4. Dioxin and polychlorinated biphenyl analysis: automation and improvement of clean-up established by example of spices.

    PubMed

    Kleinhenz, Silvia; Jira, Wolfgang; Schwind, Karl-Heinz

    2006-04-01

    To analyze polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDDs/PCDFs) and polychlorinated biphenyls (PCBs) in spices by gas chromatography-mass spectrometry, a new clean-up method had to be developed owing to the high content of essential oils in the samples. A solid-phase extraction (SPE) column with activated silica endowed with sulfuric acid and sodium hydroxide was used. Under these conditions, clean-up was achieved using at least 5-7 g of pepper and even higher amounts of other spices. The automatized clean-up comprised three additional chromatographic steps after accelerated solvent extraction (ASE) followed by gel permeation: chromatography on a florisil SPE column, extract cleaning with the above-mentioned silica SPE column and chromatography with an activated charcoal column. On the basis of this automatized clean-up, a method that is more effective, rapid, simplified and economical than the available methods for PCDD/PCDF and PCB analysis is proposed. In model studies, the average recoveries for PCDDs/PCDFs ranged between 82.6% and 105.6% and for the PCBs between 71.3% and 113.3%.

  5. Cockroaches probably cleaned up after dinosaurs.

    PubMed

    Vršanský, Peter; van de Kamp, Thomas; Azar, Dany; Prokin, Alexander; Vidlička, L'ubomír; Vagovič, Patrik

    2013-01-01

    Dinosaurs undoubtedly produced huge quantities of excrements. But who cleaned up after them? Dung beetles and flies with rapid development were rare during most of the Mesozoic. Candidates for these duties are extinct cockroaches (Blattulidae), whose temporal range is associated with herbivorous dinosaurs. An opportunity to test this hypothesis arises from coprolites to some extent extruded from an immature cockroach preserved in the amber of Lebanon, studied using synchrotron X-ray microtomography. 1.06% of their volume is filled by particles of wood with smooth edges, in which size distribution directly supports their external pre-digestion. Because fungal pre-processing can be excluded based on the presence of large particles (combined with small total amount of wood) and absence of damages on wood, the likely source of wood are herbivore feces. Smaller particles were broken down biochemically in the cockroach hind gut, which indicates that the recent lignin-decomposing termite and cockroach endosymbionts might have been transferred to the cockroach gut upon feeding on dinosaur feces.

  6. Helping nature clean up oil spills

    SciTech Connect

    Paddock, A.

    1996-11-01

    Oil spills are nothing new. In fact, for millions of years crude oil has been seeping up to the Earth`s surface, and for all that time Mother Nature has been on the job with microbes, or bacteria, to harmlessly convert the oil to water and carbon dioxide gas. Not all bacteria are bad. True, some can make us sick, however, the good ones help us bake bread, brew beer, and even clean up oil spills by a process known as biodegradation. Oil and bacteria don`t easily get together because oil and water don`t mix and bacteria prefer to stay in water. After some oil tankers spills in the English Channel 25 years ago, major oil companies (Arco, BP, Exxon, and others) developed oil dispersant products-specialized chemicals that make oils and sea water mix. The simplest examples of similar wetting agents are soaps and detergents. Now, thanks to dispersants, the natural bacteria at sea can easily get to the oil and the normally slow biodegradation process goes rather quickly.

  7. Cockroaches Probably Cleaned Up after Dinosaurs

    PubMed Central

    Vršanský, Peter; van de Kamp, Thomas; Azar, Dany; Prokin, Alexander; Vidlička, L'ubomír; Vagovič, Patrik

    2013-01-01

    Dinosaurs undoubtedly produced huge quantities of excrements. But who cleaned up after them? Dung beetles and flies with rapid development were rare during most of the Mesozoic. Candidates for these duties are extinct cockroaches (Blattulidae), whose temporal range is associated with herbivorous dinosaurs. An opportunity to test this hypothesis arises from coprolites to some extent extruded from an immature cockroach preserved in the amber of Lebanon, studied using synchrotron X-ray microtomography. 1.06% of their volume is filled by particles of wood with smooth edges, in which size distribution directly supports their external pre-digestion. Because fungal pre-processing can be excluded based on the presence of large particles (combined with small total amount of wood) and absence of damages on wood, the likely source of wood are herbivore feces. Smaller particles were broken down biochemically in the cockroach hind gut, which indicates that the recent lignin-decomposing termite and cockroach endosymbionts might have been transferred to the cockroach gut upon feeding on dinosaur feces. PMID:24324610

  8. Tidd hot gas clean up program. Final report

    SciTech Connect

    1995-10-01

    This Final Report on the Tidd Hot Gas Clean Up Program covers the period from initial Proof-of-Concept testing in August, 1990, through final equipment inspections in May, 1995. The Tidd Hot Gas Clean Up (HGCU) system was installed in the Tidd Pressurized Fluidized Bed Combustion (PFBC) Demonstration Plant, which is the first utility-scale PFBC plant in the United States. Detailed design work on the project began in July, 1990, and site construction began in December, 1991. Initial operation of the system occurred in May, 1992, and the hot gas filter was commissioned in October, 1992. The test program ended in March, 1995, when the Tidd Plant was shut down following its four-year test program. Section 1.0 of this report is an executive summary of the project covering the project background, system description, test results and conclusions. Section 2.0 is an introduction covering the program objectives and schedule. Section 3.0 provides detailed descriptions of the system and its major components. Section 4.0 provides detailed results of all testing including observations and posttest inspection results. Sections 5.0 and 6.0 list the program conclusions and recommendations, respectively. Appendix I is a report prepared by Southern Research Institute on the properties of Tidd PFBC ash sampled during the test program. Appendix II is a report prepared by Westinghouse STC on the performance of candle filter fail-safe regenerator devices.

  9. Clean-up criteria for remediation of contaminated soils

    SciTech Connect

    Nguyen, H.D.; Wilson, J.R.; Sato, Chikashi

    1997-08-01

    {open_quotes}How clean is clean?{close_quotes} is a question commonly raised in the remediation of contaminated soils. To help with the answer, criteria are proposed to serve as guidelines for remedial actions and to define a clean-up level such that the remaining contaminant residuals in the soil will not violate the Drinking Water Standards (DWS). The equations for computing those criteria are developed from the principle of conservation of mass and are functions of the maximum concentration level in the water (MCL) and the sorption coefficient. A multiplier, ranging from 10 to 1000, is also factored into the soil standard equation to reflect the effectiveness of various remediation techniques. Maximum allowable concentration in the soil (MSCL) is presented for several contaminants which are being regulated at the present time. Future modifications are recommended for better estimates of the MSCLs as additional transport mechanisms are incorporated to account for other potentially dominant effects.

  10. Tephra fall clean-up in urban environments

    NASA Astrophysics Data System (ADS)

    Hayes, Josh L.; Wilson, Thomas M.; Magill, Christina

    2015-10-01

    Tephra falls impact urban communities by disrupting transport systems, contaminating and damaging buildings and infrastructures, and are potentially hazardous to human health. Therefore, prompt and effective tephra clean-up measures are an essential component of an urban community's response to tephra fall. This paper reviews case studies of tephra clean-up operations in urban environments around the world, spanning 50 years. It identifies methods used in tephra clean-up and assesses a range of empirical relationships between level of tephra accumulation and clean-up metrics such as collected tephra volume, costs, and duration of operations. Results indicate the volume of tephra collected from urban areas is proportional to tephra accumulation. Urban areas with small tephra accumulations (1,000 m3/km2 or an average of 1 mm thickness) may collect < 1% of the total deposit, whereas urban areas which experience large accumulations (> 50,000 m3/km2 or an average of 50 mm thickness) remove up to 80%. This relationship can inform impact and risk assessments by providing an estimate of the likely response required for a given tephra fall. No strong relationship was found between tephra fall accumulation and clean-up cost or duration for urban environments which received one-off tephra falls, suggesting that these aspects of tephra fall clean-up operations are context specific. Importantly, this study highlights the advantage of effective planning for tephra clean-up and disposal in potentially exposed areas.

  11. Automation of a clean-up procedure for determination of trichothecenes in cereals using a charcoal-alumina column.

    PubMed

    Langseth, W; Clasen, P E

    1992-06-19

    Automation of the clean-up procedure for trichothecenes on a charcoal-alumina column is described. Standard high-performance liquid chromatographic equipment was used for the clean-up step. An acetonitrile-water (84 + 16, v/v) extract of the sample was cleaned up on a column packed with charcoal-alumina-Celite, which was washed with acetonitrile between each sample. The eluates were collected directly in reaction vials and evaporated to dryness. The residual water was removed azeotropically with benzene. The sample was derivatized with 1-(trimethylsilyl)imidazole and analysed by capillary gas chromatography with electron-capture detection.

  12. 36. HISTORIC PHOTOGRAPH SHOWING BILL KEYS CLEANING UP AFTER THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    36. HISTORIC PHOTOGRAPH SHOWING BILL KEYS CLEANING UP AFTER THE MILL RUN (NOTE SCREEN FROM MORTAR SETTING ON TABLE, STAMPS ARE HUNG UP). - Wall Street Gold Mill, Twentynine Palms, San Bernardino County, CA

  13. PCR inhibitor removal using the NucleoSpin® DNA Clean-Up XS kit.

    PubMed

    Faber, Korie L; Person, Eric C; Hudlow, William R

    2013-01-01

    Forensic evidence samples are collected from an unlimited variety of substrates, which may contain compounds known to inhibit the polymerase chain reaction (PCR). These PCR inhibitors are co-extracted with the DNA sample and can negatively affect the DNA typing results, which can range from partial to complete inhibition of the short tandem repeat (STR) PCR. One potential solution is to remove the PCR inhibitors from the extracts prior to the STR PCR with the NucleoSpin(®) DNA Clean-Up XS kit. The kit contains a NucleoSpin(®) XS silica column that has a special funnel design of thrust rings along with a very small silica membrane, which allows for sample elution in a small volume that is appropriate for use with current STR typing kits. The NucleoSpin(®) DNA Clean-Up XS kit was optimized for the best possible DNA recovery and then evaluated for its ability to remove eight commonly encountered PCR inhibitors including: bile salt, collagen, hematin, humic acid, indigo, melanin, tannic acid and urea. Each of these PCR inhibitors was effectively removed by the NucleoSpin(®) DNA Clean-Up XS kit as demonstrated by generating more complete STR profiles from the cleaned up inhibitor samples than from the raw inhibitor samples.

  14. High-throughput method of dioxin analysis in aqueous samples using consecutive solid phase extraction steps with the new C18 Ultraflow™ pressurized liquid extraction and automated clean-up.

    PubMed

    Youn, Yeu-Young; Park, Deok Hie; Lee, Yeon Hwa; Lim, Young Hee; Cho, Hye Sung

    2015-01-01

    A high-throughput analytical method has been developed for the determination of seventeen 2,3,7,8-substituted congeners of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in aqueous samples. A recently introduced octadecyl (C18) disk for semi-automated solid-phase extraction of PCDD/Fs in water samples with a high level of particulate material has been tested for the analysis of dioxins. A new type of C18 disk specially designed for the analysis of hexane extractable material (HEM), but never previously reported for use in PCDD/Fs analysis. This kind of disk allows a higher filtration flow, and therefore the time of analysis is reduced. The solid-phase extraction technique is used to change samples from liquid to solid, and therefore pressurized liquid extraction (PLE) can be used in the pre-treatment. In order to achieve efficient purification, extracts from the PLE are purified using an automated Power-prep system with disposable silica, alumina, and carbon columns. Quantitative analyses of PCDD/Fs were performed by GC-HRMS using multi-ion detection (MID) mode. The method was successfully applied to the analysis of water samples from the wastewater treatment system of a vinyl chloride monomer plant. The entire procedure is in agreement with EPA1613 recommendations regarding the blank control, MDLs (method detection limits), accuracy, and precision. The high-throughput method not only meets the requirements of international standards, but also shortens the required analysis time from 2 weeks to 3d.

  15. Determination of trace Cd, Cu, Fe, Pb and Zn in diesel and gasoline by inductively coupled plasma mass spectrometry after sample clean up with hollow fiber solid phase microextraction system

    NASA Astrophysics Data System (ADS)

    Nomngongo, Philiswa N.; Ngila, J. Catherine

    2014-08-01

    This study reports a simple and efficient method for the determination of trace Cd, Cu, Fe, Pb and Zn in diesel and gasoline samples by inductively coupled plasma mass spectrometry after matrix removal and analyte pre-concentration using hollow fiber-solid phase microextraction (HF-SPME). The optimization of HF-SPME procedure was carried out using two-level full factorial and central composite designs. Four factors (variables), that are, sample solution pH, acceptor phase amount, extraction time and eluent concentration were optimized. Under the optimized experimental conditions, the precision was ≤ 3% (C = 10 μg L- 1, n = 15), limits of detection and quantification ranged from 0.1 to 0.3 μg L- 1 and 0.3-0.9 μg L- 1, respectively, and the maximum preconcentration factor was 30. The HF-SPME method was applied for the determination of trace metals in real gasoline and diesel samples.

  16. On-line coupling of sequential injection extraction with restricted-access materials and post-column derivatization for sample clean-up and determination of propranolol in human plasma.

    PubMed

    Satínský, Dalibor; Serralheiro, Hugo S; Solich, Petr; Araújo, Alberto N; Montenegro, Maria C B S M

    2007-09-26

    The presented paper deals with a new methodology for direct determination of propranolol in human plasma. The methodology described is based on sequential injection analysis technique (SIA) coupled with solid phase extraction (SPE) column based on restricted access materials (RAM). Special RAM column containing 30 microm polymeric material-N-vinylacetamide copolymer was integrated into the sequential injection manifold. SIA-RAM system was used for selective retention of propranolol, while the plasma matrix components were eluted with two weak organic solutions to waste. Due to the acid-basic and polarity properties of propranolol molecule and principles of reversed-phase chromatography, it was possible to retain propranolol on the N-vinylacetamide copolymer sorbent (Shodex MSpak PK-2A 30 microm (2 mm x 10 mm)). Centrifuged plasma samples were aspirated into the system and loaded onto the column using acetonitrile-water (5:95, v/v), pH 11.00, adjusted by triethylamine. The analyte was retained on the column while proteins contained in the sample were removed to waste. Interfering endogenous substances complicating detection were washed out by acetonitrile-water (15:85), pH 11.00 in the next step. The extracted analyte was eluted by means of tetrahydrofuran-water (25:75), pH 11.00 to the fluorescence detector (emission filter 385 nm). The whole procedure comprising sample pre-treatment, analyte detection and column reconditioning took about 15 min. The recoveries of propranolol from undiluted plasma were in the range 96.2-97.8% for three concentration levels of analyte. The proposed SIA-RAM method has been applied for direct determination of propranolol in human plasma.

  17. Kinetics of combined SO/sub 2//NO in flue gas clean-up

    SciTech Connect

    Chang, S.G.; Littlejohn, D.

    1985-03-01

    The kinetics of reactions involving SO/sub 2/, NO, and ferrous chelate additives in wet flue gas simultaneous desulfurization and denitrification scrubbers are discussed. The relative importance of these reactions are assessed. The relevance of these reactions to spray dryer processes for combined SO/sub 2//NO flue gas clean-up is addressed. 37 refs., 7 figs.

  18. Capillary-Channeled Polymer (C-CP) Fibers as a Stationary Phase for Sample Clean-Up of Protein Solutions for Matrix-Assisted Laser/Desorption Ionization Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Manard, Benjamin T.; Marcus, R. Kenneth

    2012-08-01

    Capillary-channeled polymer (C-CP) fibers are employed in a micropipette tip format to affect a stationary phase for the solid phase extraction (SPE) of proteins from buffer solutions prior to MALDI-MS analysis. Proteins readily adsorb to the polypropylene (PP) C-CP fibers while buffer species are easily washed off the tips using DI-H2O. Elution of the solutes is achieved with an aliquot of 50:50 ACN:H2O, which is compatible with the subsequent spotting on the MALDI target with the matrix solution. Lysozyme and cytochrome c are used as test species, with a primary buffer composition of 100 mM Tris-HCl. In this case, direct MALDI-MS produces no discernible protein signals. SPE on the C-CP fibers yields high fidelity mass spectra for 1 μL sample volumes. Limits of detection for cytochrome c in 100 mM Tris-HCl are on the order of 40 nM. Extraction of cytochrome c from buffer concentrations of up to 1 M Tris-HCl, provides signal recoveries that are suppressed by only ~50 % versus neat protein solutions. Finally, extraction of 3.1 μM cytochrome c from a synthetic urine matrix exhibits excellent recovery.

  19. PRP: The Proven Solution for Cleaning Up Oil Spills

    NASA Technical Reports Server (NTRS)

    2006-01-01

    The basic technology behind PRP is thousands of microcapsules, tiny balls of beeswax with hollow centers. Water cannot penetrate the microcapsule s cell, but oil is absorbed right into the beeswax spheres as they float on the water s surface. This way, the contaminants, chemical compounds that originally come from crude oil such as fuels, motor oils, or petroleum hydrocarbons, are caught before they settle. PRP works well as a loose powder for cleaning up contaminants in lakes and other ecologically fragile areas. The powder can be spread over a contaminated body of water or soil, and it will absorb contaminants, contain them in isolation, and dispose of them safely. In water, it is important that PRP floats and keeps the oil on the surface, because, even if oil exposure is not immediately lethal, it can cause long-term harm if allowed to settle. Bottom-dwelling fish exposed to compounds released after oil spills may develop liver disease, in addition to reproductive and growth problems. This use of PRP is especially effective for environmental cleanup in sensitive areas like coral reefs and mangroves.

  20. Mt. Dioxin: "Clean Up" Action Threatens Florida Community.

    ERIC Educational Resources Information Center

    Gibbs, Lois

    1995-01-01

    Addresses citizen action taken by African American communities in Pensacola, Florida located in close proximity to a Superfund site. Discusses how the community is organizing to stop site clean-up efforts that residents claim have unjustly increased their already high exposure to toxins such as dioxin. (LZ)

  1. Marine Debris Clean-Ups as Meaningful Science Learning

    ERIC Educational Resources Information Center

    Stepath, Carl M.; Bacon, Joseph Scott

    2010-01-01

    This seven to eight week hands-on Marine Debris Clean-up Project used a service project to provide an introduction of marine science ecology, watershed interrelationships, the scientific method, and environmental stewardship to 8th grade middle school students. It utilized inquiry based learning to introduce marine debris sources and impacts to…

  2. Coupling detergent lysis/clean-up methodology with intact protein fractionation for enhanced proteome characterization

    SciTech Connect

    Sharma, Ritin; Dill, Brian; Chourey, Karuna; Shah, Manesh B; Verberkmoes, Nathan C; Hettich, Robert {Bob} L

    2012-01-01

    The expanding use of surfactants for proteome sample preparations has prompted the need to systematically optimize the application and removal of these MS-deleterious agents prior to proteome measurements. Here we compare four different detergent clean-up methods (Trichloroacetic acid (TCA) precipitation, Chloroform/Methanol/Water (CMW) extraction, commercial detergent removal spin column method (DRS) and filter-aided sample preparation(FASP)) with respect to varying amounts of protein biomass in the samples, and provide efficiency benchmarks with respect to protein, peptide, and spectral identifications for each method. Our results show that for protein limited samples, FASP outperforms the other three clean-up methods, while at high protein amount all the methods are comparable. This information was used in a dual strategy of comparing molecular weight based fractionated and unfractionated lysates from three increasingly complex samples (Escherichia coli, a five microbial isolate mixture, and a natural microbial community groundwater sample), which were all lysed with SDS and cleaned up using FASP. The two approaches complemented each other by enhancing the number of protein identifications by 8%-25% across the three samples and provided broad pathway coverage.

  3. Analysis of fusaric acid in maize using molecularly imprinted solid phase extraction (MISPE) clean-up and ion-pair LC with diode array UV detection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusaric acid is a phytotoxin and mycotoxin occasionally found in maize contaminated with Fusarium fungi. A selective sample clean-up procedure was developed to detect fusaric acid in maize using molecularly imprinted solid phase extraction (MISPE) clean-up coupled with ion-pair liquid chromatography...

  4. Groundwater clean-up: The Savannah River Site experience

    SciTech Connect

    Horvath, J.G.; Surovchak, S.R.

    1991-12-31

    Protection of the Earth`s valuable resources is of great concern to the public in relation to safety and health. One of the resources receiving extensive attention is groundwater. Past waste disposal practices have impacted groundwater quality in many locations throughout the nation. In response, the Federal Government has passed legislation to protect and restore the environment. In many cases, application of this legislation has lead to strict clean-up standards. Savannah River Site (SRS) experiences suggest that meeting clean-up standards is a challenge in light of technical realities. The purpose of this paper is to describe the corrective action program that is addressing a plume of volatile organics beneath the A/M Area of the SRS. The history and status of the program, costs, measures of performance, lessons learned, and challenges faced are presented.

  5. Groundwater clean-up: The Savannah River Site experience

    SciTech Connect

    Horvath, J.G. ); Surovchak, S.R. )

    1991-01-01

    Protection of the Earth's valuable resources is of great concern to the public in relation to safety and health. One of the resources receiving extensive attention is groundwater. Past waste disposal practices have impacted groundwater quality in many locations throughout the nation. In response, the Federal Government has passed legislation to protect and restore the environment. In many cases, application of this legislation has lead to strict clean-up standards. Savannah River Site (SRS) experiences suggest that meeting clean-up standards is a challenge in light of technical realities. The purpose of this paper is to describe the corrective action program that is addressing a plume of volatile organics beneath the A/M Area of the SRS. The history and status of the program, costs, measures of performance, lessons learned, and challenges faced are presented.

  6. Improved clean-up for the determination of lasalocid in 'difficult' food matrices.

    PubMed

    Tarbin, J A; Rawlings, E; Tyler, D; Sharman, M

    2002-01-01

    Methodology has been developed for the determination of lasalocid in analytically 'difficult' matrices such as processed and spiced foods. The procedure was based on an existing silica-based solid-phase extraction (SPE) clean-up to which was added a novel NH2 SPE step before HPLC with fluorescence detection. Use of the additional step enabled the determination of lasalocid in matrices such as baby food, meat pies ('pasties'), etc. Analysis of these matrices was not possible using the standard clean-up on its own. Chromatography showed a massive reduction in the amount of co-extractives and interferences. Validation data were obtained down to the 10-40 mg kg(-1) level for a range of products. Recoveries ranged from 74% at 10 microg kg(-1) for pork sausages to 96% at 40 microg kg(-1) for meat pies. PMID:11817373

  7. Comparison of Clean-Up Methods for Ochratoxin A on Wine, Beer, Roasted Coffee and Chili Commercialized in Italy

    PubMed Central

    Prelle, Ambra; Spadaro, Davide; Denca, Aleksandra; Garibaldi, Angelo; Gullino, Maria Lodovica

    2013-01-01

    The most common technique used to detect ochratoxin A (OTA) in food matrices is based on extraction, clean-up, and chromatography detection. Different clean-up cartridges, such as immunoaffinity columns (IAC), molecular imprinting polymers (MIP), Mycosep™ 229, Mycospin™, and Oasis® HLB (Hydrophilic Lipophilic balance) as solid phase extraction were tested to optimize the purification for red wine, beer, roasted coffee and chili. Recovery, reproducibility, reproducibility, limit of detection (LOD) and limit of quantification (LOQ) were calculated for each clean-up method. IAC demonstrated to be suitable for OTA analysis in wine and beer with recovery rate >90%, as well as Mycosep™ for wine and chili. On the contrary, MIP columns were the most appropriate to clean up coffee. A total of 120 samples (30 wines, 30 beers, 30 roasted coffee, 30 chili) marketed in Italy were analyzed, by applying the developed clean-up methods. Twenty-seven out of 120 samples analyzed (22.7%: two wines, five beers, eight coffees, and 12 chili) resulted positive to OTA. A higher incidence of OTA was found in chili (40.0%) more than wine (6.6%), beers (16.6%) and coffee (26.6%). Moreover, OTA concentration in chili was the highest detected, reaching 47.8 µg/kg. Furthermore, three samples (2.5%), two wines and one chili, exceeded the European threshold. PMID:24152987

  8. Comparison of clean-up methods for ochratoxin A on wine, beer, roasted coffee and chili commercialized in Italy.

    PubMed

    Prelle, Ambra; Spadaro, Davide; Denca, Aleksandra; Garibaldi, Angelo; Gullino, Maria Lodovica

    2013-10-01

    The most common technique used to detect ochratoxin A (OTA) in food matrices is based on extraction, clean-up, and chromatography detection. Different clean-up cartridges, such as immunoaffinity columns (IAC), molecular imprinting polymers (MIP), Mycosep™ 229, Mycospin™, and Oasis® HLB (Hydrophilic Lipophilic balance) as solid phase extraction were tested to optimize the purification for red wine, beer, roasted coffee and chili. Recovery, reproducibility, reproducibility, limit of detection (LOD) and limit of quantification (LOQ) were calculated for each clean-up method. IAC demonstrated to be suitable for OTA analysis in wine and beer with recovery rate >90%, as well as Mycosep™ for wine and chili. On the contrary, MIP columns were the most appropriate to clean up coffee. A total of 120 samples (30 wines, 30 beers, 30 roasted coffee, 30 chili) marketed in Italy were analyzed, by applying the developed clean-up methods. Twenty-seven out of 120 samples analyzed (22.7%: two wines, five beers, eight coffees, and 12 chili) resulted positive to OTA. A higher incidence of OTA was found in chili (40.0%) more than wine (6.6%), beers (16.6%) and coffee (26.6%). Moreover, OTA concentration in chili was the highest detected, reaching 47.8 µg/kg. Furthermore, three samples (2.5%), two wines and one chili, exceeded the European threshold. PMID:24152987

  9. Comparison of clean-up methods for ochratoxin A on wine, beer, roasted coffee and chili commercialized in Italy.

    PubMed

    Prelle, Ambra; Spadaro, Davide; Denca, Aleksandra; Garibaldi, Angelo; Gullino, Maria Lodovica

    2013-10-22

    The most common technique used to detect ochratoxin A (OTA) in food matrices is based on extraction, clean-up, and chromatography detection. Different clean-up cartridges, such as immunoaffinity columns (IAC), molecular imprinting polymers (MIP), Mycosep™ 229, Mycospin™, and Oasis® HLB (Hydrophilic Lipophilic balance) as solid phase extraction were tested to optimize the purification for red wine, beer, roasted coffee and chili. Recovery, reproducibility, reproducibility, limit of detection (LOD) and limit of quantification (LOQ) were calculated for each clean-up method. IAC demonstrated to be suitable for OTA analysis in wine and beer with recovery rate >90%, as well as Mycosep™ for wine and chili. On the contrary, MIP columns were the most appropriate to clean up coffee. A total of 120 samples (30 wines, 30 beers, 30 roasted coffee, 30 chili) marketed in Italy were analyzed, by applying the developed clean-up methods. Twenty-seven out of 120 samples analyzed (22.7%: two wines, five beers, eight coffees, and 12 chili) resulted positive to OTA. A higher incidence of OTA was found in chili (40.0%) more than wine (6.6%), beers (16.6%) and coffee (26.6%). Moreover, OTA concentration in chili was the highest detected, reaching 47.8 µg/kg. Furthermore, three samples (2.5%), two wines and one chili, exceeded the European threshold.

  10. An alternative clean-up column for the determination of polychlorinated biphenyls in solid matrices.

    PubMed

    Ndunda, Elizabeth N; Madadi, Vincent O; Mizaikoff, Boris

    2015-12-01

    The need for continuous monitoring of polychlorinated biphenyls (PCBs) has necessitated the development of analytical techniques that are sensitive and selective with minimal reagent requirement. In light of this, we developed a column for clean-up of soil and sediment extracts, which is less demanding in terms of the amount of solvent and sorbent. The dual-layer column consists of acidified silica gel and molecularly imprinted polymers (MIPs). MIPs were synthesized via aqueous suspension polymerization using PCB 15 as the dummy template, 4-vinylpyridine as the functional monomer and ethylene glycol dimethacrylate as the cross-linker and the obtained particles characterized via SEM, BET, and batch rebinding assays. Pre-concentration of the spiked real-world water sample using MISPE gave recoveries between 85.2 and 104.4% (RSD < 8.69). On the other hand, the specific dual-layer column designed for clean-up of extracts from complex matrices provided recoveries of 91.6-102.5% (RSD < 4%) for spiked soil, which was comparable to clean-up using acidified silica (70.4-90.5%; RSD < 3.72%) and sulfoxide modified silica (89.7-103.0%; RSD < 13.0%). However, the polymers were reusable maintaining recoveries of 79.8-111.8% after 30 cycles of regeneration and re-use, thereby availing a cost-effective clean-up procedure for continuous monitoring of PCBs. Method detection limits were 0.01-0.08 ng g(-1) and 0.002-0.01 ng mL(-1) for solid matrices and water, respectively.

  11. Determination of pesticide residues in fish tissues by modified QuEChERS method and dual-d-SPE clean-up coupled to gas chromatography-mass spectrometry.

    PubMed

    Molina-Ruiz, Juan Manuel; Cieslik, Ewa; Cieslik, Iwona; Walkowska, Izabela

    2015-01-01

    The aim of this research was to modify the Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method for the determination of organochlorine and organophosphate pesticides in fatty animal matrices such as fish muscle tissues of carp and sturgeon collected from Carp Valley, Lesser Poland. Pesticides extraction effectiveness was evaluated at 0.030 mg kg(-1) spiking level and efficiency of the dispersive-solid-phase extraction (d-SPE) clean-up step was evaluated by comparison testing two different d-SPE clean-up stages, first the addition of the d-SPE sorbent combination (PSA + SAX + NH2), and secondly the addition of C18 after extracts enrichment with the d-SPE sorbent combination (PSA + SAX + NH2), introducing a novel concept of clean-up named dual-d-SPE clean-up. Analysis of pesticide residues was performed by Gas Chromatography Quadrupole Mass Spectrometry (GC/Q-MS) working in selected-ion monitoring (SIM) mode. Linear relation was observed from 0 to 200 ng mL(-1) and determination coefficient R(2) > 0.997 in all instances for all target analytes. Better recoveries and cleanliness of extracts in both samples, carp and sturgeon tissues, were obtained after C18 addition during the dual-d-SPE clean-up step. Recoveries were in the range 70-120%, with relative standard deviation lower than 10% at 0.030 mg kg(-1) spiking level for most pesticides. LODs ranged 0.001-0.003 mg kg(-1), while LOQs ranged 0.004-0.009 mg kg(-1). The proposed method was successfully applied analyzing pesticide residues in real carp and sturgeon muscle samples; detectable pesticide residues were observed, but in all of the cases contamination level was lower than the default maximum residue levels (MRLs) set by the European Union (EU), Regulation (EC) N 396/2005.

  12. Interim Site Assessment and Clean-up Guidebook

    SciTech Connect

    Elliott, K.L.

    1996-12-31

    In April 1995 an Interim Site Investigation and Clean-up Guidebook (for petroleum hydrocarbon and volatile organic compound impacted sites) was developed for public use. The purpose of the Guidebook was to offer a new approach to the site cleanup process: one that reduces time, cuts costs, and establishes a defined endpoint for investigations and cleanup actions. The Guidebook provided a matrix to screen for low-risk contaminated sites. After a year of use, the Guidebook was revised in May 1996. The most notable change was in the Petroleum Hydrocarbon Section and the modification of the screening table for petroleum hydrocarbon contaminated sites. The changes considered the strong influence of lithology on contaminant transport and recognized the large attenuation of the long chain, heavy oil and tar, hydrocarbons in soils.

  13. Cleaning up the nuclear weapons complex: A herculean challenge

    SciTech Connect

    Probst, K.N.; McGovern, M.H.

    1996-12-31

    For nearly five decades, the US Department of Energy (DOE) and its predecessors engaged in a highly secretive, complex, and massive endeavor to fabricate nuclear weapons for national security purposes. Large-scale production of nuclear weapons was an unprecedented undertaking requiring thousands of facilities, dozens of large tracts of land, huge volumes of dangerous materials, and great quantities of water. With the Cold Wars end and the emergence of new types of national security concerns, weapons production operations have, for the most part, ceased, and much of the secrecy under which they were shrouded has lifted. The subsequent revelation reveal at many sites tremendous volumes of soil and groundwater are contaminated with both radioactive and hazardous materials. Wastes stored for years pose substantial dangers, and many aging facilities that harbor highly radioactive and sensitive materials are deteriorating. The topics covered in this overview article include the following: more to `cleanup` than cleaning up; a fragmented regulatory regime; new regulatory regimes.

  14. Hudson River PCB clean-up to begin

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    U.S. Environmental Protection Agency Administrator Christie Whitman signed the Record of Decision on 1 February to clean up a stretch of the Hudson River that has been contaminated by polychlorinated biphenyls (PCBs). The decision calls for dredging 2 million cubic meters of PCB-contaminated sediment from a 64-kilometer stretch of the upper Hudson to remove about 68,000 kilograms of PCBs.The plan follows years of scientific study about whether the PCBs were safely encased in the sediment or posed a continuing hazard, and concern over whether the PCBs can be safely removed without stirring up a larger pollution problem along the river. The EPA found that PCBs in the sediment are not safely buried because erosion and river flows can redistribute river sediment. The agency also found that although PCBs break down naturally over time, this degradation does not render them harmless.

  15. Recent trends at the state and federal level in accelerating CERCLA clean-ups

    SciTech Connect

    Clegg, B.

    1996-12-31

    Efforts at accelerating remedial action at the federal level focus on the following: the Superfund accelerated clean-up model (SCAM); Brownfields economic redevelopment initiative; guidance documents and policies; and collaboration with state voluntary cleanup programs. At the state level efforts involved in accelerating clean-ups include voluntary clean-up programs and Brownfields initiatives.

  16. Capacity of the bioremediation technology for clean-up of soil and groundwater contaminated with petroleum hydrocarbons.

    PubMed

    Masak, Jan; Machackova, Jirina; Siglova, Martina; Cejkova, Alena; Jirku, Vladimir

    2003-01-01

    A column reactor was designed and used to simulate conditions affecting the bioremediations of petroleum hydrocarbons. The work illustratively describes the aerobic (model) clean-up of soil samples enabling to predict the efficiency of a technology installed in parallel on contaminated former airport. The data showing the performance of thus precharacterized technology are presented.

  17. Next steps in the development of ecological soil clean-up values for metals.

    PubMed

    Wentsel, Randall; Fairbrother, Anne

    2014-07-01

    This special series in Integrated Environmental Assessment Management presents the results from 6 workgroups that were formed at the workshop on Ecological Soil Levels-Next Steps in the Development of Metal Clean-Up Values (17-21 September 2012, Sundance, Utah). This introductory article presents an overview of the issues assessors face when conducting risk assessments for metals in soils, key US Environmental Protection Agency (USEPA) documents on metals risk assessment, and discusses the importance of leveraging from recent major terrestrial research projects, primarily to address Registration, Evaluation, Authorization and Restriction of Chemical Substances (REACH) requirements in Europe, that have significantly advanced our understanding of the behavior and toxicity of metals in soils. These projects developed large data sets that are useful for the risk assessment of metals in soil environments. The workshop attendees met to work toward developing a process for establishing ecological soil clean-up values (Eco-SCVs). The goal of the workshop was to progress from ecological soil screening values (Eco-SSLs) to final clean-up values by providing regulators with the methods and processes to incorporate bioavailability, normalize toxicity thresholds, address food-web issues, and incorporate background concentrations. The REACH data sets were used by workshop participants as case studies in the development of the ecological standards for soils. The workshop attendees discussed scientific advancements in bioavailability, soil biota and wildlife case studies, soil processes, and food-chain modeling. In addition, one of the workgroups discussed the processes needed to frame the topics to gain regulatory acceptance as a directive or guidance by Canada, the USEPA, or the United States.

  18. Environmental benefits of Boston Harbor clean-up projects

    SciTech Connect

    Connor, M.S.; Smith, W.M. )

    1990-01-09

    The Massachusetts Water Resources Authority has undertaken one of the largest public works projects in the country to control the pollution of Boston Harbor. The project includes construction of a new primary and secondary treatment plant and sludge treatment facilities, excavation of a long ocean outfall and diffuser, and a solution to the overflow of mixed sewage and stormwater during storms; it will take over twenty years and billions of dollars to construct. A comparison of the relative costs and environmental benefits of relative costs and environmental benefits of the various construction projects, and other pollution control strategies, shows that some projects are more cost-effective than others for solving specific pollution problems. The capture and treatment of combined sewer overflow (CSO) will result in a more dramatic reduction of pathogen contamination than will completion of the primary and secondary treatment plants. Although the flow of raw sewage is intermittent and relatively small, it has high concentrations of bacteria and viruses. On the other hand, the new treatment plants will be more important in reducing toxic contamination of fish and shellfish. In summary, all the planned clean-up projects appear to be necessary to reach the goal of a swimmable, fishable Boston Harbor.

  19. Establishing a universal swabbing and clean-up protocol for the combined recovery of organic and inorganic explosive residues.

    PubMed

    Song-im, Nopporn; Benson, Sarah; Lennard, Chris

    2012-11-30

    A single-step solvent extraction and a solid-phase extraction (SPE) clean-up procedure was developed and optimised in order to establish a universal sampling and clean-up protocol for the combined recovery of organic and inorganic explosive residues. Mixtures of three common swabbing solvents (acetone, acetonitrile and methanol) with water, in various ratios, were assessed for the extraction of four target organic explosives [pentaerythritol tetranitrate (PETN), 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and triacetone triperoxide (TATP)] and two inorganic anions (chlorate and nitrate) from alcohol wipes that were used as a swabbing medium. An efficient, single-step extraction of both organic and inorganic compounds from the wipes was achieved using 60% v/v methanol/water. To develop a clean-up procedure, four commercially available SPE cartridges (Oasis HLB, Isolute(®) C18, Bond-Elut(®) ENV and ABS ELUT Nexus) and an in-house packed XAD-7 cartridge were firstly evaluated for their retention capacity toward three organic explosives (PETN, TNT and RDX) in a mixture of methanol and water. A SPE technique was then developed and optimised from the short-listed sorbents with four representative organic explosives (including TATP). The Nexus cartridge was found to provide a suitable sorbent for extract clean-up following swab extraction with 60% v/v methanol/water. By incorporating the optimised clean-up procedure with the application of a polyester-based alcohol wipe as a sampling medium, a universal swabbing protocol for the combined recovery of both organic and inorganic explosive residues was established. The feasibility of the proposed protocol was assessed by collection and quantitation of the residue from a mixture of TNT, PETN and chlorate deposited on a laminate test surface. PMID:22959657

  20. Establishing a universal swabbing and clean-up protocol for the combined recovery of organic and inorganic explosive residues.

    PubMed

    Song-im, Nopporn; Benson, Sarah; Lennard, Chris

    2012-11-30

    A single-step solvent extraction and a solid-phase extraction (SPE) clean-up procedure was developed and optimised in order to establish a universal sampling and clean-up protocol for the combined recovery of organic and inorganic explosive residues. Mixtures of three common swabbing solvents (acetone, acetonitrile and methanol) with water, in various ratios, were assessed for the extraction of four target organic explosives [pentaerythritol tetranitrate (PETN), 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and triacetone triperoxide (TATP)] and two inorganic anions (chlorate and nitrate) from alcohol wipes that were used as a swabbing medium. An efficient, single-step extraction of both organic and inorganic compounds from the wipes was achieved using 60% v/v methanol/water. To develop a clean-up procedure, four commercially available SPE cartridges (Oasis HLB, Isolute(®) C18, Bond-Elut(®) ENV and ABS ELUT Nexus) and an in-house packed XAD-7 cartridge were firstly evaluated for their retention capacity toward three organic explosives (PETN, TNT and RDX) in a mixture of methanol and water. A SPE technique was then developed and optimised from the short-listed sorbents with four representative organic explosives (including TATP). The Nexus cartridge was found to provide a suitable sorbent for extract clean-up following swab extraction with 60% v/v methanol/water. By incorporating the optimised clean-up procedure with the application of a polyester-based alcohol wipe as a sampling medium, a universal swabbing protocol for the combined recovery of both organic and inorganic explosive residues was established. The feasibility of the proposed protocol was assessed by collection and quantitation of the residue from a mixture of TNT, PETN and chlorate deposited on a laminate test surface.

  1. Biomonitoring of workers cleaning up ammunition waste sites.

    PubMed

    Sabbioni, Gabriele; Rumler, Richard

    2007-01-01

    2,4,6-Trinitrotoluene (TNT) is an important occupational and environmental pollutant. In TNT-exposed humans, notable toxic manifestations have included aplastic anaemia, toxic hepatitis, cataracts, hepatomegaly and liver cancer. Therefore, it is important to develop protection measures and to monitor workers involved in the clean-up of ammunition sites. Haemoglobin (Hb) adducts of TNT, 4-amino-2,6-dinitrotoluene (4ADNT) and 2-amino-4,6-dinitrotoluene (2ADNT), and the urine metabolites of TNT, 4ADNT and 2ADNT were found in 22-50% of the exposed workers, but not in the control group. The exposed workers were wearing protective equipment. The levels of erythrocytes, haemoglobin, creatinine, serum glutamic pyruvic transaminase and lymphocyte levels were significantly lower in the exposed workers than in the non-exposed workers. The levels of blood urea and reticulocytes were significantly higher in the exposed workers than in the non-exposed workers. Headache (26%), mucous membrane irritation (16%), sick leave (18%), lassitude (8%), anxiety (6%), shortness of breath (3%), nausea (5%) and allergic reactions (8%) were reported by the exposed workers. In a further analysis the U-4ADNT levels and the Hb-adduct levels were compared to the blood parameter and the health effects. The blood parameters were not significantly different between the U-4ADNT positive and U-4ADNT-negative group. Headache, mucous membrane irritation, sick leave, lassitude, anxiety, shortness of breath and allergic reactions were statistically not different between the two groups. Also in the workers with Hb-4ADNT adducts no significant negative changes were seen in regards to the changes of the blood parameters or the health effects. According to the results of the present study, it appears that the blood parameter changes and the health effects are more influenced by other factors than by the internal exposure to TNT.

  2. Using Phytoremediation to Clean Up Contamination at Military Installations

    SciTech Connect

    Zellmer, S.D.; Hinchman, R.R.; Negri, M.C.; Schneider, J.F.; Gatliff, E.G.

    1997-07-01

    During and following World War II, wastes from the production of munitions and other military materials were disposed of using the best available practices acceptable at that time. However, these disposal methods often contaminated soil and groundwater with organic compounds and metals that require cleanup under current regulations. An emerging technology for cleaning contaminated soils and shallow groundwater is phytoremediation, an environmentally friendly, low- cost, and low-tech process. Phytoremediation encompasses all plant- influenced biological, chemical, and physical processes that aid in the uptake, degradation, and metabolism of contaminants by either plants or free-living organisms in the plant`s rhizosphere. A phytoremediation system can be viewed as a biological, solar-driven, pump-and-treat system with an extensive, self-extending uptake network (the root system) that enhances the soil and below-ground ecosystem for subsequent productive use. Argonne National Laboratory (ANL) has been conducting basic and applied research in phytoremediation since 1990. Initial greenhouse studies evaluated salt-tolerant wetland plants to clean UP and reduce the volume of salty `produced water` from petroleum wells. Results of these studies were used to design a bioreactor for processing produced water that is being demonstrated at a natural gas well in Oklahoma; this system can reduce produced water volume by about 75% in less than eight days, representing substantial savings in waste disposal cost. During 1994, ANL conducted a TNT plant uptake and in situ remediation study in a ridge-and-furrow area used for the disposal of pink water at the Joliet Army Ammunition Plant.

  3. Comparison of solid phase extraction, saponification and gel permeation chromatography for the clean-up of microwave-assisted biological extracts in the analysis of polycyclic aromatic hydrocarbons.

    PubMed

    Navarro, P; Cortazar, E; Bartolomé, L; Deusto, M; Raposo, J C; Zuloaga, O; Arana, G; Etxebarria, N

    2006-09-22

    The feasibility of different clean-up procedures was studied for the determination of polycyclic aromatic hydrocarbons (PAHs) in biota samples such as oysters, mussels and fish liver. In this sense, once the samples were extracted--essentially with acetone and in a microwave system--and before they could be analysed by gas chromatography-mass spectrometry (GC-MS), three different approaches were studied for the clean-up step: solid phase extraction (SPE), microwave-assisted saponification (MAS) and gel permeation chromatography (GPC). The main aim of this work was to maximise the recoveries of PAHs and to minimise the presence of interfering compounds in the last extract. In the case of SPE, Florisil cartridges of 1, 2 and 5 g, and silica cartridges of 5 g were studied. In that case, and with oysters and mussels, microwave-assisted extraction and 5 g Florisil cartridges provided good results. In addition, the concentrations obtained for Standard Reference Material (SRM) NIST 2977 (mussel tissue) were in good agreement with the certified values. In the case of microwave-assisted saponification, the extracts were not as clean as those obtained with 5 g Florisil and this fact lead to overestimate the concentration of the heaviest PAHs. Finally, the cleanest extracts were obtained by GPC. The method was successfully applied to mussels, oysters and hake liver, and the results obtained for NIST 2977 (mussel tissue) were within the confidence interval of the certified reference material for most of the certified analytes.

  4. Evaluation of an automated clean-up system for the isotope-dilution high-resolution mass spectrometric analysis of PCB, PCDD, and PCDF in food.

    PubMed

    Eljarrat, E; Sauló, J; Monjonell, A; Caixach, J; Rivera, J

    2001-12-01

    An automated clean-up system was evaluated for the simultaneous analysis of polychiorinated dibenzo-p-dioxins (PCDD), dibenzofurans (PCDF), and biphenyls (PCB) in different foods. In addition to the seventeen 2,3,7,8-substituted PCDDIPCDF and four non-ortho PCB, by use of the clean-up system studied, it was possible to collect the eight mono-ortho and two di-ortho PCB and the seven indicator PCB in two separate fractions during the same clean-up run. The study was first performed using standard mixtures containing PCDD, PCDF and PCB, and a certified reference material. The recoveries of the 13C-labeled compounds ranged from 51 to 90%, indicating that the PCDD, PCDF, and PCB clean-up worked satisfactorily. Next, the automated system for PCDD, PCDF, and PCB analysis was evaluated for foods such as milk, egg, meat (beef, chicken, and pork), mussel, and olive oil. The recoveries of the 13C-labeled compounds ranged from 40 to 120% for PCB and from 57 to 113% for PCDD/ PCDF, meeting the requirements of well accepted methods. Thus, the automated clean-up system studied is a suitable alternative to conventional clean-up methods.

  5. [Determination of indicator polychlorinated biphenyls in vegetable oils by double clean-up-gas chromatography].

    PubMed

    Ding, Liping; Cai, Chunping; Wang, Danhong

    2014-11-01

    To investigate the residues of seven indicator polychlorinated biphenyls (PCBs) in vegetable oils, a method was established for the determination of trace PCBs in vegetable oils by double clean-up coupled with gas chromatography (GC). After extracted with acetonitrile, the sample extract was concentrated to dryness followed by re-dissolving with hexane. And the solution was pretreated by adding concentrated sulfuric acid followed cleaned-up with silica gel in dispersive solid-phase extraction protocol, then analyzed by GC with external standard meth- od. Under the optimized chromatographic conditions, the analysis was carried out with a capillary column (HP-5, 30 m x 0.32 mm x 0.25 μm) at a flow rate of 0.8 mL/min, and the sample volume was 1.00 μL. Monitoring with an electron-capture detector, all the target analytes were separated by temperature-programming of the column. Good linearities were obtained in the range of 10-500 μg/L for the seven indicator PCBs with the correlation coefficients greater than 0. 999. For different matrices, the limits of detection (S/N = 3) and limits of quantitation (S/N = 10) were in the range of 1.8-8.9 pg/kg and 5.9-29.8 μg/kg, respectively. At three spiked levels of 10, 20 and 100 μg/kg of the seven indicator PCBs in olive oil, palm oil and peanut oil blank samples, the average recoveries ranged from 71.0% to 105.5% with the RSDs of 4.0%-11.3%. The method is simple, rapid and accurate, and can be used for the routine analysis of the indicator PCBs in vegetable oils.

  6. Planar solid phase extraction clean-up and microliter-flow injection analysis-time-of-flight mass spectrometry for multi-residue screening of pesticides in food.

    PubMed

    Oellig, Claudia; Schwack, Wolfgang

    2014-07-18

    For multi-residue analysis of pesticides in food, a sufficient clean-up is essential for avoiding matrix effects in liquid and gas chromatography (LC and GC) analysis coupled to mass spectrometry (MS). In the last two years, high-throughput planar solid phase extraction (HTpSPE) was established as a new clean-up concept for pesticide residue analysis in fruits and vegetables (C. Oellig, W. Schwack, 2011) and tea (C. Oellig, W. Schwack, 2012). HTpSPE results in matrix-free extracts almost free of interferences and matrix effects. In this study, a time-of-flight mass spectrometer (TOFMS) was applied to directly analyze HTpSPE extracts for pesticide residues. This HTpSPE-microliter-flow injection analysis (μL-FIA)-TOFMS approach detects all pesticides at once in a single mass spectrum, without a liquid chromatographic separation step. Complete sample information was obtained after the injection of the cleaned extract within a single peak. Recovery studies for seven representative pesticides in four different matrices (apples, red grapes, cucumbers, tomatoes) provided mean recoveries of 86-116% with relative standard deviations of 1.3-10% (n=5) using the mass signal intensities under the entire sample peak. Comparing the mass spectra of sample peaks from spiked extracts and solvent standards indicated the efficiency of HTpSPE clean-up. A pesticide database search detected all spiked pesticides with a low incidence of false-positives. HTpSPE of one sample required a few minutes, and numerous samples could be cleaned in parallel at minimal cost with low sample and solvent consumption. The μL-FIA-TOFMS screening then needed an additional 6min per sample. The novel screening approach was successfully applied to QuEChERS extracts of several real samples, and the pesticides identified by HTpSPE-μL-FIA-TOFMS were identical to the pesticides detected by common target LC-MS/MS analyses. The high degree of concordantly identified pesticides by the new developed HTp

  7. Determination of deoxynivalenol in cereals by immunoaffinity clean-up and ultra-high performance liquid chromatography tandem mass spectrometry.

    PubMed

    Li, Yanshen; Wang, Zhanhui; De Saeger, Sarah; Shi, Weimin; Li, Cun; Zhang, Suxia; Cao, Xingyuan; Shen, Jianzhong

    2012-02-01

    An immunoaffinity column (IAC) was prepared with a new deoxynivalenol (DON) monoclonal antibody and used as a clean-up tool before ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) analysis of DON in cereals. The developed IAC clean-up method showed high recoveries for DON. They ranged from 61% to 103% in wheat, rice, and millet with intra-day and inter-day variations below 19% and 17%, respectively. The column capacity was 2.86μg DON per mL of gel, and it maintained above 0.68μg/mL of gel after 10 cycles of usage at 2 days intervals. The limit of detection (LOD) and limit of quantification (LOQ) were 0.3 and 0.8μg/kg, respectively. Twenty-one out of 40 analyzed commercial cereal samples were positive at DON concentrations from 7 to 534μg/kg.

  8. 7 CFR 27.25 - Additional samples of cotton; drawing.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Additional samples of cotton; drawing. 27.25 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Inspection and Samples § 27.25 Additional samples of cotton; drawing. In addition to the samples hereinbefore...

  9. 7 CFR 27.25 - Additional samples of cotton; drawing.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Additional samples of cotton; drawing. 27.25 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Inspection and Samples § 27.25 Additional samples of cotton; drawing. In addition to the samples hereinbefore...

  10. 7 CFR 27.25 - Additional samples of cotton; drawing.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Additional samples of cotton; drawing. 27.25 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Inspection and Samples § 27.25 Additional samples of cotton; drawing. In addition to the samples hereinbefore...

  11. 7 CFR 27.25 - Additional samples of cotton; drawing.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Additional samples of cotton; drawing. 27.25 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Inspection and Samples § 27.25 Additional samples of cotton; drawing. In addition to the samples hereinbefore...

  12. 7 CFR 27.25 - Additional samples of cotton; drawing.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Additional samples of cotton; drawing. 27.25 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Inspection and Samples § 27.25 Additional samples of cotton; drawing. In addition to the samples hereinbefore...

  13. EVALUATION OF PERSONAL COOLING DEVICES FOR A DIOXIN CLEAN-UP OPERATION

    EPA Science Inventory

    The study investigated the use of personal coolers to increase worker productivity and safety while working at elevated, ambient temperatures cleaning up dioxin contaminated soil.^The study included laboratory tests to measure the thermal characteristics of the chemical protectiv...

  14. Growing Up and Cleaning Up: The Environmental Kuznets Curve Redux

    PubMed Central

    Franklin, Rachel S.; Ruth, Matthias

    2014-01-01

    Borrowing from the Kuznets curve literature, researchers have coined the term “environmental Kuznets curve” or EKC to characterize the relationship between pollution levels and income: pollution levels will increase with income but some threshold of income will eventually be reached, beyond which pollution levels will decrease. The link between the original Kuznets curve, which posited a similar relationship between income and inequality, and its pollution-concerned offspring lies primarily with the shape of both curves (an upside-down U) and the central role played by income change. Although the EKC literature has burgeoned over the past several years, few concrete conclusions have been drawn, the main themes of the literature have remained constant, and no consensus has been reached regarding the existence of an environmental Kuznets curve. EKC research has used a variety of types of data and a range of geographical units to examine the effects of income levels on pollution. Changes in pollution levels might also be at least partly explained by countries’ position in the demographic transition and their general population structure, however little research has included this important aspect in the analysis. In addition, few analyses confine themselves to an evaluation for one country of the long-term relationship between income and pollution. Using United States CO2 emissions as well as demographic, employment, trade and energy price data, this paper seeks to highlight the potential impact of population and economic structure in explaining the relationship between income and pollution levels. PMID:25214678

  15. Growing Up and Cleaning Up: The Environmental Kuznets Curve Redux.

    PubMed

    Franklin, Rachel S; Ruth, Matthias

    2012-01-01

    Borrowing from the Kuznets curve literature, researchers have coined the term "environmental Kuznets curve" or EKC to characterize the relationship between pollution levels and income: pollution levels will increase with income but some threshold of income will eventually be reached, beyond which pollution levels will decrease. The link between the original Kuznets curve, which posited a similar relationship between income and inequality, and its pollution-concerned offspring lies primarily with the shape of both curves (an upside-down U) and the central role played by income change. Although the EKC literature has burgeoned over the past several years, few concrete conclusions have been drawn, the main themes of the literature have remained constant, and no consensus has been reached regarding the existence of an environmental Kuznets curve. EKC research has used a variety of types of data and a range of geographical units to examine the effects of income levels on pollution. Changes in pollution levels might also be at least partly explained by countries' position in the demographic transition and their general population structure, however little research has included this important aspect in the analysis. In addition, few analyses confine themselves to an evaluation for one country of the long-term relationship between income and pollution. Using United States CO2 emissions as well as demographic, employment, trade and energy price data, this paper seeks to highlight the potential impact of population and economic structure in explaining the relationship between income and pollution levels.

  16. Growing Up and Cleaning Up: The Environmental Kuznets Curve Redux.

    PubMed

    Franklin, Rachel S; Ruth, Matthias

    2012-01-01

    Borrowing from the Kuznets curve literature, researchers have coined the term "environmental Kuznets curve" or EKC to characterize the relationship between pollution levels and income: pollution levels will increase with income but some threshold of income will eventually be reached, beyond which pollution levels will decrease. The link between the original Kuznets curve, which posited a similar relationship between income and inequality, and its pollution-concerned offspring lies primarily with the shape of both curves (an upside-down U) and the central role played by income change. Although the EKC literature has burgeoned over the past several years, few concrete conclusions have been drawn, the main themes of the literature have remained constant, and no consensus has been reached regarding the existence of an environmental Kuznets curve. EKC research has used a variety of types of data and a range of geographical units to examine the effects of income levels on pollution. Changes in pollution levels might also be at least partly explained by countries' position in the demographic transition and their general population structure, however little research has included this important aspect in the analysis. In addition, few analyses confine themselves to an evaluation for one country of the long-term relationship between income and pollution. Using United States CO2 emissions as well as demographic, employment, trade and energy price data, this paper seeks to highlight the potential impact of population and economic structure in explaining the relationship between income and pollution levels. PMID:25214678

  17. Separation and determination of citrinin in corn using HPLC fluorescence detection assisted by molecularly imprinted solid phase extraction clean-up

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A liquid chromatography based method to detect citrinin in corn was developed using molecularly imprinted solid phase extraction (MISPE) sample clean-up. Molecularly imprinted polymers were synthesized using 1,4-dihydroxy-2-naphthoic acid as the template and an amine functional monomer. Density func...

  18. Multiplug filtration clean-up with multiwalled carbon nanotubes in the analysis of pesticide residues using LC-ESI-MS/MS.

    PubMed

    Zhao, Pengyue; Fan, Sufang; Yu, Chuanshan; Zhang, Junyan; Pan, Canping

    2013-10-01

    A novel design for a rapid clean-up method was developed for the analysis of pesticide residues in fruit and vegetables followed by LC-ESI-MS/MS. The acetonitrile-based sample extraction technique was used to obtain the extracts, and further clean-up was carried out by applying the streamlined procedure on a multiplug filtration clean-up column coupled with a syringe. The sorbent used for clean-up in this research is multiwalled carbon nanotubes, which was mixed with anhydrous magnesium sulfate to remove water from the extracts. This method was validated on 40 representative pesticides and apple, cabbage, and potato sample matrices spiked at two concentration levels of 10 and 100 μg/kg. It exhibited recoveries between 71 and 117% for most pesticides with RSDs < 15%. Matrix-matched calibrations were performed with the coefficients of determination >0.995 for most studied pesticides between concentration levels of 10-500 μg/L. The LOQs for 40 pesticides ranged from 2 to 50 μg/kg. The developed method was successfully applied to the determination of pesticide residues in market fruit and vegetable samples.

  19. Enhanced phyto-extraction not a feasible option to clean up uranium contaminated soil

    SciTech Connect

    Vandenhove, Hildegarde; Duquene, Lise; Wannijn, Jean; Filip, Tack; Baeten, Joke

    2007-07-01

    Available in abstract form only. Full text of publication follows: A greenhouse experiment was set up to evaluate the potential of enhanced phyto-extraction to clean up U contaminated soils. One soil had a naturally high U concentration and the other soil was impacted by effluents from the former radium extraction industry. Enhancement of U solubility and uptake by plants (ryegrass and Indian mustard) was monitored after addition of 5 chemical amendments (5 mmol kg{sup -1} soil dry weight): citric acid, ammonium citrate-citric acid mixture, oxalic acid, EDDS and NTA. Uranium solubilization and uptake were highly influenced by the amendment applied and soil-plant combinations. Citric acid was most effective in increasing U solubility (up to 18-fold increase). Citric acid and the ammonium citrate-citric acid mixture were most effective in increasing U uptake by ryegrass (up to 6-fold). For Indian mustard, EDDS and citric acid were most effective (up to 9- fold). In the optimal scenario only 0.16 % of the total uranium present in the soil could be extracted with one harvest and it would take more than 200 years to reduce the initial uranium content with 10 %. Based on these results, we must conclude that phyto-extraction is not a feasible technique to decrease the uranium concentration of historically contaminated soils. (authors)

  20. Cleaning up

    SciTech Connect

    Perry, T.S.

    1993-02-01

    This article reports on the electronics manufacturer's response to findings that chemicals used in manufacturing integrated circuits induced miscarriages in plant workers and other environmental problems such as ozone depletion and the use of heavy metals and toxic gases in manufacturing. The topics of the article include the finding that a photoresist is at fault, the phase-out of ethylene glycol ethers, alternatives to ethylene glycol ethers, ozone-eating CFCs, use of citrus derived substitutes for CFCs, alternative manufacturing processes, substitutes for other ozone depleting chemicals, and the use of heavy metals in electronics manufacturing.

  1. 21 CFR 71.4 - Samples; additional information.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... samples of the color additive, articles used as components thereof, or of the food, drug, or cosmetic in... additive, or articles used as components thereof, or of the food, drug, or cosmetic in which the color... respect to the safety of the color additive or the physical or technical effect it produces. The date...

  2. 21 CFR 71.4 - Samples; additional information.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... samples of the color additive, articles used as components thereof, or of the food, drug, or cosmetic in... additive, or articles used as components thereof, or of the food, drug, or cosmetic in which the color... respect to the safety of the color additive or the physical or technical effect it produces. The date...

  3. Analysis of polycyclic aromatic hydrocarbons in vegetable oils combining gel permeation chromatography with solid-phase extraction clean-up.

    PubMed

    Fromberg, A; Højgård, A; Duedahl-Olesen, L

    2007-07-01

    A semi-automatic method for the determination of polycyclic aromatic hydrocarbons (PAHs) in edible oils using a combined gel permeation chromatography/solid-phase extraction (GPC/SPE) clean-up is presented. The method takes advantage of automatic injections using a Gilson ASPEC XL sample handling system equipped with a GPC column (S-X3) and pre-packed silica SPE columns for the subsequent clean-up and finally gas chromatography-mass spectrometry (GC-MS) determination. The method was validated for the determination of PAHs in vegetable oils and it can meet the criteria for the official control of benzo[a]pyrene levels in foods laid down by the Commission of the European Communities. A survey of 69 vegetable oils sampled from the Danish market included olive oil as well as other vegetable oils such as rapeseed oil, sunflower oil, grape seed oil and sesame oil. Levels of benzo[a]pyrene in all the oils were low (<0.2-0.8 microg kg(-1)), except for one sample of sunflower oil containing 11 microg kg(-1) benzo[a]pyrene. PMID:17613061

  4. Application of single immunoaffinity clean-up for simultaneous determination of regulated mycotoxins in cereals and nuts.

    PubMed

    Vaclavikova, Marta; MacMahon, Shaun; Zhang, Kai; Begley, Timothy H

    2013-12-15

    A rapid and sensitive analytical strategy for the simultaneous determination of twelve mycotoxins (aflatoxins, fumonisins, zearalenon, deoxynivalenol, ochratoxin A, T-2 and HT-2 toxins) using ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) was developed and validated. The method was validated for peanuts, barley and maize-breakfast cereals; selected as they represent the matrices most often contaminated by mycotoxins. The method is designed for fast and reliable analyses of mycotoxins in regulatory, industrial and private laboratories. Multi-target immunoaffinity columns containing antibodies for all mycotoxins studied herein were used for sample clean-up. Method optimization was predominantly focused on the simplification of extraction and clean-up procedure recommended by column producers. This newly developed and simplified procedure decreased both the sample preparation time and the solvent volumes used for their processing. The analysis of all regulated mycotoxins was conducted by a newly developed UHPLC-MS/MS method with a sample run time of only ten minutes. The method trueness was tested with analytical spikes and certified reference materials, with recoveries ranging from 71% to 112% for all of the examined mycotoxins.

  5. Use of solid phase extraction for the isolation and clean-up of a derivatised furazolidone metabolite from animal tissues.

    PubMed

    Conneely, A; Nugent, A; O'Keeffe, M

    2002-06-01

    A method is presented for the determination of protein-bound residues of furazolidone in animal tissue. The use of furazolidone in food-producing animals has been banned in the EU. Illegal use of furazolidone can be monitored most effectively by testing for bound residues containing the 3-amino-2-oxazolidone (AOZ) moiety which, unlike the parent drug, is stable and can be detected for prolonged periods after cessation of treatment. This paper reports the development of an extraction and clean-up procedure for AOZ from liver using solid phase extraction. The method replaces solvent extraction and provides extensive sample clean-up with removal of approximately 99% of the derivatising agent, 2-nitrobenzaldehyde, which may interfere with the determination. It also offers the advantage of being suitable for automation, thereby increasing throughput of samples. The extraction procedure may be used for HPLC and ELISA screening techniques. The method has been validated in fortified and incurred pig liver samples, yielding mean recovery of AOZ in excess of 60%.

  6. Analysis of sterigmatocystin in cereals, animal feed, seeds, beer and cheese by immunoaffinity column clean-up and HPLC and LC-MS/MS quantification.

    PubMed

    Marley, Elaine; Brown, Phyllis; Mackie, Jennifer; Donnelly, Carol; Wilcox, Joyce; Pietri, Amedeo; Macdonald, Susan

    2015-01-01

    A method is reported for the analysis of sterigmatocystin in various food and feed matrices using a commercial sterigmatocystin immunoaffinity column (IAC) for sample clean-up prior to HPLC analysis by UV with mass spectrometric detection (LC-MS/MS). Cereals (wheat, oats, rye, maize and rice), sunflower seeds and animal feed were spiked with sterigmatocystin at levels from 0.75 to 50 µg kg(-1) to establish method performance. Using acetonitrile/water extraction followed by IAC clean-up, and analysis by HPLC with detection at 325 nm, recoveries ranged from 68% to 106%, with repeatability from 4.2% to 17.5%. The limit of quantification with UV detection in these matrices was 1.5 µg kg(-1). For the analysis of beer and cheese the sample preparation prior to IAC clean-up was changed to accommodate the different properties of the matrix, prior to analysis by LC-MS/MS. For beer and cheese spiked at 5.0 µg kg(-1) the recoveries were 94% and 104%, and precision (RSDs) were 1.9% and 2.9% respectively. The limits of quantification by LC-MS/MS in beer and cheese were 0.02 and 0.6 µg kg(-1) respectively. The sterigmatocystin IAC was demonstrated to provide an efficient clean-up of various matrices to enable this mycotoxin to be determined by either HPLC with UV detection or LC-MS/MS.

  7. Validation data for HPLC/FLD determinations of ochratoxin A in red paprika and black pepper adopting a one-step clean-up procedure.

    PubMed

    Bononi, M; Gallone, F; Tateo, F

    2010-02-01

    Validation data for the determination of ochratoxin A (OTA) in two spice matrices, red paprika and black pepper, were obtained for samples prepared with a simplified single-step clean-up column. Extracts of finely ground samples of red paprika and black pepper were prepared and applied to a Mycosep 229 Ochra clean-up column. The purified extract was then subjected to HPLC/FLD analysis. The relative standard deviation for repeatability (RSDr) of the method was 11.8% for red paprika and 9.9% for black pepper. The limit of detection (LOD) value (three times the noise) was estimated as corresponding to the response of an extract derived from a blank matrix (previously washed) and spiked at 1.0 microg kg(-1). The limit of quantitation (LOQ) (three times LOD) was 3.0 microg kg(-1). The performance of the one-step column clean-up procedure appears to be a suitable alternative to commonly used clean-up techniques and allows the precise determination of OTA in two complex matrices.

  8. Analysis of sterigmatocystin in cereals, animal feed, seeds, beer and cheese by immunoaffinity column clean-up and HPLC and LC-MS/MS quantification.

    PubMed

    Marley, Elaine; Brown, Phyllis; Mackie, Jennifer; Donnelly, Carol; Wilcox, Joyce; Pietri, Amedeo; Macdonald, Susan

    2015-01-01

    A method is reported for the analysis of sterigmatocystin in various food and feed matrices using a commercial sterigmatocystin immunoaffinity column (IAC) for sample clean-up prior to HPLC analysis by UV with mass spectrometric detection (LC-MS/MS). Cereals (wheat, oats, rye, maize and rice), sunflower seeds and animal feed were spiked with sterigmatocystin at levels from 0.75 to 50 µg kg(-1) to establish method performance. Using acetonitrile/water extraction followed by IAC clean-up, and analysis by HPLC with detection at 325 nm, recoveries ranged from 68% to 106%, with repeatability from 4.2% to 17.5%. The limit of quantification with UV detection in these matrices was 1.5 µg kg(-1). For the analysis of beer and cheese the sample preparation prior to IAC clean-up was changed to accommodate the different properties of the matrix, prior to analysis by LC-MS/MS. For beer and cheese spiked at 5.0 µg kg(-1) the recoveries were 94% and 104%, and precision (RSDs) were 1.9% and 2.9% respectively. The limits of quantification by LC-MS/MS in beer and cheese were 0.02 and 0.6 µg kg(-1) respectively. The sterigmatocystin IAC was demonstrated to provide an efficient clean-up of various matrices to enable this mycotoxin to be determined by either HPLC with UV detection or LC-MS/MS. PMID:26515281

  9. Ecologically-based clean-up criteria for nitroaromatic explosives using toxicity test results

    SciTech Connect

    Duh, D.; Roberts, B.; Buzgo, S.

    1995-12-31

    A former trinitrotoluene (TNT) production and storage facility was the focus of a Remedial Investigation (RI). Contaminants identified during the RI included 2,4-dinitrotoluene (DNT), 2,6-DNT, and 2,4,6-TNT, PCBs, arsenic, lead and chromium. The Conceptual Site Model determined there to be several complete exposure pathways. One of these identified a route by which soil invertebrate communities could be affected through dermal contact and ingestion of soil contaminants. Maintenance of the soil invertebrate community was chosen as the assessment endpoints for this pathway in the Ecological Risk Assessment. The corresponding measurement endpoint was survival of earthworms in 14-day toxicity tests in which they were exposed to site soils. Seven surficial soil samples were collected from Areas of Concern. Each sample was evaluated for acute toxicity to earthworms using standard USEPA protocols. Chemical concentrations were also measured. An artificial soil was used as the control and diluent to establish the Lethal Concentration (LC{sub 50}) of the test soils to earthworms. From the toxicity test results and the corresponding chemical analysis, a matrix of toxicity and contaminant levels was developed. This table was used to determine a concentration of each contaminant at which no acute lethality would be expected. Lower bounds to the chemical specific LC{sub 50} values were determined and, based on sample-specific toxicity units, appropriate LC{sub 50} values were derived (333 mg/kg 2,4-DNT, 182 mg/kg 2,6-DNT, and 1960 mg/kg 2,4,6TNT). Extrapolation of this level to a chronic No Observable Adverse Effect Level (NOAEL) provided a means of proposing site-specific ecologically based clean-up criteria for the constituents of concern which would be protective of the chosen assessment endpoint.

  10. 25 CFR 170.906 - Who cleans up radioactive and hazardous material spills?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Who cleans up radioactive and hazardous material spills? 170.906 Section 170.906 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Miscellaneous Provisions Hazardous and Nuclear Waste...

  11. TECHNICAL APPROACHES TO CHARACTERIZING AND CLEANING UP BROWNFIELDS SITES: GUIDANCE DOCUMENT

    EPA Science Inventory

    NRMRL-CIN-1741 SAIC. Technical Approaches to Characterizing and Cleaning up Brownfields Sites. EPA/625/R/00/009 (NTIS PB2002-105021) , Available: 68-C7-0011. The guidance document gives assistance to communities, decision-makers, states and municipalities, academia, and the p...

  12. 25 CFR 170.906 - Who cleans up radioactive and hazardous material spills?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Who cleans up radioactive and hazardous material spills? 170.906 Section 170.906 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Miscellaneous Provisions Hazardous and Nuclear Waste...

  13. 25 CFR 170.906 - Who cleans up radioactive and hazardous material spills?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Who cleans up radioactive and hazardous material spills? 170.906 Section 170.906 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Miscellaneous Provisions Hazardous and Nuclear Waste...

  14. 25 CFR 170.906 - Who cleans up radioactive and hazardous material spills?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Who cleans up radioactive and hazardous material spills? 170.906 Section 170.906 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Miscellaneous Provisions Hazardous and Nuclear Waste...

  15. 25 CFR 170.906 - Who cleans up radioactive and hazardous material spills?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Who cleans up radioactive and hazardous material spills? 170.906 Section 170.906 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Miscellaneous Provisions Hazardous and Nuclear Waste...

  16. 75 FR 26098 - Safety Zone; Under Water Clean Up of Copper Canyon, Lake Havasu, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-11

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Under Water Clean Up of Copper Canyon, Lake... establishing a temporary safety zone on the navigable waters of Lake Havasu in the Copper Canyon in support of the underwater cleanup of Copper Canyon. This temporary safety zone is necessary to provide for...

  17. Refractive properties of separate erythrocytes of Chernobyl clean-up workers at different pH

    NASA Astrophysics Data System (ADS)

    Mazarevica, Gunta; Freivalds, Talivaldis; Bruvere, Ruta; Gabruseva, Natalija; Leice, Alevtine; Zvagule, Tija

    2000-04-01

    This study is focused on the modifications in erythrocytes of Chernobyl nuclear power plant accident clean-up workers as a late health effect of short-term impact of high level radioactive contamination. As a result, a new method based on erythrocyte refractive index properties at different pH has been elaborated.

  18. Case Study: Using Microbe Molecular Biology for Gulf Oil Spill Clean Up

    ERIC Educational Resources Information Center

    Jones, Daniel R.

    2011-01-01

    This case has the student actively investigate the regulation of expression of a novel bacterial gene in the context of attempts to solve a real world problem, clean up of the April 2010 Deep Water Horizon oil spill in the Gulf of Mexico. Although the case is fictitious, it is based on factual gene regulatory characteristics of oil-degrading…

  19. On-Line Solid-Phase Extraction Capillary Electrophoresis Mass Spectrometry for Preconcentration and Clean-Up of Peptides and Proteins.

    PubMed

    Benavente, Fernando; Medina-Casanellas, Silvia; Giménez, Estela; Sanz-Nebot, Victoria

    2016-01-01

    One of the major drawbacks of capillary electrophoresis (CE) and other microscale separation techniques, for the analysis of low abundant peptides and proteins in complex samples, are the poor concentration limits of detection. Several strategies have been developed to improve CE sensitivity. Here, we describe an on-line solid-phase extraction capillary electrophoresis mass spectrometry method with a commercial C18 sorbent for clean-up and preconcentration of neuropeptides from highly diluted biological samples.

  20. Efficiency of different protocols for enamel clean-up after bracket debonding: an in vitro study

    PubMed Central

    Sigilião, Lara Carvalho Freitas; Marquezan, Mariana; Elias, Carlos Nelson; Ruellas, Antônio Carlos; Sant'Anna, Eduardo Franzotti

    2015-01-01

    Objective: This study aimed to assess the efficiency of six protocols for cleaning-up tooth enamel after bracket debonding. Methods: A total of 60 premolars were divided into six groups, according to the tools used for clean-up: 12-blade bur at low speed (G12L), 12-blade bur at high speed (G12H), 30-blade bur at low speed (G30L), DU10CO ORTHO polisher (GDU), Renew System (GR) and Diagloss polisher (GD). Mean roughness (Ra) and mean roughness depth (Rz) of enamel surface were analyzed with a profilometer. Paired t-test was used to assess Ra and Rz before and after enamel clean-up. ANOVA/Tukey tests were used for intergroup comparison. The duration of removal procedures was recorded. The association between time and variation in enamel roughness (∆Ra, ∆Rz) were evaluated by Pearson's correlation test. Enamel topography was assessed by scanning electron microscopy (SEM). Results: In Groups G12L and G12H, original enamel roughness did not change significantly. In Groups G30L, GDU, GR and GD, a smoother surface (p < 0.05) was found after clean-up. In Groups G30L and GD, the protocols used were more time-consuming than those used in the other groups. Negative and moderate correlation was observed between time and (∆Ra, ∆Rz); Ra and (∆Ra, ∆Rz); Rz (r = - 0.445, r = - 0.475, p < 0.01). Conclusion: All enamel clean-up protocols were efficient because they did not result in increased surface roughness. The longer the time spent performing the protocol, the lower the surface roughness. PMID:26560825

  1. Planar solid phase extraction clean-up for pesticide residue analysis in tea by liquid chromatography-mass spectrometry.

    PubMed

    Oellig, Claudia; Schwack, Wolfgang

    2012-10-19

    Efficient clean-up is indispensable for preventing matrix effects in multi-residue analysis of pesticides in food by liquid and gas chromatography (LC and GC) coupled to mass spectrometry (MS). High-throughput planar solid phase extraction (HTpSPE) was recently introduced as a new clean-up concept in residue analysis of pesticides in fruit and vegetables (C. Oellig, W. Schwack, 2011 [45]). Thin-layer chromatography (TLC) was used to completely separate pesticides from matrix compounds and to focus them into a sharp zone, followed by extraction of the target zone by the TLC-MS interface. As rather challenging matrices, tea samples were chosen in this study. Besides chlorophylls and polyphenols, high amount of caffeine is co-extracted resulting in strong matrix effects both in LC-MS and GC-MS. The former HTpSPE procedure was adapted to initial extracts of green and black tea resulting in colorless extracts nearly free of matrix effects and interferences, as shown for seven chemically representative pesticides (acetamiprid, penconazole, azoxystrobin, chlorpyrifos, pirimicarb, fenarimol, and mepanipyrim). LC-MS/MS calibration curves obtained in the range of 0.002-0.5 mg/kg from matrix-matched standards and solvent standards were nearly identical and demonstrated the effectiveness of clean-up by HTpSPE. Mean recoveries determined by LC-MS/MS against solvent standards at spiking levels of 0.01 and 0.1 mg/kg ranged between 72 and 114% with relative standard deviations (RSDs) of 0.7-4.7% (n=4), while LC-MS measurements of tea samples spiked at 1 mg/kg provided recoveries of 81-104% with RSDs of 1.2-4.9% (n=6). Using LC-MS/MS, the method showed high sensitivity with signal-to-noise ratios>10 for concentrations below 0.002 mg/kg. HTpSPE of one sample was done in a few minutes, while numerous samples were cleaned in parallel at minimal costs with very low sample and solvent consumption. PMID:22981507

  2. Screening of plant and fungal metabolites in wheat, maize and animal feed using automated on-line clean-up coupled to high resolution mass spectrometry.

    PubMed

    Ates, Ebru; Godula, Michal; Stroka, Joerg; Senyuva, Hamide

    2014-01-01

    A wide range of plant and fungal metabolites can occur in cereals and feed but only a limited number of target compounds are sought. This screening method is using a database of over 600 metabolites to establish contamination profiles in food and feed. Extracts were injected directly into an automated turbulent flow sample clean-up system, coupled to a liquid-chromatography-high-resolution-mass-spectrometer (Orbitrap). Compound identification criteria for database searching were defined and the approach was validated by spiking plant and fungal metabolites into cereals and feed. A small survey of market samples (15) and quality control materials (9) of maize, wheat and feed was conducted using this method. Besides regulated and known secondary metabolites, fumiquinazoline F, fusarochromanone and dihydrofusarubin were identified for the first time in samples of maize and oats. This method enables clean-up of crude extracts within 18min and screening and confirmation of a wide range of different compound classes.

  3. Application of zirconium dioxide nanoparticle sorbent for the clean-up step in post-harvest pesticide residue analysis.

    PubMed

    Uclés, Ana; Herrera López, Sonia; Dolores Hernando, Maria; Rosal, Roberto; Ferrer, Carmen; Fernández-Alba, Amadeo R

    2015-11-01

    The use of yttria-stabilized zirconium dioxide nanoparticles as d-SPE clean-up sorbent for a rapid and sensitive liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method for the determination of post-harvest fungicides (carbaryl, carbendazim, chlorpropham, diphenylamine, ethoxyquin, flutriafol, imazalil, iprodione, methomyl, myclobutanil, pirimiphos-methyl, prochloraz, pyrimethanil, thiabendazole, thiophanate-methyl and tolclofos-methyl) in orange and pear samples has been evaluated and validated. The sample preparation was a modification of the QuEChERS extraction method using yttria-stabilized zirconium dioxide and multi-walled carbon nanotubes (MWCNTs) nanoparticles as the solid phase extraction (d-SPE) clean-up sorbents prior to injecting the ten-fold diluted extracts into the LC system. By using the yttria-stabilized zirconium dioxide extraction method, more recoveries in the 70-120% range were obtained - thus this method was used for the validation. Quantification was carried out using a matrix-matched calibration curve which was linear in the 1-500 µg kg(-1) range for almost all the pesticides studied. The validated limit of quantification was 10 µg kg(-1) for most of the studied compounds, except chlorpropham, ethoxyquin and thiophanate-methyl. Pesticide recoveries at the 10 and 100 µg kg(-1) concentration levels were satisfactory, with values between 77% and 120% and relative standard deviations (RSD) lower than 10% (n=5). The developed method was applied for the determination of selected fungicides in 20 real orange and pear samples. Four different pesticide residues were detected in 10 of these commodities; 20% of the samples contained pesticide residues at a quantifiable level (equal to or above the LOQs) for at least one pesticide residue. The most frequently-detected pesticide residues were: carbendazim, thiabendazole and imazalil-all were below the MRL. The highest concentration found was imazalil at 1175 µg kg

  4. Application of zirconium dioxide nanoparticle sorbent for the clean-up step in post-harvest pesticide residue analysis.

    PubMed

    Uclés, Ana; Herrera López, Sonia; Dolores Hernando, Maria; Rosal, Roberto; Ferrer, Carmen; Fernández-Alba, Amadeo R

    2015-11-01

    The use of yttria-stabilized zirconium dioxide nanoparticles as d-SPE clean-up sorbent for a rapid and sensitive liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method for the determination of post-harvest fungicides (carbaryl, carbendazim, chlorpropham, diphenylamine, ethoxyquin, flutriafol, imazalil, iprodione, methomyl, myclobutanil, pirimiphos-methyl, prochloraz, pyrimethanil, thiabendazole, thiophanate-methyl and tolclofos-methyl) in orange and pear samples has been evaluated and validated. The sample preparation was a modification of the QuEChERS extraction method using yttria-stabilized zirconium dioxide and multi-walled carbon nanotubes (MWCNTs) nanoparticles as the solid phase extraction (d-SPE) clean-up sorbents prior to injecting the ten-fold diluted extracts into the LC system. By using the yttria-stabilized zirconium dioxide extraction method, more recoveries in the 70-120% range were obtained - thus this method was used for the validation. Quantification was carried out using a matrix-matched calibration curve which was linear in the 1-500 µg kg(-1) range for almost all the pesticides studied. The validated limit of quantification was 10 µg kg(-1) for most of the studied compounds, except chlorpropham, ethoxyquin and thiophanate-methyl. Pesticide recoveries at the 10 and 100 µg kg(-1) concentration levels were satisfactory, with values between 77% and 120% and relative standard deviations (RSD) lower than 10% (n=5). The developed method was applied for the determination of selected fungicides in 20 real orange and pear samples. Four different pesticide residues were detected in 10 of these commodities; 20% of the samples contained pesticide residues at a quantifiable level (equal to or above the LOQs) for at least one pesticide residue. The most frequently-detected pesticide residues were: carbendazim, thiabendazole and imazalil-all were below the MRL. The highest concentration found was imazalil at 1175 µg kg

  5. Gel permeation chromatography-high performance liquid chromatography combination as an automated clean-up technique for the multiresidue analysis of fats.

    PubMed

    Rimkus, G G; Rummler, M; Nausch, I

    1996-06-14

    The well-known and almost universally utilizable clean-up technique of gel permeation chromatography (GPC) and subsequent conventional silica-gel column chromatography was automated by an on-line solvent evaporation of the GPC fraction, followed by normal-phase HPLC separation. The ternary solvent system n-hexane-toluene-acetone (88:10:2, v/v/v) was used as the mobile phase which resulted in only one HPLC fraction for all relevant analytes. The HPLC column was cleaned automatically after each sample by backflushing with polar solvents. The recoveries and reproducibilities of 35 analytes (mainly organochlorine compounds) were in the range of 77-90% and 3-7%, respectively; the high efficiency of the HPLC separation provide very clean extracts for the GC analysis. This automated clean-up technique is routinely used for the multiresidue analysis of various fat-containing food and biota samples.

  6. The NucleoSpin® DNA Clean-up XS kit for the concentration and purification of genomic DNA extracts: an alternative to microdialysis filtration.

    PubMed

    Hudlow, William R; Krieger, Robert; Meusel, Markus; Sehhat, Joshua C; Timken, Mark D; Buoncristiani, Martin R

    2011-06-01

    Traditionally, DNA extracts from biological evidence items have been concentrated and rinsed using microdialysis filtration units, including the Centricon(®) and Microcon(®) centrifugal filter devices. As an alternative to microdialysis filtration, we present an optimized method for using NucleoSpin(®) XS silica columns to concentrate and clean-up aqueous extracts from the organic extraction of DNA from biological samples. The method can be used with standard organic extraction and dithiothreitol (DTT)-based differential extraction methods with no modifications to these methods prior to the concentration and clean-up step. Extracts from laboratory-prepared bloodstains, saliva and semen stains have been successfully amplified with both qPCR and STR assays. Finally, the total time to process a set of samples with the NucleoSpin(®) XS column is approximately 30 min vs. approximately 1.5h with the Centricon(®) YM-100 filter device.

  7. From conceptual model to remediation: bioavailability, a key to clean up heavy metal contaminated soils.

    NASA Astrophysics Data System (ADS)

    Petruzzelli, Gianniantonio; Pedron, Francesca; Pezzarossa, Beatrice

    2013-04-01

    Processes of metal bioavailability in the soil To know the bioavailability processes at site specific levels is essential to understand in detail the risks associated with pollution, and to support the decision-making process, i.e. description of the conceptual model and choice of clean up technologies. It is particularly important to assess how chemical, physical and biological processes in the soil affect the reactions leading to adsorption, precipitation or release of contaminants. The measurement of bioavailability One of the main difficulties in the practical application of the bioavailability concept in soil remediation is the lack of consensus on the method to be used to measure bioavailability. The best strategy is to apply a series of tests to assess bioavailability, since no applicable method is universally valid under all conditions. As an example, bioavailability tests for phytotechnology application should consider two distinct aspects: a physico-chemical driven solubilization process and a physiologically driven uptake process. Soil and plant characteristics strongly influence bioavailability. Bioavailability as a tool in remediation strategies Bioavailability can be used at all stages in remediation strategies: development of the conceptual model, evaluation of risk assessment, and selection of the best technology, considering different scenarios and including different environmental objectives. Two different strategies can be followed: the reduction and the increase of bioavailability. Procedures that reduce bioavailability aim to prevent the movement of pollutants from the soil to the living organisms, essentially by: i) removal of the labile phase of the contaminant, i.e. the fraction which is intrinsic to the processes of bioavailability (phytostabilization); ii) conversion of the labile fraction into a stable fraction (precipitation or adsorption); iii) increase of the resistance to mass transfer of the contaminants (inertization). Procedures

  8. On-line detection of metal pollutant spikes in MSW incinerator flue gases prior to clean-up

    SciTech Connect

    Poole, D. Sharifi, V.; Swithenbank, J.; Argent, B.; Ardelt, D.

    2007-07-01

    SUWIC's unique mobile metals emissions monitoring laboratory has been used to measure metal pollutant spikes in the flue gas from a municipal solid waste incinerator, prior to gas clean-up. The laboratory has a heated sampling probe that extends into the plant, allowing the simultaneous on-line measurement of the concentrations of more than 30 metals by Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). As little is known about temporal variation in metal concentrations, this capability is seen as a major advance. The graphs of continuous measurements show that the elemental loading is far from uniform, and that concentrations fluctuate far more than may have been conventionally expected. There are occasional significant spikes in the emission profiles for cadmium and mercury, which are believed to be due to specific items in the waste feed material. Continuous monitoring measurements are of significant value for those seeking to model metal behaviour in combustion and in pollution control devices.

  9. The effect of water spray upon incineration flue gas clean-up

    NASA Astrophysics Data System (ADS)

    Wang, Haigang; Li, Bin; Liu, Shi; Pan, Zhonggang; Yan, Guizhang

    2000-06-01

    The existence of liquid water was found very important in incineration flue gas clean-up systems for enhancing the absorption of acid components contained. In a newly developed incineration flue gas clean-up tower, which works in a semi-dry mode, the water is injected in the form of spray to maximum its contact surface with the gas. The criteria for the design of the water nozzles would be high water concentration but no liquid impinging on the solid wall and complete evaporation inside the tower. In order to optimize the atomizer design, the effects of the spray type (hollow or solid cone), their initial droplet size distribution and water flow rate on the performance of the acid gas absorption were investigated. The liquid behaviour was studied with a fluid dynamic simulation code, and the overall performance was checked experimentally. This paper presents the use of a commercial CFD code, FLUENT, and some modifications made during such investigation. The modification includes the viscosity of the flue gas defined as a function of the temperature, and the initial mass fraction of different droplet size group described with an exponential distribution formula of Rosin-Rammler. The investigation results (the optimal spray parameters) were used to guide the water nozzle design. The general performance of the flue gas clean-up system measured during the plant operation complied with the design criteria.

  10. Sectored Clean-up Work Plan for Housekeeping Category Waste Sites

    SciTech Connect

    S. J. Nacht

    2000-02-01

    The Sectored Clean-up Work Plan (SCWP) replaces the Housekeeping Category Corrective Action Unit Work Plan and provides a strategy to be used for conducting housekeeping activities using a sectored clean-up approach. This work plan provides a process by which one or more existing housekeeping category Corrective Action Sites (CASS) from the Federal Facility Agreement and Consent Order and/or non-FFACO designated waste site(s) are grouped into a sector for simultaneous remediation and cleanup. This increases effectiveness and efficiencies in labor, materials, equipment, cost, and time. This plan is an effort by the U.S. Department of Energy to expedite work in a more organized and efficient approach. The objectives of this plan are to: Group housekeeping FFACO CASS and non-FFACO housekeeping sites into sectors and remediate during the same field visit; Provide consistent documentation on FFACO CAS and non-FFACO clean-up activities; Perform similar activities under one approved document; Remediate areas inside the Deactivation and Decommissioning facilities and compounds in a campaign-style remediation; and Increase efficiencies and cost-effectiveness, accelerate cleanups, reduce mobilization, demobilization, and remediation costs.

  11. A new multiple-stage electrocoagulation process on anaerobic digestion effluent to simultaneously reclaim water and clean up biogas.

    PubMed

    Liu, Zhiguo; Stromberg, David; Liu, Xuming; Liao, Wei; Liu, Yan

    2015-03-21

    A new multiple-stage treatment process was developed via integrating electrocoagulation with biogas pumping to simultaneously reclaim anaerobic digestion effluent and clean up biogas. The 1st stage of electrocoagulation treatment under the preferred reaction condition led to removal efficiencies of 30%, 81%, 37% and >99.9% for total solids, chemical oxygen demand, total nitrogen and total phosphorus, respectively. Raw biogas was then used as a reactant and pumped into the effluent to simultaneously neutralize pH of the effluent and remove H2S in the biogas. The 2nd stage of electrocoagulation treatment on the neutralized effluent showed that under the selected reaction condition, additional 60% and 10% of turbidity and chemical oxygen demand were further removed. The study concluded a dual-purpose approach for the first time to synergistically combine biogas purification and water reclamation for anaerobic digestion system, which well addresses the downstream challenges of anaerobic digestion technology.

  12. A new multiple-stage electrocoagulation process on anaerobic digestion effluent to simultaneously reclaim water and clean up biogas.

    PubMed

    Liu, Zhiguo; Stromberg, David; Liu, Xuming; Liao, Wei; Liu, Yan

    2015-03-21

    A new multiple-stage treatment process was developed via integrating electrocoagulation with biogas pumping to simultaneously reclaim anaerobic digestion effluent and clean up biogas. The 1st stage of electrocoagulation treatment under the preferred reaction condition led to removal efficiencies of 30%, 81%, 37% and >99.9% for total solids, chemical oxygen demand, total nitrogen and total phosphorus, respectively. Raw biogas was then used as a reactant and pumped into the effluent to simultaneously neutralize pH of the effluent and remove H2S in the biogas. The 2nd stage of electrocoagulation treatment on the neutralized effluent showed that under the selected reaction condition, additional 60% and 10% of turbidity and chemical oxygen demand were further removed. The study concluded a dual-purpose approach for the first time to synergistically combine biogas purification and water reclamation for anaerobic digestion system, which well addresses the downstream challenges of anaerobic digestion technology. PMID:25540943

  13. UTILIZING INNOVATIVE TECHNOLOGIES FOR ENVIRONMENTAL CLEAN-UP, SAVAHHAH RIVER SITE

    SciTech Connect

    Bergren, C

    2009-01-07

    The Savannah River Site (SRS) is a 310-square-mile United States Department of Energy nuclear facility located along the Savannah River near Aiken, South Carolina. During operations, which started in 1951, hazardous substances (chemicals and radionuclides) were released to the environment. The releases occurred as a result of inadvertent spills and waste disposal in unlined pits and basins which was common practice before environmental regulations existed. The hazardous substances have migrated to the vadose zone and groundwater in many areas of the SRS, resulting in 515 waste units and facilities that are required by environmental regulations, to undergo characterization and, if needed, remediation. In the initial years of the SRS environmental cleanup program (early 1990s), the focus was to use common technologies (such as pump and treat, air stripping, excavation and removal) that actively and tangibly removed contamination. Exclusive use of these technologies required continued and significant funding while often failing to meet acceptable clean-up goals and objectives. Recognizing that a more cost-effective approach was needed, SRS implemented new and complementary remediation methods focused on active and passive technologies targeted to solve specific remediation problems. Today, SRS uses technologies such as chemical/pH-adjusting injection, phytoremediation, underground cutoff walls, dynamic underground stripping, soil fracturing, microbial degradation, baroballs, electrical resistance heating, soil vapor extraction, and microblowers to more effectively treat contamination at lower costs. Additionally, SRS's remediation approach cost effectively maximizes cleanup as SRS works proactively with multiple regulatory agencies. Using GIS, video, animation, and graphics, SRS is able to provide an accurate depiction of the evolution of SRS groundwater and vadose zone cleanup activities to convince stakeholders and regulators of the effectiveness of various cleanup

  14. Clean-up of a pesticide-lanolin mixture by gel permeation chromatography.

    PubMed

    López-Mesas, M; Crespi, M; Brach, J; Mullender, J P

    2000-12-01

    In this study, the efficiency of a clean-up method by gel permeation chromatography (GPC) for the separation of pesticides from lanolin is analyzed. The pesticides analyzed belong to two different families, organophosphorous and synthetic pyrethroids. Lanolin, a standard mixture of the pesticides, and a lanolin-pesticides mixture are injected in a GPC column. The recoveries and elution times from the GPC column of lanolin (by a gravimetric method) and pesticides (by gas chromatography-electron capture detector) are determined. From this column, a good separation of the lanolin-pesticides mixture is observed. PMID:11144515

  15. Use of sediment serial dilution series to establish biological effect levels and clean-up goals

    SciTech Connect

    Timmer, E.; DeLong, T.; Millard, J.; Dobroski, C.

    1995-12-31

    A sediment serial dilution study was used to determine biological effect levels for two freshwater invertebrates, Chironomus tentans and Hyalella azteca. The sediments for the test were collected from a New England brook which contained elevated levels of lead and polychlorinated aromatic hydrocarbons. The objective of the sediment dilution study was two-fold: (1 ) to provide a site-specific estimation of biological effect levels, thus reducing uncertainties associated with using literature-based values, and (2) to establish clean-up goals specific to this freshwater system.

  16. Clean-up of a pesticide-lanolin mixture by gel permeation chromatography.

    PubMed

    López-Mesas, M; Crespi, M; Brach, J; Mullender, J P

    2000-12-01

    In this study, the efficiency of a clean-up method by gel permeation chromatography (GPC) for the separation of pesticides from lanolin is analyzed. The pesticides analyzed belong to two different families, organophosphorous and synthetic pyrethroids. Lanolin, a standard mixture of the pesticides, and a lanolin-pesticides mixture are injected in a GPC column. The recoveries and elution times from the GPC column of lanolin (by a gravimetric method) and pesticides (by gas chromatography-electron capture detector) are determined. From this column, a good separation of the lanolin-pesticides mixture is observed.

  17. Additional sampling directions improve detection range of wireless radiofrequency probes

    PubMed Central

    Mada, Marius; Carpenter, T. Adrian; Sawiak, Stephen J.; Williams, Guy B.

    2015-01-01

    Purpose While MRI is enhancing our knowledge about the structure and function of the human brain, subject motion remains a problem in many clinical applications. Recently, the use of wireless radiofrequency markers with three one‐dimensional (1D) navigators for prospective correction was demonstrated. This method is restricted in the range of motion that can be corrected, however, because of limited information in the 1D readouts. Methods Here, the limitation of techniques for disambiguating marker locations was investigated. It was shown that including more sampling directions extends the tracking range for head rotations. The efficiency of trading readout resolution for speed was explored. Results Tracking of head rotations was demonstrated from −19.2 to 34.4°, −2.7 to 10.0°, and −60.9 to 70.9° in the x‐, y‐, and z‐directions, respectively. In the presence of excessive head motion, the deviation of marker estimates from SPM8 was reduced by 17.1% over existing three‐projection methods. This was achieved by using an additional seven directions, extending the time needed for readouts by a factor of 3.3. Much of this increase may be circumvented by reducing resolution, without compromising accuracy. Conclusion Including additional sampling directions extends the range in which markers can be used, for patients who move a lot. Magn Reson Med 76:913–918, 2016. © 2015 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. PMID:26418189

  18. Early Aging in Chernobyl Clean-Up Workers: Long-Term Study

    PubMed Central

    Krasnov, V.; Kryukov, V.; Samedova, E.; Emelianova, I.; Ryzhova, I.

    2015-01-01

    This paper represents data of long-term open prospective study. 312 male clean-up workers, who participated in elimination of the Chernobyl disaster consequences in 1986-87, were observed and examined in Moscow Research Institute of Psychiatry. The average age of patients was 57,0 ± 6,8 years. All patients were diagnosed with psychoorganic syndrome, caused by combination of different factors, which led to early cerebrovascular pathology, which was confirmed by clinical, neuropsychological, and instrumental examination. Anamnesis and the level of social adaptation were also assayed. Clinical estimation was done with the use of specially developed Clinical Psychopathological Chart. All the symptoms were divided into 4 groups (asthenic, psychovegetative, dysthymic, and cognitive symptom-complexes). No pronounced signs of dementia were observed. The control group included 44 clean-up workers without mental disorders. Predomination of various exogenous factors before and after accident was noted. Therapy included different vasotropic remedies, as well as family therapy, art therapy, and cognitive training. The possibilities of the reverse development of symptoms were statistically proved. The results allow making a conclusion that these disorders could not be explained either by radiation effects or by PTSD but connected with cerebrovascular pathology. PMID:25692150

  19. Spinning filter separation system for oil spill clean-up operation

    SciTech Connect

    Wehrle, J.; Fischer, E.C.; Kenney, W.P.; Korczynski, J.F.; Gracik, T.D.

    1996-09-26

    According to current technology, effective clean up of oil spills from the surface of ocean water is performed by an oil sweeper vessel within which oil contaminated water is collected for transport to remotely located on-shore equipment within which oil separation and disposal is performed. The processing of large quantities of oil polluted ocean water is accordingly time consuming as well as costly. It is therefore an important object of the present invention to provide a less costly oil spill clean up system involving more rapid processing of large quantities of oil polluted ocean water. In accordance with the present invention, oil polluted ocean water is processed at an oil spill location by continuous separation during pressurized flow of the water through at least two separator devices within which successive reduction in oil concentration is effected with respect to a separated portion of the water by filtered flow through porous membrane walls to correspondingly increase the oil concentration within the other remaining portion of water being processed. The first portion of the processed water when sufficiently reduced in oil concentration is discharged for return to the oil spill location, while the remaining portion is collected until a sufficient level of oil concentration therein is achieved to permit disposal thereof by burning at the oil spill site.

  20. Site-specific sediment clean-up objectives developed by the sediment quality triad

    SciTech Connect

    Redman, S.; Janisch, T.

    1995-12-31

    Sediment chemistry, sediment toxicity, and benthic macroinvertebrate community data were collected and evaluated in concert (1) to characterize adverse effects of hydrocarbon and metal contaminants in the sediments of a small inlet of Superior Bay, Lake Superior and a tributary creek and (2) to derive numeric objectives for the clean up of this system. Sediments from reference locations and eight study sites were analyzed for a range of contaminants, including hydrocarbons (measured both as diesel range organics (DRO) and oil and grease), lead, chromium, and ammonia. A range of sediment toxicity was observed across the eight study sites using a variety of tests and endpoints: Hyalella azteca (10 day survival and growth), Chironomus tentans (10 day survival and growth), Ceriodaphnia dubia (48 hour survival), and Daphnia magna (48 hour survival and 10 day survival and reproduction). A range of alterations of the benthic macroinvertebrate community compared with communities from reference locations were observed. Benthic community alterations were summarized quantitatively by taxa richness and Shannon-Weiner mean diversity. Lowest effect levels determined through this study included 150 {micro}g/g dry sediment for DRO (as measured in this study) and 40 {micro}g/g dry sediment for lead. Effects thresholds determined through this study included 1,500 {micro}g/g dry sediment for DRO and 90 {micro}g/g dry sediment for lead. These levels and concentrations measured in relevant reference locations are being used to define objectives for sediment clean up in the inlet and creek.

  1. [Structural and functional changes of myocardium in Chernobyl disaster clean-up workers with atrial fibrillation].

    PubMed

    Khomaziuk, I M; Habulavichene, Zh M; Khomaziuk, V A

    2011-01-01

    Particularities and clinical importance of the structural and functional changes of myocardium were estimated in Chernobyl disaster clean-up workers with atrial fibrillation (AF). We examined 122 men with AF, which was associated with ischemic heart disease and arterial hypertension. Paroxysmal AF was diagnosed in 42 patients, 80 patients had permanent AE Control group comprised 80 men without AF. Echocardiography and Doppler studies were performed using ultrasound scanner Aloka SSD-630 (Japan). Significant structural and functional changes of the heart were revealed already in paroxysmal AF and became more pronounced in permanent AF. Increased left atrial size, its ratio to left ventricular end diastolic diameter, diastolic dysfunction were important echocardiographic predictors of AF. Heart walls thickening was accompanied by disorders of myocardial relaxation, increase in myocardial mass led to ischemia, and together they promoted overload, dysfunction of atrium and development of AF. Obligatory echocardiographic examination of the Chernobyl disaster clean-up workers with ischemic heart disease and arterial hypertension is necessary for predicting AF early, ordering adequate therapy in proper time and improving prognosis.

  2. Validation of an HPLC analytical method coupled to a multifunctional clean-up column for the determination of deoxynivalenol.

    PubMed

    Sugita-Konsihi, Yoshiko; Tanaka, Toshitsugu; Tabata, Setsuko; Nakajima, Masahiro; Nouno, Masanori; Nakaie, Yoko; Chonan, Takao; Aoyagi, Mitsutoshi; Kibune, Nobuyuki; Mizuno, Kazutoshi; Ishikuro, Eiichi; Kanamaru, Naoki; Minamisawa, Masatoshi; Aita, Norio; Kushiro, Masayo; Tanaka, Kenji; Takatori, Kosuke

    2006-04-01

    To evaluate a method using a multifunctional clean-up column coupled with high performance liquid chromatography as an official analytical method for the determination of deoxynivalenol in wheat used as food or feed, an inter-laboratory study was performed in 12 laboratories using four naturally contaminated wheat samples and one spiked sample. The relative standard deviations for repeatability (RSDr) and reproducibility (RSDR) of naturally contaminated wheat were in the range 5.8-11.3% and 12.0-20.7%, respectively. The HORRAT was less than 1.0 in each sample. From the spiking test, the recovery rate, RSDr, RSDR and HORRAT value were 100.0%, 11.2%, 10.3% and 0.5, respectively. The limit of quantification is 0.10 mg/kg from the range obtained in a linear calibration. Thus, it should be useful as a sensitive and validated analytical method for the determination of deoxynivalenol in wheat intended for use in food and feed.

  3. Estimation of the uncertainties of extraction and clean-up steps in pesticide residue analysis of plant commodities.

    PubMed

    Omeroglu, P Yolci; Ambrus, A; Boyacioglu, D

    2013-01-01

    Extraction and clean-up constitute important steps in pesticide residue analysis. For the correct interpretation of analytical results, uncertainties of extraction and clean-up steps should be taken into account when the combined uncertainty of the analytical result is estimated. In the scope of this study, uncertainties of extraction and clean-up steps were investigated by spiking (14)C-labelled chlorpyrifos to analytical portions of tomato, orange, apple, green bean, cucumber, jackfruit, papaya and starfruit. After each step, replicate measurements were carried out with a liquid scintillation counter. Uncertainties in extraction and clean-up steps were estimated separately for every matrix and method combination by using within-laboratory reproducibility standard deviation and were characterised with the CV of recoveries. It was observed that the uncertainty of the ethyl acetate extraction step varied between 0.8% and 5.9%. The relative standard uncertainty of the clean-up step with dispersive SPE used in the method known as QuEChERS was estimated to be around 1.5% for tomato, apple and green beans. The highest variation of 4.8% was observed in cucumber. The uncertainty of the clean-up step with gel permeation chromatography ranged between 5.3% and 13.1%, and it was relatively higher than that obtained with the dispersive SPE method.

  4. Does further clean-up reduce the matrix enhancement effect in gas chromatographic analysis of pesticide residues in food?

    PubMed

    Schenck, F J; Lehotay, S J

    2000-01-28

    Sample extracts of apples, peas, green beans, oranges, raspberries, clementines, carrots, and wheat obtained using the Food and Drug Administration (acetone extraction) and Canadian Pest Management Regulatory Agency (acetonitrile extraction) multiresidue methods for pesticides were subjected to clean-up using different solid-phase extraction (SPE) cartridges in an attempt to reduce or eliminate the matrix enhancement effect. The matrix enhancement effect is related to the blocking of active sites on the injector liner by matrix components, thereby increasing signal in the presence of matrix versus standards in solvent in which the pesticides themselves interact with the active sites. Graphitized carbon black (GCB) was often used in combination with various anion-exchange SPE cartridges. The extracts were then spiked with organophosphorus insecticides. These process standards were then compared to standards in acetone of the same concentration using gas chromatography with flame photometric detection or ion trap mass spectrometric detection. Sample matrix enhancement varied from little to no effect for some pesticides (e.g. chlorpyrifos, malathion) to >200% in the case of certain susceptible pesticides. The GCB removed color components but showed little effect in reducing matrix enhancement by itself. The anion-exchange cartridges in combination with GCB or not, substantially reduced the matrix enhancement effect but did not eliminate it. PMID:10677079

  5. Cleaning-up atrazine-polluted soil by using Microbial Electroremediating Cells.

    PubMed

    Domínguez-Garay, Ainara; Boltes, Karina; Esteve-Núñez, Abraham

    2016-10-01

    Biodegradation of pollutants in soil is greatly limited by the availability of terminal electron acceptors required for supporting microbial respiration. Such limitation can be overcome if soil-buried electrodes accept the electrons released in the microbial metabolism. We propose the term bioelectroventing for such a environmental treatment. The process would be performed in a device so-called Microbial Electroremediating Cell. Indeed, our studies demonstrate that the presence of electrodes as electron acceptors effectively stimulated by 5-fold the biodegradation rate of the herbicide atrazine (2-chloro-4-ethylamino-6-isopropyl amino-1,3,5-triazine) in comparison with soil natural attenuation. Furthermore, a different set of toxicological test using Pseudokirchneriella subcapitata green alga e, Salmonella typhimorium bacteria and Sorghum saccharatum plant seeds respectively, confirm that atrazine-polluted soil can be effectively cleaned-up in short time by the use of MERCs. PMID:27448317

  6. Transgenic plants for phytoremediation: helping nature to clean up environmental pollution.

    PubMed

    Van Aken, Benoit

    2008-05-01

    Phytoremediation is the use of plants to clean up environmental pollution. However, detoxification of organic pollutants by plants is often slow, leading to the accumulation of toxic compounds that could be later released into the environment. A recent publication by Doty and colleagues describes the development of transgenic poplars (Populus) overexpressing a mammalian cytochrome P450, a family of enzymes commonly involved in the metabolism of toxic compounds. The engineered plants showed enhanced performance with regards to the metabolism of trichloroethylene and the removal of a range of other toxic volatile organic pollutants, including vinyl chloride, carbon tetrachloride, chloroform and benzene. This work suggests that transgenic plants might be able to contribute to the wider and safer application of phytoremediation.

  7. Case study: Using microbe molecular biology for Gulf oil spill clean up.

    PubMed

    Jones, Daniel R

    2011-01-01

    This case has the student actively investigate the regulation of expression of a novel bacterial gene in the context of attempts to solve a real world problem, clean up of the April 2010 Deep Water Horizon oil spill in the Gulf of Mexico. Although the case is fictitious, it is based on factual gene regulatory characteristics of oil-degrading microbes. The case is written for a sophomore Cell Biology lecture course at Indiana Wesleyan University that is taught to Biology/Pre-Med majors. This study is also appropriate for use in undergraduate microbiology, biochemistry, molecular biology, and molecular genetics courses. The case is intended to enhance coverage of transcription, translation, control of gene expression, and selected molecular biology techniques. Opportunities to practice critical thinking skills and to a lesser extent an introduction to the paradigm of life science research at the industry level are provided.

  8. Chemistry and microbiology of permeable reactive barriers for in situ groundwater clean up.

    PubMed

    Scherer, M M; Richter, S; Valentine, R L; Alvarez, P J

    2000-01-01

    Permeable reactive barriers (PRBs) are receiving a great deal of attention as an innovative, cost-effective technology for in situ clean up of groundwater contamination. A wide variety of materials are being proposed for use in PRBs, including zero-valent metals (e.g., iron metal), humic materials, oxides, surfactant-modified zeolites (SMZs), and oxygen- and nitrate-releasing compounds. PRB materials remove dissolved groundwater contaminants by immobilization within the barrier or transformation to less harmful products. The primary removal processes include: (1) sorption and precipitation, (2) chemical reaction, and (3) biologically mediated reactions. This article presents an overview of the mechanisms and factors controlling these individual processes and discusses the implications for the feasibility and long-term effectiveness of PRB technologies.

  9. Cleaning-up atrazine-polluted soil by using Microbial Electroremediating Cells.

    PubMed

    Domínguez-Garay, Ainara; Boltes, Karina; Esteve-Núñez, Abraham

    2016-10-01

    Biodegradation of pollutants in soil is greatly limited by the availability of terminal electron acceptors required for supporting microbial respiration. Such limitation can be overcome if soil-buried electrodes accept the electrons released in the microbial metabolism. We propose the term bioelectroventing for such a environmental treatment. The process would be performed in a device so-called Microbial Electroremediating Cell. Indeed, our studies demonstrate that the presence of electrodes as electron acceptors effectively stimulated by 5-fold the biodegradation rate of the herbicide atrazine (2-chloro-4-ethylamino-6-isopropyl amino-1,3,5-triazine) in comparison with soil natural attenuation. Furthermore, a different set of toxicological test using Pseudokirchneriella subcapitata green alga e, Salmonella typhimorium bacteria and Sorghum saccharatum plant seeds respectively, confirm that atrazine-polluted soil can be effectively cleaned-up in short time by the use of MERCs.

  10. The integration of science and politics to clean up 50 years in the nuclear sandbox

    SciTech Connect

    Lyons, C.E.; Holeman, T.

    1999-07-01

    The Cold War was fought between world superpowers for approximately 40 years from the end of the second World War until the end of the 1980s. During that time, the US government devoted billions of dollars to the development and production of nuclear weapons. Now the Cold War is over and the US is left with numerous nuclear weapons factories, stockpiles of nuclear materials, and mountains of waste to decontaminate and decommission. In the heat of the Cold War, little or no thought was given to how the facilities building bombs would be dismantled. Far too little attention was paid to the potential human health and environmental impact of the weapons production. Now, dozens of communities across the country face the problems this negligence created. In many cases, the location, extent, and characteristics of the waste and contamination are unknown, due to negligence or due to intentional hiding of waste and associated problems. Water supplies are contaminated and threatened; air quality is degraded and threatened; workers and residents risk contamination and health impacts; entire communities risk disaster from potential nuclear catastrophe. The US government, in the form of the US Department of Energy (DOE), now accepts responsibility for creating and cleaning up the mess. But it is the local communities, the home towns of the bomb factories and laboratories, that carry a significant share of the burden of inventing the science and politics required to clean up 50 years in the nuclear sandbox. The purpose of this paper is to evaluate the role of the local community in addressing the cleanup of the US nuclear weapons complex. Local governments do not own nor are responsible for the environmental aftermath, but remain the perpetual neighbor to the facility, the hometown of workers, and long-term caretaker of the off-site impacts of the on-site contamination and health risks.

  11. Studies of leukemia and thyroid disease among Chernobyl clean-up workers from the Baltics

    SciTech Connect

    Inskip, P.D.; Tekkel, M.; Rahu, M.

    1997-03-01

    Following the reactor accident at Chernobyl in late April of 1986, hundreds of thousands of men from throughout the former Soviet Union were sent to Chernobyl to entomb the damaged reactor, remove radioactive debris, and help decontaminate the local environment. They remained for an average of three months and were allowed to accumulate up to 25 cGy of radiation before being sent home. Doses for some workers may have exceeded the allowable limit. The experience of Chernobyl clean-up workers is potentially informative about cancer risk associated with protracted exposure to low levels of radiation. Cohorts of clean-up workers from the Baltic Republics were assembled for study, based on military records and other lists. The study population includes 4,833 men from Estonia 5,709 from Latvia and at least 5,446 from Lithuania, where a pilot study is underway. They are being monitored for cancer incidence through linkages with the corresponding national cancer registries. Biodosimetric assays, including fluorescent in situ hybridization (FISH) for chromosome translocation analysis and the glycophorin A (GPA) somatic cell mutation assay, are being used to supplement information about radiation doses from worker records and questionnaires. Thyroid screening examinations, including palpation, ultrasound and, selectively, fine-needle aspiration biopsies were performed on nearly 2,000 workers in the Estonian cohort (mean age, 40 y) during the spring of 1995, nine years after the reactor accident. The study is still in progress. Work began first in Estonia, and results presented here pertain to this subgroup except as otherwise noted. The average age at the time of arrival at Chernobyl was 31 years. 62% were sent in 1986. Possible reasons for the apparent absence or rarity of radiation-induced thyroid nodules include low and protracted doses, low susceptibility among men exposed as adults, and insufficient passage of time since the accident.

  12. Quantifying the clean-up of LNAPL lens and LNAPL entrapped in an aquifer composed of fractured permeable formation

    NASA Astrophysics Data System (ADS)

    Rubin, H.; Koengeter, J.

    2006-12-01

    This study has originated and motivated by a case history of a comparatively wide scale of kerosene (LNAPL) contamination in an aquifer composed of a fractured permeable formation. Presently, parts of the LNAPL are entrapped within the top layers of the aquifer, and other parts are incorporated with LNAPL lens on top of the flowing groundwater. The study develops conceptual, mathematical and numerical models for simulating the aquifer and LNAPL lens clean-up by a pump-and-treat procedure. The numerical simulations identify the importance of mechanisms of dissolution of the entrapped LNAPL ganglia and the LNAPL lens by films of contact. Clean-up of the LNAPL lens is also affected by mixing in fracture intersections located at the interface LNAPL-groundwater. Dimensionless parameters governing all involved processes are identified and their effects in different ranges are quantified. The clean-up of the LNAPL lens is mainly affected by the mobility number and the fracture segment orientation. These parameters also determine the depth of penetration of the organic solutes into the aquifer. Clean-up of the entrapped LNAPL is mainly affected by the dimensionless interphase mass transfer coefficient. The simulations indicate that at low mobility numbers rates of LNAPL lens clean-up may be faster or slower than clean-up of the LNAPL entrapped within the top layers of the aquifer, depending on the value of the interphase mass transfer coefficient. At high mobility numbers the clean- up rates of the LNAPL lens are always slower than those of the LNAPL entrapped within the top layers of the aquifer.

  13. 21 CFR 71.4 - Samples; additional information.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... respect to the safety of the color additive or the physical or technical effect it produces. The date used for computing the 90-day limit for the purposes of section 721(d)(1) of the act shall be moved...

  14. 21 CFR 71.4 - Samples; additional information.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... respect to the safety of the color additive or the physical or technical effect it produces. The date used for computing the 90-day limit for the purposes of section 721(d)(1) of the act shall be moved...

  15. 52 additional reference population samples for the 55 AISNP panel.

    PubMed

    Pakstis, Andrew J; Haigh, Eva; Cherni, Lotfi; ElGaaied, Amel Ben Ammar; Barton, Alison; Evsanaa, Baigalmaa; Togtokh, Ariunaa; Brissenden, Jane; Roscoe, Janet; Bulbul, Ozlem; Filoglu, Gonul; Gurkan, Cemal; Meiklejohn, Kelly A; Robertson, James M; Li, Cai-Xia; Wei, Yi-Liang; Li, Hui; Soundararajan, Usha; Rajeevan, Haseena; Kidd, Judith R; Kidd, Kenneth K

    2015-11-01

    Ancestry inference for a person using a panel of SNPs depends on the variation of frequencies of those SNPs around the world and the amount of reference data available for calculation/comparison. The Kidd Lab panel of 55 AISNPs has been incorporated in commercial kits by both Life Technologies and Illumina for massively parallel sequencing. Therefore, a larger set of reference populations will be useful for researchers using those kits. We have added reference population allele frequencies for 52 population samples to the 73 previously entered so that there are now allele frequencies publicly available in ALFRED and FROG-kb for a total of 125 population samples. PMID:26355664

  16. [Non-Parametric Analysis of Radiation Risks of Mortality among Chernobyl Clean-Up Workers].

    PubMed

    Gorsky, A I; Maksioutov, M A; Tumanov, K A; Shchukina, N V; Chekin, S Yu; Ivanov, V K

    2016-01-01

    Analysis of the relationship between dose and mortality from cancer and circulation diseases in the cohort of Chernobyl clean-up workers based on the data from the National Radiation and Epidemiological Registry was performed. Medical and dosimetry information on the clean-up workers, males, who got radiation doses from April 26, 1986 to April 26, 1987, which was accumulated from 1992 to 2012, was used for the analysis. The total size of the cohort was 42929 people, 12731 deaths were registered in the cohort, among them 1893 deaths from solid cancers and 5230 deaths were from circulation diseases. An average age of the workers was 39 years in 1992 and the mean dose was 164 mGy. The dose-effect relationship was estimated with the use of non-parametric analysis of survival with regard to concurrence of risks of mortality. The risks were estimated in 6 dose groups of similar size (1-70, 70-130, 130-190, 190-210, 210-230 and.230-1000 mGy). The group "1-70 mGy" was used as control. Estimated dose-effect relationship related to cancers and circulation diseases is described approximately with a linear model, coefficient of determination (the proportion of variability explained by the linear model) for cancers was 23-25% and for circulation diseases - 2-13%. The slope coefficient of the dose-effect relationship normalized to 1 Gy for the ratio of risks for cancers in the linear model was 0.47 (95% CI: -0.77, 1.71), and for circulation diseases it was 0.22 (95% CI: -0.58, 1.02). Risks coefficient (slope coefficient of excess mortality at a dose of 1 Gy) for solid cancers was 1.94 (95% CI: - 3.10, 7.00) x 10(-2) and for circulation diseases it was 0.67 (95% CI: -9.61, 11.00) x 10(-2). 137 deaths from radiation-induced cancers and 47 deaths from circulation diseases were registered during a follow up period. PMID:27534064

  17. [Non-Parametric Analysis of Radiation Risks of Mortality among Chernobyl Clean-Up Workers].

    PubMed

    Gorsky, A I; Maksioutov, M A; Tumanov, K A; Shchukina, N V; Chekin, S Yu; Ivanov, V K

    2016-01-01

    Analysis of the relationship between dose and mortality from cancer and circulation diseases in the cohort of Chernobyl clean-up workers based on the data from the National Radiation and Epidemiological Registry was performed. Medical and dosimetry information on the clean-up workers, males, who got radiation doses from April 26, 1986 to April 26, 1987, which was accumulated from 1992 to 2012, was used for the analysis. The total size of the cohort was 42929 people, 12731 deaths were registered in the cohort, among them 1893 deaths from solid cancers and 5230 deaths were from circulation diseases. An average age of the workers was 39 years in 1992 and the mean dose was 164 mGy. The dose-effect relationship was estimated with the use of non-parametric analysis of survival with regard to concurrence of risks of mortality. The risks were estimated in 6 dose groups of similar size (1-70, 70-130, 130-190, 190-210, 210-230 and.230-1000 mGy). The group "1-70 mGy" was used as control. Estimated dose-effect relationship related to cancers and circulation diseases is described approximately with a linear model, coefficient of determination (the proportion of variability explained by the linear model) for cancers was 23-25% and for circulation diseases - 2-13%. The slope coefficient of the dose-effect relationship normalized to 1 Gy for the ratio of risks for cancers in the linear model was 0.47 (95% CI: -0.77, 1.71), and for circulation diseases it was 0.22 (95% CI: -0.58, 1.02). Risks coefficient (slope coefficient of excess mortality at a dose of 1 Gy) for solid cancers was 1.94 (95% CI: - 3.10, 7.00) x 10(-2) and for circulation diseases it was 0.67 (95% CI: -9.61, 11.00) x 10(-2). 137 deaths from radiation-induced cancers and 47 deaths from circulation diseases were registered during a follow up period.

  18. Terminating Safeguards on Excess Special Nuclear Material: Defense TRU Waste Clean-up and Nonproliferation - 12426

    SciTech Connect

    Hayes, Timothy; Nelson, Roger

    2012-07-01

    The Department of Energy (DOE) and the National Nuclear Security Administration (NNSA) manages defense nuclear material that has been determined to be excess to programmatic needs and declared waste. When these wastes contain plutonium, they almost always meet the definition of defense transuranic (TRU) waste and are thus eligible for disposal at the Waste Isolation Pilot Plant (WIPP). The DOE operates the WIPP in a manner that physical protections for attractiveness level D or higher special nuclear material (SNM) are not the normal operating condition. Therefore, there is currently a requirement to terminate safeguards before disposal of these wastes at the WIPP. Presented are the processes used to terminate safeguards, lessons learned during the termination process, and how these approaches might be useful for future defense TRU waste needing safeguards termination prior to shipment and disposal at the WIPP. Also described is a new criticality control container, which will increase the amount of fissile material that can be loaded per container, and how it will save significant taxpayer dollars. Retrieval, compliant packaging and shipment of retrievably stored legacy TRU waste has dominated disposal operations at WIPP since it began operations 12 years ago. But because most of this legacy waste has successfully been emplaced in WIPP, the TRU waste clean-up focus is turning to newly-generated TRU materials. A major component will be transuranic SNM, currently managed in safeguards-protected vaults around the weapons complex. As DOE and NNSA continue to consolidate and shrink the weapons complex footprint, it is expected that significant quantities of transuranic SNM will be declared surplus to the nation's needs. Safeguards termination of SNM varies due to the wide range of attractiveness level of the potential material that may be directly discarded as waste. To enhance the efficiency of shipping waste with high TRU fissile content to WIPP, DOE designed an over

  19. Diethylaminoethyl-cellulose clean-up of a large volume naphthenic acid extract.

    PubMed

    Frank, Richard A; Kavanagh, Richard; Burnison, B Kent; Headley, John V; Peru, Kerry M; Der Kraak, Glen Van; Solomon, Keith R

    2006-08-01

    The Athabasca oil sands of Alberta, Canada contain an estimated 174 billion barrels of bitumen. During oil sands refining processes, an extraction tailings mixture is produced that has been reported as toxic to aquatic organisms and is therefore collected in settling ponds on site. Investigation into the toxicity of these tailings pond waters has identified naphthenic acids (NAs) and their sodium salts as the major toxic components, and a multi-year study has been initiated to identify the principal toxic components within NA mixtures. Future toxicity studies require a large volume of a NA mixture, however, a well-defined bulk extraction technique is not available. This study investigated the use of a weak anion exchanger, diethylaminoethyl-cellulose (DEAE-cellulose), to remove humic-like material present after collecting the organic acid fraction of oil sands tailings pond water. The NA extraction and clean-up procedure proved to be a fast and efficient method to process large volumes of tailings pond water, providing an extraction efficiency of 41.2%. The resulting concentrated NA solution had a composition that differed somewhat from oil sands fresh tailings, with a reduction in the abundance of lower molecular weight NAs being the most significant difference. This reduction was mainly due to the initial acidification of tailings pond water. The DEAE-cellulose treatment had only a minor effect on the NA concentration, no noticeable effect on the NA fingerprint, and no significant effect on the mixture toxicity towards Vibrio fischeri. PMID:16469358

  20. Hanford tank clean up: A guide to understanding the technical issues

    SciTech Connect

    Gephart, R.E.; Lundgren, R.E.

    1995-12-31

    One of the most difficult technical challenges in cleaning up the US Department of Energy`s (DOE) Hanford Site in southeast Washington State will be to process the radioactive and chemically complex waste found in the Site`s 177 underground storage tanks. Solid, liquid, and sludge-like wastes are contained in 149 single- and 28 double-shelled steel tanks. These wastes contain about one half of the curies of radioactivity and mass of hazardous chemicals found on the Hanford Site. Therefore, Hanford cleanup means tank cleanup. Safely removing the waste from the tanks, separating radioactive elements from inert chemicals, and creating a final waste form for disposal will require the use of our nation`s best available technology coupled with scientific advances, and an extraordinary commitment by all involved. The purpose of this guide is to inform the reader about critical issues facing tank cleanup. It is written as an information resource for the general reader as well as the technically trained person wanting to gain a basic understanding about the waste in Hanford`s tanks -- how the waste was created, what is in the waste, how it is stored, and what are the key technical issues facing tank cleanup. Access to information is key to better understanding the issues and more knowledgeably participating in cleanup decisions. This guide provides such information without promoting a given cleanup approach or technology use.

  1. Environmental roundup/company wins reimbursement for clean up of oil spill

    SciTech Connect

    Austin, J.D.

    1980-11-01

    The U.S. Court of Claims has awarded Union Petroleum Corp. almost $100,000 to reimburse the expenses it had incurred in cleaning up an oil spill caused by vandals at Union's oil terminal and distribution facility near Revere, Massachusetts on 4/5-6/75. The court ruled that Union had established all of the elements required by the Clean Water Act to recover its reasonable expenses. Among these elements were the immediate notification of the U.S. Coast Guard and a spill cleanup company upon the discovery of the spill and discharge of some of the approximately 60,000 gal of No. 6 fuel oil into the Chelsea Creek on 4/6/75; the adequate security precautions at Union's facilities, including a spill containment system and an oil separator to prevent oil from being discharged into the creek; and the responsibility of a third party for the discharge. The court also praised the voluntary action taken by Union, since the two railroad cars from which the No. 6 fuel oil had been discharged were not owned or operated by Union.

  2. Diving behaviour of wildlife impacted by an oil spill: A clean-up and rehabilitation success?

    PubMed

    Chilvers, B L; Morgan, K M; Finlayson, G; Sievwright, K A

    2015-11-15

    The value of rehabilitating oiled wildlife is an on-going global debate. On October 5, 2011, the cargo vessel C/V Rena grounded on Astrolabe Reef, New Zealand (NZ), spilling over 300 tonnes of heavy fuel oil. As part of the Rena oil spill response, 383 little blue penguins (LBP, Eudyptula minor) were captured, cleaned, rehabilitated and released back into a cleaned environment. This research investigates foraging behaviour changes due either to the oil spill or by the rehabilitation process by comparing the diving behaviour of rehabilitated (n=8) and non-rehabilitated (n=6) LBPs and with LBP populations throughout NZ. Stabile isotope analysis of feathers was also used to investigate diet. There were no foraging behaviour differences between rehabilitated and non-rehabilitated LBPs and the overall diving behaviour of these LBPs have similar, if not less energetic, foraging behaviour than other LBPs in NZ. This suggests the rehabilitation process and clean-up undertaken after the Rena appears effective and helps justify the rehabilitation of oiled wildlife across the world.

  3. [The assessment of remote cytogenetic effects in clean up workers of Chernobyl accident].

    PubMed

    Golub, E V

    2009-01-01

    Cytogenetic study cohort of the liquidators of the consequences of Chernobyl accident over 4-6 years after clean-up working in the alienation zone was carried out by conventional method. For The results of study liquidators cohort of 1986-1987 years have shown decreasing the frequency of cells with unstable chromosome aberrations for 25-30% per each year of examination. The frequency of chromosomal and chromatid-type aberrations have been also decreasing. The increasing of frequency radiation markers (dicentrics and rings) was observed for liquidators who worked in Chernobyl in 1988 year. Significant distinctions on other cytogenetics parameters as well as for liquidators who worked in Chernobyl in 1989 year were not observed perhaps of small number of examined cohorts. Nevertheless level of chromosome aberrations observed in remote post radiation period was significantly higher then controls that may be caused by radiation-induced genome instability. Obtained data show the importance of cytogenetic examination of that cohort for estimation and the prognosis the risk of delayed negative consequences of exposure.

  4. Diving behaviour of wildlife impacted by an oil spill: A clean-up and rehabilitation success?

    PubMed

    Chilvers, B L; Morgan, K M; Finlayson, G; Sievwright, K A

    2015-11-15

    The value of rehabilitating oiled wildlife is an on-going global debate. On October 5, 2011, the cargo vessel C/V Rena grounded on Astrolabe Reef, New Zealand (NZ), spilling over 300 tonnes of heavy fuel oil. As part of the Rena oil spill response, 383 little blue penguins (LBP, Eudyptula minor) were captured, cleaned, rehabilitated and released back into a cleaned environment. This research investigates foraging behaviour changes due either to the oil spill or by the rehabilitation process by comparing the diving behaviour of rehabilitated (n=8) and non-rehabilitated (n=6) LBPs and with LBP populations throughout NZ. Stabile isotope analysis of feathers was also used to investigate diet. There were no foraging behaviour differences between rehabilitated and non-rehabilitated LBPs and the overall diving behaviour of these LBPs have similar, if not less energetic, foraging behaviour than other LBPs in NZ. This suggests the rehabilitation process and clean-up undertaken after the Rena appears effective and helps justify the rehabilitation of oiled wildlife across the world. PMID:26424224

  5. A solid-phase extraction procedure for the clean-up of thiram from aqueous solutions containing high concentrations of humic substances.

    PubMed

    Filipe, O M S; Vidal, M M; Duarte, A C; Santos, E B H

    2007-05-15

    A simple solid-phase extraction (SPE) procedure with an octadecyl bonded phase silica (C(18)) was developed for clean-up of the fungicide thiram from aqueous solutions containing high concentrations of humic substances, for future studies of thiram adsorption onto solid humic substances or soils. Suspensions of humic acids and soil, in aqueous 0.01M CaCl(2) solution, were prepared and used as samples. These extracts were spiked with thiram and immediately applied to a C(18)-SPE cartridge. Thiram was eluted with chloroform and its concentration measured by spectrophotometry at 283nm. Non-spiked aqueous extracts (blanks) and a control sample of thiram in 0.01M CaCl(2) aqueous solution were also prepared and submitted to the same SPE procedure. The results show that humic substances are extensively retained by the C(18) cartridge but are not eluted with CHCl(3). Recoveries of 100-104% were obtained for thiram in the presence of humic substances. The SPE procedure described in this work is an efficient clean-up step to remove the interference of humic substances absorbance and to be coupled to any spectrophotometric or HPLC-UV method, usually used for thiram analysis in food extracts.

  6. Evaluation of three somatic genetic biomarkers as indicators of low dose radiation effects in clean-up workers of the Chernobyl nuclear reactor accident.

    PubMed

    Jones, I M; Tucker, J D; Langlois, R G; Mendelsohn, M L; Pleshanov, P; Nelson, D O

    2001-01-01

    The goals of this study were to assess three biomarkers of genetic effect for their individual and collective ability to detect and estimate radiation exposure in Russian Chernobyl clean-up workers. Work assignments were planned to limit dose to 0.25 Gy. The three biomarkers employed were chromosome translocations detectcd in lynmphocytes by florescence in situ hybridisation (FISH), and mutation at two genes, glycophorin A (GPA) in red blood cells detected by flow cytometry and hypoxanthine phosphoribosyltransferase (HPRT) in lymphocytes detected by selective cell culture. Samples were Obtained from 1992 to 2000. The time between exposure at Chernobyl and sample acquisition was > or =5 years. The lymphocyte assays detected an elevation over controls in average outcomes it clean-up workers: translocation rates were 46% higher when adjusted for age and smoking and HPRT mutant frequencies were were 16% higher when adjusted for age. The G PA assay did not detect an exposure effect. The results indicate that measuring frequency of translocations by FISH is preferred for low dose radiation, retrospective biochemistry.

  7. Determination of diphenamide, napropamide and metolachlor in tobacco by gel permeation chromatographic clean-up and high performance liquid chromatography.

    PubMed

    Liu, Hongxia; Dang, Yuanlin; Zhang, Shusheng; Liu, Huimin; Qu, Lingbo; Liao, Xincheng; Zhao, Yufen; Wu, Yangjie

    2005-05-01

    Diphenamide, napropamide and metolachlor (FIG. 1) are selective, pre-emergence arylamide herbicides used to control the growth of annual grasses and broadleaf weeds in a variety of fields, e.g. fruit trees, nuts, corns, green crops, etc. They possess high activity and moderate toxicity. For food and environment safety, the detailed investigations on their residues and metabolism are very important. Diphenamide, napropamide and metolachlor in the pesticide products, serum, urine, soil, environmental water, fruits and wine have been widely analyzed by ELISA, fluorescence, phosphorescence, capillary electrophoresis, high performance liquid chromatography (HPLC), gas chromatography(GC) and GC mass spectrometry (GC-MS). However, to our knowledge, simultaneous residue analysis of diphenamide, napropamide and metolachlor in tobacco samples has not been extensively documented. Tobacco is greatly consumed by smokers throughout the world. The pesticide residue in tobaccos might be potentially harmful to smokers' health. With this in mind the residue determination and control of diphenamide, napropamide and metolachlor in the tobacco leaves are very important for tobacco products and consumers. For these three herbicides, the tolerable maximum residue limits (MRLs) have been limited ranging from 0.05 (for tobacco products) to 5 mg/kg (for tobacco leaves) in different European countries. For the complex tobacco samples, the GC and HPLC with UV detection suffer from matrix interference making quantification and identification of these herbicides difficult. In such cases the removal of the matrix effects and identification of the target compounds are of great importance. The present work reports the extraction and clean up procedures, as well as, the chromatographic conditions developed for the simultaneous determination of diphenamide, napropamide and metolachlor residues in the fluecured tobacco leaves, from the different sources using HPLC-UV method. PMID:16477944

  8. Understanding 'clean-up' of III-V native oxides during atomic layer deposition using bulk first principles models.

    PubMed

    Klejna, Sylwia; Elliott, Simon D

    2011-09-01

    The use of III-V materials as the channel in future transistor devices is dependent on removing the deleterious native oxides from their surface before deposition of a gate dielectric. Trimethylaluminium has been found to achieve in situ 'clean-up' of the oxides of GaAs and InGaAs before atomic layer deposition (ALD) of alumina. Here we propose six reaction mechanisms for 'clean-up,' featuring exchange of ligands between surface atoms, reduction of arsenic oxide by methyl groups and desorption of various products. We use first principles Density Functional Theory (DFT) to determine which mechanistic path is thermodynamically favoured based on models of the bulk oxides and gas-phase products. We therefore predict that 'clean-up' of arsenic oxides mostly produces As4 gas. Most C is predicted to form C2H6 but with some C2H4, CH4 and H2O. An alternative pathway is non-redox ligand exchange, which allows non-reducible oxides to be cleaned-up.

  9. EVALUATION OF DEMONSTRATED AND EMERGING TECHNOLOGIES FOR THE TREATMENT AND CLEAN-UP OF CONTAMINATED LAND AND GROUNDWATER

    EPA Science Inventory

    This article provides an overview of the Phase III Pilot Study on the Evaluation of Demonstrated and Emerging Technologies for Treatment and Clean Up of Contaminated Land and Groundwater. It also contains the key conclusions of the Pilot Study and recommendations for further act...

  10. Determination of pesticides in edible oils by liquid chromatography-tandem mass spectrometry employing new generation materials for dispersive solid phase extraction clean-up.

    PubMed

    Dias, Jonatan V; Cutillas, Victor; Lozano, Ana; Pizzutti, Ionara R; Fernández-Alba, Amadeo R

    2016-09-01

    The goal of this work was to evaluate the efficiency of several sorbents on removal fats from edible oils (olive, soya and sunflower) during the clean-up step for posterior determination of 165 pesticides by UHPLC-QqQ-MS/MS system. The extraction procedure employed in this work was the citrate version of QuEChERS method followed by a step of freezing out with dry ice and clean-up evaluation using i) PSA with magnesium sulfate (d-SPE); ii) magnesium sulfate and Z-sep sorbent (d-SPE); iii) Z-sep (column SPE) and iv) Agilent Bond Elut QuEChERS Enhanced Matrix Removal-Lipid (EMR-Lipid). After evaluation of the recovery results at 10, 20 and 50μgkg(-1), the EMR-Lipid showed important advantages comparing to the other sorbents evaluated, such as better recovery rates and RSD%. The method was validated at the three concentrations described above. Analytical curves linearity was evaluated by spiking blank oil samples at 10, 20, 50, 100 and 500μgkg(-1). The method demonstrated good recoveries values between the acceptable range of 70-120% and RSD%<20 for most of evaluated pesticides. In order to evaluate the performance of the method, this same procedure was employed to other oils such as soya and sunflower with very good results.

  11. [Simultaneous determination of zeranols and chloramphenicol in foodstuffs of animal origin by combination immunoaffinity column clean-up and liquid chromatography-tandem mass spectrometry].

    PubMed

    Wang, Qing; Wang, Guomin; Xi, Cunxian; Li, Xianliang; Chen, Dongdong; Tang, Bobin; Zhang, Lei; Zhao, Hua

    2014-06-01

    A combination immunoaffinity column (IAC-CZ) clean-up and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analytical method was successfully developed for zearalenol, beta-zearalenol and zearalenone) and chloramphenicol (CAP) in foodstuffs of animal origin. The samples (fish, liver, milk and honey) were enzymatically digested by beta-glucuronidase/sulfatase for about 16 h and then extracted with ether. The extracts were evaporated to dryness and then the residues were dissolved by 1.0 mL of 50% acetonitrile solution. After filtered and diluted with PBS buffer, the reconstituted solution were cleaned-up with a IAC-CZ and then analyzed by LC-MS/MS in multiple reaction monitoring (MRM) mode. The chromatographic separation was performed on a Shimadzu Shim-pack VP-ODS column with gradient elution by acetonitrile and 2 mmol/L ammonium acetate solution. The detection was carried out by electrospray negative ionization mass spectrometry in MRM mode. The proposed method was validated by the limit of detection (0.04-0.10 microg/kg), linearity (R2 > or = 0.999 0), average recoveries (70.9%-95.6%) and precisions (2.0% - 11.8%). The developed method is reliable, sensitive and has good applicability. The combination immunoaffinity column was proved to be an effective pretreatment technique to decrease the matrix effect, and it met the requirements of residue analysis of co-occurring zeranols and chloramphenicol. PMID:25269264

  12. Determination of fusarium mycotoxins in wheat, maize and animal feed using on-line clean-up with high resolution mass spectrometry.

    PubMed

    Ates, E; Mittendorf, K; Stroka, J; Senyuva, H

    2013-01-01

    An automated method involving on-line clean-up and analytical separation in a single run using TurboFlow™ reversed phase liquid chromatography coupled to a high resolution mass spectrometer has been developed for the simultaneous determination of deoxynivalenol, T2 toxin, HT2 toxin, zearalenone and fumonisins B1 and B2 in maize, wheat and animal feed. Detection was performed in full scan mode at a resolution of R = 100,000 full width at half maximum with high energy collision cell dissociation for the determination of fragment ions with a mass accuracy below 5 ppm. The extract from homogenised samples, after blending with a 0.1% aqueous mixture of 0.1% formic acid/acetonitrile (43:57) for 45 min, was injected directly onto the TurboFlow™ (TLX) column for automated on-line clean-up followed by analytical separation and accurate mass detection. The TurboFlow™ column enabled specific binding of target mycotoxins, whereas higher molecular weight compounds, like fats, proteins and other interferences with different chemical properties, were removed to waste. Single laboratory method validation was performed by spiking blank materials with mycotoxin standards. The recovery and repeatability was determined by spiking at three concentration levels (50, 100 and 200% of legislative limits) with six replicates. Average recovery, relative standard deviation and intermediate precision values were 71 to 120%, 1 to 19% and 4 to 19%, respectively. The method accuracy was confirmed with certified reference materials and participation in proficiency testing.

  13. [Simultaneous determination of zeranols and chloramphenicol in foodstuffs of animal origin by combination immunoaffinity column clean-up and liquid chromatography-tandem mass spectrometry].

    PubMed

    Wang, Qing; Wang, Guomin; Xi, Cunxian; Li, Xianliang; Chen, Dongdong; Tang, Bobin; Zhang, Lei; Zhao, Hua

    2014-06-01

    A combination immunoaffinity column (IAC-CZ) clean-up and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analytical method was successfully developed for zearalenol, beta-zearalenol and zearalenone) and chloramphenicol (CAP) in foodstuffs of animal origin. The samples (fish, liver, milk and honey) were enzymatically digested by beta-glucuronidase/sulfatase for about 16 h and then extracted with ether. The extracts were evaporated to dryness and then the residues were dissolved by 1.0 mL of 50% acetonitrile solution. After filtered and diluted with PBS buffer, the reconstituted solution were cleaned-up with a IAC-CZ and then analyzed by LC-MS/MS in multiple reaction monitoring (MRM) mode. The chromatographic separation was performed on a Shimadzu Shim-pack VP-ODS column with gradient elution by acetonitrile and 2 mmol/L ammonium acetate solution. The detection was carried out by electrospray negative ionization mass spectrometry in MRM mode. The proposed method was validated by the limit of detection (0.04-0.10 microg/kg), linearity (R2 > or = 0.999 0), average recoveries (70.9%-95.6%) and precisions (2.0% - 11.8%). The developed method is reliable, sensitive and has good applicability. The combination immunoaffinity column was proved to be an effective pretreatment technique to decrease the matrix effect, and it met the requirements of residue analysis of co-occurring zeranols and chloramphenicol.

  14. Determination of pesticides in edible oils by liquid chromatography-tandem mass spectrometry employing new generation materials for dispersive solid phase extraction clean-up.

    PubMed

    Dias, Jonatan V; Cutillas, Victor; Lozano, Ana; Pizzutti, Ionara R; Fernández-Alba, Amadeo R

    2016-09-01

    The goal of this work was to evaluate the efficiency of several sorbents on removal fats from edible oils (olive, soya and sunflower) during the clean-up step for posterior determination of 165 pesticides by UHPLC-QqQ-MS/MS system. The extraction procedure employed in this work was the citrate version of QuEChERS method followed by a step of freezing out with dry ice and clean-up evaluation using i) PSA with magnesium sulfate (d-SPE); ii) magnesium sulfate and Z-sep sorbent (d-SPE); iii) Z-sep (column SPE) and iv) Agilent Bond Elut QuEChERS Enhanced Matrix Removal-Lipid (EMR-Lipid). After evaluation of the recovery results at 10, 20 and 50μgkg(-1), the EMR-Lipid showed important advantages comparing to the other sorbents evaluated, such as better recovery rates and RSD%. The method was validated at the three concentrations described above. Analytical curves linearity was evaluated by spiking blank oil samples at 10, 20, 50, 100 and 500μgkg(-1). The method demonstrated good recoveries values between the acceptable range of 70-120% and RSD%<20 for most of evaluated pesticides. In order to evaluate the performance of the method, this same procedure was employed to other oils such as soya and sunflower with very good results. PMID:27507727

  15. Innovative Integration of Decommissioning and Deactivation Program with Soil-Groundwater Clean Up Program Has Positive Results on Budget and Schedule: A Case Study

    SciTech Connect

    Schappell, B; Rucker, G

    2007-07-25

    An innovative approach to integrate the activities of a decommissioning and deactivation program (D&D) with a soil-groundwater clean up program has had significant positive results saving both money and time at the Department of Energy's Savannah River Site. The accomplishments that have been achieved by the combining the two programs have been remarkable including significant cost savings, economies of scale for sampling and document generation, and alignment of common objectives. Because of the coordination of both activities area-wide ''end states'' can be formulated and be consistent with the customers' cleanup goals and federal regulations. This coordinates and aligns both the environmental clean up and D&D objectives because each must be addressed simultaneously and comprehensively. In this respect, resources from both organizations can be pooled to take advantage of the strengths of each. The new approach allows more efficient use of lean financial resources and optimizes workforce activities to attain the common objectives while being more cost effective, more protective of the environment, and optimizing the use existing resources.

  16. Ultrasonic extraction of veterinary antibiotics from soils and pig slurry with SPE clean-up and LC-UV and fluorescence detection.

    PubMed

    Blackwell, Paul A; Holten Lützhøft, Hans-Christian; Ma, Hai-Ping; Halling-Sørensen, Bent; Boxall, Alistair B A; Kay, Paul

    2004-11-15

    A simple and rapid analytical method is presented in which the three veterinary antibiotics oxytetracycline (OTC), sulfachloropyridazine (SCP) and tylosin (TYL) are simultaneously extracted and determined in four different soils. Extractions were carried out by a combination of ultrasonic agitation and vortex mixing using a mixture of methanol, EDTA and McIlvaine buffer at pH 7 as the extractant solution. The extracts were then cleaned-up by a tandem solid phase extraction (SPE) method using an Isolute SAX anion exchange cartridge to remove natural organic matter and an Oasis HLB polymeric cartridge to retain the study compounds. Analysis was by HPLC-UV with additional fluorescence detection for SCP. Recoveries were in the range 68-85% for SCP in all soil types, 58-75% for OTC in sandy soils, 27-51% for OTC in clay containing soils, 74-105% for TYL and 47-61% in a clay soil. OTC and SCP were also extracted from liquid pig manure using a mixture of EDTA and McIlvaine buffer at pH 7 with ultrasonic agitation and vortex mixing with SPE clean-up and HPLC-UV analysis. Recoveries were greater than 77% and 58% for OTC and SCP, respectively. Limits of detection were 18mugkg(-1) for OTC and SCP and 40mugkg(-1) for TYL in soils and 70mugL(-1) for OTC and 140mugL(-1) for SCP in pig slurry. PMID:18969712

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

    PubMed

    Oellig, Claudia

    2016-05-01

    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. PMID:27059398

  18. Clinical aspects of the health disturbances in Chernobyl Nuclear Power Plant accident clean-up workers (liquidators) from Latvia.

    PubMed

    Eglite, M E; Zvagule, T J; Rainsford, K D; Reste, J D; Curbakova, E V; Kurjane, N N

    2009-06-01

    The health status of some 6,000 workers from Latvia who went to clean-up the Chernobyl Nuclear Power Plant (CNPP) site following the explosion on 26 April 1986 has been analyzed. The data on these workers have been recorded in the Latvian State Register of Occupational disease patients and people exposed to ionizing radiation due to Chernobyl NPP accident (Latvian State Register) that was established in 1994. From these data, estimates have been made of external ionizing radiation to which these workers were exposed together with observations on the impact of exposure to heavy metals (especially lead and zinc) and radioactive isotopes released during the reactor 'meltdown'. These factors along with psycho-emotional and social-economic stresses account for a marked excess of mortality and morbidity in the group of CNPP accident clean-up workers compared with that of the non-exposed normal Latvian population adjusted for age and sex. The number of diseases or conditions in the CNPP accident clean-up workers has progressively risen from an average of 1.3 in 1986 to 10.9 in 2007. This exceeds for the Latvian population when adjusted for age and sex. The most serious conditions affect the nervous, digestive, respiratory, cardiovascular, endocrine (especially thyroid) and immunological systems. While the morbidity associated with diseases of the respiratory and digestive systems has decreased in recent years that in the other systems is increasing. In recent years, there has been an increased occurrence of cancers affecting the thyroid, prostate and stomach. Clinical and laboratory investigations suggest that surviving CNPP accident clean-up workers exhibit signs of immuno-inflammatory reactions causing premature aging with evidence of autoimmune diseases and immunological deficiencies or abnormalities. It is suggested that the CNPP accident clean-up workers may have a specific syndrome, the 'Chernobyl post-radiation neurosomatic polypathy', due to sustained oxidant

  19. Policies to clean up toxic industrial contaminated sites of Gela and Priolo: a cost-benefit analysis

    PubMed Central

    2011-01-01

    Background Cost-benefit analysis is a transparent tool to inform policy makers about the potential effect of regulatory interventions, nevertheless its use to evaluate clean-up interventions in polluted industrial sites is limited. The two industrial areas of Gela and Priolo in Italy were declared "at high risk of environmental crisis" in 1990. Since then little has been done to clean the polluted sites and reduce the health outcomes attributable to pollution exposure. This study, aims to quantify the monetary benefits resulting from clean-up interventions in the contaminated sites of Gela and Priolo. Methods A damage function approach was used to estimate the number of health outcomes attributable to industrial pollution exposure. Extensive one way analyses and probabilistic analyses were conducted to investigate the sensitivity of results to different model assumptions. Results It has been estimated that, on average, 47 cases of premature death, 281 cases of cancer and 2,702 cases of non-cancer hospital admission could be avoided each year by removing environmental exposure in these two areas. Assuming a 20 year cessation lag and a 4% discount rate we calculate that the potential monetary benefit of removing industrial pollution is €3,592 million in Priolo and €6,639 million in Gela. Conclusions Given the annual number of health outcomes attributable to pollution exposure the effective clean-up of Gela and Priolo should be prioritised. This study suggests that clean-up policies costing up to €6,639 million in Gela and €3,592 million in Priolo would be cost beneficial. These two amounts are notably higher than the funds allocated thus far to clean up the two sites, €127.4 million in Gela and €774.5 million in Priolo, implying that further economic investments - even considerable ones - could still prove cost beneficial. PMID:21797993

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

    PubMed

    Oellig, Claudia

    2016-05-01

    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.

  1. Oak Ridge Cleanup Vision: Moving to the Future by Cleaning Up the Past - 13291

    SciTech Connect

    Cange, Susan M.; Wieland, Christopher C.; DePaoli, Susan M.

    2013-07-01

    received buy-in from the leadership in Headquarters, the regulators, and the community. Issues EM was facing in 2009 are presented. Resulting lessons learned and subsequent changes that the Office has gone through in the past several years in order to improve performance in the safe execution of work, relationships with external stakeholders, and communications both internally and externally are discussed. Results of these efforts are provided as a summary of Program accomplishments, including a strong focus on the future. EM's motto, Moving to the Future by Cleaning up the Past, will be demonstrated through the Program's mission, which includes protecting the region's health and environment; ensuring the continuation of ongoing vital missions being conducted by DOE on the Oak Ridge Reservation; and making clean land available for future use at all three sites, with a near-term focus on Re-industrialization of ETTP. (authors)

  2. Rapid determination of 88 veterinary drug residues in milk using automated TurborFlow online clean-up mode coupled to liquid chromatography-tandem mass spectrometry.

    PubMed

    Zhu, Wei-xia; Yang, Ji-zhou; Wang, Zhao-xing; Wang, Cai-juan; Liu, Ya-feng; Zhang, Li

    2016-02-01

    A novel method based on TurborFlow online solid phase extraction (SPE) combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been established for simultaneous screening and confirmation of 88 wide-range veterinary drugs belonging to eight families (20 sulfonamides, 7 macrolides, 15 quinolones, 8 penicillins, 13 benzimidazoles, 4 tetracyclines, 2 sedatives, and 19 hormones) in milk. The preparation method consists of sample dilution and ultrasonic extraction, followed by an automated turbulent flow cyclone chromatography sample clean-up system. The detection was achieved in selected reaction monitoring mode (SRM). The total run time was within 39 min, including automated extraction, analytical chromatography and re-equilibration of the turboflow system. The optimization of different experimental parameters including extraction, purification, separation, and detection were evaluated separately in this study. The developed method was validated and good performing characteristics were obtained. The linear regression coefficients (R(2)) of matrix-match calibration standard curves established for quantification were higher than 0.9930. The limits of detection (LOD) were in the range of 0.2-2.0 μg/kg given by signal-noise ratio ≥3 (S/N) and the limits of quantification (LOQ, S/N≥10) ranged between 0.5 μg/kg and 10 μg/kg. Average recoveries of spiked target compounds with different levels were between 63.1% and 117.4%, with percentage relative standard deviations (RSD) in the range of 3.3-17.6%. The results indicated that the developed method has great potential for the routine laboratory analysis of large numbers of samples on measuring different classes of compounds. In comparison to traditional procedures, the automated sample clean-up ensures rapid, effective, sensitive analyses of veterinary drugs in milk.

  3. Building upon Historical Competencies: Next-generation Clean-up Technologies for World-Wide Application - 13368

    SciTech Connect

    Guevara, K.C.; Fellinger, A.P.; Aylward, R.S.; Griffin, J.C.; Hyatt, J.E.; Bush, S.R.

    2013-07-01

    The Department of Energy's Savannah River Site has a 60-year history of successfully operating nuclear facilities and cleaning up the nuclear legacy of the Cold War era through the processing of radioactive and otherwise hazardous wastes, remediation of contaminated soil and groundwater, management of nuclear materials, and deactivation and decommissioning of excess facilities. SRS recently unveiled its Enterprise.SRS (E.SRS) strategic vision to identify and facilitate application of the historical competencies of the site to current and future national and global challenges. E.SRS initiatives such as the initiative to Develop and Demonstrate Next generation Clean-up Technologies seek timely and mutually beneficial engagements with entities around the country and the world. One such ongoing engagement is with government and industry in Japan in the recovery from the devastation of the Fukushima Daiichi Nuclear Power Station. (authors)

  4. Technical approaches to characterizing and cleaning up iron and steel mill sites under the brownfields initiative. Final report

    SciTech Connect

    1998-12-01

    EPA has developed this guide to provide decision-makers, such as city planners, private sector developers, and other involved in redeveloping brownfields, with a better understanding of the technical issues involved in assessing and cleaning up iron and steel mill sites so they can make the most informed decisions possible. This overview of the technical process involved in assessing and cleaning up brownfields sites can assist planners in making decisions at various stages of the project. An understanding of land use and industrial processes conducted in the past at a site can help the planner to conceptualize the site and identify likely areas of contamination that may require cleanup. Numerous resources are suggested to facilitate characterization of the site and consideration of cleanup technologies.

  5. Ultrasonic extraction followed by a novel filtration and clean-up device for screening of some polyphenols in tobaccos.

    PubMed

    Gu, Xungang; Cai, Jibao; Yang, Jun; Su, Qingde

    2005-02-01

    A simple and efficient HPLC method using a diode array detector (DAD) was developed for simultaneous determination of six polyphenols in tobaccos. Ultrasonic extraction was employed at 25 degrees C to extract the polyphenols present in tobaccos into anhydrous methanol. A novel filtration device linked to a clean-up cartridge was designed for simultaneous extract filtration and clean-up. Optimized HPLC-DAD analysis, with multi-wavelength detection, was used for determination of the polyphenols. Because the content of some of the polyphenols is too low to be quantified directly, a concentration step was necessary. Anhydrous methanol was employed for extraction of the polyphenols because of its high extraction efficiency and its low boiling point in the concentration step. Using the proposed method, six polyphenols were quantified in tobaccos (Nicotina tobaccum L.).

  6. Methodology and data used for estimating the complex-wide impacts of alternative environmental restoration clean-up goals

    SciTech Connect

    Shay, M.R.; Short, S.M.; Stiles, D.L.

    1994-03-01

    This paper describes the methodologies and data used for estimating the complex-wide impacts of alternative strategies for conducting remediation of all DOE sites and facilities, but does not address issues relating to Waste Management capabilities. Clean-up strategies and their corresponding goals for contaminated media may be driven by concentration-based regulatory standards, land-use standards (e.g., residential, industrial, wild life reserve, or totally restricted), risk-based standards, or other standards determined through stakeholder input. Strategies implemented to achieve these goals usually require the deployment of (a) clean-up technologies to destroy, remove, or contain the contaminants of concern; (b) institutional controls to prevent potential receptors from coming into contact with the contaminants; or (c) a combination of the above.

  7. Variable-Sweep Transition Flight Experiment (VSTFE): Stability code development and clean-up glove data analysis

    NASA Technical Reports Server (NTRS)

    Rozendaal, Roger A.

    1987-01-01

    The primary objective of the Variable Sweep Transition Flight Experiment (VSTFE) was to establish an improved swept wing transition criterion. The development of the Unified Stability System gave a way of quickly examining disturbance growth for a wide variety of laminar boundary layers. The disturbance growth traces shown are too scattered to define a transition criteria to replace the F-111 data band, which has been used successfully to design NLF gloves. Still, a careful review of the clean-up glove data may yield cases for which the transition location is known more accurately. Liquid crystal photographs of the clean-up glove show much spanwise variation in the transition front for some conditions, and this further complicates the analyses. Several high quality cases are needed in which the transition front is well defined and at a relatively constant chordwise station.

  8. 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

    2010-07-01

    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. PMID:20627308

  9. On-line clean-up of pressurized liquid extracts for the determination of polychlorinated biphenyls in feedingstuffs and food matrices using gas chromatography-mass spectrometry.

    PubMed

    Müller, A; Björklund, E; von Holst, C

    2001-08-01

    This paper describes a fast and simple pressurized liquid extraction method for the determination of polychlorinated biphenyls (PCBs) in feedingstuffs and food matrices. The method is based on a simultaneous extraction/clean-up step requiring a minimum of sample handling. The final analysis was performed with gas chromatography-mass spectrometry. Seven PCBs (28, 52, 101, 118, 138, 153 and 180) were analyzed, all of which are indicator congeners that, according to European legislation should be included in the analytical monitoring program. The extracted matrices were spiked feed for poultry and two certified reference materials naturally contaminated with PCBs (cod-liver oil and milk powder), which showed excellent conformity with certified data.

  10. Novel fracture technology proves marginal Viking prospect economic, part II: Well clean-up, flowback and testing

    SciTech Connect

    Haidar, S.; Rylance, M.; Tybero, G.

    1996-12-31

    Having completed both fracture treatments as discussed in a companion paper, this paper continues on to describe the post fracture shut-in, clean-up and well testing operations that took place on the Viking Wx exploration well 49/17-12. These operations involved the removal of Resin Coated Proppant (RCP) from the wellbore, via Coiled Tubing (CT), through the use of a specially designed jetting nozzle. The RCP pack stability at a concentration of 3.0 lb/ft{sup 2} (as per planned design) had already been tested in a flowback cell. The use of a Surface Read-Out (SRO) gauge, combined with gas, water and proppant flow rates as well as the viscosity of fracturing fluids returns, enabled real time calculation of the drag forces, on the proppant pack, during clean-up. The flow rate, in the field, was controlled such that the calculated drag forces remained below those observed in the laboratory. Following the clean-up a flow and build-up test was conducted, to evaluate the fracture half length and fracture conductivity, from which a Pseudo-radial skin was calculated. The Non-Darcy effects in the fracture were also evaluated, and finally the short term and long term well deliverabilities were assessed.

  11. Simultaneous determination of four aflatoxins and ochratoxin A in ginger and related products by HPLC with fluorescence detection after immunoaffinity column clean-up and postcolumn photochemical derivatization.

    PubMed

    Wen, Jing; Kong, Weijun; Wang, Jian; Yang, Meihua

    2013-12-01

    Ginger, a widely used spice and traditional Chinese medicine, is prone to be contaminated by mycotoxins. A simple, sensitive, and reproducible method based on immunoaffinity column clean-up coupled with HPLC and on-line postcolumn photochemical derivatization with fluorescence detection was developed for the simultaneous determination of aflatoxins (AFs) B1 , B2 , G1 , G2 , and ochratoxin A (OTA) in 25 batches of gingers and related products marketed in China for the first time. The samples were first extracted by ultrasonication with methanol/water (80:20, v/v) and then cleaned up with immunoaffinity columns for analysis. Under the optimized conditions, the LODs and LOQs for the five mycotoxins were 0.03-0.3 and 0.1-0.9 μg/kg, respectively. The average recoveries ranged from 81.3-100.8% for AFs and from 88.6-99.5% for OTA at three spiking levels. Good linearity was observed for the analytes with correlation coefficients all >0.9995. All moldy gingers were contaminated with at least one kind of the five investigated mycotoxins, while none of them were found in normal gingers. Ginger powder samples were contaminated slightly with the contamination levels below the LOQs, while ginger tea bags were mainly contaminated by OTA at 1.05-1.19 μg/kg and ginger black tea bags were mainly contaminated by AFs at 3.37-5.76 μg/kg. All the contamination levels were below the legally allowable limits.

  12. Cleaning up the biogeography of Labroides dimidiatus using phylogenetics and morphometrics

    NASA Astrophysics Data System (ADS)

    Sims, C. A.; Riginos, C.; Blomberg, S. P.; Huelsken, T.; Drew, J.; Grutter, A. S.

    2014-03-01

    Cleaner fishes are some of the most conspicuous organisms on coral reefs due to their behaviour and prominent body pattern, consisting of a lateral stripe and blue/yellow colouration. All obligate cleaner fishes share this body stripe pattern, which is an important signal for attracting client fishes. However, variability in the cleaning signal of the cleaner fish Labroides dimidiatus has been documented across its range. Here, we investigate the geographic distribution of cleaner signal polymorphisms in L. dimidiatus and contrast this to phylogeographic variation in mitochondrial (mt) DNA. We used samples from 12 sites for genetic analyses, encompassing much of L. dimidiatus' range from the Red Sea to Fiji. We obtained morphometric measures of the cleaner signal body stripe width from individuals among six of the sites and qualitatively grouped tail stripe shape. mtDNA control region sequences were used for phylogenetic and population genetic analyses. We found that body stripe width was significantly correlated with tail stripe shape and geographical location, with Indian Ocean populations differing in morphology from western Pacific populations. L. dimidiatus haplotypes formed two reciprocally monophyletic clades, although in contrast to morphology, Japanese cleaner fish fell within the same clade as Indian Ocean cleaner fish and both clade types were sympatric in Papua New Guinea. An additional novel finding of our research was that the inclusion of two closely related cleaner fish species, Labroides pectoralis and Labroides bicolor, in the phylogenetic analysis rendered L. dimidiatus polyphyletic. Overall, the findings suggest the diversity within L. dimidiatus is underestimated.

  13. Determination of endocrine disrupting compounds in fish liver, brain, and muscle using focused ultrasound solid-liquid extraction and dispersive solid phase extraction as clean-up strategy.

    PubMed

    Ros, Oihana; Vallejo, Asier; Olivares, Maitane; Etxebarria, Nestor; Prieto, Ailette

    2016-08-01

    This study describes a new method for the simultaneous extraction of several endocrine disrupting compounds, including alkylphenols (APs), estrogen, bisphenol-A (BPA) and one phthalate metabolite (mono-2-ethylhexyl ester, MEHP) in fish liver, brain, and muscle. Parameters affecting the extraction (extraction solvent and temperature) and the clean-up (dispersive phase nature and amount) steps were evaluated. The extraction was performed by means of focused ultrasound solid-liquid extraction (FUSLE) using 10 mL of n-hexane:acetone (50:50, v/v) for 5 min at ~0 °C, and the clean-up was done by means of dispersive solid phase extraction (dSPE) using 100 mg of ENVI-CARB and 100 mg of MgSO4 for the cleaning of brain and muscle extracts together with 100 mg of PSA in the case of liver extracts. Good apparent recoveries were obtained in the case of liver (62-132 %), brain (66-120 %), and muscle (74-129 %), relative standard deviation (RSD%) was always below 26 %, and the method detection limits (MDLs) were at low ng/g level. The developed method was applied to fish captured in Urdaibai estuary (Bay of Biscay) in December 2015, and the concentrations obtained were in the range MDL-1115 ng/g in brain, MDL-962 ng/g in muscle, and MDL-672 ng/g in liver. In general, the highest concentrations were measured in liver, followed by brain and muscle. In addition, diethylstilbestrol was only detected in fish brain. Graphical Abstract MS method scheme for the/MS method scheme for the determination of EDCs in fish liver, brain and muscle.

  14. Determination of endocrine disrupting compounds in fish liver, brain, and muscle using focused ultrasound solid-liquid extraction and dispersive solid phase extraction as clean-up strategy.

    PubMed

    Ros, Oihana; Vallejo, Asier; Olivares, Maitane; Etxebarria, Nestor; Prieto, Ailette

    2016-08-01

    This study describes a new method for the simultaneous extraction of several endocrine disrupting compounds, including alkylphenols (APs), estrogen, bisphenol-A (BPA) and one phthalate metabolite (mono-2-ethylhexyl ester, MEHP) in fish liver, brain, and muscle. Parameters affecting the extraction (extraction solvent and temperature) and the clean-up (dispersive phase nature and amount) steps were evaluated. The extraction was performed by means of focused ultrasound solid-liquid extraction (FUSLE) using 10 mL of n-hexane:acetone (50:50, v/v) for 5 min at ~0 °C, and the clean-up was done by means of dispersive solid phase extraction (dSPE) using 100 mg of ENVI-CARB and 100 mg of MgSO4 for the cleaning of brain and muscle extracts together with 100 mg of PSA in the case of liver extracts. Good apparent recoveries were obtained in the case of liver (62-132 %), brain (66-120 %), and muscle (74-129 %), relative standard deviation (RSD%) was always below 26 %, and the method detection limits (MDLs) were at low ng/g level. The developed method was applied to fish captured in Urdaibai estuary (Bay of Biscay) in December 2015, and the concentrations obtained were in the range MDL-1115 ng/g in brain, MDL-962 ng/g in muscle, and MDL-672 ng/g in liver. In general, the highest concentrations were measured in liver, followed by brain and muscle. In addition, diethylstilbestrol was only detected in fish brain. Graphical Abstract MS method scheme for the/MS method scheme for the determination of EDCs in fish liver, brain and muscle. PMID:27342793

  15. Enrichment of perfluorinated alkyl substances on polyethersulfone using 1-methylpyperidine as ion-pair reagent for the clean-up of carrot and amended soil extracts.

    PubMed

    Bizkarguenaga, Ekhiñe; Zabaleta, Itsaso; Iparraguirre, Arantza; Aguirre, Josu; Fernández, Luis Ángel; Berger, Urs; Prieto, Ailette; Zuloaga, Olatz

    2015-10-01

    The development of a simple, cheap and environment friendly analytical method for the simultaneous determination of different perfluoroalkyl substances (PFASs) including seven perfluoroalkyl carboxylic acids, three perfluoroalkane sulfonic acids and perfluorooctanesulfonamide in carrot and amended soil was carried out in the present work. The method was based on focused ultrasound solid-liquid extraction followed by extract clean-up through enrichment of the target compounds on a polymeric material using an ion-pair reagent and detection by liquid chromatography-tandem mass spectrometry. The following variables affecting the clean-up step were evaluated: the nature of the polymeric material (polyethersulfone, PES, versus silicone rod), the amount of the polymeric material (from 1 to 9 mg), the ion-pair reagent (1-methylpyperidine, 1-MP, versus tetrabutylammonium salts), the concentration of the ion-pair reagent (from 5 to 50 mM) and the extraction time (from 15 min to 24 h). Optimum clean-up conditions were obtained using preconcentration on 9 mg of PES polymeric material combined with 5 mM 1-MP as ion-pair reagent for 3h. The method was validated in terms of apparent recoveries in the range of 77-140% and 95-137% at the low concentration (50 ng g(-1)) and in the range of 70-136% and 79-132% at the high concentration (290 ng g(-1)) for amended soil and carrot, respectively, after correction with the corresponding labeled standards. Precision, as relative standard deviation, was within 2-23%, while method detection limits were 0.31-2.85 ng g(-1) for amended soil and 0.11-1.83 ng g(-1) for carrot. In the absence of a certified reference material for the target analytes in the matrices studied, inter-method comparison was carried out and the same samples were processed using two independent clean-up procedures, the one developed in the present work and a classical based on solid-phase extraction. Statistically comparable results were obtained according to the one

  16. Enrichment of perfluorinated alkyl substances on polyethersulfone using 1-methylpyperidine as ion-pair reagent for the clean-up of carrot and amended soil extracts.

    PubMed

    Bizkarguenaga, Ekhiñe; Zabaleta, Itsaso; Iparraguirre, Arantza; Aguirre, Josu; Fernández, Luis Ángel; Berger, Urs; Prieto, Ailette; Zuloaga, Olatz

    2015-10-01

    The development of a simple, cheap and environment friendly analytical method for the simultaneous determination of different perfluoroalkyl substances (PFASs) including seven perfluoroalkyl carboxylic acids, three perfluoroalkane sulfonic acids and perfluorooctanesulfonamide in carrot and amended soil was carried out in the present work. The method was based on focused ultrasound solid-liquid extraction followed by extract clean-up through enrichment of the target compounds on a polymeric material using an ion-pair reagent and detection by liquid chromatography-tandem mass spectrometry. The following variables affecting the clean-up step were evaluated: the nature of the polymeric material (polyethersulfone, PES, versus silicone rod), the amount of the polymeric material (from 1 to 9 mg), the ion-pair reagent (1-methylpyperidine, 1-MP, versus tetrabutylammonium salts), the concentration of the ion-pair reagent (from 5 to 50 mM) and the extraction time (from 15 min to 24 h). Optimum clean-up conditions were obtained using preconcentration on 9 mg of PES polymeric material combined with 5 mM 1-MP as ion-pair reagent for 3h. The method was validated in terms of apparent recoveries in the range of 77-140% and 95-137% at the low concentration (50 ng g(-1)) and in the range of 70-136% and 79-132% at the high concentration (290 ng g(-1)) for amended soil and carrot, respectively, after correction with the corresponding labeled standards. Precision, as relative standard deviation, was within 2-23%, while method detection limits were 0.31-2.85 ng g(-1) for amended soil and 0.11-1.83 ng g(-1) for carrot. In the absence of a certified reference material for the target analytes in the matrices studied, inter-method comparison was carried out and the same samples were processed using two independent clean-up procedures, the one developed in the present work and a classical based on solid-phase extraction. Statistically comparable results were obtained according to the one

  17. The use of immunoaffinity columns connected in tandem for selective and cost-effective mycotoxin clean-up prior to multi-mycotoxin liquid chromatographic-tandem mass spectrometric analysis in food matrices.

    PubMed

    Wilcox, Joyce; Donnelly, Carol; Leeman, David; Marley, Elaine

    2015-06-26

    This paper describes the use of two immunoaffinity columns (IACs) coupled in tandem, providing selective clean-up, based on targeted mycotoxins known to co-occur in specific matrices. An IAC for aflatoxins+ochratoxin A+fumonisins (AOF) was combined with an IAC for deoxynivalenol+zearalenone+T-2/HT-2 toxins (DZT); an IAC for ochratoxin A (O) was combined with a DZT column; and an aflatoxin+ochratoxin (AO) column was combined with a DZT column. By combining pairs of columns it was demonstrated that specific clean-up can be achieved as required for different matrices. Samples of rye flour, maize, breakfast cereal and wholemeal bread were analysed for mycotoxins regulated in the EU, by spiking at levels close to EU limits for adult and infant foods. After IAC clean-up extracts were analysed by LC-MS/MS with quantification using multiple reaction monitoring. Recoveries were found to be in range from 60 to 108%, RSDs below 10% depending on the matrix and mycotoxin combination and LOQs ranged from 0.1n g/g for aflatoxin B1 to 13.0 ng/g for deoxynivalenol. Surplus cereal proficiency test materials (FAPAS(®)) were also analysed with found levels of mycotoxins falling within the satisfactory range of concentrations (Z score ≤ ± 2), demonstrating the accuracy of the proposed multi-mycotoxin IAC methods. PMID:25990350

  18. Application of ion-exchange cartridge clean-up in food analysis. V. Simultaneous determination of sulphonamide antibacterials in animal liver and kidney using high-performance liquid chromatography with ultraviolet and mass spectrometric detection.

    PubMed

    Ito, Y; Oka, H; Ikai, Y; Matsumoto, H; Miyazaki, Y; Nagase, H

    2000-11-10

    A simple, rapid, and reliable method for the determination of residual sulphonamide antibacterials (SAs) (sulfadiazine, sulfamerazine, sulfadimidine, sulfamethoxypiridazine, sulfisozole, sulfamonomethoxine, sulfamethoxazole, sulfisoxazole, sulfadimethoxine, and sulfaquinoxaline) in animal liver and kidney was developed using a combination of clean-up on a Bond Elut PSA cartridge and HPLC with UV detection. The SAs were extracted with ethyl acetate and then dissolved in 5 ml of 50 v/v% ethyl acetate-n-hexane after being evaporated to dryness. For clean-up of the crude sample, the resuspended extract was applied to a Bond Elut PAS (primary/secondary amine cartridge), and then SAs were eluted from the cartridge using 5 ml of 20 v/v% acetonitrile-0.05 M ammonium formate before being analysed by HPLC. Recoveries of the SAs at the levels of 0.5 and 0.1 microg/g were 70.8-98.2%, the rerative standard deviation were less than 7.0%, and the detection limits were 0.03 microg/g. The present analysis method of SAs in animal kidney and liver using HPLC with a clean-up procedure was demonstrated to be highly applicable to the direct LC-MS-MS analysis without any modification. PMID:11185627

  19. SIMPLE SAMPLE CLEAN UP PROCEDURE AND HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC METHOD FOR THE ANALYSIS OF CYANURIC ACID IN HUMAN URINE

    EPA Science Inventory

    Cyanuric acide (CA) is widely used as a chlorine stabilizer in outdoor pools. No simple method exists for CA measurement in the urine of exposed swimmers. The high hydrophilicity of CA makes usage of solid phase sorbents to extract it from urine nearly impossible because of samp...

  20. Absorbent Pads for Containment, neutralization, and clean-up of environmental spills containing chemically-reactive agents

    NASA Technical Reports Server (NTRS)

    Davis, Dennis D. (Inventor)

    1996-01-01

    A pad for cleaning up liquid spills is described which contains a porous surface covering, and an absorbent interior containing chemically reactive reagents for neutralizing noxious chemicals within the spilled liquid. The porous surface and the absorbent component would normally consist of chemically resistant materials allowing tentative spill to pass. The absorbent interior which contains the neutralizing reagents can but is not required to be chemically resilient and conducts the liquid chemically reactive reagents where the dangerous and undesirable chemicals within the chemical spill are then neutralized as well as removed from the premises.

  1. Absorbent pads for Containment, Neutralization, and Clean-Up of Environmental Spills Containing Chemically-Reactive Agents

    NASA Technical Reports Server (NTRS)

    Davis, Dennis D. (Inventor)

    1997-01-01

    A pad for cleaning up liquid spills is described which contains a porous surface covering, and an absorbent interior containing chemically reactive reagents for neutralizing noxious chemicals within the spilled liquid. The porous surface and the absorbent component would normally consist of chemically resistant materials allowing tentative spill to pass. The absorbent interior which contains the neutralizing reagents can but is not required to be chemically resilient and conducts the liquid chemical spill towards the absorbent interior containing the chemically reactive reagents where the dangerous and undesirable chemicals within the chemical spill are then neutralized as well as removed from the premises.

  2. Method of and apparatus for preheating pressurized fluidized bed combustor and clean-up subsystem of a gas turbine power plant

    DOEpatents

    Cole, Rossa W.; Zoll, August H.

    1982-01-01

    In a gas turbine power plant having a pressurized fluidized bed combustor, gas turbine-air compressor subsystem and a gas clean-up subsystem interconnected for fluid flow therethrough, a pipe communicating the outlet of the compressor of the gas turbine-air compressor subsystem with the interior of the pressurized fluidized bed combustor and the gas clean-up subsystem to provide for flow of compressed air, heated by the heat of compression, therethrough. The pressurized fluidized bed combustor and gas clean-up subsystem are vented to atmosphere so that the heated compressed air flows therethrough and loses heat to the interior of those components before passing to the atmosphere.

  3. 49 CFR 199.111 - Retention of samples and additional testing.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Retention of samples and additional testing. 199... SAFETY DRUG AND ALCOHOL TESTING Drug Testing § 199.111 Retention of samples and additional testing. (a... period, the employee or the employee's representative, the operator, the Administrator, or, if...

  4. Molecularly imprinted polymer-based solid phase clean-up for analysis of ochratoxin A in beer, red wine, and grape juice.

    PubMed

    Cao, Jiliang; Kong, Weijun; Zhou, Shujun; Yin, Lihui; Wan, Li; Yang, Meihua

    2013-04-01

    A simple, reliable, and low-cost method based on molecularly imprinted polymer as a selective sorbent of SPE was proposed for the determination of ochratoxin A (OTA) in beer, red wine, and grape juice by HPLC coupled with fluorescence detection (HPLC-FLD). Samples were diluted with water and cleaned up with an AFFINIMIP® SPE OTA column. After washing and eluting, the analyte was analyzed by HPLC-FLD. Under the optimized conditions, LOD and LOQ for OTA were 0.025 and 0.08 ng/mL, respectively. The recoveries of OTA from beer, red wine, and grape spiked at 0.1, 2, and 5 ng/mL ranged from 91.6 to 101.7%. Furthermore, after a simple regenerated procedure, the molecularly imprinted polymer based SPE column could be reused at least 14 times to achieve more than 80% recoveries of OTA in real samples. The developed method was applied to the detection of 30 beer, red wine, and grape juice samples and only four samples were contaminated by OTA with levels below the legal limits.

  5. [The retrospective cytogenetic dosimetry using the results of conventional chromosomal analysis in Chernobyl clean-up workers].

    PubMed

    Maznik, N A; Vinnikov, V A

    2005-01-01

    The paper presents the results of the cohortal biodosimetry carried out in 435 Chernobyl clean-up workers, who were surveyed with the conventional cytogenetic technique in terms from several days to 10 years after the end of their duties in the Chernobyl accident exclusive zone. An empirical model of the aberrant cell dynamics was utilized for the calculation of mean initial yields of dicentrics and centric rings in groups with different terms and duration of staying in the Chernobyl zone. Corresponding protracted irradiation doses estimated from aberration levels ranged from 79 to 670 mGy. The probabilistic distribution of the radiation doses was constructed by the applying the Bayesian analysis to initial individual chromosome exchange yields extrapolated to the exposure termination moment. This distribution was characterized by the mean dose about 460 mGy and maximum of probability density in the interval of 50-300 mGy. For the late somatic risk assessment in clean-up workers the probabilistic distribution of equivalentally-acute radiation doses was proposed; that had the mean value about 270 mGy, modal classes of 250-350 mGy and 99.8% of the probability density concentrated within the dose range from 0 to 1000 mGy. PMID:16454338

  6. Development of a bi-functional silica monolith for electro-osmotic pumping and DNA clean-up/extraction using gel-supported reagents in a microfluidic device.

    PubMed

    Oakley, Jennifer A; Shaw, Kirsty J; Docker, Peter T; Dyer, Charlotte E; Greenman, John; Greenway, Gillian M; Haswell, Stephen J

    2009-06-01

    A silica monolith used to support both electro-osmotic pumping (EOP) and the extraction/elution of DNA coupled with gel-supported reagents is described. The benefits of the combined EOP extraction/elution system were illustrated by combining DNA extraction and gene amplification using the polymerase chain reaction (PCR) process. All the reagents necessary for both processes were supported within pre-loaded gels that allow the reagents to be stored at 4 degrees C for up to four weeks in the microfluidic device. When carrying out an analysis the crude sample only needed to be hydrodynamically introduced into the device which was connected to an external computer controlled power supply via platinum wire electrodes. DNA was extracted with 65% efficiency after loading lysed cells onto a silica monolith. Ethanol contained within an agarose gel matrix was then used to wash unwanted debris away from the sample by EOP (100 V cm(-1) for 5 min). The retained DNA was subsequently eluted from the monolith by water contained in a second agarose gel, again by EOP using an electric field of 100 V cm(-1) for 5 min, and transferred into the PCR reagent containing gel. The eluted DNA in solution was successfully amplified by PCR, confirming that the concept of a complete self-contained microfluidic device could be realised for DNA sample clean up and amplification, using a simple pumping and on-chip reagent storage methodology.

  7. Results of the clean-up operation to reduce pollution on flooded agricultural fields after the red mud spill in Hungary.

    PubMed

    Uzinger, Nikolett; Anton, Áron Dániel; Ötvös, Károly; Tamás, Péter; Anton, Attila

    2015-07-01

    In Hungary, the dam of a red mud reservoir breached shortly after noon on October 4, 2010. Approximately 0.7-1 million m(3) highly alkaline red mud with very low dry matter content flowed into the Torna Creek and the surrounding area, covering 1017 ha of agricultural land. Results of the risk assessment of the accident indicated that the red mud should be removed from the surface of fields where it formed a continuous layer of more than 5 cm. After the removal, samples were taken manually from depths of 0.0-0.2 m and 0.2-0.4 m in a sampling grid and background samples unaffected by red mud from the depth of 0.0-0.3 m. Total element contents (Ag, As, Ba, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Sn, Zn, and Na) and pH values were measured, and the results were analysed using correlation analysis and the Kruskal-Wallis probe. Dependence of the measured variables from elevation above sea level was studied using a 10 m by 10 m digital elevation model. Only ∼6.5% of the flooded area was temporarily designated as unsuitable for the production of food and fodder crops. In summary, the clean-up operation can be said to have been a success.

  8. In-cell clean-up pressurized liquid extraction and gas chromatography-tandem mass spectrometry determination of hydrophobic persistent and emerging organic pollutants in coastal sediments.

    PubMed

    Pintado-Herrera, Marina G; González-Mazo, Eduardo; Lara-Martín, Pablo A

    2016-01-15

    The main goal of this work was to develop, optimize and validate a multi-residue method for the simultaneous determination of 97 contaminants, including fragrances, UV filters, repellents, endocrine disruptors, biocides, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organophosphorus flame retardants, and several types of pesticides in marine sediment samples. Extraction and cleanup were integrated into the same step using pressurized liquid extraction (PLE) with in-cell clean-up (1g of alumina). The extraction was performed using dichloromethane at 100 °C, 1500 psi and 3 extraction cycles (5 min per cycle). Extracts were derivatized with N-(tert-butyldimethylsilyl)-N-methyltrifluoroacetamide (MTBSTFA) to improve the signal and sensitivity of some target compounds (i.e., triclosan, 2-hydroxybenzophenone). Separation, identification and quantification of analytes were carried out by gas chromatography (GC) coupled to tandem mass spectrometry. Under optimal conditions, the optimized protocol showed good recovery percentages (70-100%), linearity (>0.99) and limits of detection below 1 ng g(-1) for all compounds. Finally, the method was applied to the analysis of sediment samples from different coastal areas from Andalusia (Spain), where occurrence and distribution of emerging contaminants in sediments is very scarce. Twenty five compounds out of 98 were detected in all samples, with the endocrine disruptor nonylphenol and the fragrance galaxolide showing the highest concentrations, up to 377.6 ng g(-1) and 237.4 ng g(-1), respectively.

  9. Results of the clean-up operation to reduce pollution on flooded agricultural fields after the red mud spill in Hungary.

    PubMed

    Uzinger, Nikolett; Anton, Áron Dániel; Ötvös, Károly; Tamás, Péter; Anton, Attila

    2015-07-01

    In Hungary, the dam of a red mud reservoir breached shortly after noon on October 4, 2010. Approximately 0.7-1 million m(3) highly alkaline red mud with very low dry matter content flowed into the Torna Creek and the surrounding area, covering 1017 ha of agricultural land. Results of the risk assessment of the accident indicated that the red mud should be removed from the surface of fields where it formed a continuous layer of more than 5 cm. After the removal, samples were taken manually from depths of 0.0-0.2 m and 0.2-0.4 m in a sampling grid and background samples unaffected by red mud from the depth of 0.0-0.3 m. Total element contents (Ag, As, Ba, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Sn, Zn, and Na) and pH values were measured, and the results were analysed using correlation analysis and the Kruskal-Wallis probe. Dependence of the measured variables from elevation above sea level was studied using a 10 m by 10 m digital elevation model. Only ∼6.5% of the flooded area was temporarily designated as unsuitable for the production of food and fodder crops. In summary, the clean-up operation can be said to have been a success. PMID:25647492

  10. NucleoSpin(®) XS Columns for DNA Concentration and Clean-Up.

    PubMed

    Hudlow, William R

    2016-01-01

    The phenol-chloroform (organic) extraction method continues to be a preferred method for extraction of DNA from forensic evidence samples that may contain low quantities of DNA and polymerase chain reaction (PCR) inhibitors. The aqueous extracts from the organic extraction of DNA require subsequent concentration and cleanup, which has traditionally been performed with microdialysis filter units, including the Centricon(®) and Microcon(®) centrifugal filter devices. Here, we describe the use of the NucleoSpin(®) XS silica columns as an alternative for the concentration and purification of the aqueous extracts from the organic extraction and for the removal of PCR inhibitors from existing DNA extracts. PMID:27259735

  11. NucleoSpin(®) XS Columns for DNA Concentration and Clean-Up.

    PubMed

    Hudlow, William R

    2016-01-01

    The phenol-chloroform (organic) extraction method continues to be a preferred method for extraction of DNA from forensic evidence samples that may contain low quantities of DNA and polymerase chain reaction (PCR) inhibitors. The aqueous extracts from the organic extraction of DNA require subsequent concentration and cleanup, which has traditionally been performed with microdialysis filter units, including the Centricon(®) and Microcon(®) centrifugal filter devices. Here, we describe the use of the NucleoSpin(®) XS silica columns as an alternative for the concentration and purification of the aqueous extracts from the organic extraction and for the removal of PCR inhibitors from existing DNA extracts.

  12. Phytoextraction for clean-up of low-level uranium contaminated soil evaluated.

    PubMed

    Vandenhove, H; Van Hees, M

    2004-01-01

    Spills in the nuclear fuel cycle have led to soil contamination with uranium. In case of small contamination just above release levels, low-cost yet sufficiently efficient remedial measures are recommended. This study was executed to test if low-level U contaminated sandy soil from a nuclear fuel processing site could be phytoextracted in order to attain the required release limits. Two soils were tested: a control soil (317 Bq 238U kg(-1)) and the same soil washed with bicarbonate (69 Bq 238U kg(-1)). Ryegrass (Lolium perenne cv. Melvina) and Indian mustard (Brassica juncea cv. Vitasso) were used as test plants. The annual removal of soil activity by the biomass was less than 0.1%. The addition of citric acid (25 mmol kg(-1)) 1 week before the harvest increased U uptake up to 500-fold. With a ryegrass and mustard yield of 15,000 and 10,000 kg ha(-1), respectively, up to 3.5% and 4.6% of the soil activity could be removed annually by the biomass. With a desired activity reduction level of 1.5 and 5 for the bicarbonate-washed and control soil, respectively, it would take 10-50 years to attain the release limit. However, citric acid addition resulted in a decreased dry weight production. PMID:15162854

  13. Microwave-assisted extraction at atmospheric pressure coupled to different clean-up methods for the determination of organophosphorus pesticides in olive and avocado oil.

    PubMed

    Fuentes, Edwar; Báez, María E; Díaz, Juan

    2009-12-18

    An effective extraction method was devised for the determination of organophosphorus pesticides (OPPs) in olive and avocado oil samples, using atmospheric pressure microwave-assisted liquid-liquid extraction (APMAE) and solid-phase extraction or low-temperature precipitation as clean-up step. A simple glass system equipped with an air-cooled condenser was designed as an extraction vessel. The pesticides were partitioned between acetonitrile and oil solution in hexane. Analytical determinations were carried out by gas chromatography-flame photometric detection and gas chromatography-tandem mass spectrometry, using a triple quadrupole mass analyzer, for confirmation purposes. Several factors influencing the extraction efficiency were investigated and optimized through fractional factorial design and Doehlert design. Under optimal conditions the recovery of pesticides from oil at 0.025 microg g(-1) ranged from 71% to 103%, except for fenthion in avocado oil, with RSDs < or = 13% (n=5). The LOQ for the entire method ranged from 0.004 to 0.015 microg g(-1). Finally, the proposed method was successfully applied to the extraction and determination of the selected pesticides in 20 commercially packed extra virgin olive oils and four commercially packed avocado oils produced in Chile. Detectable residues of different OPPs were observed in 85% of samples. PMID:19926091

  14. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  15. Iron nanoparticles for environmental clean-up: recent developments and future outlook.

    PubMed

    Yan, Weile; Lien, Hsing-Lung; Koel, Bruce E; Zhang, Wei-xian

    2013-01-01

    Nanoscale zero-valent iron (nZVI) is one of the most extensively applied nanomaterials for groundwater and hazardous waste treatment. In the past fifteen years, progress made in several key areas has deepened our understanding of the merits and uncertainties of nZVI-based remediation applications. These areas include the materials chemistry of nZVI in its simple and modified forms, the nZVI reactivity with a wide spectrum of contaminants in addition to the well-documented chlorinated solvents, methods to enhance the colloidal stability and transport properties of nZVI in porous media, and the effects of nZVI amendment on the biogeochemical environment. This review aims to provide an up-to-date account of advancement in these areas as well as insights gained through field experience.

  16. Immunoaffinity column clean-up prior to thin-layer chromatography for the determination of aflatoxins in various food matrices.

    PubMed

    Stroka, J; Van Otterdijk, R; Anklam, E

    2000-12-29

    A one-dimensional TLC method to determine aflatoxins (B1, B2, G1, G2) in various food matrices was elaborated which abstains fully on the use of chlorinated solvents. It implements an immunoaffinity clean-up step after extraction with methanol. The aflatoxins were quantified by densitometry. The method has shown to be rapid and efficient. In-house performance characteristics were established. The limit of quantification was found to be significantly lower than current regulatory limits for aflatoxin control outside and within the European Community. The obtained recovery and precision data gave a strong indication, that the method is likely to give satisfactory performance if tested in a future collaborative trial. PMID:11204238

  17. [CHANGES OF GLOBAL AND LOCAL MYOCARDIAL CONTRACTILITY OF CHERNOBYL ACCIDENT CLEAN-UP WORKERS WITH STABLE ANGINA].

    PubMed

    Nastina, O

    2014-01-01

    Changes of global and local myocardial contractility of Chernobyl accident clean-up workers (ChA CW) with stable angina were investigated. There were discovered that regular long-term treatment of ChA CW with stable angina using of antiischemic and metabolic drugs promoted to stabilization of global and local myocardial contractility indexes. Ejection fraction, degree of contraction of front-rear systolic left ventricle size, systolic thickness of interventricular septum sufficiently increased. Step-by-step worsening of global and local myocardial contractility indexes in cases of non-regular treatment was taken place. Sufficient differences between indexes of ejection fraction, left ventricle end-diastolic volume, systolic thickness and excursion of interventricular septum in stable angina patients of general population and ChA CW were discovered. Results of global and local myocardial contractility monitoring in ChA CW with stable angina substantiate the advisability of long-term supporting treatment using evidence-based drugs.

  18. [Comparative analysis of the combined treatment efficacy of the Chernobyl accident clean-up workers with essential hypertension].

    PubMed

    Habulavichene, Zh M

    2012-12-01

    It was shown the results of comparative evaluation of combined treatment in 111 clean-up workers of Chernobyl accident with essential hypertension (EH). This treatment consist of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers in combination with calcium channel blockers and diuretics. The follow-up period lasted 12 months. It was found that combined therapy provides comparable and reliable blood pressure (BP) control during 24-hour, significant reduction of average daily BP, daytime and nighttime BP, an index of time of the BP, BP variability. Despite on achieved target blood pressure level, 4 weeks treatment is not enough for regression of left ventricular hypertrophy (LVH). Significant regress of LVH was found if treatment lasted during a year under the condition that BP remained at the target level. It was revealed the advantage of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers intake combined with a diuretic on regress of left ventricular hypertrophy and dysfunction.

  19. Is the cutting of oil contaminated marshes an efficient clean-up technique in a subtropical estuary?

    PubMed

    Wolinski, André L T O; Lana, Paulo C; Sandrini-Neto, Leonardo

    2011-06-01

    Cutting and removal of oil-impacted marsh plants are still used worldwide as a clean-up and recovery technique. To experimentally test the efficacy of cutting and removing marsh plants under subtropical conditions, we simulated an oil spill (Bunker MF-180) in Spartina alterniflora marshes and compared the responses of plant height, biomass, density of culms and number of flowering plants in high and low energy areas in Paranaguá Bay (S Brazil) for about 9 months. Cutting and removal were inefficient in promoting or accelerating the recovery of the impacted areas. Cut or uncut impacted marshes fully recovered within 6 months, both in low and high energy areas. Plant cutting should be practiced only when there is an effective risk of contamination of groundwater near urban areas, when obvious aesthetical issues are involved in areas of touristic interest or when there are real short-term conservation risks to threatened species.

  20. Clean-up progress at the SNL/NM Classified Waste Landfill

    SciTech Connect

    Slavin, P.J.; Galloway, R.B.

    1999-11-30

    The Sandia National Laboratories/New Mexico (SNL/NM)Environmental Restoration Project is currently excavating the Classified Waste Landfill in Technical Area II, a disposal area for weapon components for approximately 40 years until it closed in 1987. Many different types of classified parts were disposed in unlined trenches and pits throughout the course of the landfill's history. A percentage of the parts contain explosives and/or radioactive components or contamination. The excavation has progressed backward chronologically from the last trenches filled through to the earlier pits. Excavation commenced in March 1998, and approximately 75 percent of the site (as defined by geophysical anomalies) has been completed as of November 1999. The material excavated consists primarily of classified weapon assemblies and related components, so disposition must include demilitarization and sanitization. This has resulted in substantial waste minimization and cost avoidance for the project as upwards of 90 percent of the classified materials are being demilitarized and recycled. The project is using field screening and lab analysis in conjunction with preliminary and in-process risk assessments to characterize soil and make waste determinations in a timely a fashion as possible. Challenges in waste management have prompted the adoption of innovative solutions. The hand-picked crew (both management and field staff) and the ability to quickly adapt to changing conditions has ensured the success of the project. The current schedule is to complete excavation in July 2000, with follow-on verification sampling, demilitarization, and waste management activities following.

  1. 49 CFR 199.111 - Retention of samples and additional testing.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY DRUG AND ALCOHOL TESTING Drug Testing § 199.111 Retention of samples and additional testing. (a) Samples that yield positive results on confirmation must be retained by the laboratory in properly...

  2. 40 CFR 80.8 - Sampling methods for gasoline, diesel fuel, fuel additives, and renewable fuels.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. To enforce any edition other than... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Sampling methods for gasoline, diesel... Provisions § 80.8 Sampling methods for gasoline, diesel fuel, fuel additives, and renewable fuels....

  3. Chemical Pollution and Evolution of Massive Starbursts: Cleaning up the Environment in Star-Forming Galaxies

    NASA Astrophysics Data System (ADS)

    Kobulnicky, C.

    1996-12-01

    I present the results of a research program seeking to characterize the impact of massive star-clusters on the chemical and dynamical evolution of metal-poor, irregular and blue compact galaxies. The evolution of high mass stars is thought to contribute the bulk of heavy element enrichment in the interstellar medium, especially alpha -process elements like O, Si, etc. Yet, in actively star-forming galaxies, localized chemical inhomogeneities are seldom observed. Spatially-resolved optical and ultraviolet spectroscopy from the Hubble Space Telescope and ground-based observatories is used to search for chemical enrichment in the vicinity of young star clusters in nearby galaxies. VLA aperture synthesis maps are used to examine the neutral hydrogen content, dynamics, and local environment of the sample galaxies. Despite the spread in evolutionary state of the starbursts determined by the EW of Balmer emission lines and the radio continuum spectral index, few instances of localized enrichment are found. In light of these data, the ``instantaneous enrichment'' scenario for extragalactic HII regions appears less probable than one which operates on long timescales and global spatial scales. The results are consistent with the idea that starburst driven winds expel freshly synthesized metals in a hot 10(6) K phase into the halos of galaxies where they cool, condense into globules, and mix homogeneously with the rest of the galaxy on long (dynamical) timescales. The C/O and N/O ratios of the galaxies are used as new tools for measuring the recent star formation history. Implications for chemical evolution of galaxies both locally and cosmologically are developed.

  4. SOx-NOx-Rox Box{trademark} flue gas clean-up demonstration. Final report

    SciTech Connect

    1995-09-01

    The SNRB{trademark} Flue Gas Cleanup Demonstration Project was cooperatively funded by the U.S. Department of Energy (DOE), the Ohio Coal Development Office (OCDO), B&W, the Electric Power Research Institute (EPRI), Ohio Edison, Norton Chemical Process Products Company and the 3M Company. The SNRB{trademark} technology evolved from the bench and laboratory pilot scale to be successfully demonstrated at the 5-MWe field scale. Development of the SNRB{trademark} process at B&W began with pilot testing of high-temperature dry sorbent injection for SO{sub 2} removal in the 1960`s. Integration of NO{sub x} reduction was evaluated in the 1970`s. Pilot work in the 1980`s focused on evaluation of various NO{sub x} reduction catalysts, SO{sub 2} sorbents and integration of the catalyst with the baghouse. This early development work led to the issuance of two US process patents to B&W - No. 4,309,386 and No. 4,793,981. An additional patent application for improvements to the process is pending. The OCDO was instrumental in working with B&W to develop the process to the point where a larger scale demonstration of the technology was feasible. This report represents the completion of Milestone M14 as specified in the Work Plan. B&W tested the SNRB{trademark} pollution control system at a 5-MWe demonstration facility at Ohio Edison`s R. E. Burger Plant located near Shadyside, Ohio. The design and operation were influenced by the results from laboratory pilot testing at B&W`s Alliance Research Center. The intent was to demonstrate the commercial feasibility of the SNRB{trademark} process. The SNRB{trademark} facility treated a 30,000 ACFM flue gas slipstream from Boiler No. 8. Operation of the facility began in May 1992 and was completed in May 1993.

  5. Evaluation of the persistence of functional and biological respiratory health effects in clean-up workers 6 years after the prestige oil spill.

    PubMed

    Zock, Jan-Paul; Rodríguez-Trigo, Gema; Rodríguez-Rodríguez, Emma; Souto-Alonso, Ana; Espinosa, Ana; Pozo-Rodríguez, Francisco; Gómez, Federico P; Fuster, Carme; Castaño-Vinyals, Gemma; Antó, Josep Maria; Barberà, Joan Albert

    2014-01-01

    Fishermen who had participated in clean-up activities of the Prestige oil spill showed increased bronchial responsiveness and higher levels of respiratory biomarkers 2 years later. We aimed to evaluate the persistence of these functional and biological respiratory health effects 6 years after clean-up work. In 2008/2009 a follow-up study was done in 230 never-smoking fishermen who had been exposed to clean-up work in 2002/2003 and 87 non-exposed fishermen. Lung function and bronchial responsiveness testing and the determination of respiratory biomarkers in exhaled breath condensate were done identically as in the baseline survey in 2004/2005. Associations between participation in clean-up work and respiratory health parameters were assessed using linear and logistic regression analyses adjusting for sex and age. Information from 158 exposed (69%) and 57 non-exposed (66%) fishermen was obtained. Loss to follow-up in the non-exposed was characterised by less respiratory symptoms at baseline. During the 4-year follow-up period lung function, bronchial hyperresponsiveness and the levels of respiratory biomarkers of oxidative stress and growth factors had deteriorated notably more among non-exposed than among exposed. At follow-up, respiratory health indices were similar or better in clean-up workers than in non-exposed. No clear differences between highly exposed and moderately exposed clean-up workers were found. In conclusion, we could not detect long-term respiratory health effects in clean-up workers 6 years after the Prestige oil spill. Methodological issues that need to be considered in this type of studies include the choice of a non-exposed control group and limitation of follow-up to subgroups such as never smokers.

  6. THE ROLE OF LIQUID WASTE PRETREATMENT TECHNOLOGIES IN SOLVING THE DOE CLEAN-UP MISSION

    SciTech Connect

    Wilmarth, B; Sheryl Bush, S

    2008-10-31

    The objective of this report is to describe the pretreatment solutions that allow treatment to be tailored to specific wastes, processing ahead of the completion schedules for the main treatment facilities, and reduction of technical risks associated with future processing schedules. Wastes stored at Hanford and Savannah River offer challenging scientific and engineering tasks. At both sites, space limitations confound the ability to effectively retrieve and treat the wastes. Additionally, the radiation dose to the worker operating and maintaining the radiochemical plants has a large role in establishing the desired radioactivity removal. However, the regulatory requirements to treat supernatant and saltcake tank wastes differ at the two sites. Hanford must treat and remove radioactivity from the tanks based on the TriParty Agreement and Waste Incidental to Reprocessing (WIR) documentation. These authorizing documents do not specify treatment technologies; rather, they specify endstate conditions. Dissimilarly, Waste Determinations prepared at SRS in accordance with Section 3116 of the 2005 National Defense Authorization Act along with state operating permits establish the methodology and amounts of radioactivity that must be removed and may be disposed of in South Carolina. After removal of entrained solids and site-specific radionuclides, supernatant and saltcake wastes are considered to be low activity waste (LAW) and are immobilized in glass and disposed of at the Hanford Site Integrated Disposal Facility (IDF) or formulated into a grout for disposal at the Savannah River Site Saltstone Disposal Facility. Wastes stored at the Hanford Site or SRS comprise saltcake, supernate, and sludges. The supernatant and saltcake waste fractions contain primarily sodium salts, metals (e.g., Al, Cr), cesium-137 (Cs-137), technetium-99 (Tc-99) and entrained solids containing radionuclides such as strontium-90 (Sr-90) and transuranic elements. The sludges contain many of the

  7. Analysis of zinc in biological samples by flame atomic absorption spectrometry: use of addition calibration technique.

    PubMed

    Dutra, Rosilene L; Cantos, Geny A; Carasek, Eduardo

    2006-01-01

    The quantification of target analytes in complex matrices requires special calibration approaches to compensate for additional capacity or activity in the matrix samples. The standard addition is one of the most important calibration procedures for quantification of analytes in such matrices. However, this technique requires a great number of reagents and material, and it consumes a considerable amount of time throughout the analysis. In this work, a new calibration procedure to analyze biological samples is proposed. The proposed calibration, called the addition calibration technique, was used for the determination of zinc (Zn) in blood serum and erythrocyte samples. The results obtained were compared with those obtained using conventional calibration techniques (standard addition and standard calibration). The proposed addition calibration was validated by recovery tests using blood samples spiked with Zn. The range of recovery for blood serum and erythrocyte samples were 90-132% and 76-112%, respectively. Statistical studies among results obtained by the addition technique and conventional techniques, using a paired two-tailed Student's t-test and linear regression, demonstrated good agreement among them. PMID:16943611

  8. A method for determining fumonisin B1 in corn using immunoaffinity column clean-up and thin layer chromatography/densitometry.

    PubMed

    Preis, R A; Vargas, E A

    2000-06-01

    A method for determining fumonisin B1 (FB1) in corn was developed and the clean-up optimized in order to give an extract suitable for one-dimensional thin layer chromatographic (TLC) analysis. FB1 was extracted with a solution of methanol:water (80:20, v/v), purified through an immunoaffinity column and separated on a C18 reversed phase TLC plate. The FB1 was visualized with 0.1 mol/l sodium tetraborate, 0.40 mg/ml fluorescamine in acetonitrile and 0.01 mol/l boric acid:acetonitrile (2:3, v/v) for fluorescence detection, and quantified by densitometric analysis. Water, acetonitrile:water (1:1 v/v) and acetonitrile:water (4:1 v/v) were evaluated as TLC solvents for running both standards and samples together with derivatization procedures aimed at improving separation, resolution, sensitivity and linearity. The mean recovery for FB1 for spiked samples was found to be 85% and the linear equation of standard calibration curve by densitometric analysis gave an r2 value higher than 0.99. The maximum coefficient of variation for replicate analysis of spiked samples was 19%. The absolute amount of FB1 standard detectable on a TLC plate was 2 ng, giving a detection limit for the method of 0.1 mg/kg. The method has been shown to be robust in the application of FB1 monitoring in corn (214 samples) collected in different regions of the country. FB1 was detected in 99% of these samples in the range of 0.2 to 6 mg/kg. PMID:10932789

  9. A multi-residue method for the determination of 90 pesticides in matrices with a high water content by LC-MS/MS without clean-up.

    PubMed

    Madureira, Fernando Diniz; da Silva Oliveira, Fabiano Aurélio; de Souza, Wesley Robert; Pontelo, Ana Paula; de Oliveira, Mauro Lúcio Gonçalves; Silva, Gilsara

    2012-01-01

    A method using QuEChERS extraction and LC-MS/MS in electrospray positive ionisation mode was developed and validated for the analysis of 90 pesticides in a high water content matrix (tomato) in a single chromatographic run. To assess the intra-laboratory reproducibility of the method, validation was conducted on four different days by two different analysts. The validation data was treated using a spreadsheet developed in-house, which sets the most appropriate model for linear fit by determining whether the residuals of the calibration curves are homocedastic or heterocedastic. A statistical test for the significance of regression was also carried out. Calibration was always matrix-matched and the curves were obtained over the range 0.0075-0.10 or 0.020-0.125 mg kg(-1). Identification of analytes was based on retention times and MRM ratios. Recoveries were assessed at four different levels for each analyte and were between 73 and 106%, with relative standard deviations under reproducibility conditions of <20%. The measurement uncertainties of the method for each pesticide analysed were below 50%. Previous validation of the same method, applied to papaya samples and satisfactory results obtained in various proficiency tests with different high water content matrices, demonstrated the applicability of the method to these classes of commodities, without clean-up. The validated method will be applied routinely in the pesticide residues monitoring programme that constitutes the National Residue and Contaminant Control Plan of Brazil.

  10. Simultaneous pressurized liquid extraction and clean-up for the analysis of polybrominated biphenyls by gas chromatography-tandem mass spectrometry.

    PubMed

    Malavia, J; Santos, F J; Galceran, M T

    2011-05-30

    This paper describes a fast and simple pressurized liquid extraction (PLE) method combined with gas chromatography coupled to ion trap tandem mass spectrometry (GC-ITMS-MS) for the determination of polybrominated biphenyls (PBBs) in fish samples. The method is based on a simultaneous extraction/clean-up step to reduce analysis time and solvent consumption. The effect of several PLE operating conditions, such as solvent type, extraction temperature and time, number of cycles, and lipid retainer, was optimized to obtain maximum recovery of the analytes with the minimum presence of matrix-interfering compounds. The best conditions were obtained at 100°C with n-hexane using 15 g of silica modified with sulphuric acid (44%, w/w) as sorbent for lipid removal. Quality parameters of the GC-ITMS-MS method were established, achieving good linearity (r>0.998), between 1 and 500 ng ml(-1), and low instrumental limits of detection (0.14-0.76 pg injected). For the whole method, limits of detection ranging from 0.03 to 0.16 ng g(-1) wet weight and good precision (RSD<16%) were obtained. PMID:21530792

  11. [Analysis of aldicarb and its metabolites in ginger using ultra performance liquid chromatography-tandem mass spectrometry coupled with multiplug filtration clean up with multiwalled carbon nanotubes].

    PubMed

    Ma, Lili; Jia, Li; Zhou, Xinran; Liu, Yan; Fan, Xiaojing; Pan, Canping

    2014-06-01

    A simple and rapid pretreatment procedure was developed for the simultaneous determination of aldicarb and its metabolites, aldicarb sulfone and aldicarb sulfoxide in ginger. The samples were extracted with acetonitrile, and then cleaned up with multiplug filtration using multiwalled carbon nanotubes (MWCNTS). The eluate was dried with nitrogen gas at room temperature, and redissolved in an acetonitrile-water (5:95, v/v) mixture, then quantified by ultra performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) operated in positive multiple reaction monitoring (MRM) mode. A linear relationship was achieved in the range of 0.5 -200 microg/L for the peak areas to the mass concentrations of the target compounds with the linear correlation coefficients (r2) higher than 0.99. The recoveries at three spiked levels of 2, 20 and 200 microg/kg were in the range from 71.4% to 89.8% with the relative standard deviations (RSDs, n = 6) from 0.7% to 13.2% under the selected conditions. The limits of quantification (LOQ, S/N = 10) of aldicarb, aldicarb sulfone, and aldicarb sulfoxide in ginger were 1.0, 2.0 and 1.0 microg/kg, respectively. The results demonstrate that the developed method is rapid, cost-effective, and can meet the requirements of the multiple pesticide residue analysis. The method is applicable to determine aldicarb and its metabolites in ginger.

  12. Rapid screening method for quinolone residues in livestock and fishery products using immobilised metal chelate affinity chromatographic clean-up and liquid chromatography-fluorescence detection.

    PubMed

    Takeda, N; Gotoh, M; Matsuoka, T

    2011-09-01

    An efficient LC method was developed for screening the presence of quinolones (QLs)--comprising fluoroquinolones (FQs) and acidic quinolones (AQs)--residues in various livestock and fishery products. Targeted analytes were for nine FQs of marbofloxacin (MAR), ofloxacin (OFL), norfloxacin (NOR), ciprofloxacin (CIP), enrofloxacin (ENR), danofloxacin (DAN), orbifloxacin (ORB), difloxacin (DIF) and sarafloxacin (SAR), and three AQs of oxolinic acid (OXA), nalidixic acid (NAL) and flumequine (FMQ). Samples comprised ten different food products covering five matrices: muscle (cattle, swine and chicken), liver (chicken), raw fish (shrimp and salmon), egg (chicken), and processed food (ham, sausage and fish sausage). This method involved a simple extraction with (1:1) acetonitrile-methanol, a highly selective clean-up with an immobilised metal chelate affinity column charged with Fe(3+), a fast isocratic LC analysis using a short column (20 mm × 4.6 mm, 3 µm) with a mobile phase of (15:85:0.1) methanol/water/formic acid, and fluorescence detection (excitation/emission wavelengths of 295 nm/455 nm for FQs (495 nm for MAR), and 320 nm/365 nm for AQs). Among FQs, pairs of NOR/OFL, ORB/DIF and ENR/DAN were incompletely resolved. A confirmatory LC run with a Mg(2+) containing methanolic mobile phase was also proposed for the samples suspected of being positive. The optimised method gave satisfactory recoveries of 88.5% (56.1-108.6%) and 78.7% (44.1-99.5%) for intra- and inter-day assays with relative standard deviations of 7.2% (0.7-18.4%) and 6.8% (1.4-16.6%), respectively. Limits of quantitation ranged from 0.8 µg kg(-1) (DAN) to 6.5 µg kg(-1) (SAR). This method was successfully employed to analyse 113 real samples and two positive samples were found: fish sausage (CIP 990 µg kg(-1)) and shrimp (ENR 20 µg kg(-1)).

  13. Rapid screening method for quinolone residues in livestock and fishery products using immobilised metal chelate affinity chromatographic clean-up and liquid chromatography-fluorescence detection.

    PubMed

    Takeda, N; Gotoh, M; Matsuoka, T

    2011-09-01

    An efficient LC method was developed for screening the presence of quinolones (QLs)--comprising fluoroquinolones (FQs) and acidic quinolones (AQs)--residues in various livestock and fishery products. Targeted analytes were for nine FQs of marbofloxacin (MAR), ofloxacin (OFL), norfloxacin (NOR), ciprofloxacin (CIP), enrofloxacin (ENR), danofloxacin (DAN), orbifloxacin (ORB), difloxacin (DIF) and sarafloxacin (SAR), and three AQs of oxolinic acid (OXA), nalidixic acid (NAL) and flumequine (FMQ). Samples comprised ten different food products covering five matrices: muscle (cattle, swine and chicken), liver (chicken), raw fish (shrimp and salmon), egg (chicken), and processed food (ham, sausage and fish sausage). This method involved a simple extraction with (1:1) acetonitrile-methanol, a highly selective clean-up with an immobilised metal chelate affinity column charged with Fe(3+), a fast isocratic LC analysis using a short column (20 mm × 4.6 mm, 3 µm) with a mobile phase of (15:85:0.1) methanol/water/formic acid, and fluorescence detection (excitation/emission wavelengths of 295 nm/455 nm for FQs (495 nm for MAR), and 320 nm/365 nm for AQs). Among FQs, pairs of NOR/OFL, ORB/DIF and ENR/DAN were incompletely resolved. A confirmatory LC run with a Mg(2+) containing methanolic mobile phase was also proposed for the samples suspected of being positive. The optimised method gave satisfactory recoveries of 88.5% (56.1-108.6%) and 78.7% (44.1-99.5%) for intra- and inter-day assays with relative standard deviations of 7.2% (0.7-18.4%) and 6.8% (1.4-16.6%), respectively. Limits of quantitation ranged from 0.8 µg kg(-1) (DAN) to 6.5 µg kg(-1) (SAR). This method was successfully employed to analyse 113 real samples and two positive samples were found: fish sausage (CIP 990 µg kg(-1)) and shrimp (ENR 20 µg kg(-1)). PMID:21749230

  14. Cleaning up Floor Care.

    ERIC Educational Resources Information Center

    Carr, Richard; McLean, Doug

    1995-01-01

    Discusses how educational-facility maintenance departments can cut costs in floor cleaning through careful evaluation of floor equipment and products. Tips for choosing carpet detergents are highlighted. (GR)

  15. Cleaning up underground contaminants

    SciTech Connect

    Not Available

    1994-05-01

    At hundreds of industrial and government sites across the United States, environmental consulting firms are designing permanent containment systems for underground contaminants such as hydrocarbon fuels, cleaning solvents, and industrial chemicals. In quantities of thousands of liters or more, these chemicals threaten to contaminate drinking water supplies for hundreds of years. Typical containment systems (e.g., deep wells of cement or clay, or hydraulic pumping to control groundwater movement) can keep the chemicals from further contaminating groundwater if they are properly maintained for many years, but they do not remove the contaminants. Clearly, removing the contaminants from the soil is a much preferable solution than containing them and attempting to prevent their spread. A dynamic underground stripping process that combines steam and electrical heating of underground soils with vacuum extraction of vapors and fluids and guiding these processes by real-time monitoring methods is described.

  16. Cleaning Up Your Environment

    ERIC Educational Resources Information Center

    Feldman, Sandra

    2004-01-01

    In this article the author discusses how inadequate ventilation, poor air quality, mold and other conditions can have a detrimental impact on the health of students and school staff. She states that, these unsafe environmental conditions can cause a negative effect on students' health as well as their achievement. Furthermore, she discusses…

  17. Cleaning up Silicon

    NASA Technical Reports Server (NTRS)

    2000-01-01

    A development program that started in 1975 between Union Carbide and JPL, led to Advanced Silicon Materials LLC's, formerly ASiMI, commercial process for producing silane in viable quantities. The process was expanded to include the production of high-purity polysilicon for electronic devices. The technology came out of JPL's Low Cost Silicon Array Project.

  18. CLEAN-UP Act

    THOMAS, 112th Congress

    Sen. Mikulski, Barbara A. [D-MD

    2011-05-12

    05/12/2011 Read twice and referred to the Committee on Homeland Security and Governmental Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

  19. Cleaning up with sunshine

    SciTech Connect

    Goswami, D.Y.; Blake, D.M.

    1996-08-01

    This article describes how solar photocatalytic technology can be an effective method of breaking up toxic chemicals and disinfecting both water and air. The use of solar energy for the production of food, fiber, and heat has been known to mankind for a long time. Research over the last five decades has also made it possible to produce mechanical and electrical power with solar energy. And although the potential of solar radiation for disinfection and environmental mitigation has been known for years, only recently has this technology been scientifically recognized and researched. For anyone who has observed colors fading over long exposure to sunlight, certain materials deteriorating in the sunlight, or skin getting sunburned, it is not hard to imagine sunlight causing reactions that could be used beneficially to break up toxic chemicals. Older civilizations considered it essential that human dwellings be designed to allow sunshine in. This may have been for disinfection or to keep the growth of microorganisms in check. Research over the last three decades has not only confirmed the capability of sunlight for detoxification and disinfection but also accelerated the natural process by the use of catalysts. When sunlight is used to break up toxic chemicals by direct absorption through the chemical surface, the process is called photolysis. If the objective is achieved by the use of catalysts, it is known as photocatalysis. Recent research has concentrated mainly on photocatalytic detoxification and disinfection.

  20. Cleaning Up the Environment

    ERIC Educational Resources Information Center

    Pruett, Don; Pruett, Lindsay

    2005-01-01

    Environmental community service projects provide many opportunities for students to help the environment and connect with their communities. In Washington State, students are allowed to obtain a high school varsity letter in community service if they complete over 150 community service hours in a calendar year. To help students toward this goal,…

  1. Oil spill clean up

    SciTech Connect

    Claxton, L.D.; Houk, V.S.; Williams, R.; Kremer, F.

    1991-01-01

    Due to the consideration of bioremediation for oil spills, it is important to understand the ecological and human health implications of bioremediation efforts. During biodegradation, the toxicity of the polluting material may actually increase upon the conversion of non-toxic constituents to toxic species. Also, toxic compounds refractory to biological degradation may compromise the effectiveness of the treatment technique. In the study, the Salmonella mutagenicity assay showed that both the Prudhoe Bay crude oil and its weathered counterpart collected from oil-impacted water were weakly mutagenic. Results also showed that the mutagenic components were depleted at a faster rate than the overall content of organic material.

  2. Cleaning Up High.

    ERIC Educational Resources Information Center

    Rittner-Heir, Robbin M.

    2001-01-01

    Discusses cleaning techniques and equipment for areas in a school that are hard to reach, such as the high spacious ceilings, the tall windows of a school atrium, and high points in gymnasiums and auditoriums. (GR)

  3. Cleaning up the House

    SciTech Connect

    Hogue, C.

    2007-12-15

    Under the new 'Green the Capital' initiative, measures are making the House of Representatives a more energy efficient workplace. The Capital power plant, which burns mostly coal and natural gas to heat seven boilers, must operate in a carbon-neutral fashion by the end of 2008, by increasing energy efficiency and fuel switching. Roughly 103,000 MW hours of electricity will be bought each year from solar and wind-powered sources. Other measures being implemented are use of fluorescent light bulbs and recycled paper, and a boost in recycling of materials. 4 photos.

  4. Electrical field assisted matrix solid phase dispersion as a powerful tool to improve the extraction efficiency and clean-up of fluoroquinolones in bovine milk.

    PubMed

    da Silva, Mariana Cristina; Orlando, Ricardo Mathias; Faria, Adriana Ferreira

    2016-08-26

    This work presents a new method by electrical matrix solid phase dispersion for the extraction and clean-up of marbofloxacin, ofloxacin, norfloxacin, ciprofloxacin, enrofloxacin, difloxacin and sarafloxacin in bovine milk. Composition and pH of the eluent, applied electrical potential and polarity were optimized by experimental designs. The combination of the chromatographic and electrophoretic mechanisms allowed the extraction and clean-up in one step with low organic solvent consumption, high extraction throughput and elution automation. Linearity, precision, trueness and limit of quantification were evaluated and provided values in accordance with other methods recently developed for the analysis of fluoroquinolones in milk. This technique proved to be promising for the extraction and clean-up of ionizable analytes in different milk matrices.

  5. Additive quantification on polymer thin films by ToF-SIMS: aging sample effects

    NASA Astrophysics Data System (ADS)

    Poleunis, Claude; Médard, Nicolas; Bertrand, Patrick

    2004-06-01

    Thin films (150 nm) of an amorphous polyester (polyethylene(terephthalate-isophthalate)) containing variable concentrations of an antioxidant (Irgafos™ 168) and a UV-stabilizer (Hostavin™ N30) have been prepared by spin-coating. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) results showed, in the case of a single additive system (antioxidant), that the additive intensity increased on the polymer surface during the first five aging days (exudation phenomenon), followed by an intensity decrease, which was related to the adsorption of hydrocarbon contaminations on the sample surface. This kinetic competition was observed whatever the used additive concentration. In the case of the binary additive system (antioxidant and UV-stabilizer), the antioxidant behavior was similar to the single additive system, whereas, the UV-stabilizer evolution corresponded to an additive depletion, followed by an exudation. These results indicate that it is necessary to be very careful when comparing ToF-SIMS data for additive quantification on polymer surfaces. It is strongly recommended to compare samples having the same aging time, because the surface composition was seen to be strongly dependent of the aging time.

  6. 31. VIEW FROM SOUTHWEST TO CORNER WHERE SAMPLING/CRUSHING ADDITIONS ABUT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    31. VIEW FROM SOUTHWEST TO CORNER WHERE SAMPLING/CRUSHING ADDITIONS ABUT CRUSHED OXIDIZED ORE BIN. INTACT BARREN SOLUTION TANK VISIBLE IN FRONT OF CRUSHED ORE BIN. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  7. Studies of levels of biogenic amines in meat samples in relation to the content of additives.

    PubMed

    Jastrzębska, Aneta; Kowalska, Sylwia; Szłyk, Edward

    2016-01-01

    The impact of meat additives on the concentration of biogenic amines and the quality of meat was studied. Fresh white and red meat samples were fortified with the following food additives: citric and lactic acids, disodium diphosphate, sodium nitrite, sodium metabisulphite, potassium sorbate, sodium chloride, ascorbic acid, α-tocopherol, propyl 3,4,5-trihydroxybenzoate (propyl gallate) and butylated hydroxyanisole. The content of spermine, spermidine, putrescine, cadaverine, histamine, tyramine, tryptamine and 2-phenylethylamine was determined by capillary isotachophoretic methods in meat samples (fresh and fortified) during four days of storage at 4°C. The results were applied to estimate the impact of the tested additives on the formation of biogenic amines in white and red meat. For all tested meats, sodium nitrite, sodium chloride and disodium diphosphate showed the best inhibition. However, cadaverine and putrescine were characterised by the biggest changes in concentration during the storage time of all the additives. Based on the presented data for the content of biogenic amines in meat samples analysed as a function of storage time and additives, we suggest that cadaverine and putrescine have a significant impact on meat quality. PMID:26515667

  8. Studies of levels of biogenic amines in meat samples in relation to the content of additives.

    PubMed

    Jastrzębska, Aneta; Kowalska, Sylwia; Szłyk, Edward

    2016-01-01

    The impact of meat additives on the concentration of biogenic amines and the quality of meat was studied. Fresh white and red meat samples were fortified with the following food additives: citric and lactic acids, disodium diphosphate, sodium nitrite, sodium metabisulphite, potassium sorbate, sodium chloride, ascorbic acid, α-tocopherol, propyl 3,4,5-trihydroxybenzoate (propyl gallate) and butylated hydroxyanisole. The content of spermine, spermidine, putrescine, cadaverine, histamine, tyramine, tryptamine and 2-phenylethylamine was determined by capillary isotachophoretic methods in meat samples (fresh and fortified) during four days of storage at 4°C. The results were applied to estimate the impact of the tested additives on the formation of biogenic amines in white and red meat. For all tested meats, sodium nitrite, sodium chloride and disodium diphosphate showed the best inhibition. However, cadaverine and putrescine were characterised by the biggest changes in concentration during the storage time of all the additives. Based on the presented data for the content of biogenic amines in meat samples analysed as a function of storage time and additives, we suggest that cadaverine and putrescine have a significant impact on meat quality.

  9. Tackling the challenge of selective analytical clean-up of complex natural extracts: the curious case of chlorophyll removal.

    PubMed

    Bijttebier, Sebastiaan; D'Hondt, Els; Noten, Bart; Hermans, Nina; Apers, Sandra; Voorspoels, Stefan

    2014-11-15

    Alkaline saponification is often used to remove interfering chlorophylls and lipids during carotenoids analysis. However, saponification also hydrolyses esterified carotenoids and is known to induce artifacts. To avoid carotenoid artifact formation during saponification, Larsen and Christensen (2005) developed a gentler and simpler analytical clean-up procedure involving the use of a strong basic resin (Ambersep 900 OH). They hypothesised a saponification mechanism based on their Liquid Chromatography-Photodiode Array (LC-PDA) data. In the present study, we show with LC-PDA-accurate mass-Mass Spectrometry that the main chlorophyll removal mechanism is not based on saponification, apolar adsorption or anion exchange, but most probably an adsorption mechanism caused by H-bonds and dipole-dipole interactions. We showed experimentally that esterified carotenoids and glycerolipids were not removed, indicating a much more selective mechanism than initially hypothesised. This opens new research opportunities towards a much wider scope of applications (e.g. the refinement of oils rich in phytochemical content).

  10. A probabilistic model estimating oil spill clean-up costs--a case study for the Gulf of Finland.

    PubMed

    Montewka, Jakub; Weckström, Mia; Kujala, Pentti

    2013-11-15

    Existing models estimating oil spill costs at sea are based on data from the past, and they usually lack a systematic approach. This make them passive, and limits their ability to forecast the effect of the changes in the oil combating fleet or location of a spill on the oil spill costs. In this paper we make an attempt towards the development of a probabilistic and systematic model estimating the costs of clean-up operations for the Gulf of Finland. For this purpose we utilize expert knowledge along with the available data and information from literature. Then, the obtained information is combined into a framework with the use of a Bayesian Belief Networks. Due to lack of data, we validate the model by comparing its results with existing models, with which we found good agreement. We anticipate that the presented model can contribute to the cost-effective oil-combating fleet optimization for the Gulf of Finland. It can also facilitate the accident consequences estimation in the framework of formal safety assessment (FSA).

  11. Using integrated geospatial mapping and conceptual site models to guide risk-based environmental clean-up decisions.

    PubMed

    Mayer, Henry J; Greenberg, Michael R; Burger, Joanna; Gochfield, Michael; Powers, Charles; Kosson, David; Keren, Roger; Danis, Christine; Vyas, Vikram

    2005-04-01

    Government and private sector organizations are increasingly turning to the use of maps and other visual models to provide a depiction of environmental hazards and the potential risks they represent to humans and ecosystems. Frequently, the graphic presentation is tailored to address a specific contaminant, its location and possible exposure pathways, and potential receptors. Its format is usually driven by the data available, choice of graphics technology, and the audience being served. A format that is effective for displaying one contaminant at one scale at one site, however, may be ineffective in accurately portraying the circumstances surrounding a different contaminant at the same site, or the same contaminant at a different site, because of limitations in available data or the graphics technology being used. This is the daunting challenge facing the U.S. Department of Energy (DOE), which is responsible for the nation's legacy wastes from nuclear weapons research, testing, and production at over 100 sites in the United States. In this article, we discuss the development and use of integrated geospatial mapping and conceptual site models to identify hazards and evaluate alternative long-term environmental clean-up strategies at DOE sites located across the United States. While the DOE probably has the greatest need for such information, the Department of Defense and other public and private responsible parties for many large and controversial National Priority List or Superfund sites would benefit from a similar approach.

  12. Physicochemical regeneration of high silica zeolite Y used to clean-up water polluted with sulfonamide antibiotics.

    PubMed

    Braschi, I; Blasioli, S; Buscaroli, E; Montecchio, D; Martucci, A

    2016-05-01

    High silica zeolite Y has been positively evaluated to clean-up water polluted with sulfonamides, an antibiotic family which is known to be involved in the antibiotic resistance evolution. To define possible strategies for the exhausted zeolite regeneration, the efficacy of some chemico-physical treatments on the zeolite loaded with four different sulfonamides was evaluated. The evolution of photolysis, Fenton-like reaction, thermal treatments, and solvent extractions and the occurrence in the zeolite pores of organic residues eventually entrapped was elucidated by a combined thermogravimetric (TGA-DTA), diffractometric (XRPD), and spectroscopic (FT-IR) approach. The chemical processes were not able to remove the organic guest from zeolite pores and a limited transformation on embedded molecules was observed. On the contrary, both thermal treatment and solvent extraction succeeded in the regeneration of the zeolite loaded from deionized and natural fresh water. The recyclability of regenerated zeolite was evaluated over several adsorption/regeneration cycles, due to the treatment efficacy and its stability as well as the ability to regain the structural features of the unloaded material. PMID:27155437

  13. Tackling the challenge of selective analytical clean-up of complex natural extracts: the curious case of chlorophyll removal.

    PubMed

    Bijttebier, Sebastiaan; D'Hondt, Els; Noten, Bart; Hermans, Nina; Apers, Sandra; Voorspoels, Stefan

    2014-11-15

    Alkaline saponification is often used to remove interfering chlorophylls and lipids during carotenoids analysis. However, saponification also hydrolyses esterified carotenoids and is known to induce artifacts. To avoid carotenoid artifact formation during saponification, Larsen and Christensen (2005) developed a gentler and simpler analytical clean-up procedure involving the use of a strong basic resin (Ambersep 900 OH). They hypothesised a saponification mechanism based on their Liquid Chromatography-Photodiode Array (LC-PDA) data. In the present study, we show with LC-PDA-accurate mass-Mass Spectrometry that the main chlorophyll removal mechanism is not based on saponification, apolar adsorption or anion exchange, but most probably an adsorption mechanism caused by H-bonds and dipole-dipole interactions. We showed experimentally that esterified carotenoids and glycerolipids were not removed, indicating a much more selective mechanism than initially hypothesised. This opens new research opportunities towards a much wider scope of applications (e.g. the refinement of oils rich in phytochemical content). PMID:24912710

  14. Simultaneous multi-mycotoxin determination in nutmeg by ultrasound-assisted solid-liquid extraction and immunoaffinity column clean-up coupled with liquid chromatography and on-line post-column photochemical derivatization-fluorescence detection.

    PubMed

    Kong, Wei-Jun; Liu, Shu-Yu; Qiu, Feng; Xiao, Xiao-He; Yang, Mei-Hua

    2013-05-01

    A simple and sensitive analytical method based on ultrasound-assisted solid-liquid extraction and immunoaffinity column clean-up coupled with high performance liquid chromatography and on-line post-column photochemical derivatization-fluorescence detection (USLE-IAC-HPLC-PCD-FLD) has been developed for simultaneous multi-mycotoxin determination of aflatoxins B1, B2, G1, G2 (AFB1, AFB2, AFG1, AFG2) and ochratoxin A (OTA) in 13 edible and medicinal nutmeg samples marketed in China. AFs and OTA were extracted from nutmeg samples by ultrasonication using a methanol : water (80 : 20, v/v) solution, followed by an IAC clean-up step. Different USL extraction conditions, pre-processing ways for nutmeg sample and clean-up columns for mycotoxins, as well as HPLC-PCD-FLD parameters (mobile phase, column temperature, elution procedure, excitation and emission wavelengths) were optimized. This method, which was appraised for analyzing nutmeg samples, showed satisfactory results with reference to limits of detection (LODs) (from 0.02 to 0.25 μg kg(-1)), limits of quantification (LOQs) (from 0.06 to 0.8 μg kg(-1)), linear ranges (up to 30 ng mL(-1) for AFB1, AFG1 and OTA and 9 ng mL(-1) for AFB2 and AFG2), intra- and inter-day variability (all <2%) and average recoveries (from 79.6 to 90.8% for AFs and from 93.6 to 97.3% for OTA, respectively). The results of the application of developed method in nutmeg samples have elucidated that four samples were detected with contamination of AFs and one with OTA. AFB1 was the most frequently found mycotoxin in 30.8% of nutmeg samples at contamination levels of 0.73-16.31 μg kg(-1). At least two different mycotoxins were co-occurred in three samples, and three AFs were simultaneously detected in one sample.

  15. Simultaneous multi-mycotoxin determination in nutmeg by ultrasound-assisted solid-liquid extraction and immunoaffinity column clean-up coupled with liquid chromatography and on-line post-column photochemical derivatization-fluorescence detection.

    PubMed

    Kong, Wei-Jun; Liu, Shu-Yu; Qiu, Feng; Xiao, Xiao-He; Yang, Mei-Hua

    2013-05-01

    A simple and sensitive analytical method based on ultrasound-assisted solid-liquid extraction and immunoaffinity column clean-up coupled with high performance liquid chromatography and on-line post-column photochemical derivatization-fluorescence detection (USLE-IAC-HPLC-PCD-FLD) has been developed for simultaneous multi-mycotoxin determination of aflatoxins B1, B2, G1, G2 (AFB1, AFB2, AFG1, AFG2) and ochratoxin A (OTA) in 13 edible and medicinal nutmeg samples marketed in China. AFs and OTA were extracted from nutmeg samples by ultrasonication using a methanol : water (80 : 20, v/v) solution, followed by an IAC clean-up step. Different USL extraction conditions, pre-processing ways for nutmeg sample and clean-up columns for mycotoxins, as well as HPLC-PCD-FLD parameters (mobile phase, column temperature, elution procedure, excitation and emission wavelengths) were optimized. This method, which was appraised for analyzing nutmeg samples, showed satisfactory results with reference to limits of detection (LODs) (from 0.02 to 0.25 μg kg(-1)), limits of quantification (LOQs) (from 0.06 to 0.8 μg kg(-1)), linear ranges (up to 30 ng mL(-1) for AFB1, AFG1 and OTA and 9 ng mL(-1) for AFB2 and AFG2), intra- and inter-day variability (all <2%) and average recoveries (from 79.6 to 90.8% for AFs and from 93.6 to 97.3% for OTA, respectively). The results of the application of developed method in nutmeg samples have elucidated that four samples were detected with contamination of AFs and one with OTA. AFB1 was the most frequently found mycotoxin in 30.8% of nutmeg samples at contamination levels of 0.73-16.31 μg kg(-1). At least two different mycotoxins were co-occurred in three samples, and three AFs were simultaneously detected in one sample. PMID:23486692

  16. Effects of atmospheric precipitation additions on phytoplankton photosynthesis in Lake Michigan water samples

    SciTech Connect

    Parker, J.I.; Tisue, G.T.; Kennedy, C.W.; Seils, C.A.

    1981-01-01

    The effects of incremental additions (0.1 to 50% v/v) of atmospheric precipitation on phytoplankton photosynthesis (/sup 14/C uptake) were tested in Lake Michigan water samples. Wet deposition was used in experiments I, III, and IV, and a melted snow core was used in experiment II. Additions of precipitation significantly reduced photosynthesis in the first three experiments, starting at about the 5 to 15% treatment level. No significant difference occurred in experiment IV, but photosynthesis was greater than in the control samples and this precipitation sample appeared to stimulate primary productivity. Soluble reactive phosphate, nitrate, and ammonia levels in the precipitation samples exceeded the lake water averages by factors of 10, 2, and 50, respectively. Silicon levels in precipitation reduced pH very little and no consistent relationship was observed with reduced photosynthesis. Alkalinity was greatly reduced in the treated samples and special precautions were required in ce, Ti, Be, Co, Cu, Mo, Ni, P,f the Pd crystals of about 30 A. Possible mechanisms are discussed for isotope exchange in CO molecules in these catalysts and for the promoting effect of Pd on the activity of CuO.

  17. A one-step extraction/clean-up method for determination of PCBs, PBDEs and HBCDs in environmental solid matrices.

    PubMed

    Abdallah, Mohamed Abou-Elwafa; Drage, Daniel; Harrad, Stuart

    2013-12-01

    A selective pressurized liquid extraction (S-PLE) method was developed for rapid determination of 3 classes of halogenated organic contaminants in indoor dust, soil and sediment samples. The optimised method used 3 : 2 v/v n-hexane-dichloromethane for extraction of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs). Extraction was performed at 90 °C for 5 min followed by 4 min static time under 1500 psi. Good recoveries of target analytes were obtained after 3 extraction cycles. In-cell cleanup was performed using 10 g of 44% H2SO4 acid silica and 5 g of florisil (secondary fat retainer), while copper powder was used to remove elemental sulfur. The method was validated using NIST SRM2585 and SRM 1941b in addition to an in-house previously characterised soil sample. Measured concentrations of target compounds showed good agreement with the certified values with RSD < 20% indicating the good accuracy and precision of the S-PLE method. Clean extracts provided low noise levels resulting in low method detection limits (<0.03 ng g(-1)) and LOQs (<0.1 ng g(-1)). The method developed was applied successfully to real environmental samples and it provided various advantages over traditional methods including reduced solvent consumption and analysis time, minimal sample contamination and high sample throughput which can be beneficial for environmental monitoring programs dealing with large numbers of samples.

  18. Additive non-uniform random sampling in superimposed fiber Bragg grating strain gauge

    NASA Astrophysics Data System (ADS)

    Ma, Y. C.; Liu, H. Y.; Yan, S. B.; Yang, Y. H.; Yang, M. W.; Li, J. M.; Tang, J.

    2013-05-01

    This paper demonstrates an additive non-uniform random sampling and interrogation method for dynamic and/or static strain gauge using a reflection spectrum from two superimposed fiber Bragg gratings (FBGs). The superimposed FBGs are designed to generate non-equidistant space of a sensing pulse train in the time domain during dynamic strain gauge. By combining centroid finding with smooth filtering methods, both the interrogation speed and accuracy are improved. A 1.9 kHz dynamic strain is measured by generating an additive non-uniform randomly distributed 2 kHz optical sensing pulse train from a mean 500 Hz triangular periodically changing scanning frequency.

  19. A method for the quantification of low concentration sulfamethazine residues in milk based on molecularly imprinted clean-up and surface preconcentration at a Nafion-modified glassy carbon electrode.

    PubMed

    Guzmán-Vázquez de Prada, A; Reviejo, A J; Pingarrón, J M

    2006-02-13

    An electrochemical method for the determination of sulfamethazine at a low concentration level (25 microgl(-1)) in milk is reported. The method involves sample clean-up and selective preconcentration of sulfamethazine with a molecularly imprinted polymer (MIP), and a further electrode surface preconcentration of the analyte at a Nafion-coated glassy carbon electrode (GCE). Square wave (SW) oxidative voltammetry of accumulated sulfamethazine was employed for its quantification. Sulfamethazine electrode preconcentration was carried out in 0.1 moll(-1) Britton-Robinson buffer of pH 1.5, and by applying 5 min of accumulation at open circuit. A linear calibration graph was obtained for sulfamethazine at the Nafion-modified GCE over the 1.0x10(-8) to 1.0x10(-6)moll(-1) concentration range, with a detection limit of 6.8x10(-9)moll(-1) (1.9 microgl(-1)). This detection limit is remarkably better than those reported previously in the literature using electroanalytical techniques. Although the detection limit achieved was sufficient to allow the direct determination of sulfamethazine at the concentration level required in milk, a sample clean-up was shown to be necessary to obtain analytically useful SW voltammograms. This was accomplished by processing the deproteinized milk through a cartridge containing a molecularly imprinted polymer for sulfamethazine, also allowing a selective preconcentration of the analyte. Elution of the analyte from the MIP cartridges was carried out with 2 ml of a (9:1) MeOH:acetic acid mixture. Determination of sulfamethazine in milk samples was accomplished by interpolation into a calibration graph constructed with sulfamethazine standard solutions which were subjected to the same procedure than the deproteinized milk samples. Results obtained for five samples, spiked at the 25 microgl(-1) level, showed a mean recovery of (100+/-3)%.

  20. On the asymptotic improvement of supervised learning by utilizing additional unlabeled samples - Normal mixture density case

    NASA Technical Reports Server (NTRS)

    Shahshahani, Behzad M.; Landgrebe, David A.

    1992-01-01

    The effect of additional unlabeled samples in improving the supervised learning process is studied in this paper. Three learning processes. supervised, unsupervised, and combined supervised-unsupervised, are compared by studying the asymptotic behavior of the estimates obtained under each process. Upper and lower bounds on the asymptotic covariance matrices are derived. It is shown that under a normal mixture density assumption for the probability density function of the feature space, the combined supervised-unsupervised learning is always superior to the supervised learning in achieving better estimates. Experimental results are provided to verify the theoretical concepts.

  1. Multiplex short tandem repeat amplification of low template DNA samples with the addition of proofreading enzymes.

    PubMed

    Davis, Carey P; Chelland, Lynzee A; Pavlova, Victoria R; Illescas, María J; Brown, Kelly L; Cruz, Tracey Dawson

    2011-05-01

    With <100 pg of template DNA, routine short tandem repeat (STR) analysis often fails, resulting in no or partial profiles and increased stochastic effects. To overcome this, some have investigated preamplification methods that include the addition of proofreading enzymes to the PCR cocktail. This project sought to determine whether adding proofreading polymerases directly in the STR amplification mixture would improve the reaction when little template DNA is available. Platinum Taq High Fidelity and GeneAmp High Fidelity were tested in Profiler Plus™ STR reactions alone and in combination with AmpliTaq(®) Gold. All reactions included the additional step of a post-PCR purification step. With both pristine low template DNA and casework samples, the addition of these polymerases resulted in comparable or no improvement in the STR amplification signal. Further, stochastic effects and artifacts were observed equally across all enzyme conditions. Based on these studies, the addition of these proofreading enzymes to a multiplex STR amplification is not recommended for low template DNA work.

  2. A review of polymer nanofibres by electrospinning and their application in oil-water separation for cleaning up marine oil spills.

    PubMed

    Sarbatly, Rosalam; Krishnaiah, Duduku; Kamin, Zykamilia

    2016-05-15

    The growths of oil and gas exploration and production activities have increased environmental problems, such as oil spillage and the resulting pollution. The study of the methods for cleaning up oil spills is a critical issue to protect the environment. Various techniques are available to contain oil spills, but they are typically time consuming, energy inefficient and create secondary pollution. The use of a sorbent, such as a nanofibre sorbent, is a technique for controlling oil spills because of its good physical and oil sorption properties. This review discusses about the application of nanofibre sorbent for oil removal from water and its current developments. With their unique physical and mechanical properties coupled with their very high surface area and small pore sizes, nanofibre sorbents are alternative materials for cleaning up oil spills.

  3. A review of polymer nanofibres by electrospinning and their application in oil-water separation for cleaning up marine oil spills.

    PubMed

    Sarbatly, Rosalam; Krishnaiah, Duduku; Kamin, Zykamilia

    2016-05-15

    The growths of oil and gas exploration and production activities have increased environmental problems, such as oil spillage and the resulting pollution. The study of the methods for cleaning up oil spills is a critical issue to protect the environment. Various techniques are available to contain oil spills, but they are typically time consuming, energy inefficient and create secondary pollution. The use of a sorbent, such as a nanofibre sorbent, is a technique for controlling oil spills because of its good physical and oil sorption properties. This review discusses about the application of nanofibre sorbent for oil removal from water and its current developments. With their unique physical and mechanical properties coupled with their very high surface area and small pore sizes, nanofibre sorbents are alternative materials for cleaning up oil spills. PMID:27016959

  4. Enantioseparation and determination of triticonazole enantiomers in fruits, vegetables, and soil using efficient extraction and clean-up methods.

    PubMed

    Zhang, Qing; Gao, Beibei; Tian, Mingming; Shi, Haiyan; Hua, Xiude; Wang, Minghua

    2016-01-15

    An efficient and novel enantioseparation and determination method was developed to quantify the enantiomers of chiral triazole fungicide triticonazole in fruit, vegetable, and soil samples. Under the optimal chromatographic conditions, the enantiomers of triticonazole were completely enantioseparated on a cellulose tris(3-chloro-4-methyl phenyl carbamate) column with relatively good resolution (Rs=14.04). Two cleanup methods were compared to quantify the enantiomers of triticonazole. The modified QuEChERS (quick, easy, cheap, effective, rugged and safe) extraction procedure was achieved with sufficient recoveries and low detection limits. Good recoveries were obtained for the two enantiomers ranging from 84.1% to 103.2% in the six matrices, and the relative standard deviation values ranged from 1.7% to 8.4%. Under the optimal conditions, the obtained limits of detection (LODs) were in the range of 0.0012-0.0031mg/kg for the two enantiomers, and the limits of quantification (LOQs) were in the range of 0.0036-0.0091mg/kg, which were lower than the maximum residue levels established in Japan. In addition, the stereochemical structure of triticonazole enantiomers were determined for the first time using a combination of experimental and predicted electronic circular dichroism (ECD) spectra. The first eluted enantiomer was confirmed to be (+)-(S)-triticonazole. These results indicate that the proposed method is convenient and reliable for the enantioselective detection of triticonazole in authentic samples. The proposed method could be widely applicable for investigating the stereoselective degradation of triticonazole in food and environmental matrices, providing additional information for reliable risk assessment of triazole fungicides. PMID:26724558

  5. Late effects of ionizing radiation on functional status of bronchopulmonary system in COPD patients among the clean-up workers of the Chornobyl NPP accident.

    PubMed

    Sushko, V O; Shvaiko, L I; Bazyka, K D

    2014-09-01

    The objective of the study was to determine the effects of ionizing radiation on the functional condition of the bronchopulmonary system in clean-up workers of Chornobyl NPP patients with COPD in a remote post-emergency period. Materials and methods. The study of functional characteristics was carried out in 272 patients - 197 clean-up workers of Chornobyl NPP accident (ChNPPA) with radiation exposure from 25 to 988 mSv; 75 - group of nosological control and 20 healthy persons. Results and conclusions. For the clean-up workers of Chornobyl NPP with exposure doses over 500 mSv demonstrated correlation between respiratory function parameters and dose which is confirmed for these patients, compared with irradiated in doses less than 500 mSv and nosology control, a significant decreasing of VC (76,3 ± 8,5%, 82,4 ± 8,5% and 82,7 ± 8,1% accordingly, p <0,05), FVC (78,2 ± 8,3%, 84,3 ± 7,9% і 86,1 ± 9,7%, p <0,05), FEF 50 (26,1 ± 11,5%, 32,6 ± 10,6% і 32,1 ± 12,7%, p <0, 05) і FEF 75 (23,8 ± 8,1%, 27,8 ± 9,3% і 27,6 ± 9,2%, p <0,05). These changers combined with decrease in lung diffusion capacity in cases more than 500 mSv, and indicate severe respiratory disorders in patients with COPD among clean-up workers of ChNPPA.

  6. Role of radiation and non-radiation factors on the development of coronary heart disease in the Chornobyl clean-up workers: epidemiological study results.

    PubMed

    Krasnikova, L I; Buzunov, V O

    2014-09-01

    Objective. The objective of this study was to establish the risks for coronary heart disease in the Chornobyl clean-up workers with regard to a whole-body external radiation dose and non-radiation (biological, social-and-hygienic and behavioral) factors. Materials and methods. Risk-analysis was based on the cohort of the Chornobyl male clean-up workers 1986-1987 (8,625 men, including 3,623 with available whole-body external doses). Data of clinical-and-epidemiological registry, National Research Centre for Radiation Medicine were used for 1992-2013 monitoring period. We used the internal control group with radiation doses less than 0.05 Gy. Results. Statistically significant radiation risks in the Chornobyl clean-up workers were established for the coronary heart disease at doses 0.15-0.249 Gy, 0.25-0.99 Gy, 1 Gy and more (dose group 0.15-0.249 Gy RRY=1.9 (1.2; 3.1), ERR=4.6 (1.5; 14.9) Gy-1, EAR=64.2 cases per 1000 person-years, Gy); among exposed people aged 40 years and older - at doses 0.5-0.99 Gy (RRY=1.4 (1.05; 1.81), ERR=0.5 (0.03; 1.1) Gy-1, EAR=30.5 cases per 1000 person-years, Gy). Statistically significant risks for the disease under consideration were also identified with regard to non-radiation factors (smoking, improper physical training, adverse working conditions, diseases etc; age and psychoemotional overstrain were of a particular impact). Non-radiation factors are at most responsible for development of coronary heart disease. For this reason the control of potential confounding factors is required to assess the effect of the radiation factor both at a stage of comparison groups selection and analysis using the Mantel-Haenszel method.

  7. Evidence That Certain Waste Tank Headspace Vapor Samples Were Contaminated by Semivolatile Polymer Additives

    SciTech Connect

    Huckaby, James L.

    2006-02-09

    Vapor samples collected from the headspaces of the Hanford Site high-level radioactive waste tanks in 1994 and 1995 using the Vapor Sampling System (VSS) were reported to contain trace levels of phthalates, antioxidants, and certain other industrial chemicals that did not have a logical origin in the waste. This report examines the evidence these chemicals were sampling artifacts (contamination) and identifies the chemicals reported as headspace constituents that may instead have been contaminants. Specific recommendations are given regarding the marking of certain chemicals as suspect on the basis they were sampling manifold contaminants.

  8. 19 CFR 151.11 - Request for samples or additional examination packages after release of merchandise.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) EXAMINATION, SAMPLING... of this chapter. For purposes of determining admissibility, representatives of the Food and Drug Administration may obtain samples of any food, drug, device, or cosmetic, the importation of which is governed...

  9. 19 CFR 151.11 - Request for samples or additional examination packages after release of merchandise.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) EXAMINATION, SAMPLING... of this chapter. For purposes of determining admissibility, representatives of the Food and Drug Administration may obtain samples of any food, drug, device, or cosmetic, the importation of which is governed...

  10. 19 CFR 151.11 - Request for samples or additional examination packages after release of merchandise.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) EXAMINATION, SAMPLING... of this chapter. For purposes of determining admissibility, representatives of the Food and Drug Administration may obtain samples of any food, drug, device, or cosmetic, the importation of which is governed...

  11. 19 CFR 151.11 - Request for samples or additional examination packages after release of merchandise.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) EXAMINATION, SAMPLING... of this chapter. For purposes of determining admissibility, representatives of the Food and Drug Administration may obtain samples of any food, drug, device, or cosmetic, the importation of which is governed...

  12. CLEANING UP PESTICIDE CONTAMINATED SOILS: COMPARING EFFECTIVENESS OF SUPERCRITICAL FLUID EXTRACTION WITH SOLVENT EXTRACTION AND LOW TEMPERATURE THERMAL DESORPTION

    EPA Science Inventory

    Bench-scale supercritical fluid extraction (SFE) studies were performed on soil samples obtained from a Superfund site that is contaminated with high levels of p,p,-DDT, p,p,-DDD, p,p,-DDE, toxaphene and hexachlorocyclohexane. The effectiveness of supercritical fluid extraction ...

  13. Molecularly imprinted polymer beads for clean-up and preconcentration of β-lactamase-resistant penicillins in milk.

    PubMed

    Urraca, Javier L; Chamorro-Mendiluce, Raquel; Orellana, Guillermo; Moreno-Bondi, Maria C

    2016-03-01

    This work describes the development and application of class-selective molecularly imprinted polymers (MIPs) for the analysis of beta-lactamase-resistant penicillins, namely cloxacillin (CLOXA), oxacillin (OXA), and dicloxacillin (DICLOXA), in milk samples. Our method is based on molecularly imprinted solid-phase extraction (MISPE) coupled to high-performance liquid chromatography (HPLC) with diode-array detection (DAD). 2-Biphenylylpenicillin (2BPEN), a surrogate with a close resemblance to beta-lactamase-resistant penicillins in terms of size, shape, hydrophobicity, and functionality, was synthesized and used as the template for the polymer synthesis. A MIP library was prepared and screened to select the optimum functional monomer, N-(2-aminoethyl)methacrylamide, and cross-linker, trimethylolpropane trimethacrylate, that provided the best recognition for the target antibiotics. For the MISPE application, the MIPs were prepared in the form of microspheres, using porous silica beads (40-75 μm) as sacrificial scaffolds. The developed MISPE method enables efficient extraction from aqueous samples and analysis of the antimicrobials, when followed by a selective washing with 2 mL acetonitrile-water (20:80 v/v) and elution with 1 mL 0.05 mol L(-1) tetrabutylammonium in methanol. The analytical method was validated according to EU guideline 2002/657/EC. The limits of quantification (S/N = 10) were in the 5.3-6.3 μg kg(-1) range, well below the maximum residue limits (MRLs) currently established. Inter-day mean recoveries were in the range 99-102 % with RSDs below 9 %, improving on the performance of previously reported MISPE methods for the analysis of CLOXA, OXA, or DICLOXA in milk samples.

  14. Cleaning up the Legacy of the Cold War: Plutonium Oxides and the Role of Synchrotron Radiation Research

    SciTech Connect

    Clark, David Lewis

    2015-01-21

    The deceptively simple binary formula of AnO2 belies an incredibly complex structural nature, and propensity to form mixed-valent, nonstoichiometric phases of composition AnO2±x. For plutonium, the very formation of PuO2+x has challenged a long-established dogma, and raised fundamental questions for long-term storage and environmental migration. This presentation covers two aspects of Los Alamos synchrotron radiation studies of plutonium oxides: (1) the structural chemistry of laboratory-prepared AnO2+x systems (An = U, Pu; 0 ≤ x ≤ 0.25) determined through a combination of x-ray absorption fine structure spectroscopy (XAFS) and x-ray scattering of laboratory prepared samples; and (2) the application of synchrotron radiation towards the decontamination and decommissioning of the Rocky Flats Environmental Technology Site. Making the case for particle transport mechanisms as the basis of plutonium and americium mobility, rather than aqueous sorption-desorption processes, established a successful scientific basis for the dominance of physical transport processes by wind and water. The scientific basis was successful because it was in agreement with general theory on insolubility of PuO2 in oxidation state IV, results of ultrafiltration analyses of field water/sediment samples, XAFS analyses of soil, sediment, and concrete samples, and was also in general agreement with on-site monitoring data. This understanding allowed Site contractors to rapidly move to application of soil erosion and sediment transport models as the means of predicting plutonium and americium transport, which led to design and application of site-wide soil erosion control technology to help control downstream concentrations of plutonium and americium in streamflow.

  15. Radiation and non-radiation factors and their impact on the natural history of coronary heart disease in Chornobyl accident clean-up workers.

    PubMed

    Bilyi, D O; Nastina, O M; Gabulavichene, Zh M; Sydorenko, G V; Bazyka, O D; Bilaya, V V; Kovalyov, O S

    2014-09-01

    The objective of the study was to evaluate the impact of a range of risk factors and ionizing radiation on the severity of clinical presentation of coronary heart disease (CHD) in Chornobyl accident clean-up workers (ACW). Materials and methods. A total of 376 ACW and 123 Kiev city residents with no exposure to radiation participated in the study. Study scope included the case history recording, clinical check-up, electrocardiography (ECG), daily ECG-monitoring, daily arterial blood pressure monitoring, exercise ECG, Doppler ultrasound (Doppler echocardiography), and serum lipid profile assay. The severity of CHD was scored as a sum of functional class (FC) of angina pectoris and stage of heart failure (HF) to estimate the combined impact of several risk factors. Participation in the clean-up work, age, gender, body mass excess, hypercholesterolemia, CHD, diabetes mellitus (DM), survived myocardial infarction (MI) and acute cerebral stroke, heart rhythm abnormalities, and a complete bundle branch block were accounted as risk factors. Both separate and combined impact of those factors was assayed. The combined effect was scored as a sum where value zero corresponded to no sign and value one corresponded to its presence, whereas values from 1 to 4 explained the expression of a sign according to severity or stage of a disease according to contemporary classifications. Results and conclusions. Despite the fact that clinical characterization, functional state of cardiovascular system, and comorbidities in ACW were almost similar to that in control group the onset of CHD in ACW was significantly earlier (55.9 vs. 59.8 years old). According to Spearman's rank-order correlation data there was a reliable link of FC grades and HF severity values sum to the sum of indices scoring the age group of patients, their gender, presence of arterial hypertension, MI in a history, DM type 2, heart rhythm abnormalities, and a complete bundle branch block. Cluster of risk factors

  16. Radiation and non-radiation factors and their impact on the natural history of coronary heart disease in Chornobyl accident clean-up workers.

    PubMed

    Bilyi, D O; Nastina, O M; Gabulavichene, Zh M; Sydorenko, G V; Bazyka, O D; Bilaya, V V; Kovalyov, O S

    2014-09-01

    The objective of the study was to evaluate the impact of a range of risk factors and ionizing radiation on the severity of clinical presentation of coronary heart disease (CHD) in Chornobyl accident clean-up workers (ACW). Materials and methods. A total of 376 ACW and 123 Kiev city residents with no exposure to radiation participated in the study. Study scope included the case history recording, clinical check-up, electrocardiography (ECG), daily ECG-monitoring, daily arterial blood pressure monitoring, exercise ECG, Doppler ultrasound (Doppler echocardiography), and serum lipid profile assay. The severity of CHD was scored as a sum of functional class (FC) of angina pectoris and stage of heart failure (HF) to estimate the combined impact of several risk factors. Participation in the clean-up work, age, gender, body mass excess, hypercholesterolemia, CHD, diabetes mellitus (DM), survived myocardial infarction (MI) and acute cerebral stroke, heart rhythm abnormalities, and a complete bundle branch block were accounted as risk factors. Both separate and combined impact of those factors was assayed. The combined effect was scored as a sum where value zero corresponded to no sign and value one corresponded to its presence, whereas values from 1 to 4 explained the expression of a sign according to severity or stage of a disease according to contemporary classifications. Results and conclusions. Despite the fact that clinical characterization, functional state of cardiovascular system, and comorbidities in ACW were almost similar to that in control group the onset of CHD in ACW was significantly earlier (55.9 vs. 59.8 years old). According to Spearman's rank-order correlation data there was a reliable link of FC grades and HF severity values sum to the sum of indices scoring the age group of patients, their gender, presence of arterial hypertension, MI in a history, DM type 2, heart rhythm abnormalities, and a complete bundle branch block. Cluster of risk factors

  17. Analysis of Tank 43H Samples at the Conclusion of Uranyl Carbonate Addition

    SciTech Connect

    Oji, L.N.

    2002-10-15

    Tank 43H serves as the feed Tank to the 2H evaporator. In the months of July and August 2001, about 21,000 gallons of a depleted uranyl carbonate solution were added to Tank 43H and agitated with two Flygt mixers. The depleted uranium addition served to decrease the U-235 enrichment in the Tank 43H supernate so that the supernate could be evaporated with no risk of accumulating enriched uranium.

  18. Standard addition flow method for potentiometric measurements at low concentration levels: application to the determination of fluoride in food samples.

    PubMed

    Galvis-Sánchez, Andrea C; Santos, João Rodrigo; Rangel, António O S S

    2015-02-01

    A standard addition method was implemented by using a flow manifold able to perform automatically multiple standard additions and in-line sample treatment. This analytical strategy was based on the in-line mixing of sample and standard addition solutions, using a merging zone approach. The flow system aimed to exploit the standard addition method to quantify the target analyte particularly in cases where the analyte concentration in the matrix is below the lower limit of linear response of the detector. The feasibility of the proposed flow configuration was assessed through the potentiometric determination of fluoride in sea salts of different origins and different types of coffee infusions. The limit of quantification of the proposed manifold was 5×10(-6) mol L(-1), 10-fold lower than the lower limit of linear response of the potentiometric detector used. A determination rate of 8 samples h(-1) was achieved considering an experimental procedure based on three standard additions per sample. The main advantage of the proposed strategy is the simple approach to perform multiple standard additions, which can be implemented with other ion selective electrodes, especially in cases when the primary ion is below the lower limit of linear response of the detector.

  19. Environmental impact of a flocculant used to enhance solids transport during well bore clean-up operations

    SciTech Connect

    Yunus, M.N.M.; Procyk, A.D.; Malbrel, C.A.; Ling, K.L.C.

    1995-12-01

    This paper investigates particle flocculation as a mechanism to remove residual contaminants in well bores during completion operations. Laboratory tests and field trials were conducted demonstrating the ability of flocculating polymer sweeps to improve well bore cleaning efficiency. This process reduces the volume of fluid accumulated in the well bore that is discharged to the environment and minimizes the risk of formation damage by residuals left in the well bore. In addition, a comprehensive environmental impact study was performed on the flocculating polymers which included 72 hrs-EC50, 48 hrs-LC50, 10 day- LC50 tests on a variety of marine organisms, and bioaccumulation and biodegradability tests. In all cases, the flocculating polymers were shown to be environmentally safe at the recommended concentrations.

  20. Use of gel permeation chromatography for clean-up in the analysis of coccidiostats in eggs by liquid chromatography-tandem mass spectrometry.

    PubMed

    Chico, J; Rúbies, A; Centrich, F; Companyó, R; Prat, M D; Granados, M

    2013-05-01

    An analytical method for determination and confirmation of nine coccidiostatics in eggs is reported. Ethyl acetate is used as extraction solvent, with satisfactory results, and simple automated clean-up is based on gel-permeation chromatography (GPC) . The target compounds are then analysed by liquid chromatography-electrospray ionization-tandem mass spectrometry. The method was validated in-house in accordance with Commission Decision 2002/657/EC. Trueness and precision were determined at four concentrations, and the mean errors obtained were <10 %, with relative standard deviations ranging from 3 to 18 %. For three non-authorized coccidiostatics (clopidol, ethopabate, and ronizadole), decision limit and detection capability were in the ranges 0.12-0.16 and 0.18-0.23 μg kg(-1), respectively. The results obtained prove the suitability of this new analytical method for routine monitoring of these substances in eggs.

  1. Use of gel permeation chromatography for clean-up in the analysis of coccidiostats in eggs by liquid chromatography-tandem mass spectrometry.

    PubMed

    Chico, J; Rúbies, A; Centrich, F; Companyó, R; Prat, M D; Granados, M

    2013-05-01

    An analytical method for determination and confirmation of nine coccidiostatics in eggs is reported. Ethyl acetate is used as extraction solvent, with satisfactory results, and simple automated clean-up is based on gel-permeation chromatography (GPC) . The target compounds are then analysed by liquid chromatography-electrospray ionization-tandem mass spectrometry. The method was validated in-house in accordance with Commission Decision 2002/657/EC. Trueness and precision were determined at four concentrations, and the mean errors obtained were <10 %, with relative standard deviations ranging from 3 to 18 %. For three non-authorized coccidiostatics (clopidol, ethopabate, and ronizadole), decision limit and detection capability were in the ranges 0.12-0.16 and 0.18-0.23 μg kg(-1), respectively. The results obtained prove the suitability of this new analytical method for routine monitoring of these substances in eggs. PMID:23535744

  2. Inactivation of Geobacillus stearothermophilus in canned food and coconut milk samples by addition of enterocin AS-48.

    PubMed

    Viedma, Pilar Martínez; Abriouel, Hikmate; Ben Omar, Nabil; López, Rosario Lucas; Valdivia, Eva; Gálvez, Antonio

    2009-05-01

    The cyclic bacteriocin enterocin AS-48 was tested on a cocktail of two Geobacillus stearothermophilus strains in canned food samples (corn and peas), and in coconut milk. AS-48 (7 microg/g) reduced viable cell counts below detection levels in samples from canned corn and peas stored at 45 degrees C for 30 days. In coconut milk, bacterial inactivation by AS-48 (1.75 microg/ml) was even faster. In all canned food and drink samples inoculated with intact G. stearothermophilus endospores, bacteriocin addition (1.75 microg per g or ml of food sample) rapidly reduced viable cell counts below detection levels and avoided regrowth during storage. After a short-time bacteriocin treatment of endospores, trypsin addition markedly increased G. stearothermophilus survival, supporting the effect of residual bacteriocin on the observed loss of viability for endospores. Results from this study support the potential of enterocin AS-48 as a biopreservative against G. stearothermophilus. PMID:19269571

  3. The CERN antiproton source: Controls aspects of the additional collector ring and fast sampling devices

    NASA Astrophysics Data System (ADS)

    Chohan, V.

    1990-08-01

    The upgrade of the CERN antiproton source, meant to gain an order of magnitude in antiproton flux, required the construction of an additional ring to complement the existing antiproton accumulator (AA) and an entire rebuild of the target zone. The AA also needed major modifications to handle the increased flux and perform purely as an accumulator, preceded by collection in the collector ring (AC). The upgrade, known as the ACOL (antiproton collector) project, was approved under strict time and budgetary constraints and the existing AA control system, based on the Proton Synchrotron (PS) Divisional norms of CAMAC and Norsk-Data computers, had to be extended in the light of this. The limited (9 months) installation period for the whole upgrade meant that substantial preparatory and planning activities had to be carried out during the normal running of the AA. Advantage was taken of the upgrade to improve and consolidate the AA. Some aspects of the control system related to this upgrade are discussed together with the integration of new applications and instrumentation. The overall machine installation and running-in was carried out within the defined milestones and the project has now achieved the physics design goals.

  4. Apparatus for direct addition of reagents into a nuclear magnetic resonance (NMR) sample in the NMR probe

    NASA Astrophysics Data System (ADS)

    Perrin, Charles L.; Rivero, Ignacio A.

    1999-04-01

    Nuclear magnetic resonance (NMR) is a widely used tool in chemistry and biochemistry. It is occasionally necessary to add small aliquots of solvents or reagents repeatedly into the NMR tube. Ordinarily this is accomplished only by ejecting the sample and carrying out the addition outside the probe. It would be preferable to add the aliquot directly into the sample. We have designed and implemented a delivery system to accomplish this. This apparatus is particularly applicable to a recent NMR titration method for measuring relative pK's and to experiments where temperature must also be varied. This apparatus provides a safe, simple, and inexpensive method for repeated aliquot addition directly into the sample in the NMR probe.

  5. Development of a simple gel permeation clean-up procedure coupled to a rapid disequilibrium enzyme-linked immunosorbent assay (ELISA) for the detection of Sudan I dye in spices and sauces.

    PubMed

    Oplatowska, Michalina; Stevenson, Paul J; Schulz, Claudia; Hartig, Lutz; Elliott, Christopher T

    2011-09-01

    Sudan dyes have been found to be added to chilli and chilli products for illegal colour enhancement purposes. Due to the possible carcinogenic effect, they are not authorized to be used in food in the European Union or the USA. However, over the last few years, many products imported from Asian and African countries have been reported via the Rapid Alert System for Food and Feed in the European Union to be contaminated with these dyes. In order to provide fast screening method for the detection of Sudan I (SI), which is the most widely abused member of Sudan dyes family, a unique (20 min without sample preparation) direct disequilibrium enzyme-linked immunosorbent assay (ELISA) was developed. The assay was based on polyclonal antibodies highly specific to SI. A novel, simple gel permeation chromatography clean-up method was developed to purify extracts from matrices containing high amounts of fat and natural pigments, without the need for a large dilution of the sample. The assay was validated according to the Commission Decision 2002/657/EC criteria. The detection capability was determined to be 15 ng g(-1) in sauces and 50 ng g(-1) in spices. The recoveries found ranged from 81% to 116% and inter- and intra-assay coefficients of variation from 6% to 20%. The assay was used to screen a range of products (85 samples) collected from different retail sources within and outside the European Union. Three samples were found to contain high amounts (1,649, 722 and 1,461 ng g(-1)) of SI by ELISA. These results were confirmed by liquid chromatography-tandem mass spectrometry method. The innovative procedure allows for the fast, sensitive and high throughput screening of different foodstuffs for the presence of the illegal colorant SI.

  6. Are the Rich Cleaning Up?

    ERIC Educational Resources Information Center

    Murphy, Cait

    2000-01-01

    Discusses the dichotomy between new wealthy and not-so-wealthy people. Points out that the distance between the top and bottom tiers of income distribution has grown significantly since the 1970s. Looks at the reasons for the increase and what can be done about it. (JOW)

  7. Metalworkers clean up their waste

    SciTech Connect

    Valenti, M.

    1994-10-01

    This article describes how using methods such as chemical precipitation, filtration, and ion exchange, metal parts manufacturers are reducing the pollutants in their wastewater so it can be reused or safely discharged. Metalworking manufacturer are recovering useful materials, lowering their disposal costs, and reducing pollution by treating their wastewater with methods such as chemical precipitation and ion exchange so that it can be reused or safely discharged. They are also reducing wastes by recycling metalworking coolants. The major wastewater treatment technologies identified by the Environmental Protection Agency are chemical precipitation, or adding flocculants to bind waste particles together; membrane ultrafiltration and reverse osmosis, in which waste is trapped when the water passes through a membrane; and ion exchange, in which specially formulated resins capture dissolved metal salts. Other treatment techniques cited by Elwood Forsht, chief of the chemicals and metals branch at the EPA, include electrowinning, which uses electrolysis to concentrate metallic ions in wastewater, and coolant recycling, a method that removes metal particles by centrifugal force and kills bacteria by pasteurization. Many metalworking operations create wastewater, including drilling, welding, soldering, surface finishing, electroplating, acid treatment, anodizing, assembly, and machining. Companies use wastewater treatment technologies to recycle their wastewater or clean it so that it meets EPA standards and can be discharged into a municipal waste system, thus avoiding high disposal costs.

  8. Sample data processing in an additive and reproducible taxonomic workflow by using character data persistently linked to preserved individual specimens

    PubMed Central

    Kilian, Norbert; Henning, Tilo; Plitzner, Patrick; Müller, Andreas; Güntsch, Anton; Stöver, Ben C.; Müller, Kai F.; Berendsohn, Walter G.; Borsch, Thomas

    2015-01-01

    We present the model and implementation of a workflow that blazes a trail in systematic biology for the re-usability of character data (data on any kind of characters of pheno- and genotypes of organisms) and their additivity from specimen to taxon level. We take into account that any taxon characterization is based on a limited set of sampled individuals and characters, and that consequently any new individual and any new character may affect the recognition of biological entities and/or the subsequent delimitation and characterization of a taxon. Taxon concepts thus frequently change during the knowledge generation process in systematic biology. Structured character data are therefore not only needed for the knowledge generation process but also for easily adapting characterizations of taxa. We aim to facilitate the construction and reproducibility of taxon characterizations from structured character data of changing sample sets by establishing a stable and unambiguous association between each sampled individual and the data processed from it. Our workflow implementation uses the European Distributed Institute of Taxonomy Platform, a comprehensive taxonomic data management and publication environment to: (i) establish a reproducible connection between sampled individuals and all samples derived from them; (ii) stably link sample-based character data with the metadata of the respective samples; (iii) record and store structured specimen-based character data in formats allowing data exchange; (iv) reversibly assign sample metadata and character datasets to taxa in an editable classification and display them and (v) organize data exchange via standard exchange formats and enable the link between the character datasets and samples in research collections, ensuring high visibility and instant re-usability of the data. The workflow implemented will contribute to organizing the interface between phylogenetic analysis and revisionary taxonomic or monographic work

  9. Screening of pollution control and clean-up materials for river chemical spills using the multiple case-based reasoning method with a difference-driven revision strategy.

    PubMed

    Liu, Rentao; Jiang, Jiping; Guo, Liang; Shi, Bin; Liu, Jie; Du, Zhaolin; Wang, Peng

    2016-06-01

    In-depth filtering of emergency disposal technology (EDT) and materials has been required in the process of environmental pollution emergency disposal. However, an urgent problem that must be solved is how to quickly and accurately select the most appropriate materials for treating a pollution event from the existing spill control and clean-up materials (SCCM). To meet this need, the following objectives were addressed in this study. First, the material base and a case base for environment pollution emergency disposal were established to build a foundation and provide material for SCCM screening. Second, the multiple case-based reasoning model method with a difference-driven revision strategy (DDRS-MCBR) was applied to improve the original dual case-based reasoning model method system, and screening and decision-making was performed for SCCM using this model. Third, an actual environmental pollution accident from 2012 was used as a case study to verify the material base, case base, and screening model. The results demonstrated that the DDRS-MCBR method was fast, efficient, and practical. The DDRS-MCBR method changes the passive situation in which the choice of SCCM screening depends only on the subjective experience of the decision maker and offers a new approach to screening SCCM.

  10. A food web model of mercury transfer from stream sediment to predators of fish for ecological risk based clean-up goals

    SciTech Connect

    Burns, T.P.; Hadden, C.T.; Cornaby, B.W.; Mitz, S.V.

    1997-09-01

    A linear steady-state model of the food web linking sediment to piscivorous predators was used to derive ecological risk based clean-up concentrations for mercury in sediment of East Fork Poplar Creek (EFPC), Oak Ridge, TN. The model partitions aquatic invertebrates into two classes based on the primary source of exposure to mercury in sediment, and the prey-fish community into three classes based on differences in their diets and feeding habits. Biotransfer factors for the links between sediment and sediment-dwelling invertebrates, water and aquatic biota and fish, and prey and predators are published values. The model uses site specific data on the fraction of methylmercury in sediment, the relative abundance of prey fish, and the predicted flux of mercury from sediment. Monte Carlo analysis quantifies the uncertainty in the risk to top predators of fish. At 96 mg/kg mercury in sediment, less than 20% of the exposures exceed dietary limits for endpoint receptors. The fraction of methylmercury in sediment, the three biotransfer factors for methylmercury, and diet are sensitive parameters.

  11. A systematic assessment of the state of hazardous waste clean-up technologies. Quarterly technical progress report, April 1--June 30, 1993

    SciTech Connect

    Berg, M.T.; Reed, B.E.; Gabr, M.

    1993-07-01

    West Virginia University (WVU) and the US DOE Morgantown Energy Technology Center (METC) entered into a Cooperative Agreement on August 29, 1992 entitled ``Decontamination Systems Information and Research Programs.`` Stipulated within the Agreement is the requirement that WVU submit to METC a series of Technical Progress Report for Year 1 of the Agreement. This report reflects the progress and/or efforts performed on the following nine technical projects encompassed by the Year 1 Agreement for the period of April 1 through June 30, 1993: Systematic assessment of the state of hazardous waste clean-up technologies; site remediation technologies -- drain-enhanced soil flushing (DESF) for organic contaminants removal; site remediation technologies -- in situ bioremediation of organic contaminants; excavation systems for hazardous waste sites; chemical destruction of polychlorinated biphenyls; development of organic sensors -- monolayer and multilayer self-assembled films for chemical sensors; Winfield lock and dam remediation; Assessments of Technologies for hazardous waste site remediation -- non-treatment technologies and pilot scale test facility implementation; and remediation of hazardous sites with stream reforming.

  12. Tetrahydrofuran-water extraction, in-line clean-up and selective liquid chromatography/tandem mass spectrometry for the quantitation of perfluorinated compounds in food at the low picogram per gram level.

    PubMed

    Ballesteros-Gómez, Ana; Rubio, Soledad; van Leeuwen, Stefan

    2010-09-17

    A new solvent extraction system was developed for extraction of PFCs from food. The extraction is carried out with 75:25 (v/v) tetrahydrofuran:water, a solvent mixture that provides an appropriate balance of hydrogen bonding, dispersion and dipole-dipole interactions to efficiently extract PFCs with chains containing 4-14 carbon atoms from foods. This mixture provided recoveries above 85% from foods including vegetables, fruits, fish, meat and bread; and above 75% from cheese. Clean-up with a weak anion exchange resin and Envi-carb SPE, which were coupled in line for simplicity, was found to minimize matrix effects (viz. enhancement or suppression of electrospray ionization). The target analytes (PFCs) were resolved on a perfluorooctyl phase column that proved effective in separating mass interferences for perfluorooctane sulfonate (PFOS) in fish and meat samples. The mass spectrometer was operated in the negative electrospray ionization mode and used to record two transitions per analyte and one per mass-labeled method internal standard. The target PFCs were quantified from solvent based calibration curves. The limits of detection (LODs) were as low as 1-5 pg analyte g(-1) food; by exception, those for C(4) and C(5) PFCs were somewhat higher (25-30 pg g(-1)) owing to their less favourable mass response. To the best of our knowledge these are among the best LODs for PFCs in foods reported to date. The analysis of a variety of foods revealed contamination with PFCs at levels from 4.5 to 75 pg g(-1) in 25% of samples (fish and packaged spinach). C(10)-C(14) PFCs were found in fish, which testifies to the need to control long-chain PFCs in this type of food. The proposed method is a useful tool for the development of a large-scale database for the presence of PFCs in foods. PMID:20709322

  13. Particle size distribution and chemical composition of total mixed rations for dairy cattle: water addition and feed sampling effects.

    PubMed

    Arzola-Alvarez, C; Bocanegra-Viezca, J A; Murphy, M R; Salinas-Chavira, J; Corral-Luna, A; Romanos, A; Ruíz-Barrera, O; Rodríguez-Muela, C

    2010-09-01

    Four dairy farms were used to determine the effects of water addition to diets and sample collection location on the particle size distribution and chemical composition of total mixed rations (TMR). Samples were collected weekly from the mixing wagon and from 3 locations in the feed bunk (top, middle, and bottom) for 5 mo (April, May, July, August, and October). Samples were partially dried to determine the effect of moisture on particle size distribution. Particle size distribution was measured using the Penn State Particle Size Separator. Crude protein, neutral detergent fiber, and acid detergent fiber contents were also analyzed. Particle fractions 19 to 8, 8 to 1.18, and <1.18 mm were judged adequate in all TMR for rumen function and milk yield; however, the percentage of material>19 mm was greater than recommended for TMR, according to the guidelines of Cooperative Extension of Pennsylvania State University. The particle size distribution in April differed from that in October, but intermediate months (May, July, and August) had similar particle size distributions. Samples from the bottom of the feed bunk had the highest percentage of particles retained on the 19-mm sieve. Samples from the top and middle of the feed bunk were similar to that from the mixing wagon. Higher percentages of particles were retained on >19, 19 to 8, and 8 to 1.18 mm sieves for wet than dried samples. The reverse was found for particles passing the 1.18-mm sieve. Mean particle size was higher for wet than dried samples. The crude protein, neutral detergent fiber, and acid detergent fiber contents of TMR varied with month of sampling (18-21, 40-57, and 21-34%, respectively) but were within recommended ranges for high-yielding dairy cows. Analyses of TMR particle size distributions are useful for proper feed bunk management and formulation of diets that maintain rumen function and maximize milk production and quality. Water addition may help reduce dust associated with feeding TMR. PMID

  14. Rapid estimation of readily leachable triazine residues in soils using automatic kinetic bioaccessibility assays followed by on-line sorptive clean-up as a front-end to liquid chromatography.

    PubMed

    Vida, Ana C F; Cocovi-Solberg, David J; Zagatto, Elias A G; Miró, Manuel

    2016-08-15

    An automatic batchwise bioaccessibility test was proposed for on-line monitoring of readily mobile pools of ametryn and atrazine residues in agricultural soils with different physicochemical properties. A 0.01molL(-1) CaCl2 solution mimicking rainwater percolation through the soil profiles was used for the herbicide extractions. The extract aliquots were successively sampled at regular time intervals in order to investigate the extraction kinetics. For extract clean-up and retention of freely dissolved target species, 30mg of restricted-access like copolymer were used as in-line sorptive material followed by elution with methanol and on-line heart-cut injection towards a C18 silica reversed-phase monolithic column (100×4.6mm) in a liquid chromatographic system. A mathematical model emphasized that the readily available pools vs time can be in most instances described by a first-order exponential equation, thus an asymptotical value is approached. Consequently, the leaching assays can be performed without attaining chemical equilibrium. Enhancement factors and detection limits were 10.2 and 18.8, and 0.40 and 0.37mgkg(-1) for ametryn and atrazine, respectively. The automatic method features good repeatability for leaching tests (r.s.d.: 11.8-10.2% for sandy and 3.7-6.2% for clayey soil). Reliable data, demonstrated with relative recoveries in the soil leachates ranging from 86 to 104%, were achieved in less than 35min, thus avoiding the need for up to 24h as recommended by standard leaching methods. PMID:27260437

  15. Association between health information, use of protective devices and occurrence of acute health problems in the Prestige oil spill clean-up in Asturias and Cantabria (Spain): a cross-sectional study

    PubMed Central

    Carrasco, José Miguel; Lope, Virginia; Pérez-Gómez, Beatriz; Aragonés, Nuria; Suárez, Berta; López-Abente, Gonzalo; Rodríguez-Artalejo, Fernando; Pollán, Marina

    2006-01-01

    Background This paper examines the association between use of protective devices, frequency of acute health problems and health-protection information received by participants engaged in the Prestige oil spill clean-up in Asturias and Cantabria, Spain. Methods We studied 133 seamen, 135 bird cleaners, 266 volunteers and 265 paid workers selected by random sampling, stratified by type of worker and number of working days. Information was collected by telephone interview conducted in June 2003. The association of interest was summarized, using odds ratios (OR) obtained from logistic regression. Results Health-protection briefing was associated with use of protective devices and clothing. Uninformed subjects registered a significant excess risk of itchy eyes (OR:2.89; 95%CI:1.21–6.90), nausea/vomiting/dizziness (OR:2.25; 95%CI:1.17–4.32) and throat and respiratory problems (OR:2.30; 95%CI:1.15–4.61). There was a noteworthy significant excess risk of headaches (OR:3.86: 95%CI:1.74–8.54) and respiratory problems (OR:2.43; 95%CI:1.02–5.79) among uninformed paid workers. Seamen, the group most exposed to the fuel-oil, were the worst informed and registered the highest frequency of toxicological problems. Conclusion Proper health-protection briefing was associated with greater use of protective devices and lower frequency of health problems. Among seamen, however, the results indicate poorer dissemination of information and the need of specific guidelines for removing fuel-oil at sea. PMID:16390547

  16. Rapid estimation of readily leachable triazine residues in soils using automatic kinetic bioaccessibility assays followed by on-line sorptive clean-up as a front-end to liquid chromatography.

    PubMed

    Vida, Ana C F; Cocovi-Solberg, David J; Zagatto, Elias A G; Miró, Manuel

    2016-08-15

    An automatic batchwise bioaccessibility test was proposed for on-line monitoring of readily mobile pools of ametryn and atrazine residues in agricultural soils with different physicochemical properties. A 0.01molL(-1) CaCl2 solution mimicking rainwater percolation through the soil profiles was used for the herbicide extractions. The extract aliquots were successively sampled at regular time intervals in order to investigate the extraction kinetics. For extract clean-up and retention of freely dissolved target species, 30mg of restricted-access like copolymer were used as in-line sorptive material followed by elution with methanol and on-line heart-cut injection towards a C18 silica reversed-phase monolithic column (100×4.6mm) in a liquid chromatographic system. A mathematical model emphasized that the readily available pools vs time can be in most instances described by a first-order exponential equation, thus an asymptotical value is approached. Consequently, the leaching assays can be performed without attaining chemical equilibrium. Enhancement factors and detection limits were 10.2 and 18.8, and 0.40 and 0.37mgkg(-1) for ametryn and atrazine, respectively. The automatic method features good repeatability for leaching tests (r.s.d.: 11.8-10.2% for sandy and 3.7-6.2% for clayey soil). Reliable data, demonstrated with relative recoveries in the soil leachates ranging from 86 to 104%, were achieved in less than 35min, thus avoiding the need for up to 24h as recommended by standard leaching methods.

  17. Deriving site-specific soil clean-up values for metals and metalloids: rationale for including protection of soil microbial processes.

    PubMed

    Kuperman, Roman G; Siciliano, Steven D; Römbke, Jörg; Oorts, Koen

    2014-07-01

    Although it is widely recognized that microorganisms are essential for sustaining soil fertility, structure, nutrient cycling, groundwater purification, and other soil functions, soil microbial toxicity data were excluded from the derivation of Ecological Soil Screening Levels (Eco-SSL) in the United States. Among the reasons for such exclusion were claims that microbial toxicity tests were too difficult to interpret because of the high variability of microbial responses, uncertainty regarding the relevance of the various endpoints, and functional redundancy. Since the release of the first draft of the Eco-SSL Guidance document by the US Environmental Protection Agency in 2003, soil microbial toxicity testing and its use in ecological risk assessments have substantially improved. A wide range of standardized and nonstandardized methods became available for testing chemical toxicity to microbial functions in soil. Regulatory frameworks in the European Union and Australia have successfully incorporated microbial toxicity data into the derivation of soil threshold concentrations for ecological risk assessments. This article provides the 3-part rationale for including soil microbial processes in the development of soil clean-up values (SCVs): 1) presenting a brief overview of relevant test methods for assessing microbial functions in soil, 2) examining data sets for Cu, Ni, Zn, and Mo that incorporated soil microbial toxicity data into regulatory frameworks, and 3) offering recommendations on how to integrate the best available science into the method development for deriving site-specific SCVs that account for bioavailability of metals and metalloids in soil. Although the primary focus of this article is on the development of the approach for deriving SCVs for metals and metalloids in the United States, the recommendations provided in this article may also be applicable in other jurisdictions that aim at developing ecological soil threshold values for protection of

  18. Deriving site-specific soil clean-up values for metals and metalloids: rationale for including protection of soil microbial processes.

    PubMed

    Kuperman, Roman G; Siciliano, Steven D; Römbke, Jörg; Oorts, Koen

    2014-07-01

    Although it is widely recognized that microorganisms are essential for sustaining soil fertility, structure, nutrient cycling, groundwater purification, and other soil functions, soil microbial toxicity data were excluded from the derivation of Ecological Soil Screening Levels (Eco-SSL) in the United States. Among the reasons for such exclusion were claims that microbial toxicity tests were too difficult to interpret because of the high variability of microbial responses, uncertainty regarding the relevance of the various endpoints, and functional redundancy. Since the release of the first draft of the Eco-SSL Guidance document by the US Environmental Protection Agency in 2003, soil microbial toxicity testing and its use in ecological risk assessments have substantially improved. A wide range of standardized and nonstandardized methods became available for testing chemical toxicity to microbial functions in soil. Regulatory frameworks in the European Union and Australia have successfully incorporated microbial toxicity data into the derivation of soil threshold concentrations for ecological risk assessments. This article provides the 3-part rationale for including soil microbial processes in the development of soil clean-up values (SCVs): 1) presenting a brief overview of relevant test methods for assessing microbial functions in soil, 2) examining data sets for Cu, Ni, Zn, and Mo that incorporated soil microbial toxicity data into regulatory frameworks, and 3) offering recommendations on how to integrate the best available science into the method development for deriving site-specific SCVs that account for bioavailability of metals and metalloids in soil. Although the primary focus of this article is on the development of the approach for deriving SCVs for metals and metalloids in the United States, the recommendations provided in this article may also be applicable in other jurisdictions that aim at developing ecological soil threshold values for protection of

  19. Gasoline additives, emissions, and performance

    SciTech Connect

    1995-12-31

    The papers included in this publication deal with the influence of fuel, additive, and hardware changes on a variety of vehicle performance characteristics. Advanced techniques for measuring these performance parameters are also described. Contents include: Fleet test evaluation of gasoline additives for intake valve and combustion chamber deposit clean up; A technique for evaluating octane requirement additives in modern engines on dynamometer test stands; A fleet test of two additive technologies comparing their effects on tailpipe emissions; Investigation into the vehicle exhaust emissions of high percentage ethanol blends; Variability in hydrocarbon speciation measurements at low emission (ULEV) levels; and more.

  20. Estimation of a partially linear additive model for data from an outcome-dependent sampling design with a continuous outcome.

    PubMed

    Tan, Ziwen; Qin, Guoyou; Zhou, Haibo

    2016-10-01

    Outcome-dependent sampling (ODS) designs have been well recognized as a cost-effective way to enhance study efficiency in both statistical literature and biomedical and epidemiologic studies. A partially linear additive model (PLAM) is widely applied in real problems because it allows for a flexible specification of the dependence of the response on some covariates in a linear fashion and other covariates in a nonlinear non-parametric fashion. Motivated by an epidemiological study investigating the effect of prenatal polychlorinated biphenyls exposure on children's intelligence quotient (IQ) at age 7 years, we propose a PLAM in this article to investigate a more flexible non-parametric inference on the relationships among the response and covariates under the ODS scheme. We propose the estimation method and establish the asymptotic properties of the proposed estimator. Simulation studies are conducted to show the improved efficiency of the proposed ODS estimator for PLAM compared with that from a traditional simple random sampling design with the same sample size. The data of the above-mentioned study is analyzed to illustrate the proposed method.

  1. Estimation of a partially linear additive model for data from an outcome-dependent sampling design with a continuous outcome.

    PubMed

    Tan, Ziwen; Qin, Guoyou; Zhou, Haibo

    2016-10-01

    Outcome-dependent sampling (ODS) designs have been well recognized as a cost-effective way to enhance study efficiency in both statistical literature and biomedical and epidemiologic studies. A partially linear additive model (PLAM) is widely applied in real problems because it allows for a flexible specification of the dependence of the response on some covariates in a linear fashion and other covariates in a nonlinear non-parametric fashion. Motivated by an epidemiological study investigating the effect of prenatal polychlorinated biphenyls exposure on children's intelligence quotient (IQ) at age 7 years, we propose a PLAM in this article to investigate a more flexible non-parametric inference on the relationships among the response and covariates under the ODS scheme. We propose the estimation method and establish the asymptotic properties of the proposed estimator. Simulation studies are conducted to show the improved efficiency of the proposed ODS estimator for PLAM compared with that from a traditional simple random sampling design with the same sample size. The data of the above-mentioned study is analyzed to illustrate the proposed method. PMID:27006375

  2. Towards a phylogenetic generic classification of Thelypteridaceae: Additional sampling suggests alterations of neotropical taxa and further study of paleotropical genera.

    PubMed

    Almeida, Thaís Elias; Hennequin, Sabine; Schneider, Harald; Smith, Alan R; Batista, João Aguiar Nogueira; Ramalho, Aline Joseph; Proite, Karina; Salino, Alexandre

    2016-01-01

    Thelypteridaceae is one of the largest fern families, having about 950 species and a cosmopolitan distribution but with most species occurring in tropical and subtropical regions. Its generic classification remains controversial, with different authors recognizing from one up to 32 genera. Phylogenetic relationships within the family have not been exhaustively studied, but previous studies have confirmed the monophyly of the lineage. Thus far, sampling has been inadequate for establishing a robust hypothesis of infrafamilial relationships within the family. In order to understand phylogenetic relationships within Thelypteridaceae and thus to improve generic reclassification, we expand the molecular sampling, including new samples of Old World taxa and, especially, many additional neotropical representatives. We also explore the monophyly of exclusively or mostly neotropical genera Amauropelta, Goniopteris, Meniscium, and Steiropteris. Our sampling includes 68 taxa and 134 newly generated sequences from two plastid genomic regions (rps4-trnS and trnL-trnF), plus 73 rps4 and 72 trnL-trnF sequences from GenBank. These data resulted in a concatenated matrix of 1980 molecular characters for 149 taxa. The combined data set was analyzed using maximum parsimony and bayesian inference of phylogeny. Our results are consistent with the general topological structure found in previous studies, including two main lineages within the family: phegopteroid and thelypteroid. The thelypteroid lineage comprises two clades; one of these included the segregates Metathelypteris, Coryphopteris, and Amauropelta (including part of Parathelypteris), whereas the other comprises all segregates of Cyclosorus s.l., such as Goniopteris, Meniscium, and Steiropteris (including Thelypteris polypodioides, previously incertae sedis). The three mainly neotropical segregates were found to be monophyletic but nested in a broadly defined Cyclosorus. The fourth mainly neotropical segregate, Amauropelta

  3. Towards a phylogenetic generic classification of Thelypteridaceae: Additional sampling suggests alterations of neotropical taxa and further study of paleotropical genera.

    PubMed

    Almeida, Thaís Elias; Hennequin, Sabine; Schneider, Harald; Smith, Alan R; Batista, João Aguiar Nogueira; Ramalho, Aline Joseph; Proite, Karina; Salino, Alexandre

    2016-01-01

    Thelypteridaceae is one of the largest fern families, having about 950 species and a cosmopolitan distribution but with most species occurring in tropical and subtropical regions. Its generic classification remains controversial, with different authors recognizing from one up to 32 genera. Phylogenetic relationships within the family have not been exhaustively studied, but previous studies have confirmed the monophyly of the lineage. Thus far, sampling has been inadequate for establishing a robust hypothesis of infrafamilial relationships within the family. In order to understand phylogenetic relationships within Thelypteridaceae and thus to improve generic reclassification, we expand the molecular sampling, including new samples of Old World taxa and, especially, many additional neotropical representatives. We also explore the monophyly of exclusively or mostly neotropical genera Amauropelta, Goniopteris, Meniscium, and Steiropteris. Our sampling includes 68 taxa and 134 newly generated sequences from two plastid genomic regions (rps4-trnS and trnL-trnF), plus 73 rps4 and 72 trnL-trnF sequences from GenBank. These data resulted in a concatenated matrix of 1980 molecular characters for 149 taxa. The combined data set was analyzed using maximum parsimony and bayesian inference of phylogeny. Our results are consistent with the general topological structure found in previous studies, including two main lineages within the family: phegopteroid and thelypteroid. The thelypteroid lineage comprises two clades; one of these included the segregates Metathelypteris, Coryphopteris, and Amauropelta (including part of Parathelypteris), whereas the other comprises all segregates of Cyclosorus s.l., such as Goniopteris, Meniscium, and Steiropteris (including Thelypteris polypodioides, previously incertae sedis). The three mainly neotropical segregates were found to be monophyletic but nested in a broadly defined Cyclosorus. The fourth mainly neotropical segregate, Amauropelta

  4. Development of a liquid chromatography-tandem mass spectrometry with ultrasound-assisted extraction and auto solid-phase clean-up method for the determination of Fusarium toxins in animal derived foods.

    PubMed

    Chen, Dongmei; Cao, Xiaoqin; Tao, Yanfei; Wu, Qinghua; Pan, Yuanhu; Peng, Dapeng; Liu, Zhenli; Huang, Lingli; Wang, Yulian; Wang, Xu; Yuan, Zonghui

    2013-10-11

    A liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for the simultaneous determination of 19 Fusarium toxins and their metabolites including deoxynivalenol (DON), nivalenol (NIV), T-2 toxin (T-2), HT-2 toxin (HT-2), 3-acetyldeoxynivalenol (3-AcDON), 15-acetyldeoxynivalenol (15-AcDON), neosolaniol (NEO), fusarenon-X (F-X), diacetoxyscirpenol (DAS), monoacetoxyscirpenol (MAS), zearalanone (ZAN), zearalenone (ZON), α-Zearalenol (α-ZOL), β-Zearalenol (β-ZOL), a-Zearalanol (α-ZAL), β-Zearalanol (β-ZAL), T-2 triol, T-2 tetraol, deepoxy-deoxynialenol (DOM-1) in the muscle, liver, kidney, fat of swine, bovine and sheep, muscle and liver of chicken, muscle and skin of fish, as well as milk and eggs. Sample preparation procedure includes ultrasound-assisted extraction with acetonitrile/water (90/10, v/v), defatting with n-hexane and final clean-up with auto solid phase extraction (SPE) on Bond Elut Mycotoxin cartridges. The detection and quantification of the analytes were performed by a reversed-phase liquid chromatography coupled with electrospray ionization triple quadrupole mass spectrometry (LC/ESI-MS/MS). DON, NIV, DOM-1, 3-AcDON, 15-AcDON, F-X, ZON, ZAN, α-ZOL, β-ZOL, α-ZAL, β-ZAL, T-2 triol and T-2 tetraol were detected in a negative ion mode, while T-2 toxin, HT-2 toxin, NEO, DAS and MAS were detected in a positive ion mode. The CCα and CCβ of the analytes in different samples varied from 0.16 to 1.37μg/kg and 0.33 to 2.34μg/kg, respectively. The recoveries of spiked sample from 0.5μg/kg to 8μg/kg ranged from 64.8% to 108.2% with the relative standard deviations of less than 19.4%. Performances of the whole analytical procedure meet the criteria established by the European Commission for mass spectrometric detection.

  5. Growth and parameters of microflora in intestinal and faecal samples of piglets due to application of a phytogenic feed additive.

    PubMed

    Muhl, A; Liebert, F

    2007-10-01

    A commercial phytogenic feed additive (PFA), containing the fructopolysaccharide inulin, an essential oil mix (carvacrol, thymol), chestnut meal (tannins) and cellulose powder as carrier substance, was examined for effects on growth and faecal and intestinal microflora of piglets. Two experiments (35 days) were conducted, each with 40 male castrated weaned piglets. In experiment 1, graded levels of the PFA were supplied (A1: control; B1: 0.05% PFA; C1: 0.1% PFA; D1: 0.15% PFA) in diets based on wheat, barley, soybean meal and fish meal with lysine as the limiting amino acid. In experiment 2, a similar diet with 0.1% of the PFA (A2: control; B2: 0.1% PFA; C2: +0.35% lysine; D2: 0.1% PFA + 0.35% lysine) and lysine supplementation was utilized. During experiment 1, no significant effect of the PFA on growth, feed intake and feed conversion rate was observed (p > 0.05). Lysine supplementation in experiment 2 improved growth performance significantly, but no significant effect of the PFA was detected. Microbial counts in faeces (aerobes, Gram negatives, anaerobes and lactobacilli) during the first and fifth week did not indicate any significant PFA effect (p > 0.05). In addition, microflora in intestinal samples was not significantly modified by supplementing the PFA (p > 0.05). Lysine supplementation indicated lysine as limiting amino acid in the basal diet, but did not influence the microbial counts in faeces and small intestine respectively.

  6. Predictors of victim disclosure in child sexual abuse: Additional evidence from a sample of incarcerated adult sex offenders.

    PubMed

    Leclerc, Benoit; Wortley, Richard

    2015-05-01

    The under-reporting of child sexual abuse by victims is a serious problem that may prolong the suffering of victims and leave perpetrators free to continue offending. Yet empirical evidence indicates that victim disclosure rates are low. In this study, we perform regression analysis with a sample of 369 adult child sexual offenders to examine potential predictors of victim disclosure. Specifically, we extend the range of previously examined potential predictors of victim disclosure and investigate interaction effects in order to better capture under which circumstances victim disclosure is more likely. The current study differs from previous studies in that it examines the impact of victim and offense variables on victim disclosure from the perspective of the offender. In line with previous studies, we found that disclosure increased with the age of the victim and if penetration had occurred. In addition, we found that disclosure increased when the victim came from a non-dysfunctional family and resisted the abuse. The presence of an interaction effect highlighted the impact of the situation on victim disclosure. This effect indicated that as victims get older, they are more likely to disclose the abuse when they are not living with the offender at the time of abuse, but less likely to do so when they are living with the offender at the time of abuse. These findings are discussed in relation to previous studies and the need to facilitate victim disclosure.

  7. ION COMPOSITION ELUCIDATION (ICE): A HIGH RESOLUTION MASS SPECTROMETRIC TOOL FOR IDENTIFYING ORGANIC COMPOUNDS IN COMPLEX EXTRACTS OF ENVIRONMENTAL SAMPLES

    EPA Science Inventory


    Unidentified Organic Compounds. For target analytes, standards are purchased, extraction and clean-up procedures are optimized, and mass spectra and retention times for the chromatographic separation are obtained for comparison to the target compounds in environmental sample ...

  8. Combining the quick, easy, cheap, effective, rugged and safe approach and clean-up by immunoaffinity column for the analysis of 15 mycotoxins by isotope dilution liquid chromatography tandem mass spectrometry.

    PubMed

    Desmarchelier, Aurélien; Tessiot, Sabine; Bessaire, Thomas; Racault, Lucie; Fiorese, Elisa; Urbani, Alessandro; Chan, Wai-Chinn; Cheng, Pearly; Mottier, Pascal

    2014-04-11

    Optimization and validation of a multi-mycotoxin method by LC-MS/MS is presented. The method covers the EU-regulated mycotoxins (aflatoxins, fumonisins, ochratoxin A, deoxynivalenol, zearalenone, T-2 and HT-2), as well as nivalenol and 3- and 15-acetyldeoxynivalenol for analysis of cereals, cocoa, oil, spices, infant formula, coffee and nuts. The proposed procedure combines two clean-up strategies: First, a generic preparation suitable for all mycotoxins based on the QuEChERS (for quick, easy, cheap, effective, rugged and safe) protocol. Second, a specific clean-up devoted to aflatoxins and ochratoxin A using immunoaffinity column (IAC) clean-up. Positive identification of mycotoxins in matrix was conducted according to the confirmation criteria defined in EU Commission Decision 2002/657/EC while quantification was performed by isotopic dilution using (13)C-labeled mycotoxins as internal standards. Limits of quantification were at or below the maximum levels set in the EC/1886/2006 document for all mycotoxin/matrix combinations under regulation. In particular, the inclusion of an IAC step allowed achieving LOQs as low as 0.05 and 0.25μg/kg in cereals for aflatoxins and ochratoxin A, respectively. Other performance parameters like linearity [(r)(2)>0.99], recovery [71-118%], precision [(RSDr and RSDiR)<33%], and trueness [78-117%] were all compliant with the analytical requirements stipulated in the CEN/TR/16059 document. Method ruggedness was proved by a verification process conducted by another laboratory. PMID:24636559

  9. Combining the quick, easy, cheap, effective, rugged and safe approach and clean-up by immunoaffinity column for the analysis of 15 mycotoxins by isotope dilution liquid chromatography tandem mass spectrometry.

    PubMed

    Desmarchelier, Aurélien; Tessiot, Sabine; Bessaire, Thomas; Racault, Lucie; Fiorese, Elisa; Urbani, Alessandro; Chan, Wai-Chinn; Cheng, Pearly; Mottier, Pascal

    2014-04-11

    Optimization and validation of a multi-mycotoxin method by LC-MS/MS is presented. The method covers the EU-regulated mycotoxins (aflatoxins, fumonisins, ochratoxin A, deoxynivalenol, zearalenone, T-2 and HT-2), as well as nivalenol and 3- and 15-acetyldeoxynivalenol for analysis of cereals, cocoa, oil, spices, infant formula, coffee and nuts. The proposed procedure combines two clean-up strategies: First, a generic preparation suitable for all mycotoxins based on the QuEChERS (for quick, easy, cheap, effective, rugged and safe) protocol. Second, a specific clean-up devoted to aflatoxins and ochratoxin A using immunoaffinity column (IAC) clean-up. Positive identification of mycotoxins in matrix was conducted according to the confirmation criteria defined in EU Commission Decision 2002/657/EC while quantification was performed by isotopic dilution using (13)C-labeled mycotoxins as internal standards. Limits of quantification were at or below the maximum levels set in the EC/1886/2006 document for all mycotoxin/matrix combinations under regulation. In particular, the inclusion of an IAC step allowed achieving LOQs as low as 0.05 and 0.25μg/kg in cereals for aflatoxins and ochratoxin A, respectively. Other performance parameters like linearity [(r)(2)>0.99], recovery [71-118%], precision [(RSDr and RSDiR)<33%], and trueness [78-117%] were all compliant with the analytical requirements stipulated in the CEN/TR/16059 document. Method ruggedness was proved by a verification process conducted by another laboratory.

  10. Solid sampling determination of lithium and sodium additives in microsamples of yttrium oxyorthosilicate by high-resolution continuum source graphite furnace atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Laczai, Nikoletta; Kovács, László; Péter, Ágnes; Bencs, László

    2016-03-01

    Solid sampling high resolution continuum source graphite furnace atomic absorption spectrometry (SS-HR-CS-GFAAS) methods were developed and studied for the fast and sensitive quantitation of Li and Na additives in microsamples of cerium-doped yttrium oxyorthosilicate (Y2SiO5:Ce) scintillator materials. The methods were optimized for solid samples by studying a set of GFAAS conditions (i.e., the sample mass, sensitivity of the analytical lines, and graphite furnace heating programs). Powdered samples in the mass range of 0.099-0.422 mg were dispensed onto graphite sample insertion boats, weighed and analyzed. Pyrolysis and atomization temperatures were optimized by the use of single-element standard solutions of Li and Na (acidified with 0.144 mol/L HNO3) at the Li I 610.353 nm and Na I 285.3013 nm analytical lines. For calibration purposes, the method of standard addition with Li and Na solutions was applied. The correlation coefficients (R values) of the calibration graphs were not worse than 0.9678. The limit of detection for oxyorthosilicate samples was 20 μg/g and 80 μg/g for Li and Na, respectively. The alkaline content of the solid samples were found to be in the range of 0.89 and 8.4 mg/g, respectively. The accuracy of the results was verified by means of analyzing certified reference samples, using methods of standard (solution) addition calibration.

  11. Additional Human Papillomavirus Types Detected by the Hybrid Capture Tube Test among Samples from Women with Cytological and Colposcopical Atypia

    PubMed Central

    Kónya, József; Veress, György; Juhász, Attila; Szarka, Krisztina; Sápy, Tamás; Hernádi, Zoltán; Gergely, Lajos

    2000-01-01

    The type specificity of the human papillomavirus (HPV) Hybrid Capture Tube (HCT) test was evaluated by using typing with PCR (MY09-MY11)-restriction fragment length polymorphism (RFLP) and sequencing. All samples HCT test positive for only low-risk HPV (n = 15) or only high-risk HPV (n = 102) were confirmed, whereas 9 of 12 HCT test double-positive samples contained only high-risk HPV types as determined by PCR-RFLP. Several high-risk HPV types (HPV-53, -58, -62, -66, -CP8304, and -MM4) not included in the HCT test were indeed detected, indicating a broader detection range with retained distinction between low-risk and high-risk HPV types. PMID:10618127

  12. Electrofishing and the effects of depletion sampling on fish health: A review and recommendations for additional study

    USGS Publications Warehouse

    Panek, F.M.; Densmore, Christine L.; Cipriano, R.C.; Bruckner, A.W.; Shchelkunov, I.S.

    2011-01-01

    Depletion sampling in combination with multiple-pass electrofishing is an important fisheries management tool for wadeable streams. This combination of techniques has been used routinely by federal and state fishery management agencies for several decades as a reliable means to obtain quantitative data on trout populations or to describe fish community structure. In this paper we review the effects of electrofishing on fish and discuss this within the context of depletion sampling and multiple exposures of fishes to electric fields. The multiple wave forms most commonly used in sampling (alternating current, direct current, and pulsed direct current) are discussed as well as electrofishing induced response, injury and physiological stress. Fish that survive electrofishing injuries are more likely to suffer short and long-term adverse effects to their behavior, health, growth, or reproduction. Of greatest concern are the native, non-target species that may be subjected to multiple electrical shocks during the course of a 3-pass depletion survey. These exposures and their effects on the non-target species warrant further study as do the overall effects of electrofishing on populations and community structure. 

  13. Determination of organic additives in mortars by near-IR spectroscopy. A novel approach to designing a sample set with high-variability components.

    PubMed

    Blanco, Marcelo; Peguero, Anna

    2007-02-01

    Industrial mortars consist primarily of a mixture of cement and an aggregate plus a small amount of additives that are used to modify specific properties. Using too high or too low additive rates usually results in the loss of desirable properties in the end product. This entails carefully controlling the amounts of additives added to mortar in order to ensure correct dosing and/or adequate homogeneity in the final mixture. Near-IR (NIR) spectroscopy has proved effective for this purpose as it requires no sample pretreatment and affords expeditious analyses. The purpose of this work was to determine two organic additives (viz. Ad1 and Ad2) in mortars by using partial least squares regression multivariate calibration models constructed from NIR spectroscopic data. The additives are used to expedite setting and increase cohesion between particles in the mortar. In order to ensure that the sample set contained natural variability in the samples, we used a methodology based on experimental design to construct a representative set of samples. This novel design is based on a hexagonal antiprism that encompasses the concentration ranges spanned by the analytes and the variability inherent in each additive. The D-optimality criterion was used to obtain various combinations between Ad1 and Ad2 additive classes. The partial least squares calibration models thus constructed for each additive provided accurate predictions: the intercept and the slope of the plots of predicted values versus reference values for each additive were close to 0 and 1, respectively, and their confidence ranges included the respective value. The ensuing analytical methods were validated by using an external sample set.

  14. Evaluation of alternative sorbents for dispersive solid-phase extraction clean-up in the QuEChERS method for the determination of pesticide residues in rice by liquid chromatography with tandem mass spectrometry.

    PubMed

    Cabrera, Liziara da C; Caldas, Sergiane S; Prestes, Osmar D; Primel, Ednei G; Zanella, Renato

    2016-05-01

    Many compounds are used for pest control during the production and storage of rice, making it necessary to employ multiclass methods for pesticide residues determination. For this purpose, QuEChERS-based methods are very efficient, fast and accurate, and improvements in the clean-up step are important, especially for complex matrices, like cereals. In this work, different sorbents such as chitosan, florisil(®) , alumina, diatomaceous earth, graphitized carbon black, besides the commonly used primary secondary amine and octadecylsilane, were evaluated for dispersive solid-phase extraction clean-up in acetate-buffered QuEChERS method for the determination of residues of 20 representative pesticides and one metabolite in rice by liquid chromatography coupled to tandem mass spectrometry. The sorbent C18 presented the best results, however, chitosan showed similar results, and the best performance among the unconventional sorbents evaluated. The method limit of quantification, attending accuracy (70-120% recovery) and precision (RSD ≤20%) criteria, ranged from 5 to 20 μg/kg. Results showed that chitosan is an effective alternative to reduce analysis costs, maintaining the method reliability and accuracy.

  15. Determination of benazolin-ethyl residues in soil and rape seed by SPE clean-up and GC with electron capture detection.

    PubMed

    Liu, Xiaolu; Yang, Tao; Hu, Jiye

    2013-01-01

    A method has been developed and established for residue determination of benazolin-ethyl in soil and rape seed samples by gas chromatography with electron capture detection (GC-ECD). Limits of quantification of the method are 0.005 mg/kg for both soil and rape seed, which are sufficiently below the maximum residue limit, and the limit of detection is 0.0023 ng. The average recoveries of the analyte range from 85.89 to 105.84% with relative standard deviations (coefficient of variation) less than 5.53% at the three spike levels (0.005, 0.1 and 0.5 mg/kg). The half-life of benazolin-ethyl in soil from the experimental field is 4.62 days. The final residues of benazolin-ethyl in soil and rape seed samples are lower than 0.005 mg/kg at harvest time. Direct confirmation of the analyte in real samples is achieved by GC-mass spectrometry. It is demonstrated that the proposed method is simple, rapid and efficient, and reliable to detect benazolin-ethyl residues in soil and rape seed samples.

  16. Determination of benazolin-ethyl residues in soil and rape seed by SPE clean-up and GC with electron capture detection.

    PubMed

    Liu, Xiaolu; Yang, Tao; Hu, Jiye

    2013-01-01

    A method has been developed and established for residue determination of benazolin-ethyl in soil and rape seed samples by gas chromatography with electron capture detection (GC-ECD). Limits of quantification of the method are 0.005 mg/kg for both soil and rape seed, which are sufficiently below the maximum residue limit, and the limit of detection is 0.0023 ng. The average recoveries of the analyte range from 85.89 to 105.84% with relative standard deviations (coefficient of variation) less than 5.53% at the three spike levels (0.005, 0.1 and 0.5 mg/kg). The half-life of benazolin-ethyl in soil from the experimental field is 4.62 days. The final residues of benazolin-ethyl in soil and rape seed samples are lower than 0.005 mg/kg at harvest time. Direct confirmation of the analyte in real samples is achieved by GC-mass spectrometry. It is demonstrated that the proposed method is simple, rapid and efficient, and reliable to detect benazolin-ethyl residues in soil and rape seed samples. PMID:22718745

  17. Can Women Bat Clean-Up, or Must They Simply Do the Cleaning? A Look at Women as Organizational Team Players.

    ERIC Educational Resources Information Center

    Gips, Crystal J.; And Others

    This study focused on the concept of "team player" among women in managerial positions in colleges and universities, and among their immediate supervisors. Female managers defined "team player" in fairly consistent terms. The male superiors tended to agree with the women's definitions but also extended the definitions with the addition of stronger…

  18. Simultaneous determination of 30 hormones illegally added to anti-ageing functional foods using UPLC-MS/MS coupled with SPE clean-up.

    PubMed

    He, Xiaoqin; Xi, Cunxian; Tang, Bobin; Wang, Guomin; Chen, Dongdong; Peng, Tao; Mu, Zhaode

    2014-01-01

    A novel analytical method employing solid-phase extraction (SPE) coupled with ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the simultaneous determination of 30 hormones in anti-ageing functional foods (capsules, powders and tablets). The analytes were extracted with acetic acid-acetonitrile (1-99 v/v), methanol and acetone, respectively. The extract was purified using a combined column, followed by analyte detection with electrospray ionisation in positive- or negative-ion modes. The results indicated that the 30 compounds had good linear correlations in the range of 1-1000 μg kg⁻¹, and the correlation coefficients were above 0.99. The limits of detection (LOD) and limits of quantification (LOQ) were 0.03-2 and 0.1-5 μg kg⁻¹, respectively. The average recovery of 30 compounds at the three spiked levels varied from 74.7% to 124.1%, and the relative standard deviation (RSD) was 2.4-15.0%. This method was applied to the analysis of hormones in 14 real samples of which seven hormones (such as estrone, dienestrol) were detected in four samples, but the remainder of the hormones were not detected. The developed method is sensitive, efficient, reliable and applicable to real samples.

  19. Modelling uncertainty estimation for the determination of aflatoxin M(1) in milk by visual and densitometric thin-layer chromatography with immunoaffinity column clean-up.

    PubMed

    Carvalho, K L; Gonçalves, G A A; Lopes, A L; Santos, E A; Vargas, E A; Magalhães, W F

    2012-01-01

    The uncertainty of aflatoxin M(1) concentration in milk, determined by thin-layer chromatography (TLC) with visual and densitometric quantification of the fluorescence intensities of the spots, was estimated using the cause-and-effect approach proposed by ISO GUM (Guide to the expression of uncertainty in measurement) following its main four steps. The sources of uncertainties due to volume measurements, visual and densitometric TLC calibration curve, allowed range for recovery variation and intermediary precision to be taken into account in the uncertainty budget. For volume measurements the sources of uncertainties due to calibration, resolution, laboratory temperature variation and repeatability were considered. For the quantification by visual readings of the intensity of the aflatoxin M(1) in the TLC the uncertainty arising from resolution calibration curves was modelled based on the intervals of concentrations between pairs of the calibration standard solutions. The uncertainty of the densitometric TLC quantification arising from the calibration curve was obtained by weighted least square (WLS) regression. Finally, the repeatability uncertainty of the densitometric peak areas or of the visual readings for the test sample solutions was considered. For the test samples with aflatoxin M(1) concentration between 0.02 and 0.5 µg l(-1), the relative expanded uncertainties, with approximately 95% of coverage probability, obtained for visual TLC readings were between 60% and 130% of the values predicted by the Horwitz model. For the densitometric TLC determination they were about 20% lower. The main sources of uncertainties in both visual and densitometric TLC quantification were the intermediary precision, calibration curve and recovery. The main source of uncertainty in the calibration curve in the visual TLC analysis was due to the resolution of the visual readings, whereas in the densitometric analysis it was due to the peak areas of test sample solutions

  20. Simultaneous determination of 14 oil-soluble synthetic dyes in chilli products by high performance liquid chromatography with a gel permeation chromatography clean-up procedure.

    PubMed

    Zhu, Yonghong; Zhao, Bo; Xiao, Ruiqi; Yun, Wen; Xiao, Zhaojing; Tu, Dawei; Chen, Shiqi

    2014-02-15

    A method was developed for the simultaneous determination of 14 fat-soluble dyes in chilli products. The samples were extracted with hexane/acetone. The cleanup was performed with gel permeation chromatography (GPC) cleanup system. A HPLC separation was performed using variable wavelength detector and a gradient elution with 0.1% formic acid and methanol-acetonitrile (1:1, v/v) as the mobile phases. Good linearity (R² ≥ 0.995) was observed between 0.1 and 5.0 μg/mL. Detection limits of the investigated dyes, which were evaluated at signal to noise ratio of 3, were in the ranges of 11-71 μg/kg. The recoveries of the 14 synthetic colourants in three matrices ranged from 73.4% to 103.5%. Relative standard deviations ranged from 3.7% to 12.3%. The method has been successfully used for the determination of banned dyes in real samples.

  1. Percent recoveries of anthropogenic organic compounds with and without the addition of ascorbic acid to preserve finished-water samples containing free chlorine, 2004-10

    USGS Publications Warehouse

    Valder, Joshua F.; Delzer, Gregory C.; Bender, David A.; Price, Curtis V.

    2011-01-01

    This report presents finished-water matrix-spike recoveries of 270 anthropogenic organic compounds with and without the addition of ascorbic acid to preserve water samples containing free chlorine. Percent recoveries were calculated using analytical results from a study conducted during 2004-10 for the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS). The study was intended to characterize the effect of quenching on finished-water matrix-spike recoveries and to better understand the potential oxidation and transformation of 270 anthropogenic organic compounds. The anthropogenic organic compounds studied include those on analytical schedules 1433, 2003, 2033, 2060, 2020, and 4024 of the USGS National Water Quality Laboratory. Three types of samples were collected from 34 NAWQA locations across the Nation: (1) quenched finished-water samples (not spiked), (2) quenched finished-water matrix-spike samples, and (3) nonquenched finished-water matrix-spike samples. Percent recoveries of anthropogenic organic compounds in quenched and nonquenched finished-water matrix-spike samples are presented. Comparisons of percent recoveries between quenched and nonquenched spiked samples can be used to show how quenching affects finished-water samples. A maximum of 18 surface-water and 34 groundwater quenched finished-water matrix-spike samples paired with nonquenched finished-water matrix-spike samples were analyzed. Percent recoveries for the study are presented in two ways: (1) finished-water matrix-spike samples supplied by surface-water or groundwater, and (2) by use (or source) group category for surface-water and groundwater supplies. Graphical representations of percent recoveries for the quenched and nonquenched finished-water matrix-spike samples also are presented.

  2. From a Mere Clean-up Contract to Changing Lives - Engaging the Local Stakeholders during the Remediation of Christmas Island, Pacific Ocean

    SciTech Connect

    Steadman, J.P.

    2006-07-01

    This paper describes the work undertaken by Safety and Ecology Corporation Ltd (SEC) on Kiritimati, formerly known as Christmas Island. The discussion describes the project growing from merely removing the remains of the nuclear testing, to appreciating the sensitivities of its economic impact on the island and developing a programme of redevelopment and community involvement. The remediation work has had a number of positive effects on the island, notably upgrading the infrastructure and removing more than 23,000 cubic meters of waste material, primarily metal scrap in the form of vehicles, in addition to spent batteries, extensive areas of tar contaminated soils and radioactive luminous vehicle dials. (authors)

  3. Study Design and Percent Recoveries of Anthropogenic Organic Compounds With and Without the Addition of Ascorbic Acid to Preserve Water Samples Containing Free Chlorine, 2004-06

    USGS Publications Warehouse

    Valder, Joshua F.; Delzer, Gregory C.; Price, Curtis V.; Sandstrom, Mark W.

    2008-01-01

    The National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS) began implementing Source Water-Quality Assessments (SWQAs) in 2002 that focus on characterizing the quality of source water and finished water of aquifers and major rivers used by some of the larger community water systems in the United States. As used for SWQA studies, source water is the raw (ambient) water collected at the supply well prior to water treatment (for ground water) or the raw (ambient) water collected from the river near the intake (for surface water). Finished water is the water that is treated, which typically involves, in part, the addition of chlorine or other disinfection chemicals to remove pathogens, and is ready to be delivered to consumers. Finished water is collected before the water enters the distribution system. This report describes the study design and percent recoveries of anthropogenic organic compounds (AOCs) with and without the addition of ascorbic acid to preserve water samples containing free chlorine. The percent recoveries were determined by using analytical results from a laboratory study conducted in 2004 by the USGS's National Water Quality Laboratory (NWQL) and from data collected during 2004-06 for a field study currently (2008) being conducted by the USGS's NAWQA Program. The laboratory study was designed to determine if preserving samples with ascorbic acid (quenching samples) adversely affects analytical performance under controlled conditions. During the laboratory study, eight samples of reagent water were spiked for each of five analytical schedules evaluated. Percent recoveries from these samples were then compared in two ways: (1) four quenched reagent spiked samples analyzed on day 0 were compared with four quenched reagent spiked samples analyzed on day 7 or 14, and (2) the combined eight quenched reagent spiked samples analyzed on day 0, 7, or 14 were compared with eight laboratory reagent spikes (LRSs). Percent

  4. [Retrospective diagnosis of radiation inhalation lesions of the bronchial mucosa in clean-up personnel after the nuclear accident at the Chernobyl nuclear reactor using the micronucleus test].

    PubMed

    Lisochkin, B G; Kravtsov, V Iu; Rybachenko, V V

    2004-01-01

    The aim of the study was to detect radiation lesions in histological samples of bronchial mucosa in Chernobyl wreckers suffering from chronic non-obstructive bronchitis 10 years after Chernobyl accident by the micronuclear test. The study group consisting of Chernobyl wreckers was comparable to the controls by sex, age, smoking and morphological variants of chronic bronchitis. The test in the study group was positive as it showed a significant increase in the number of the ciliated cells in bronchial mucosa as compared to the control group. This suggests a long-term persistence of the radionuclides in the wreckers' bronchial mucosa. The micronuclear test is recommended for diagnosis of inhalation damage to the lungs in persons exposed to radiation.

  5. Method validation for the analysis of 169 pesticides in soya grain, without clean up, by liquid chromatography-tandem mass spectrometry using positive and negative electrospray ionization.

    PubMed

    Pizzutti, Ionara R; de Kok, André; Zanella, Renato; Adaime, Martha B; Hiemstra, Maurice; Wickert, Cristine; Prestes, Osmar D

    2007-02-23

    Part of a comprehensive study on the comparison of different extraction methods, GC-MS(/MS) and LC-MS/MS detection methods and modes, for the analysis of soya samples is described in this paper. The validation of an acetone-based extraction method for analysis of 169 pesticides in soya, using LC-MS/MS positive and negative electrospray ionisation (ESI) mode, is reported. Samples (5 g) were soaked with 10 g water and subsequently extracted with 100 mL of a mixture of acetone, dichloromethane and light petroleum (1:1:1), in the presence of 15 g anhydrous sodium sulphate. After centrifugation, aliquots of the extract were evaporated and reconstituted in 1.0 mL of methanol, before direct injection of the final extract (corresponding with 0.05 g soya mL(-1)) into the LC-MS/MS system. Linearity, r(2) of calibration curves, instrument limit of detection/quantitation (LOD/LOQ) and matrix effect were evaluated, based on seven concentrations measured in 6-fold. Good linearity (at least r(2)> or =0.99) of the calibration curves was obtained over the range from 0.1 or 0.25 to 10.0 ng mL(-1), corresponding with pesticide concentrations in soya bean extract of 2 or 5-200 microg kg(-1). Instrument LOD values generally were 0.1 or 0.25 ng mL(-1). Matrix effects were negligible for approximately 90% of the pesticides. The accuracy, precision and method LOQ were determined via recovery experiments, spiking soya at 10, 50, 100 microg kg(-1), six replicates per level. In both ESI modes, method LOQ values were mostly 10 or 50 microg kg(-1) and more than 70% of pesticides analysed by each mode met the acceptability criteria of recovery (70-120%) and RSD (< or =20%), at one or more of the three levels studied. A fast, easy and efficient method with acceptable performance was achieved for a difficult matrix as soya, without cleanup.

  6. Selective clean-up applicable to aqueous acetone extracts for the determination of carbendazim and thiabendazole in fruits and vegetables by high-performance liquid chromatography with UV detection.

    PubMed

    Di Muccio, A; Girolimetti, S; Attard Barbini, D; Pelosi, P; Generali, T; Vergori, L; De Merulis, G; Leonelli, A; Stefanelli, P

    1999-02-12

    Fungicide residues in vegetables (benomyl, carbendazim, thiabendazole) are analyzed through a clean-up procedure that uses a portion of the aqueous acetone extract prepared for multiresidue methodology. A portion of the aqueous acetone extract (equivalent to 5 g of vegetables) is loaded onto an Extrelut-20 cartridge (the cartridge is filled with a coarse, large-pore diatomaceous material). Then, acetone is partially removed by an upward stream of nitrogen at 2l/min for 30 min. Benzimidazolic fungicides are recovered by percolating the cartridge with 100 ml of 0.1 M phosphoric acid solution, which also serves to convert benomyl to carbendazim. The percolating acid solution is drained on-line through a strong cation-exchange (SCX) solid-phase extraction cartridge with the aid of a slight vacuum. Benzimidazolic fungicides are retained on the SCX cartridge. The phosphoric acid solution is discarded together with the washings of the SCX cartridge, i.e., water followed by methanol-water (75:25), that remove unwanted coextractives. Finally, benzimidazolic fungicides are recovered by eluting the SCX cartridge with methanol-ammonium formate buffer (75:25). The final extract is then analyzed by reversed-phase HPLC with UV detection. Recoveries from crops such as apples, lettuce, strawberries and citrus fruits are generally greater than 80% and no interferences were observed. The clean-up is simple and straightforward, requires only disposable items, water solutions and a few milliliters of solvent and a minimum number of manipulations, and does not require concentration steps or electrical equipment. PMID:10074700

  7. NCW 2002: Chemistry Keeps Us Clean. Chemists Clean Up: A History and Exploration of the Craft of Soapmaking How Soap Came to be Common in America

    NASA Astrophysics Data System (ADS)

    Kostka, Kim; McKay, David D.

    2002-10-01

    Soap is an article whose commonplace presence and obvious necessity we take for granted at the dawn of the twenty-first century. For most of American history bath soap, however, was a luxury product. This paper explores the confluence of the cultural and technological changes that led to its transformation into the ubiquitous and well-used object it is today. We pick up the timeline for the development of soap in the early American republic when soapmaking was a householder's task and soap use was generally limited to laundering clothes. We then trace the rise of the American cleanliness movement and correlate this rise to the increased manufacturing capabilities of the nation's large soapmakers. This technological forward movement included improvements in producing alkalis as well as the inception and growth of the oleochemicals industry. Additional growth agents were the development of market analysis, advertising campaigns, and factory-scale hydrolysis of fatty acids from their parent fats.

    See Featured Molecules.

  8. The role of methanol addition to water samples in reducing analyte adsorption and matrix effects in liquid chromatography-tandem mass spectrometry.

    PubMed

    Li, Wei; Liu, Yucan; Duan, Jinming; Saint, Christopher P; Mulcahy, Dennis

    2015-04-10

    Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis coupled simply with water filtering before injection has proven to be a simple, economic and time-saving method for analyzing trace-level organic pollutants in aqueous environments. However, the linearity, precision and detection limits of such methods for late-eluting analytes were found to be much poorer than for early-eluting ones due to adsorption of the analytes in the operating system, such as sample vial, flow path and sample loop, creating problems in quantitative analysis. Addition of methanol (MeOH) into water samples as a modifier was shown to be effective in alleviating or even eliminating the negative effect on signal intensity for the late-eluting analytes and at the same time being able to reduce certain matrix effects for real water samples. Based on the maximum detection signal intensity obtained on desorption of the analytes with MeOH addition, the ratio of the detection signal intensity without addition of MeOH to the maximum intensity can be used to evaluate the effectiveness of methanol addition. Accordingly, the values of <50%, 50-80%, 80-120% could be used to indicate strong, medium and no effects, respectively. Based on this concept, an external matrix-matched calibration method with the addition of MeOH has been successfully established for analyzing fifteen pesticides with diverse physico-chemical properties in surface and groundwater with good linearity (r(2): 0.9929-0.9996), precision (intra-day relative standard deviation (RSD): 1.4-10.7%, inter-day RSD: 1.5-9.4%), accuracy (76.9-126.7%) and low limits of detection (0.003-0.028μg/L).

  9. Application of State and Federal Guidelines for Establishing Alternate Soil Clean-Up Levels for the Protection of Groundwater at the Hanford Site

    SciTech Connect

    Leary, K.; McMahon, W.; Hoover, J.

    2008-07-01

    Risk-based soil cleanup levels that are protective of groundwater have been calculated for use in environmental remediation activities at the Hanford Site using vadose zone fate and transport modeling. The determination of soil cleanup levels is important because it involves the technical basis for the levels of contamination that can be left in place, which are protective of human health and the environment. The determination of risk-based soil cleanup levels is an especially important issue at the Hanford Site where site conditions such as a semi-arid climate, and a thick vadose zone of over 100 meters necessitate the use of appropriate risk-based methods. In the absence of an alternative risk-based approach, the cleanup levels default to background, detection limits, or simplistic formulas not intended for applications involving these distinctive site conditions. However, the use of vadose zone fate and transport modeling for risk-based applications such as the determination of soil cleanup levels in the vadose zone are not as well established as modeling for groundwater applications. Thus, the use of models in this manner involves additional challenges for the demonstration of the efficacy of its use for risk-based applications, in accordance with federal and state regulatory requirements and guidelines. An approach has been developed to integrate with federal and state regulatory guidelines in conjunction with the development of the risk-based methodology. Demonstration of integration with these guidelines primarily involves documentation of the objectives of the problem to be solved, the technical basis and rationale associated with the selection of an appropriate risk-based method (e.g., model type and code selection), and documentation associated with the use of the model, e.g., conceptual site model, parameter estimation, uncertainty and assumptions analyses, and model results. (authors)

  10. Cleaning up the Streets of Denver

    SciTech Connect

    Stegen, R.L.; Wood, T.R.; Hackett, J.R.; Sogue, A.

    2006-07-01

    Between 1913 and 1924, several Denver area facilities extracted radium from carnotite ore mined from the Paradox basin region of Colorado. Tailings or abandoned ores from these facilities were apparently incorporated into asphalt used to pave approximately 7.2 kilometers (4.5 miles) of streets in Denver. A majority of the streets are located in residential areas. The radionuclides are bound within the asphalt matrix and pose minimal risk unless they are disturbed. The City and County of Denver (CCoD) is responsible for controlling repairs and maintenance on these impacted streets. Since 2002, the CCoD has embarked on a significant capital improvement project to remove the impacted asphalt for secure disposal followed by street reconstruction. To date, Parsons has removed approximately 55 percent of the impacted asphalt. This paper discusses the history of the Denver Radium Streets and summarizes on-going project efforts. (authors)

  11. Cleaning up the customer satisfaction waste dump

    SciTech Connect

    Plunkett, C.; Katz, G.M.

    1994-11-01

    Most electric utilities have been measuring Customer Satisfaction for several years now with the explicit goal of inducing their employees to improve their handling of customers. While many companies experienced early improvements, the scores have now leveled off. Increasingly, utilities are finding that their Customer Satisfaction Measurement system has reverted to little more than a {open_quotes}report card,{close_quotes} with no clear connection to business practice or processes. Even more alarming is the fact that many companies are now questioning the value of this complicated and expensive effort. This phenomenon is not unique to the electric utility industry -- it is happening in almost every industry in America. What companies really need is a way to tie customer satisfaction to business practices. To accomplish this, the Southern Company, along with several other utilities, are using the Voice of the Customer Process, which came out of the Japanese auto industry. It combines Customer Satisfaction Measurement with Quality Function Deployment (QFD) in order to guide the company into linking specific customer wants and needs to explicit performance measures and business process improvement efforts.

  12. Cleaning up: Battling Germs in School Facilities

    ERIC Educational Resources Information Center

    Gerba, Charles P.

    2009-01-01

    Every school year, parents, teachers, and administrators must deal with an overwhelming number of sick children. In fact, according to the Centers for Disease Control and Prevention, the average child catches at least eight colds a year, and kids in the United States miss as many as 189 million school days annually due to colds. Good hygiene…

  13. Progress and challenges in cleaning up Hanford

    SciTech Connect

    Wagoner, J.D.

    1997-08-01

    This paper presents captioned viewgraphs which briefly summarize cleanup efforts at the Hanford Site. Underground waste tank and spent nuclear fuel issues are described. Progress is reported for the Plutonium Finishing Plant, PUREX plant, B-Plant/Waste Encapsulation Storage Facility, and Fast Flux Test Facility. A very brief overview of costs and number of sites remediated and/or decommissioned is given.

  14. Clean Up Your School Custodial Program.

    ERIC Educational Resources Information Center

    Steller, Arthur W.; Pell, Carroll

    1986-01-01

    Administrators can improve their school's custodial program by following steps that increase productivity, reduce costs, and provide long-term benefits of higher cleanliness standards. Administrators should work toward improved building cleanliness by insisting on a school board policy that establishes objectives for the custodial department.…

  15. Research on Cleaning Up in San Diego.

    ERIC Educational Resources Information Center

    Middleman, Stanley

    1983-01-01

    Discusses the evolution of a set of research programs (dealing with the removal of liquid contaminants from surfaces) used to introduce graduate students to methods of design, evaluation, and modification within the context of a larger research program. Stresses the simultaneity and interaction of theoretical and experimental studies. (JM)

  16. Tanker industry progressing in cleaning up operations

    SciTech Connect

    Knott, D.

    1993-10-18

    The international tanker industry has made significant strides in improving the safety and environmental awareness of its operations in recent years. With a string of mishaps following the Exxon Valdez spill, public scrutiny focused on the tanker industry and found it lacking. The U.S. government reacted strongly with the Oil Pollution Act of 1990. OPA 90 set narrow requirements for tanker construction, forced the creation of a national spill response program, and made tanker operators solely liable for spill damage. The Aegean Sea and Braer accidents around the end of last year forced the pace of European legislation. Since then global initiatives have been announced to improve design and maintenance of tankers and take steps toward eliminating substandard ships and operators. The paper discusses priorities, tanker design, the tanker fleet, OPA status, spill response, the Tampa Bay spill, spill liability, European spills, EC legislation, and the Department of Transportation inquiry.

  17. MHD can clean up the environment

    SciTech Connect

    Sheth, A.C.; Crawford, L.W.; Holt, J.K.

    1993-01-01

    Magnetohydrodynamics (MHD) involves interactions among electromagnetic fields and electrically conducting gases and liquids. The most developed application for MM in the United States is for central station electric power generation using a coal-fired combined cycle system. Proof-of-Concept (POC) scale demonstration of the downstream components used in this technology is currently being carried out at the US Department of Energy's (DOE) Coal-Fired Flow Facility (CFFF), located at the University of Tennessee Space Institute (UTSI). Some of the attractive features of MHD include: A potential for increasing overall plant efficiency to 60% as compared to <40% for conventional power plants. Provision of built-in controls to eliminate/reduce the emissions of acid rain precursors, such as SO[sub 2] and NO[sub x] well below the existing New Source Performance Standards (NSPS) and Clean Air Act requirements. Provision of adequate particulate resistivity for easy and efficient capture of submicron sized panicles in dry and wet electrostatic precipitators. Provision of built-in control to eliminate/reduce the Cl[sub 2]/HCl emission problems common to waste incinerators. Producing nearly zero emissions of priority pollutants (inorganics as well as organics on a pound per pound of coal basis) in comparison to conventional coal-fired facilities. Environmentally acceptable solid and liquid waste streams, and release of less CO[sub 2] (a suspected greenhouse gas) per unit of electricity generated than the conventional power plant due to the increased efficiency.

  18. Synchrotron-based FTIR microspectroscopy for the mapping of photo-oxidation and additives in acrylonitrile-butadiene-styrene model samples and historical objects.

    PubMed

    Saviello, Daniela; Pouyet, Emeline; Toniolo, Lucia; Cotte, Marine; Nevin, Austin

    2014-09-16

    Synchrotron-based Fourier transform infrared micro-spectroscopy (SR-μFTIR) was used to map photo-oxidative degradation of acrylonitrile-butadiene-styrene (ABS) and to investigate the presence and the migration of additives in historical samples from important Italian design objects. High resolution (3×3 μm(2)) molecular maps were obtained by FTIR microspectroscopy in transmission mode, using a new method for the preparation of polymer thin sections. The depth of photo-oxidation in samples was evaluated and accompanied by the formation of ketones, aldehydes, esters, and unsaturated carbonyl compounds. This study demonstrates selective surface oxidation and a probable passivation of material against further degradation. In polymer fragments from design objects made of ABS from the 1960s, UV-stabilizers were detected and mapped, and microscopic inclusions of proteinaceous material were identified and mapped for the first time.

  19. Determination of carbamates in edible vegetable oils by ultra-high performance liquid chromatography-tandem mass spectrometry using a new clean-up based on zirconia for QuEChERS methodology.

    PubMed

    Moreno-González, David; Huertas-Pérez, José F; García-Campaña, Ana M; Gámiz-Gracia, Laura

    2014-10-01

    In this study a fast, selective and sensitive multiresidue method based on QuEChERS methodology has been evaluated and validated for the determination of carbamate pesticides, in edible vegetable oils by UHPLC-MS/MS. A new clean-up sorbent, Supel(TM) QuE Z-Sep(+), has been successfully applied in vegetable oil extracts. Z-Sep(+) was compared with other sorbents (i.e. mixture of C18 and PSA) previously used for dispersive solid phase extraction of these matrices, reducing more effectively matrix effects without a significant decrease of analyte recoveries. Matrix effect was studied in different matrices (extra-virgin olive, sunflower, maize, linseed and sesame oil) being ≤│30│% for most of the studied pesticides. Under optimum conditions, recoveries ranged from 74% to 101%, with relative standard deviations lower than 10%. Limits of quantification ranged from 0.09 to 2.0 µg kg(-1), allowing their determination at the low concentration levels demanding by current legislation.

  20. Determination of carbamates in edible vegetable oils by ultra-high performance liquid chromatography-tandem mass spectrometry using a new clean-up based on zirconia for QuEChERS methodology.

    PubMed

    Moreno-González, David; Huertas-Pérez, José F; García-Campaña, Ana M; Gámiz-Gracia, Laura

    2014-10-01

    In this study a fast, selective and sensitive multiresidue method based on QuEChERS methodology has been evaluated and validated for the determination of carbamate pesticides, in edible vegetable oils by UHPLC-MS/MS. A new clean-up sorbent, Supel(TM) QuE Z-Sep(+), has been successfully applied in vegetable oil extracts. Z-Sep(+) was compared with other sorbents (i.e. mixture of C18 and PSA) previously used for dispersive solid phase extraction of these matrices, reducing more effectively matrix effects without a significant decrease of analyte recoveries. Matrix effect was studied in different matrices (extra-virgin olive, sunflower, maize, linseed and sesame oil) being ≤│30│% for most of the studied pesticides. Under optimum conditions, recoveries ranged from 74% to 101%, with relative standard deviations lower than 10%. Limits of quantification ranged from 0.09 to 2.0 µg kg(-1), allowing their determination at the low concentration levels demanding by current legislation. PMID:25059164

  1. Additional evidence for morpho-dimensional tooth crown variation in a New Indonesian H. erectus sample from the Sangiran Dome (Central Java).

    PubMed

    Zanolli, Clément

    2013-01-01

    This contribution reports fifteen human fossil dental remains found during the last two decades in the Sangiran Dome area, in Central Java, Indonesia. Among this sample, only one of the specimens had already been briefly described, with the other fourteen remaining unreported. Seven of the fifteen isolated teeth were found in a secured stratigraphic context in the late Lower-early Middle Pleistocene Kabuh Formation. The remaining elements were surface finds which, based on coincidental sources of information, were inferred as coming from the Kabuh Formation. Mainly constituted of permanent molars, but also including one upper incisor and one upper premolar, this dental sample brings additional evidence for a marked degree of size variation and time-related structural reduction in Javanese H. erectus. This is notably expressed by a significant decrease of the mesiodistal diameter, frequently associated to the reduction or even loss of the lower molar distal cusp (hypoconulid) and to a more square occlusal outline. In addition to the hypoconulid reduction or loss, this new sample also exhibits a low frequency of the occlusal Y-groove pattern, with a dominance of the X and, to a lesser extent, of the+patterns. This combination is rare in the Lower and early Middle Pleistocene paleoanthropological record, including in the early Javanese dental assemblage from the Sangiran Dome. On the other hand, similar dental features are found in Chinese H. erectus and in H. heidelbergensis. As a whole, this new record confirms the complex nature of the intermittent exchanges that occurred between continental and insular Southeast Asia through the Pleistocene. PMID:23843996

  2. Additional Evidence for Morpho-Dimensional Tooth Crown Variation in a New Indonesian H. erectus Sample from the Sangiran Dome (Central Java)

    PubMed Central

    Zanolli, Clément

    2013-01-01

    This contribution reports fifteen human fossil dental remains found during the last two decades in the Sangiran Dome area, in Central Java, Indonesia. Among this sample, only one of the specimens had already been briefly described, with the other fourteen remaining unreported. Seven of the fifteen isolated teeth were found in a secured stratigraphic context in the late Lower-early Middle Pleistocene Kabuh Formation. The remaining elements were surface finds which, based on coincidental sources of information, were inferred as coming from the Kabuh Formation. Mainly constituted of permanent molars, but also including one upper incisor and one upper premolar, this dental sample brings additional evidence for a marked degree of size variation and time-related structural reduction in Javanese H. erectus. This is notably expressed by a significant decrease of the mesiodistal diameter, frequently associated to the reduction or even loss of the lower molar distal cusp (hypoconulid) and to a more square occlusal outline. In addition to the hypoconulid reduction or loss, this new sample also exhibits a low frequency of the occlusal Y-groove pattern, with a dominance of the X and, to a lesser extent, of the+patterns. This combination is rare in the Lower and early Middle Pleistocene paleoanthropological record, including in the early Javanese dental assemblage from the Sangiran Dome. On the other hand, similar dental features are found in Chinese H. erectus and in H. heidelbergensis. As a whole, this new record confirms the complex nature of the intermittent exchanges that occurred between continental and insular Southeast Asia through the Pleistocene. PMID:23843996

  3. Effect of surfactant addition on ultrasonic leaching of trace elements from plant samples in inductively coupled plasma-atomic emission spectrometry

    NASA Astrophysics Data System (ADS)

    Borkowska-Burnecka, Jolanta; Jankowiak, Urszula; Zyrnicki, Wieslaw; Anna Wilk, Kazimiera

    2004-04-01

    The applicability of surfactants in sample preparation of plant materials followed by analysis by inductively coupled plasma atomic emission spectrometry has been examined. Reference materials (INCT-MPH-2-Mixed Polish Herbs, INCT-TL-1 black tea leaves and CTA-VTL-2 -Virginia tobacco leaves) and commercially available tea leaves were analyzed. Effects of addition surfactants (Triton X-100, didodecyldimethylammonium bromide and cetyltrimethylammonium bromide) on efficiency of ultrasonic leaching of elements from the plant samples and on plasma parameters were investigated. Low concentrations of the surfactants in solutions did not affect, in practice, analytical line intensities and the nebulization process. Quantitative recovery of some elements could be obtained by ultrasonic diluted acid leaching with the aid of surfactants. However, the element recovery depended on type of surfactant, as well as element and sample material. Plasma parameters, i.e. the excitation temperatures of Ar I, Fe II and Ca II as well as the electron number density and the Mg II/Mg I intensity ratio did not vary significantly due to the surfactants in solutions.

  4. Effect of additional sample bias in Meshed Plasma Immersion Ion Deposition (MPIID) on microstructural, surface and mechanical properties of Si-DLC films

    NASA Astrophysics Data System (ADS)

    Wu, Mingzhong; Tian, Xiubo; Li, Muqin; Gong, Chunzhi; Wei, Ronghua

    2016-07-01

    Meshed Plasma Immersion Ion Deposition (MPIID) using cage-like hollow cathode discharge is a modified process of conventional PIID, but it allows the deposition of thick diamond-like carbon (DLC) films (up to 50 μm) at a high deposition rate (up to 6.5 μm/h). To further improve the DLC film properties, a new approach to the MPIID process is proposed, in which the energy of ions incident to the sample surface can be independently controlled by an additional voltage applied between the samples and the metal meshed cage. In this study, the meshed cage was biased with a pulsed DC power supply at -1350 V peak voltage for the plasma generation, while the samples inside the cage were biased with a DC voltage from 0 V to -500 V with respect to the cage to study its effect. Si-DLC films were synthesized with a mixture of Ar, C2H2 and tetramethylsilane (TMS). After the depositions, scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectrons spectroscopy (XPS), Raman spectroscopy and nanoindentation were used to study the morphology, surface roughness, chemical bonding and structure, and the surface hardness as well as the modulus of elasticity of the Si-DLC films. It was observed that the intense ion bombardment significantly densified the films, reduced the surface roughness, reduced the H and Si contents, and increased the nanohardness (H) and modulus of elasticity (E), whereas the deposition rate decreased slightly. Using the H and E data, high values of H3/E2 and H/E were obtained on the biased films, indicating the potential excellent mechanical and tribological properties of the films. In this paper, the effects of the sample bias voltage on the film properties are discussed in detail and the optimal bias voltage is presented.

  5. Analytical techniques for the detection and identification of chemical warfare materials from environmental samples

    SciTech Connect

    Beaudry, W.T.; Weimaster, J.F.

    1995-06-01

    The detection and identification of chemical warfare (CW) material in diverse and complex matrices has become increasingly important to support the environmental clean-up of military and industrial sites that were historically used in the research, production, use, storage and/or demilitarization of chemical weapons. Reliable and defensible identification of hazardous materials (HM) is necessary to comply with the increasingly stringent regulations imposed by local, state, and federal agencies which govern handling, treatment, storage, and disposal of HM. In addition, before sites can be reutilized, existing HM must be properly identified so that the proper methods of removal, treatment and disposal can be determined. An overview of sample preparation and analytical techniques for the detection and identification of CW materials is presented in this paper.

  6. State of the art of environmentally friendly sample preparation approaches for determination of PBDEs and metabolites in environmental and biological samples: A critical review.

    PubMed

    Berton, Paula; Lana, Nerina B; Ríos, Juan M; García-Reyes, Juan F; Altamirano, Jorgelina C

    2016-01-28

    Green chemistry principles for developing methodologies have gained attention in analytical chemistry in recent decades. A growing number of analytical techniques have been proposed for determination of organic persistent pollutants in environmental and biological samples. In this light, the current review aims to present state-of-the-art sample preparation approaches based on green analytical principles proposed for the determination of polybrominated diphenyl ethers (PBDEs) and metabolites (OH-PBDEs and MeO-PBDEs) in environmental and biological samples. Approaches to lower the solvent consumption and accelerate the extraction, such as pressurized liquid extraction, microwave-assisted extraction, and ultrasound-assisted extraction, are discussed in this review. Special attention is paid to miniaturized sample preparation methodologies and strategies proposed to reduce organic solvent consumption. Additionally, extraction techniques based on alternative solvents (surfactants, supercritical fluids, or ionic liquids) are also commented in this work, even though these are scarcely used for determination of PBDEs. In addition to liquid-based extraction techniques, solid-based analytical techniques are also addressed. The development of greener, faster and simpler sample preparation approaches has increased in recent years (2003-2013). Among green extraction techniques, those based on the liquid phase predominate over those based on the solid phase (71% vs. 29%, respectively). For solid samples, solvent assisted extraction techniques are preferred for leaching of PBDEs, and liquid phase microextraction techniques are mostly used for liquid samples. Likewise, green characteristics of the instrumental analysis used after the extraction and clean-up steps are briefly discussed.

  7. Impact of 2'-hydroxyl sampling on the conformational properties of RNA: update of the CHARMM all-atom additive force field for RNA.

    PubMed

    Denning, Elizabeth J; Priyakumar, U Deva; Nilsson, Lennart; Mackerell, Alexander D

    2011-07-15

    Here, we present an update of the CHARMM27 all-atom additive force field for nucleic acids that improves the treatment of RNA molecules. The original CHARMM27 force field parameters exhibit enhanced Watson-Crick base pair opening which is not consistent with experiment, whereas analysis of molecular dynamics (MD) simulations show the 2'-hydroxyl moiety to almost exclusively sample the O3' orientation. Quantum mechanical (QM) studies of RNA related model compounds indicate the energy minimum associated with the O3' orientation to be too favorable, consistent with the MD results. Optimization of the dihedral parameters dictating the energy of the 2'-hydroxyl proton targeting the QM data yielded several parameter sets, which sample both the base and O3' orientations of the 2'-hydroxyl to varying degrees. Selection of the final dihedral parameters was based on reproduction of hydration behavior as related to a survey of crystallographic data and better agreement with experimental NMR J-coupling values. Application of the model, designated CHARMM36, to a collection of canonical and noncanonical RNA molecules reveals overall improved agreement with a range of experimental observables as compared to CHARMM27. The results also indicate the sensitivity of the conformational heterogeneity of RNA to the orientation of the 2'-hydroxyl moiety and support a model whereby the 2'-hydroxyl can enhance the probability of conformational transitions in RNA.

  8. Use of ion-molecule reactions and methanol addition to improve arsenic determination in high chlorine food samples by DRC-ICP-MS.

    PubMed

    Guo, Wei; Hu, Shenghong; Li, Xiaofang; Zhao, Jian; Jin, Shesheng; Liu, Wenjuan; Zhang, Hongfei

    2011-05-15

    Direct determination of trace arsenic in high chlorine food samples by ICP-MS is complicated by the presence of ArCl(+) interferences, and the high first ionization energy of As (9.81 eV) also results in low analytical sensitivity in ICP-MS. In this work, two strategies based on ion-molecule reactions were successfully used to eliminate ArCl spectral interference in a dynamic reaction cell (DRC). The interference ion ((40)Ar(35)Cl(+)) was directly removed by the reaction with methane gas, and the background signal was reduced by up to 100-fold at m/z 75. Alternatively, by using molecule oxygen as the reaction gas, (75)As(+) was effectively converted to (75)As(16)O(+) that could be detected at m/z 91 where the background is low. The poor signal intensity of As or AsO was improved 3-4 times by addition of 4% methanol in the analyzed solutions. The limit of quantitation (LOQ) for (75)As (CH(4)-DRC method) and (75)As(16)O (O(2)-DRC method) was 0.8 and 0.3 ng g(-1) and the analytical results of seaweed and yellow croaker standard reference materials were in good agreement with the certified values. As the routine arsenic monitoring method in our laboratory, it was applied to the accuracy determination of 119 high chlorine food samples from eight different markets of Beijing.

  9. Deriving site-specific clean-up criteria to protect ecological receptors (plants and soil invertebrates) exposed to metal or metalloid soil contaminants via the direct contact exposure pathway.

    PubMed

    Checkai, Ron; Van Genderen, Eric; Sousa, José Paulo; Stephenson, Gladys; Smolders, Erik

    2014-07-01

    Soil contaminant concentration limits for the protection of terrestrial plants and soil invertebrates are commonly based on thresholds derived using data from laboratory ecotoxicity tests. A comprehensive assessment has been made for the derivation of ecological soil screening levels (Eco-SSL) in the United States; however, these limits are conservative because of their focus on high bioavailability scenarios. Here, we explain and evaluate approaches to soil limit derivation taken by 4 jurisdictions, 2 of which allow for correction of data for factors affecting bioavailability among soils, and between spiked and field-contaminated soils (Registration Evaluation Authorisation and Restriction of Chemicals [REACH] Regulation, European Union [EU], and the National Environment Protection Council [NEPC], Australia). Scientifically advanced features from these methods have been integrated into a newly developed method for deriving soil clean-up values (SCVs) within the context of site-specific baseline ecological risk assessment. Resulting site-specific SCVs that account for bioavailability may permit a greater residual concentration in soil when compared to generic screening limit concentrations (e.g., Eco-SSL), while still affording acceptable protection. Two choices for selecting the level of protection are compared (i.e., allowing higher effect levels per species, or allowing a higher percentile of species that are potentially unprotected). Implementation of this new method is presented for the jurisdiction of the United States, with a focus on metal and metalloid contaminants; however, the new method can be used in any jurisdiction. A case study for molybdate shows the large effect of bioavailability corrections and smaller effects of protection level choices when deriving SCVs.

  10. Improved method for the simultaneous determination of aflatoxins, ochratoxin A and Fusarium toxins in cereals and derived products by liquid chromatography-tandem mass spectrometry after multi-toxin immunoaffinity clean up.

    PubMed

    Lattanzio, Veronica Maria Teresa; Ciasca, Biancamaria; Powers, Stephen; Visconti, Angelo

    2014-08-01

    An improved method for the quantitative determination of aflatoxins (B1, B2, G1, G2), ochratoxin A, fumonisins (B1, B2), zearalenone, deoxynivalenol, nivalenol, T-2 and HT-2 toxins in cereals and derived products, at levels comparable with EU maximum permitted levels, was developed. The effective co-extraction of the mycotoxins under investigation was achieved in 4min by a double extraction approach, using water followed by methanol. Clean up of the extract was performed by a new multi-toxin immunoaffinity column. Analytical performance characteristics were evaluated through single laboratory validation. Raw wheat and maize, corn flakes and maize snacks were chosen as representative matrices for method validation. The validation assay was carried out at 50, 100 and 150% of EU maximum permitted levels for each mycotoxin. Statistical analysis of the results (ANOVA) provided the within laboratory reproducibility and the error contributions from repeatability, between day effects, and influences from different matrix composition. Recoveries generally higher than 70% were obtained for all tested mycotoxins with relative standard deviation (within laboratory reproducibility) lesser than 37%. Limits of quantification (calculated as the lowest amount of each analyte which could be determined with a precision of 10%) ranged from 1μg/kg to 30μg/kg. The trueness of generated data was assessed by analysis of reference materials. The proposed method was proven to be suitable to assess, with a single analysis, compliance of the selected cereal based foods with the EU maximum permitted or recommended levels for all regulated mycotoxins.

  11. Deriving site-specific clean-up criteria to protect ecological receptors (plants and soil invertebrates) exposed to metal or metalloid soil contaminants via the direct contact exposure pathway

    PubMed Central

    Checkai, Ron; Van Genderen, Eric; Sousa, José Paulo; Stephenson, Gladys; Smolders, Erik

    2014-01-01

    Soil contaminant concentration limits for the protection of terrestrial plants and soil invertebrates are commonly based on thresholds derived using data from laboratory ecotoxicity tests. A comprehensive assessment has been made for the derivation of ecological soil screening levels (Eco-SSL) in the United States; however, these limits are conservative because of their focus on high bioavailability scenarios. Here, we explain and evaluate approaches to soil limit derivation taken by 4 jurisdictions, 2 of which allow for correction of data for factors affecting bioavailability among soils, and between spiked and field-contaminated soils (Registration Evaluation Authorisation and Restriction of Chemicals [REACH] Regulation, European Union [EU], and the National Environment Protection Council [NEPC], Australia). Scientifically advanced features from these methods have been integrated into a newly developed method for deriving soil clean-up values (SCVs) within the context of site-specific baseline ecological risk assessment. Resulting site-specific SCVs that account for bioavailability may permit a greater residual concentration in soil when compared to generic screening limit concentrations (e.g., Eco-SSL), while still affording acceptable protection. Two choices for selecting the level of protection are compared (i.e., allowing higher effect levels per species, or allowing a higher percentile of species that are potentially unprotected). Implementation of this new method is presented for the jurisdiction of the United States, with a focus on metal and metalloid contaminants; however, the new method can be used in any jurisdiction. A case study for molybdate shows the large effect of bioavailability corrections and smaller effects of protection level choices when deriving SCVs. Integr Environ Assess Manag 2014;10:346–357. PMID:24470189

  12. Analysis of sequences from field samples reveals the presence of the recently described pepper vein yellows virus (genus Polerovirus) in six additional countries.

    PubMed

    Knierim, Dennis; Tsai, Wen-Shi; Kenyon, Lawrence

    2013-06-01

    Polerovirus infection was detected by reverse transcription polymerase chain reaction (RT-PCR) in 29 pepper plants (Capsicum spp.) and one black nightshade plant (Solanum nigrum) sample collected from fields in India, Indonesia, Mali, Philippines, Thailand and Taiwan. At least two representative samples for each country were selected to generate a general polerovirus RT-PCR product of 1.4 kb length for sequencing. Sequence analysis of the partial genome sequences revealed the presence of pepper vein yellows virus (PeVYV) in all 13 samples. A 1990 Australian herbarium sample of pepper described by serological means as infected with capsicum yellows virus (CYV) was identified by sequence analysis of a partial CP sequence as probably infected with a potato leaf roll virus (PLRV) isolate.

  13. FT-Raman and chemometric tools for rapid determination of quality parameters in milk powder: Classification of samples for the presence of lactose and fraud detection by addition of maltodextrin.

    PubMed

    Rodrigues Júnior, Paulo Henrique; de Sá Oliveira, Kamila; de Almeida, Carlos Eduardo Rocha; De Oliveira, Luiz Fernando Cappa; Stephani, Rodrigo; Pinto, Michele da Silva; de Carvalho, Antônio Fernandes; Perrone, Ítalo Tuler

    2016-04-01

    FT-Raman spectroscopy has been explored as a quick screening method to evaluate the presence of lactose and identify milk powder samples adulterated with maltodextrin (2.5-50% w/w). Raman measurements can easily differentiate samples of milk powder, without the need for sample preparation, while traditional quality control methods, including high performance liquid chromatography, are cumbersome and slow. FT-Raman spectra were obtained from samples of whole lactose and low-lactose milk powder, both without and with addition of maltodextrin. Differences were observed between the spectra involved in identifying samples with low lactose content, as well as adulterated samples. Exploratory data analysis using Raman spectroscopy and multivariate analysis was also developed to classify samples with PCA and PLS-DA. The PLS-DA models obtained allowed to correctly classify all samples. These results demonstrate the utility of FT-Raman spectroscopy in combination with chemometrics to infer about the quality of milk powder.

  14. Maps showing mines, quarries, oil and gas activity, and sample localities in and near the Sipsey Wilderness and additions, Lawrence and Winston Counties, Alabama

    SciTech Connect

    Mory, P.C.; Behum, P.T.; Ross, R.B. Jr.

    1982-01-01

    This report presents the results of a mineral survey of the Sipsey Wilderness and additions, William B. Bankhead National Forest, Lawrence and Winston Counties, Alabama. The survey includes: limestone quarrying, coal mining, and oil and gas activity. 7 references, 5 figures, 2 tables.

  15. Capillary electrophoretic separation of humic substances using hydroxyethyl cellulose as a buffer additive and its application to characterization of humic substances in a river water sample.

    PubMed

    Takahashi, Toru; Kawana, Jun; Hoshino, Hitoshi

    2009-01-01

    We have developed a concise tool for the investigation of the transition of humic substances in environmental water. The separation of water-soluble humic substances was achieved rapidly and effectively by capillary electrophoresis using a polyacrylamide-coated capillary and a phosphate electrophoretic buffer solution (pH 7.0) containing hydroxyethyl cellulose. The separation mechanism was assessed using the ultrafiltration technique. The effect of the complexation of humic substances with metal ions was studied by using the proposed method. When Fe(III) ions or EDTA was added to the sample solution of fulvic acid, a distinct change in the electropherogram pattern based on the conformational change of fulvic acid was observed. The successful application of the proposed method to the characterization of humic substances in a river water sample was also demonstrated.

  16. Determination of benzophenones in human placental tissue samples by liquid chromatography-tandem mass spectrometry.

    PubMed

    Vela-Soria, F; Jiménez-Díaz, I; Rodríguez-Gómez, R; Zafra-Gómez, A; Ballesteros, O; Navalón, A; Vílchez, J L; Fernández, M F; Olea, N

    2011-09-30

    Benzophenones (BPs) are a family of compounds widely used to protect the skin and hair from UV irradiation. Despite human exposure to BPs through dermal application of products containing sunscreen agents and the increasing evidence that BPs are able to interfere with endocrine systems, few studies have examined the occurrence of BPs in humans. In this work, we propose a new liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to determine six BPs, namely, benzophenone-1 (BP-1), benzophenone-2 (BP-2), benzophenone-3 (BP-3), benzophenone-6 (BP-6), benzophenone-8 (BP-8) and 4-hydroxybenzophenone (4-OH-BP) in human placental tissue samples. The method involves an extraction step of the analytes from the samples using ethyl acetate, followed by a clean-up step using centrifugation prior to their quantification by LC-MS/MS using an atmospheric pressure chemical ionization (APCI) interface in the positive mode. Benzophenone-d(10) (BP-d(10)) was used as surrogate. Found detection limits (LOD) ranged from 0.07 to 0.3 ng g(-1) and quantification limits (LOQ) from 0.3 to 1.0 ng g(-1), while inter- and intra-day variability was under 5%. The method was validated using standard addition calibration and a recovery assay. Recovery rates for spiked samples ranged from 98 to 104%. This method was satisfactorily applied for the determination of BPs in 16 placental tissue samples collected from women who live in Granada (Spain).

  17. State of the art of environmentally friendly sample preparation approaches for determination of PBDEs and metabolites in environmental and biological samples: A critical review.

    PubMed

    Berton, Paula; Lana, Nerina B; Ríos, Juan M; García-Reyes, Juan F; Altamirano, Jorgelina C

    2016-01-28

    Green chemistry principles for developing methodologies have gained attention in analytical chemistry in recent decades. A growing number of analytical techniques have been proposed for determination of organic persistent pollutants in environmental and biological samples. In this light, the current review aims to present state-of-the-art sample preparation approaches based on green analytical principles proposed for the determination of polybrominated diphenyl ethers (PBDEs) and metabolites (OH-PBDEs and MeO-PBDEs) in environmental and biological samples. Approaches to lower the solvent consumption and accelerate the extraction, such as pressurized liquid extraction, microwave-assisted extraction, and ultrasound-assisted extraction, are discussed in this review. Special attention is paid to miniaturized sample preparation methodologies and strategies proposed to reduce organic solvent consumption. Additionally, extraction techniques based on alternative solvents (surfactants, supercritical fluids, or ionic liquids) are also commented in this work, even though these are scarcely used for determination of PBDEs. In addition to liquid-based extraction techniques, solid-based analytical techniques are also addressed. The development of greener, faster and simpler sample preparation approaches has increased in recent years (2003-2013). Among green extraction techniques, those based on the liquid phase predominate over those based on the solid phase (71% vs. 29%, respectively). For solid samples, solvent assisted extraction techniques are preferred for leaching of PBDEs, and liquid phase microextraction techniques are mostly used for liquid samples. Likewise, green characteristics of the instrumental analysis used after the extraction and clean-up steps are briefly discussed. PMID:26755134

  18. Food additives

    PubMed Central

    Spencer, Michael

    1974-01-01

    Food additives are discussed from the food technology point of view. The reasons for their use are summarized: (1) to protect food from chemical and microbiological attack; (2) to even out seasonal supplies; (3) to improve their eating quality; (4) to improve their nutritional value. The various types of food additives are considered, e.g. colours, flavours, emulsifiers, bread and flour additives, preservatives, and nutritional additives. The paper concludes with consideration of those circumstances in which the use of additives is (a) justified and (b) unjustified. PMID:4467857

  19. Characterisation of vitamin B12 immunoaffinity columns and method development for determination of vitamin B12 in a range of foods, juices and pharmaceutical products using immunoaffinity clean-up and high performance liquid chromatography with UV detection.

    PubMed

    Marley, E C; Mackay, E; Young, G

    2009-03-01

    New rapid and simpler procedures, using immunoaffinity columns, have been developed for the determination of vitamin B12 in a range of samples including three different US National Institute of Standard and Technology (NIST) Reference Materials, infant formula, powdered energy drinks and bars, wheat breakfast cereal, carbonated soft drinks, fruit juices and vitamin B12 tablets. The procedures involved extraction of vitamin B12 using water or sodium acetate buffer and enzyme digestion (using pepsin or alpha-amylase, or both) if necessary. The extract was clarified and passed through "EASI-EXTRACT Vitamin B12", an immunoaffinity column containing monoclonal antibody with high affinity and specificity to vitamin B12. Subsequently, the vitamin B12 immunoaffinity column was washed with 10 ml water and the vitamin B12 was released from the column with 3 ml methanol. Following evaporation, the samples were reconstituted in mobile phase and analysed by HPLC-UV at 361 nm on an ACE 3AQ analytical column using a gradient elution consisting of 0.025% trifluoroacetic acid in water and acetonitrile. Analysis of three types of NIST Standard Reference Materials in triplicate demonstrated the results of the immunoaffinity column method were comparable to microbiological assay results. Method repeatability was determined for all samples analysed and ranged between 0.8 and 10%, demonstrating the method was repeatable with complex matrices (NIST 2383) containing low levels of vitamin B12 (0.44 microg per 100 g), as well as simpler matrices, such as vitamin tablets containing high levels (2000 microg per 0.849 g) of vitamin B12. PMID:19680900

  20. Review of sample preparation strategies for MS-based metabolomic studies in industrial biotechnology.

    PubMed

    Causon, Tim J; Hann, Stephan

    2016-09-28

    Fermentation and cell culture biotechnology in the form of so-called "cell factories" now play an increasingly significant role in production of both large (e.g. proteins, biopharmaceuticals) and small organic molecules for a wide variety of applications. However, associated metabolic engineering optimisation processes relying on genetic modification of organisms used in cell factories, or alteration of production conditions remain a challenging undertaking for improving the final yield and quality of cell factory products. In addition to genomic, transcriptomic and proteomic workflows, analytical metabolomics continues to play a critical role in studying detailed aspects of critical pathways (e.g. via targeted quantification of metabolites), identification of biosynthetic intermediates, and also for phenotype differentiation and the elucidation of previously unknown pathways (e.g. via non-targeted strategies). However, the diversity of primary and secondary metabolites and the broad concentration ranges encompassed during typical biotechnological processes means that simultaneous extraction and robust analytical determination of all parts of interest of the metabolome is effectively impossible. As the integration of metabolome data with transcriptome and proteome data is an essential goal of both targeted and non-targeted methods addressing production optimisation goals, additional sample preparation steps beyond necessary sampling, quenching and extraction protocols including clean-up, analyte enrichment, and derivatisation are important considerations for some classes of metabolites, especially those present in low concentrations or exhibiting poor stability. This contribution critically assesses the potential of current sample preparation strategies applied in metabolomic studies of industrially-relevant cell factory organisms using mass spectrometry-based platforms primarily coupled to liquid-phase sample introduction (i.e. flow injection, liquid

  1. Combining Electrochemical Sensors with Miniaturized Sample Preparation for Rapid Detection in Clinical Samples

    PubMed Central

    Bunyakul, Natinan; Baeumner, Antje J.

    2015-01-01

    Clinical analyses benefit world-wide from rapid and reliable diagnostics tests. New tests are sought with greatest demand not only for new analytes, but also to reduce costs, complexity and lengthy analysis times of current techniques. Among the myriad of possibilities available today to develop new test systems, amperometric biosensors are prominent players—best represented by the ubiquitous amperometric-based glucose sensors. Electrochemical approaches in general require little and often enough only simple hardware components, are rugged and yet provide low limits of detection. They thus offer many of the desirable attributes for point-of-care/point-of-need tests. This review focuses on investigating the important integration of sample preparation with (primarily electrochemical) biosensors. Sample clean up requirements, miniaturized sample preparation strategies, and their potential integration with sensors will be discussed, focusing on clinical sample analyses. PMID:25558994

  2. Combining electrochemical sensors with miniaturized sample preparation for rapid detection in clinical samples.

    PubMed

    Bunyakul, Natinan; Baeumner, Antje J

    2015-01-01

    Clinical analyses benefit world-wide from rapid and reliable diagnostics tests. New tests are sought with greatest demand not only for new analytes, but also to reduce costs, complexity and lengthy analysis times of current techniques. Among the myriad of possibilities available today to develop new test systems, amperometric biosensors are prominent players-best represented by the ubiquitous amperometric-based glucose sensors. Electrochemical approaches in general require little and often enough only simple hardware components, are rugged and yet provide low limits of detection. They thus offer many of the desirable attributes for point-of-care/point-of-need tests. This review focuses on investigating the important integration of sample preparation with (primarily electrochemical) biosensors. Sample clean up requirements, miniaturized sample preparation strategies, and their potential integration with sensors will be discussed, focusing on clinical sample analyses. PMID:25558994

  3. Novel solid phase extraction method for the analysis of 5-nitroimidazoles and metabolites in milk samples by capillary electrophoresis.

    PubMed

    Hernández-Mesa, Maykel; García-Campaña, Ana M; Cruces-Blanco, Carmen

    2014-02-15

    A new sample treatment has been developed for the extraction of 5-nitroimidazole (5-NDZ) drugs in milk samples previous to their determination by micellar electrokinetic chromatography (MEKC). Fat removing and protein precipitation were simultaneously carried out by the addition of trichloroacetic acid (TCA) and subsequent centrifugation. Clean-up and off-line concentration were achieved by a novel solid-phase extraction (SPE) method employing mixed cation exchange (MCX) cartridges, obtaining an off-line concentration factor of 18. Analyses were performed in less than 18 min employing 20mM phosphate buffer (pH 6.5) and 150 mM SDS as background electrolyte (BGE). During the separation procedure a temperature of 20 °C and a voltage of 25 kV (normal mode) were applied. Due to sweeping effects, an on-line concentration was achieved for all the studied compounds and detection limits lower than 1.8 μg L(-1) were obtained. This method has been successfully applied to milk samples of different origins, including raw ewe milk.

  4. Phosphazene additives

    DOEpatents

    Harrup, Mason K; Rollins, Harry W

    2013-11-26

    An additive comprising a phosphazene compound that has at least two reactive functional groups and at least one capping functional group bonded to phosphorus atoms of the phosphazene compound. One of the at least two reactive functional groups is configured to react with cellulose and the other of the at least two reactive functional groups is configured to react with a resin, such as an amine resin of a polycarboxylic acid resin. The at least one capping functional group is selected from the group consisting of a short chain ether group, an alkoxy group, or an aryloxy group. Also disclosed are an additive-resin admixture, a method of treating a wood product, and a wood product.

  5. Potlining Additives

    SciTech Connect

    Rudolf Keller

    2004-08-10

    In this project, a concept to improve the performance of aluminum production cells by introducing potlining additives was examined and tested. Boron oxide was added to cathode blocks, and titanium was dissolved in the metal pool; this resulted in the formation of titanium diboride and caused the molten aluminum to wet the carbonaceous cathode surface. Such wetting reportedly leads to operational improvements and extended cell life. In addition, boron oxide suppresses cyanide formation. This final report presents and discusses the results of this project. Substantial economic benefits for the practical implementation of the technology are projected, especially for modern cells with graphitized blocks. For example, with an energy savings of about 5% and an increase in pot life from 1500 to 2500 days, a cost savings of $ 0.023 per pound of aluminum produced is projected for a 200 kA pot.

  6. RECOMMENDATIONS FOR SAMPLING OF TANK 18 IN F TANK FARM

    SciTech Connect

    Shine, G.

    2009-12-14

    Representative sampling is required for characterization of the residual floor material in Tank 18 prior to operational closure. Tank 18 is an 85-foot diameter, 34-foot high carbon steel tank with nominal operating volume of 1,300,000 gallons. It is a Type IV tank, and has been in service storing radioactive materials since 1959. Recent mechanical cleaning of the tank removed all mounds of material. Anticipating a low level of solids in the residual material, Huff and Thaxton [2009] developed a plan to sample the material during the final clean-up process while it would still be resident in sufficient quantities to support analytical determinations in four quadrants of the tank. Execution of the plan produced fewer solids than expected to support analytical determinations in all four quadrants. Huff and Thaxton [2009] then restructured the plan to characterize the residual floor material separately in the North and the South regions: two 'hemispheres.' This document provides sampling recommendations to complete the characterization of the residual material on the tank bottom following the guidance in Huff and Thaxton [2009] to split the tank floor into a North and a South hemisphere. The number of samples is determined from a modification of the formula previously published in Edwards [2001] and the sample characterization data for previous sampling of Tank 18 described by Oji [2009]. The uncertainty is quantified by an upper 95% confidence limit (UCL95%) on each analyte's mean concentration in Tank 18. The procedure computes the uncertainty in analyte concentration as a function of the number of samples, and the final number of samples is determined when the reduction in the uncertainty from an additional sample no longer has a practical impact on results. The characterization of the full suite of analytes in the North hemisphere is currently supported by a single Mantis rover sample obtained from a compact region near the center riser. A floor scrape sample was

  7. Non-PBDE halogenated flame retardants in Canadian indoor house dust: sampling, analysis, and occurrence.

    PubMed

    Fan, Xinghua; Kubwabo, Cariton; Rasmussen, Pat E; Wu, Fang

    2016-04-01

    An analytical method was developed for the measurement of 18 novel halogenated flame retardants in house dust. Sample preparation was based on ultrasound-assisted solvent extraction and clean up with solid phase extraction (SPE). Sample extracts were analyzed by gas chromatography-mass spectrometry (GC/MS) operated in electron capture negative ion (ECNI) chemical ionization mode. Baseline data from 351 fresh (active) dust samples collected under the Canadian House Dust Study (CHDS) revealed that five out of 18 target chemicals were present with detection frequencies higher than 90 %. Median (range) concentrations for these five compounds were as follows: 104 (<1.5-13,000) ng/g for 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EHTBB), 8.5 (<1.7-2390) ng/g for 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), 10.2 (<1.7-430) ng/g for hexabromobenzene (HBB), 2.9 (<1.2-1410) ng/g for syn-dechlorane plus (syn-DP) and 5.6 (<1.9-1570) ng/g for anti-dechlorane plus (anti-DP). A comparison of two sampling methods in a subset of 40 homes showed significant positive correlations between samples of "active" dust and samples taken directly from the household vacuum cleaner for all target compounds having median values above their corresponding method detection limits (MDLs). In addition, the method was also applied to the analysis of the targeted compounds in National Institute of Standards and Technology (NIST) standard reference material (SRM 2585, organic contaminants in house dust). Results from the current study could contribute to the potential certification of target chemicals in SRM 2585.

  8. Non-PBDE halogenated flame retardants in Canadian indoor house dust: sampling, analysis, and occurrence.

    PubMed

    Fan, Xinghua; Kubwabo, Cariton; Rasmussen, Pat E; Wu, Fang

    2016-04-01

    An analytical method was developed for the measurement of 18 novel halogenated flame retardants in house dust. Sample preparation was based on ultrasound-assisted solvent extraction and clean up with solid phase extraction (SPE). Sample extracts were analyzed by gas chromatography-mass spectrometry (GC/MS) operated in electron capture negative ion (ECNI) chemical ionization mode. Baseline data from 351 fresh (active) dust samples collected under the Canadian House Dust Study (CHDS) revealed that five out of 18 target chemicals were present with detection frequencies higher than 90 %. Median (range) concentrations for these five compounds were as follows: 104 (<1.5-13,000) ng/g for 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EHTBB), 8.5 (<1.7-2390) ng/g for 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), 10.2 (<1.7-430) ng/g for hexabromobenzene (HBB), 2.9 (<1.2-1410) ng/g for syn-dechlorane plus (syn-DP) and 5.6 (<1.9-1570) ng/g for anti-dechlorane plus (anti-DP). A comparison of two sampling methods in a subset of 40 homes showed significant positive correlations between samples of "active" dust and samples taken directly from the household vacuum cleaner for all target compounds having median values above their corresponding method detection limits (MDLs). In addition, the method was also applied to the analysis of the targeted compounds in National Institute of Standards and Technology (NIST) standard reference material (SRM 2585, organic contaminants in house dust). Results from the current study could contribute to the potential certification of target chemicals in SRM 2585. PMID:26780041

  9. Uses of bioremediation for pesticide waste clean-up

    SciTech Connect

    Massey, J.H.; Lavy, T.L.

    1994-12-31

    Bioremediation technologies enhance the growth and activity of microorganisms in order to degrade and/or detoxify chemical wastes. Stricter EPA guidelines concerning chemical contamination of soil and water, and potential cost savings over traditional remediation practices have increased interest in bioremediation. The pesticide and petroleum contamination found at some agrichemical dealerships may lend themselves to bioremediation. In order to assess the applicability of a given bioremediation practice, a basic knowledge of bioremediation is helpful. This paper reviews basic bioremediation concepts and practices.

  10. Training Workers for Environmental Clean-Up Jobs.

    ERIC Educational Resources Information Center

    Baldwin, Fred

    1993-01-01

    Describes the International Union of Operating Engineers (IUOE) Hazmat Training Program (Beckley, WV). It is the largest program in the nation for training skilled workers to safely handle toxic and hazardous wastes. This program has produced more than 450 certified instructors, who, in turn, have trained more than 18,000 workers. (LP)

  11. San Diego perspective on UST clean-ups

    SciTech Connect

    Anderson, J.P.

    1996-12-31

    In June 1994, CalEPA State Water Resources Control Board (State Board) contracted with the Lawrence Livermore National Laboratory/University of California (LLNL/UC) to review the current UST regulatory framework and cleanup process. As a result of their review, LLNL/UC recommended changes to expedite the cleanup process at leaking UST sites. The LLNL/UC report concludes that natural attenuation of petroleum is an important factor in stabilizing plumes and may be the only remedial activity necessary in the absence of the source. After a review of existing literature and a study of selected leaking UST cases primarily from Coastal Range sedimentary or valley alluvium hydrogeochemical provinces, the LLNL/UC report found that petroleum plumes tend to stabilize close to the source, generally occur in shallow groundwater, and rarely impact drinking water wells in the state. The study and report recommendations focused solely on fuel petroleum hydrocarbon constituents.

  12. MSO spent salt clean-up recovery process

    SciTech Connect

    Adamson, M G; Brummond, W A; Hipple, D L; Hsu, P C; Summers, L J; Von Holtz, E H; Wang, F T

    1997-02-01

    An effective process has been developed to separate metals, mineral residues, and radionuclides from spent salt, a secondary waste generated by Molten Salt Oxidation (MSO). This process includes salt dissolution, pH adjustment, chemical reduction and/or sulfiding, filtration, ion exchange, and drying. The process uses dithionite to reduce soluble chromate and/or sulfiding agent to suppress solubilities of metal compounds in water. This process is capable of reducing the secondary waste to less than 5% of its original weight. It is a low temperature, aqueous process and has been demonstrated in the laboratory [1].

  13. Novel Sorbent to Clean Up Biogas for CHPs

    SciTech Connect

    Alptekin, Gökhan O.; Jayataman, Ambalavanan; Schaefer, Matthew; Ware, Michael; Hunt, Jennifer; Dobek, Frank

    2015-05-30

    In this project, TDA Research Inc. (TDA) has developed low-cost (on a per unit volume of gas processed basis), high-capacity expendable sorbents that can remove both the H2S and organic sulfur species in biogas to the ppb levels. The proposed sorbents will operate downstream of a bulk desulfurization system as a polishing bed to provide an essentially sulfur-free gas to a fuel cell (or any other application that needs a completely sulfur-free feed). Our sorbents use a highly dispersed mixed metal oxides active phase with desired modifiers prepared over on a mesoporous support. The support structure allows the large organic sulfur compounds (such as the diethyl sulfide and dipropyl sulfide phases with a large kinetic diameter) to enter the sorbent pores so that they can be adsorbed and removed from the gas stream.

  14. Wet-air oxidation cleans up black wastewater

    SciTech Connect

    Not Available

    1993-09-01

    Sterling Organics produces the analgesic paracetamol (acetaminophen) at its Dudley, England, plant. The wastewater from the batch process contains intermediates such as para-aminophenol (PAP) and byproducts such as thiosulfates, sulfites and sulfides. To stay ahead of increasingly strict environmental legislation, Sterling Organics installed a wet-air oxidation system at the Dudley facility in August 1992. The system is made by Zimpro Environmental Inc. (Rothschild, Wis.). Zimpro's wet-air oxidation system finds a way around the limitations of purely chemical or physical processes. In the process, compressed air at elevated temperature and pressure oxidizes the process intermediates and byproducts and removes the color from the wastewater.

  15. Cleaning up Trumpet Sound: Some Paths to Better Tone

    ERIC Educational Resources Information Center

    Zingara, James J.

    2004-01-01

    Of all the factors used to assess trumpet players, the one that distinguishes the established professional from the student is sound quality. While a good sound may be called "full," "rich," or "dark," poor sound is often described as "constricted," "tight," "thin," or "fuzzy." Although students' concept of good sound is important, many times…

  16. Absorbent agents for clean-up of liquid hydrocarbons

    SciTech Connect

    Waldmann, J.J.

    1993-08-24

    A method is described for absorbing liquid hydrocarbon from a liquid hydrocarbon-contaminated substrate comprising applying to said contaminated substrate an effective amount of a chemical absorbent composition of formula: A[sub m]B[sub n]C[sub p] wherein A[sub m] is an acid leached bentonite in a form of hydrous silicate of alumina modified by a hydrophobic alkyl (C[sub 12]-C[sub 24]) amine which has been double protonized by an aliphatic acid with C[sub 1]-C[sub 18] carbon atoms in which m = 0 to 100% by weight of the composition; B[sub n] is a modified aminoplast resin comprised of cyanoguanidine-melamine-urea-formaldehyde in a foam form in which n is 0 to 100% by weight; and C[sub p] is a siliceous support-modified hydrophobic material in which p is 0 to 100% by weight; provided that at least one of m and n is a positive numerical value.

  17. Beyond symbiosis: cleaner shrimp clean up in culture.

    PubMed

    Militz, Thane A; Hutson, Kate S

    2015-01-01

    Cleaner organisms exhibit a remarkable natural behaviour where they consume ectoparasites attached to "client" organisms. While this behaviour can be utilized as a natural method of parasitic disease control (or biocontrol), it is not known whether cleaner organisms can also limit reinfection from parasite eggs and larvae within the environment. Here we show that cleaner shrimp, Lysmata amboinensis, consume eggs and larvae of a harmful monogenean parasite, Neobenedenia sp., in aquaculture. Shrimp consumed parasite eggs under diurnal (63%) and nocturnal (14%) conditions as well as infectious larvae (oncomiracidia) diurnally (26%). Furthermore, we trialled the inclusion of cleaner shrimp for preventative parasite management of ornamental fish, Pseudanthias squamipinnis, and found shrimp reduced oncomiracidia infection success of host fish by half compared to controls (held without shrimp). Fish held without cleaner shrimp exhibited pigmentation changes as a result of infection, possibly indicative of a stress response. These results provide the first empirical evidence that cleaner organisms reduce parasite loads in the environment through non-symbiotic cleaning activities. Our research findings have relevance to aquaculture and the marine ornamental trade, where cleaner shrimp could be applied for prophylaxis and control of ectoparasite infections. PMID:25706952

  18. Beyond Symbiosis: Cleaner Shrimp Clean Up in Culture

    PubMed Central

    Militz, Thane A.; Hutson, Kate S.

    2015-01-01

    Cleaner organisms exhibit a remarkable natural behaviour where they consume ectoparasites attached to “client” organisms. While this behaviour can be utilized as a natural method of parasitic disease control (or biocontrol), it is not known whether cleaner organisms can also limit reinfection from parasite eggs and larvae within the environment. Here we show that cleaner shrimp, Lysmata amboinensis, consume eggs and larvae of a harmful monogenean parasite, Neobenedenia sp., in aquaculture. Shrimp consumed parasite eggs under diurnal (63%) and nocturnal (14%) conditions as well as infectious larvae (oncomiracidia) diurnally (26%). Furthermore, we trialled the inclusion of cleaner shrimp for preventative parasite management of ornamental fish, Pseudanthias squamipinnis, and found shrimp reduced oncomiracidia infection success of host fish by half compared to controls (held without shrimp). Fish held without cleaner shrimp exhibited pigmentation changes as a result of infection, possibly indicative of a stress response. These results provide the first empirical evidence that cleaner organisms reduce parasite loads in the environment through non-symbiotic cleaning activities. Our research findings have relevance to aquaculture and the marine ornamental trade, where cleaner shrimp could be applied for prophylaxis and control of ectoparasite infections. PMID:25706952

  19. Cleaning up That Mess: A Framework for Classifying Educational Apps

    ERIC Educational Resources Information Center

    Cherner, Todd; Dix , Judy; Lee, Corey

    2014-01-01

    As tablet technologies continue to evolve, the emergence of educational applications (apps) is impacting the work of teacher educators. Beyond online lists of best apps for education and recommendations from colleagues, teacher educators have few resources available to support their teaching of how to select educational apps. In response, this…

  20. Bioenergy residues as novel sorbents to clean up pesticide pollution

    NASA Astrophysics Data System (ADS)

    Mukherjee, Santanu

    2016-04-01

    Worldwide, water contamination from agricultural use of pesticides has received increasing attention within the last decades. In general, sources of pesticide water pollution are categorized into diffuse (stemming from treated fields) and point sources (stemming from farmyards and spillages). Research has demonstrated that 40 to 90% of surface water pesticide contamination is due to point source pollution. To reduce point pollution from farm yards, where the spray equipment is washed, biobed or biofilter systems are used to treat the washing water. The organic material usually used in these systems is often not environmentally sustainable (e.g. peat) and incorporated organic material such as straw leads to a highly heterogeneous water flow, with negative effects on the retention and degradation behavior of the pesticides. Therefore, the objective of this study was to assess the suitability of alternative materials based on bioenergy residues (biochar and digestate) for use in biofilters. To this aim the sorption-desorption potential of three contrasting pesticides (bentazone, boscalid, and pyrimethanil) on mixtures of soil with digestate and/or biochar were investigated in laboratory batch equilibrium experiments. The results indicate that the mixture of digestate and biochar increased pesticide sorption potential, whereby in all cases, the Kd des / Kf des values were lower than the Kd ads / Kf ads values indicating that the retention of the pesticides was weak. Thus, as Kf des were lower than the Kf ads values and H values were below 1, it can be concluded that the biomixtures presented negative desorption (higher hysteresis) in those cases. A higher Kd (>78 L kg-1), Kf (>400 μM1-1/nf L1/nfkg-1) and KL (>40 L kg-1) was obtained for all pesticides for the digestate and biochar based mixtures, which had a higher organic matter content. However, lower sorption of the pesticides was observed in blank soil compared to the other biomixtures, which was attributed to the lower organic carbon content of the blank soil. Our results showed that boscalid and pyrimethanil are highly sorbed to the mixture of digestate and biochar. SUVA254 values justified the aromatic character of digestate (5%) and biochar (5%) mixture which showed highest Koc values among all mixtures for all pesticides. This mixture was found to be the most promising substrate amongst the tested ones for a biobed setup and can be used as an effective and alternative adsorbent for removing pesticides, because of its higher adsorption capacity.

  1. Background clean-up in Brillouin microspectroscopy of scattering medium.

    PubMed

    Meng, Zhaokai; Traverso, Andrew J; Yakovlev, Vladislav V

    2014-03-10

    Brillouin spectroscopy is an emerging tool for microscopic optical imaging as it allows for non-contact, non-invasive, direct assessment of the elastic properties of materials. However, strong elastic scattering and stray light from various sources often contaminate the Brillouin spectrum. A molecular absorption cell was introduced into the virtually imaged phased array (VIPA) based Brillouin spectroscopy setup to absorb the Rayleigh component, which resulted in a substantial improvement of the Brillouin spectrum quality.

  2. Background clean-up in Brillouin microspectroscopy of scattering medium

    PubMed Central

    Meng, Zhaokai; Traverso, Andrew J.; Yakovlev, Vladislav V.

    2014-01-01

    Brillouin spectroscopy is an emerging tool for microscopic optical imaging as it allows for non-contact, non-invasive, direct assessment of the elastic properties of materials. However, strong elastic scattering and stray light from various sources often contaminate the Brillouin spectrum. A molecular absorption cell was introduced into the virtually imaged phased array (VIPA) based Brillouin spectroscopy setup to absorb the Rayleigh component, which resulted in a substantial improvement of the Brillouin spectrum quality. PMID:24663880

  3. News from Online: Cleaning Up--Soap, Detergent, and More.

    ERIC Educational Resources Information Center

    Judd, Carolyn Sweeney

    2002-01-01

    Provides a guide to web resources on cleaning and hygiene. Answers the questions, What do you want to clean--your hair? your carpet? your rusty lawn furniture? Develops special products for different tasks. Focuses on products to use and the environmental impact of our choices. (MM)

  4. 75 FR 62923 - WRC-07 Table Clean-up Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-13

    ...-Federal space stations) to the bottom of the cell in the non-Federal Table in the bands 148-149.9, 400.15... is also allocated to the meteorological-satellite service (space-to-Earth) on a primary basis,...

  5. Cleaning up: Colleges Do Their Part to Revitalize the Gulf

    ERIC Educational Resources Information Center

    Violino, Bob

    2011-01-01

    When the deepwater horizon offshore oil drilling rig exploded in the Gulf of Mexico in April 2010, 11 crewmen were killed; the accident led to the largest oil spill in U.S. history. Forty workers on the rig managed to escape the catastrophe, thanks largely to a safety-training program they had taken at community colleges in the Louisiana Community…

  6. Rehabilitative bodywork: cleaning up the dirty work of homecare.

    PubMed

    Meldgaard Hansen, Agnete

    2016-09-01

    Care work for elderly people has been characterised as dirty work, owing to its proximity to the (dys)functions and discharges of aged bodies and the notions of disease, decay and death associated with the idea of old age. However, a wave of reform programmes in Danish municipalities promoting rehabilitative care practices aiming to empower, train and activate elderly citizens provides opportunities for homecare workers to renegotiate their status and reconstruct their work and occupational identities with a cleaner and more optimistic image. Drawing on ethnographic fieldwork in two Danish homecare units, this article analyses how rehabilitative care practices, drawing on a narrative of the third age, provide an optimistic and anti-ageist framing of homecare work that informs the development of new occupational identities for care workers as coaches rather than carers in relation to citizens. Furthermore, rehabilitation efforts change the bodywork of care, rendering it more distanced and physically passive, and rehabilitation efforts also involve extensive motivational work aiming to help citizens to see themselves as capable, resourceful and self-reliant. However, while rehabilitation efforts become a new resource in care workers' taint management; they also entail potentially negative consequences in terms of responsibilising and disciplinary approaches to elderly citizens. PMID:27132631

  7. Rodent Control: Seal Up! Trap Up! Clean Up!

    MedlinePlus

    ... successfully trapping rodents in and around the home. Seal Up! Seal up holes inside and outside the home to ... infested areas. Before cleaning, trap the rodents and seal up any entryways to ensure that no rodents ...

  8. Cleaning Up the Seas. UNEP Environment Brief No. 5.

    ERIC Educational Resources Information Center

    United Nations Environment Programme, Nairobi (Kenya).

    While the open oceans remain relatively unpolluted, many coastal areas are suffering from oil, sewage, industrial wastes, and agricultural run-off. This document presents some of the key facts related to these kinds of water pollution. It focuses on the major sources of contamination in the world's seas, and provides an overview of how these…

  9. GaAs clean up studied with synchrotron radiation photoemission

    NASA Astrophysics Data System (ADS)

    Tallarida, Massimo; Adelmann, Christoph; Delabie, Annelies; van Elshocht, Sven; Caymax, Matty; Schmeisser, Dieter

    2012-12-01

    In this contribution we describe the chemical changes at the surface of GaAs upon adsorption of tri-methyl-aluminum (TMA). TMA is used to grow Al2O3 with atomic layer deposition (ALD) usually using H2O as oxygen source. Recently, it was pointed out that the adsorption of TMA on various III-V surfaces reduces the native oxide, allowing the growth of an abrupt III-V/High-K interface with reduced density of defects. Synchrotron radiation photoemission spectroscopy (SR-PES) is a powerful method to characterize surfaces and interfaces of many materials, as it is capable to determine their chemical composition as well as the electronic properties. We performed in-situ SR-PES measurements after exposing a GaAs surface to TMA pulses at about 250°C. Upon using the possibility of tuning the incident photon energy we compared the Ga3d spectra at 41 eV, 71 eV, 91 eV and 121 eV, as well as the As3d at 71 eV and 91 eV. Finally, we show that using SR-PES allows a further understanding of the surface composition, which is usually not accessible with other techniques.

  10. DOE and Public Involvement A Key to Successful Clean Up

    SciTech Connect

    Sarten, S.

    2008-07-01

    The combination of two vital elements in the Oak Ridge, TN area are the Department of Energy and the education of the public, at any age, of the necessary work that is and has been going on this region of the country since the setting aside of land during the World War II era. A wide variety of interested citizens from surrounding counties make up a group of individuals that bring different elements of education and involvement to form a committee of whose interest is the Department of Energy's handling of contaminated material. The effort of one of the committees on this board has given the public a resource of material to develop a better understanding of the history and stewardship efforts taking place at the Oak Ridge Reservation. (authors)

  11. Oil spills debris clean up by thermal desorption.

    PubMed

    Araruna, J T; Portes, V L O; Soares, A P L; Silva, M G; Sthel, M S; Schramm, D U; Tibana, S; Vargas, H

    2004-07-01

    Oil spills represent a significant environmental issue in Brazil. This paper presents the latest results of a comprehensive experimental programme aimed at understanding how the presence of spilled oil affects the properties of sands and at studying alternatives to remediate the affected shores. Results indicate that oil causes a slight increase in grain size and uniformity, and oiled debris presents a smaller void ratio but a larger unit weight. It was also observed that effective strength parameters for both the natural and oiled debris were the same although the undrained strength of a natural sand is much higher than that of the contaminated sand. At ambient temperature, oiled debris emits methane and ammonia, and these emissions tend to increase with rising temperatures. On the other hand, the oil and grease content from oiled debris decreases with rising temperature and prolonged exposure. Finally, in situ thermal desorption seems to be a promising method for cleaning debris from oil spills. It is simple, fast and avoids all the difficulties associated with digging up the soil for disposal or cleanup.

  12. Canada's plan for coal: Clean up or shut Down

    SciTech Connect

    2010-10-15

    The plan would affect 21 large coal-fired plants consisting of 51 units currently generating roughly 19 percent of the country's electricity and yielding 13 percent of its GHG emissions. the actual impact of the plan is stretched over a period of time, allowing for alternatives to make up the gap created by the coal shutdown. If all goes according to the plan, Canada's GHG emissions will drop by 17 percent relative to 2005 levels by 2020.

  13. Telescope to clean up echo of Big Bang

    NASA Astrophysics Data System (ADS)

    Catanzaro, Michele

    2008-12-01

    One of a pair of telescopes that will help in the search for signatures of gravitational waves in the cosmic microwave background (CMB) will be inaugurated next month at the Teide Mountain Observatory on the island of Tenerife in Spain. The project, named Quijote and costing €1.5m, will produce a map of photon polarization of the CMB at frequencies of 10-30 GHz. Although it will not directly detect gravitational waves, Quijote will characterize the signals that contaminate CMB measurements. The second, larger telescope will open later next year.

  14. Beyond symbiosis: cleaner shrimp clean up in culture.

    PubMed

    Militz, Thane A; Hutson, Kate S

    2015-01-01

    Cleaner organisms exhibit a remarkable natural behaviour where they consume ectoparasites attached to "client" organisms. While this behaviour can be utilized as a natural method of parasitic disease control (or biocontrol), it is not known whether cleaner organisms can also limit reinfection from parasite eggs and larvae within the environment. Here we show that cleaner shrimp, Lysmata amboinensis, consume eggs and larvae of a harmful monogenean parasite, Neobenedenia sp., in aquaculture. Shrimp consumed parasite eggs under diurnal (63%) and nocturnal (14%) conditions as well as infectious larvae (oncomiracidia) diurnally (26%). Furthermore, we trialled the inclusion of cleaner shrimp for preventative parasite management of ornamental fish, Pseudanthias squamipinnis, and found shrimp reduced oncomiracidia infection success of host fish by half compared to controls (held without shrimp). Fish held without cleaner shrimp exhibited pigmentation changes as a result of infection, possibly indicative of a stress response. These results provide the first empirical evidence that cleaner organisms reduce parasite loads in the environment through non-symbiotic cleaning activities. Our research findings have relevance to aquaculture and the marine ornamental trade, where cleaner shrimp could be applied for prophylaxis and control of ectoparasite infections.

  15. Sources of Technical Variability in Quantitative LC-MS Proteomics: Human Brain Tissue Sample Analysis.

    SciTech Connect

    Piehowski, Paul D.; Petyuk, Vladislav A.; Orton, Daniel J.; Xie, Fang; Moore, Ronald J.; Ramirez Restrepo, Manuel; Engel, Anzhelika; Lieberman, Andrew P.; Albin, Roger L.; Camp, David G.; Smith, Richard D.; Myers, Amanda J.

    2013-05-03

    To design a robust quantitative proteomics study, an understanding of both the inherent heterogeneity of the biological samples being studied as well as the technical variability of the proteomics methods and platform is needed. Additionally, accurately identifying the technical steps associated with the largest variability would provide valuable information for the improvement and design of future processing pipelines. We present an experimental strategy that allows for a detailed examination of the variability of the quantitative LC-MS proteomics measurements. By replicating analyses at different stages of processing, various technical components can be estimated and their individual contribution to technical variability can be dissected. This design can be easily adapted to other quantitative proteomics pipelines. Herein, we applied this methodology to our label-free workflow for the processing of human brain tissue. For this application, the pipeline was divided into four critical components: Tissue dissection and homogenization (extraction), protein denaturation followed by trypsin digestion and SPE clean-up (digestion), short-term run-to-run instrumental response fluctuation (instrumental variance), and long-term drift of the quantitative response of the LC-MS/MS platform over the 2 week period of continuous analysis (instrumental stability). From this analysis, we found the following contributions to variability: extraction (72%) >> instrumental variance (16%) > instrumental stability (8.4%) > digestion (3.1%). Furthermore, the stability of the platform and its’ suitability for discovery proteomics studies is demonstrated.

  16. Risk-based approach to developing a national residue sampling plan for testing under European Union regulation for veterinary medicinal products and coccidiostat feed additives in domestic animal production.

    PubMed

    Danaher, Martin; Shanahan, Conor; Butler, Francis; Evans, Rhodri; O'Sullivan, Dan; Glynn, Denise; Camon, Tim; Lawlor, Peadar; O'Keeffe, Michael

    2016-07-01

    A ranking system for veterinary medicinal products and coccidiostat feed additives has been developed as a tool to be applied in a risk-based approach to the residue testing programme for foods of animal origin in the Irish National Residue Control Plan (NRCP). Three characteristics of substances that may occur as residues in food are included in the developed risk ranking system: Potency, as measured by the acceptable daily intake assigned by the European Medicines Agency Committee for Medicinal Products for Veterinary Use, to each substance; Usage, as measured by the three factors of Number of Doses, use on Individual animals or for Group treatment, and Withdrawal Period; and Residue Occurrence, as measured by the number of Non-Compliant Samples in the NRCP. For both Number of Doses and Non-Compliant Samples, data for the 5-year period 2008-12 have been used. The risk ranking system for substances was developed for beef cattle, sheep and goats, pigs, chickens and dairy cattle using a scoring system applied to the various parameters described above to give an overall score based on the following equation: Potency × Usage (Number of Doses + Individual/Group Use + Withdrawal Period) × Residue Occurrence. Applying this risk ranking system, the following substances are ranked very highly: antimicrobials such as amoxicillin (for all species except pigs), marbofloxacillin (for beef cattle), oxytetracycline (for all species except chickens), sulfadiazine with trimethoprim (for pigs and chickens) and tilmicosin (for chickens); antiparasitic drugs, such as the benzimidazoles triclabendazole (for beef and dairy cattle), fenbendazole/oxfendazole (for sheep/goats and dairy cattle) and albendazole (for dairy cattle), the avermectin ivermectin (for beef cattle), and anti-fluke drugs closantel and rafoxanide (for sheep/goats); the anticoccidials monensin, narasin, nicarbazin and toltrazuril (for chickens). The risk ranking system described is a relatively simple system

  17. Risk-based approach to developing a national residue sampling plan for testing under European Union regulation for veterinary medicinal products and coccidiostat feed additives in domestic animal production.

    PubMed

    Danaher, Martin; Shanahan, Conor; Butler, Francis; Evans, Rhodri; O'Sullivan, Dan; Glynn, Denise; Camon, Tim; Lawlor, Peadar; O'Keeffe, Michael

    2016-07-01

    A ranking system for veterinary medicinal products and coccidiostat feed additives has been developed as a tool to be applied in a risk-based approach to the residue testing programme for foods of animal origin in the Irish National Residue Control Plan (NRCP). Three characteristics of substances that may occur as residues in food are included in the developed risk ranking system: Potency, as measured by the acceptable daily intake assigned by the European Medicines Agency Committee for Medicinal Products for Veterinary Use, to each substance; Usage, as measured by the three factors of Number of Doses, use on Individual animals or for Group treatment, and Withdrawal Period; and Residue Occurrence, as measured by the number of Non-Compliant Samples in the NRCP. For both Number of Doses and Non-Compliant Samples, data for the 5-year period 2008-12 have been used. The risk ranking system for substances was developed for beef cattle, sheep and goats, pigs, chickens and dairy cattle using a scoring system applied to the various parameters described above to give an overall score based on the following equation: Potency × Usage (Number of Doses + Individual/Group Use + Withdrawal Period) × Residue Occurrence. Applying this risk ranking system, the following substances are ranked very highly: antimicrobials such as amoxicillin (for all species except pigs), marbofloxacillin (for beef cattle), oxytetracycline (for all species except chickens), sulfadiazine with trimethoprim (for pigs and chickens) and tilmicosin (for chickens); antiparasitic drugs, such as the benzimidazoles triclabendazole (for beef and dairy cattle), fenbendazole/oxfendazole (for sheep/goats and dairy cattle) and albendazole (for dairy cattle), the avermectin ivermectin (for beef cattle), and anti-fluke drugs closantel and rafoxanide (for sheep/goats); the anticoccidials monensin, narasin, nicarbazin and toltrazuril (for chickens). The risk ranking system described is a relatively simple system

  18. Gas-liquid chromatographic and gas-liquid-mass spectometric determination of fenvalerate and permethrin residues in grasshoppers and duck tissue samples

    USGS Publications Warehouse

    Reichel, W.L.; Kolbe, E.J.; Stafford, C.J.

    1981-01-01

    A procedure is described for determining fenvalerate and permethrin residues in grasshoppers and duck tissues. Samples are Soxhlet-extracted with hexane and cleaned up by gel permeation chromatography with an in-line alumina column. Samples are analyzed by gas-liquid chromatography with electron capture detection, and confirmed by gas-liquid chromatography-mass spectrometry. The average recovery from fortified tissues was 97%.

  19. RECOMMENDATIONS FOR SAMPLING OF TANK 19 IN F TANK FARM

    SciTech Connect

    Harris, S.; Shine, G.

    2009-12-14

    Representative sampling is required for characterization of the residual material in Tank 19 prior to operational closure. Tank 19 is a Type IV underground waste storage tank located in the F-Tank Farm. It is a cylindrical-shaped, carbon steel tank with a diameter of 85 feet, a height of 34.25 feet, and a working capacity of 1.3 million gallons. Tank 19 was placed in service in 1961 and initially received a small amount of low heat waste from Tank 17. It then served as an evaporator concentrate (saltcake) receiver from February 1962 to September 1976. Tank 19 also received the spent zeolite ion exchange media from a cesium removal column that once operated in the Northeast riser of the tank to remove cesium from the evaporator overheads. Recent mechanical cleaning of the tank removed all mounds of material. Anticipating a low level of solids in the residual waste, Huff and Thaxton [2009] developed a plan to sample the waste during the final clean-up process while it would still be resident in sufficient quantities to support analytical determinations in four quadrants of the tank. Execution of the plan produced fewer solids than expected to support analytical determinations in all four quadrants. Huff and Thaxton [2009] then restructured the plan to characterize the residual separately in the North and the South regions: two 'hemispheres.' This document provides sampling recommendations to complete the characterization of the residual material on the tank bottom following the guidance in Huff and Thaxton [2009] to split the tank floor into a North and a South hemisphere. The number of samples is determined from a modification of the formula previously published in Edwards [2001] and the sample characterization data for previous sampling of Tank 19 described by Oji [2009]. The uncertainty is quantified by an upper 95% confidence limit (UCL95%) on each analyte's mean concentration in Tank 19. The procedure computes the uncertainty in analyte concentration as a

  20. Quantitative analysis of bisphosphonates in biological samples.

    PubMed

    Lapko, Veniamin N; Miller, Patrick S; Sheldon, Curtis E; Nachi, Ridha; Kafonek, Chris J

    2014-01-01

    Bisphosphonate drugs pose significant challenges for bioanalysis due to various complicating factors. In 2006, a novel approach, utilizing 'on-column' derivatization with diazomethane, was reported that revolutionized the application of liquid-chromatography-tandem mass spectrometry to bisphosphonates bioanalysis. The methodology enables superior biological sample clean-up while transforming bisphosphonates into species amenable to liquid-chromatography-tandem mass spectrometry detection. Since then, the approach has been successfully applied to numerous bisphosphonates. The use of an alternative methylation reagent - trimethylsilyl diazomethane - for on-column derivatization has been reported recently. This review focuses on published methods utilizing on-column derivatization for bioanalysis of major bisphosphonate drugs in biological matrices. Critical points required for successful application of on-column derivatization to the bioanalysis of bisphosphonates will be discussed.

  1. Optimization for Peptide Sample Preparation for Urine Peptidomics

    SciTech Connect

    Sigdel, Tara K.; Nicora, Carrie D.; Hsieh, Szu-Chuan; Dai, Hong; Qian, Weijun; Camp, David G.; Sarwal, Minnie M.

    2014-02-25

    when utilizing the conventional SPE method. In conclusion, the mSPE method was found to be superior to the conventional, standard SPE method for urine peptide sample preparation when applying LC-MS peptidomics analysis due to the optimized sample clean up that provided improved experimental inference from the confidently identified peptides.

  2. Rapid determination of actinides in asphalt samples

    DOE PAGES

    Maxwell, Sherrod L.; Culligan, Brian K.; Hutchison, Jay B.

    2014-01-12

    A new rapid method for the determination of actinides in asphalt samples has been developed that can be used in emergency response situations or for routine analysis If a radiological dispersive device (RDD), Improvised Nuclear Device (IND) or a nuclear accident such as the accident at the Fukushima Nuclear Power Plant in March, 2011 occurs, there will be an urgent need for rapid analyses of many different environmental matrices, including asphalt materials, to support dose mitigation and environmental clean up. The new method for the determination of actinides in asphalt utilizes a rapid furnace step to destroy bitumen and organicsmore » present in the asphalt and sodium hydroxide fusion to digest the remaining sample. Sample preconcentration steps are used to collect the actinides and a new stacked TRU Resin + DGA Resin column method is employed to separate the actinide isotopes in the asphalt samples. The TRU Resin plus DGA Resin separation approach, which allows sequential separation of plutonium, uranium, americium and curium isotopes in asphalt samples, can be applied to soil samples as well.« less

  3. Rapid determination of actinides in asphalt samples

    SciTech Connect

    Maxwell, Sherrod L.; Culligan, Brian K.; Hutchison, Jay B.

    2014-01-12

    A new rapid method for the determination of actinides in asphalt samples has been developed that can be used in emergency response situations or for routine analysis If a radiological dispersive device (RDD), Improvised Nuclear Device (IND) or a nuclear accident such as the accident at the Fukushima Nuclear Power Plant in March, 2011 occurs, there will be an urgent need for rapid analyses of many different environmental matrices, including asphalt materials, to support dose mitigation and environmental clean up. The new method for the determination of actinides in asphalt utilizes a rapid furnace step to destroy bitumen and organics present in the asphalt and sodium hydroxide fusion to digest the remaining sample. Sample preconcentration steps are used to collect the actinides and a new stacked TRU Resin + DGA Resin column method is employed to separate the actinide isotopes in the asphalt samples. The TRU Resin plus DGA Resin separation approach, which allows sequential separation of plutonium, uranium, americium and curium isotopes in asphalt samples, can be applied to soil samples as well.

  4. Rapid On-Site Environmental Sampling and Analysis of Propellant Stabilizers and their Decomposition Products by Portable Sampling and Thin-Layer Chromotography Kits

    SciTech Connect

    Haas, J S; Gonzalez, M A

    2003-08-04

    Sustainable future use of land containing unexploded ordnance requires extensive field assessments, cleanup, and restoration. The ordnance is generally semi-exposed or buried in pits and, because of aging, needs to be handled with caution. Being able to characterize the ordnance in the field to minimize handling, as well as to distinguish it from inert mock material, greatly facilitates assessments and clean-up. We have developed unique sample preparation methodologies and a portable thin-layer chromatography (TLC) kit technology for rapid field screening and quantitative assessment of stabilizer content in propellants and, energetic materials (explosives) in environmental scenarios. Major advantages of this technology include simultaneous chromatography of multiple samples and standards for high sample throughput, high resolution, very low detection limits, and ease of operation. The TLC kit technology, sponsored by the Defense Ammunition Center (DAC) of the U.S. Army, is now patented and has been completely transitioned to our commercial partners, Ho'olana Technologies, located in Hilo, Hawaii. Once fully deployed in the field, the new technology will demonstrate a cost-effective and efficient means for determining the percent of effective stabilizer that is remaining on-site and at munitions clean-up sites, as well as munitions storage facilities. The TLC kit technology is also readily applicable for analysis at military or commercial facilities, for a variety of emergency and non-emergency scenarios, and for situations where public concern is high.

  5. Ganoderma species discrimination by dual-mode chromatographic fingerprinting: a study on stationary phase effects in hydrophilic interaction chromatography and reduction of sample misclassification rate by additional use of reversed-phase chromatography.

    PubMed

    Chen, Yi; Bicker, Wolfgang; Wu, Junyan; Xie, Ming Yong; Lindner, Wolfgang

    2010-02-19

    Acetonitrile-water extracts of several Ganoderma species - a mushroom being used in Traditional Chinese Medicine - were analysed by liquid chromatography-UV detection in hydrophilic interaction chromatography (HILIC) and reversed-phase (RP) elution modes. A set of six polar stationary phases was used for HILIC runs. These columns had remarkably different separation properties under binary gradient conditions as evinced by hierarchical cluster analysis on retention patterns of seven test compounds. Complementary measurements of RP chromatograms were carried out on a C(18) packing. Injection precision (n=5) and intra-day precision (n=5) were each <2.0% RSD (HILIC) and <0.7% RSD (RP) for relative retention times of main characteristic peaks of a sample extract while for relative peak areas RSD values were max. 6.8%. Repetitive analysis (n=7) of a processed sample stored in the autosampler tray for 48h was used to confirm within-sequence sample stability. Eleven Ganoderma lucidum samples served as training set for the construction of column-specific simulated mean chromatograms. Validation with twelve samples comprising G. lucidum, Ganoderma sinense, Ganoderma atrum, and Ganoderma tsugae by correlation coefficient based similarity evaluation of peak patterns showed that a discrimination of G. lucidum from other Ganoderma species by means of chromatographic fingerprints is conceptually possible on all columns, except of a bare silica packing. The importance of the combined use of RP and HILIC fingerprints to improve the rate of correct sample classification was demonstrated by the fact that each one G. sinense specimen was wrongly assigned being G. lucidum by all HILIC fingerprints but not the RP fingerprint and vice versa. The present data revealed that (i) the analysis of complex biological materials by quasi orthogonal chromatographic modes such as HILIC and RP may deliver more discriminative information than single-mode approaches which strengthens the reliability

  6. Ochratoxin A in cocoa and chocolate sampled in Canada.

    PubMed

    Turcotte, A-M; Scott, P M

    2011-06-01

    In order to determine the levels of ochratoxin A (OTA) in cocoa and cocoa products available in Canada, a previously published analytical method, with minor modifications to the extraction and immunoaffinity clean-up and inclusion of an evaporation step, was initially used (Method I). To improve the low method recoveries (46-61%), 40% methanol was then included in the aqueous sodium bicarbonate extraction solvent (pH 7.8) (Method II). Clean-up was on an Ochratest™ immunoaffinity column and OTA was determined by liquid chromatography (LC) with fluorescence detection. Recoveries of OTA from spiked cocoa powder (0.5 and 5 ng g(-1)) were 75-84%; while recoveries from chocolate were 93-94%. The optimized method was sensitive (limit of quantification (LOQ) = 0.07-0.08 ng g(-1)), accurate (recovery = 75-94%) and precise (coefficient of variation (CV) < 5%). It is applicable to cocoa and chocolate. Analysis of 32 samples of cocoa powder (16 alkalized and 16 natural) for OTA showed an incidence of 100%, with concentrations ranging from 0.25 to 7.8 ng g(-1); in six samples the OTA level exceeded 2 ng g(-1), the previously considered European Union limit for cocoa. The frequency of detection of OTA in 28 chocolate samples (21 dark or baking chocolate and seven milk chocolate) was also 100% with concentrations ranging from 0.05 to 1.4 ng g(-1); one sample had a level higher than the previously considered European Union limit for chocolate (1 ng g(-1)). PMID:21623500

  7. Determination of aflatoxins in rice samples by ultrasound-assisted matrix solid-phase dispersion.

    PubMed

    Manoochehri, Mahboobeh; Asgharinezhad, Ali Akbar; Safaei, Mahdi

    2015-01-01

    This work describes the application of ultrasound-assisted matrix solid-phase dispersion as an extraction and sample preparation approach for aflatoxins (B1, B2, G1 and G2) and subsequent determination of them by high-performance liquid chromatography-fluorescence detection. A Box-Behnken design in combination with response surface methodology was used to determine the affecting parameters on the extraction procedure. The influence of different variables including type of dispersing phase, sample-to-dispersing phase ratio, type and quantity of clean-up phase, ultrasonication time, ultrasonication temperature, nature and volume of the elution solvent was investigated in the optimization study. C18, primary-secondary amine (PSA) and acetonitrile were selected as dispersing phase, clean-up phase and elution solvent, respectively. The obtained optimized values were sample-to-dispersing phase ratio of 1 : 1, 60 mg of PSA, 11 min ultrasonication time, 30°C ultrasonication temperature and 4 mL acetonitrile. Under the optimal conditions, the limits of detection were ranged from 0.09 to 0.14 ng g(-1) and the precisions [relative standard deviation (RSD%)] were <8.6%. The recoveries of the matrix solid-phase dispersion process ranged from 78 to 83% with RSD <10% in all cases. Finally, this method was successfully applied to the extraction of trace amounts of aflatoxins in rice samples.

  8. Analysis of polychlorinated dibenzo-p-dioxins, dibenzofurans and dioxin-like polychlorinated biphenyls in vegetable oil samples by gas chromatography-ion trap tandem mass spectrometry.

    PubMed

    Malavia, J; Abalos, M; Santos, F J; Abad, E; Rivera, J; Galceran, M T

    2007-05-18

    Gas chromatography coupled to ion trap tandem mass spectrometry (CG-MS-MS) has been evaluated for the analysis of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in vegetable oil samples containing different concentration levels (0.2-6 pg WHO-TEQ g(-1) for both PCDD/Fs and dl-PCBs) of the 29 toxic congeners of PCDD/F and dioxin-like PCBs. The effect of potential interfering compounds such as polychlorinated naphthalenes (PCNs), polychlorinated biphenyls (PCBs) and polychlorinated diphenylethers (PCDEs) on the quantification of mono-ortho PCBs has been investigated. In addition, the influence of the clean-up procedure on the final determination by CG-MS-MS was studied, showing that the quality of the results depends to a great extent on this analytical step. Quality parameters have been established and good precisions (CV: 3-19%) and low limits of detection for PCDD/Fs (0.04-0.20 pg g(-1) oil) and dl-PCBs (0.08-0.64 pg g(-1) oil) were obtained. The method was validated by a comparison of the CG-MS-MS results with those obtained by GC-HRMS.

  9. Multivariate optimisation of an ultrasound assisted-matrix solid-phase dispersion method combined with LC-fluorescence detection for simultaneous extraction and determination of aflatoxins in pistachio nut samples.

    PubMed

    Manoochehri, Mahboobeh; Asgharinezhad, Ali Akbar; Safaei, Mahdi

    2013-01-01

    This paper describes the application of ultrasound-assisted matrix solid-phase dispersion as an extraction and clean-up procedure for aflatoxins (B1, B2, G1 and G2) and subsequent determination by LC-fluorescence detection. A Box-Behnken design was used to determine the parameters influencing the extraction procedure through response surface methodology and experimental design. The influence of different variables including type of dispersing phase, sample-to-dispersing phase ratio, type and quantity of clean-up phase, ultrasonication time, ultrasonication temperature, nature and volume of the elution solvent were investigated in the optimisation study. C18, graphitic carbon black and acetonitrile were selected as dispersing phase, clean-up phase and elution solvent, respectively. The optimised values were sample-to-dispersing phase ratio of 1:1, 50 mg of graphitic carbon black, 11 min ultrasonication time, 30°C ultrasonication temperature and 3 ml acetonitrile. Under the optimal conditions the limits of detection (LODs) were ranged from 0.04-0.11 µg kg(-1) and the relative standard deviations (RSDs) of the extraction method were less than 8.6%. The recoveries of the matrix solid-phase dispersion process ranged from 74% to 78% with relative standard deviation lower than 9% in all cases. Finally, the matrix solid-phase dispersion was successfully applied to extraction of trace amounts of aflatoxins in pistachio samples. PMID:24053673

  10. Analytical performance of two miniaturised extraction methods for triclosan and methyltriclosan, in fish roe and surimi samples.

    PubMed

    Gonzalo-Lumbreras, R; Sanz-Landaluze, J; Cámara, C

    2014-03-01

    A new and reliable miniaturised QuEChERS-based extraction method combined with a dispersive SPE cleanup procedure for extracting triclosan and methyltriclosan from fish roe and surimi samples was proposed. The effectiveness of different extraction/partition conditions for QuEChERS method was systematically investigated, and the use of acetonitrile extraction solvent and MgSO4, PSA, C18 and Florisil as cleanup reagents was recommended in the final method. Other method based on ultrasonic extraction with ethylacetate and clean-up with SPE was also evaluated for these samples. Different polymeric and silica sorbents for clean up were tested and the combination of Florisil and PSA was finally selected. The performance of these miniaturised sample preparation methods combined with GC-MS with quadrupole detection were compared. Extraction efficiency as well as cleaning effectiveness, laboriousness and speed were taken as criteria for method evaluation. Satisfactory validation parameters, such as linearity, recovery, precision and LODs and LOQs for both developed analytical methods were obtained from fish roe and surimi samples. Finally, both methods were applied to real samples. The sensitivity of the proposed methods was good enough to ensure reliable determination of target analytes at concentration levels commonly found in this kind of samples.

  11. Supercritical fluid extraction of polyhalogenated pollutants from aquaculture and marine environmental samples: a review.

    PubMed

    García-Rodríguez, Diego; Carro-Díaz, Antonia María; Lorenzo-Ferreira, Rosa Antonia

    2008-05-01

    This article focuses on the state-of-the-art in sample preparation using supercritical fluid extraction (SFE), to monitor the content of polyhalogenated pollutants in aquaculture and marine environmental samples. Marine sediments and biological applications, including several types of samples matrices (fish, shellfish, seaweed and fish feed) and analyte groups (polychlorinated biphenyls (PCBs), polybrominated biphenyls (PBBs), polybrominated diphenylethers (PBDEs), polychlorinated dibenzo-p-dioxin (PCDD)/Fs and organochlorinated pesticide (OCPs)) are discussed with respect to SFE use and optimisation of conditions. We also discuss the great analytical potential of SFE, the integration of the extraction and clean-up steps for rapid sample processing justifying its use for routine work. The most recent SFE applications to the determination of these pollutants in marine environmental (biota and sediment) samples, published in the last 15 years, are reviewed. PMID:18398865

  12. Hollow fiber supported ionic liquid membrane microextraction for determination of sulfonamides in environmental water samples by high-performance liquid chromatography.

    PubMed

    Tao, Yong; Liu, Jing-Fu; Hu, Xia-Lin; Li, Hong-Cheng; Wang, Thanh; Jiang, Gui-Bin

    2009-08-28

    By using ionic liquid as membrane liquid and tri-n-octylphosphine oxide (TOPO) as additive, hollow fiber supported liquid phase microextraction (HF-LPME) was developed for the determination of five sulfonamides in environmental water samples by high-performance liquid chromatography with ultraviolet detection The extraction solvent and the parameters affecting the extraction enrichment factor such as the type and amount of carrier, pH and volume ratio of donor phase and acceptor phase, extraction time, salt-out effect and matrix effect were optimized. Under the optimal extraction conditions (organic liquid membrane phase: [C(8)MIM][PF(6)] with 14% TOPO (w/v); donor phase: 4mL, pH 4.5 KH(2)PO(4) with 2M Na(2)SO(4); acceptor phase: 25microL, pH 13 NaOH; extraction time: 8 h), low detection limits (0.1-0.4microg/L, RSDor=0.999) were obtained for all the analytes. The presence of humic acid (0-25mg/L dissolved organic carbon) and bovine serum albumin (0-100microg/mL) had no significant effect on the extraction efficiency. Good spike recoveries over the range of 82.2-103.2% were obtained when applying the proposed method on five real environmental water samples. These results indicated that this present method was very sensitive and reliable with good repeatabilities and excellent clean-up in water samples. The proposed method confirmed hollow fiber supported ionic liquid membrane based LPME to be robust to monitoring trace levels of sulfadiazine, sulfamerazine, sulfamethazine, sulfadimethoxine and sulfamethoxazole in aqueous samples.

  13. Middlesex Sampling Plant environmental report for calendar year 1992, 239 Mountain Avenue, Middlesex, New Jersey. Formerly Utilized Sites Remedial Action Program (FUSRAP)

    SciTech Connect

    Not Available

    1993-05-01

    This report describes the environmental surveillance program at the Middlesex Sampling Plant (MSP) and provides the results for 1992. The site, in the Borough of Middlesex, New Jersey, is a fenced area and includes four buildings and two storage piles that contain 50,800 m{sup 3} of radioactive and mixed hazardous waste. More than 70 percent of the MSP site is paved with asphalt. The MSP facility was established in 1943 by the Manhattan Engineer District (MED) to sample, store, and/or ship uranium, thorium, and beryllium ores. In 1955 the Atomic Energy Commission (AEC), successor to MED, terminated the operation and later used the site for storage and limited sampling of thorium residues. In 1967 AEC activities ceased, onsite structures were decontaminated, and the site was certified for unrestricted use under criteria applicable at that time. In 1980 the US Department of Energy (DOE) initiated a multiphase remedial action project to clean up several vicinity properties onto which contamination from the plant had migrated. Material from these properties was consolidated into the storage piles onsite. Environmental surveillance of MSP began in 1980 when Congress added the site to DOE`s Formerly Utilized Sites Remedial Action Program. The environmental surveillance program at MSP includes sampling networks for radon and thoron in air; external gamma radiation exposure; and radium-226, radium-228, thorium-230, thorium-232, and total uranium in surface water, sediment, and groundwater. Additionally, chemical analyses are performed to detect metals and organic compounds in surface water and groundwater and metals in sediments. This program assists in fulfilling th DOE policy of measuring and monitoring effluents from DOE activities and calculating hypothetical doses.

  14. Determination of insoluble soap in agricultural soil and sewage sludge samples by liquid chromatography with ultraviolet detection.

    PubMed

    Cantarero, Samuel; Zafra-Gómez, Alberto; Ballesteros, Oscar; Navalón, Alberto; Vílchez, José L; Crovetto, Guillermo; Verge, Coral; de Ferrer, Juan A

    2010-11-01

    We have developed a new analytical procedure for determining insoluble Ca and Mg fatty acid salts (soaps) in agricultural soil and sewage sludge samples. The number of analytical methodologies that focus in the determination of insoluble soap salts in different environmental compartments is very limited. In this work, we propose a methodology that involves a sample clean-up step with petroleum ether to remove soluble salts and a conversion of Ca and Mg insoluble salts into soluble potassium salts using tripotassium ethylenediaminetetraacetate salt and potassium carbonate, followed by the extraction of analytes from the samples using microwave-assisted extraction with methanol. An improved esterification procedure using 2,4-dibromoacetophenone before the liquid chromatography with ultraviolet detection analysis also has been developed. The absence of matrix effect was demonstrated with two fatty acid Ca salts that are not commercial and are never detected in natural samples (C₁₃:₀ and C₁₇:₀). Therefore, it was possible to evaluate the matrix effect because both standards have similar environmental behavior (adsorption and precipitation) to commercial soaps (C₁₀:₀) to C₁₈:₀). We also studied the effect of the different variables on the clean-up, the conversion of Ca soap, and the extraction and derivatization procedures. The quantification limits found ranged from 0.4 to 0.8 mg/kg. The proposed method was satisfactorily applied for the development of a study on soap behavior in agricultural soil and sewage sludge samples.

  15. Investigations into the feasibility of routine ultra high performance liquid chromatography-tandem mass spectrometry analysis of equine hair samples for detecting the misuse of anabolic steroids, anabolic steroid esters and related compounds.

    PubMed

    Gray, Bobby P; Viljanto, Marjaana; Bright, Jane; Pearce, Clive; Maynard, Steve

    2013-07-17

    The detection of the abuse of anabolic steroids in equine sport is complicated by the endogenous nature of some of the abused steroids, such as testosterone and nandrolone. These steroids are commonly administered as intramuscular injections of esterified forms of the steroid, which prolongs their effects and improves bioavailability over oral dosing. The successful detection of an intact anabolic steroid ester therefore provides unequivocal proof of an illegal administration, as esterified forms are not found endogenously. Detection of intact anabolic steroid esters is possible in plasma samples but not, to date, in the traditional doping control matrix of urine. The analysis of equine mane hair for the detection of anabolic steroid esters has the potential to greatly extend the time period over which detection of abuse can be monitored. Equine mane hair samples were incubated in 0.1M phosphate buffer (pH 9.5) before anabolic steroids (testosterone, nandrolone, boldenone, trenbolone and stanozolol), anabolic steroid esters (esters of testosterone, nandrolone, boldenone and trenbolone) and associated compounds (fluticasone propionate and esters of hydroxyprogesterone) were extracted by liquid-liquid extraction with a mix of hexane and ethyl acetate (7:3, v:v). Further sample clean up by solid phase extraction was followed by derivatisation with methoxylamine HCL and analysis by UHPLC-MS/MS. Initial method development was performed on a representative suite of four testosterone esters (propionate, phenylpropionate, isocaproate and decanoate) and the method was later extended to include a further 18 compounds. The applicability of the method was demonstrated by the analysis of mane hair samples collected following the intramuscular administration of 500 mg of Durateston(®) (mixed testosterone esters) to a Thoroughbred mare (560 kg). The method was subsequently used to successfully detect boldenone undecylenate and stanozolol in hair samples collected following

  16. Preservation of samples for dissolved mercury

    USGS Publications Warehouse

    Hamlin, S.N.

    1989-01-01

    Water samples for dissolved mercury requires special treatment because of the high chemical mobility and volatility of this element. Widespread use of mercury and its compounds has provided many avenues for contamination of water. Two laboratory tests were done to determine the relative permeabilities of glass and plastic sample bottles to mercury vapor. Plastic containers were confirmed to be quite permeable to airborne mercury, glass containers were virtually impermeable. Methods of preservation include the use of various combinations of acids, oxidants, and complexing agents. The combination of nitric acid and potassium dichromate successfully preserved mercury in a large variety of concentrations and dissolved forms. Because this acid-oxidant preservative acts as a sink for airborne mercury and plastic containers are permeable to mercury vapor, glass bottles are preferred for sample collection. To maintain a healthy work environment and minimize the potential for contamination of water samples, mercury and its compounds are isolated from the atmosphere while in storage. Concurrently, a program to monitor environmental levels of mercury vapor in areas of potential contamination is needed to define the extent of mercury contamination and to assess the effectiveness of mercury clean-up procedures.Water samples for dissolved mercury require special treatment because of the high chemical mobility and volatility of this element. Widespread use of mercury and its compounds has provided many avenues for contamination of water. Two laboratory tests were done to determine the relative permeabilities of glass and plastic sample bottles to mercury vapor. Plastic containers were confirmed to be quite permeable to airborne mercury, glass containers were virtually impermeable. Methods of preservation include the use of various combinations of acids, oxidants, and complexing agents. The combination of nitric acid and potassium dichromate successfully preserved mercury in a

  17. Survey of aflatoxins in retail samples of whole and ground black and white peppercorns.

    PubMed

    Adzahan, N; Jalili, M; Jinap, S

    2009-01-01

    A total of 126 local and imported samples of commercial white and black pepper in Malaysia were analysed for aflatoxins B1, B2, G1 and G2 (AFB1, AFB2, AFG1, AFG2) content using high-performance liquid chromatography (HPLC) with a fluorescence detector (FD). An acetonitrile-methanol-water (17 : 29 : 54; v/v) mixture was used as a mobile phase and clean-up was using an immunoaffinity column (IAC). Seventy out of 126 (55.5%) samples were contaminated with total aflatoxins, although only low levels of aflatoxins were found ranging from 0.1 to 4.9 ng g(-1). Aflatoxin B1 showed the highest incidence of contamination and was found in all contaminated samples. There was a significant difference between type of samples and different brands (p < 0.05). The results showed black peppers were more contaminated than white peppers. PMID:24785182

  18. The reaction of an iridium PNP complex with parahydrogen facilitates polarisation transfer without chemical change† †Electronic supplementary information (ESI) available: Sample preparation, signal enhancements and raw data. CCDC 1026865. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c4dt03088e Click here for additional data file. Click here for additional data file.

    PubMed Central

    Holmes, Arthur J.; Rayner, Peter J.; Cowley, Michael J.; Green, Gary G. R.; Whitwood, Adrian C.

    2015-01-01

    The short lived pincer complex [(C5H3N(CH2P(tBu)2)2)Ir(H)2(py)]BF4 is shown to be active for signal amplification by reversible exchange. This catalyst formulation enables the efficient transfer of polarization from parahydrogen to be placed into just a single molecule of the hyperpolarisation target, pyridine. When the catalysts 1H nuclei are replaced by 2H, increased levels of substrate hyperpolarization result and when the reverse situation is examined the catalyst itself is clearly visible through hyperpolarised signals. The ligand exchange pathways of [(C5H3N(CH2P(tBu)2)2)Ir(H)2(py)]BF4 that are associated with this process are shown to involve the formation of 16-electron [(C5H3N(CH2P(tBu)2)2)Ir(H)2]BF4 and the 18-electron H2 addition product [(C5H3N(CH2P(tBu)2)2)Ir(H)2(H2)]BF4. PMID:25410259

  19. Development and validation of an on-line multidimensional SPE-LC-MS/MS method for the quantitation of Tetrandrine in blood samples.

    PubMed

    Caglar, Sena; Morello, Rosa; Boos, Karl-Siegfried

    2015-04-15

    On-line solid-phase extraction (SPE) is becoming an increasingly widespread technique in the clean-up of complex matrices such as body fluids, prior to chromatographic analysis. The use of small SPE columns instead of disposable SPE cartridges allows multiple injections and complete automation. In addition, it decreases the cost of consumables and improves the quality of the overall analysis. Coupling of SPE with HPLC combines sample preparation and separation in one system. In this paper a validated on-line multidimensional (MD) SPE-LC-MS/MS method is described for the determination of Tetrandrine (model drug) in human blood samples. The developed method showed the applicability of direct injection of plasma samples to an on-line MD-SPE-LC-MS/MS system to determine small molecules i.e. drugs. The experimental design is unique. Quantification was through tandem mass spectrometry with positive electrospray ionization (ESI) and multiple reactions monitoring (MRM). The limit of detection was calculated as 31.98 ng/mL. The linear range of the method was between 40.0 and 800.0 ng/mL. Pharmacokinetic parameters are usually determined by analysis of drug concentrations in plasma rather than whole blood. Parameters determined using plasma data may be misleading if concentrations of drug differ between plasma and red blood cells. We successfully applied the developed method for the determination of the distribution coefficient of the model drug Tetrandrine between human red blood cells and blood plasma proteins. The determination of distribution coefficient study results demonstrated that the developed method can provide direct and accurate measurement of RBC partitioning in a model drug and could be applied for screening of other compounds for potential high RBC partition, predicting potential drug toxicity and investigating mechanisms associated with RBC partitions. PMID:25746132

  20. Simultaneous qualitative and quantitative analysis of 21 mycotoxins in Radix Paeoniae Alba by ultra-high performance liquid chromatography quadrupole linear ion trap mass spectrometry and QuEChERS for sample preparation.

    PubMed

    Xing, Yanyan; Meng, Wenting; Sun, Wanyang; Li, Dongxiang; Yu, Zhiguo; Tong, Ling; Zhao, Yunli

    2016-09-15

    A high-throughput method for simultaneous qualitative and quantitative analysis of 21 mycotoxins in Radix Paeoniae Alba (RPA) was developed by coupling the modified QuEChERS method with ultra-high performance liquid chromatography quadrupole linear ion trap mass spectrometry (UHPLC-QqLIT-MS). The 21 mycotoxins were extracted and cleaned up using QuEChERS-based procedure, then further separated on a C18 column and detected by a hybrid triple quadrupole linear ion trap mass spectrometer equipped with electrospray ionization source in the multiple reaction monitoring-information dependent acquisition-enhanced product ion (MRM-IDA-EPI) mode. Under this technique, 13 mycotoxins were detected using acetonitrile and water containing 0.1% formic acid as the mobile phase in positive mode while the other 8 mycotoxins were detected using acetonitrile and water containing 0.1% ammonia as the mobile phase in negative mode. The calibration curves of all analytes showed good linearity (r(2)>0.995) within test ranges. The limits of detection and quantification ranged from 0.031 to 5.4μg/kg and 0.20 to 22μg/kg, respectively. Additionally, recoveries were all above 75.3% with relative standard deviations within 15%. The method proposed herein with significant advantages including simple pretreatment, rapid determination as well as high sensitivity, accuracy and throughput would be a preferred candidate for the determination and quantification of multi-class mycotoxin contaminants in real samples. PMID:27500642

  1. Extension of the standard addition method by blank addition.

    PubMed

    Steliopoulos, Panagiotis

    2015-01-01

    Standard addition involves adding varying amounts of the analyte to sample portions of fixed mass or fixed volume and submitting those portions to the sample preparation procedure. After measuring the final extract solutions, the observed signals are linearly regressed on the spiked amounts. The original unknown amount is estimated by the opposite of the abscissa intercept of the fitted straight line [1]. A limitation of this method is that only data points with abscissa values equal to and greater than zero are available so that there is no information on whether linearity holds below the spiking level zero. An approach to overcome this limitation is introduced.•Standard addition is combined with blank addition.•Blank addition means that defined mixtures of blank matrix and sample material are subjected to sample preparation to give final extract solutions.•Equations are presented to estimate the original unknown amount and to calculate the 1-2α confidence interval about this estimate using the combined data set.

  2. Extension of the standard addition method by blank addition

    PubMed Central

    Steliopoulos, Panagiotis

    2015-01-01

    Standard addition involves adding varying amounts of the analyte to sample portions of fixed mass or fixed volume and submitting those portions to the sample preparation procedure. After measuring the final extract solutions, the observed signals are linearly regressed on the spiked amounts. The original unknown amount is estimated by the opposite of the abscissa intercept of the fitted straight line [1]. A limitation of this method is that only data points with abscissa values equal to and greater than zero are available so that there is no information on whether linearity holds below the spiking level zero. An approach to overcome this limitation is introduced.•Standard addition is combined with blank addition.•Blank addition means that defined mixtures of blank matrix and sample material are subjected to sample preparation to give final extract solutions.•Equations are presented to estimate the original unknown amount and to calculate the 1-2α confidence interval about this estimate using the combined data set. PMID:26844210

  3. Sample Design.

    ERIC Educational Resources Information Center

    Ross, Kenneth N.

    1987-01-01

    This article considers various kinds of probability and non-probability samples in both experimental and survey studies. Throughout, how a sample is chosen is stressed. Size alone is not the determining consideration in sample selection. Good samples do not occur by accident; they are the result of a careful design. (Author/JAZ)

  4. Determining the extragalactic extinction law with SALT - II. Additional sample

    NASA Astrophysics Data System (ADS)

    Finkelman, Ido; Brosch, Noah; Kniazev, Alexei Y.; Väisänen, Petri; Buckley, David A. H.; O'Donoghue, Darragh; Gulbis, Amanda; Hashimoto, Yas; Loaring, Nicola; Romero-Colmenero, Encarni; Sefako, Ramotholo

    2010-12-01

    We present new results from an ongoing programme to study the dust extragalactic extinction law in E/S0 galaxies with dust lanes with the Southern African Large Telescope (SALT) during its performance verification phase. The wavelength dependence of the dust extinction for seven galaxies is derived in six spectral bands ranging from the near-ultraviolet atmospheric cut-off to the near-infrared. The derivation of an extinction law is performed by fitting model galaxies to the unextinguished parts of the image in each spectral band, and subtracting from these the actual images. We compare our results with the derived extinction law in the Galaxy and find them to run parallel to the Galactic extinction curve with a mean total-to-selective extinction value of RV = 2.71 +/- 0.43. We use total optical extinction values to estimate the dust mass for each galaxy, compare these with dust masses derived from IRAS measurements, and find them to range from 104 to 107 Msolar. We study the case of the well-known dust-lane galaxy NGC2685 for which Hubble Space Telescope/Wide Field Planetary Camera 2 (HST/WFPC2) data are available to test the dust distribution on different scales. Our results imply a scale-free dust distribution across the dust lanes, at least within ~1arcsec (~60 pc) regions. Based on observations made with the Southern African Large Telescope (SALT). E-mail: ido@wise.tau.ac.il (IF); noah@wise.tau.ac.il (NB); akniazev@saao.ac.za (AYK); petri@saao.ac.za (PV); dibnob@saao.ac.za (DAHB); dod@saao.ac.za (DO); amanda@saao.ac.za (AG); hashimot@ntnu.edu.tw (YH); nsl@saao.ac.za (NL); erc@saao.ac.za (ER-C); rrs@saao.ac.za (RS)

  5. Different formats of imprinted polymers for determining organotin compounds in environmental samples.

    PubMed

    Gallego-Gallegos, Mercedes; Muñoz-Olivas, Riansares; Cámara, Carmen

    2009-02-01

    Organotin compounds and their degradation products enter the environment mainly as a result of their use as biocides and antifouling paints. Analysis of these compounds in environmental samples has to be very sensitive and selective so that their concentrations corresponding to the low environmental target values can also be detected. Generally, analysis of a complex matrix leads to high interferences during the different process steps; clean-up procedures are recommended to overcome this problem. For the past many years, solid phase extraction by employing imprinted materials has been extensively used for many organic substances that are used for pre-concentration and clean-up purposes with excellent results. Here, we present three different imprinted polymers prepared via bulk, precipitation, and emulsion polymerization methods that use similar compositions. The synthesized polymer particles were characterized morphologically by employing scanning electron microscopy and Brunauer-Emmett-Teller analysis. Binding properties were calculated using the Langmuir-Freundlich isotherm. Depending on the properties of the materials, different analytical applications for complex matrices are proposed. These applications are mainly used on tributyltin and its degradation products for environmental analysis.

  6. Capillary sample

    MedlinePlus

    ... using capillary blood sampling. Disadvantages to capillary blood sampling include: Only a limited amount of blood can be drawn using this method. The procedure has some risks (see below). Capillary ...

  7. Rapid cleanup of bacterial DNA from samples containing aerosol contaminants

    NASA Astrophysics Data System (ADS)

    Menking, Darrell E.; Kracke, Suzanne K.; Emanuel, Peter A.; Valdes, James J.

    1999-01-01

    Polymerase Chain Reaction (PCR) is an in vitro enzymatic, synthetic method used to amplify specific DNA sequences from organisms. Detection of DNA using gene probes allows for absolute identification not only of specific organisms, but also of genetic material in recombinant organisms. PCR is an exquisite biological method for detecting bacteria in aerosol samples. A major challenge facing detection of DNA from field samples is that they are almost sure to contain impurities, especially impurities that inhibit amplification through PCR. DNA is being extracted from air, sewage/stool samples, food, sputum, a water and sediment; however, multi- step, time consuming methods are required to isolate the DNA from the surrounding contamination. This research focuses on developing a method for rapid cleanup of DNA which combines extraction and purification of DNA while, at the same time, removing inhibitors from 'dirty samples' to produce purified, PCR-ready DNA. GeneReleaser produces PCR-ready DNA in a rapid five-minute protocol. GeneReleaser resin was able to clean up sample contain micrograms of typical aerosol and water contaminants. The advantages of using GR are that it is rapid, inexpensive, requires one-step, uses no hazardous material and produces PCR-ready DNA.

  8. [Food additives and healthiness].

    PubMed

    Heinonen, Marina

    2014-01-01

    Additives are used for improving food structure or preventing its spoilage, for example. Many substances used as additives are also naturally present in food. The safety of additives is evaluated according to commonly agreed principles. If high concentrations of an additive cause adverse health effects for humans, a limit of acceptable daily intake (ADI) is set for it. An additive is a risk only when ADI is exceeded. The healthiness of food is measured on the basis of nutrient density and scientifically proven effects.

  9. Evaluation of a sampling and analysis method for determination of polyhalogenated dibenzo-p-dioxins and dibenzofurans in ambient air

    SciTech Connect

    Harless, R.L.; Lewis, R.G.; McDaniel, D.D.; Gibson, J.F.; Dupuy, A.E.

    1992-01-01

    General Metals Works PS-1 PUF air samplers and an analytical method based on high resolution gas chromatography - high resolution mass spectrometry (HRGC-HRMS) were evaluated for determination of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/PCDFs), polybrominated dibenz-p-dioxins and dibenzofurans (PBDDs/PBDFs) and bromo/chloro dibenzo-p-dioxins and dibenzofurans (BCDDs/BCDFs) in ambient air. Dilute solutions of these compounds and (13)C-1,2,3,4-TCDD were used to spike the filters of PS-1 air samplers which were then operated 24 hrs to sample 350-400 cubic meter ambient air. After sampling, each quartz-fiber filter and polyurethane foam (PUF) were spiked with (13)C-12-labeled PCDD, PCDF, PBDD, and PBDF internal standards before separate Soxhlet extractions with benzene. The extracts were subjected to an acid/base clean-up procedure followed by clean-up on microcolumns of silica gel, alumina, and carbon and then analyzed by HRGC-HRMS. Results derived from the study indicated the PS-1 ambient air samplers and the analytical procedures were very efficient and that pg/cubic meter and sub-pg/cubic meter levels of total PCDDs/PCDFs, PBDDs/PBDFs, BCDDs/BCDFs, and 2,3,7,8-substituted congeners could be accurately measured.

  10. Superposition Enhanced Nested Sampling

    NASA Astrophysics Data System (ADS)

    Martiniani, Stefano; Stevenson, Jacob D.; Wales, David J.; Frenkel, Daan

    2014-07-01

    The theoretical analysis of many problems in physics, astronomy, and applied mathematics requires an efficient numerical exploration of multimodal parameter spaces that exhibit broken ergodicity. Monte Carlo methods are widely used to deal with these classes of problems, but such simulations suffer from a ubiquitous sampling problem: The probability of sampling a particular state is proportional to its entropic weight. Devising an algorithm capable of sampling efficiently the full phase space is a long-standing problem. Here, we report a new hybrid method for the exploration of multimodal parameter spaces exhibiting broken ergodicity. Superposition enhanced nested sampling combines the strengths of global optimization with the unbiased or athermal sampling of nested sampling, greatly enhancing its efficiency with no additional parameters. We report extensive tests of this new approach for atomic clusters that are known to have energy landscapes for which conventional sampling schemes suffer from broken ergodicity. We also introduce a novel parallelization algorithm for nested sampling.

  11. Powder sampling.

    PubMed

    Venables, Helena J; Wells, J I

    2002-01-01

    The factors involved when sampling powder mixes have been reviewed. The various methods are evaluated (manual, automatic, and sub-sampling) and the errors incurred are discussed. Certain rules have been applied to various samplers and their suitability for powder mixtures are described. The spinning riffler is apparently the most suitable, while the use of sample thieves should be avoided due to error and bias.

  12. Levels of dioxins and dioxin-like PCBs in food samples on the Greek market.

    PubMed

    Papadopoulos, Athanasios; Vassiliadou, Irene; Costopoulou, Danae; Papanicolaou, Christina; Leondiadis, Leondios

    2004-11-01

    Food intake is the main source of exposure to dioxin-like compounds for humans. The results of a surveillance programme on polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and co-planar polychlorinated biphenyls (co-PCBs) in 77 food samples from the Greek market and producers are presented. The study included the analyses of milk and dairy products, meat and meat products, fish, vegetable oil, eggs, fruit, vegetable and rice collected between August and December 2002. After extraction, extracts were cleaned up on a series of carbon column chromatography, silica gel, alumina chromatography, and then analysed by high resolution gas chromatography/high resolution mass spectrometry. All samples had a dioxin content far below the EC Regulation (2375/2001/EC) limits. PMID:15331268

  13. Sampling Development

    PubMed Central

    Adolph, Karen E.; Robinson, Scott R.

    2011-01-01

    Research in developmental psychology requires sampling at different time points. Accurate depictions of developmental change provide a foundation for further empirical studies and theories about developmental mechanisms. However, overreliance on widely spaced sampling intervals in cross-sectional and longitudinal designs threatens the validity of the enterprise. This article discusses how to sample development in order to accurately discern the shape of developmental change. The ideal solution is daunting: to summarize behavior over 24-hour intervals and collect daily samples over the critical periods of change. We discuss the magnitude of errors due to undersampling, and the risks associated with oversampling. When daily sampling is not feasible, we offer suggestions for sampling methods that can provide preliminary reference points and provisional sketches of the general shape of a developmental trajectory. Denser sampling then can be applied strategically during periods of enhanced variability, inflections in the rate of developmental change, or in relation to key events or processes that may affect the course of change. Despite the challenges of dense repeated sampling, researchers must take seriously the problem of sampling on a developmental time scale if we are to know the true shape of developmental change. PMID:22140355

  14. Quantitation of yeast total proteins in sodium dodecyl sulfate-polyacrylamide gel electrophoresis sample buffer for uniform loading.

    PubMed

    Sheen, Hyukho

    2016-04-01

    Proteins in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) sample buffer are difficult to quantitate due to SDS and reducing agents being in the buffer. Although acetone precipitation has long been used to clean up proteins from detergents and salts, previous studies showed that protein recovery from acetone precipitation varies from 50 to 100% depending on the samples tested. Here, this article shows that acetone precipitates proteins highly efficiently from SDS-PAGE sample buffer and that quantitative recovery is achieved in 5 min at room temperature. Moreover, precipitated proteins are resolubilized with urea/guanidine, rather than with SDS. Thus, the resolubilized samples are readily quantifiable with Bradford reagent without using SDS-compatible assays.

  15. Recovery of Cryptosporidium oocysts from small and large volume water samples using a compressed foam filter system.

    PubMed

    Sartory, D P; Parton, A; Parton, A C; Roberts, J; Bergmann, K

    1998-12-01

    A novel filter system comprising open cell reticulated foam rings compressed between retaining plates and fitted into a filtration housing was evaluated for the recovery of oocysts of Cryptosporidium from water. Mean recoveries of 90.2% from seeded small and large volume (100-2000 l) tap water samples, and 88.8% from 10-20 l river water samples, were achieved. Following a simple potassium citrate flotation concentrate clean-up procedure, mean recoveries were 56.7% for the tap water samples and 60.9% for river water samples. This represents a marked improvement in capture and recovery of Cryptosporidium oocysts from water compared with conventional polypropylene wound cartridge filters and membrane filters.

  16. 49 CFR Appendix A to Part 24 - Additional Information

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... not a displaced person under this part may file an appeal in accordance with 49 CFR part 24.10 of this... not include program benefits that are not considered income by Federal law such as food stamps and the... relocation may precede acquisition. Superfund is a program designed to clean up hazardous waste sites....

  17. 49 CFR Appendix A to Part 24 - Additional Information

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... not a displaced person under this part may file an appeal in accordance with 49 CFR part 24.10 of this... not include program benefits that are not considered income by Federal law such as food stamps and the... relocation may precede acquisition. Superfund is a program designed to clean up hazardous waste sites....

  18. 49 CFR Appendix A to Part 24 - Additional Information

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... not a displaced person under this part may file an appeal in accordance with 49 CFR part 24.10 of this... not include program benefits that are not considered income by Federal law such as food stamps and the... relocation may precede acquisition. Superfund is a program designed to clean up hazardous waste sites....

  19. 49 CFR Appendix A to Part 24 - Additional Information

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... not a displaced person under this part may file an appeal in accordance with 49 CFR part 24.10 of this... not include program benefits that are not considered income by Federal law such as food stamps and the... relocation may precede acquisition. Superfund is a program designed to clean up hazardous waste sites....

  20. Sampling Development

    ERIC Educational Resources Information Center

    Adolph, Karen E.; Robinson, Scott R.

    2011-01-01

    Research in developmental psychology requires sampling at different time points. Accurate depictions of developmental change provide a foundation for further empirical studies and theories about developmental mechanisms. However, overreliance on widely spaced sampling intervals in cross-sectional and longitudinal designs threatens the validity of…

  1. 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.

  2. 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.

  3. Optimisation of sample treatment for arsenic speciation in alga samples by focussed sonication and ultrafiltration.

    PubMed

    Salgado, S García; Quijano Nieto, M A; Bonilla Simón, M M

    2006-02-28

    A procedure for arsenic species fractionation in alga samples (Sargassum fulvellum, Chlorella vulgaris, Hizikia fusiformis and Laminaria digitata) by extraction is described. Several parameters were tested in order to evaluate the extraction efficiency of the process: extraction medium, nature and concentration (tris(hydroxymethyl)aminomethane, phosphoric acid, deionised water and water/methanol mixtures), extraction time and physical treatment (magnetic stirring, ultrasonic bath and ultrasonic focussed probe). The extraction yield of arsenic under the different conditions was evaluated by determining the total arsenic content in the extracts by ICP-AES. Arsenic compounds were extracted in 5mL of water by focussed sonication for 30s and subsequent centrifugation at 14,000xg for 10min. The process was repeated three times. Extraction studies show that soluble arsenic compounds account for about 65% of total arsenic. An ultrafiltration process was used as a clean-up method for chromatographic analysis, and also allowed us to determine the extracted arsenic fraction with a molecular weight lower than 10kDa, which accounts for about 100% for all samples analysed. Speciation studies were carried out by HPLC-ICP-AES. Arsenic species were separated on a Hamilton PRP-X100 column with 17mM phosphate buffer at pH 5.5 and 1.0mLmin(-1) flow rate. The chromatographic method allowed us to separate the species As(III), As(V), MMA and DMA in less than 13min, with detection limits of about 20ng of arsenic per species, for a sample injection volume of 100muL. The chromatographic analysis allowed us to identify As(V) in Hizikia (46+/-2mugg(-1)), Sargassum (38+/-2mugg(-1)) and Chlorella (9+/-1mugg(-1)) samples. The species DMA was also found in Chlorella alga (13+/-1mugg(-1)). However, in Laminaria alga only an unknown arsenic species was detected, which eluted in the dead volume.

  4. Lunar Sample Compendium

    NASA Technical Reports Server (NTRS)

    Meyer, C.

    2009-01-01

    The Lunar Sample Compendium is a succinct summary of what has been learned from the study of Apollo and Luna samples of the Moon. Basic information is compiled, sample-by-sample, in the form of an advanced catalog in order to provide a basic description of each sample. Information presented is carefully attributed to the original source publication, thus the Compendium also serves as a ready access to the now vast scientific literature pertaining to lunar smples. The Lunar Sample Compendium is a work in progress (and may always be). Future plans include: adding sections on additional samples, adding new thin section photomicrographs, replacing the faded photographs with newly digitized photos from the original negatives, attempting to correct the age data using modern decay constants, adding references to each section, and adding an internal search engine.

  5. Simultaneous determination of 19 triazine pesticides and degradation products in processed cereal samples from Chinese total diet study by isotope dilution-high performance liquid chromatography-linear ion trap mass spectrometry.

    PubMed

    Li, Peng; Yang, Xin; Miao, Hong; Zhao, Yunfeng; Liu, Wei; Wu, Yongning

    2013-06-01

    A selective and sensitive isotope dilution-high performance liquid chromatography-linear ion trap mass spectrometry (Isotope Dilution-HPLC-LIT-MS(3)) method was developed for the simultaneous determination of 19 triazine pesticides and their degradation products in processed cereal samples from Chinese total diet study (TDS). The method integrated the addition of isotope internal standards, liquid-liquid extraction (LLE), clean-up with MCX solid-phase extraction (SPE) cartridges and HPLC-LIT-MS(3) analysis with selected reaction monitoring (SRM) mode. Matrix-matched calibration curves showed good linearity (R(2)≥0.9940) verified by applying the Mandel's fitting test (p>0.087) performed at the 95% confidence level. Decision limits (CCαs) and detection capabilities (CCβs) of the 19 triazine pesticides and their degradation products fell in the ranges of 0.0020-0.4200 μg kg(-1) and 0.0024-0.4500 μg kg(-1), respectively. Recoveries ranged from 70.1% to 112.8%, with the relative standard deviations (RSDs) ranging from 1.5% to 13.5%. Furthermore, the proposed method was applied to analyzing the proposed cereal samples from the fourth Chinese TDS. Eleven triazines were detected in six cereal samples with the concentrations ranging from 0.013 to 0.987 μg kg(-1). This method can also be used for the further determination of the triazines in other food group composites, and ultimately served as a methodological foundation for assessing the triazines in the average Chinese diet in the general population. PMID:23684466

  6. Elevating sampling

    PubMed Central

    Labuz, Joseph M.; Takayama, Shuichi

    2014-01-01

    Sampling – the process of collecting, preparing, and introducing an appropriate volume element (voxel) into a system – is often under appreciated and pushed behind the scenes in lab-on-a-chip research. What often stands in the way between proof-of-principle demonstrations of potentially exciting technology and its broader dissemination and actual use, however, is the effectiveness of sample collection and preparation. The power of micro- and nanofluidics to improve reactions, sensing, separation, and cell culture cannot be accessed if sampling is not equally efficient and reliable. This perspective will highlight recent successes as well as assess current challenges and opportunities in this area. PMID:24781100

  7. SAMPLING SYSTEM

    DOEpatents

    Hannaford, B.A.; Rosenberg, R.; Segaser, C.L.; Terry, C.L.

    1961-01-17

    An apparatus is given for the batch sampling of radioactive liquids such as slurries from a system by remote control, while providing shielding for protection of operating personnel from the harmful effects of radiation.

  8. Polyimide processing additives

    NASA Technical Reports Server (NTRS)

    Fletcher, James C. (Inventor); Pratt, J. Richard (Inventor); St.clair, Terry L. (Inventor); Stoakley, Diane M. (Inventor); Burks, Harold D. (Inventor)

    1992-01-01

    A process for preparing polyimides having enhanced melt flow properties is described. The process consists of heating a mixture of a high molecular weight poly-(amic acid) or polyimide with a low molecular weight amic acid or imide additive in the range of 0.05 to 15 percent by weight of additive. The polyimide powders so obtained show improved processability, as evidenced by lower melt viscosity by capillary rheometry. Likewise, films prepared from mixtures of polymers with additives show improved processability with earlier onset of stretching by TMA.

  9. Polyimide processing additives

    NASA Technical Reports Server (NTRS)

    Pratt, J. Richard (Inventor); St.clair, Terry L. (Inventor); Stoakley, Diane M. (Inventor); Burks, Harold D. (Inventor)

    1993-01-01

    A process for preparing polyimides having enhanced melt flow properties is described. The process consists of heating a mixture of a high molecular weight poly-(amic acid) or polyimide with a low molecular weight amic acid or imide additive in the range of 0.05 to 15 percent by weight of the additive. The polyimide powders so obtained show improved processability, as evidenced by lower melt viscosity by capillary rheometry. Likewise, films prepared from mixtures of polymers with additives show improved processability with earlier onset of stretching by TMA.

  10. Additional Types of Neuropathy

    MedlinePlus

    ... A A Listen En Español Additional Types of Neuropathy Charcot's Joint Charcot's Joint, also called neuropathic arthropathy, ... can stop bone destruction and aid healing. Cranial Neuropathy Cranial neuropathy affects the 12 pairs of nerves ...

  11. Food Additives and Hyperkinesis

    ERIC Educational Resources Information Center

    Wender, Ester H.

    1977-01-01

    The hypothesis that food additives are causally associated with hyperkinesis and learning disabilities in children is reviewed, and available data are summarized. Available from: American Medical Association 535 North Dearborn Street Chicago, Illinois 60610. (JG)

  12. Smog control fuel additives

    SciTech Connect

    Lundby, W.

    1993-06-29

    A method is described of controlling, reducing or eliminating, ozone and related smog resulting from photochemical reactions between ozone and automotive or industrial gases comprising the addition of iodine or compounds of iodine to hydrocarbon-base fuels prior to or during combustion in an amount of about 1 part iodine per 240 to 10,000,000 parts fuel, by weight, to be accomplished by: (a) the addition of these inhibitors during or after the refining or manufacturing process of liquid fuels; (b) the production of these inhibitors for addition into fuel tanks, such as automotive or industrial tanks; or (c) the addition of these inhibitors into combustion chambers of equipment utilizing solid fuels for the purpose of reducing ozone.

  13. A single-step pesticide extraction and clean-up multi-residue analytical method by selective pressurized liquid extraction followed by on-line solid phase extraction and ultra-high-performance liquid chromatography-tandem mass spectrometry for complex matrices.

    PubMed

    Rodrigues, Elsa Teresa; Pardal, Miguel Ângelo; Salgueiro-González, Noelia; Muniategui-Lorenzo, Soledad; Alpendurada, Maria Fátima

    2016-06-24

    Pesticides, a group of compounds linked to human activity, may, when in toxic levels, have a profound effect on water quality, and hence result in adverse consequences to aquatic life and ultimately to human health. Analytical challenges arise when successfully trying to determine these levels in environmental complex matrices. Therefore, fast, simple, sensitive and selective analytical methodologies for multi-residue determination of pesticides (atrazine, azoxystrobin, bentazon, λ-cyhalothrin, penoxsulam and terbuthylazine) in sediment, macrophytes (algae and aquatic plants) and aquatic animals were developed and validated. The established methods were matrix-dependent and were based on Selective Pressurized Liquid Extraction (SPLE) followed by on-line Solid Phase Extraction and Ultra Performance Liquid Chromatography-tandem Mass Spectrometry (on-line SPE-UPLC-ESI-MS/MS). This cutting-edge research methodology uses a small amount of sample, is time saving and reduces the use of organic solvents in compliance with Green Chemistry principles. The analytical features were adequate for all compounds in all studied matrices. The established methodology was applied on real marine samples and no pesticide concentrations above their respective method quantification limits were measured in sediments or aquatic plants. However, terbuthylazine was found in the macroalgae Ulva spp. (108ngg(-1)dw) and all the prospected pesticides were measured above their respective method quantification limits in the bivalve Scrobicularia plana (atrazine: 48ngg(-1)dw, azoxystrobin: 64ngg(-1)dw, bentazon: 33ngg(-1)dw, λ-cyhalothrin: 2531ngg(-1)dw, penoxsulam: 50ngg(-1)dw, and terbuthylazine: 44ngg(-1)dw). PMID:27234845

  14. Aptamer-targeted magnetic nanospheres as a solid-phase extraction sorbent for determination of ochratoxin A in food samples.

    PubMed

    Wu, Ximei; Hu, Jun; Zhu, Binghui; Lu, Lin; Huang, Xiangdong; Pang, Daiwen

    2011-10-14

    A sorbent based on the aptamer for ochratoxin A was immobilized onto magnetic nanospheres (MNS) and used to develop a magnetic solid-phase extraction procedure to clean up food samples in conjunction with high-performance liquid chromatography separation and fluorescence detection. Specific retention of ochratoxin A by the sorbent was demonstrated, and the capacity of the MNS-aptamer sorbent was determined. The efficacy of this new approach was successfully evaluated through comparison with solid-phase extraction on commercial C18 cartridge. Several different food samples fortified in the range of with 2.5-50 μg/kg yielded mean recoveries from 67% to 90%, respectively. Finally, this oligosorbent was applied to the selective extraction of ochratoxin A from unfortified food samples. PMID:21890142

  15. Determination of fumonisins B1 and B2 in Portuguese maize and maize-based samples by HPLC with fluorescence detection.

    PubMed

    Lino, C M; Silva, L J G; Pena, A L S; Silveira, M I

    2006-03-01

    Fumonisins B(1) (FB1) and fumonisin B2 (FB2) are the main members of a family of mycotoxins produced by Fusarium verticillioides, Fusarium proliferatum, and other fungi species of the section Liseola. The present work shows the results of comparative studies using two different procedures for the analysis of fumonisins in maize and maize-based samples. The studied analytical methods involve extraction with methanol/water, dilution with PBS, and clean-up through immunoaffinity columns. Two reagents (o-phthaldialdehyde and naphthalene-2,3-dicarboxaldehyde) were studied for formation of fluorescent derivatives. The separation and identification were carried out by high-performance liquid chromatography with fluorescence detection. The optimized method for analysis of fumonisins in maize involved extraction with methanol/water (80:20), clean-up with an immunoaffinity column, and derivatization with naphthalene-2,3-dicarboxaldehyde (NDA). The limit of detection was 20 microg kg(-1) for FB1 and 15 microg kg(-1) for FB2. Recoveries of FB1 and FB2 ranged from 79% to 99.6% for maize fortified at 150 microg kg(-1) and 200 microg kg(-1), respectively, with within-day RSDs of 3.0 and 2.7%. The proposed method was applied to 31 samples, and the presence of fumonisins was found in 14 samples at concentrations ranging from 113 to 2,026 microg kg(-1). The estimated daily intake of fumonisins was 0.14 microg kg(-1) body weight per day.

  16. SAMPLING OSCILLOSCOPE

    DOEpatents

    Sugarman, R.M.

    1960-08-30

    An oscilloscope is designed for displaying transient signal waveforms having random time and amplitude distributions. The oscilloscopc is a sampling device that selects for display a portion of only those waveforms having a particular range of amplitudes. For this purpose a pulse-height analyzer is provided to screen the pulses. A variable voltage-level shifter and a time-scale rampvoltage generator take the pulse height relative to the start of the waveform. The variable voltage shifter produces a voltage level raised one step for each sequential signal waveform to be sampled and this results in an unsmeared record of input signal waveforms. Appropriate delay devices permit each sample waveform to pass its peak amplitude before the circuit selects it for display.

  17. Sampling apparatus

    DOEpatents

    Gordon, Norman R.; King, Lloyd L.; Jackson, Peter O.; Zulich, Alan W.

    1989-01-01

    A sampling apparatus is provided for sampling substances from solid surfaces. The apparatus includes first and second elongated tubular bodies which telescopically and sealingly join relative to one another. An absorbent pad is mounted to the end of a rod which is slidably received through a passageway in the end of one of the joined bodies. The rod is preferably slidably and rotatably received through the passageway, yet provides a selective fluid tight seal relative thereto. A recess is formed in the rod. When the recess and passageway are positioned to be coincident, fluid is permitted to flow through the passageway and around the rod. The pad is preferably laterally orientable relative to the rod and foldably retractable to within one of the bodies. A solvent is provided for wetting of the pad and solubilizing or suspending the material being sampled from a particular surface.

  18. Sampling apparatus

    DOEpatents

    Gordon, N.R.; King, L.L.; Jackson, P.O.; Zulich, A.W.

    1989-07-18

    A sampling apparatus is provided for sampling substances from solid surfaces. The apparatus includes first and second elongated tubular bodies which telescopically and sealingly join relative to one another. An absorbent pad is mounted to the end of a rod which is slidably received through a passageway in the end of one of the joined bodies. The rod is preferably slidably and rotatably received through the passageway, yet provides a selective fluid tight seal relative thereto. A recess is formed in the rod. When the recess and passageway are positioned to be coincident, fluid is permitted to flow through the passageway and around the rod. The pad is preferably laterally orientable relative to the rod and foldably retractable to within one of the bodies. A solvent is provided for wetting of the pad and solubilizing or suspending the material being sampled from a particular surface. 15 figs.

  19. Additive Manufacturing Infrared Inspection

    NASA Technical Reports Server (NTRS)

    Gaddy, Darrell

    2014-01-01

    Additive manufacturing is a rapid prototyping technology that allows parts to be built in a series of thin layers from plastic, ceramics, and metallics. Metallic additive manufacturing is an emerging form of rapid prototyping that allows complex structures to be built using various metallic powders. Significant time and cost savings have also been observed using the metallic additive manufacturing compared with traditional techniques. Development of the metallic additive manufacturing technology has advanced significantly over the last decade, although many of the techniques to inspect parts made from these processes have not advanced significantly or have limitations. Several external geometry inspection techniques exist such as Coordinate Measurement Machines (CMM), Laser Scanners, Structured Light Scanning Systems, or even traditional calipers and gages. All of the aforementioned techniques are limited to external geometry and contours or must use a contact probe to inspect limited internal dimensions. This presentation will document the development of a process for real-time dimensional inspection technique and digital quality record of the additive manufacturing process using Infrared camera imaging and processing techniques.

  20. Long-term Effects of Nutrient Addition and Phytoremediation on Diesel and Crude Oil Contaminated Soils in subarctic Alaska.

    PubMed

    Leewis, Mary-Cathrine; Reynolds, Charles M; Leigh, Mary Beth

    2013-12-01

    Phytoremediation is a potentially inexpensive method of detoxifying contaminated soils using plants and associated soil microorganisms. The remote locations and cold climate of Alaska provide unique challenges associated with phytoremediation such as finding effective plant species that can achieve successful site clean-up despite the extreme environmental conditions and with minimal site management. A long-term assessment of phytoremediation was performed which capitalized on a study established in Fairbanks in 1995. The original study sought to determine how the introduction of plants (Festuca rubra, Lolium multiflorum), nutrients (fertilizer), or their combination would affect degradation of petroleum hydrocarbon (TPH) contaminated soils (crude oil or diesel) over time. Within the year following initial treatments, the plots subjected to both planting and/or fertilization showed greater overall decreases in TPH concentrations in both the diesel and crude oil contaminated soils relative to untreated plots. We re-examined this field site after 15 years with no active site management to assess the long-term effects of phytoremediation on colonization by native and non-native plants, their rhizosphere microbial communities and on petroleum removal from soil. Native and non-native vegetation had extensively colonized the site, with more abundant vegetation found on the diesel contaminated soils than the more nutrient-poor, more coarse, and acidic crude oil contaminated soils. TPH concentrations achieved regulatory clean up levels in all treatment groups, with lower TPH concentrations correlating with higher amounts of woody vegetation (trees & shrubs). In addition, original treatment type has affected vegetation recruitment to each plot with woody vegetation and more native plants in unfertilized plots. Bacterial community structure also varies according to the originally applied treatments. This study suggests that initial treatment with native tree species in

  1. Long-term Effects of Nutrient Addition and Phytoremediation on Diesel and Crude Oil Contaminated Soils in subarctic Alaska

    PubMed Central

    Leewis, Mary-Cathrine; Reynolds, Charles M.; Leigh, Mary Beth

    2014-01-01

    Phytoremediation is a potentially inexpensive method of detoxifying contaminated soils using plants and associated soil microorganisms. The remote locations and cold climate of Alaska provide unique challenges associated with phytoremediation such as finding effective plant species that can achieve successful site clean-up despite the extreme environmental conditions and with minimal site management. A long-term assessment of phytoremediation was performed which capitalized on a study established in Fairbanks in 1995. The original study sought to determine how the introduction of plants (Festuca rubra, Lolium multiflorum), nutrients (fertilizer), or their combination would affect degradation of petroleum hydrocarbon (TPH) contaminated soils (crude oil or diesel) over time. Within the year following initial treatments, the plots subjected to both planting and/or fertilization showed greater overall decreases in TPH concentrations in both the diesel and crude oil contaminated soils relative to untreated plots. We re-examined this field site after 15 years with no active site management to assess the long-term effects of phytoremediation on colonization by native and non-native plants, their rhizosphere microbial communities and on petroleum removal from soil. Native and non-native vegetation had extensively colonized the site, with more abundant vegetation found on the diesel contaminated soils than the more nutrient-poor, more coarse, and acidic crude oil contaminated soils. TPH concentrations achieved regulatory clean up levels in all treatment groups, with lower TPH concentrations correlating with higher amounts of woody vegetation (trees & shrubs). In addition, original treatment type has affected vegetation recruitment to each plot with woody vegetation and more native plants in unfertilized plots. Bacterial community structure also varies according to the originally applied treatments. This study suggests that initial treatment with native tree species in

  2. Phenylethynyl Containing Reactive Additives

    NASA Technical Reports Server (NTRS)

    Connell, John W. (Inventor); Smith, Joseph G., Jr. (Inventor); Hergenrother, Paul M. (Inventor)

    2002-01-01

    Phenylethynyl containing reactive additives were prepared from aromatic diamine, containing phenylethvnvl groups and various ratios of phthalic anhydride and 4-phenylethynviphthalic anhydride in glacial acetic acid to form the imide in one step or in N-methyl-2-pvrrolidinone to form the amide acid intermediate. The reactive additives were mixed in various amounts (10% to 90%) with oligomers containing either terminal or pendent phenylethynyl groups (or both) to reduce the melt viscosity and thereby enhance processability. Upon thermal cure, the additives react and become chemically incorporated into the matrix and effect an increase in crosslink density relative to that of the host resin. This resultant increase in crosslink density has advantageous consequences on the cured resin properties such as higher glass transition temperature and higher modulus as compared to that of the host resin.

  3. Multifunctional fuel additives

    SciTech Connect

    Baillargeon, D.J.; Cardis, A.B.; Heck, D.B.

    1991-03-26

    This paper discusses a composition comprising a major amount of a liquid hydrocarbyl fuel and a minor low-temperature flow properties improving amount of an additive product of the reaction of a suitable diol and product of a benzophenone tetracarboxylic dianhydride and a long-chain hydrocarbyl aminoalcohol.

  4. Biobased lubricant additives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fully biobased lubricants are those formulated using all biobased ingredients, i.e. biobased base oils and biobased additives. Such formulations provide the maximum environmental, safety, and economic benefits expected from a biobased product. Currently, there are a number of biobased base oils that...

  5. Sampling Strategy

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Three locations to the right of the test dig area are identified for the first samples to be delivered to the Thermal and Evolved Gas Analyzer (TEGA), the Wet Chemistry Lab (WCL), and the Optical Microscope (OM) on NASA's Phoenix Mars Lander. These sampling areas are informally labeled 'Baby Bear', 'Mama Bear', and 'Papa Bear' respectively. This image was taken on the seventh day of the Mars mission, or Sol 7 (June 1, 2008) by the Surface Stereo Imager aboard NASA's Phoenix Mars Lander.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  6. Vinyl capped addition polyimides

    NASA Technical Reports Server (NTRS)

    Vannucci, Raymond D. (Inventor); Malarik, Diane C. (Inventor); Delvigs, Peter (Inventor)

    1991-01-01

    Polyimide resins (PMR) are generally useful where high strength and temperature capabilities are required (at temperatures up to about 700 F). Polyimide resins are particularly useful in applications such as jet engine compressor components, for example, blades, vanes, air seals, air splitters, and engine casing parts. Aromatic vinyl capped addition polyimides are obtained by reacting a diamine, an ester of tetracarboxylic acid, and an aromatic vinyl compound. Low void materials with improved oxidative stability when exposed to 700 F air may be fabricated as fiber reinforced high molecular weight capped polyimide composites. The aromatic vinyl capped polyimides are provided with a more aromatic nature and are more thermally stable than highly aliphatic, norbornenyl-type end-capped polyimides employed in PMR resins. The substitution of aromatic vinyl end-caps for norbornenyl end-caps in addition polyimides results in polymers with improved oxidative stability.

  7. Tackifier for addition polyimides

    NASA Technical Reports Server (NTRS)

    Butler, J. M.; St.clair, T. L.

    1980-01-01

    A modification to the addition polyimide, LaRC-160, was prepared to improve tack and drape and increase prepeg out-time. The essentially solventless, high viscosity laminating resin is synthesized from low cost liquid monomers. The modified version takes advantage of a reactive, liquid plasticizer which is used in place of solvent and helps solve a major problem of maintaining good prepeg tack and drape, or the ability of the prepeg to adhere to adjacent plies and conform to a desired shape during the lay up process. This alternate solventless approach allows both longer life of the polymer prepeg and the processing of low void laminates. This approach appears to be applicable to all addition polyimide systems.

  8. Electrophilic addition of astatine

    SciTech Connect

    Norseev, Yu.V.; Vasaros, L.; Nhan, D.D.; Huan, N.K.

    1988-03-01

    It has been shown for the first time that astatine is capable of undergoing addition reactions to unsaturated hydrocarbons. A new compound of astatine, viz., ethylene astatohydrin, has been obtained, and its retention numbers of squalane, Apiezon, and tricresyl phosphate have been found. The influence of various factors on the formation of ethylene astatohydrin has been studied. It has been concluded on the basis of the results obtained that the univalent cations of astatine in an acidic medium is protonated hypoastatous acid.

  9. Functional Generalized Additive Models.

    PubMed

    McLean, Mathew W; Hooker, Giles; Staicu, Ana-Maria; Scheipl, Fabian; Ruppert, David

    2014-01-01

    We introduce the functional generalized additive model (FGAM), a novel regression model for association studies between a scalar response and a functional predictor. We model the link-transformed mean response as the integral with respect to t of F{X(t), t} where F(·,·) is an unknown regression function and X(t) is a functional covariate. Rather than having an additive model in a finite number of principal components as in Müller and Yao (2008), our model incorporates the functional predictor directly and thus our model can be viewed as the natural functional extension of generalized additive models. We estimate F(·,·) using tensor-product B-splines with roughness penalties. A pointwise quantile transformation of the functional predictor is also considered to ensure each tensor-product B-spline has observed data on its support. The methods are evaluated using simulated data and their predictive performance is compared with other competing scalar-on-function regression alternatives. We illustrate the usefulness of our approach through an application to brain tractography, where X(t) is a signal from diffusion tensor imaging at position, t, along a tract in the brain. In one example, the response is disease-status (case or control) and in a second example, it is the score on a cognitive test. R code for performing the simulations and fitting the FGAM can be found in supplemental materials available online.

  10. Chemical fingerprinting of petroleum biomarkers in biota samples using retention-time locking chromatography and multivariate analysis.

    PubMed

    Bartolomé, Luis; Deusto, Miren; Etxebarria, Nestor; Navarro, Patricia; Usobiaga, Aresatz; Zuloaga, Olatz

    2007-07-20

    This work was conducted to study a new separation and evaluation approach for the chemical fingerprinting of petroleum biomarkers in biota samples. The final aim of this work was to study the correlation between the observed effects in the shore habitats (mussels and limpets) and one pollution source: the oil spill of the Prestige tanker. The method combined a clean-up step of the biota extracts (mussels and limpets), the retention-time locking of the gas chromatographic set up, and the multivariate data analysis of the chromatograms. For clean-up, solid-phase extraction and gel permeation chromatography were compared, and 5g Florisil cartridges assured the lack of interfering compounds in the last extracts. In order to assure reproducible retention times and to avoid the realignment of the chromatograms, the retention-time locking feature of our gas chromatography-mass spectrometry (GC-MS) set up was used. Finally, in the case of multivariate analysis, the GC-MS chromatograms were treated, essentially by derivatization and by normalization, and all the chromatograms at m/z 191 (terpenes), m/z 217-218 (steranes and diasteranes) and m/z 231 (triaromatic steranes) were treated by means of principal component analysis. Furthermore, slightly different four oil samples from the Prestige oil spill were analyzed following the Nordtest method, and the GC-MS chromatograms were considered as the reference chemical fingerprints of the sources. In this sense, the correlation between the studied samples, including sediments and biota samples, and the source candidate was completed by means of a supervised pattern recognition method. As a result, the method proposed in this work was useful to identify the Prestige oil spill as the source of many of the analyzed samples.

  11. Analysis of thyreostatic drugs in thyroid samples by liquid chromatography tandem mass spectrometry: comparison of two sample treatment strategies.

    PubMed

    Abuín, S; Companyó, R; Centrich, F; Rúbies, A; Prat, M D

    2008-10-17

    A method based on ultra-performance liquid chromatography-electrospray ionisation-tandem mass spectrometry (UPLC-MS/MS) for the determination of six thyreostatic drugs in thyroid tissue has been optimised and validated in accordance with Decision 2002/657/EC. Sample extraction was evaluated in methanol and in ethyl acetate, the latter which gave better results. Two clean-up strategies were compared: one based on silica cartridges (SPE), and the other, on gel permeation chromatography (GPC). Recoveries ranged from 40% to 79% for the SPE approach and from 80% to 109% for GPC. Quantification was performed with blank tissue samples spiked with the analytes in the range 50-500microgkg(-1). 5,6-Dimethyl-2-thiouracil and 2-mercaptobenzimidazole-d(4) were used as internal standards. Decision limit (CCalpha) and detection capability (CCbeta) ranged from 1 to 15microgkg(-1) and from 6 to 25microgkg(-1), respectively. The accuracy of the method was calculated as percent error, which was less than 10%. The relative standard deviation in reproducibility conditions ranged between 2% and 14%.

  12. Analysis of thyreostatic drugs in thyroid samples by liquid chromatography tandem mass spectrometry: comparison of two sample treatment strategies.

    PubMed

    Abuín, S; Companyó, R; Centrich, F; Rúbies, A; Prat, M D

    2008-10-17

    A method based on ultra-performance liquid chromatography-electrospray ionisation-tandem mass spectrometry (UPLC-MS/MS) for the determination of six thyreostatic drugs in thyroid tissue has been optimised and validated in accordance with Decision 2002/657/EC. Sample extraction was evaluated in methanol and in ethyl acetate, the latter which gave better results. Two clean-up strategies were compared: one based on silica cartridges (SPE), and the other, on gel permeation chromatography (GPC). Recoveries ranged from 40% to 79% for the SPE approach and from 80% to 109% for GPC. Quantification was performed with blank tissue samples spiked with the analytes in the range 50-500microgkg(-1). 5,6-Dimethyl-2-thiouracil and 2-mercaptobenzimidazole-d(4) were used as internal standards. Decision limit (CCalpha) and detection capability (CCbeta) ranged from 1 to 15microgkg(-1) and from 6 to 25microgkg(-1), respectively. The accuracy of the method was calculated as percent error, which was less than 10%. The relative standard deviation in reproducibility conditions ranged between 2% and 14%. PMID:18768184

  13. Assessment of the value of reducing uncertainty by sampling in a groundwater remediation system.

    PubMed

    Ma, Hwong-wen; Chang, Chih-Chen

    2008-08-25

    The success of cleaning up a contaminated site depends on the degree of knowledge of the site's characteristics. When there is much uncertainty associated with the knowledge, the uncertainty regarding whether the remediation will work increases consequently. It is therefore essential to know how much reduction of uncertainty is needed for the purpose of designing a successful and reliable remediation system. The understanding of the site characteristics is basically increased by site investigation, and thus the uncertainty is decreased by sampling information. This study develops a method to evaluate the value of reducing uncertainty by sampling the hydrogeological parameters in a groundwater remediation system. Hydraulic conductivity being taken as an example of the site characteristics, random field generation and conditional simulation are coupled to obtain a range of hydraulic conductivity fields based on the sampling outputs. A multiple-realization management model that incorporates a chance constraint of health risk is used to find the lowest remediation cost under specific remediation criteria of risk through genetic algorithm. The remediation cost, which is expected to decrease with collection of more samples, serves as the measure of the value of uncertainty reduction by sampling. A case study shows that the variation of the hydraulic conductivity fields among the potential sites as well as the remediation cost is reduced as a result of increase of samples. It also shows that the risk after remediation decreases with the collection of more samples, which implies that the reduction of risk can also be used to assess the value of sampling.

  14. Determination of pesticide residues in honeybees using modified QUEChERS sample work-up and liquid chromatography-tandem mass spectrometry.

    PubMed

    Bargańska, Żaneta; Slebioda, Marek; Namieśnik, Jacek

    2014-01-01

    Increasing emissions of chemical compounds to the environment, especially of pesticides, is one of factors that may explain present honeybee colony losses. In this work, an analytical method employing liquid chromatography-tandem mass spectrometry (LC-MS/MS) was optimized for the simultaneous screening of 19 pesticides which have not been yet determined in honeybee samples from northern Poland (Pomerania). The sample preparation, based on the QuEChERS method combining salting-out liquid-liquid extraction to acetonitrile and a dispersive-SPE clean-up, was adjusted to honeybee samples by adding a small amount of hexane to eliminate beeswax. The recovery of analytes ranged from 70% to 120% with relative standard deviation ≤20%. The limits of detection were in the range of 0.91-25 ng/g. A total of 19 samples of honeybees from suspected pesticide poisoning incidents were analyzed, in which 19 different pesticides were determined.

  15. Multi-residue determination of 10 selected new psychoactive substances in wastewater samples by liquid chromatography-tandem mass spectrometry.

    PubMed

    Borova, Viola L; Gago-Ferrero, Pablo; Pistos, Constantinos; Thomaidis, Nikolaos S

    2015-11-01

    New psychoactive substances (NPSs) have become increasingly popular in recent years. The analysis of these substances in influent wastewater (IWW) can be used to track their use in communities. In addition, an evaluation of the amount of NPSs released to the aquatic environment can be performed through the analysis of effluent wastewater (EWW). This study presents the development, validation and application of an analytical methodology, based on solid phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS), for the determination of 10 NPSs in IWW and EWW. Synthetic cannabinoids, cathinones, piperazines and pyrrolidophenones are included among the target analytes. To the authors' knowledge, it is the first time that eight out of these substances (4'-methylpyrrolidinobutyrophenone (MPPP), a-pyrrolidinopentiophenone (a-PVP), 2-[(1S,3R)-3-hydroxycyclohexyl]-5-(2-methyl-2-octanyl) phenol (CP47,497), (1-naphthyl(1-pentyl-1H-indol-3-yl) methanone (JWH-018), (1-butyl-1H-indol-3-yl)(1-naphthyl) methanone (JWH-073), (4-ethyl-1-naphthyl)(1-pentyl-1H-indol-3-yl) methanone (JWH-210), (4-methyl-1-naphthyl) (1-pentyl-1H-indol-3-yl) methanone (JWH-122) and 2-(2-methoxyphenyl)-1-(1-pentyl-1H-indol-3-yl) ethanone (JWH-250)) are investigated in wastewater. The optimized conditions for the analysis of this set of compounds included a SPE clean-up step using a polymeric sorbent and the use of a pentafluorophenyl (PFP) chromatographic column. Despite the broad range of physicochemical properties of the analytes the method allowed acceptable absolute recoveries (40-109%) for all the studied compounds at different levels of concentration. Low method limits of detection (MLODs) were achieved, ranging between 0.3 and 10 ng/L except for BZP and CP47,497 (20 and 23 ng/L, respectively), allowing a reliable and accurate quantification of the analytes. The method was successfully applied to the analysis of IWW and EWW samples from five wastewater treatment plants

  16. Application of the SmartSampling Methodology to the Evaluation of Contaminated Landscape Soils at Brookhaven National Laboratory

    SciTech Connect

    RAUTMAN,CHRISTOPHER A.

    2000-08-01

    Portions of the SmartSampling{trademark} analysis methodology have been applied to the evaluation of radioactive contaminated landscape soils at Brookhaven National Laboratory. Specifically, the spatial, volumetric distribution of cesium-137 ({sup 137}Cs) contamination within Area of Concern 16E-1 has been modeled probabilistically using a geostatistical methodology, with the purpose of identifying the likelihood of successfully reducing, with respect to a pre-existing, baseline remediation plan, the volume of soil that must be disposed of offsite during clean-up. The principal objective of the analysis was to evaluate the likelihood of successful deployment of the Segmented Gate System (SGS), a novel remediation approach that emphasizes real-time separation of clean from contaminated materials during remediation operations. One primary requirement for successful application of the segmented gate technology investigated is that a variety of contaminant levels exist at the deployment site, which would enable to the SGS to discriminate material above and below a specified remediation threshold value. The results of this analysis indicate that there is potential for significant volume reduction with respect to the baseline remediation plan at a threshold excavation level of 23 pCi/g {sup 137}Cs. A reduction of approximately 50%, from a baseline volume of approximately 1,064.7 yd{sup 3} to less than 550 yd{sup 3}, is possible with acceptance of only a very small level of engineering risk. The vast majority of this volume reduction is obtained by not excavating almost all of levels 3 and 4 (from 12 to 24 inches in depth), which appear to be virtually uncontaminated, based on the available data. Additional volume reductions related to soil materials on levels 1 (depths of 0--6 inches) and 2 (6--12 inches) may be possible, specifically through use of the SGS technology. Level-by-level evaluation of simulation results suggests that as much as 26 percent of level 1 and as

  17. Deterministic multidimensional nonuniform gap sampling.

    PubMed

    Worley, Bradley; Powers, Robert

    2015-12-01

    Born from empirical observations in nonuniformly sampled multidimensional NMR data relating to gaps between sampled points, the Poisson-gap sampling method has enjoyed widespread use in biomolecular NMR. While the majority of nonuniform sampling schemes are fully randomly drawn from probability densities that vary over a Nyquist grid, the Poisson-gap scheme employs constrained random deviates to minimize the gaps between sampled grid points. We describe a deterministic gap sampling method, based on the average behavior of Poisson-gap sampling, which performs comparably to its random counterpart with the additional benefit of completely deterministic behavior. We also introduce a general algorithm for multidimensional nonuniform sampling based on a gap equation, and apply it to yield a deterministic sampling scheme that combines burst-mode sampling features with those of Poisson-gap schemes. Finally, we derive a relationship between stochastic gap equations and the expectation value of their sampling probability densities.

  18. Deterministic multidimensional nonuniform gap sampling

    NASA Astrophysics Data System (ADS)

    Worley, Bradley; Powers, Robert

    2015-12-01

    Born from empirical observations in nonuniformly sampled multidimensional NMR data relating to gaps between sampled points, the Poisson-gap sampling method has enjoyed widespread use in biomolecular NMR. While the majority of nonuniform sampling schemes are fully randomly drawn from probability densities that vary over a Nyquist grid, the Poisson-gap scheme employs constrained random deviates to minimize the gaps between sampled grid points. We describe a deterministic gap sampling method, based on the average behavior of Poisson-gap sampling, which performs comparably to its random counterpart with the additional benefit of completely deterministic behavior. We also introduce a general algorithm for multidimensional nonuniform sampling based on a gap equation, and apply it to yield a deterministic sampling scheme that combines burst-mode sampling features with those of Poisson-gap schemes. Finally, we derive a relationship between stochastic gap equations and the expectation value of their sampling probability densities.

  19. Performance Boosting Additive

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Mainstream Engineering Corporation was awarded Phase I and Phase II contracts from Goddard Space Flight Center's Small Business Innovation Research (SBIR) program in early 1990. With support from the SBIR program, Mainstream Engineering Corporation has developed a unique low cost additive, QwikBoost (TM), that increases the performance of air conditioners, heat pumps, refrigerators, and freezers. Because of the energy and environmental benefits of QwikBoost, Mainstream received the Tibbetts Award at a White House Ceremony on October 16, 1997. QwikBoost was introduced at the 1998 International Air Conditioning, Heating, and Refrigeration Exposition. QwikBoost is packaged in a handy 3-ounce can (pressurized with R-134a) and will be available for automotive air conditioning systems in summer 1998.

  20. Sewage sludge additive

    NASA Technical Reports Server (NTRS)

    Kalvinskas, J. J.; Mueller, W. A.; Ingham, J. D. (Inventor)

    1980-01-01

    The additive is for a raw sewage treatment process of the type where settling tanks are used for the purpose of permitting the suspended matter in the raw sewage to be settled as well as to permit adsorption of the dissolved contaminants in the water of the sewage. The sludge, which settles down to the bottom of the settling tank is extracted, pyrolyzed and activated to form activated carbon and ash which is mixed with the sewage prior to its introduction into the settling tank. The sludge does not provide all of the activated carbon and ash required for adequate treatment of the raw sewage. It is necessary to add carbon to the process and instead of expensive commercial carbon, coal is used to provide the carbon supplement.