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Sample records for imprinted solid-phase extraction

  1. Solid phase extraction of food contaminants using molecular imprinted polymers.

    PubMed

    Baggiani, Claudio; Anfossi, Laura; Giovannoli, Cristina

    2007-05-15

    Food contamination from natural or anthropogenic sources poses severe risks to human health. It is now largely accepted that continuous exposure to low doses of toxic chemicals can be related to several chronic diseases, including some type of cancer and serious hormonal dysfunctions. Contemporary analytical methods have the sensitivity required for contamination detection and quantification, but direct application of these methods on food samples can be rarely performed. In fact, the matrix introduces severe disturbances, and analysis can be performed only after some clean-up and preconcentration steps. Current sample pre-treatment methods, mostly based on the solid phase extraction technique, are very fast and inexpensive but show a lack of selectivity, while methods based on immunoaffinity extraction are very selective but expensive and not suitable for harsh environments. Thus, inexpensive, rapid and selective clean-up methods, relaying on "intelligent" materials are needed. Recent years have seen a significant increase of the "molecularly imprinted solid phase extraction" (MISPE) technique in the food contaminant analysis. In fact, this technique seems to be particularly suitable for extractive applications where analyte selectivity in the presence of very complex and structured matrices represents the main problem. In this review, several applications of MISPE in food contamination analysis will be discussed, with particular emphasis on the extraction of pesticides, drugs residua, mycotoxins and environmental contaminants. PMID:17456421

  2. Molecularly imprinted solid phase extraction of fluconazole from pharmaceutical formulations.

    PubMed

    Manzoor, S; Buffon, R; Rossi, A V

    2015-03-01

    This work encompasses a direct and coherent strategy to synthesise a molecularly imprinted polymer (MIP) capable of extracting fluconazole from its sample. The MIP was successfully prepared from methacrylic acid (functional monomer), ethyleneglycoldimethacrylate (crosslinker) and acetonitrile (porogenic solvent) in the presence of fluconazole as the template molecule through a non-covalent approach. The non-imprinted polymer (NIP) was prepared following the same synthetic scheme, but in the absence of the template. The data obtained from scanning electronic microscopy, infrared spectroscopy, thermogravimetric and nitrogen Brunauer-Emmett-Teller plot helped to elucidate the structural as well as the morphological characteristics of the MIP and NIP. The application of MIP as a sorbent was demonstrated by packing it in solid phase extraction cartridges to extract fluconazole from commercial capsule samples through an offline analytical procedure. The quantification of fluconazole was accomplished through UPLC-MS, which resulted in LOD≤1.63×10(-10) mM. Furthermore, a high percentage recovery of 91±10% (n=9) was obtained. The ability of the MIP for selective recognition of fluconazole was evaluated by comparison with the structural analogues, miconazole, tioconazole and secnidazole, resulting in percentage recoveries of 51, 35 and 32%, respectively. PMID:25618633

  3. Synthesis and application of cephalexin imprinted polymer for solid phase extraction in milk.

    PubMed

    Lata, Kiran; Sharma, Rajan; Naik, Laxmana; Rajput, Y S; Mann, Bimlesh

    2015-10-01

    Molecular imprinted polymer (MIP) against cephalexin was synthesized by co-polymerization of functional monomer, cross-linker, radical initiator, along with target molecule (cephalexin) in a porogenic material. Binding of cephalexin towards prepared MIP was studied in different solvents (water, methanol, 1M NaCl, acetone and acetonitrile) and best binding was observed in methanol. Partition coefficient and selectivity of prepared imprint and non-imprint was also studied. Cross reactivity in terms of binding efficiency was also assessed with other antibiotics. Chromatographic study of MIP was carried out by packing prepared imprint into glass column. MIP was used as matrix in solid phase extraction (SPE) for recovery of cephalexin from spiked milk samples for further estimation by high performance liquid chromatography. No interference was observed from milk components after elution of cephalexin from MIP, indicating selectivity and affinity of MIP. On the other hand, interference was observed in eluate obtained from C18 SPE column. PMID:25872441

  4. Molecularly imprinted polymer microspheres for solid-phase extraction of protocatechuic acid in Rhizoma homalomenae.

    PubMed

    Chen, Fang-Fang; Wang, Guo-Ying; Shi, Yan-Ping

    2011-10-01

    Molecularly imprinted polymers (MIPs) had been prepared by precipitation polymerization method using acrylamide as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, acetonitrile as the porogen solvent and protocatechuic acid (PA), one of phenolic acids, as the template molecule. The MIPs were characterized by scanning electron microscopy and Fourier transform infrared, and their performance relative to non-imprinted polymers was assessed by equilibrium binding experiments. Six structurally similar phenolic acids, including p-hydroxybenzoic acid, gallic acid, salicylic acid, syringic acid, vanillic acid, ferulic acid were selected to assess the selectivity and recognition capability of the MIPs. The MIPs were applied to extract PA from the traditional Chinese medicines as a solid-phase extraction sorbent. The resultant cartridge showed that the MIPs have a good extraction performance and were able to selectively extract almost 82% of PA from the extract of Rhizoma homalomenae. Thus, the proposed molecularly imprinted-solid phase extraction-high performance liquid chromatography method can be successfully used to extract and analyse PA in traditional Chinese medicines. PMID:21809445

  5. Molecularly imprinted polymer solid-phase extraction for detection of zearalenone in cereal sample extracts.

    PubMed

    Lucci, Paolo; Derrien, Delphine; Alix, Florent; Pérollier, Céline; Bayoudh, Sami

    2010-07-01

    The aim of this work was to develop a method for the clean-up and preconcentration of zearalenone from corn and wheat samples employing molecularly imprinted polymer (MIP) as selective sorbent for solid-phase extraction (SPE). Cereal samples were extracted with acetonitrile/water (75:25, v/v) and the extract was diluted with water and applied to an AFFINIMIP ZON MIP-SPE column. The column was then washed to eliminate the interferences and zearalenone was eluted with methanol and quantified using HPLC with fluorescence detection (lambda(exc)=275/lambda(em)=450 nm). The precision and accuracy of the method were satisfactory for both cereals at the different fortification levels tested and it gave recoveries between 82 and 87% (RSDr 2.5-6.2%, n=3) and 86 and 90% (RSDr 0.9-6.8%, n=3) for wheat and maize, respectively. MIP-SPE column capacity was determined to be not less than 6.6 microg of zearalenone and to be at least four times higher than that of immunoaffinity column (IAC). The application of AFFINIMIP ZON molecularly imprinted polymer as a selective sorbent material for detection of zearalenone fulfilled the method performance criteria required by the Commission Regulation (EC) No. 401/2006, demonstrating the suitability of the technique for the control of zearalenone in cereal samples. PMID:20579483

  6. Molecularly imprinted hollow spheres for the solid phase extraction of estrogens.

    PubMed

    Chen, Wei; Xue, Min; Xue, Fei; Mu, Xiangrong; Xu, Zhibin; Meng, Zihui; Zhu, Guangxian; Shea, Kenneth J

    2015-08-01

    Solid phase extraction (SPE) is widely used in many different areas, such as environmental, biological, and food analysis, where cleaning and pre-concentration of samples are key steps in the analytical protocol. New materials have significant impact on the development of solid phase extraction. In this paper, mono-dispersed molecularly imprinted hollow spheres (MIHSs) of β-estradiol (E2) were synthesized using silica nanospheres particles as the sacrificial matrix. Compared to the corresponding non-imprinted hollow spheres (NIHSs), the MIHSs with uniform size of 290 nm have outstanding affinity in aqueous solution. Static saturation adsorption required only 15min to achieve equilibrium, with a binding capacity (Qmax) of 44.5 μmol g(-1). The extraction of E2, ethinyl estradiol (EE), diethylstilbestrol (DES), ethisterone (ES) and estrone (E1) from water samples by MIHSs was also investigated. In the spiked samples of tap water, Qinghe river water and Zhanjiang river water, more than 90.42% of E2, but less than 79% of EE, DES, ES and E1 were recovered. The limits of detection (LOD) ranged from 0.1 to 0.26 µmol L(-1) after solid phase extraction by MIHSs and HPLC-UV analysis. The adsorption capacity of the MIHSs showed no significant deterioration after six rounds of regeneration. PMID:26048825

  7. Selective extraction of triazine herbicides based on a combination of membrane assisted solvent extraction and molecularly imprinted solid phase extraction.

    PubMed

    Chimuka, Luke; van Pinxteren, Manuela; Billing, Johan; Yilmaz, Ecevit; Jönsson, Jan Åke

    2011-02-01

    A selective extraction technique based on the combination of membrane assisted solvent extraction and molecularly imprinted solid phase extraction for triazine herbicides in food samples was developed. Simazine, atrazine, prometon, terbumeton, terbuthylazine and prometryn were extracted from aqueous food samples into a hydrophobic polypropylene membrane bag containing 1000μL of toluene as the acceptor phase along with 100mg of MIP particles. In the acceptor phase, the compounds were re-extracted onto MIP particles. The extraction technique was optimised for the type of organic acceptor solvent, amount of molecularly imprinted polymers particles in the organic acceptor phase, extraction time and addition of salt. Toluene as the acceptor phase was found to give higher triazine binding onto MIP particles compared to hexane and cyclohexane. Extraction time of 120min and 100mg of MIP were found to be optimum parameters. Addition of salt increased the extraction efficiency for more polar triazines. The selectivity of the technique was demonstrated by extracting spiked cow pea and corn extracts where clean chromatograms were obtained compared to only membrane assisted solvent extraction or only molecularly imprinted solid phase extraction. The study revealed that this combination may be a simple way of selectively extracting compounds in complex samples. PMID:21190688

  8. Water-compatible molecularly imprinted polymers for selective solid phase extraction of dencichine from the aqueous extract of Panax notoginseng.

    PubMed

    Ji, Wenhua; Xie, Hongkai; Zhou, Jie; Wang, Xiao; Ma, Xiuli; Huang, Luqi

    2016-01-01

    Specific molecularly imprinted polymers for dencichine were developed for the first time in this study by the bulk polymerization using phenylpyruvic acid and dl-tyrosine as multi-templates. The photographs confirmed that molecularly imprinted polymers prepared using N,N'-methylene diacrylamide as cross-linker and glycol dimethyl ether as porogen displayed excellent hydrophilicity. Selectivity, adsorption isotherm and adsorption kinetics were investigated. The sample loading-washing-eluting solvent was optimized to evaluate the property of molecularly imprinted solid phase extract. Compared with LC/WCX-SPE, water-compatible molecularly imprinted solid phase extraction displayed more excellent specific adsorption performance. The extracted dencichine from Panax notoginseng with the purity of 98.5% and the average recovery of 85.6% (n=3) was obtained. PMID:26680322

  9. Sequential molecularly imprinted solid-phase extraction methods for the analysis of resveratrol and other polyphenols.

    PubMed

    Schwarz, Lachlan J; Danylec, Basil; Harris, Simon J; Boysen, Reinhard I; Hearn, Milton T W

    2016-03-18

    Molecularly imprinted polymers (MIPs) templated with either the phytoalexin, (E)-resveratrol, or its structural analog, 3,5-dihydroxy-N-(4-hydroxyphenyl)benzamide, have been used in tandem for the sequential extraction of (E)-resveratrol from aqueous peanut meal extracts in high purity and in near quantitative yields. Re-processing of the (E)-resveratrol-depleted peanut meal extract with the 3,5-dihydroxy-N-(4-hydroxyphenyl)benzamide imprinted MIP yielded additional polyphenolic components, identified as A-type procyanidins. Tandem liquid chromatography-electrospray ionization mass spectrometry confirmed the identity and purity of the isolated products. This study documents the advantages of tandem approaches with MIPs for the solid phase extraction and analysis of multiple bioactive compounds present in complex biomass waste streams. PMID:26905880

  10. Dummy molecularly imprinted mesoporous silica prepared by hybrid imprinting method for solid-phase extraction of bisphenol A.

    PubMed

    Yu, Dan; Hu, Xiaolei; Wei, Shoutai; Wang, Qiang; He, Chiyang; Liu, Shaorong

    2015-05-29

    A novel hybrid dummy imprinting strategy was developed to prepare a mesoporous silica for the solid-phase extraction (SPE) of bisphenol A (BPA). A new covalent template-monomer complex (BPAF-Si) was first synthesized with 2,2-bis(4-hydroxyphenyl)hexafluoropropane (BPAF) as the template. The imprinted silica was obtained through the gelation of BPAF-Si with tetraethoxysilane and the subsequent removal of template by thermal cleavage, and then it was characterized by FT-IR spectroscopy, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption-desorption isotherms. Results showed that the new silica had micron-level particle size and ordered mesoporous structure. The static binding test verified that the imprinted silica had much higher recognition ability for BPA than the non-imprinted silica. The imprinted silica also showed high extraction efficiencies and high enrichment factor for SPE of BPA. Using the imprinted silica, a SPE-HPLC-UV method was developed and successfully applied for detecting BPA in BPA-spiked tap water and lake water samples with a recovery of 99-105%, a RSD of 2.7-5.0% and a limit of detection (S/N=3) of 0.3ng/mL. The new imprinted silica avoided the interference of the residual template molecules and reduced the non-specific binding sites, and therefore it can be utilized as a good sorbent for SPE of BPA in environmental water samples. PMID:25892637

  11. Development of andrographolide molecularly imprinted polymer for solid-phase extraction

    NASA Astrophysics Data System (ADS)

    Yin, Xiaoying; Liu, Qingshan; Jiang, Yifan; Luo, Yongming

    2011-06-01

    A method employing molecularly imprinted polymer (MIP) as selective sorbent for solid-phase extraction (SPE) to pretreat samples was developed. The polymers were prepared by precipitation polymerization with andrographolide as template molecule. The structure of MIP was characterized and its static adsorption capacity was measured by the Scatchard equation. In comparison with C 18-SPE and non-imprinted polymer (NIP) SPE column, MIP-SPE column displays high selectivity and good affinity for andrographolide and dehydroandrographolide for extract of herb Andrographis paniculata ( Burm.f.) Nees (APN). MIP-SPE column capacity was 11.9 ± 0.6 μmol/g and 12.1 ± 0.5 μmol/g for andrographolide and dehydroandrographolide, respectively and was 2-3 times higher than that of other two columns. The precision and accuracy of the method developed were satisfactory with recoveries between 96.4% and 103.8% (RSD 3.1-4.3%, n = 5) and 96.0% and 104.2% (RSD 2.9-3.7%, n = 5) for andrographolide and dehydroandrographolide, respectively. Various real samples were employed to confirm the feasibility of method. This developed method demonstrates the potential of molecularly imprinted solid phase extraction for rapid, selective, and effective sample pretreatment.

  12. Development of a molecularly imprinted solid-phase extraction sorbent for the selective extraction of telmisartan from human urine.

    PubMed

    Yılmaz, Hüma; Basan, Hasan

    2015-05-01

    A novel molecularly imprinted solid-phase extraction with spectrofluorimetry method has been developed for the selective extraction of telmisartan from human urine. Molecularly imprinted polymers were prepared by a noncovalent imprinting approach through UV-radical polymerization using telmisartan as a template molecule, 2-dimethylamino ethyl methacrylate as a functional monomer, ethylene glycol dimethacrylate as a cross-linker, N,N-azobisisobutyronitrile as an initiator, chloroform as a porogen. Molecularly imprinted polymers and nonimprinted control polymer sorbents were dry-packed into solid-phase extraction cartridges, and eluates from cartridges were analyzed using a spectrofluorimeter. Limit of detection and limit of quantitation values were 11.0 and 36.0 ng/mL, respectively. A very high imprinting factor (16.1) was achieved and recovery values for the telmisartan spiked in human urine were in the range of 76.1-79.1%. In addition, relatively low within-day (0.14-1.6%) and between-day (0.11-1.31%) precision values were obtained. Valsartan was used to evaluate the selectivity of sorbent as well. As a result, a sensitive, selective, and simple molecularly imprinted solid-phase extraction with spectrofluorimetry method has been developed and successfully applied to the direct determination telmisartan in human urine. PMID:25755138

  13. Molecularly imprinted polymers-curcuminoids and its application for solid phase extraction

    NASA Astrophysics Data System (ADS)

    Wulandari, Meyliana; Amran, M. B.; Lopez, A. B. Descalzo; Urraca, J. L.; Moreno-Bondi, M. C.

    2014-03-01

    Molecularly Imprinted Polymers (MIPs) for the selective recognition properties of curcumin (CUR), a cancer chemopreventive agent were obtained by a non-covalent imprinting approach with bisdemetoxycurcumin (BDMC) as the template molecule. The double bond of BDMC has been reduced in order not to be involved in polymerization and make the template molecules easy to be eluted. Several functional monomers have been evaluated to maximize the interactions with the template molecule during polymerization. MIPs prepared by bulk of N-(2-aminoethyl) metacrylamid hydrochlorideas functional monomer, ethylene glycol dimethacrylate as crosslinker, 2,2'-azobis (2'4-dimethyl valeronitril) as initiator and acetonitrile as porogen. Non-imprinted polymer (NIP) have been also synthesized for reference purposes. UV-vis spectroscopy has been used to predict the template to functional monomer ratio which indicates the formation of 2:1 complexes between monomer and curcumin and the association constants (K11 = 2529 μM and K12 = 1960.75 μM in acetonitrile). The capacity and imprinting factor have been evaluated as stationary phases in high-pressure liquid chromatography to CUR and BDMC. The binding properties and the homogeneity of the binding sites of the different polymers have been studied by Freundlich isotherm modeling and weight average affinity and number of binding sites. One of the foremost applications of molecular imprinting has been in molecularly imprinted solid phase extraction and it has the ability to separate and preconcentrate between closely related compounds in curcuminoids.

  14. Determination of cyproheptadine in feeds using molecularly imprinted solid-phase extraction coupled with HPLC.

    PubMed

    Yang, Jianwen; Wang, Zongnan; Zhou, Tong; Song, Xuqin; Liu, Qingyong; Zhang, Yuman; He, Limin

    2015-05-15

    A novel method was developed for the determination of cyproheptadine in feeds using molecularly imprinted solid-phase extraction coupled with high-performance liquid chromatography. The polymers were prepared using cyproheptadine as a template molecule, methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a cross-linking agent, and dichloromethane as a solvent by bulk polymerization. Under the optimum solid-phase extraction conditions, the molecular imprinting cartridge can selectively extract and enrich cyproheptadine from a variety of feeds. Mean recoveries of cyproheptadine from four kinds of feeds spiked at 0.1, 1.0 and 10mgkg(-1) ranged from 85.5% to 96.2%, with intra-day and inter-day relative standard deviation less than 10%. The calibration curve of cyproheptadine was good linear relationship (r>0.9993) within the range of 0.1-50μgmL(-1). The limit of detection (LOD) and the limit of quantification (LOQ) were 0.04 and 0.1mgkg(-1), respectively. PMID:25855316

  15. Molecularly imprinted polymer grafted to porous polyethylene frits: a new selective solid-phase extraction format.

    PubMed

    Barahona, Francisco; Turiel, Esther; Martín-Esteban, Antonio

    2011-10-01

    In this paper, a novel format for selective solid-phase extraction based on a molecularly imprinted polymer (MIP) is described. A small amount of MIP has been synthesized within the pores of commercial polyethylene (PE) frits and attached to its surface using benzophenone (BP), a photo-initiator capable to start the polymerisation from the surface of the support material. Key properties affecting the obtainment of a proper polymeric layer, such as polymerisation time and kind of cross-linker were optimised. The developed imprinted material has been applied as a selective sorbent for cleaning extracts of thiabendazole (TBZ), as model compound, from citrus samples. The use of different solvents for loading the analyte in the imprinted frits was investigated, as well as the binding capacity of the imprinted polymer. Imprinted frits showed good selectivity when loads were performed using toluene and a linear relationship was obtained for the target analyte up to 1000 ng of loaded analyte. Prepared composite material was applied to the SPE of TBZ in real samples extracts, showing an impressive clean-up ability. Calibrations showed good linearity in the concentration range of 0.05-5.00 μg g(-1), referred to the original solid sample, and the regression coefficients obtained were greater than 0.996. The calculated detection limit was 0.016 μg g(-1), low enough to satisfactory analysis of TBZ in real samples. RSDs at different spiking levels ranged below 15% in all the cases and imprinted frits were reusable without loss in their performance. PMID:21855075

  16. Molecularly imprinted solid-phase extraction for the determination of fenitrothion in tomatoes.

    PubMed

    Pereira, Leandro Alves; Rath, Susanne

    2009-02-01

    Organophosphorus insecticides are widely employed in agriculture, and residues of them can remain after harvesting or storage. Pesticide residue control is an important task for ensuring food safety. Common chromatographic methods used in the determination of pesticide residues in food require clean-up and concentration steps prior to quantitation. While solid-phase extraction has been widely employed for this purpose, there is a need to improve selectivity. Due to their inherent biomimetic recognition systems, molecularly imprinted polymers (MIP) allow selectivity to be enhanced while keeping the costs of analysis low. In this work, a MIP that was designed to enable the selective extraction of fenitrothion (FNT) from tomatoes was synthesized using a noncovalent imprinting approach. The polymer was prepared using methacrylic acid as functional monomer and ethyleneglycol dimethacrylate as crosslinking monomer in dichloromethane (a porogenic solvent). The polymer was characterized by Fourier transform infrared spectroscopy, solid-state nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), and nitrogen sorption porosimetry. The pore structure and the surface area were evaluated using the BET adsorption method. To characterize the batch rebinding behavior of the MIP, the adsorption isotherm was measured, allowing the total number of binding sites, the average binding affinity and the heterogeneity index to be established. A voltammetric method of quantifying FNT during the molecularly imprinted solid-phase extraction (MISPE) studies was developed. The polymer was placed in extraction cartridges which were then used to clean up and concentrate FNT in tomato samples prior to high-performance liquid chromatographic quantitation. The material presented a medium extraction efficiency of 59% (for analyses performed with three different cartridges on three days and a fortification level of 5.0 microg g(-1)) and selectivity when used in the preparation of

  17. Determination of theophylline in serum by molecularly imprinted solid-phase extraction with pulsed elution.

    PubMed

    Mullett, W M; Lai, E P

    1998-09-01

    The technique of molecular imprinting is used to produce an extensively cross-linked poly(methacrylic acid-co-ethylene dimethacrylate) material that contains theophylline as a print molecule. After Soxhlet extraction of the theophylline, binding sites are formed in the polymer with complementary size, shape, and positioning of chemical functionalities. The molecularly imprinted polymer's (MIP) high theophylline selectivity, chemical stability, and physically robust nature make it an ideal stationary-phase material in columns for HPLC separation of theophylline from other structurally related drug compounds. Mobile-phase tests confirm that a retention mechanism typical of normal-phase chromatography governs the separation, and selectivity of the MIP column can be controlled by a combination of the mobile phase and the sample solvent. Under optimal conditions, the MIP column functions like a solid-phase sorbent for theophylline extraction. Rapid elution of the bound theophylline can be accomplished in a pulsed format through injection of 20 μL of a solvent that has the proper polarity and protic nature to disrupt the electrostatic interactions and hydrogen bonding between theophylline and binding sites. A concentration detection limit of 120 ng/mL is obtained using direct UV absorption detection at 270 nm, which corresponds to a mass detection limit of 2.4 ng. This new technique, molecularly imprinted solid-phase extraction with pulsed elution (MISPE-PE), permits on-line preconcentration of theophylline from a large volume of dilute sample solution. Using a sample volume of 300 μL, a 40 ng/mL standard solution produces a detectable peak signal. Application of MISPE-PE in serum analysis further demonstrates the high capability of the MIP column to selectively isolate theophylline from other matrix components for fast, accurate determination. PMID:21644709

  18. Synthesis of chitosan molecularly imprinted polymers for solid-phase extraction of methandrostenolone.

    PubMed

    Wang, Yun; Wang, Enlan; Wu, Ziming; Li, Huan; Zhu, Zhi; Zhu, Xinsheng; Dong, Ying

    2014-01-30

    Chitosan molecularly imprinted polymers (CHI-MIPs) for selective extraction of methandrostenolone (MA) was synthesized by cross-linking of chitosan with epichlorohydrin in the presence of MA as the template molecule. Systematic investigations of the influences of template, functional polymer, cross-linker as well as porogen concentrations on the rebinding capacity of CHI-MIPs were carried out. Adsorption and kinetic binding experiments indicated that the synthesized CHI-MIPs had high adsorption and excellent affinity to MA. Solid-phase extraction (SPE) using the prepared CHI-MIPs as adsorbent was then investigated, and the optimum loading and eluting conditions for SPE of the MA were established. The optimized SPE procedure was used to extract the MA from several spiked samples and a good sample clean-up was obtained with the average recoveries ranged from 95.97 to 101.79%. PMID:24299807

  19. Extraction of quercetin from Herba Lysimachiae by molecularly imprinted-matrix solid phase dispersion.

    PubMed

    Hong, Yansuo; Chen, Ligang

    2013-12-15

    A new kind of quercetin molecularly imprinted polymer (MIP) was synthesized and applied as a selective sorbent in matrix solid-phase dispersion (MSPD) for the extraction of quercetin in Herba Lysimachiae. The MIP was prepared by surface imprinting method using quercetin as template, methacrylic acid as functional monomer, trimethylolpropane trimethacrylate as crosslinker and methanol as porogen. The selectivity of quercetin MIP was evaluated according to their recognition to quercetin and a compound with similar molecular size (bergenin). Good binding for quercetin was observed in MIP adsorption experiment. The isothermal adsorption and dynamic adsorption experiments were also carried out in this study. The best quercetin extraction conditions were as follows: the ratio of MIP to sample was 1:1, the dispersion time was 10min, washing solvent was 2% aqueous methanol and elution solvent was acetic acid-methanol (2:98, v/v). The proposed method was compared with the method used in Chinese pharmacopeia. The similar extraction yield was obtained by the two methods. Moreover, this method is faster, simpler and can realize extraction and purification procedures in the same system. PMID:24184834

  20. Applications of magnetic surface imprinted materials for solid phase extraction of levofloxacin in serum samples.

    PubMed

    Xiao, Deli; Wang, Cuixia; Dai, Hao; Peng, Jun; He, Jia; Zhang, Kai; Kong, Sumei; Qiu, Panzi; He, Hua

    2015-05-01

    In this work, molecularly imprinted magnetic carbon nanotubes (MCNTs@MIPs) was prepared with surface imprinting technique for extraction of levofloxacin in serum samples. The preparation of molecularly imprinted polymers (MIPs) used levofloxacin as template, methacrylic acid as functional monomer, and ethylene glycol dimethacrylate as cross-linker, and the magnetic carbon nanotubes (MCNTs) was synthesized by solvothermal method. The prepared polymers not only can be separated and collected easily by an external magnetic, but also exhibited high specific surface area and high selectivity to template molecules. Kinetic adsorption and static adsorption capacity investigations indicated that the synthesized MCNTs@MIPs had excellent recognition towards levofloxacin. Furthermore, magnetic solid phase extraction (MSPE) using the prepared MCNTs@MIPs as sorbent was then investigated, and an efficient sample cleanup was obtained with recoveries ranged from 78.7 ± 4.8 % to 83.4 ± 4.1%. In addition, several parameters, including the pH of samples, the amount of MCNTs@MIPs, the adsorption and desorption times, and the eluent, were investigated to obtain optimal extraction efficiency. Under the optimal extraction conditions, the stability of the polymer was also evaluated, and the average recovery reduced less than 7.6% after 5 cycles. MCNTs@MIPs successfully applied in the preconcentration and determination of levofloxacin in serum sample suggested that the MSPE method based on the novel polymers could be a promising alternative for selective and efficient extraction of trace amounts of pharmaceutical substances in bio-matrix samples. PMID:25732346

  1. Comparison of molecularly imprinted solid-phase extraction (MISPE) with classical solid-phase extraction (SPE) for the detection of benzodiazepines in post-mortem hair samples.

    PubMed

    Anderson, Robert A; Ariffin, Marinah M; Cormack, Peter A G; Miller, Eleanor I

    2008-01-15

    This preliminary study compares the benzodiazepine results for 10 post-mortem scalp hair samples using a classical solid-phase extraction (SPE) and a molecularly imprinted solid-phase extraction (MISPE) system. The hair samples selected for testing were from drug-related deaths where a positive benzodiazepine blood result was obtained. Samples were decontaminated with 0.1% sodium dodecyl sulfate, distilled water and dichloromethane, incubated overnight in methanol/25% aqueous ammonium hydroxide (20:1), extracted by SPE or MISPE and subsequently analysed by liquid chromatography-tandem mass spectrometry (LC-MS-MS). Both extraction methods detected diazepam, nordiazepam, oxazepam, temazepam and nitrazepam in the samples. Diazepam was detected in a greater number of samples using MISPE due to both its lower limit of detection (LOD) and higher extraction recovery as a result of excellent molecular recognition of the template (diazepam) imparted by the imprinting process. The selective recognition of two diazepam analogues, nordiazepam and oxazepam, was demonstrated using MISPE since they were also detected in a greater number of samples. In contrast, another diazepam analogue, temazepam, was detected in a greater number of samples using SPE since the LOD using this extraction was lower than with MISPE. Nitrazepam was detected in one sample using both extraction methods. Overall the MISPE and SPE hair results were in good qualitative agreement. For the samples, where both extraction methods detected nordiazepam, temazepam and oxazepam, the concentrations were always higher for SPE. This is probably due to the MIP procedure producing extracts with fewer matrix interferences than the extracts produced using the classical SPE method. MISPE could be used as a complementary method to classical SPE for the analysis of benzodiazepine positive hair samples collected from chronic users. PMID:17467213

  2. Molecular imprinted polymer for solid-phase extraction of flavonol aglycones from Moringa oleifera extracts.

    PubMed

    Pakade, Vusumzi; Cukrowska, Ewa; Lindahl, Sofia; Turner, Charlotta; Chimuka, Luke

    2013-02-01

    Molecular imprinted polymer produced using quercetin as the imprinting compound was applied for the extraction of flavonol aglycones (quercetin and kaempferol) from Moringa oleifera methanolic extracts obtained using heated reflux extraction method. Identification and quantification of these flavonols in the Moringa extracts was achieved using high performance liquid chromatography with ultra violet detection. Breakthrough volume and retention capacity of molecular imprinted polymer SPE was investigated using a mixture of myricetin, quercetin and kaempferol. The calculated theoretical number of plates was found to be 14, 50 and 8 for myricetin, quercetin and kaempferol, respectively. Calculated adsorption capacities were 2.0, 3.4 and 3.7 μmol/g for myricetin, quercetin and kaempferol, respectively. No myricetin was observed in Moringa methanol extracts. Recoveries of quercetin and kaempferol from Moringa methanol extracts of leaves and flowers ranged from 77 to 85% and 75 to 86%, respectively, demonstrating the feasibility of using the developed molecularly imprinted SPE method for quantitative clean-up of both of these flavonoids. Using heated reflux extraction combined with molecularly imprinted SPE, quercetin concentrations of 975 ± 58 and 845 ± 32 mg/kg were determined in Moringa leaves and flowers, respectively. However, the concentrations of kaempferol found in leaves and flowers were 2100 ± 176 and 2802 ± 157 mg/kg, respectively. PMID:23255435

  3. Experimental and computational studies on molecularly imprinted solid-phase extraction for gonyautoxins 2,3 from dinoflagellate Alexandrium minutum.

    PubMed

    Lian, Ziru; Li, Hai-Bei; Wang, Jiangtao

    2016-08-01

    An innovative and effective extraction procedure based on molecularly imprinted solid-phase extraction (MISPE) was developed for the isolation of gonyautoxins 2,3 (GTX2,3) from Alexandrium minutum sample. Molecularly imprinted polymer microspheres were prepared by suspension polymerization and and were employed as sorbents for the solid-phase extraction of GTX2,3. An off-line MISPE protocol was optimized. Subsequently, the extract samples from A. minutum were analyzed. The results showed that the interference matrices in the extract were obviously cleaned up by MISPE procedures. This outcome enabled the direct extraction of GTX2,3 in A. minutum samples with extraction efficiency as high as 83 %, rather significantly, without any need for a cleanup step prior to the extraction. Furthermore, computational approach also provided direct evidences of the high selective isolation of GTX2,3 from the microalgal extracts. PMID:27251197

  4. Molecularly imprinted solid-phase extraction of glutathione from urine samples.

    PubMed

    Song, Renyuan; Hu, Xiaoling; Guan, Ping; Li, Ji; Zhao, Na; Wang, Qiaoli

    2014-11-01

    Molecularly imprinted polymer (MIP) particles for glutathione were synthesized through iniferter-controlled living radical precipitation polymerization (IRPP) under ultraviolet radiation at ambient temperature. Static adsorption, solid-phase extraction, and high-performance liquid chromatography were carried out to evaluate the adsorption properties and selective recognition characteristics of the polymers for glutathione and its structural analogs. The obtained IRPP-MIP particles exhibited a regularly spherical shape, rapid binding kinetics, high imprinting factor, and high selectivity compared with the MIP particles prepared using traditional free-radical precipitation polymerization. The selective separation and enrichment of glutathione from the mixture of glycyl-glycine and glutathione disulfide could be achieved on the IRPP-MIP cartridge. The recoveries of glutathione, glycyl-glycine, and glutathione disulfide were 95.6% ± 3.65%, 29.5% ± 1.26%, and 49.9% ± 1.71%, respectively. The detection limit (S/N=3) of glutathione was 0.5 mg·L(-1). The relative standard deviations (RSDs) for 10 replicate detections of 50 mg·L(-1) of glutathione were 5.76%, and the linear range of the calibration curve was 0.5 mg·L(-1) to 200 mg·L(-1) under optimized conditions. The proposed approach was successfully applied to determine glutathione in spiked human urine samples with recoveries of 90.24% to 96.20% and RSDs of 0.48% to 5.67%. PMID:25280681

  5. Novel restricted access materials combined to molecularly imprinted polymers for selective solid-phase extraction of organophosphorus pesticides from honey.

    PubMed

    He, Juan; Song, Lixin; Chen, Si; Li, Yuanyuan; Wei, Hongliang; Zhao, Dongxin; Gu, Keren; Zhang, Shusheng

    2015-11-15

    A novel restricted access materials (RAM) combined to molecularly imprinted polymers (MIPs), using malathion as template molecule and glycidilmethacrylate (GMA) as pro-hydrophilic co-monomer, were prepared for the first time. RAM-MIPs with hydrophilic external layer were characterized by scanning electron microscopy and recognition and selectivity properties were compared with the restricted access materials-non-molecularly imprinted polymers (RAM-NIPs) and unmodified MIPs. RAM-MIPs were used as the adsorbent enclosed in solid phase extraction column and several important extraction parameters were comprehensively optimized to evaluate the extraction performance. Under the optimum extraction conditions, RAM-MIPs exhibited comparable or even higher selectivity with greater extraction capacity toward six kinds of organophosphorus pesticides (including malathion, ethoprophos, phorate, terbufos, dimethoate, and fenamiphos) compared with the MIPs and commercial solid phase extraction columns. The RAM-MIPs solid phase extraction coupled with gas chromatography was successfully applied to simultaneously determine six kinds of organophosphorus pesticides from honey sample. The new established method showed good linearity in the range of 0.01-1.0 μg mL(-1), low limits of detection (0.0005-0.0019 μg mL(-1)), acceptable reproducibility (RSD, 2.26-4.81%, n = 6), and satisfactory relative recoveries (90.9-97.6%). It was demonstrated that RAM-MIPs solid phase extraction with excellent selectivity and restricted access function was a simple, rapid, selective, and effective sample pretreatment method. PMID:25977034

  6. Determination of sulfadiazine in eggs using molecularly imprinted solid-phase extraction coupled with high-performance liquid chromatography.

    PubMed

    He, Xiuping; Tan, Liju; Wu, Wei; Wang, Jiangtao

    2016-06-01

    The development of a simple and effective method for the isolation and purification of sulfadiazine residues in food of animal origin is of great significance since it is a great danger to human health. An off-line molecularly imprinted solid-phase extraction with high-performance liquid chromatography method was proposed for the selective pretreatment and determination of sulfadiazine in eggs, rapidly and effectively. The molecularly imprinted polymer was proved to have a homogeneous spherical structure and porous surface morphology with excellent adsorption capacity of 5258 μg/g for sulfadiazine. The newly established method showed a good linearity in the range of 0-200 μg/L, low limits of detection (0.06 μg/L), acceptable reproducibility (RSD, 2.60-5.03%, n = 3), and satisfactory relative recoveries (78.22-86.10%). It was demonstrated that the proposed molecularly imprinted solid-phase extraction with high-performance liquid chromatography method could be applied to determine sulfadiazine in eggs, which simplified the pretreatment procedure and improved the accuracy of the analysis process by reducing the loss of sulfadiazine in the fat-removing procedure compared with traditional methods. Molecularly imprinted solid-phase extraction with excellent selectivity and adsorption capacity is a simple, rapid, selective, and effective pretreatment method for the determination of sulfadiazine in egg samples. PMID:27063936

  7. Surface molecularly imprinted silica for selective solid-phase extraction of biochanin A, daidzein and genistein from urine samples.

    PubMed

    Chrzanowska, Anna M; Poliwoda, Anna; Wieczorek, Piotr P

    2015-05-01

    Selective molecularly imprinted silica polymer (SiO2MIP) for extraction of biochanin A, daidzein and genistein was synthesized using the surface molecular imprinting technique with the silica gel as a support. Biochanin A (BCA) was used as a template, 3-aminopropyltriethoxysilane (APTES) as a functional monomer, and tetraethoxysilicane (TEOS) as a cross-linker. Non-imprinted polymer with the sol-gel process (SiO2NIP) was also prepared for comparison. The synthesized polymers were characterized by Fourier transform infrared spectrometry (FTIR), scanning electron microscopy (SEM) and a standard Brunauer-Emett-Teller (BET) and Barret-Joyner-Halenda (BJH) analysis. The obtained results indicated the structural differences between imprinted and non-imprinted polymers. Finally, the SiO2MIP and SiO2NIP were adopted as the adsorbents of solid phase extraction for isolation and preconcentration of biochanin A and its structural analogues-daidzein and genistein from aqueous and urine samples. The performance analysis revealed that SiO2MIP displayed better affinity to the three investigated isoflavones compared with SiO2NIP. The recoveries of spiked samples for studied analytes ranged from 65.7% to 102.6% for molecularly imprinted silica polymer and 8.9-16.0% for non-imprinted sorbents. PMID:25817705

  8. Molecularly imprinted solid phase extraction for the selective HPLC determination of alpha-tocopherol in bay leaves.

    PubMed

    Puoci, F; Cirillo, G; Curcio, M; Iemma, F; Spizzirri, U G; Picci, N

    2007-06-19

    A new sorbent for molecularly imprinted solid phase extraction (MISPE) was synthesized to extract and purify alpha-tocopherol (alpha-TP) from vegetable sources. Molecularly imprinted polymers (MIP) were synthesized using methacrylic acid (MAA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as crosslinking agent using a photo-polymerization procedure. A thermo-polymerization was also performed but no imprinting effect in the resulting materials was raised. The proposed MISPE protocol could overcome the drawback of traditional detection methods, which require pre-treatments of the samples. The possibility to obtain the selective recognition of alpha-TP from natural samples in aqueous mixtures represents one of the main advantages of our materials. Our procedure involves the direct HPLC injection of eluate without any treatment and above all the use of no toxic and biocompatible organic solvents. After the evaluation of the selectivity of the alpha-TP imprinted polymers, the performance of these materials as solid phase extraction (SPE) sorbents was investigated. Our MISPE-HPLC procedure has a high sensitivity, LOD and LOQ were 3.49x10(-7) and 1.16x10(-6) mol L(-1), respectively, as well as good precision (intraday precision below 3.3% and interday precisions below 6.5%) and recovery (60%). Thus, it can be successfully used for the purification of alpha-TP from bay leaves. PMID:17543603

  9. Isolation and detection of steroids from human urine by molecularly imprinted solid-phase extraction and liquid chromatography.

    PubMed

    Gadzała-Kopciuch, Renata; Ricanyová, Júlia; Buszewski, Bogusław

    2009-04-15

    Naturally occurring steroids such as progesterone, testosterone and 17beta-estradiol were analyzed in this study. These bio-identical molecules paradoxically can be either beneficial or harmful. Unfortunately as growth promoters can be toxic and cancerogenic at elevated levels. Due to difficulty in monitoring at trace quantities of these hormones in biological matrices specific adsorption materials molecularly imprinted polymers (MIPs) were used for preconcentration and clean up in sample preparation step. A non-covalent imprinting approach was used for bulk polymerization of progesterone, testosterone and 17beta-estradiol imprinted polymers. Synthesis of MIPs was achieved by thermal, UV and gamma irradiation initiated polymerization whereby were used methacrylic acid (MAA), 4-vinylpyridine (4-VP) as functional monomers, ethylene glycol dimethacrylate (EDMA), trimethylolpropane trimethacrylate (TRIM) as cross-linking agents and acetonitrile, isooctane-toluene (1:99, v/v) and chloroform as porogen solvents. It was also used as initiator 2,2'-azobis(2-methylpropionitrile) (AIBN) or benzyl methyl ether (BME). The MIPs were applied as selective sorbents in solid-phase extraction (SPE). Molecularly imprinted solid-phase extraction (MISPE) considered as hyphenated technique were applied in extraction step before HPLC-DAD analysis of steroids from human urine. PMID:19328752

  10. Novel surface dummy molecularly imprinted silica as sorbent for solid-phase extraction of bisphenol A from water samples.

    PubMed

    Hu, Xiaolei; Wu, Xiao; Yang, Fanfan; Wang, Qiang; He, Chiyang; Liu, Shaorong

    2016-02-01

    A novel surface molecularly imprinted silica composite was prepared by a dummy-template imprinting strategy for the solid-phase extraction (SPE) of bisphenol A (BPA). 2,2-Bis(4-hydroxyphenyl) hexafluoropropane (BPAF) was chosen as the template molecule, and a hybrid technique was used for imprinting procedure. The imprinted silica was characterized by FT-IR spectroscopy, scanning electron microscope, thermo-gravimetric analysis, and nitrogen adsorption-desorption isotherms. The static binding test verified that the imprinted silica had much higher recognition ability for BPA than the non-imprinted silica, and the kinetic adsorption test presented the fast binding kinetics of the surface imprinted silica for BPA. When used as a SPE sorbent, the imprinted silica showed high extraction efficiencies and high enrichment factor for BPA. Based on the imprinted silica, a SPE-HPLC-UV method was developed and successfully applied to the detection of BPA in BPA-spiked lake water, tap water and drinking water samples with a high recovery of 97.3-106.0%, a RSD of 1.2-3.8% (n=3) and a limit of detection (S/N=3) of 0.3 ng/mL. The analysis results of a certified BPA sample also demonstrated the reliability of present method. The new surface dummy molecularly imprinted silica completely avoided the interference of the residual template molecules and greatly improved the binding kinetic of the target molecules. Therefore, it can be used as a good sorbent for SPE of BPA in environmental water samples. PMID:26653420

  11. Matrix molecularly imprinted mesoporous sol-gel sorbent for efficient solid-phase extraction of chloramphenicol from milk.

    PubMed

    Samanidou, Victoria; Kehagia, Maria; Kabir, Abuzar; Furton, Kenneth G

    2016-03-31

    Highly selective and efficient chloramphenicol imprinted sol-gel silica based inorganic polymeric sorbent (sol-gel MIP) was synthesized via matrix imprinting approach for the extraction of chloramphenicol in milk. Chloramphenicol was used as the template molecule, 3-aminopropyltriethoxysilane (3-APTES) and triethoxyphenylsilane (TEPS) as the functional precursors, tetramethyl orthosilicate (TMOS) as the cross-linker, isopropanol as the solvent/porogen, and HCl as the sol-gel catalyst. Non-imprinted sol-gel polymer (sol-gel NIP) was synthesized under identical conditions in absence of template molecules for comparison purpose. Both synthesized materials were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and nitrogen adsorption porosimetry, which unambiguously confirmed their significant structural and morphological differences. The synthesized MIP and NIP materials were evaluated as sorbents for molecularly imprinted solid phase extraction (MISPE) of chloramphenicol in milk. The effect of critical extraction parameters (flow rate, elution solvent, sample and eluent volume, selectivity coefficient, retention capacity) was studied in terms of retention and desorption of chloramphenicol. Competition and cross reactivity tests have proved that sol-gel MIP sorbent possesses significantly higher specific retention and enrichment capacity for chloramphenicol compared to its non-imprinted analogue. The maximum imprinting factor (IF) was found as 9.7, whereas the highest adsorption capacity of chloramphenicol by sol-gel MIP was 23 mg/g. The sol-gel MIP was found to be adequately selective towards chloramphenicol to provide the necessary minimum required performance limit (MRPL) of 0.3 μg/kg set forth by European Commission after analysis by LC-MS even without requiring time consuming solvent evaporation and sample reconstitution step, often considered as an integral part in solid phase extraction work-flow. Intra and

  12. Synthesis of a molecularly imprinted sorbent for selective solid-phase extraction of β-N-methylamino-L-alanine.

    PubMed

    Svoboda, Pavel; Combes, Audrey; Petit, Julia; Nováková, Lucie; Pichon, Valérie

    2015-11-01

    The aim of the work was to synthesize a molecularly imprinted material for the selective solid-phase extraction (SPE) of β-N-methylamino-L-alanine (L-2-amino-3-methylpropionic acid; BMAA) from cyanobacterial extracts. BMAA and its structural analogs that can be used as template are small, polar and hydrophilic molecules. These molecules are poorly soluble in organic solvents that are commonly used for the synthesis of acrylic-based polymers. Therefore, a sol gel approach was chosen to carry out the synthesis and the resulting sorbents were evaluated with different extraction procedures in order to determine their ability to selectively retain BMAA. The presence of imprinted cavities in the sorbent was demonstrated by comparing elution profiles obtained by using molecularly imprinted silica (MIS) and non-imprinted silica (NIS) as a control. The molecularly imprinted solid-phase extraction (MISPE) procedure was first developed in a pure medium (acetonitrile) and further optimized for the treatment of cyanobacterial samples. It was characterized by high elution recoveries (89% and 77% respectively in pure and in real media).The repeatability of the extraction procedure in pure medium, in real medium and the reproducibility of MIS synthesis all expressed as RSD values of extraction recovery of BMAA were equal to 3%, 12% and 5%, respectively. A MIS capacity of 0.34 µmol/g was measured. The matrix effects, which affected the quantification of BMAA when employing a mixed mode sorbent, were completely removed by adding a clean-up step of the mixed-mode sorbent extract on the MIS. PMID:26452922

  13. Molecularly imprinted macroporous monoliths for solid-phase extraction: Effect of pore size and column length on recognition properties.

    PubMed

    Vlakh, E G; Stepanova, M A; Korneeva, Yu M; Tennikova, T B

    2016-09-01

    The series of macroporous monolithic molecularly imprinted monoliths differed by pore size, column length (volume) and amount of template used for imprinting was synthesized using methacrylic acid and glycerol dimethacrylate as co-monomers and antibiotic ciprofloxacin as a template. The prepared monoliths were characterized regarding to their permeability, pore size, porosity, and resistance to the flow of a mobile phase. The surface morphology was also analyzed. The slight dependence of imprinting factor on flow rate, as well as its independence on pore size of macroporous molecularly imprinted monolithic media was observed. The column obtained at different conditions exhibited different affinity of ciprofloxacin to the imprinted sites that was characterized with Kdiss values in the range of 10(-5)-10(-4)M. The solid-phase extraction of ciprofloxacin from such biological liquids as human blood serum, human urine and cow milk serum was performed using the developed monolithic columns. In all cases, the extraction was found to be 95.0-98.6%. Additionally, the comparison of extraction of three fluoroqinolone analogues, e.g. ciprofloxacin, levofloxacin and moxifloxacin, from human blood plasma was carried out. Contrary to ciprofloxacin extracted with more than 95%, this parameter did not exceed 40% for its analogues. PMID:27433985

  14. Application of molecularly imprinted polymer solid-phase extraction for salivary cotinine.

    PubMed

    Vitor, Ricardo Vilela; Martins, Matheus Coutinho Gonçalves; Figueiredo, Eduardo Costa; Martins, Isarita

    2011-06-01

    A method constituted by molecularly imprinted solid-phase extraction (MISPE) with high-performance liquid chromatography coupled to diode array detector (HPLC-DAD) was developed for cotinine analysis in saliva samples. For this purpose, the separation was carried out with a C18 reversed-phase column at 20 °C. The mobile phase which was composed of a mixture of 09:91 (v/v) acetonitrile/phosphate buffer, pH 6.3, was delivered with isocratic flow rate at 1.4 mL min(-1). Employing MISPE, the best conditions were achieved with 1.5 mL of saliva plus 1.5 mL of 0.1 mol L(-1) of acetate buffer, pH 5.5, which were then passed through a cartridge previously conditioned with 2 mL acetonitrile, 2 mL methanol, and 2 mL of 0.1 mol L(-1) sodium acetate buffer, pH 5.5. The washing was carried out with 1 mL deionized water, 1 mL of 0.1 mol L(-1) sodium hydroxide, and 1 mL hexane; finally; the cotinine elution was carried out with 3 mL methanol/water (97.5: 2.5, v/v). Linearity ranged from 30 to 500 ng mL(-1) with r > 0.99. Intra-assay, interassay precision, and accuracy ranged from 3.1% to 10.1%, 5.2% to 15.9%, and 99.22% to 111.17%, respectively. The detection and quantification limits were 10 and 30 ng mL(-1), respectively. This investigation has provided a reliable method for routine cotinine determination in saliva, and it is an important tool for monitoring cigarette smoke exposure in smokers. The method was applied in five smokers' samples who consumed around five to 20 cigarettes per day and the values of cotinine in saliva were from 66.7 to 316.16 ng mL(-1). PMID:21448605

  15. 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...

  16. Selective solid-phase extraction using molecularly imprinted polymer as a sorbent for the analysis of fenarimol in food samples.

    PubMed

    Khan, Shagufta; Bhatia, Tejasvi; Trivedi, Purushottam; Satyanarayana, G N V; Mandrah, Kapil; Saxena, Prem Narayan; Mudiam, Mohana Krishna Reddy; Roy, Somendu Kumar

    2016-05-15

    In the present communication, a non-covalent fenarimol-imprinted polymer was synthesized by precipitation polymerization technique using methacrylic acid (MAA) as a functional monomer, ethylene glycol dimethacrylate (EGDMA) as a cross-linker, and azobisisobutyronitrile (AIBN) as an initiator in different porogenic solvent. Binding study of molecularly imprinted and non-imprinted polymer (MIP and NIP) showed that MIP possesses a higher affinity towards this analyte compared to NIP. The binding affinity of MIP was calculated by static and kinetic adsorption study. Further, a MIP based cartridge was designed to use in extraction process, necessary for specific determination and quantification of the fungicide in food matrices. Under the optimum conditions, developed method was found to be linear (R(2)=0.9999-0.9994). Limit of detection (LOD) and limit of quantitation (LOQ) in samples were 0.03-0.06 and 0.12-0.21 μg mL(-1), respectively. The rate of recovery of fenarimol was 91.16-99.52% on MIPs. The validated method of molecularly imprinted solid-phase extraction (MISPE) cartridge was successfully applied to the food matrices and compared with commercial sorbent (RP18 and Oasis HLB). However we feel, this method has promising applications in the routine analysis of food samples in industry. PMID:26776046

  17. Synthesis and application of surface-imprinted activated carbon sorbent for solid-phase extraction and determination of copper (II)

    NASA Astrophysics Data System (ADS)

    Li, Zhenhua; Li, Jingwen; Wang, Yanbin; Wei, Yajun

    2014-01-01

    A new Cu(II)-imprinted amino-functionalized activated carbon sorbent was prepared by a surface imprinting technique for selective solid-phase extraction (SPE) of Cu(II) prior to its determination by inductively coupled plasma atomic emission spectrometry (ICP-AES). Experimental conditions for effective adsorption of Cu(II) were optimized with respect to different experimental parameters using static and dynamic procedures in detail. Compared with non-imprinted sorbent, the ion-imprinted sorbent had higher selectivity and adsorption capacity for Cu(II). The maximum static adsorption capacity of the ion-imprinted and non-imprinted sorbent for Cu(II) was 26.71 and 6.86 mg g-1, respectively. The relatively selectivity factor values (αr) of Cu(II)/Zn(II), Cu(II)/Ni(II), Cu(II)/Co(II) and Cu(II)/Pb(II) were 166.16, 50.77, 72.26 and 175.77, respectively, which were greater than 1. Complete elution of the adsorbed Cu(II) from Cu(II)-imprinted sorbent was carried out using 2 mL of 0.1 mol L-1 EDTA solution. The relative standard deviation of the method was 2.4% for eleven replicate determinations. The method was validated for the analysis by two certified reference materials (GBW 08301, GBW 08303), the results obtained is in good agreement with standard values. The developed method was also successfully applied to the determination of trace copper in natural water samples with satisfactory results.

  18. Preparation of l-phenylalanine-imprinted solid-phase extraction sorbent by Pickering emulsion polymerization and the selective enrichment of l-phenylalanine from human urine.

    PubMed

    Li, Ji; Hu, Xiaoling; Guan, Ping; Zhang, Xiaoyan; Qian, Liwei; Zhang, Nan; Du, Chunbao; Song, Renyuan

    2016-05-01

    A novel l-phenylalanine molecularly imprinted solid-phase extraction sorbent was synthesized by the combination of Pickering emulsion polymerization and ion-pair dummy template imprinting. Compared to other polymerization methods, the molecularly imprinted polymers thus prepared exhibit a high specific surface, large pore diameter, and appropriate particle size. The key parameters for solid-phase extraction were optimized, and the result indicated that the molecularly imprinted polymer thus prepared exhibits a good recovery of 98.9% for l-phenylalanine. Under the optimized conditions of the procedure, an analytical method for l-phenylalanine was well established. By comparing the performance of the molecularly imprinted polymer and a commercial reverse-phase silica gel, the obtained molecularly imprinted polymer as an solid-phase extraction sorbent is more suitable, exhibiting high precision (relative standard deviation 3.2%, n = 4) and a low limit of detection (60.0 ± 1.9 nmol·L(-1) ) for the isolation of l-phenylalanine. Based on these results, the combination of the Pickering emulsion polymerization and ion-pair dummy template imprinting is effective for preparing selective solid-phase extraction sorbents for the separation of amino acids and organic acids from complex biological samples. PMID:26991761

  19. Preparation of molecularly imprinted solid phase extraction using bensulfuron-methyl imprinted polymer and clean-up for the sulfonylurea-herbicides in soybean.

    PubMed

    Tang, Kaijie; Chen, Shangwei; Gu, Xiaohong; Wang, Haijun; Dai, Jun; Tang, Jian

    2008-04-28

    A pre-treatment methodology based on the molecularly imprinted solid phase extraction (MI-SPE) procedure was developed for the determination of bensulfuron-methyl (BSM), tribenuron-methyl (TBM), metsulfuron-methyl (MSM) and nicosulfuron (NS) in soybean samples. A molecular imprinted polymer (MIP) was prepared by precipitation polymerization using BSM as the template molecule, alpha-methacrylic acid (MAA) as the functional monomer, trimethylolpropane trimethacrylate (TRIM) as the cross-linker and dichloromethane as the porogen. The binding behaviors of the template BSM and its analogues on the MIP were evaluated by high performance liquid chromatography (HPLC). Then, solid phase extraction (SPE) with a BSM molecularly imprinted polymer (BSM-MIP) as adsorbent was investigated and the optimum loading, washing, and eluting conditions for MI-SPE of the selected BSM, MSM, TBM, and NS were established. The optimized MI-SPE procedure was used to extract the sulfonylureas and a high recovery was obtained in the soybean samples. PMID:18405688

  20. A molecularly imprinted polymer for the selective solid-phase extraction of dimethomorph from ginseng samples.

    PubMed

    Xu, Xuanwei; Liang, Shuang; Meng, Xinxin; Zhang, Min; Chen, Ying; Zhao, Dan; Li, Yueru

    2015-04-15

    A molecularly imprinted polymer (MIP) was synthesized and evaluated to selectively extract dimethomorph from ginseng samples. Dimethomorph molecularly imprinted polymers with template to monomer molar ratios were contrived and developed via precipitation polymerization employing methacrylic acid as functional monomer, ethylene dimethacrylate as cross-linker and butanone:N-heptane (7:3, v:v)as porogen. The LOD (limit of detection) of this method was 0.002 mg kg(-1), and the LOQ (limit of quantification) was 0.005 mg kg(-1). The different spiked level of ginseng was 0.1 mg kg(-1), 1.0 mg kg(-1), 5.0 mg kg(-1), and the average recovery of dimethomrph was 89.2-91.6%. Under the optimized condition, good linearity was obtained from 0.01 to 5 mg kg(-1) (r(2) ≥ 0.9997) with the relative standard deviations of less than 3.20%. This proposed MISPE-GC procedure eliminated the effect of template leakage on quantitative analysis and could be applied to direct determination of dimethomrph in ginseng samples. PMID:25795323

  1. Preparation and application of sulfaguanidine-imprinted polymer on solid-phase extraction of pharmaceuticals from water.

    PubMed

    Mutavdžić Pavlović, Dragana; Nikšić, Korana; Livazović, Sara; Brnardić, Ivan; Anžlovar, Alojz

    2015-01-01

    The molecularly imprinted polymers (MIPs) with sulfaguanidine as a template, methacrylic acid, 4-vinylpyridine, and 2-hydroxyethyl methacrylate as functional monomers, ethylene glycol dimethacrylate as a cross-linker and 2,2'-azobis-isobutyronitrile as an initiator have been prepared through the cross-link reaction of polymerization. Solid-phase extraction (SPE) procedure for the extraction of sulfaguanidine from water samples using the prepared MIPs and non-imprinted (NIPs) was evaluated. The best MIP in combination with commercial sorbents was applied for simultaneous extraction of eight pharmaceuticals. New SPE cartridges were prepared by combination of optimal produced MIP and Oasis HLB in 6 mL of polypropilene SPE reservoir. The developed method which includes new SPE cartridge (MIPMAA-Oasis HLB, 400mg/6 mL) and thin-layer chromatography was validated. The method provides a linear response over the concentration range of 0.5-150 μg/L, depending on the pharmaceutical with the correlation coefficients>0.9843 in all cases except for norfloxacin (0.9770) and penicillin G procaine (0.9801). Also, the method has revealed low limits of detection (0.25-20 μg/L), good precision (intra and inter-day), a relative standard deviation below 15% and recoveries above 95% for all eight pharmaceuticals. The developed method by using newly prepared SPE cartridge has been successfully applied to the analysis of production wastewater samples from pharmaceutical industry. PMID:25281079

  2. Molecularly imprinted polymers combination with deep eutectic solvents for solid-phase extraction of caffeic acid from hawthorn.

    PubMed

    Li, Guizhen; Tang, Weiyang; Cao, Weimin; Wang, Qian; Zhu, Tao

    2015-08-01

    Molecularly imprinted polymers (MIPs) with caffeic acid as template and non-imprinted polymers (NIPs) materials were prepared in the same procedure. Field emission scanning electron microscopy (FE-SEM) and adsorption capacity test were used to evaluate characteristic of the new materials. MIPs, NIPs and C18 were used for rapid purification of caffeic acid from hawthorn with solid-phase extraction ( SPE) , and extract yields of caffeic acid with the proposed materials were 3.46 µg/g, 1.01 µg/g and 1.17 µg/g, respectively. To optimize the MIPs-SPE procedures, different kinds of elution solutions were studied. Deep eutectic solvents (DESs) were prepared by choline chloride (ChCl)-glycerol (1/2, n/n) and choline chloride-urea (1/ 2, n/n). Methanol was mixed with the two kinds of DESs (glycerol-based DESs, urea-based DESs) in different ratios (0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, v/v), and they were used to investigated as elution solutions in the above MIPs-SPE procedures. The results showed that MIPs were potential SPE materials, and methanol/ glycerol-based DESs (3 :1, v/v) had the best elution capability with the recovery of 82.32%. PMID:26749853

  3. Molecularly imprinted solid-phase extraction for the selective determination of valnemulin in feeds with high performance liquid chromatography.

    PubMed

    Guo, Hongbin; Liu, Kaiyong; Liu, Yahong; Fang, Binghu; Liu, Min; He, Limin; Zeng, Zhenling

    2011-01-15

    A simple, sensitive and reproducible high performance liquid chromatographic method was developed for determining valnemulin in feeds. Feed samples were extracted with ethyl acetate under alkaline condition, cleaned up by molecularly imprinted solid-phase extraction, and analyzed by high performance liquid chromatography with ultraviolet detection. The characteristics of the synthesized polymer were evaluated and the loading capacity of the polymer was about 1000 μg analyte/g imprinted polymer. The new procedure for the feed sample cleanup using the prepared polymer cartridge gave higher recoveries and fewer matrix interferences. The assay exhibited a linear dynamic range of 5.0-200 mg kg(-1) with the correlation coefficient above 0.9993. Recoveries of valnemulin from feed samples spiked at 5.0, 20 and 50 mg kg(-1) ranged between 76.0% and 94.4% with relative standard deviations of less than 9%. The limit of detection for valnemulin in feeds was 1 mg kg(-1). PMID:21212028

  4. 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...

  5. Selective mixed-bed solid phase extraction of atrazine herbicide from environmental water samples using molecularly imprinted polymer.

    PubMed

    Zarejousheghani, Mashaalah; Fiedler, Petra; Möder, Monika; Borsdorf, Helko

    2014-11-01

    A novel approach for the selective extraction of organic target compounds from water samples has been developed using a mixed-bed solid phase extraction (mixed-bed SPE) technique. The molecularly imprinted polymer (MIP) particles are embedded in a network of silica gel to form a stable uniform porous bed. The capabilities of this method are demonstrated using atrazine as a model compound. In comparison to conventional molecularly imprinted-solid phase extraction (MISPE), the proposed mixed-bed MISPE method in combination with gas chromatography-mass spectrometry (GC-MS) analysis enables more reproducible and efficient extraction performance. After optimization of operational parameters (polymerization conditions, bed matrix ingredients, polymer to silica gel ratio, pH of the sample solution, breakthrough volume plus washing and elution conditions), improved LODs (1.34 µg L(-1) in comparison to 2.25 µg L(-1) obtained using MISPE) and limits of quantification (4.5 µg L(-1) for mixed-bed MISPE and 7.5 µg L(-1) for MISPE) were observed for the analysis of atrazine. Furthermore, the relative standard deviations (RSDs) for atrazine at concentrations between 5 and 200 µg L(-1) ranged between 1.8% and 6.3% compared to MISPE (3.5-12.1%). Additionally, the column-to-column reproducibility for the mixed-bed MISPE was significantly improved to 16.1%, compared with 53% that was observed for MISPE. Due to the reduced bed-mass sorbent and at optimized conditions, the total amount of organic solvents required for conditioning, washing and elution steps reduced from more than 25 mL for conventional MISPE to less than 2 mL for mixed-bed MISPE. Besides reduced organic solvent consumption, total sample preparation time of the mixed-bed MISPE method relative to the conventional MISPE was reduced from more than 20 min to less than 10 min. The amount of organic solvent required for complete elution diminished from 3 mL (conventional MISPE) to less than 0.4 mL with the mixed

  6. Fast HPLC-MS/MS Method for Determining Penicillin Antibiotics in Infant Formulas Using Molecularly Imprinted Solid-Phase Extraction

    PubMed Central

    Díaz-Bao, Mónica; Barreiro, Rocío; Miranda, José Manuel; Cepeda, Alberto; Regal, Patricia

    2015-01-01

    The dairy cattle may suffer from different infections relatively often, but the inflammation of the mammary gland is very important to the farmer. These infections are frequently treated with penicillin antimicrobial drugs. However, their use may result in the presence of residues in animal products, such as milk powder and/or infant formulas, and it represents a potential risk for consumers. To monitor this, the EU has defined safe maximum residue limits (MRLs) through Commission Regulation (EU) number 37/2010. Although LC-MS is a trustful option for confirmation and quantification of antibiotics, the analysis of real samples with complex matrices frequently implies previous clean-up steps. In this work, precipitation polymerization has been used and different molecularly imprinted polymer (MIP) sorbents were tested and optimized for the fast and simultaneous solid-phase extraction (MISPE) of eight common penicillins (ampicillin, amoxicillin, oxacillin, penicillin G, penicillin V, cloxacillin, dicloxacillin, and nafcillin). The extracts were analyzed using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) and the applicability of these polymers as sorbents for the extraction of penicillins at MRL levels in milk powder (infant formulas) was proved. The limits of detection and quantification were below the legal tolerances, except for LOQ for oxacillin and cloxacillin. PMID:25785233

  7. Fast HPLC-MS/MS Method for Determining Penicillin Antibiotics in Infant Formulas Using Molecularly Imprinted Solid-Phase Extraction.

    PubMed

    Díaz-Bao, Mónica; Barreiro, Rocío; Miranda, José Manuel; Cepeda, Alberto; Regal, Patricia

    2015-01-01

    The dairy cattle may suffer from different infections relatively often, but the inflammation of the mammary gland is very important to the farmer. These infections are frequently treated with penicillin antimicrobial drugs. However, their use may result in the presence of residues in animal products, such as milk powder and/or infant formulas, and it represents a potential risk for consumers. To monitor this, the EU has defined safe maximum residue limits (MRLs) through Commission Regulation (EU) number 37/2010. Although LC-MS is a trustful option for confirmation and quantification of antibiotics, the analysis of real samples with complex matrices frequently implies previous clean-up steps. In this work, precipitation polymerization has been used and different molecularly imprinted polymer (MIP) sorbents were tested and optimized for the fast and simultaneous solid-phase extraction (MISPE) of eight common penicillins (ampicillin, amoxicillin, oxacillin, penicillin G, penicillin V, cloxacillin, dicloxacillin, and nafcillin). The extracts were analyzed using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) and the applicability of these polymers as sorbents for the extraction of penicillins at MRL levels in milk powder (infant formulas) was proved. The limits of detection and quantification were below the legal tolerances, except for LOQ for oxacillin and cloxacillin. PMID:25785233

  8. Solid phase extraction membrane

    SciTech Connect

    Carlson, Kurt C; Langer, Roger L

    2002-11-05

    A wet-laid, porous solid phase extraction sheet material that contains both active particles and binder and that possesses excellent wet strength is described. The binder is present in a relatively small amount while the particles are present in a relatively large amount. The sheet material is sufficiently strong and flexible so as to be pleatable so that, for example, it can be used in a cartridge device.

  9. Molecularly imprinted polymer as sorbent in micro-solid phase extraction of ochratoxin A in coffee, grape juice and urine.

    PubMed

    Lee, Tien Ping; Saad, Bahruddin; Khayoon, Wejdan Shakir; Salleh, Baharuddin

    2012-01-15

    A simple, environmental friendly and selective sample preparation technique employing porous membrane protected micro-solid phase extraction (μ-SPE) loaded with molecularly imprinted polymer (MIP) for the determination of ochratoxin A (OTA) is described. After the extraction, the analyte was desorbed using ultrasonication and was analyzed using high performance liquid chromatography. Under the optimized conditions, the detection limits of OTA for coffee, grape juice and urine were 0.06 ng g(-1), 0.02 and 0.02 ng mL(-1), respectively while the quantification limits were 0.19 ng g(-1), 0.06 and 0.08 ng mL(-1), respectively. The recoveries of OTA from coffee spiked at 1, 25 and 50 ng g(-1), grape juice and urine samples at 1, 25 and 50 ng mL(-1) ranged from 90.6 to 101.5%. The proposed method was applied to thirty-eight samples of coffee, grape juice and urine and the presence of OTA was found in eighteen samples. The levels found, however, were all below the legal limits. PMID:22265478

  10. Synthesis and characterization of molecularly imprinted polymer nanoparticles for coenzyme Q10 dispersive micro solid phase extraction.

    PubMed

    Contin, Mario; Bonelli, Pablo; Lucangioli, Silvia; Cukierman, Ana; Tripodi, Valeria

    2016-07-22

    Molecularly imprinted polymer nanoparticles (MIPNPs) with the ability to recognize coenzyme Q10 (CoQ10) were synthesised in order to be employed as sorbent in a dispersive micro-solid phase extraction (DMSPE) for the determination of CoQ10 in a liver extract. CoQ10 is a redox-active, lipophilic substance integrated in the mitochondrial respiratory chain which acts as an electron carrier, shuttling electrons from complex I (NADH-ubiquinone oxidoreductase) and II (succinate-ubiquinone oxidoreductase) to complex III (ubiquinol-cytochrome c reductase), for the production of cellular energy. The MIPNPs were synthesised by precipitation polymerization using coenzyme Q0 as the dummy template, methacrylic acid as the functional monomer, an acetonitrile: water mixture as the porogen, ethylene glycol dimethacrylate as the crosslinker and potassium persulfate as initiator. The nanoparticles were characterized by microscopy, capillary electrophoresis, dynamic light scattering, N2 adsorption-desorption isotherms, and infrared spectroscopy. The MIPNPs demonstrated the presence of selective cavities complementary to the quinone nucleus of CoQ10, leading to a specific recognition of CoQ10 compared with related compounds. In the liver extract the relative CoQ10 peak area (CoQ10 area/total peak area) increased from 4.6% to 25.4% after the DMSPE procedure. The recovery percentage of CoQ10 from the liver matrix was between 70.5% and 83.7% quantified against CoQ10 standard processed under the same conditions. The DMSPE procedure allows the elution of almost all the CoQ10 retained (99.4%) in a small volume (200μL), allowing the sample to be concentrated 2.5 times (LOD: 1.1μgg(-1) and LOQ: 3.7μgg(-1) of tissue). The resulted clean up of the sample, the improvement in peak shape and baseline and the reduction of interferences, evidence that the MIPNPs could potentially be applied as sorbent in a DMSPE with satisfactory results and with a minimum amount of sorbent (1mg). PMID:27317007

  11. Development of surface imprinted core-shell nanoparticles and their application in a solid-phase dispersion extraction matrix for methyl parathion.

    PubMed

    Tan, Lei; Li, Weiming; Li, He; Tang, Youwen

    2014-04-01

    Applying molecular imprinting techniques to the surface of functionalized SiO2 allows the preparation of molecularly imprinted polymers (MIPs) with accessible, high affinity and surface exposed binding sites. This paper demonstrates a new strategy for producing such hybrid organic-inorganic surface imprinted silica nanoparticles for specific recognition of methyl parathion. The technique provides surface grafting imprinting in chloroform using amino modified silica nanoparticles as supports, acrylamide as the functional monomer, γ-methacryloxypropyl trimethoxy silane as the grafting agent, and methyl parathion as a template. The amino propyl functional monomer layer directs the selective occurrence of imprinting polymerization at the silica surface through copolymerization of grafting agents with functional monomers, but also acts as an assistive monomer to drive the template into the formed polymer shells to create effective recognition sites. The resulting MIPs-SiO2 nanoparticles display three-dimensional core-shell architectures and large surface areas. The molecularly imprinted shell provides recognition sites for methyl parathion, with the materials exhibiting excellent performance for selecting the template. Using MIPs-SiO2 nanoparticles as a matrix of solid-phase dispersion extraction sorbents, trace amounts of methyl parathion are selectivity extracted from pear and green vegetable samples while simultaneously eliminating matrix interferences, attaining recoveries of 84.7-94.4% for the samples. PMID:24576608

  12. Molecularly imprinted polymers with novel functional monomer for selective solid-phase extraction of gastrodin from the aqueous extract of Gastrodia elata.

    PubMed

    Ji, Wenhua; Chen, Lingxiao; Ma, Xiuli; Wang, Xiao; Gao, Qianshan; Geng, Yanling; Huang, Luqi

    2014-05-16

    Molecular imprinted polymers (MIPs) with high selectivity and affinity to gastrodin in water were designed using allyl 2,3,4,6-tetra-O-acetyl-glucopyranoside (TAGL) and 1,2,3,4,5-pentafluoro-6-vinylbenzene (PFVB) as novel functional monomers. Binding characterization of pre-polymerization complexes was researched by nuclear magnetic resonance (NMR) and the MIPs were characterized by scanning electron microscopy (SEM). The properties involving adsorption isotherm, adsorption kinetics and selective recognition capacity were evaluated. The MIPs/TAGL exhibited good site accessibility in which it only took 30min to achieve adsorption equilibrium and highly selective recognition for the template. Furthermore, the performance of the MIPs/TAGL as solid phase extraction material was investigated in detail and hot water at 50°C served as the eluting solvent. Pure gastrodin with the recovery of 76.6% was obtained from the aqueous extract of Gastrodia elata roots. PMID:24703361

  13. Molecularly imprinted solid-phase extraction combined with electrochemical oxidation fluorimetry for the determination of methotrexate in human serum and urine

    NASA Astrophysics Data System (ADS)

    Chen, Suming; Zhang, Zhujun

    2008-06-01

    The method of synthesis and evaluation of molecularly imprinted polymers was reported. As a selective solid-phase extraction sorbent, the polymers were coupled with electrochemical fluorimetry detection for the efficient determination of methotrexate in serum and urine. Methotrexate was preconcentrated in the molecularly imprinted solid-phase extraction microcolumn packed with molecularly imprinted polymers, and then eluted. The eluate was detected by fluorescence spectrophotometer after electrochemical oxidation. The conditions of preconcentration, elution, electrochemical oxidation and determination were carefully studied. Under the selected experimental conditions, the calibration graph of the fluorescence intensity versus methotrexate concentration was linear from 4 × 10 -9 g mL -1 to 5 × 10 -7 g mL -1, and the detection limit was 8.2 × 10 -10 g mL -1 (3 σ). The relative standard deviation was 3.92% ( n = 7) for 1 × 10 -7 g mL -1 methotrexate. The experiments showed that the selectivity and sensitivity of fluorimetry could be greatly improved by the proposed method. This method has been successfully applied to the determination of methotrexate. At the same time, the binding characteristics of the polymers to the methotrexate were evaluated by batch and dynamic methods.

  14. Selective and simultaneous determination of trace bisphenol A and tebuconazole in vegetable and juice samples by membrane-based molecularly imprinted solid-phase extraction and HPLC.

    PubMed

    Wu, Ya-Ting; Zhang, Yan-Hong; Zhang, Meng; Liu, Fei; Wan, Ying-Chun; Huang, Zheng; Ye, Lei; Zhou, Qi; Shi, Yun; Lu, Bin

    2014-12-01

    Nanofibrous molecularly imprinted membranes (nano-MIMs) with multi-analyte selectivity were prepared by encapsulating two types of molecularly imprinted polymer nanoparticles (MIP-NPs) into electrospun polyvinyl alcohol nanofibers. The obtained nano-MIMs maintained high molecular selectivity offered by each of the MIP-NPs. Nano-MIM embedding BPA-imprinted nanoparticles and TBZ-imprinted nanoparticles together showed the highest binding selectivity for acid bisphenol A (BPA) and basic tebuconazole (TBZ). This nano-MIM was used as affinity material of membrane-based molecularly imprinted solid-phase extraction (m-MISPE) to extract trace BPA and TBZ in vegetables and juices simultaneously. The recoveries of BPA and TBZ from different samples were higher than 70.33% with RSDs lower than 9.57%. m-MISPE gave better HPLC separation efficiencies and higher recoveries than conventional SPE based on C18/SCX. Multi-analyte selective m-MISPE combined with HPLC realized selective and simultaneous determination of several trace analytes with opposite charges/polarities in different food samples. PMID:24996366

  15. Analysis of permethrin isomers in composite diet samples by molecularly imprinted solid-phase extraction and isotope dilution gas chromatography-ion trap mass spectrometry.

    PubMed

    Vonderheide, Anne P; Boyd, Brian; Ryberg, Anna; Yilmaz, Ecevit; Hieber, Thomas E; Kauffman, Peter E; Garris, Sherry T; Morgan, Jeffrey N

    2009-05-29

    Determination of an individual's aggregate dietary ingestion of pesticides entails analysis of a difficult sample matrix. Permethrin-specific molecularly imprinted polymer (MIP) solid-phase extraction cartridges were developed for use as a sample preparation technique for a composite food matrix. Vortexing with acetonitrile and centrifugation were found to provide optimal extraction of the permethrin isomers from the composite foods. The acetonitrile (with 1% acetic acid) was mostly evaporated and the analytes reconstituted in 90:10 water/acetonitrile in preparation for molecularly imprinted solid-phase extraction. Permethrin elution was accomplished with acetonitrile and sample extracts were analyzed by isotope dilution gas chromatography-ion trap mass spectrometry. Quantitation of product ions provided definitive identification of the pesticide isomers. The final method parameters were tested with fortified composite food samples of varying fat content (1%, 5%, and 10%) and recoveries ranged from 99.3% to 126%. Vegetable samples with incurred pesticide levels were also analyzed with the given method and recoveries were acceptable (81.0-95.7%). Method detection limits were demonstrated in the low ppb range. Finally, the applicability of the MIP stationary phase to extract other pyrethroids, specifically cyfluthrin and cypermethrin, was also investigated. PMID:19393156

  16. Synthesis and evaluation of dummy molecularly imprinted microspheres for the specific solid-phase extraction of six anthraquinones from slimming tea.

    PubMed

    Wu, Xingqiang; Liang, Shuxuan; Ge, Xusheng; Lv, Yunkai; Sun, Hanwen

    2015-05-01

    Dummy molecularly imprinted microspheres with danthron as template were synthesized and their performance was evaluated. Accelerated solvent extraction can rapidly and effectively remove template molecules from the microspheres. The microspheres were applied as a specific sorbent for solid-phase extraction of six anthraquinones from slimming tea, showing excellent affinity and high selectivity to danthron and the target analytes. The molecular recognition mechanisms were discussed by the experimental validation with IR spectroscopy. The sample was treated using accelerated solvent extraction followed by dummy molecularly imprinted microspheres solid-phase extraction. Under the optimized ultra high performance liquid chromatographic conditions, the six target analytes can be baseline separated in 8 min, and good linearity was obtained in a range of 0.1-40 μg/mL with the correlation coefficient (r(2)) of ≥0.9998. The method limit of quantification was in a range of 1-2 mg/kg, it can ensure analysis of anthraquinones at mg/kg level. The intra- and interday precision (RSD, n = 6) for the analysis of the six analytes in a slimming tea was less than 4.5 and 5.4%, respectively. The developed method can be applied for the selective extraction, effective separation, and rapid determination of six anthraquinones in slimming tea. PMID:25677958

  17. Design of a new cartridge for selective solid phase extraction using molecularly imprinted polymers: selective extraction of theophylline from human serum samples.

    PubMed

    Khorrami, Afshin Rajabi; Rashidpur, Amene

    2009-11-15

    This paper describes design of a new cartridge for selective solid phase extraction (SPE) using molecularly imprinted polymers (MIPs). The apparatus which is termed solvent extraction-MISPE (SE-MISPE) cartridge, consisted of a modified conventional micro test tube and has been developed to perform simultaneous forward-extraction of analyte from aqueous sample solution to an organic phase and back-extraction to MIP solid phase. In order to evaluate the performance of the proposed method, extraction of theophylline (THP) from human serum sample was investigated. An appropriate amount of THP-imprinted polymer was placed in the bottom of the micro tube and an organic solvent pipetted onto it and left to swell the polymer completely. A polyethylene frit to secure MIP particles was positioned by two Teflon rings such that it was fixed below the level of the organic layer. Then, aqueous sample solution containing THP was layered over the organic phase and the lid was closed. After completion of extraction, the organic and aqueous phases were removed and the adsorbed analyte was desorbed using a polar organic solvent. In order to reach the highest recovery, the experimental parameters such as the type of organic solvent, pH and ionic strength of aqueous phase, organic to aqueous volume ratio, time of extraction, type and amount of desorbent solvent were optimized. Under the experimental conditions, a plot of HPLC peak areas vs. initial concentrations of THP in the concentration interval of 0.5-30 microg ml(-1) showed a good linearity (r=0.9974). The limit of detection (LOD) and limit of quantification (LOQ) based on three and ten times of the noise of HPLC profile were 0.09 and 0.3 microg ml(-1), respectively. The relative standard deviation (RSD) of the proposed method for the extraction and determination of 5 microg THP from 200 microl standard sample solution for 3 replicate measurements was 3.5%. The results showed that by means of the proposed cartridge, THP could

  18. Preparation of molecular imprinted microspheres based on inorganic-organic co-functional monomer for miniaturized solid-phase extraction of fluoroquinolones in milk.

    PubMed

    Wang, Hui; Wang, Ruiling; Han, Yehong

    2014-02-15

    An inorganic-organic co-functional monomer, methacrylic acid-vinyltriethoxysilan (MAA-VTES) was designed for the synthesis of molecularly imprinted microspheres (MIMs). By virtue of the aqueous suspension polymerization and dummy template (pazufloxacin), the obtained MAA-VTES based MIMs exhibited good recognition and selectivity to fluoroquinolones (FQs), and were successfully applied as selective sorbents of a miniaturized home-made solid phase extraction device for the determination of ofloxacin (OFL), lomefloxacin (LOM) and ciprofloxacin (CIP) in milk samples. Under the optimum conditions of the miniaturized molecularly imprinted solid phase extraction (mini-MISPE) coupled with liquid chromatography-ultraviolet detector (LC-UV), good linearities were obtained for three FQs in a range of 0.2-20.0μgmL(-1) and the average recoveries at three spiked levels were ranged from 87.2% to 106.1% with the relative standard deviation (RSD) less than 5.4%. The presented co-functional monomer based mini-MISPE-LC-UV protocol introduced the rigidity and flexibility of inorganic silicon materials, exhibited excellent extraction performance towards targets, and could be potentially applied to the determination of FQs in milk samples. PMID:24448515

  19. Molecularly imprinted solid-phase extraction for the determination of ten macrolide drugs residues in animal muscles by liquid chromatography-tandem mass spectrometry.

    PubMed

    Song, Xuqin; Zhou, Tong; Liu, Qingying; Zhang, Meiyu; Meng, Chenying; Li, Jiufeng; He, Limin

    2016-10-01

    A simple and sensitive method based on molecularly imprinted solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry was developed for the determination of the residues of ten macrolide drugs in swine, cattle and chicken muscles samples. The molecularly imprinted polymers (MIPs) were synthesized using tylosin as a template and methacrylic acid as a functional monomer. Samples were extracted with sodium borate buffer solution and ethyl acetate, and purified by the MIP cartridge. The results showed that the cartridge exhibited good recognition performance for macrolides, and better purification effect than the traditional solid-phase extraction cartridges. Recoveries of analytes at three spiking levels 1, 5 and 20μgkg(-1) ranged from 60.7% to 100.3% with the relative standard deviations less than 14%. The limits of detection of the method were between 0.1 and 0.4μgkg(-1). The method is useful for the routine monitoring of the residues of macrolide drugs in animal muscles. PMID:27132837

  20. Characterization of particle morphology of biochanin A molecularly imprinted polymers and their properties as a potential sorbent for solid-phase extraction.

    PubMed

    Chrzanowska, Anna M; Poliwoda, Anna; Wieczorek, Piotr P

    2015-04-01

    Molecularly imprinted polymers (MIPs) with biochanin A as a template were obtained using a bulk polymerization with non-covalent imprinting approach. The polymers were prepared in acetonitrile as porogen, using ethylene glycol dimethacrylate (EDMA) as cross-linking agent. The synthesis, with an application of 1',1'-azobis(cyclohexanecarbonitrile) (ACHN) as an initiator, has been performed thermally. During the synthesis process the effect of different functional monomers such as methacrylic acid (MAA), acrylamide (AA) and 4-vinylpyridine (4-VP) was investigated. The application of nitrogen sorption porosimetry, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) permitted the characterization and evaluation of synthesized polymers. The adsorption capacity of obtained MIPs was checked by using the binding testing. All synthesized polymers were evaluated as solid-phase extraction (SPE) sorbents for isolation and preconcentration of biochanin A and its analogues, daidzein and genistein. The MIPs exhibited higher affinity for biochanin A over competitive compounds. PMID:25687010

  1. Molecularly imprinted polymer on a SiO2 -coated graphene oxide surface for the fast and selective dispersive solid-phase extraction of Carbamazepine from biological samples.

    PubMed

    Khalilian, Faezeh; Ahmadian, Setareh

    2016-04-01

    A surface carbamazepine-imprinted polymer was grafted and synthesized on the SiO2 /graphene oxide surface. Firstly SiO2 was coated on synthesized graphene oxide sheet using the sol-gel technique. Prior to polymerization, the vinyl group was incorporated on to the surface of SiO2 /graphene oxide to direct selective polymerization on the surface. Methacrylic acid, ethylene glycol dimethacrylate and ethanol were used as monomer, cross-linker and porogen, respectively. Nonimprinted polymer was also prepared for comparison. The properties of the molecularly imprinted polymer were characterized using field-emission scanning electron microscopy and Fourier-transform infrared spectroscopy. The surface molecularly imprinted polymer was utilized as an adsorbent of dispersive solid-phase extraction for separation and preconcentration of carbamazepine. The effects of the different parameters influencing the extraction efficiency, such as sample pH were investigated and optimized. The specificity of the molecular imprinted polymer over the nonimprinted polymer was examined in absence and presence of competitive drugs. The carbamazepine calibration curve showed linearity in the ranges 0.5-500 μg/L. The limits of detection and quantification under the optimized conditions were 0.1 and 0.3 μg/L, respectively. The within-day and between-day relative standard deviations (n = 3) were 3.6 and 4.3%, respectively. Furthermore, the relative recoveries for spiked biological samples were above 85%. PMID:26899307

  2. Molecularly imprinted polymers for the solid-phase extraction of four fluoroquilones from milk and lake water samples.

    PubMed

    Wu, Xi; Wu, Lintao

    2015-10-01

    A method based on molecular crowding and ionic liquids as reaction solvents has been used for the synthesis of molecularly imprinted polymers. Levofloxacin was selected as the template, polymethyl methacrylate was the molecular crowding agent, and 1-butyl-3-methylimidazolium tetrafluoroborate (ionic liquid) was selected as the reaction solvent and porogen. The optimized proportion for the mixed porogen was dimethyl sulfoxide/ionic liquid/polymethyl methacrylate 1:1.6:5 in chloroform (150 mg mL(-1) ). The morphology and chemical composition of levofloxacin imprinted polymers were assessed by scanning electron microscopy and Fourier transform infrared spectroscopy. The absorption experiments demonstrated that the levofloxacin imprinted polymers possess high selective recognition property to levofloxacin and analogs, including enrofloxacin, ciprofloxacin and gatifloxacin, which all belong to fluoroquinolones. An extraction method using levofloxacin imprinted polymers as sorbent followed by high-performance liquid chromatography analysis was optimized for the determination of four fluoroquinolones in milk and lake water samples. Under the optimized conditions, good linearity was observed in a range of 5-1000 ng g(-1) with the limit of detection between 0.3 and 0.5 ng g(-1) for the four fluoroquinolones. The recoveries at three spiked levels ranged 82.4-98.3% with the relative standard deviation ≤4.9. PMID:26418224

  3. A new ion imprinted polymer based on Ru(III)-thiobarbituric acid complex for solid phase extraction of ruthenium(III) prior to its determination by ETAAS.

    PubMed

    Zambrzycka, Elżbieta; Godlewska-Żyłkiewicz, Beata

    2014-01-01

    A new ruthenium ion imprinted polymer was prepared from the Ru(III) 2-thiobarbituric acid complex (the template), methacrylic acid or acrylamide (the functional monomers), and ethylene glycol dimethacrylate (the cross-linking agent) using 2,2'-azobisisobutyronitrile as the radical initiator. The ion imprinted polymer was characterized and used as a selective sorbent for the solid phase extraction of Ru(III) ions. The effects of type of functional monomer, sample volume, solution pH and flow rate on the extraction efficiency were studied in the dynamic mode. Ru(III) ion was quantitatively retained on the sorbents in the pH range from 3.5 to 10, and can be eluted with 4 mol L(-1) aqueous ammonia. The affinity of Ru(III) for the ion imprinted polymer based on the acrylamide monomer is weaker than that for the polymer based on the methacrylic acid monomer, which therefore was used in interference studies and in analytical applications. Following extraction of Ru(III) ions with the imprint and their subsequent elution from the polymer with aqueous ammonia, Ru(III) was detected by electrothermal atomic absorption spectrometry with a detection limit of 0.21 ng mL(-1). The method was successfully applied to the determination of trace amounts of Ru(III) in water, waste, road dust and platinum ore (CRM SARM 76) with a reproducibility (expressed as RSD) below 6.4 %. FigureThe new ion imprinted polymer was prepared and used for the separation of ruthenium from water and most complex environmental samples, such as road dust and platinum ore (CRM SARM 76) prior ETAAS determination. PMID:24966442

  4. Molecularly Imprinted Dispersive Solid-Phase Extraction for the Determination of Triazine Herbicides in Grape Seeds by High-Performance Liquid Chromatography.

    PubMed

    Li, Xinpei; Wang, Yuanpeng; Sun, Qun; Xu, Bo; Yang, Zhaoqing; Wang, Xinghua

    2016-05-01

    Molecular imprinting technique, regarded as one of the current state-of-the-art researches, was incorporated with the simple dispersive solid-phase extraction (MI-DSPE) in this work for the extraction of triazine herbicides in grape seeds. The atrazine molecularly imprinted polymers (MIPs) were successfully prepared and characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. The imprinting particles were used as the adsorbent in DSPE. Thus, a simple, rapid and selective method based on MIPs coupled with DSPE was established for the simultaneous cleaning-up and quantitative extraction of four triazine herbicides in grape seeds. The experiment parameters, including type of washing solvents, washing time and type of eluting solvents, were investigated and optimized. The performance of the present method was validated by high-performance liquid chromatography. Good linear responses were obtained in concentration range of 0.010-5.0 µg g(-1)with correlation coefficients (r(2)) higher than 0.9993. The recoveries at two spiked levels (1.0 and 2.0 µg g(-1)) were between 81.2 and 113.0% with relative deviations ranging from 1.2 to 10.7%. The limits of detection were ranged between 0.006 and 0.013 µg g(-1), which were lower than the values required by European regulations. PMID:27013667

  5. Molecularly imprinted coated graphene oxide solid-phase extraction monolithic capillary column for selective extraction and sensitive determination of phloxine B in coffee bean.

    PubMed

    Zhai, Haiyun; Su, Zihao; Chen, Zuanguang; Liu, Zhenping; Yuan, Kaisong; Huang, Lu

    2015-03-20

    A method was developed to sensitively determine phloxine B in coffee bean by molecularly imprinted polymers (MIPs) coated graphene oxide (GO) solid-phase extraction (GO-MISPE) coupled with high-performance liquid chromatography and laser-induced fluorescence detection (HPLC-LIF). The GO-MISPE capillary monolithic column was prepared by water-bath in situ polymerization, using GO as supporting material, phloxine B, methacrylic acid (MAA), and ethylene dimethacrylate (EDMA) as template, functional monomer, and cross-linker, respectively. The properties of the homemade GO-MISPE capillary monolithic column, including capacity and specificity, were investigated under optimized conditions. The GO-MIPs were characterized by scanning electron microscopy (SEM) and Fourier transform-infrared spectroscopy (FT-IR). The mean recoveries of phloxine B in coffee bean ranged from 89.5% to 91.4% and the intra-day and inter-day relative standard deviation (RSD) values all ranged from 3.6% to 4.7%. Good linearity was obtained over 0.001-2.0 μg mL(-1) (r=0.9995) with the detection limit (S/N=3) of 0.075 ng mL(-1). Under the selected conditions, enrichment factors of over 90-fold were obtained and extraction on the monolithic column effectively cleaned up the coffee bean matrix. The results demonstrated that the proposed GO-MISPE HPLC-LIF method can be applied to sensitively determine phloxine B in coffee bean. PMID:25732580

  6. A (-)-norephedrine-based molecularly imprinted polymer for the solid-phase extraction of psychoactive phenylpropylamino alkaloids from Khat (Catha edulis Vahl. Endl.) chewing leaves.

    PubMed

    Atlabachew, Minaleshewa; Torto, Nelson; Chandravanshi, Bhagwan Singh; Redi-Abshiro, Mesfin; Chigome, Samuel; Mothibedi, Kediemetse; Combrinck, Sandra

    2016-07-01

    A molecularly imprinted polymer (MIP) was prepared using (-)-norephedrine as the template, methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the cross-linker and chloroform as the porogen. The MIP was used as a selective sorbent in the molecularly imprinted solid-phase extraction (MIP-SPE) of the psychoactive phenylpropylamino alkaloids, norephedrine and its analogs, cathinone and cathine, from Khat (Catha edulis Vahl. Endl.) leaf extracts prior to HPLC-DAD analysis. The MIP was able to selectively extract the alkaloids from the aqueous extracts of Khat. Loading, washing and elution of the alkaloids bound to the MIP were evaluated under different conditions. The clean baseline of the Khat extract obtained after MIP-SPE confirmed that a selective and efficient sample clean-up was achieved. Good recoveries (90.0-107%) and precision (RSDs 2.3-3.2%) were obtained in the validation of the MIP-SPE-HPLC procedure. The content of the three alkaloids in Khat samples determined after treatment with MIP-SPE and a commercial Isolute C18 (EC) SPE cartridge were in good agreement. These findings indicate that MIP-SPE is a reliable method that can be used for sample pre-treatment for the determination of Khat alkaloids in plant extracts or similar matrices and could be applicable in pharmaceutical, forensic and biomedical laboratories. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26531856

  7. Analysis of benzo[a]pyrene in vegetable oils using molecularly imprinted solid phase extraction (MISPE) coupled with enzyme-linked immunosorbent assay (ELISA).

    PubMed

    Pschenitza, Michael; Hackenberg, Rudolf; Niessner, Reinhard; Knopp, Dietmar

    2014-01-01

    This paper describes the development of a molecularly imprinted polymer-based solid phase extraction (MISPE) method coupled with enzyme-linked immunosorbent assay (ELISA) for determination of the PAH benzo[a]pyrene (B[a]P) in vegetable oils. Different molecularly imprinted polymers (MIPs) were prepared using non-covalent 4-vinylpyridine/divinylbenzene co-polymerization at different ratios and dichloromethane as porogen. Imprinting was done with a template mixture of phenanthrene and pyrene yielding a broad-specific polymer for PAHs with a maximum binding capacity (Q) of ~32 μg B[a]P per 50 mg of polymer. The vegetable oil/n-hexane mixture (1:1, (v/v)) was pre-extracted with acetonitrile, the solvent evaporated, the residue reconstituted in n-hexane and subjected to MISPE. The successive washing with n-hexane and isopropanol revealed most suitable to remove lipid matrix constituents. After elution of bound PAHs from MISPE column with dichloromethane, the solvent was evaporated, the residue reconstituted with dimethyl sulfoxide and diluted 100-fold with methanol/water (10:90, (v/v)) for analysis of B[a]P equivalents with an ELISA. The B[a]P recovery rates in spiked vegetable oil samples of different fatty acid composition were determined between 63% and 114%. The presence of multiple PAHs in the oil sample, because of MIP selectivity and cross-reactivity of the ELISA, could yield overestimated B[a]P values. PMID:24887045

  8. Determination of Phenolic Compounds in Environmental Water by HPLC Combination with On-Line Solid-Phase Extraction Using Molecularly Imprinted Polymers.

    PubMed

    Qiu, Xiu-Zhen; Liang, Yong; Guo, Hui-Shi; Wang, Xiao-Bing; Lin, Chuang-Xin

    2015-12-01

    A novel molecularly imprinted polymer (MIP) was synthesized using halloysite nanotubes (HNT) as matrix, β-cyclodextrin (β-CD) and methyl propyl acid (MAA) as functional monomers, and 2,4,6-TCP as template molecule by graft copolymerization. Infrared spectroscopy and transmission electron microscopy (TEM) were used to characterize the as-synthesized imprinted polymer. The selective recognizability of the MIP towards four phenolic analogs were determined and the recognition coefficients for 2,4,6-TCP, 2,6-DCP, 4-CP and phenol were found to be 2.17, 1.85, 2.02 and 1.36, respectively. Using as the packing material of solid-phase extraction, the imprinted polymer has been applied to on-line extraction of the four phenolic compounds in environmental water. The corresponding analytical methods to determine these four phenolic compounds have been developed. Good linear relationships were obtained over the range of 0.05-5.0 mg x L(-1). The average recoveries for spiked samples were in the range of 74.8-97.2%, and the detection limits for 2,4,6-TCP, 2,6-DCP, p-chlorophenol, phenol were 0.19, 0.20, 0.75, 0.73 mg x L(-1), respectively. The method is rapid, accurate and high selectivity. It was feasible for the determination of trace level phenolic compounds in environmental samples. PMID:26682381

  9. Highly class-selective solid-phase extraction of bisphenols in milk, sediment and human urine samples using well-designed dummy molecularly imprinted polymers.

    PubMed

    Sun, Xiaoli; Wang, Jincheng; Li, Yun; Jin, Jing; Yang, Jiajia; Li, Fang; Shah, Syed Mazhar; Chen, Jiping

    2014-09-19

    Dummy molecularly imprinted polymers (DMIPs) towards bisphenols (BPs) were prepared employing 1,1,1-tris(4-hydroxyphenyl)ethane (THPE) and phenolphthalein (PP) as dummy templates. The selectivity of the resulting DMIPs was evaluated by high-performance liquid chromatography (HPLC). Both PP-DMIP and THPE-DMIP showed excellent class selectivity towards bisphenols. THPE-DMIP prepared using the template molecule with three hydroxyphenyl functionalities achieved higher imprinting factors (IF) for the bisphenols over a range of 7.9-19.8. An efficient approach based on dummy molecularly imprinted solid phase extraction (DMISPE) coupled with HPLC-DAD was developed for selective extraction of eight bisphenols in sediment, milk and human urine samples using THPE-DMIP as sorbents. The method showed good recoveries (82-102%) and precision (RSD 0.2-4%, n=3) for these samples spiked at two concentration levels (25 and 250ngg(-1) or ngmL(-1)). The detection limits ranged between 0.6 and 1.1ngg(-1) or ngmL(-1). Efficient removal of sample matrix and interferences was also achieved for these samples after DMISPE process. The results demonstrated great potential of the optimized methods for sample preparation in the routine analysis of trace BPs in complex samples. PMID:25130092

  10. Selective trace enrichment of acidic pharmaceuticals in real water and sediment samples based on solid-phase extraction using multi-templates molecularly imprinted polymers.

    PubMed

    Duan, Yan-Ping; Dai, Chao-Meng; Zhang, Ya-Lei; Ling-Chen

    2013-01-01

    A novel multi-templates molecularly imprinted polymer (MIP), using acidic pharmaceuticals mixture (ibuprofen (IBP), naproxen (NPX), ketoprofen (KEP), diclofenac (DFC), and clofibric acid (CA)) as the template, was prepared as solid-phase extraction (SPE) material for the quantitative enrichment of acidic pharmaceuticals in environmental samples and off-line coupled with liquid chromatography-mass spectrometry (LC/MS/MS). Washing solvent was optimized in terms of kind and volume for removing the matrix constituents nonspecifically adsorbed on the MIP. When 1L of water sample spiked at 1μg/L was loaded onto the cartridge, the binding capacity of the MIP cartridge were 48.7μg/g for KEP, 60.7μg/g for NPX, 52μg/g for CA, 61.3μg/g for DFC and 60.7μg/g for IBP, respectively, which are higher than those of the commercial single template MIP in organic medium (e.g. toluene) reported in the literature. Recoveries of the five acidic pharmaceuticals extracted from 1L of real water samples such as lake water and wastewater spiked at 1μg/L were more than 95%. The recoveries of acidic pharmaceuticals extracted from 10-g sediment sample spiked at the 10ng/g level were in the range of 77.4-90.6%. To demonstrate the potential of the MIP obtained, a comparison with commercial C18 SPE cartridge was performed. Molecularly imprinted solid-phase extraction (MISPE) cartridge showed higher recoveries than commercial C18 SPE cartridge for acidic pharmaceuticals. These results showed the suitability of the MISPE method for the selective extraction of a group of structurally related compounds such as acidic pharmaceuticals. PMID:23245900

  11. Supported liquid membrane-protected molecularly imprinted beads for the solid phase micro-extraction of triazines from environmental waters.

    PubMed

    Turiel, E; Díaz-Álvarez, M; Martín-Esteban, A

    2016-02-01

    In this work, a novel methodology based on the combination of MIP technology with micro solid-phase extraction in a hollow fibre device for the trace enrichment and cleanup of triazines in environmental waters is described. All parameters affecting both migration of triazines from samples to the lumen of the fibre and rebinding into MIP sites have been carefully optimized. Final conditions included, addition of 20% NaCl to the sample to produce salting-out effect, extraction of analytes during 45min with orbital stirring at 750rpm, and then washing the fibre with toluene during 5min to allow selective recognition of triazines before elution in HPLC inserts containing 450μL of a methanol/acetic acid mixture (95/5, v/v). Under optimum conditions, quantitative recoveries for simazine, cyanazine, atrazine, propazine and terbutylazine, were achieved both in surface, ground and tap water samples, with relative standard deviations lower than 10.6%, and limits of detection in the low ngL(-1) concentration level. PMID:26777780

  12. Analysis of testosterone in human urine using molecularly imprinted solid-phase extraction and corona discharge ion mobility spectrometry.

    PubMed

    Mirmahdieh, Shiva; Mardihallaj, Azam; Hashemian, Zahra; Razavizadeh, Jalal; Ghaziaskar, Hassan; Khayamian, Taghi

    2011-01-01

    Analysis of testosterone was accomplished using corona discharge ion mobility spectrometry. Molecular imprinted polymer was used for the extraction and pre-concentration of testosterone. Analytical parameters including precision, dynamic range and detection limit were obtained. The linear dynamic range was from 10 to 250 ng/mL and the limit of detection was 0.9 ng/mL. The proposed method was used for analysis of testosterone in urine samples. A urine sample from a 3-year-old girl was used as the blank. The RSD was below 10%. The obtained results from the method were also compared with the standard method for analysis of testosterone using SPE-HPLC analysis. The results demonstrate the accuracy of the method. PMID:21171183

  13. Preparation and evaluation of a novel molecularly imprinted polymer coating for selective extraction of indomethacin from biological samples by electrochemically controlled in-tube solid phase microextraction.

    PubMed

    Asiabi, Hamid; Yamini, Yadollah; Seidi, Shahram; Ghahramanifard, Fazel

    2016-03-24

    In the present work, an automated on-line electrochemically controlled in-tube solid-phase microextraction (EC-in-tube SPME) coupled with HPLC-UV was developed for the selective extraction and preconcentration of indomethacin as a model analyte in biological samples. Applying an electrical potential can improve the extraction efficiency and provide more convenient manipulation of different properties of the extraction system including selectivity, clean-up, rate, and efficiency. For more enhancement of the selectivity and applicability of this method, a novel molecularly imprinted polymer coated tube was prepared and applied for extraction of indomethacin. For this purpose, nanostructured copolymer coating consisting of polypyrrole doped with ethylene glycol dimethacrylate was prepared on the inner surface of a stainless-steel tube by electrochemical synthesis. The characteristics and application of the tubes were investigated. Electron microscopy provided a cross linked porous surface and the average thickness of the MIP coating was 45 μm. Compared with the non-imprinted polymer coated tubes, the special selectivity for indomethacin was discovered with the molecularly imprinted coated tube. Moreover, stable and reproducible responses were obtained without being considerably influenced by interferences commonly existing in biological samples. Under the optimal conditions, the limits of detection were in the range of 0.07-2.0 μg L(-1) in different matrices. This method showed good linearity for indomethacin in the range of 0.1-200 μg L(-1), with coefficients of determination better than 0.996. The inter- and intra-assay precisions (RSD%, n = 3) were respectively in the range of 3.5-8.4% and 2.3-7.6% at three concentration levels of 7, 70 and 150 μg L(-1). The results showed that the proposed method can be successfully applied for selective analysis of indomethacin in biological samples. PMID:26944991

  14. Highly sensitive determination of cyromazine, melamine, and their metabolites in milk by molecularly imprinted solid-phase extraction combined with ultra-performance liquid chromatography.

    PubMed

    Ge, Xusheng; Wu, Xingqiang; Wang, Junmin; Liang, Shuxuan; Sun, Hanwen

    2015-04-01

    A novel molecularly imprinted solid-phase extraction-ultra-performance liquid chromatography (MISPE-UPLC) method for effective separation and simultaneous determination of cyromazine, melamine, and their metabolites (ammeline and ammelide) in milk samples was developed. Molecularly imprinted polymers (MIP) were synthesized in an ethanol-water system, with melamine as the template and methacrylic acid as the organic functional monomer. The MIP were applied as a specific sorbent for the selective solid phase extraction of cyromazine, ammelide, melamine and ammeline. The molecular recognition mechanism was investigated by molecular simulation and the experiment was validate by using Fourier transform infrared spectroscopy and (1)H nuclear magnetic resonance spectroscopy. A new mechanism based on the formation of both an amido group and hydrogen bonds was developed. A binding study demonstrated that the MIP showed excellent affinity to and high selectivity for melamine and related compounds. Under optimized conditions, we achieved good linearity of the calibration curves with correlation coefficients >0.999. Low limits of quantification (LOQ) for the method were determined to be 1.25, 1.25, 2.59, and 6.42 µg/kg for cyromazine, ammelide, melamine, and ammeline, respectively, which were 3 orders of magnitude smaller than the maximum residue limit (MRL). The high sensitivity of this method allows detection at the microgram per kilogram level. The proposed MISPE-UPLC method is a highly selective and sensitive method for determination of cyromazine, melamine, and their metabolites (ammeline and ammelide) for use in the control and quality assurance of milk. PMID:25682136

  15. Water-compatible dummy molecularly imprinted resin prepared in aqueous solution for green miniaturized solid-phase extraction of plant growth regulators.

    PubMed

    Wang, Mingyu; Chang, Xiaochen; Wu, Xingyu; Yan, Hongyuan; Qiao, Fengxia

    2016-08-01

    A water-compatible dummy molecularly imprinted resin (MIR) was synthesized in water using melamine, urea, and formaldehyde as hydrophilic monomers of co-polycondensation. A triblock copolymer (PEO-PPO-PEO, P123) was used as porogen to dredge the network structure of MIR, and N-(1-naphthyl) ethylenediamine dihydrochloride, which has similar shape and size to the target analytes, was the dummy template of molecular imprinting. The obtained MIR was used as the adsorbent in a green miniaturized solid-phase extraction (MIR⬜mini-SPE) of plant growth regulators, and there was no organic solvent used in the entire MIR⬜mini-SPE procedure. The calibration linearity of MIR⬜mini-SPE⬜HPLC method was obtained in a range 5⬜250ngmL(↙1) for IAA, IPA, IBA, and NAA with correlation coefficient (r) Ⱕ0.9998. Recoveries at three spike levels are in the range of 87.6⬜100.0% for coconut juice with relative standard deviations Ⱔ8.1%. The MIR⬜mini-SPE method possesses the advantages of environmental friendliness, simple operation, and high efficiency, so it is potential to apply the green pretreatment strategy to extraction of trace analytes in aqueous samples. PMID:27378249

  16. Computational Aided-Molecular Imprinted Polymer Design for Solid Phase Extraction of Metaproterenol from Plasma and Determination by Voltammetry Using Modified Carbon Nanotube Electrode

    PubMed Central

    Ahmadi, Farhad; Karamian, Ehsan

    2014-01-01

    A molecular imprinted polymer (MIP) was computationally designed and synthesized for the selective extraction of metaproterenol (MTP), from human plasma. In this regards semi empirical MP3 and mechanical quantum (DFT) calculations were used to find a suitable functional monomers. On the basis of computational and experimental results, acrylic acid (AA) and DMSO:MeOH (90:10 %V/V) were found to be the best choices of functional monomer and polymerization solvents, respectively. This polymer was then used as a selective sorbent to develop a molecularly imprinted solid-phase extraction (MISPE) procedure followed by differential pulse voltammetry by using modified carbon nanotube electrode. The analysis was performed in phosphate buffer, pH 7.0. Peak currents were measured at +0.67 V versus Ag/AgCl. The linear calibration range was 0.026–8.0 μg mL-1 with a limit of detection 0.01 μg mL-1. The relative standard deviation at 0.5 μg mL-1 was 4.76% (n=5). The mean recoveries of 5 μg mL-1 MTP from plasma was 92.2% (n=5). The data of MISPE-DPV were compared with the MISPE-HPLC-UV. Although, the MISPE-DPV was more sensitive but both techniques have similar accuracy and precision. PMID:25237337

  17. Rapid analysis of ractopamine in pig tissues by dummy-template imprinted solid-phase extraction coupling with surface-enhanced Raman spectroscopy.

    PubMed

    Xiao, Xiaohua; Yan, Kuanglin; Xu, Xianfang; Li, Gongke

    2015-06-01

    Ritodrine has similar skeleton structure to ractopamine and it was selected as the dummy-template molecule to synthesize the molecular imprinted polymers (MIPs). The MIPs exhibited better selectivity to ractopamine than to the dummy-template molecule: the imprint factor for ractopamine was 8.9, while 7.6 for ritodrine. The MIPs were used as sorbents in solid-phase extraction for selective enrichment of ractopamine, and some key parameters were optimized. After that, a rapid surface-enhanced Raman spectroscopy method was developed for analysis of ractopamine and isoxuprine in pig tissue samples. Under the optimal conditions, good linearity was achieved in the range of 20.0-200.0 μg/L for ractopamine and isoxsuprine at 842 cm(-1) and 993 cm(-1), respectively. The limits of detection were 3.1-4.3 μg/L, which were lower than the maximum allowed by U. S. Food and Drug Administration. The recoveries of ractopamine and isoxsuprine were 72.4-79.7% and 71.0-78.2% for the spiked pork and pig liver, respectively, while the relative standard deviations ranging from 7.4% to 13.0%. The results suggest that the proposed method is sensitive and selective, and it has good potential on the quantitative analysis of trace amounts of β-agonists in complex samples. PMID:25863369

  18. Identification of the nitroaromatic explosives in post-blast samples by online solid phase extraction using molecularly imprinted silica sorbent coupled with reversed-phase chromatography.

    PubMed

    Lordel-Madeleine, Sonia; Eudes, Véronique; Pichon, Valérie

    2013-06-01

    In a previous work, a molecularly imprinted silica (MIS) sorbent was synthesized for the selective extraction of nitroaromatic explosives from real samples. This MIS packed in a cartridge was used for an off-line solid phase extraction procedure mainly based on hydrophobic and π-π interactions. In this work, the MIS was packed in a precolumn to be connected online with a reversed-phase LC system and a diode array detector. For this, the chromatographic conditions were first studied to obtain the separation of 1,3-dinitrobenzene, 1,3,5-trinitrobenzene, 2,4-dinitrotoluene, 2,6-dinitrotoluene, 2,4,6-trinitrotoluene, and tetryl. An optimized procedure dedicated to the selective treatment of aqueous samples was then developed with the MIS for the simultaneous extraction of the nitroaromatic compounds commonly used as explosives. Finally, the four nitrotoluenes were selectively extracted and determined simultaneously with extraction recoveries higher than 90% using the online device composed of the MIS coupled with a diphenyl chromatographic column. The potential of this sorbent was highlighted by its use for the cleanup of simulated post-blast samples. PMID:23568612

  19. Molecularly imprinted polymer-sol-gel tablet toward micro-solid phase extraction: I. Determination of methadone in human plasma utilizing liquid chromatography-tandem mass spectrometry.

    PubMed

    El-Beqqali, Aziza; Abdel-Rehim, Mohamed

    2016-09-14

    In the present work molecularly imprinted sol-gel tablet (MIP-Tablet) was prepared. The MIP-sol-gel was prepared as a thin layer on polyethylene material in a tablet form. Methadone-d9 was selected as the template and 3-(propylmethacrylate)-trimethoxysilane was used as precursor. MIP-Tablet was applied for micro-solid phase extraction (μ-SPE). The MIP-Tablet was used for the determination of methadone in human plasma samples utilizing liquid chromatography-tandem mass spectrometry; and each tablet could be used twenty times. The extraction time was 10 min while desorption time was 6 min. Factors affecting the extraction efficiency such as desorption solvents, sample pH, salt addition, extraction time, desorption time and adsorption capacity were investigated. The calibration curves were obtained within the range of 5-5000 ng/mL using methadone in human plasma samples. The coefficients of determination (r(2)) values were ≥0.999 for all runs and the extraction recovery was >80%. The accuracy values for quality control samples varied from +3.6 to +9.7% and the inter-day precision (RSD %) values were ranged from 5.0 to 8.0%. The limit of detection was 1.0 ng/mL and the lower limit of quantification was 5 ng/mL utilizing methadone in human plasma samples. PMID:27566346

  20. Molecularly imprinted solid phase extraction in a syringe filter for determination of triazine herbicides in Radix Paeoniae Alba by ultra-fast liquid chromatography.

    PubMed

    Li, Xinpei; Wang, Yuanpeng; Sun, Qun; Xu, Bo; Yu, Yong; Wang, Xinghua

    2016-02-01

    A novel, cost-effective and simple solid phase extraction (SPE) method, by using a syringe connected with a nylon membrane filter as the adsorbent container, was developed for the extraction of triazine herbicides from Radix Paeoniae Alba (RPA) samples. The selective molecularly imprinted polymers (MIPs) synthesized with the template of atrazine were employed as the adsorbents for the enrichment and purification of analytes. The extraction parameters, including the volume and type of loading solvent, the type of washing solvent and eluting solvent, were investigated. Under the optimized conditions, the final extracts were analyzed by ultra-fast liquid chromatography (UFLC). Recoveries of the developed method range from 92.4% to 107.3% with intra- and inter-day relative standard deviations (RSDs) lower than 8.2%. The calibration curve is linear in the concentration range of 0.005-2.4 µg g(-1) for desmetryn, atrazine and terbumeton, and 0.005-1.5 µg g(-1) for dimethametryn and dipropetryn, with the correlation coefficient (R(2)) higher than 0.9995. The limits of detection (LODs) of five triazine herbicides are in the range of 0.09-0.39 ng g(-1), which are lower than the maximum residue levels (MRLs) established by various official organizations. Analytical results of three real Radix Paeoniae Alba samples indicate that the proposed method is cost-effective and easy-to-use than other routine pretreatment methods. PMID:26653483

  1. Solid Phase Micro Extraction (SPME)

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Internation Flavors and Fragrances Inc. proprietary research technology, Solid Phase Micro Extraction (SPME) utilizes a special fiber needle placed directly next to the bloom of the living flower to collect the fragrance molecules. SPME was used in the Space Flower experiment aboard STS-95 space shuttle mission, after which Dr. Braja Mookherjee (left) and Subha Patel of IFF will analyze the effects of gravity on the Overnight Scentsation rose plant.

  2. Molecularly imprinted polymers grafted to flow through poly(trimethylolpropane trimethacrylate) monoliths for capillary-based solid-phase extraction.

    PubMed

    Courtois, Julien; Fischer, Gerd; Sellergren, Börje; Irgum, Knut

    2006-03-17

    Monolithic molecularly imprinted polymers (mMIPs) have been synthesized in a novel way using a trimethylolpropane trimethacrylate core material photo-polymerized in situ in a 100 microm I.D. UV-transparent capillary and further photo-grafted to create specific cavities in the grafted layer. This polymerization technique allows the imprints to be directly created on the surface of the material using a minimum amount of template. Three different anaesthetics of similar structures (bupivacaine, mepivacaine and S-ropivacaine) were used as model target molecules to synthesize sample enrichment media. Hence, various mMIPs have been prepared and evaluated on a micro-system against each analyte in order to test the retention properties and cross-selectivities of the materials. The retention factors were determined and compared with the non-imprinted reference column (mNIP), yielding high imprinting factors together with good selectivity factors between the three analytes. A study with a pure enantiomeric target was carried out to assess the degree of stereo-specific imprinting for injection of racemic mixtures. Finally, one column was imprinted with an equimolar mixture of all three anaesthetics to provide further comprehension of the retention mechanism and accredit the possibility of using the material as a sample enrichment entity. Scanning electron microscopy (SEM), nitrogen absorption/desorption (BET) and mercury intrusion porosimetry were used to characterize the monolith and the mMIPs properties. Nuclear magnetic resonance (NMR) has been used to assess the similarities between the mMIP and mNIP. PMID:16376897

  3. Novel ion imprinted magnetic mesoporous silica for selective magnetic solid phase extraction of trace Cd followed by graphite furnace atomic absorption spectrometry detection

    NASA Astrophysics Data System (ADS)

    Zhao, Bingshan; He, Man; Chen, Beibei; Hu, Bin

    2015-05-01

    Determination of trace Cd in environmental, biological and food samples is of great significance to toxicological research and environmental pollution monitoring. While the direct determination of Cd in real-world samples is difficult due to its low concentration and the complex matrix. Herein, a novel Cd(II)-ion imprinted magnetic mesoporous silica (Cd(II)-II-MMS) was prepared and was employed as a selective magnetic solid-phase extraction (MSPE) material for extraction of trace Cd in real-world samples followed by graphite furnace atomic absorption spectrometry (GFAAS) detection. Under the optimized conditions, the detection limit of the proposed method was 6.1 ng L- 1 for Cd with the relative standard deviation (RSD) of 4.0% (c = 50 ng L- 1, n = 7), and the enrichment factor was 50-fold. To validate the proposed method, Certified Reference Materials of GSBZ 50009-88 environmental water, ZK018-1 lyophilized human urine and NIES10-b rice flour were analyzed and the determined values were in a good agreement with the certified values. The proposed method exhibited a robust anti-interference ability due to the good selectivity of Cd(II)-II-MMS toward Cd(II). It was successfully employed for the determination of trace Cd(II) in environmental water, human urine and rice samples with recoveries of 89.3-116%, demonstrating that the proposed method has good application potential in real world samples with complex matrix.

  4. Porous membrane-protected molecularly imprinted polymer micro-solid-phase extraction for analysis of urinary cocaine and its metabolites using liquid chromatography - Tandem mass spectrometry.

    PubMed

    Sánchez-González, Juan; Tabernero, María Jesús; Bermejo, Ana María; Bermejo-Barrera, Pilar; Moreda-Piñeiro, Antonio

    2015-10-22

    Porous membrane-protected micro-solid phase extraction (μ-SPE) using a molecularly imprinted polymer (MIP) as an adsorbent has been proposed as an integrated extraction-cleanup procedure for isolating cocaine (COC) and its metabolites [benzoylecgonine (BZE), ecgonine methyl ester (EME), and cocaethylene (CE)] from human urine. MIP beads have been synthesized using COC as a template molecule, ethylene dimethacrylate (EDMA) as a functional monomer, divinylbenzene (DVB) as a cross-linker, and 2,2'-azobisisobutyronitrile (AIBN) as an initiator. High performance liquid chromatography - tandem mass spectrometry (HPLC-MS/MS) has been used for quantifying the analytes after MIP-μ-SPE. Variables such as urine pH, adsorption temperature and time, mechanical (orbital-horizontal) stirring; and composition of the eluting solution and eluting time, were evaluated. The proposed method was shown to be precise and accurate [relative standard deviations (RSDs) of intra- and inter-day tests ranging from 3 to 8% and from 2 to 10%, respectively]; and analytical recoveries in the range of 89-100%). In addition, excellent accuracy was also verified after analyzing a FDT +25% control material for BZE. The detection limits were in the range of 0.16-1.7 ng L(-1), low enough for confirmative conclusions regarding cocaine abuse. The method was finally applied for screening/quantifying cocaine and metabolites in urine samples from poly-drug abusers. PMID:26526910

  5. Efficient determination of protocatechuic acid in fruit juices by selective and rapid magnetic molecular imprinted solid phase extraction coupled with HPLC.

    PubMed

    Xie, Lianwu; Guo, Junfang; Zhang, Yuping; Shi, Shuyun

    2014-08-13

    Magnetic molecular imprinted polymers (MMIPs) have been prepared as solid phase material to selectively extract protocatechuic acid (PCA) from fruit juices with high capacity and fast binding kinetics. The resulting MMIPs were characterized by TEM, FT-IR, TGA, and VSM. The adsorption process between PCA and MMIPs followed Langumuir adsorption isotherm with maximum adsorption capacity at 7.5 mg/g and pseudo-second-order reaction kinetics with fast binding kinetics (equilibrium time at 40 min). In addition, the prepared MMIPs showed rapid magnetic separation (10 s) and reusability (retained 94.9% after six cycles). Subsequently, MMIPs were successfully applied for selective enrichment and determination of PCA from fruit juices (0.45 μg/mL in grape juice but not detected in apple juice, pineapple juice, orange juice, and peach juice) with satisfactory recoveries (92-107%). The results indicated that synthesized MMIPs can be used for efficient and selective extraction of PCA from complex matrices. PMID:25075753

  6. Selective Solid-Phase Extraction of Zinc(II) from Environmental Water Samples Using Ion Imprinted Activated Carbon.

    PubMed

    Moniri, Elham; Panahi, Homayon Ahmad; Aghdam, Khaledeh; Sharif, Amir Abdollah Mehrdad

    2015-01-01

    A simple ion imprinted amino-functionalized sorbent was synthesized by coupling activated carbon with iminodiacetic acid, a functional compound for metal chelating, through cyanoric chloride spacer. The resulting sorbent has been characterized using FTIR spectroscopy, elemental analysis, and thermogravimetric analysis and evaluated for the preconcentration and determination of trace Zn(II) in environmental water samples. The optimum pH value for sorption of the metal ion was 6-7.5. The sorption capacity of the functionalized sorbent was 66.6 mg/g. The chelating sorbent can be reused for 10 cycles of sorption-desorption without any significant change in sorption capacity. A recovery of 100% was obtained for the metal ion with 0.5 M nitric acid as the eluent. Compared with nonimprinted polymer particles, the prepared Zn-imprinted sorbent showed high adsorption capacity, significant selectivity, and good site accessibility for Zn(II). Scatchard analysis revealed that the homogeneous binding sites were formed in the polymer. The equilibrium sorption data of Zn(II) by modified resin were analyzed by Langmuir, Freundlich, Temkin, and Redlich-Peterson models. Based on equilibrium adsorption data, the Langmuir, Freundlich, and Temkin constants were determined as 0.139, 12.82, and 2.34, respectively, at 25°C. PMID:25857899

  7. Determination of ibuprofen, naproxen and diclofenac in aqueous samples using a multi-template molecularly imprinted polymer as selective adsorbent for solid-phase extraction.

    PubMed

    Madikizela, Lawrence Mzukisi; Chimuka, Luke

    2016-09-01

    This study describes the application of multi-template molecularly imprinted polymer (MIP) as selective sorbent in the solid-phase extraction (SPE) of naproxen, ibuprofen and diclofenac from wastewater and river water. MIP was synthesized at 70°C by employing naproxen, ibuprofen and diclofenac as multi-templates, ethylene glycol dimethacrylate, 2-vinyl pyridine and toluene as cross-linker, functional monomer and porogen, respectively. Wastewater and river water samples (pH 2.5) were percolated through SPE cartridge packed with 50mg of the MIP. The cartridge was washed with 2mL of methanol-water 10:90% (v:v) prior to elution with 2mL of acetic acid-acetonitrile 20:80% (v:v). Quantification of eluted compounds was performed with high performance liquid chromatography equipped with photo diode array detection. The detection limits were 0.15, 1.00 and 0.63μgL(-1) for naproxen, ibuprofen and diclofenac, respectively. Recoveries for naproxen, ibuprofen and diclofenac in deionized water spiked at 5 and 50μgL(-1) were greater than 80%. Ibuprofen was the most frequently detected compound with maximum concentrations of 221, 67.9 and 11.4μgL(-1) in wastewater influent, effluent and river water, respectively. PMID:27268945

  8. Preparation of molecularly imprinted solid-phase microextraction fiber for the selective removal and extraction of the antiviral drug abacavir in environmental and biological matrices.

    PubMed

    Terzopoulou, Zoi; Papageorgiou, Myrsini; Kyzas, George Z; Bikiaris, Dimitrios N; Lambropoulou, Dimitra A

    2016-03-24

    In the present study, a molecularly imprinted solid-phase microextraction fiber (MIP-SPMEf) was synthesized and applied for the selective removal and extraction of the antiviral drug, abacavir (ABA). Morphology and structure characterization of fibers were performed by scanning electron microscopy and Fourier transform infrared spectra, respectively. The effects on the adsorption behavior of the process parameters were studied and the equilibrium data were fitted by the Langmuir, Freundlich and Langmuir-Freundlich models. The maximum adsorption capability (Qmax) was determined by Langmuir- Freundlich model and was 149 mg/g for MIP-SPMEf. In the next step, SPME methodology followed by liquid desorption and liquid chromatography with mass spectrometry (LC/MS) has been developed and evaluated for the determination of the target compound in environmental and biological matrices (surface waters, wastewaters and urine). Parameters that could influence SPME efficiency were investigated. Then, optimization of stirring speed, extraction time and salt content was carried out by using a central composite design (CCD) and response surface methodology (RSM). A quadratic model between dependent and independent variables was built. Under the optimum conditions (extraction time 40 min, stirring rate 650 rpm and salt content 0.3% NaCl w/v) the validated method presented a high sensitivity and selectivity with LODs and LOQs in the range of 10.1-13.6 and 33.3-43.9 ng/L, respectively. The developed method was successfully applied to the analysis of ABA in real samples. The percentage extraction efficiency ranged from 88 to 99% revealing good accuracy and absence of matrix effects. PMID:26944990

  9. Selective trace analysis of sulfonylurea herbicides in water and soil samples based on solid-phase extraction using a molecularly imprinted polymer.

    PubMed

    Zhu, Qing-Zhi; Degelmann, Petra; Niessner, Reinhard; Knopp, Dietmar

    2002-12-15

    A molecularly imprinted polymer (MIP) was synthesized using the herbicide metsulfuron-methyl (MSM) as a template, 2-(trifluoromethyl)acrylic acid as a functional monomer, divinylbenzene as a cross-linker, and dichloromethane as a porogen. This polymer was used as a solid-phase extraction material for the quantitative enrichment of five sulfonylureas (nicosulfuron, thifensulfuron-methyl, metsulfuron-methyl, sulfometuron-methyl, and chlorsulfuron) in natural water and soil samples and off-line coupled to a reversed-phase HPLC/diode array detection (HPLC/DAD). Washing solvent was optimized in terms of kind and volume for removing the matrix constituents nonspecifically adsorbed on the MIP. It has been shown that the nonspecific binding ability of the sulfonylureas to the polymer largely increased along with increasing the concentration of Ca2+ ions in the water sample, whereas complexation of divalent ions with EDTA eliminated this interference completely. The stability of MIP was tested by consecutive percolation of water sample, and it was shown that the performance of the MIP did not vary even after 200 enrichment and desorption cycles. Recoveries of the five sulfonylureas extracted from 1 L of tap water and surface water samples such as river water and rainwater at a 50 ng/L spike level were not lower than 96%. The recoveries of sulfonylureas extracted from 10-g soil sample at the 50 microg/kg level were in the range of 71-139%. Depending on the particular compound, the limit of detection varied from 2 to 14 ng/L in water and from 5 to 12 microg/kg in soil samples. The MIP was also compared with a commercially available C-18 column and an immunoaffinity support with encapsulated polyclonal anti-MSM antibodies in sol-gel glass. PMID:12521169

  10. A novel restricted access material combined to molecularly imprinted polymers for selective solid-phase extraction and high performance liquid chromatography determination of 2-methoxyestradiol in plasma samples.

    PubMed

    Du, Bin; Qu, Tiantian; Chen, Zheng; Cao, Xiaohui; Han, Shuping; Shen, Guopeng; Wang, Lei

    2014-11-01

    A feasibility study was performed in order to ensure the possibilities in using a restricted access material combined to molecularly imprinted polymers (RAM-MIP) as sorbent material in solid phase extraction (SPE) for clean-up of 2-methoxyestradiol (2-ME) from plasma samples. The MIP with hydrophilic external layer was designed by precipitation polymerization. The polymer was characterized by thermogravimetric analysis (TGA) and scanning electron microscope (SEM). The use of analogs of 2-ME as templates, in combination with a chromatographic separation of the analytes in the sample, overcame the problem of the template bleeding. To demonstrate the property of the RAM-MIP obtained, a comparison of commercially available C18 SPE was performed. The results showed that the RAM-MISPE recoveries were significantly higher than that of C18 SPE for 2-ME in trace concentration. During the extraction process, 2-ME was sufficiently cleaned for further chromatographic analysis with no interferences from template leakage and matrix. Good linearity was obtained from 0.06 to 20 μg mL(-1) with the correlation coefficient r>0.9991. The coefficient of variation of the inter-assay precision was less than 11.9%. The recoveries of 2-ME in rat plasma at three spiked levels were in the range of 99.10-101.00%. Based on the analytical validation results, the proposed method (RAM-MIP off-line SPE/HPLC) can be a useful tool to determine 2-ME in rat plasma samples. PMID:25127620

  11. Molecularly imprinted polymer as efficient sorbent of solid-phase extraction for determination of gonyautoxin 1,4 in seawater followed by high-performance liquid chromatography-fluorescence detection.

    PubMed

    Mei, Xiao-Qi; He, Xiu-Ping; Wang, Jiang-Tao

    2016-08-01

    A kind of new molecularly imprinted polymer (MIP) was synthesized by bulk polymerization using guanosine as dummy template molecule, α-methacrylic acid as functional monomer and ethylene glycol dimethyl acrylic ester as crosslinker. Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) showed that the MIP had homogenous and uniform-sized cavities. It was confirmed that the MIP had higher binding affinity and selectivity towards gonyautoxins 1,4 (GTX 1,4) than the non-imprinted polymer (NIP) according to the static equilibrium adsorption. An off-line molecularly imprinted solid-phase extraction (MISPE) method followed by high-performance liquid chromatography with fluorescence detection (HPLC-FLD) was established for the analysis of GTX 1,4. 0.1 mol/L acetic acid and 95:5 (v:v) methanol/water were optimized as the washing and elution solutions, respectively. The recoveries of spiked cultured seawater samples were satisfactory, as high as 88 %. Using this method, the concentrations of GTX 1,4 from cultured seawater samples of Alexandrium minutum and Alexandrium tamarense were detected to be 1.10 μg/L and 0.99 μg/L, respectively. Graphical Abstract The synthesis of molecularly imprinted polymer and molecularly imprinted solid-phase extraction analysis for gonyautoxin 1,4. PMID:27317255

  12. Determination of cocaine and its metabolites in plasma by porous membrane-protected molecularly imprinted polymer micro-solid-phase extraction and liquid chromatography-tandem mass spectrometry.

    PubMed

    Sánchez-González, Juan; García-Carballal, Sara; Cabarcos, Pamela; Tabernero, María Jesús; Bermejo-Barrera, Pilar; Moreda-Piñeiro, Antonio

    2016-06-17

    A selective molecularly imprinted polymer synthesized for the selective retention of cocaine (COC) and its metabolites [benzoylecgonine (BZE), ecgonine methyl ester (EME), and cocaethylene (CE)] was used as a solid adsorbent for assessing cocaine abuse by plasma analysis. The MIP beads (50mg) were loaded inside a cone shaped device made of a polypropylene (PP) membrane for micro-solid-phase extraction (μ-SPE). High performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was used for quantifying the analytes after MIP-μ-SPE. The best retention capabilities were reached when loading plasma samples (within the 0.1-5.0mL range), previously adjusted to pH 5.5 by orbital-horizontal shaking (150rpm, 50°C) for 10min. Analyte elution was achieved by subjecting the MIP-μ-SPE device to ultrasound (37kHz, 325W) with 10mL of dichloromethane/2-propanol/ammonium hydroxide (76:20:4) for 8min. After eluate evaporation to dryness and re-dissolution in 100μL of mobile phase, the MIP-μ-SPE method yielded a pre-concentration factor of 50. Precision was assessed by intra-day and inter-day assays, and accuracy (intraday and inter-day analytical recovery, as well as the analysis of a BTMF 1/11-B control serum sample) show that the developed method is highly precise and accurate. In addition, the limits of detection, ranging from 0.061ngmL(-1) for COC to 0.87ngmL(-1) for BZE, were low enough for confirmative conclusions regarding cocaine abuse. The method was used for screening/quantifying cocaine and metabolites in plasma samples from poly-drug abusers. PMID:27207577

  13. [Preparation of molecularly imprinted polymers using dummy template and the applications in selective solid-phase extraction of seven bisphenols from human urine, bovine serum and beer samples].

    PubMed

    Yang, Jiajia; Li, Yun; Wang Jinchengt; Sun, Xiaoli; Chen, Jiping

    2015-05-01

    A molecularly imprinted polymer (MIP) for selective recognition of seven bisphenols (BPs) was prepared using dummy template phenolphthalein (PP) by bulk polymerization. The characterization results of scanning electron microscopy and nitrogen adsorption-desorption measurements showed that the prepared PP-MIP possessed narrow particle diameter distribution (40-60 µm), a specific surface area (S(BET)) of 359.77 m2/g and a total pore volume (Vt) of 0.730 cm3/g. The adsorption capacity for bisphenol A (BPA) of PP-MIP was evaluated by static adsorption experiment. And the Scatchard analysis revealed that the maximum specific adsorption capacity of PP-MIP was 4.661 µmol/g. Good class selectivity for BPA and its six structural analogues of bisphenol B (BPB) , bisphenol E (BPE), bisphenol AF (BPAF), bisphenol S (BPS), bisphenol AP (BPAP) and bisphenol Z (BPZ) was demonstrated by the chromatographic evaluation experiment. The prepared PP-MIP was successfully used as solid-phase extraction (SPE) sorbent for the separation and purification of the seven BPs in human urine, bovine serum and beer samples. Meanwhile, an accurate and sensitive MIP-SPE-HPLC method was established for the determination of the seven BPs in human urine, bovine serum and beer samples. The limits of detection (LODs) for the three samples were in the range of 1.2-2.0 µg/L. The results showed that good linearities were obtained in the range of 0.02-2 mg/L for the seven BPs and the correlation coefficients (r) were higher than 0.999 8. The recoveries of the BPs spiked in blank samples at two spiked levels (100 and 500 µg/L for each BP) were in the range of 90.1%-107.1% with the RSDs ≤ 8.1%. The proposed method is simple and reliable for the rapid detection of the seven BPs in human urine, bovine serum and beer samples. PMID:26387203

  14. Development of magnetic molecularly imprinted polymers for solid phase extraction of cocaine and metabolites in urine before high performance liquid chromatography - tandem mass spectrometry.

    PubMed

    Sánchez-González, Juan; Jesús Tabernero, María; Bermejo, Ana María; Bermejo-Barrera, Pilar; Moreda-Piñeiro, Antonio

    2016-01-15

    A magnetic molecularly imprinted polymer (MMIP) has been synthesized and applied for cocaine (COC) and metabolites (benzoylecgonine, BZE; cocaethylene, CE; and ecgonine methyl ester, EME) recognition/pre-concentration in urine samples. The MMIP has been prepared using COC as a template molecule, ethylene dimethacrylate (EDMA) as a functional monomer, divinylbenzene (DVB) as a cross-linker, Fe3O4 magnetite as a magnetic component, and 2,2'-azobisisobutyronitrile (AIBN) as an initiator. The best results (MIP layer on the surface of the magnetic nanoparticles) and physical properties of the prepared MMIP were obtained when assisting the synthesis procedure with ultrasounds (325W, 37kHz, 30°C, 4h). After solid phase extraction (SPE) with the prepared adsorbent material, analytes were determined by high performance liquid chromatography - tandem mass spectrometry (HPLC-MS/MS). Variables affecting the SPE process (batch mode) were fully evaluated. Optimum retention of analytes (1.8mL of urine and 50mg of MMIP) was achieved by fixing the urine pH at 5.5 (use of a KH2PO4/NaOH, pH 5.5 buffer solution), and magnetic stirring (25°C, 700rpm) for 10min. Elution was performed by using 2mL of a dichloromethane/2-propanol/ammonium hydroxide (75:20:5) mixture under ultrasounds (325W, 35kHz, room temperature) for 5min. The method was validated according to the guidance for bioanalytical method validation of the US Department of Health and Human Services, Food and Drug Administration. The detection limits were in the range of 0.39-1.4ngL(-1). The relative standard deviations of intra- and inter-day tests ranged from 5 to 11% and from 3 to 11%, respectively. Analytical recoveries were in the range of 79-106% when spiking drug-free urine samples at three concentration levels. Good results were also obtained after analyzing an FDT +25% control material. The applicability of the method was proved for screening/quantifying COC, BZE, CE and EME in several samples from poly-drug abusers

  15. Computational design and fabrication of core-shell magnetic molecularly imprinted polymer for dispersive micro-solid-phase extraction coupled with high-performance liquid chromatography for the determination of rhodamine 6G.

    PubMed

    Xie, Jin; Xie, Jie; Deng, Jian; Fang, Xiangfang; Zhao, Haiqing; Qian, Duo; Wang, Hongjuan

    2016-06-01

    A novel core-shell magnetic nano-adsorbent with surface molecularly imprinted polymer coating was fabricated and then applied to dispersive micro-solid-phase extraction followed by determination of rhodamine 6G using high-performance liquid chromatography. The molecularly imprinted polymer coating was prepared by copolymerization of dopamine and m-aminophenylboronic acid (functional monomers), in the presence of rhodamine 6G (template). The selection of the suitable functional monomers was based on the interaction between different monomers and the template using the density functional theory. The ratios of the monomers to template were further optimized by an OA9 (3(4) ) orthogonal array design. The binding performances of the adsorbent were evaluated by static, kinetic, and selective adsorption experiments. The results reveal that the adsorbent possesses remarkable affinity and binding specificity for rhodamine 6G because of the enhanced Lewis acid-base interaction between the B(Ш) embedded in the imprinted cavities and the template. The nano-adsorbent was successfully applied to dispersive micro-solid-phase extraction coupled to high-performance liquid chromatography for the trace determination of rhodamine 6G in samples with a detection limit of 2.7 nmol/L. Spiked recoveries ranged from 93.0-99.1, 89.5-92.7, and 86.9-105% in river water, matrimony vine and paprika samples, respectively, with relative standard deviations of less than 4.3%. PMID:27120290

  16. Electrochemically grown imprinted polybenzidine nanofilm on multiwalled carbon nanotubes anchored pencil graphite fibers for enantioselective micro-solid phase extraction coupled with ultratrace sensing of d- and l-methionine.

    PubMed

    Prasad, Bhim Bali; Srivastava, Amrita; Pandey, Indu; Tiwari, Mahavir Prasad

    2013-01-01

    An alternative method is presented for the modification of pencil graphite fibers using surface imprinting technology. In this new approach, we have adopted surface initiated electropolymerization of benzidine monomer, with simultaneous imprinting of template (d- and l-methionine), on carboxylated multiwalled carbon nanotubes anchored pencil graphite fiber. This yielded a nanostructured ultrathin imprinted film (58.3nm) uniformly coated all along the perimeter and length of pencil graphite fiber, for micro-solid phase extraction with substantial adsorption capability. The same film is coated over the exposed tip of the pencil graphite fiber to serve as a complementary molecularly imprinted polymer-sensor. Both extraction and sensing devices are not capable to measure the stringent limit (0.016ngmL(-1)) of clinical detection of methylenetetrahydrofolate reductase (MTHFR) gene mutation caused by acute methionine depletion, when used alone. However, on combination of both techniques, a successful enantioselective analysis of d- and l-methionine with excellent analytical figures of merit [limit of quantitation range: 0.03-30.00ngmL(-1), limit of detection: 0.0098ngmL(-1) (RSD=2.04, S/N=3)] could be achieved without any problem of non-specific false-positive contribution and cross-reactivity, in real samples. PMID:23262195

  17. Water-compatible magnetic imprinted nanoparticles served as solid-phase extraction sorbents for selective determination of trace 17beta-estradiol in environmental water samples by liquid chromatography.

    PubMed

    Hao, Yi; Gao, Ruixia; Shi, Lu; Liu, Dechun; Tang, Yuhai; Guo, Zengjun

    2015-05-29

    Endocrine disrupting compounds (EDCs) are a potential risk for wildlife and humans for their existence in water. The efficient extraction and clean-up steps are required before detection of low concentration levels of EDCs. In this work, a novel water-compatible magnetic molecularly imprinted nanoparticles is synthesized for the selective extraction of 17β-estradiol (E2) in environmental water samples. The preparation is carried out by introducing aldehyde groups to the surface of amino-functionalized magnetic nanoparticles through a simple one-step modification, followed by copolymerization of functional monomer gelatin and template E2 via surface imprinting technique. The gelatin with abundant active groups could not only act as functional monomer reacting with template, but also assemble covalently at the surface of magnetic nanoparticles. At the same time, gelatin would improve the water-compatibility of imprinted materials for attaining high extraction efficiency. To obtain high imprinting effect, the preparation conditions are optimized in detail using Central composite design-response surface methodology. The resultant polymers have uniform spherical shape with a shell thickness of about 8nm, stable crystalline form, and super-paramagnetic property. Meanwhile, the obtained polymers have high capacity of 12.87mgg(-1) and satisfactory selectivity to template molecule. To testify the feasibility of the magnetic imprinted polymers in sample pretreatment, a method for determination of trace E2 in environmental water samples was set up by combination of solid-phase extraction (SPE) using the prepared polymers as sorbents and HPLC for rapid isolation and determination of E2. The limit of detection of proposed method is 0.04ngmL(-1), the intra- and inter-day relative standard deviations (RSDs) are less than 4.6% and 5.7%, respectively. The recoveries of E2 from environmental water samples are in the range from 88.3% to 99.1% with the RSDs less than 7.2%. PMID

  18. Highly selective dummy molecularly imprinted polymer as a solid-phase extraction sorbent for five bisphenols in tap and river water.

    PubMed

    Sun, Xiaoli; Wang, Jincheng; Li, Yun; Jin, Jing; Zhang, Baoqin; Shah, Syed Mazhar; Wang, Xueli; Chen, Jiping

    2014-05-23

    A simple and fast method for both dummy template selection and polymer composition optimization is proposed here. A series of dummy templates for bisphenols imprinting were screened by running them on a non-imprinted polymer (NIP) column with porogen solvent as mobile phase. The tested dummy templates mainly involved bisphenol S (BPS), bromobisphenol A (TBBPA), bisphenol F (BPF), bisphenol E (BPE), bisphenol B (BPB), bisphenol AF (BPAF), 2,2',6,6'-tetramethyl-4,4'-sulfonyldiphenol (BS-TM) and 4,4'-diaminodiphenylmethane (DADPM). Different monomers and porogens were also investigated for BPS and DADPM using the same method. BPS dummy template was finally selected with acetonitrile and 4-VP as porogen and monomer. The resulting dummy molecularly imprinted polymer (DMIP) achieved superior affinities for BPF, BPE, BPA, BPB and BPAF with imprinting factors 14.5, 13.8, 8.7, 5.7 and 4.2, respectively. An efficient method based on BPS-DMIP-SPE coupled with HPLC-UV was developed for selective extraction of BPF, BPE, BPA, BPB and BPAF in water samples. The method showed excellent recoveries (89.4-102.0%) and precision (RSD 0.3-4.8%, n=5) for tap and river water samples spiked at three concentration levels each (40, 200 and 1000ngL(-1)). The detection limits ranged between 2.2 and 3.8ngL(-1) with a sample volume of 500mL. The result demonstrated the superiority of the optimized method for selective extraction of BPs in water samples at the ngL(-1) level. PMID:24726373

  19. On-Line Restricted Access Molecularly Imprinted Solid-Phase Extraction of Selective Serotonin Reuptake Inhibitors Directly from Untreated Human Plasma Samples Followed by HPLC-UV Analysis.

    PubMed

    da Silva, Katrine Kyona Muniz Sirgom; Boralli, Vanessa Bergamin; Wisniewski, Célio; Figueiredo, Eduardo Costa

    2016-03-01

    In this article, we proposed a new restricted access molecularly imprinted polymer coated with bovine serum albumin (RAMIP-BSA) to be used in a multidimensional chromatographic system applied for the analysis of six selective serotonin reuptake inhibitors (SSRIs) directly from untreated human plasma samples. Fluoxetine, methacrylic acid and ethylene glycol dimethacrylate were used as the template, functional monomer and cross-linker, respectively. The imprinted polymer was covered with a bovine serum albumin (BSA) layer via the interconnections between the amine groups of the BSA using glutaraldehyde as a cross-linker. The obtained RAMIP-BSA was able to extract the SSRIs directly from the human plasma, while ∼100% of the proteins were excluded from the sample. Selectivity coefficients were calculated for fluoxetine (template) in comparison with venlafaxine, duloxetine, citalopram, fluvoxamine, paroxetine and sertraline, and the values were >1 in all cases, attesting to the presence of binding sites in the imprinted polymer. The method presented analytical ranges from 20 to 500 µg/L and correlation coefficients >0.99 for all of the SSRIs (fluoxetine, venlafaxine, duloxetine, citalopram, fluvoxamine and sertraline). Precision and accuracy presented variation coefficients and relative errors <14.5% and within the range of -19.18 to 3.8%, respectively. In all cases, the apparent recoveries were >85%. The proposed method was able to analyze three samples per hour, and each column was used at least 50 times without any significant changes in its performance. PMID:26487639

  20. Preparation of new solid phase micro extraction fiber on the basis of atrazine-molecular imprinted polymer: application for GC and GC/MS screening of triazine herbicides in water, rice and onion.

    PubMed

    Djozan, Djavanshir; Ebrahimi, Bahram

    2008-06-01

    A simple polymerization strategy has been used to produce a monolithic solid phase micro extraction (SPME) fiber on the basis of molecularly imprinted polymer able to couple with GC and GC-MS for selective extraction and analysis of triazine herbicides. A fiber was produced by copolymerization of methacrylic acid-ethylene glycol dimethacrylate imprinted with atrazine. The effective factors influencing the polymerization have been investigated and are detailed here. At the optimum conditions the prepared fiber is firm, inexpensive, durable and thermally stable up to 280 degrees C which has vital importance in SPME coupled with GC or GC/MS. In addition, the influences of pH, extraction time and temperature on the extraction efficiency of analytes were optimized. Selectivity of prepared fibers in relation to triazine herbicides and some of the other pesticide has been investigated. The high extraction efficiency was obtained for atrazine, simazine, propazine, cyanazine, ametryn, terbutryn and prometryn yielding the detection limits of 20, 70, 80, 81, 69, 88 and 68 ng mL(-1), respectively and the high quantities of recoveries. The reliability of prepared fiber to extraction of atrazine and other analogues in real samples has been investigated and proved by implementation of SPME in spiked samples such as tap water, onion and rice. PMID:18482598

  1. Evaluation of two molecularly imprinted polymers for the solid-phase extraction of natural, synthetic and mycoestrogens from environmental water samples before liquid chromatography with mass spectrometry.

    PubMed

    González-Sálamo, Javier; Socas-Rodríguez, Bárbara; Hernández-Borges, Javier; Del Mar Afonso, María; Rodríguez-Delgado, Miguel Ángel

    2015-08-01

    In this work, we have compared the selectivity of two commercial molecularly imprinted polymers (AFFINIMIP®SPE Estrogens and AFFINIMIP®SPE Zearalenone) for the extraction of 12 estrogenic compounds of interest (i.e. 17α-estradiol, 17β-estradiol, estrone, hexestrol, 17α-ethynylestradiol, diethylstibestrol, dienestrol, zearalenone, α-zearalanol, β-zearalanol, α-zearalenol and β-zearalenol) from different water samples. High-performance liquid chromatography coupled with ion trap mass spectrometry with electrospray ionization was used for their determination. Results showed that although both molecularly imprinted polymeric cartridges were specifically designed for different groups of analytes (natural estrogens like estradiol in the first case and zearalenone derivatives in the second) they nearly have the same extraction performance (with recovery values in the range 65-101%) for the same analytes in Milli-Q water because of the cross-reactivity of the polymer. However, when more complex water samples were analyzed, it was clear that the behavior was different and that the AFFINIMIP®SPE Estrogens showed less cross-reactivity than the other cartridge. Validation of the proposed methodology with both cartridges revealed that the extraction was reproducible and that the final limits of detection of the proposed method were in the low ng/L range. PMID:26012850

  2. Multiplexed Colorimetric Solid-Phase Extraction

    NASA Technical Reports Server (NTRS)

    Gazda, Daniel B.; Fritz, James S.; Porter, Marc D.

    2009-01-01

    Multiplexed colorimetric solid-phase extraction (MC-SPE) is an extension of colorimetric solid-phase extraction (C-SPE) an analytical platform that combines colorimetric reagents, solid phase extraction, and diffuse reflectance spectroscopy to quantify trace analytes in water. In CSPE, analytes are extracted and complexed on the surface of an extraction membrane impregnated with a colorimetric reagent. The analytes are then quantified directly on the membrane surface using a handheld diffuse reflectance spectrophotometer. Importantly, the use of solid-phase extraction membranes as the matrix for impregnation of the colorimetric reagents creates a concentration factor that enables the detection of low concentrations of analytes in small sample volumes. In extending C-SPE to a multiplexed format, a filter holder that incorporates discrete analysis channels and a jig that facilitates the concurrent operation of multiple sample syringes have been designed, enabling the simultaneous determination of multiple analytes. Separate, single analyte membranes, placed in a readout cartridge create unique, analyte-specific addresses at the exit of each channel. Following sample exposure, the diffuse reflectance spectrum of each address is collected serially and the Kubelka-Munk function is used to quantify each water quality parameter via calibration curves. In a demonstration, MC-SPE was used to measure the pH of a sample and quantitate Ag(I) and Ni(II).

  3. Molecularly imprinted calixarene fiber for solid-phase microextraction of four organophosphorous pesticides in fruits.

    PubMed

    Li, Jing-Wen; Wang, Yu-Long; Yan, Shan; Li, Xiu-Juan; Pan, Si-Yi

    2016-02-01

    Calixarene was used as a functional monomer to fabricate a molecularly imprinted polymer (MIP) by sol-gel technique for solid-phase microextraction (SPME) of parathion-methyl and its structural analogs. The MIP-coated fiber possessed excellent thermal and chemical stability as well as high extraction capacity. Its selectivity and possible recognition mechanism were investigated. The similarities in molecular shape and functional group play a key role in the selective recognition of the imprinted material. Any changes to the structure of the template would decrease the imprinting factor. A comparison of MIP-SPME was made with liquid-liquid extraction coupled with gas chromatography for the determination of organophosphorus pesticides (OPPs) in fruits. Much lower limits of detection and better recoveries were achieved by SPME in spiked apple and pineapple samples. The experiment demonstrates that the proposed method using the calixarene MIP fiber was more suitable for selective determination of trace OPPs in those fruit samples. PMID:26304345

  4. DNA Extraction: Organic and Solid-Phase.

    PubMed

    Altayari, Wafa

    2016-01-01

    DNA extraction remains a critical step in DNA profiling of biological material recovered from scenes of crime. In the forensic community several methods have gained popularity, including Chelex(®), organic extraction, and solid-phase extraction. While some laboratories streamlined their processes and only use one method we have retained several methods and continue to use these for different sample types. In this chapter we present three methods that have been used for several years in our laboratory. PMID:27259731

  5. Dual-layer solid-phase extraction based on molecular imprinting technology: Seeking a route to enhance selectivity for trace analysis of pesticide residues in olive oil.

    PubMed

    Garcia, Raquel; Carreiro, Elisabete P; Nunes, José; da Silva, Marco Gomes; Freitas, Ana Maria Costa; Burke, Anthony J; Cabrita, Maria João

    2016-07-01

    Aiming to introduce a multiresidue analysis for the trace detection of pesticide residues belonging to organophosphorus and triazine classes from olive oil samples, a new sample preparation methodology comprising the use of a dual layer of "tailor-made" molecularly imprinted polymers (MIPs) SPE for the simultaneous extraction of both pesticides in a single procedure has been attempted. This work has focused on the implementation of a dual MIP-layer SPE procedure (DL-MISPE) encompassing the use of two MIP layers as specific sorbents. In order to achieve higher recovery rates, the amount of MIP layers has been optimized as well as the influence of MIP packaging order. The optimized DL-MISPE approach has been used in the preconcentration of spiked organic olive oil samples with concentrations of dimethoate and terbuthylazine similar to the maximum residue limits and further quantification by HPLC. High recovery rates for dimethoate (95%) and terbuthylazine (94%) have been achieved with good accuracy and precision. Overall, this work constitutes the first attempt on the development of a dual pesticide residue methodology for the trace analysis of pesticide residues based on molecular imprinting technology. Thus, DL-MISPE constitutes a reliable, robust, and sensitive sample preparation methodology that enables preconcentration of the target pesticides in complex olive oil samples, even at levels similar to the maximum residue limits enforced by the legislation. PMID:27062483

  6. On-line restricted access molecularly imprinted solid phase extraction of ivermectin in meat samples followed by HPLC-UV analysis.

    PubMed

    de Lima, Marcela Marília; Vieira, André Coutinho; Martins, Isarita; Boralli, Vanessa Bergamin; Borges, Keyller Bastos; Figueiredo, Eduardo Costa

    2016-04-15

    A new restricted access molecularly imprinted polymer coated with bovine serum albumin (RAMIP-BSA) was synthesized, characterized and used for direct analysis of ivermectin from bovine meat samples, in a two-dimensional liquid chromatography system with UV detection. Ivermectin, 4-vynilpiridine and ethylene glycol dimethacrylate were employed as template, functional monomer and cross-linker, respectively. A BSA layer was cross-linked around the polymer, resulting in a biocompatible chemical barrier able to eliminate about 100% of protein from the samples. Ivermectin was extracted from the minced meat samples through a solvent extraction using methanol:water (70:30, v:v), and the extracts were directly injected into the two-dimensional liquid chromatography system, without any other treatment. Samples, fortified with ivermectin from 50 to 500 μg kg(-1), were used to build the analytical calibration curve (r=0.996). The limit of quantification was 50 μg kg(-1). Precision and accuracy presented variation coefficients, as well as relative errors lower than 17.0% and within -18.5% and 22.0%, respectively. PMID:26616918

  7. Studies of ion-imprinted polymers for solid-phase extraction of ruthenium from environmental samples before its determination by electrothermal atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Zambrzycka, Elżbieta; Roszko, Dorota; Leśniewska, Barbara; Wilczewska, Agnieszka Z.; Godlewska-Żyłkiewicz, Beata

    2011-07-01

    The examination of the effect of interfering ions on the analytical signal of ruthenium measured by electrothermal atomic absorption spectrometry was initially performed in this work. The complexes of ruthenium(III) with thiosemicarbazide (TSd) and acetaldehyde thiosemicarbazone (AcTSn) were prepared and imprinted in polymeric network. The ion-imprinted polymers were synthesized by copolymerization of methacrylic acid, as functional monomer and ethylene glycol dimethacrylate, as crosslinking agent in the presence of 2,2-azobisisobutyronitrile as initiator. The effects of sample volume, pH, and flow rate on the extraction of analyte were studied in dynamic mode. The optimum pH for quantitative retention of ruthenium on each of the studied sorbents was 7.5 ± 0.5. The elution of analyte was completed with 0.2 mol L -1 thiourea in 0.2 mol L -1 HCl. The effect of matrix ions on ruthenium(III) separation process was studied. The analytical performance of the Ru-TSd polymer in the presence of competing ions was better than Ru-AcTSn polymer, considering recovery of analyte, reproducibility of results, selectivity coefficients, and sorbent capacity. The detection limit of the proposed method (0.16 ng mL -1 on Ru-TSd and 0.25 ng mL -1 on Ru-AcTSn) is lower in comparison with the previously published methods. The developed separation method was successfully applied to the determination of trace amounts of ruthenium in spiked water samples, sludge, grass, and human hair.

  8. Polypyrrole hollow fiber for solid phase extraction.

    PubMed

    Tian, Tian; Deng, Jianjun; Xie, Zhuoying; Zhao, Yuanjin; Feng, Zhangqi; Kang, Xuejun; Gu, Zhongze

    2012-04-21

    We have developed a solid-phase extraction method based on conductive polypyrrole (PPy) hollow fibers which were fabricated by electrospinning and in situ polymerization. The electrospun poly (e-caprolactone) (PCL) fibers were employed as templates for the in situ surface polymerization of PPy under mechanical stirring or ultrasonication to obtain burr-shaped or smooth fiber shells, respectively. Hollow PPy fibers, achieved by removing the PCL templates, were the ideal sorbents for solid phase extraction of polar compounds due to their inherent multi-functionalities. By using the hollow PPy fibers, two important neuroendocrine markers of behavioural disorders, 5-hydroxyindole-3-acetic acid and homovanillic acid, were successfully extracted. Under the optimized conditions, the absolute recoveries of the above two neuroendocrine markers were 90.7% and 92.4%, respectively, in human plasma. Due to its simplicity, selectivity and sensitivity, the method may be applied to quantitatively analyse the concentrations of polar species in complex matrix samples. PMID:22398754

  9. Behavior of Phenols and Phenoxyacids on a Bisphenol-A Imprinted Polymer. Application for Selective Solid-Phase Extraction from Water and Urine Samples

    PubMed Central

    Herrero-Hernández, Eliseo; Carabias-Martínez, Rita; Rodríguez-Gonzalo, Encarnacion

    2011-01-01

    A molecularly imprinted polymer (MIP), obtained by precipitation polymerisation with 4-vinylpyridine as the functional monomer, ethylene glycol dimethacrylate as cross-linker, and bisphenol-A (BPA) as template, was prepared. The binding site configuration of the BPA-MIP was examined using Scatchard analysis. Moreover, the behaviour of the BPA-MIP for the extraction of several phenolic compounds (bisphenol-A, bisphenol-F, 4-nitrophenol, 3-methyl-4-nitrophenol) and phenoxyacid herbicides such as 2,4-D, 2,4,5-T and 2,4,5-TP has been studied in organic and aqueous media in the presence of other pesticides in common use. It was possible to carry out the selective preconcentration of the target analytes from the organic medium with recoveries of higher than 70%. In an aqueous medium, hydrophobic interactions were found to exert a remarkably non-specific contribution to the overall binding process. Several parameters affecting the extraction efficiency of the BPA-MIP were evaluated to achieve the selective preconcentration of phenols and phenoxyacids from aqueous samples. The possibility of using the BPA-MIP as a selective sorbent to preconcentrate these compounds from other samples such as urine and river water was also explored. PMID:21686187

  10. Synthesis of mimic molecularly imprinted ordered mesoporous silica adsorbent by thermally reversible semicovalent approach for pipette-tip solid-phase extraction-liquid chromatography fluorescence determination of estradiol in milk.

    PubMed

    Wang, Lu; Yan, Hongyuan; Yang, Chunliu; Li, Zan; Qiao, Fengxia

    2016-07-22

    A mimic molecularly imprinted ordered mesoporous silica (MIOMS) adsorbent was prepared utilizing a thermally reversible semicovalent approach. The thermally reversible covalent template-monomer complex was firstly synthesized by employing 4,4'-sulfonyldiphenol (BPS) and (3-isocyanatopropyl) triethoxysilane (ICPTES) as template and monomer, respectively. The template-monomer complex was incorporated into ordered mesoporous silica via a simple self-assembly process. The adsorption experiment illustrated that the imprint-removed silica (MIOMS-ir) had higher special recognition ability (250μgg(-1)) for estradiol (E2) than the non-imprinted silica (NIOMS-ir) (25μgg(-1)). MIOMS-ir was applied as an adsorbent in pipette-tip solid-phase extraction (PT-SPE) coupled with liquid chromatography-fluorescence detector (LC-FLD) for determination of E2 in milk samples. Under the optimized conditions, only 3mg of the adsorbent, 0.3mL of water as washing solvent, and 0.5mL of acetonitrile-acetic acid (96:4, v/v) as elution solvent were used in the pretreatment procedure of milk samples. Good calibration linearity was obtained in a range of 25ngL(-1) to 1000ngL(-1), and the recoveries at three spiked levels were ranged from 95.4% to 107.0% with relative standard deviations (RSDs) ≤3.1% (n=3). The proposed MIOMS-ir-PT-SPE-LC-FLD method combined the advantages of PT-SPE and ordered mesoporous material such as ease assembly, low cost, high extraction efficiency and large specific surface area, so it is a potential pretreatment strategy for the extraction and determination of E2 in complex milk samples. PMID:27328886

  11. Selective solid-phase extraction using molecularly imprinted polymers for analysis of venlafaxine, O-desmethylvenlafaxine, and N-desmethylvenlafaxine in plasma samples by liquid chromatography-tandem mass spectrometry.

    PubMed

    Miranda, Luis Felippe C; Domingues, Diego S; Queiroz, Maria Eugênia C

    2016-08-01

    This paper focuses on the development of a novel miniaturized molecularly imprinted solid-phase extraction (MISPE) and ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method to determine venlafaxine (VEN), O-desmethylvenlafaxine (ODV), and N-desmethylvenlafaxine (NDV) in plasma samples. The molecularly imprinted polymer (MIP) was prepared by the precipitation polymerization approach; VEN, metacrylic acid, ethylene glycol dimethacrylate, 2,2-azobisisobutyronitrile, and toluene were used as template, monomer, crosslinker, initiator, and porogen solvent, respectively. MIP and of the non-imprinted control polymer (NIP) sorbents were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. MIP phase presented higher extraction efficiency (MISPE, using plasma samples spiked with VEN) than the NIP phase (84 and 49% recovery rates, respectively). Analysis of other antidepressants with different chemical structures by MISPE-UHPLC-MS/MS attested to the selectivity of the developed MIP. The developed method presented precision assays with coefficients of variation (CV) smaller than 15%; accuracy assays with relative standard error (RSE%) values ranging from -12 to 16%, and linear ranges from 3 to 700ngmL(-1) for VEN, from 5 to 700ngmL(-1) for ODV, and from 3 to 500ngmL(-1) for NDV. The coefficients of determination (r(2)) were higher than 0.995. The lack-of-fit test also attested to the linearity of this method. This method was successfully applied to determine VEN, NDV, and ODV in plasma samples from depressed patients undergoing therapy with VEN. PMID:27388659

  12. Core-shell SiO2 -coated Fe3 O4 with a surface molecularly imprinted polymer coating of folic acid and its applicable magnetic solid-phase extraction prior to determination of folates in tomatoes.

    PubMed

    Areerob, Yonrapach; Sricharoen, Phitchan; Limchoowong, Nunticha; Chanthai, Saksit

    2016-08-01

    A novel core-shell magnetic surface molecularly imprinted polymer with folic acid as a template was successfully synthesized by the sol-gel method. To generate Lewis acid sites in the silica matrix for the interaction of the metal coordinate with the template, 3-aminopropyltriethoxysilane was used as a functional monomer, tetraethyl orthosilicate as a cross-linker, and aluminum ions as a dopant. The magnetite encapsulated by the silica shell plays an important role as a magnetic-coated polymer. The synthesized product was characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and FTIR and UV/Vis spectroscopy. The powder X-ray diffraction patterns, FTIR and UV/Vis spectra confirmed the characteristics of the as-prepared silica coated magnetite and folic acid molecularly imprinted polymer. It was successfully applied for magnetic solid-phase extraction prior to the determination of folates in tomato samples using high-performance liquid chromatography with photodiode array detection. The detection limit of the proposed method was 1.67 μg/L, and results were satisfactory, with a relative standard deviation of < 3.94%. PMID:27296679

  13. Ultrasonic-assisted magnetic solid phase extraction of morphine in urine samples by new imprinted polymer-supported on MWCNT-Fe3O4-NPs: Central composite design optimization.

    PubMed

    Kolaei, Milad; Dashtian, Kheibar; Rafiee, Zahra; Ghaedi, Mehrorang

    2016-11-01

    Multiwalled carbon nanotubes (MWCNTs) were magnetized with Fe3O4 nanoparticles (MWCNTs-Fe3O4-NPs) and subsequently coated by vinyl end groups (Vinyltrimethoxysilane). MWCNT-Fe3O4-NPs were used as support for a new morphine (MO) molecularly imprinted polymer (MWCNT-Fe3O4-NPs@MO-MIP) by surface imprinting polymerization method. The MWCNT-Fe3O4-NPs@MO-MIP was characterized by FTIR, VSM and SEM techniques and successfully used for determination of MO. Ultrasonic-assisted magnetic solid phase extraction followed by UV-vis spectrophotometer (UAMSPE-UV-vis) was investigated for MWCNT-Fe3O4-NPs@MO-MIP and compared with non-imprinted polymer (NIP) using batch method. Central composite design under response surface methodology was used for the evaluation of the effect of variables, individually, as well as their possible interaction effects on the adsorption process. The variables such as sonication time, MWCNT-Fe3O4-NPs@MO-MIP mass, initial concentration of MO and pH were investigated in this study. At optimum experimental conditions, UAMSPE-UV-vis method was exhibited a linear range of 0.8-8.7mgL(-1) of the MO concentration with a detection limit of 0.18mgL(-1). The relative standard deviation for the analyte was found to be lower than 2.32%. The MWCNT-Fe3O4-NPs@MO-MIP adsorption capacity was found to be 37.01mgg(-1). The enrichment and preconcentration factors were found to be 107.01 and 98.21, respectively. The developed method was finally applied successfully to the determination of MO in urine and wastewater samples with the recoveries ranged from 96.40 to 105.6%. PMID:27245975

  14. Preparation and binding study of solid-phase microextraction fiber on the basis of ametryn-imprinted polymer: application to the selective extraction of persistent triazine herbicides in tap water, rice, maize and onion.

    PubMed

    Djozan, Djavanshir; Mahkam, Mehrdad; Ebrahimi, Bahram

    2009-03-20

    A monolithic ametryn molecular-imprinted polymer based on a simple polymerization method was fabricated for use as new solid-phase microextraction (SPME) fiber, which can be coupled with GC and GC/MS for selective extraction and analysis of triazine herbicides. Methacrylic acid (MAA), ethylene glycol dimethacrylate (EDMA) and ametryn bear role of functional monomer, cross-linker and template, respectively. In the optimized conditions the fabricated fiber showed better molecular recognition abilities for methylthiotriazine herbicides than chloro-triazine herbicides. By use of bi-Langmuir isotherm model the evaluated equilibrium constants for ametryn were 0.01 and 890.69 microM(-1), and the numbers of binding sites were 129.98 and 5.82 nmol g(-1), respectively. The high extraction efficiency was obtained for ametryn, prometryn, terbutryn, atrazine, simazine, propazine, and cyanazine, yielding the detection limits of 14, 28, 45, 56, 85, 95 and 74 ng mL(-1), respectively by GC with flame ionization detection. The reliability of the prepared fiber for extraction of ametryn and other analogues in real samples has been investigated and proved by using spiked samples such as tap water, rice, maize, and onion. PMID:19185305

  15. Synthesis, recognition characteristics and properties of l-3-n-butylphthalide molecularly imprinted polymers as sorbent for solid-phase extraction through precipitation polymerization.

    PubMed

    Zhang, Wen; Tan, Ni; Jia, Xiaohe; Wang, Guoping; Long, Wei; Li, Xiaolong; Liao, Sen; Hou, Dan

    2015-08-01

    L-3-n-butylphthalide molecularly imprinted polymers (MIPs) were synthesized using l-3-n-butylphthalide as template molecule, acrylamide as functional monomer, ethylene glycol dimethacrylate as cross-linking agent, and acetone as the porogenic solvent through precipitation polymerization. The non-imprinted polymers (NIPs) were prepared with the same procedure, but with the absence of template molecule. The optimum preparation conditions of the MIPs such as the functional monomer, the porogenic solvent, the molar ratio of the template to the functional monomer and the molar ratio of the template to the cross-linker were investigated in detail. Prior to the polymerization, the molecular simulation with the computer-aided design was used to help choose a suitable polymerization porogen for the molecularly imprinted pre-assembled system and study the interactions between l-NBP and the functional monomers. The synthesized polymers were characterized with FTIR and SEM to observe their structures as well as the morphologies, and their adsorption properties were respectively evaluated by static and dynamic adsorption as well as selectivity experiments. Scatchard analyses revealed that there were high and low affinity sites formed in the MIPs, which elucidated good affinity to l-NBP in the ethanol system. The adsorption capacity of the MIPs for l-NBP was 3.561 mg g(-1), with an imprinting factor (α) of 2.321 when compared with that of the NIPs. Scatchard analysis illustrated that the binding sites with affinity for l-3-n-butylphthalide molecules were formed in the prepared MIPs. PMID:26042704

  16. Selective solid phase extraction of copper using a new Cu(II)-imprinted polymer and determination by inductively coupled plasma optical emission spectroscopy (ICP-OES)

    PubMed Central

    Yilmaz, Vedat; Arslan, Zikri; Hazer, Orhan; Yilmaz, Hayriye

    2014-01-01

    This work reports the preparation of a novel Cu(II)-ion imprinted polymer using 2-thiozylmethacrylamide (TMA) for on-line preconcentration of Cu(II) prior to its determination by inductively coupled optical emission spectroscopy (ICP-OES). Cu(II)-TMA monomer (complex) was synthesized and copolymerized via bulk polymerization method in the presence of ethyleneglycoldimethacrylate cross-linker. The resulting polymer was washed with 5% (v/v) HNO3 to remove Cu(II) ions and then with water until a neutral pH. The ion imprinted polymer was characterized by FT-IR and scanning electron microscopy. The experimental conditions were optimized for on-line preconcentration of Cu(II) using a minicolumn of ion imprinted polymer (IIP). Quantitative retention was achieved between pH 5.0 and 6.0, whereas the recoveries for the non-imprinted polymer (NIP) were about 61%. The IIP showed about 30 times higher selectivity to Cu(II) in comparison to NIP. The IIP also exhibited excellent selectivity for Cu(II) against the competing transition and heavy metal ions, including Cd, Co, Cr, Fe, Mn, Ni, Pb and Zn. Computational calculations revealed that the selectivity of IIP was mediated by the stability of Cu(II)-TMA complex which was far more stable than those of Co(II), Ni(II) and Zn(II) that have similar charge and ionic radii to Cu(II). A volume of 10 mL sample solution was loaded onto the column at 4.0 mL min−1 by using a sequential injection system (FIALab 3200) followed by elution with 1.0 mL of 2% (v/v) HNO3. The relative standard deviation (RSD) and limit of detection (LOD, 3s) of the method were 3.2% and 0.4 μg L−1, respectively. The method was successfully applied to determination of Cu(II) in fish otoliths (CRM 22), bone ash (SRM 1400) and coastal seawater and estuarine water samples. PMID:24511158

  17. Graphitized carbons for solid-phase extraction.

    PubMed

    Hennion, M C

    2000-07-14

    The objective of this review is to provide updated information about the most important features of graphitized carbonaceous sorbents used for solid-phase extraction (SPE) of organic compounds from liquid natural matrices or extracts. The surface characteristics of graphitized carbon blacks and porous graphitic carbons are described which are responsible for the various types interactions (hydrophobic, electronic and ion-exchange) with analytes. The method development is given which is based on the prediction from liquid chromatographic retention data obtained using porous graphitic carbon. Emphasis is placed on their capability for trapping very polar and water-soluble analytes from aqueous samples. Comparison is made between carbon-based SPE sorbents and other reversed-phase materials such as octadecyl silicas and highly cross-linked copolymers. Especially, the difficulty encountered for the desorption of some strongly retained analytes is explained by LC data and solutions are given for optimizing the composition and volume of the desorption solution. Many examples illustrate the various common features of graphitized carbons which are the extraction of very polar analytes and multiresidue extractions. Some applications are specific to graphitized carbon black due to the presence of surface functional groups. They include the extraction of anionic compounds such as benzene and naphthalene sulfonates or acidic pesticides. Other applications are specific to porous graphitic carbon due to its flat and homogeneous surface. One example is the trace extraction of coplanar polychlorinated biphenyls (PCBs), dibenzo-p-dioxins and dibenzofurans from other PCB congeners. PMID:10941668

  18. Synthesis and application of molecularly imprinted nanoparticles combined ultrasonic assisted for highly selective solid phase extraction trace amount of celecoxib from human plasma samples using design expert (DXB) software.

    PubMed

    Arabi, Maryam; Ghaedi, Mehrorang; Ostovan, Abbas; Tashkhourian, Javad; Asadallahzadeh, Hamideh

    2016-11-01

    In this work molecular imprinted nanoparticles (MINPs) was synthesized and applied for ultrasonic assisted solid phase extraction of celecoxib (CEL) from human plasma sample following its combination by HPLC-UV. The MINPs were prepared in a non-covalent approach using methacrylic acid as monomer, CEL as template, ethylene glycol dimethacrylate as cross-linker, and 2,2-azobisisobutyronitrile (AIBN) as the initiator of polymerization. pH, volume of rinsing and eluent solvent and amount of sorbent influence on response were investigated using factorial experimental design, while optimum point was achieved and set as 250mg sorbent, pH 7.0, 1.5mL washing solvent and 2mL eluent by analysis of results according to design expert (DX) software. At above specified conditions, CEL in human plasma with complicated matrices with acceptable high recoveries (96%) and RSD% lower than 10% was quantified and estimated. The proposed MISPE-HPLC-UV method has linear responses among peak area and concentrations of CEL in the range of 0.2-2000μgL(-1), with regression coefficient of 0.98. The limit of detection (LOD) and quantification (LOQ) based on three and ten times of the noise of HPLC peaks correspond to blank solution were 0.08 and 0.18μgL(-1), respectively. PMID:27245958

  19. Preparation and Application of Nanostructure Ion-Imprinted Polymer for Selective Solid-Phase Extraction of Pb Ions in Water, Hair, and Food Samples.

    PubMed

    Dehghani Soltani, Maryam; Taher, Mohammad Ali; Behzadi, Mansoureh

    2016-09-01

    In this research, nanostructure Pb(II) ion-imprinted polymer (IIP) was prepared by formation of 1,5-diphenylthiocarbazon (dithizone) complex. Polymerization was performed via bulk polymerization, with methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the cross-linking monomer in the presence of ammonium persulfate as the initiator. To characterize the synthesized IIP, FTIR spectroscopy and field emission scanning electron microscopy were used. This polymer was used for selective preconcentration of ultra-trace amounts of Pb ions through the SPE method. The Pb ion concentration was determined by electrothermal atomic absorption spectrometry. In the optimization process, the effects of various factors, such as pH of the sample solution, type and concentration of eluent, equilibrium sorption and desorption times, and sample volume, were investigated. Under optimized conditions, the maximum sorbent capacity was 38.46 mg/g and the enrichment factor was 200. Linearity was within the range 1.0-320.0 ng/L, with good r(2) values. The LOD was 0.55 ng/L, and the intraday and interday RSD values (n = 7, 20 ng/L Pb ions) were 2.8 and 3.5%, respectively. This selective and sensitive proposed method was applied successfully to the determination of Pb in water, hair, and food samples, with high recoveries. PMID:27325007

  20. Evaluation of a molecularly imprinted polymer for determination of steroids in goat milk by matrix solid phase dispersion.

    PubMed

    Gañán, Judith; Morante-Zarcero, Sonia; Gallego-Picó, Alejandrina; Garcinuño, Rosa María; Fernández-Hernando, Pilar; Sierra, Isabel

    2014-08-01

    A molecularly imprinted polymer-matrix solid-phase dispersion methodology for simultaneous determination of five steroids in goat milk samples was proposed. Factors affecting the extraction recovery such as sample/dispersant ratio and washing and elution solvents were investigated. The molecularly imprinted polymer used as dispersant in the matrix solid-phase dispersion procedure showed high affinity to steroids, and the obtained extracts were sufficiently cleaned to be directly analyzed. Analytical separation was performed by micellar electrokinetic chromatography using a capillary electrophoresis system equipped with a diode array detector. A background electrolyte composed of borate buffer (25mM, pH 9.3), sodium dodecyl sulfate (10mM) and acetonitrile (20%) was used. The developed MIP-MSPD methodology was applied for direct determination of testosterone (T), estrone (E1), 17β-estradiol (17β-E2), 17α-ethinylestradiol (EE2) and progesterone (P) in different goat milk samples. Mean recoveries obtained ranged from 81% to 110%, with relative standard deviations (RSD)≤12%. The molecularly imprinted polymer-matrix solid-phase dispersion method is fast, selective, cost-effective and environment-friendly compared with other pretreatment methods used for extraction of steroids in milk. PMID:24881547

  1. Nanostructured carbons for solid phase extraction

    NASA Astrophysics Data System (ADS)

    Puziy, A. M.; Poddubnaya, O. I.; Gawdzik, B.; Sobiesiak, M.; Reinish, C. A.; Tsyba, M. M.; Segeda, T. P.; Danylenko, M. I.

    2010-06-01

    Nanostructured carbons have been obtained by the template method using zeolite NaY and silica gels (SG60, Fluka and ZK, POCh) as structure directing agents. Texture and porous structure of carbons were characterized by TEM, XRD and nitrogen adsorption. Surface chemistry was investigated by the potentiometric titration method. It has been shown that all carbons show developed and uniform porous structure with mean size in the micropore range (1.1 nm) for zeolite derived carbon and in the mesopore range (3.4 and 4.8 nm) for silica gel derived carbons. The BET surface area of silica gel derived carbons is in the range 1230-1280 m 2/g whereas zeolite derived carbon possesses very high BET surface area, 3000 m 2/g. Potentiometric titration showed that carbons obtained by the template method contain significant amount of acid surface groups (carboxylic, lactone/enol and phenolic) with the total amount 1.1-1.5 mmol/g. To study adsorption-desorption properties of nanostructured carbons towards phenol and chlorophenols the solid phase extraction method was used. High recoveries of chlorophenols were obtained (80-93%) at the breakthrough volumes 1700-3000 mL. The recoveries are much higher than that obtained with commercially available carbon ACC (Supelco).

  2. Supported liquid membrane-protected molecularly imprinted fibre for solid-phase microextraction of thiabendazole.

    PubMed

    Barahona, Francisco; Turiel, Esther; Martín-Esteban, Antonio

    2011-05-23

    In this work, molecularly imprinted polymer fibres (MIP-fibre) have been prepared and evaluated for solid-phase microextraction (SPME), using thiabendazole (TBZ) as template. Inherent limitations of molecular imprinted polymers, such as target recognition in aqueous media, have been solved with the use of organic supported liquid membrane (SLM) protecting the MI-SPME process. MIP-fibres were located inside a polypropylene hollow capillary and protected by an organic solvent immobilized as a thin SLM in the pores of the capillary wall. The extraction procedure involved two simultaneous processes: liquid phase microextraction using polypropylene hollow fibres (HF-LPME) of the analytes from the sample to an organic acceptor solution through a SLM; and SPME of the analytes from the organic acceptor solution to a MIP-fibre inside the polypropylene capillary. The developed methodology was optimized and applied to the extraction of TBZ form spiked orange juices. Calibration curves showed good linearity in the concentration range under study (0.01-5.00 mg L(-1)) and a regression coefficient better than 0.995 was obtained. The detection limit was 4 μg L(-1), low enough to permit the satisfactory analysis of TBZ in real samples, according to European regulation. Relative standard deviations ranged below 10%, indicating good repeatability. By this manner, the advantages of inherent selectivity of MIP SPME fibres and the enrichment and sample cleanup capability of the HF-LPME have been successfully combined into a single device. PMID:21565306

  3. [Rapid fabrication of molecularly imprinted polymer fibers for solid phase microextraction of bisphenol A].

    PubMed

    Hu, Mei; Zhang, Yijun; Yang, Jinghua; Zhou, Xiaomao; Wei, Zhuqing; Ding, Xiaoqing; Zhang, Yuping

    2015-02-01

    The rapid preparation of molecularly imprinted polymer (MIP) fibers was reported using bisphenol A (BPA) as the template molecular, acetonitrile (ACN) as the porogenic solvent, α-methacrylic acid (MAA) as the functional monomer, ethylene dimethacrylate (EDMA) as the crosslinker, and azodiisobutyronitrile (AIBN) as the thermal initiator. It was carried out within a capillary of 530 µm inner diameter (I. D.) by microwave irradiation in 7 min. The resulted BPA-MIP fibers were pushed out from the capillary, eluted in a vial and inserted in the capillary again followed by the application of the solid phase microextraction (SPME) procedure. The extraction performance was investigated in detail by varying the molar ratios between the template and the monomer (BPA/MAA), the concentration of NaCl, the extraction and desorption time, the pH value and the desorption solvents. The selectivity of the prepared MIP and non-molecularly imprinted polymer (NIP) fibers was comparatively evaluated by selecting two structurally-related compounds, phenol (P) and 4-phenylphenol (PP), and non-analogue dicyandiamide (DCD). The established method was successfully applied for the pretreatment and determination of BPA from beverage samples coupled to high performance liquid chromatography (HPLC). Under the optimal conditions, the linear range of BPA was 10-400 µg/L; the detection limit (LOD) was 0.45 µg/L and the recoveries spiked in the mineral water were 88.4%-102. 8%. The results demonstrated that the developed method can determine BPA in real samples with some advantages of simple pretreatment, rapid analysis, low limit of detection and low consumption of materials. PMID:25989683

  4. Synthesis of metronidazole-imprinted molecularly imprinted polymers by distillation precipitation polymerization and their use as a solid-phase adsorbent and chromatographic filler.

    PubMed

    Liu, Jiang; Zhang, Lu; Li Han Song, Le; Liu, Yuan; Tang, Hui; Li, Yingchun

    2015-04-01

    Metronidazole-imprinted polymers with superior recognition properties were prepared by a novel strategy called distillation-precipitation polymerization. The as-obtained polymers were characterized by Fourier-transform infrared spectroscopy, laser particle size determination and scanning electron microscopy, and their binding performances were evaluated in detail by static, kinetic and dynamic rebinding tests, and Scatchard analysis. The results showed that when the fraction of the monomers was 5 vol% in the whole reaction system, the prepared polymers afforded good morphology, monodispersity, and high adsorption capacity and excellent selectivity to the target molecule, metronidazole. The optimal binding performance is 12.41 mg/g for metronidazole just before leakage occurred and 38.51 mg/g at saturation in dynamic rebinding tests. Metronidazole-imprinted polymers were further applied as packing agents in solid-phase extraction and as chromatographic filler, both of which served for the detection of metronidazole in fish tissue. The results illustrated the recoveries of spiked samples ranged from 82.97 to 87.83% by using molecularly imprinted solid-phase extraction combined with a C18 commercial column and 93.7 to 101.2% by directly using the polymer-packed chromatographic column. The relative standard deviation of both methods was less than 6%. PMID:25594306

  5. Novel molecularly-imprinted solid-phase microextraction fiber coupled with gas chromatography for analysis of furan.

    PubMed

    Hashemi-Moghaddam, Hamid; Ahmadifard, Mojtaba

    2016-04-01

    This study combined a molecularly-imprinted polymer with headspace solid-phase microextraction (HS-SPME). Preparation of molecularly-imprinted polymer is not effective for volatile compounds. To overcome this limitation, pyrrole was chosen as a template for the preparation of the furan-imprinted polymer. The holes in the synthesized polymer were suitable for furan adsorption because the chemical structure of pyrrole is similar to that of furan. The extraction properties of the fiber to furan were examined using an HS-SPME device coupled with gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The effects of the extraction parameters of exposure time, sampling temperature, and salt concentration on extraction efficiency were studied. Satisfactory reproducibility was obtained for extractions from spiked water samples at RSD<7.5% (n=5). The calibration graphs were linear at 0.5-100 ng ml(-1) and the detection limit for furan was 0.042 ng ml(-1). The fabricated fiber was successfully applied for headspace extraction of furan from tap water and canned tuna as shown by GC-MS analysis. PMID:26838393

  6. Solid-phase extraction in segmented flow.

    PubMed

    Rendl, Martin; Brandstetter, Thomas; Rühe, Jürgen

    2014-11-01

    Two-phase flow systems are increasingly popular for miniaturized, high-throughput performance of analytical or chemical reactions. In this contribution, we extend a previously described method that allows to increase the range of applications of heterogeneous reactions in two-phase flow, i.e., reactions that rely on isolation and purification of the compound of interest for downstream analysis. Our concept is based on liquid plugs, which serve as miniaturized compartments for the analytical reactions. Purification of the target compound is achieved by extracting the analyte from the aqueous compartments using magnetic beads as solid carriers. In the present paper, we elucidate the influence of parameters such as the polarity of the liquid/liquid and solid/liquid interfaces, the magnetic forces and the fluidic conditions onto the extraction performance. The conditions for reliable extraction and purification of the target compounds are determined. Furthermore, we investigate how to facilitate breaking of the plugs through reduction of the surface tension of the solid/liquid interface. When a lower surface tension is employed, a smaller number of beads is required for the extraction process, which implies a higher sensitivity of the device. In addition, we generate channels with different surface chemistries, which are able to manipulate the flow of the two immiscible liquids. We describe a very simple way to generate such devices and show that we can achieve a transition from segmented flow of plugs to a side-by side flow of the two immiscible liquids, a key requirement for the purification of the compounds. PMID:25300748

  7. Formation of target-specific binding sites in enzymes: solid-phase molecular imprinting of HRP

    NASA Astrophysics Data System (ADS)

    Czulak, J.; Guerreiro, A.; Metran, K.; Canfarotta, F.; Goddard, A.; Cowan, R. H.; Trochimczuk, A. W.; Piletsky, S.

    2016-05-01

    Here we introduce a new concept for synthesising molecularly imprinted nanoparticles by using proteins as macro-functional monomers. For a proof-of-concept, a model enzyme (HRP) was cross-linked using glutaraldehyde in the presence of glass beads (solid-phase) bearing immobilized templates such as vancomycin and ampicillin. The cross-linking process links together proteins and protein chains, which in the presence of templates leads to the formation of permanent target-specific recognition sites without adverse effects on the enzymatic activity. Unlike complex protein engineering approaches commonly employed to generate affinity proteins, the method proposed can be used to produce protein-based ligands in a short time period using native protein molecules. These affinity materials are potentially useful tools especially for assays since they combine the catalytic properties of enzymes (for signaling) and molecular recognition properties of antibodies. We demonstrate this concept in an ELISA-format assay where HRP imprinted with vancomycin and ampicillin replaced traditional enzyme-antibody conjugates for selective detection of templates at micromolar concentrations. This approach can potentially provide a fast alternative to raising antibodies for targets that do not require high assay sensitivities; it can also find uses as a biochemical research tool, as a possible replacement for immunoperoxidase-conjugates.Here we introduce a new concept for synthesising molecularly imprinted nanoparticles by using proteins as macro-functional monomers. For a proof-of-concept, a model enzyme (HRP) was cross-linked using glutaraldehyde in the presence of glass beads (solid-phase) bearing immobilized templates such as vancomycin and ampicillin. The cross-linking process links together proteins and protein chains, which in the presence of templates leads to the formation of permanent target-specific recognition sites without adverse effects on the enzymatic activity. Unlike

  8. Formation of target-specific binding sites in enzymes: solid-phase molecular imprinting of HRP.

    PubMed

    Czulak, J; Guerreiro, A; Metran, K; Canfarotta, F; Goddard, A; Cowan, R H; Trochimczuk, A W; Piletsky, S

    2016-06-01

    Here we introduce a new concept for synthesising molecularly imprinted nanoparticles by using proteins as macro-functional monomers. For a proof-of-concept, a model enzyme (HRP) was cross-linked using glutaraldehyde in the presence of glass beads (solid-phase) bearing immobilized templates such as vancomycin and ampicillin. The cross-linking process links together proteins and protein chains, which in the presence of templates leads to the formation of permanent target-specific recognition sites without adverse effects on the enzymatic activity. Unlike complex protein engineering approaches commonly employed to generate affinity proteins, the method proposed can be used to produce protein-based ligands in a short time period using native protein molecules. These affinity materials are potentially useful tools especially for assays since they combine the catalytic properties of enzymes (for signaling) and molecular recognition properties of antibodies. We demonstrate this concept in an ELISA-format assay where HRP imprinted with vancomycin and ampicillin replaced traditional enzyme-antibody conjugates for selective detection of templates at micromolar concentrations. This approach can potentially provide a fast alternative to raising antibodies for targets that do not require high assay sensitivities; it can also find uses as a biochemical research tool, as a possible replacement for immunoperoxidase-conjugates. PMID:27174700

  9. Advances in solid-phase extraction disks for environmental chemistry

    USGS Publications Warehouse

    Thurman, E.M.; Snavely, K.

    2000-01-01

    The development of solid-phase extraction (SPE) for environmental chemistry has progressed significantly over the last decade to include a number of new sorbents and new approaches to SPE. One SPE approach in particular, the SPE disk, has greatly reduced or eliminated the use of chlorinated solvents for the analysis of trace organic compounds. This article discusses the use and applicability of various SPE disks, including micro-sized disks, prior to gas chromatography-mass spectrometry for the analysis of trace organic compounds in water. Copyright (C) 2000 Elsevier Science B.V.

  10. Analysis of malachite green in aquatic products by carbon nanotube-based molecularly imprinted - matrix solid phase dispersion.

    PubMed

    Wang, Yu; Chen, Ligang

    2015-10-01

    A simple method based on matrix solid phase dispersion (MSPD) using molecularly imprinted polymers (MIPs) as sorbents for selective extraction of malachite green (MG) from aquatic products was developed. The MIPs were prepared by using carbon nanotube as support, MG as template, methacrylic acid as functional monomer, ethyleneglycol dimethacrylate as crosslinker and methylene chloride as solvent. The MIPs were characterized by Fourier transform infrared spectrometry and transmission electron microscopy. The isothermal adsorption, kinetics absorption and selective adsorption experiments were carried out. We optimized the extraction conditions as follows: the ratio of MIPs to sample was 2:3, the dispersion time was 15min, washing solvent was 4mL 50% aqueous methanol and elution solvent was 3mL methanol-acetic acid (98: 2, v/v). Once the MSPD process was completed, the MG extracted from aquatic products was determined by high performance liquid chromatography. The detection limit of MG was 0.7μgkg(-1). The relative standard deviations of intra-day and inter-day were obtained in the range of 0.9%-4.7% and 3.4%-9.8%, respectively. In order to evaluate the applicability and reliability of the proposed method, it was applied to determine MG in different aquatic products samples including fish, shrimp, squid and crabs. The satisfied recoveries were in the range of 89.2%-104.6%. The results showed that this method is faster, simpler and makes extraction and purification in the same system. PMID:26319302

  11. A simple approach for the preparation of simazine molecularly imprinted nanofibers via self-polycondensation for selective solid-phase microextraction.

    PubMed

    Saraji, Mohammad; Mehrafza, Narges

    2016-09-14

    A novel molecularly imprinted sol-gel material based on polysiloxane nanofiber was introduced as a solid-phase microextraction coating on a stainless steel wire for the extraction of simazine. The nanostructured molecularly imprinted fiber was prepared by a simple single step method at room temperature, using methyltriethoxysilane as the sol-gel precursor and simazine as the template molecule. The fiber was applied for the extraction of simazine in different water samples followed by gas chromatography and mass spectrometry detection. The extraction capacity of the molecularly imprinted fiber was 8 ng, and it had better extraction efficiency than the non-imprinted fiber and commercial fibers (PDMS and PA). The fiber had also a good selectivity for simazine and its analogous compounds. Important parameters affecting the extraction and desorption efficiency, such as salt concentration, stirring rate, pH of sample solution, extraction time and temperature, temperature and time of desorption, were investigated. The intra- and inter-day relative standard deviations were in the range of 4.3-7.6%. The fiber-to-fiber reproducibility was 7.7-8.5%. The method showed a good linearity (r(2)> 0.9980) in the range of 0.02-20 μg L(-1) with the detection limit of 0.005 μg L(-1). The relative recoveries were also in the range of 94-97% for different water samples. PMID:27566345

  12. Preparation of a pipette tip-based molecularly imprinted solid-phase microextraction monolith by epitope approach and its application for determination of enkephalins in human cerebrospinal fluid.

    PubMed

    Li, Hua; Li, Dan

    2015-11-10

    In this study, a novel molecularly imprinted polymer (MIP) monolith for highly selective extraction of enkephalins was synthesized and prepared in a micropipette tip using epitope imprinting technique. The synthesized MIPs were characterized by scanning electron microscope (SEM) and infrared spectroscopy. A molecularly imprinted solid-phase microextraction (MISPME) method was developed for extraction of enkephalins in aqueous solutions. The parameters affecting MISPME were optimized. The results indicated that this MIP monolith exhibited specific recognition capability, high enrichment efficiency and excellent reusability for enkephalins. MALDI-TOF MS analysis demonstrated that this MIP monolith can act as a useful tool for highly selective purification and enrichment of enkephalin, a kind of low abundance protein, from high-abundance proteins in human cerebrospinal fluids (CSF). Employed this MIP monolith as solid-phase microextraction column, quantitative assay of enkephalins in human CSF was developed by HPLC-ultraviolet (UV) detection in this work. The detection limits were 0.05-0.08nM. This MISPME/HPLC-UV method was used to quantify Met-enkephalin and Leu-enkephalin levels in the CSF of patients with cancer pain. PMID:26263061

  13. Ferrofluid-based dispersive solid phase extraction of palladium.

    PubMed

    Farahani, Malihe Davudabadi; Shemirani, Farzaneh; Gharehbaghi, Maysam

    2013-05-15

    A new mode of dispersive solid phase extraction based on ferrofluid has been developed. In this method, an appropriate amount of ferrofluid is injected rapidly into the aqueous sample by a syringe. Since the sorbent is highly dispersed in the aqueous phase, extraction can be achieved within a few seconds. The ferrofluid can be attracted by a magnet and no centrifugation step is needed for phase separation. Palladium was used as a model compound in the development and evaluation of the extraction procedure in combination with flame atomic absorption spectrometry. The experimental parameters (pH, DDTC concentration, type and concentration of eluent, the amount of adsorbent, extraction time, and the effect of interfering ions) were investigated in detail. Under the optimized conditions, the calibration graph was linear over the range of 1-100 μg L(-1) and relative standard deviation of 3.3% at 0.1 μg mL(-1) was obtained (n=7). The limit of detection and enrichment factor (EF) was obtained to be 0.35 μg L(-1) and 267, respectively. The maximum adsorption capacity of the adsorbent at optimum conditions was found to be 24.6 mg g(-1) for Pd(II). The method was validated using certified reference material, and has been applied for the determination of trace Pd(II) in actual samples with satisfactory results. PMID:23618148

  14. Nanometer-sized materials for solid-phase extraction of trace elements.

    PubMed

    Hu, Bin; He, Man; Chen, Beibei

    2015-04-01

    This review presents a comprehensive update on the state-of-the-art of nanometer-sized materials in solid-phase extraction (SPE) of trace elements followed by atomic-spectrometry detection. Zero-dimensional nanomaterials (fullerene), one-dimensional nanomaterials (carbon nanotubes, inorganic nanotubes, and nanowires), two-dimensional nanomaterials (nanofibers), and three-dimensional nanomaterials (nanoparticles, mesoporous nanoparticles, magnetic nanoparticles, and dendrimers) for SPE are discussed, with their application for trace-element analysis and their speciation in different matrices. A variety of other novel SPE sorbents, including restricted-access sorbents, ion-imprinted polymers, and metal-organic frameworks, are also discussed, although their applications in trace-element analysis are relatively scarce so far. PMID:25577358

  15. New methods and materials for solid phase extraction and high performance liquid chromatography

    SciTech Connect

    Dumont, P.J.

    1996-04-23

    This paper describes methods for solid phase extraction and high performance liquid chromatography (HPLC). The following are described: Effects of Resin Sulfonation on the Retention of Polar Organic Compounds in Solid Phase Extraction; Ion-Chromatographic Separation of Alkali Metals In Non-Aqueous Solvents; Cation-Exchange Chromatography in Non-Aqueous Solvents; and Silicalite As a Stationary Phase For HPLC.

  16. Novel materials and methods for solid-phase extraction and liquid chromatography

    SciTech Connect

    Ambrose, D.

    1997-06-24

    This report contains a general introduction which discusses solid-phase extraction and solid-phase micro-extraction as sample preparation techniques for high-performance liquid chromatography, which is also evaluated in the study. This report also contains the Conclusions section. Four sections have been removed and processed separately: silicalite as a sorbent for solid-phase extraction; a new, high-capacity carboxylic acid functionalized resin for solid-phase extraction; semi-micro solid-phase extraction of organic compounds from aqueous and biological samples; and the high-performance liquid chromatographic determination of drugs and metabolites in human serum and urine using direct injection and a unique molecular sieve.

  17. COMPARATIVE YIELDS OF MUTAGENS FROM CIGARETTE SMOKERS' URINE OBTAINED BY USING SOLID-PHASE EXTRACTION TECHNIQUES

    EPA Science Inventory

    Urine from cigarette smokers was prepared for mutagenicity testing by extracting mutagens with solid phase extraction columns. ommercially available prepacked bonded silicas (cotadecyl, cyclohexyl, cyanopropyl) were compared for their efficiency and specificity in concentration o...

  18. Molecularly Imprinted Nanomicrospheres as Matrix Solid-Phase Dispersant Combined with Gas Chromatography for Determination of Four Phosphorothioate Pesticides in Carrot and Yacon

    PubMed Central

    Zhou, Mengchun; Hu, Nana; Shu, Shaohua; Wang, Mo

    2015-01-01

    An efficient, rapid, and selective method for sample pretreatment, namely, molecularly imprinted matrix solid-phase dispersion (MI-MSPD) coupled with gas chromatography (GC), was developed for the rapid isolation of four phosphorothioate organophosphorus pesticides (tolclofos-methyl, phoxim, chlorpyrifos, and parathion-methyl) from carrot and yacon samples. New molecularly imprinted polymer nanomicrospheres were synthesized by using typical structural analogue tolclofos-methyl as a dummy template via surface grafting polymerization on nanosilica. Then, these four pesticides in carrot and yacon were extracted and adsorbed using the imprinted nanomicrospheres and further determined by gas chromatography. Under the optimized conditions, a good linearity of four pesticides was obtained in a range of 0.05–17.0 ng·g−1 with R varying from 0.9971 to 0.9996, and the detection limit of the method was 0.012~0.026 ng·g−1 in carrot and yacon samples. The recovery rates at two spiked levels were in the range of 85.4–105.6% with RSD ≤9.6%. The presented MI-MSPD method combined the advantages of MSPD for allowing the extraction, dispersion, and homogenization in two steps and the advantages of MIPs for high affinity and selectivity towards four phosphorothioate pesticides, which could be applied to the determination of pesticide residues in complicated vegetal samples. PMID:25954569

  19. Molecularly imprinted nanomicrospheres as matrix solid-phase dispersant combined with gas chromatography for determination of four phosphorothioate pesticides in carrot and yacon.

    PubMed

    Zhou, Mengchun; Hu, Nana; Shu, Shaohua; Wang, Mo

    2015-01-01

    An efficient, rapid, and selective method for sample pretreatment, namely, molecularly imprinted matrix solid-phase dispersion (MI-MSPD) coupled with gas chromatography (GC), was developed for the rapid isolation of four phosphorothioate organophosphorus pesticides (tolclofos-methyl, phoxim, chlorpyrifos, and parathion-methyl) from carrot and yacon samples. New molecularly imprinted polymer nanomicrospheres were synthesized by using typical structural analogue tolclofos-methyl as a dummy template via surface grafting polymerization on nanosilica. Then, these four pesticides in carrot and yacon were extracted and adsorbed using the imprinted nanomicrospheres and further determined by gas chromatography. Under the optimized conditions, a good linearity of four pesticides was obtained in a range of 0.05-17.0 ng·g(-1) with R varying from 0.9971 to 0.9996, and the detection limit of the method was 0.012~0.026 ng·g(-1) in carrot and yacon samples. The recovery rates at two spiked levels were in the range of 85.4-105.6% with RSD ≤9.6%. The presented MI-MSPD method combined the advantages of MSPD for allowing the extraction, dispersion, and homogenization in two steps and the advantages of MIPs for high affinity and selectivity towards four phosphorothioate pesticides, which could be applied to the determination of pesticide residues in complicated vegetal samples. PMID:25954569

  20. Preparation and application of a novel molecularly imprinted solid-phase microextraction monolith for selective enrichment of cholecystokinin neuropeptides in human cerebrospinal fluid.

    PubMed

    Ji, Xiang; Li, Dan; Li, Hua

    2015-08-01

    A novel molecularly imprinted polymer (MIP) monolith for highly selective extraction of cholecystokinin (CCK) neuropeptides was prepared in a micropipette tip. The MIPs were synthesized by epitope imprinting technique and the polymerization conditions were investigated and optimized. The synthesized MIPs were characterized by infrared spectroscopy, elemental analyzer and scanning electron microscope. A molecularly imprinted solid-phase microextraction (MI-μ-SPE) method was developed for the extraction of CCK neuropeptides in aqueous solutions. The parameters affecting MI-μ-SPE were optimized. The results indicated that this MIP monolith exhibited specific recognition capability and high enrichment efficiency for CCK neuropeptides. In addition, it showed excellent reusability. This MIP monolith was used for desalting and enrichment of CCK4, CCK5 and CCK8 from human cerebrospinal fluid prior to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis, and the results show that this MIP monolith can be a useful tool for effective purification and highly selective enrichment of multiple homologous CCK neuropeptides in cerebrospinal fluid simultaneously. By employing MI-μ-SPE combined with HPLC-ESI-MS/MS analysis, endogenous CCK4 in human cerebrospinal fluid was quantified. PMID:25616243

  1. Evaluation of a new method for chemical coating of aluminum wire with molecularly imprinted polymer layer. Application for the fabrication of triazines selective solid-phase microextraction fiber.

    PubMed

    Djozan, Djavanshir; Ebrahimi, Bahram; Mahkam, Mehrdad; Farajzadeh, Mir Ali

    2010-07-26

    A new solid-phase microextraction (SPME) fiber is fabricated through ultra violet irradiation polymerization of ametryn-molecularly imprinted polymer on the surface of anodized-silylated aluminum wire. The prepared fiber is durable with very good chemical and thermal stability which can be coupled to GC and GC/MS. The effective parameters on the fabrication and application procedures such as spraying mode, ultra violet irradiation (polymerization) time, number of sprayings and polymerizations, pH and ionic strength of sample and extraction time were optimized. This fiber shows high selectivity with great extraction capacity toward triazines. SPME and GC analysis of ametryn, prometryn, terbutryn, atrazine, simazine, propazine and cyanazine using the fabricated fiber result in the detection limits of 9, 32, 27, 43, 51, 74 and 85 ng mL(-1), respectively. The reliability of the prepared fiber in real samples has been investigated and proved by using spiked tap water, rice, maize and onion samples. PMID:20638497

  2. Solid-Phase Synthesis of Molecularly Imprinted Polymer Nanoparticles with a Reusable Template – “Plastic Antibodies”

    PubMed Central

    Poma, Alessandro; Guerreiro, Antonio; Whitcombe, Michael J.; Piletska, Elena V.; Turner, Anthony P.F.; Piletsky, Sergey A.

    2016-01-01

    Molecularly Imprinted Polymers (MIPs) are generic alternatives to antibodies in sensors, diagnostics and separations. To displace biomolecules without radical changes in infrastructure in device manufacture, MIPs should share their characteristics (solubility, size, specificity and affinity, localized binding domain) whilst maintaining the advantages of MIPs (low-cost, short development time and high stability) hence the interest in MIP nanoparticles. Herein we report a reusable solid-phase template approach (fully compatible with automation) for the synthesis of MIP nanoparticles and their precise manufacture using a prototype automated UV photochemical reactor. Batches of nanoparticles (30-400 nm) with narrow size distributions imprinted with: melamine (d = 60 nm, Kd = 6.3 × 10−8 m), vancomycin (d = 250 nm, Kd = 3.4 × 10−9 m), a peptide (d = 350 nm, Kd = 4.8 × 10−8 m) and proteins have been produced. Our instrument uses a column packed with glass beads, bearing the template. Process parameters are under computer control, requiring minimal manual intervention. For the first time we demonstrate the reliable re-use of molecular templates in the synthesis of MIPs (≥ 30 batches of nanoMIPs without loss of performance). NanoMIPs are produced template-free and the solid-phase acts both as template and affinity separation medium. PMID:26869870

  3. Optimization of solid-phase extraction using developed modern sorbent for trace determination of ametryn in environmental matrices.

    PubMed

    Koohpaei, A R; Shahtaheri, S J; Ganjali, M R; Forushani, A Rahimi; Golbabaei, F

    2009-10-30

    In recent years, there has been a significant increase in molecularly imprinted solid-phase extraction (MISPE) technique for the purification and clean-up of environmental samples. In this study, solid-phase extraction using the imprinted polymer has been optimized with the experimental design approach for a triazine herbicide, named ametryn with regard to the critical factors such as sample pH, sample concentration, sample flow-rate, sample volume, elution solvent, washing solvent and sorbent mass. These factors were evaluated statistically and also validated with spiked drinking water samples and showed a good reproducibility over six consecutive days as well as six within-day experiments. Also, in order to the evaluate efficiency of the optimized MISPE protocols, enrichment capacity, reusability and cross-reactivity of cartridges have been studied. Finally, a selective MISPE was successfully demonstrated for ametryn with a recovery of above 90% for spiked drinking water samples. It was concluded that the central composite design could prove beneficial for aiding the MIP and MISPE development. PMID:19573983

  4. GAS PHASE EXPOSURE HISTORY DERIVED FROM MATERIAL PHASE CONCENTRATION PROFILES USING SOLID PHASE MICRO-EXTRACTION

    EPA Science Inventory

    EPA Identifier: F8P31059
    Title: Gas Phase Exposure History Derived from Material Phase Concentration Profiles Using Solid Phase Micro-Extraction
    Fellow (Principal Investigator): Jonathan Lewis McKinney
    Institution: University of Missouri - ...

  5. Development of dummy molecularly imprinted based on functionalized silica nanoparticles for determination of acrylamide in processed food by matrix solid phase dispersion.

    PubMed

    Arabi, Maryam; Ghaedi, Mehrorang; Ostovan, Abbas

    2016-11-01

    A novel technique was applied for the synthesis of dummy molecularly imprinted silica nanoparticles (DMISNPs). DMISNPs were characterized by Fourier transmission infrared spectrometry, scanning electron microscopy and transmission electron microscope. The material was used as dispersant for the analysis of biscuit and bread samples using matrix solid phase dispersion (MSPD). Of advantages of such approach may be counted as the simplicity of synthesis procedure, low consumption of organic solvent, mild working temperature during the synthesis, high binding capacity and affinity. The effect of various parameters such as sample-to-dispersant ratio and eluents volume on extraction recovery was investigated and optimized by central composite design under response surface methodology. It was proven that the proposed dispersant leads to high affinity toward acrylamide even in complicated matrices. Quantification of the acrylamide was carried out by high performance liquid chromatography with UV detection (HPLC-UV). PMID:27211623

  6. Preparation and evaluation of solid-phase microextraction fiber based on molecularly imprinted polymers for trace analysis of tetracyclines in complicated samples.

    PubMed

    Hu, Xiaogang; Pan, Jialiang; Hu, Yuling; Huo, Yin; Li, Gongke

    2008-04-25

    Molecularly imprinted polymer (MIP) is widely used in many fields because of its characteristics of high selectivity, chemical stability and easy preparation. To enhance the selectivity and applicability of solid-phase microextraction (SPME), a novel MIP-coated SPME fiber was firstly prepared by multiple co-polymerization method with tetracycline as template. It could be coupled directly to high-performance liquid chromatography (HPLC) and used for trace analysis of tetracyclines (TCs) in complicated samples. The characteristics and application of the fibers were investigated. The electron microscope provided a crosslinked and porous surface, and the average thickness of the MIP coating was 19.5 microm. Compared with the non-imprinted polymer (NIP) coated fibers, the special selectivity to tetracycline and structure-similar oxytetracycline, doxycycline, chlortetracycline were discovered with the MIP-coated fibers. The adsorption and desorption of TCs with the MIP-coated fiber could be achieved quickly. A method for the fluorimetric determination of four TCs by the MIP-coated SPME coupled with HPLC was developed. The optimized extraction conditions such as extraction solvent, desorption solvent, and stirring speed were studied. Linear ranges for the four TCs were 5.00-200 microg/L and detection limits were within the range of 1.0-2.3 microg/L. The method was applied to simultaneous multi-residue analysis of four TCs in the spiked chicken feed, chicken muscle, and milk samples with the satisfactory recoveries. PMID:18325526

  7. Molecularly imprinted matrix solid-phase dispersion coupled to micellar electrokinetic chromatography for simultaneous determination of triazines in soil, fruit, and vegetable samples.

    PubMed

    Wen, Yingying; Chen, Lingxin; Li, Jinhua; Ma, Yanling; Xu, Shoufang; Zhang, Zhong; Niu, Zongliang; Choo, Jaebum

    2012-08-01

    A simple and sensitive method for the simultaneous determination of four triazines from soil, strawberry, and tomato samples was developed by selective molecularly imprinted matrix solid-phase dispersion (MI-MSPD) coupled to micellar electrokinetic chromatography (MEKC). Using atrazine as template, the synthesized molecularly imprinted polymers (MIPs) were employed as the dispersion sorbent of MSPD to successfully extract atrazine and its analogs of simazine, ametryn, and propazine from the three different real samples, while matrix interferences were effectively eliminated simultaneously under the optimum extraction conditions. Excellent separation was achieved within 7 min by using an optimized buffer system composed of 30 mmol/L ammonium acetate, 20 mmol/L SDS, and 15% ACN at pH 9.45, obtained by orthogonal design. Good linearity was obtained in a range of 0.5-25 μg/g with the correlation coefficients R(2) ≥0.9991 except for strawberry sample within 1-25 μg/g, and limits of detection were between 12.9-31.5 ng/g in all the three samples. The average recoveries of the four triazines at three different spiked levels were ranged from 53.5 to 98.4% with the relative standard deviations of 1.28-4.89%. This method was proved convenient, costeffective, and environmental benign and could be used as an alternative tool to the existing methods for analyzing the residues of triazines in soil, fruit, and vegetable samples. PMID:22887168

  8. Molecularly imprinted polymer for the selective extraction of luteolin from Chrysanthemum morifolium Ramat.

    PubMed

    Gao, Die; Yang, Fengqing; Xia, Zhining; Zhang, Qihui

    2016-08-01

    In this work, luteolin-imprinted polymers were prepared by noncovalent precipitation polymerization for the first time. Their structural features and morphologies were analyzed by using Fourier transform infrared spectroscopy and scanning electron microscopy, respectively. The adsorption experiments revealed that the luteolin-imprinted polymers presented high selective recognition property to luteolin. The selectivity experiment showed that the adsorption capacity and selectivity of polymers to luteolin was higher than that of three structural analogs, including quercetin, isorhamnetin, and ombuin. Furthermore, an efficient method based on luteolin-imprinted polymers coupled with solid-phase extraction was developed for the pretreatment of luteolin from Chrysanthemum morifolium Ramat. The results demonstrated that the luteolin-imprinted polymers coupled with solid phase extraction method was proven to be a potentially competitive technique for the separation and enrichment of luteolin in complex samples such as Chinese patent medicines and biological samples. PMID:27288270

  9. Selective extraction and concentration of mebendazole in seawater samples using molecularly imprinted polymer as sorbent.

    PubMed

    Lian, Ziru; Liang, Zhenlin; Wang, Jiangtao

    2015-02-15

    A high selective pre-treatment method for the extraction and analysis of mebendazole in environmental water samples was developed based on molecularly imprinted solid-phase extraction (MISPE). The mebendazole imprinted polymers were synthesized in acetonitrile using methacrylic acid and ethylene glycol dimethacrylate as functional monomer and cross-linker respectively. The imprinted materials showed high adsorption ability for mebendazole and were applied as special solid-phase extraction sorbents for selective separation of mebendazole. An off-line MISPE procedure was developed for the purification and enrichment of mebendazole from natural seawater samples prior to high-performance liquid chromatography analysis. The recoveries of spiked seawater on the MISPE cartridges were from 83.0% to 90.6%, and the values of the relative standard deviation were in the range of 2.78-4.13% (n=3). The satisfied results showed that this pre-treatment methodology for extracting mebendazole in seawater was simple and effective. PMID:25547616

  10. Selective enrichment of phenols from coal liquefaction oil by solid phase extraction method

    SciTech Connect

    Tian, M.; Feng, J.

    2009-07-01

    This study focuses on the solid phase extraction method for the enrichment and separation of phenol from coal liquefaction oil. The phenols' separation efficiency was compared on different solid phase extraction (SPE) cartridges, and the effect of solvents with different polarity and solubility parameter on amino-bonded silica was compared for selection of optimal elution solution. The result showed that amino-bonded silica has the highest selectivity and best extraction capability due to two factors, weak anion exchange adsorption and polar attraction adsorption.

  11. Solid phase microextraction of diclofenac using molecularly imprinted polymer sorbent in hollow fiber combined with fiber optic-linear array spectrophotometry

    NASA Astrophysics Data System (ADS)

    Pebdani, Arezou Amiri; Shabani, Ali Mohammad Haji; Dadfarnia, Shayessteh; Khodadoust, Saeid

    2015-08-01

    A simple solid phase microextraction method based on molecularly imprinted polymer sorbent in the hollow fiber (MIP-HF-SPME) combined with fiber optic-linear array spectrophotometer has been applied for the extraction and determination of diclofenac in environmental and biological samples. The effects of different parameters such as pH, times of extraction, type and volume of the organic solvent, stirring rate and donor phase volume on the extraction efficiency of the diclofenac were investigated and optimized. Under the optimal conditions, the calibration graph was linear (r2 = 0.998) in the range of 3.0-85.0 μg L-1 with a detection limit of 0.7 μg L-1 for preconcentration of 25.0 mL of the sample and the relative standard deviation (n = 6) less than 5%. This method was applied successfully for the extraction and determination of diclofenac in different matrices (water, urine and plasma) and accuracy was examined through the recovery experiments.

  12. Solid-phase extraction of plant thionins employing aluminum silicate based extraction columns.

    PubMed

    Hussain, Shah; Güzel, Yüksel; Pezzei, Cornelia; Rainer, Matthias; Huck, Christian W; Bonn, Günther K

    2014-08-01

    Thionins belong to a family of cysteine-rich, low-molecular-weight (∼5 KDa) biologically active proteins in the plant kingdom. They display a broad cellular toxicity against a wide range of organisms and eukaryotic cell lines. Thionins protect plants against different pathogens, including bacteria and fungi. A highly selective solid-phase extraction method for plant thionins is reported deploying aluminum silicate (3:2 mullite) powder as a sorbent in extraction columns. Mullite was shown to considerably improve selectivity compared to a previously described zirconium silicate embedded poly(styrene-co-divinylbenzene) monolithic polymer. Due to the presence of aluminum(III), mullite offers electrostatic interactions for the selective isolation of cysteine-rich proteins. In comparison to zirconium(IV) silicate, aluminum(III) silicate showed reduced interactions towards proteins which resulted into superior washings of unspecific compounds while still retaining cysteine-rich thionins. In the presented study, European mistletoe, wheat and barley samples were subjected to solid-phase extraction analysis for isolation of viscotoxins, purothionins and hordothionins, respectively. Matrix-assisted laser desorption/ionization time of flight mass spectroscopy was used for determining the selectivity of the sorbent toward thionins. The selectively retained thionins were quantified by colorimetric detection using the bicinchoninic acid assay. For peptide mass-fingerprint analysis tryptic digests of eluates were examined. PMID:24913248

  13. Automated extraction of acetylgestagens from kidney fat by matrix solid phase dispersion.

    PubMed

    Rosén, J; Hellenäs, K E; Törnqvist, P; Shearan, P

    1994-12-01

    A new extraction method for the acetylgestagens medroxyprogesterone acetate (MPA), chloromadinone acetate and megestrol acetate, from kidney fat, has been developed. The method is a combination of matrix solid phase dispersion and solid phase extraction and is simpler and safer than previous methods, especially as it can be automated. The recovery was estimated as 59 +/- 5% (mean +/- standard deviation) for MPA. For screening purposes detection can be achieved using a commercially available enzyme immunoassay kit giving detection limits in the range of 1.0-2.0 ng g-1. PMID:7533481

  14. Detection of ibuprofen and ciprofloxacin by solid-phase extraction and UV/Vis spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhou, Zhengwei; Jiang, Jia Qian

    2012-07-01

    A simple and economic solid-phase extraction coupled with UV/Vis spectrophotometric method is described for the analysis of ibuprofen and ciprofloxacin. Following solid-phase extraction from model wastewater samples containing standard ibuprofen or ciprofloxacin, elutes were analyzed by a UV/Vis spectrophotometer at 225 nm for ibuprofen and 280 nm for ciprofloxacin. The assay was linear for both compounds with good coefficients of correlation. This method shows good recoveries for both compounds with 101.0 ± 9.8% for ibuprofen and 99.4 ± 11.8% ciprofloxacin.

  15. Characterization of rhamnolipids by liquid chromatography/mass spectrometry after solid-phase extraction.

    PubMed

    Behrens, Beate; Engelen, Jeannine; Tiso, Till; Blank, Lars Mathias; Hayen, Heiko

    2016-04-01

    Rhamnolipids are surface-active agents with a broad application potential that are produced in complex mixtures by bacteria of the genus Pseudomonas. Analysis from fermentation broth is often characterized by laborious sample preparation and requires hyphenated analytical techniques like liquid chromatography coupled to mass spectrometry (LC-MS) to obtain detailed information about sample composition. In this study, an analytical procedure based on chromatographic method development and characterization of rhamnolipid sample material by LC-MS as well as a comparison of two sample preparation methods, i.e., liquid-liquid extraction and solid-phase extraction, is presented. Efficient separation was achieved under reversed-phase conditions using a mixed propylphenyl and octadecylsilyl-modified silica gel stationary phase. LC-MS/MS analysis of a supernatant from Pseudomonas putida strain KT2440 pVLT33_rhlABC grown on glucose as sole carbon source and purified by solid-phase extraction revealed a total of 20 congeners of di-rhamnolipids, mono-rhamnolipids, and their biosynthetic precursors 3-(3-hydroxyalkanoyloxy)alkanoic acids (HAAs) with different carbon chain lengths from C8 to C14, including three rhamnolipids with uncommon C9 and C11 fatty acid residues. LC-MS and the orcinol assay were used to evaluate the developed solid-phase extraction method in comparison with the established liquid-liquid extraction. Solid-phase extraction exhibited higher yields and reproducibility as well as lower experimental effort. Graphical Abstract ᅟ. PMID:26879646

  16. Preparation of molecularly imprinted polymeric fibers using a single bifunctional monomer for the solid-phase microextraction of parabens from environmental solid samples.

    PubMed

    Díaz-Álvarez, Myriam; Smith, Stephen P; Spivak, David A; Martín-Esteban, Antonio

    2016-02-01

    In this study, molecularly imprinted polymer fibers for solid-phase microextraction have been prepared with a single bifunctional monomer, N,O-bismethacryloyl ethanolamine using the so-called "one monomer molecularly imprinted polymers" method, replacing the conventional combination of functional monomer and cross-linker to form high fidelity binding sites. For comparison, imprinted fibers were prepared following the conventional approach based on ethylene glycol dimethacrylate as cross-linker and methacrylic acid as monomer. The recognition performance of the new fibers was evaluated in the solid-phase microextraction of parabens, and from this study it was concluded that they provided superior performance over conventionally formulated fibers. Ultimately, real-world environmental testing on spiked solid samples was successful by the molecularly imprinted solid-phase microextraction of samples, and the relative recoveries obtained at enrichment levels of 10 ng/g of parabens were within 78-109% for soil and 83-109% for sediments with a relative standard deviation <15% (n = 3). PMID:26582435

  17. Molecularly imprinted sol-gel nanofibers based solid phase microextraction coupled on-line with high performance liquid chromatography for selective determination of acesulfame.

    PubMed

    Moein, Mohammad Mahdi; Javanbakht, Mehran; Karimi, Mohammad; Akbari-adergani, Behrouz

    2015-03-01

    Sol-gel based molecularly imprinted polymer (MIP) nanofiber was successfully fabricated by electrospinning technique on the surface of a stainless steel bar. The manufactured tool was applied for on-line selective solid phase microextraction (SPME) and determination of acesulfame (ACF) as an artificial sweetener with high performance liquid chromatography (HPLC). The selective ability of method for the extraction of ACF was investigated in the presence of some selected sweeteners such as saccharine (SCH), aspartame (ASP) and caffeine (CAF). Electrospinning of MIP sol-gel solution on the stainless steel bar provided an unbreakable sorbent with high thermal, mechanical, and chemical stability. Moreover, application of the MIP-SPME tool revealed a unique approach for the selective microextraction of the analyte in beverage samples. In this work, 3-(triethoxysilyl)-propylamine (TMSPA) was chosen as a precursor due to its ability to imprint the analyte by hydrogen bonding, Van der Walls, and dipole-dipole interactions. Nylon 6 was also added as a backbone and support for the precursor in which sol could greatly growth during the sol-gel process and makes the solution electrospinable. Various effective parameters in the extraction efficiency of the MIP-SPME tool such as loading time, flow rate, desorption time, selectivity, and the sample volume were evaluated. The linearity for the ACF in beverage sample was in the range of 0.78-100.5 ng mL(-1). Limit of detection (LOD) and quantification (LOQ) were 0.23 and 0.78 ng mL(-1) respectively. The RSD values (n=5) were all below 3.5%at the 20 ng mL(-1) level. PMID:25618677

  18. Use of Solid Phase Extraction in the Biochemistry Laboratory to Separate Different Lipids

    ERIC Educational Resources Information Center

    Flurkey, William H.

    2005-01-01

    Solid-phase extraction (SPE) was used to demonstrate how various lipids and lipid classes could be separated in a biochemistry laboratory setting. Three different SPE methods were chosen on their ability to separate a lipid mixture, consisting of a combination of a either a fatty acid, a triacylglycerol, a mono- or diacylglycerol, phospholipid,…

  19. COMPARISON OF TWO DIFFERENT SOLID PHASE EXTRACTION/LARGE VOLUME INJECTION PROCEDURES FOR METHOD 8270

    EPA Science Inventory

    Two solid phase (SPE) and one traditional continuous liquid-liquid extraction method are compared for analysis of Method 8270 SVOCs. Productivity parameters include data quality, sample volume, analysis time and solvent waste.

    One SPE system, unique in the U.S., uses aut...

  20. AUTOMATED SOLID PHASE EXTRACTION GC/MS FOR ANALYSIS OF SEMIVOLATILES IN WATER AND SEDIMENTS

    EPA Science Inventory

    Data is presented on the development of a new automated system combining solid phase extraction (SPE) with GC/MS spectrometry for the single-run analysis of water samples containing a broad range of organic compounds. The system uses commercially available automated in-line sampl...

  1. Development of a Solid Phase Extraction Method for Agricultural Pesticides in Large-Volume Water Samples

    EPA Science Inventory

    An analytical method using solid phase extraction (SPE) and analysis by gas chromatography/mass spectrometry (GC/MS) was developed for the trace determination of a variety of agricultural pesticides and selected transformation products in large-volume high-elevation lake water sa...

  2. Ethanol/Water extraction combined with solid-phase extraction and solid-phase microextraction concentration for the determination of chlorophenols in cork stoppers.

    PubMed

    Insa, Sara; Besalú, Emili; Iglesias, Cristina; Salvadó, Victoria; Anticó, Enriqueta

    2006-02-01

    The appearance of 2,4,6-trichloroanisole (TCA) in cork stoppers is of great concern because it can cause off-flavors in bottled wine. To prevent this sensorial defect, there should not be any traces of 2,4,6-trichlorophenol (TCP), 2,3,4,6-tetrachlorophenol (TeCP), or pentachlorophenol (PCP) in the finished corks, because they are the direct precursors of TCA. In the course of this study two methodologies based upon an extraction with ethanol/water mixtures to determine the chlorophenolic content in cork matrices were developed. The cork extract is preconcentrated using both solid-phase extraction and solid-phase microextraction methodologies. The latter was optimized by applying a full two-level factorial design. Finally, spiked ground corks at nanogram per gram levels of each chlorophenol were analyzed under optimal conditions and by applying both procedures. The obtained results demonstrate that chlorophenols can be detected in corks contaminated at the nanogram per gram level and, thus, these approaches can be successfully applied as quality control measures in the cork industry. PMID:16448159

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

    PubMed

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

    2015-09-01

    Non-polar solvent dynamic microwave assisted extraction was firstly applied to the treatment of high-fat soybean samples. In the dispersive micro-solid-phase extraction (D-µ-SPE), the herbicides in the high-fat extract were directly adsorbed on metal-organic frameworks MIL-101(Cr). The effects of several experimental parameters, including extraction solvent, microwave absorption medium, microwave power, volume and flow rate of extraction solvent, amount of MIL-101(Cr), and D-µ-SPE time, were investigated. At the optimal conditions, the limits of detection for the herbicides ranged from 1.56 to 2.00 μg kg(-1). The relative recoveries of the herbicides were in the range of 91.1-106.7%, and relative standard deviations were equal to or lower than 6.7%. The present method was simple, rapid and effective. A large amount of fat was also removed. This method was demonstrated to be suitable for treatment of high-fat samples. PMID:26003690

  4. Molecularly Imprinted Polymers for Ochratoxin A Extraction and Analysis

    PubMed Central

    Yu, Jorn C. C.; Lai, Edward P. C.

    2010-01-01

    Molecularly imprinted polymers (MIPs) are considered as polymeric materials that mimic the functionality of antibodies. MIPs have been utilized for a wide variety of applications in chromatography, solid phase extraction, immunoassays, and sensor recognition. In this article, recent advances of MIPs for the extraction and analysis of ochratoxins are discussed. Selection of functional monomers to bind ochratoxin A (OTA) with high affinities, optimization of extraction procedures, and limitations of MIPs are compared from different reports. The most relevant examples in the literature are described to clearly show how useful these materials are. Strategies on MIP preparation and schemes of analytical methods are also reviewed in order to suggest the next step that would make better use of MIPs in the field of ochratoxin research. The review ends by outlining the remaining issues and impediments. PMID:22069649

  5. Molecularly imprinted polymer cartridges coupled to liquid chromatography for simple and selective analysis of penicilloic acid and penilloic acid in milk by matrix solid-phase dispersion.

    PubMed

    Luo, Zhimin; Du, Wei; Zheng, Penglei; Guo, Pengqi; Wu, Ningli; Tang, Weili; Zeng, Aiguo; Chang, Chun; Fu, Qiang

    2015-09-01

    A simple, fast and sensitive method for determination of the degradation products of penicillin (penicilloic acid and penilloic acid) in milk samples has been developed by combining selective surface molecularly imprinted matrix solid-phase dispersion and high performance liquid chromatography (SMIPs-MSPD-HPLC). The selected dispersant SMIPs had high affinity for penicilloic acid and penilloic acid in milk matrix and the obtained extract was sufficiently clean for direct injection for HPLC analysis without any interference from the matrix. The proposed SMIPs-MSPD-HPLC method was validated for linearity, precision, accuracy, limit of detection and limit of quantitation. Linearity ranged from 0.04 to 4 μg g(-1) (correlation coefficient r(2) > 0.999). Recoveries of penicilloic acid from milk samples at different spiked levels were between 79.8 and 90.3%, with RSD values within 5.2-7.4%, and the limit of detection and limit of quantitation values were 0.04 and 0.13 μg g(-1), respectively. Recoveries of penilloic acid from milk samples at different spiked levels were between 77.4 and 86.2%, with RSD values within 3.1-6.4%, and the limit of detection and limit of quantitation values were 0.05 and 0.17 μg g(-1), respectively. The developed SMIPs-MSPD-HPLC method was successfully applied to direct determination of penicilloic acid and penilloic acid in milk samples. PMID:26028582

  6. Semiautomated solid-phase extraction manifold with a solvent-level sensor.

    PubMed

    Orlando, R M; Rath, S; Rohwedder, J J R

    2013-11-15

    A semiautomated solid-phase extraction manifold for multiple extractions is presented. The manifold utilizes commercial solid-phase syringe cartridges and automatically introduces and elutes all the solvents during the extraction, reducing the typical workload and stress of the analyst. The manifold consists of a peristaltic pump with solenoid valves in a flow circuit that contains transmissive photomicrosensors. The photomicrosensors were used to control the solvent dispenser and the solvent level inside the cartridge. As solvent-level sensors, the photomicrosensors determined the exact time the solvent reached the top frit to avoid sorbent drying and accurately perform the solvent exchange. The repeatability of the manifold to introduce a particular volume of solvent into the cartridges was measured, and the precisions were between 0.05 and 2.89% (RSD). To evaluate the manifold, the amount of two fluoroquinolones in a fortified blank milk sample was determined. The results of the intra- and inter-day precision of multiple extractions from the fortified milk samples resulted in precisions better than 9.0% (RSD) and confirmed that the arrangement of the semiautomated manifold could adequately be used in solid-phase extraction with commercial cartridges. PMID:24148370

  7. Soxhlet-assisted matrix solid phase dispersion to extract flavonoids from rape (Brassica campestris) bee pollen.

    PubMed

    Ma, Shuangqin; Tu, Xijuan; Dong, Jiangtao; Long, Peng; Yang, Wenchao; Miao, Xiaoqing; Chen, Wenbin; Wu, Zhenhong

    2015-11-15

    Soxhlet-assisted matrix solid phase dispersion (SA-MSPD) method was developed to extract flavonoids from rape (Brassica campestris) bee pollen. Extraction parameters including the extraction solvent, the extraction time, and the solid support conditions were investigated and optimized. The best extraction yields were obtained using ethanol as the extraction solvent, silica gel as the solid support with 1:2 samples to solid support ratio, and the extraction time of one hour. Comparing with the conventional solvent extraction and Soxhlet method, our results show that SA-MSPD method is a more effective technique with clean-up ability. In the test of six different samples of rape bee pollen, the extracted content of flavonoids was close to 10mg/g. The present work provided a simple and effective method for extracting flavonoids from rape bee pollen, and it could be applied in the studies of other kinds of bee pollen. PMID:26454344

  8. Quantitation of Binding, Recovery and Desalting Efficiency in Solid Phase Extraction Micropipette Tips

    SciTech Connect

    Palmblad, M N; Vogel, J S

    2004-08-02

    Micropipette-tip solid phase extraction systems are common in proteomic analyses for desalting and concentrating samples for mass spectrometry, removing interferences, and increasing sensitivity. These systems are inexpensive, disposable, and highly efficient. Here we show micropipette-tip solid phase extraction is a direct sample preparation method for {sup 14}C-accelerator mass spectrometry (AMS), removing salts or reagent from labeled macromolecules. We compared loading, recovery and desalting efficiency in commercially available SPE micro-tips using {sup 14}C-labeled peptides and proteins, AMS, and alpha spectrometry ion energy loss quantitation. The polypropylene in the tips was nearly {sup 14}C-free and simultaneously provided low-background carrier for AMS. The silica material did not interfere with the analysis. Alpha spectrometry provided an absolute measurement of desalting efficiency.

  9. Cost-effective imprinting combining macromolecular crowding and a dummy template for the fast purification of punicalagin from pomegranate husk extract.

    PubMed

    Sun, Guang-Ying; Wang, Chao; Luo, Yu-Qin; Zhao, Yong-Xin; Yang, Jian; Liu, Zhao-Sheng; Aisa, Haji Akber

    2016-05-01

    The combination of molecular crowding and virtual imprinting was employed to develop a cost-effective method to prepare molecularly imprinted polymers. By using linear polymer polystyrene as a macromolecular crowding agent, an imprinted polymer recognizable to punicalagin had been successfully synthesized with punicalin as the dummy template. The resulting punicalin-imprinted polymer presented a remarkable selectivity to punicalagin with an imprinting factor of 3.17 even at extremely low consumption of the template (template/monomer ratio of 1:782). In contrast, the imprinted polymer synthesized without crowding agent, did not show any imprinting effect at so low template amount. The imprinted polymers made by combination of molecular crowding and virtual imprinting can be utilized for the fast separation of punicalagin from pomegranate husk extract after optimizing the protocol of solid-phase extraction with the recovery of 85.3 ± 1.2%. PMID:27027975

  10. Extraction of phenolic compounds from water samples by dispersive micro-solid-phase extraction.

    PubMed

    Babaee, Shirin; Daneshfar, Ali

    2016-07-01

    In this article, the use of magnetically separable sorbent polyaniline/silica-coated nickel nanoparticles is evaluated under a dispersive micro-solid-phase extraction approach for the extraction of phenolic compounds from water samples. The sorbent was prepared by in situ chemical polymerization of aniline on the surface of silica-modified nickel nanoparticles and was characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray powder diffraction, scanning electron microscopy, energy-dispersive X-ray spectrometry, and vibrating sample magnetometry. Effective variables such as amount of sorbent (milligrams), pH and ionic strength of sample solution, volume of eluent solvent (microliters), vortex, and ultrasonic times (minutes) were investigated by fractional factorial design. The significant variables optimized by a Box-Behnken design were combined by a desirability function. Under the optimized conditions, the calibration graphs of analytes were linear in a concentration range of 0.02-100 μg/mL, and with correlation coefficients more than 0.999. The limits of detection and quantification were in the ranges of 10-23 and 33-77 μg/L, respectively. This procedure was successfully employed in the determination of target analytes in spiked water samples; the relative mean recoveries ranged from 96 to 105%. PMID:27136047

  11. Synthesis and evaluation of silver nanoparticles material for solid phase extraction of cobalt from water samples

    NASA Astrophysics Data System (ADS)

    Khajeh, Mostafa; Sanchooli, Esmael

    2011-12-01

    In this study, a new solid phase extractor, nano-scale silver particles were synthesized. The silver nanoparticle-based solid phase extraction was used for separation and preconcentration of the trace amount of cobalt ion from various water samples prior to its determination by flame atomic absorption spectrometry. The effects of various parameters, including pH, amount of complexing agent [1-(2-pyridylazo)-2-naphthol] (PAN), flow rates of solution and eluent, type and least amount of the eluent for elution of the cobalt from silver nanoparticles were studied and optimized. Under the optimum conditions, the detection limit of this procedure was 0.78 μg L-1, and the relative standard deviation (RSD%) was 3.1% ( n = 10, c = 20 μg L-1). This method was applied to the determination of cobalt in water samples.

  12. [Selective enrichment of iridoid glucosides in Hedyotis diffusa Willd. by tandem solid phase extraction].

    PubMed

    Zhang, Feng; Guo, Zhimou; Zhang, Feifang; Xue, Xingya; Liang, Xinmiao

    2009-07-01

    A method for selective enrichment of iridoid glucosides in Hedyotis diffusa Willd. by tandem solid phase extraction (SPE) was developed. Oligo(ethylene glycol) (OEG) is a novel type of separation material made in this laboratory. The differences of the surface chemical structures between OEG material and ODS material resulted in their different retention capabilities for iridoid glucosides. Based on the differences, an OEG-ODS solid phase extraction method was designed for selective enrichment of iridoid glucosides. The water extract (150.28 mg) of Hedyotis diffusa Willd. was precipitated by ethanol, and an aliquot (27.03 mg) of the product from the supernatant solution was loaded onto an OEG cartridge and rinsed by 5 mL water. Then, the rinsing solution was loaded onto an ODS cartridge. After it was washed by 5 mL water and eluted by 5 mL methanol, 4.01 mg final product was obtained from the methanol eluent. All the products were characterized by ultra performance liquid chromatography (UPLC), and 14 representative peaks of iridoid glucosides were found. The enrichment results were proved effective by directly comparing the chromatograms each step. To further characterize the enrichment efficiency, the changes of the peak area of iridoid glucosides were investigated. The results showed that the content of 14 iridoid glucosides in the final product reached 6.10 times its original proportion in water extraction product and their recovery was 50.1% on average. Therefore, the iridoid glucosides can be enriched by the tandem solid phase extraction method from water extracting-ethanol precipitating solution of Hedyotis diffusa Willd. with a good selectivity and an acceptable recovery. The proposed method has the advantages of high enrichment efficiency and simple operation. PMID:19938499

  13. LC determination of Z-338, novel gastroprokinetic agent in dog plasma by SCX solid phase extraction.

    PubMed

    Furuta, S; Miyahara, H; Sugimoto, T; Sano, H

    2001-06-01

    A simple high-performance liquid chromatographic assay with using UV detection (266 nm) was developed to determine a novel gastroprokinetic agent, Z-338 in dog plasma. The extraction procedure using solid-phase extraction with a Isolute SCX column produces extremely clean eluates and a high recovery. Intra- and inter-day variabilities were lower than 5%. The limit of quantitation of the method was 2.5 ng/ml. This assay was applied to the monitoring of Z-338 concentrations in dogs after oral administration. The method also appeared rapid, simple and suitable for therapeutic Z-338 monitoring. PMID:11377040

  14. Solid-phase extraction and HPLC analysis of kebuzone and its metabolites in blood.

    PubMed

    Klimes, J; Sochor, J; Sedlacek, J

    1996-09-01

    A HPLC method for quantification of kebuzone and its metabolites in whole blood was developed. The compounds and the internal standard were isolated from blood by solid-phase extraction on a C-18 cartridge. A blood sample was to be hemolyzed before extraction. HPLC was performed on a C-18 column with the mobile phase composed of methanol/water acidified to pH 2.7 and UV absorbance detection at 247 nm. This method has been successfully applied to a pharmacokinetic study of kebuzone and its metabolites in rabbits. PMID:8878255

  15. Analysis of ecologically relevant pharmaceuticals in wastewater and surface water using selective solid phase extraction and UPLC/MS/MS

    EPA Science Inventory

    A rapid and sensitive method has been developed for the analysis of 48 human prescription active pharmaceutical ingredients (APIs) and 6 metabolites of interest, utilizing selective solid-phase extraction (SPE) and ultra performance liquid chromatography in combination with tripl...

  16. Solid-phase purification and extraction for the determination of trace neonicotinoid pesticides in tea infusion.

    PubMed

    Zhang, Minglu; Chen, Hongping; Zhu, Li; Wang, Chuanpi; Ma, Guicen; Liu, Xin

    2016-03-01

    An analytical protocol that includes solid-phase purification and extraction is successfully developed for the determination of trace neonicotinoid pesticides in tea infusion. The method consists of a purification on amino-functionalized mesoporous silica SBA-15 followed by a solid-phase extraction based on graphene oxide before ultra high performance liquid chromatography with tandem mass spectrometry analysis. Parameters that significantly affected the extraction of the neonicotinoids onto graphene oxide, such as the amount of adsorbent, extraction time, pH, elution solvent, etc. were optimized. The amino-functionalized mesoporous silica SBA-15 has been proved to be an efficient adsorbent for removal of polyphenols especially catechins from tea infusion. Graphene oxide exhibits a very rapid adsorption rate (within 10 min) and high adsorption capacities for neonicotinoids at low initial concentration (0.01-0.5 mg/L). The analysis method gave a good determination coefficient (r(2) > 0.99) for each pesticide and high recoveries in the range of 72.2-95.0%. Powder X-ray diffraction, Raman spectroscopy, transmission electron microscopy, and UV-vis spectroscopy were utilized to identify the structure and morphology of graphene oxide. The adsorption driving force of neonicotinoids on graphene oxide mainly depends on π-π electron donor-acceptor interaction and electrostatic interaction. PMID:26639124

  17. Solid phase extraction and metabolic profiling of exudates from living copepods

    PubMed Central

    Heuschele, Jan; Nylund, Göran M.; Pohnert, Georg; Pavia, Henrik; Bjærke, Oda; Pender-Healy, Larisa A.; Tiselius, Peter; Kiørboe, Thomas

    2016-01-01

    Copepods are ubiquitous in aquatic habitats. They exude bioactive compounds that mediate mate finding or induce defensive traits in prey organisms. However, little is known about the chemical nature of the copepod exometabolome that contributes to the chemical landscape in pelagic habitats. Here we describe the development of a closed loop solid phase extraction setup that allows for extraction of exuded metabolites from live copepods. We captured exudates from male and female Temora longicornis and analyzed the content with high resolution LC-MS. Chemometric methods revealed 87 compounds that constitute a specific chemical pattern either qualitatively or quantitatively indicating copepod presence. The majority of the compounds were present in both female and male exudates, but nine compounds were mainly or exclusively present in female exudates and hence potential pheromone candidates. Copepodamide G, known to induce defensive responses in phytoplankton, was among the ten compounds of highest relative abundance in both male and female extracts. The presence of copepodamide G shows that the method can be used to capture and analyze chemical signals from living source organisms. We conclude that solid phase extraction in combination with metabolic profiling of exudates is a useful tool to develop our understanding of the chemical interplay between pelagic organisms. PMID:26788422

  18. Solid phase extraction and HPLC analysis of toxic components eluted from methyl methacrylate dental materials.

    PubMed

    Shintani, H; Tsuchiya, T; Hata, Y; Nakamura, A

    1993-01-01

    Methyl methacrylate polymer (PolyMMA) is widely used as the composite resin for the dental plate. During the fabrication process of PolyMMA for the polymerization reaction, benzoylperoxide (BPO) and N,N-dimethyl p-toluidine (DMPT) are added as the initiator and the stimulator, respectively. Because these compounds exhibit toxicity as well as a residue potential, their use raises concerns regarding human safety. The degree of dissolution into serum was determined to evaluate risk to the user. Analysis was by HPLC combined with solid-phase extraction using a C-18 column. The eluted compounds were found to be in the order of 10 to 100 ppm. PMID:8492570

  19. Application of solid phase extraction procedures for rare earth elements determination in environmental samples.

    PubMed

    Pyrzynska, Krystyna; Kubiak, Anna; Wysocka, Irena

    2016-07-01

    Determination of rare earth elements in environmental samples requires often pre-concentration and separation step due to a low metal content and high concentration of the interfering matrix components. A solid phase extraction technique with different kind of solid sorbents offers a high enrichment factor, rapid phase separation and the possibility of its combination with various detection techniques used either in on-line or off-line mode. The recent developments in this area published over the last five years are presented and discussed in this paper. PMID:27154643

  20. Automated solid-phase extraction of herbicides from water for gas chromatographic-mass spectrometric analysis

    USGS Publications Warehouse

    Meyer, M.T.; Mills, M.S.; Thurman, E.M.

    1993-01-01

    An automated solid-phase extraction (SPE) method was developed for the pre-concentration of chloroacetanilide and triazine herbicides, and two triazine metabolites from 100-ml water samples. Breakthrough experiments for the C18 SPE cartridge show that the two triazine metabolites are not fully retained and that increasing flow-rate decreases their retention. Standard curve r2 values of 0.998-1.000 for each compound were consistently obtained and a quantitation level of 0.05 ??g/l was achieved for each compound tested. More than 10,000 surface and ground water samples have been analyzed by this method.

  1. Novel nanoporous sorbent for solid-phase extraction in petroleum fingerprinting

    NASA Astrophysics Data System (ADS)

    Alayande, S. Oluwagbemiga; Hlengilizwe, Nyoni; Dare, E. Olugbenga; Msagati, Titus A. M.; Akinlabi, A. Kehinde; Aiyedun, P. O.

    2016-04-01

    Sample preparation is crucial in the analysis of petroleum and its derivatives. In this study, developing affordable sorbent for petroleum fingerprinting analysis using polymer waste such expanded polystyrene was explored. The potential of electrospun expanded polystyrene (EPS) as a sorbent for the solid-phase extraction (SPE) technique was investigated, and its efficiency was compared with commercial cartridges such as alumina, silica and alumina/silica hybrid commercial for petroleum fingerprinting analysis. The chromatograms showed that the packed electrospun EPS fibre demonstrated excellent properties for SPE applications relative to the hybrid cartridges.

  2. Isolation and analysis of sugar nucleotides using solid phase extraction and fluorophore assisted carbohydrate electrophoresis.

    PubMed

    Barnes, Jarrod; Tian, Liping; Loftis, Jacqueline; Hiznay, James; Comhair, Suzy; Lauer, Mark; Dweik, Raed

    2016-01-01

    The building blocks of simple and complex oligosaccharides, termed sugar nucleotides, are often overlooked for their role in metabolic diseases and may hold the key to the underlying disease pathogenesis. Multiple reasons may account for the lack of analysis and quantitation of these sugar nucleotides, including the difficulty in isolation and purification as well as the required expensive instrumentation such as a high performance liquid chromatography (HPLC), mass spectrometer, or capillary electrophoresis. We have established a simple yet effective way to purify and quantitate sugar nucleotides using solid phase extraction (SPE) chromatography combined with fluorophore assisted carbohydrate electrophoresis (FACE). The simplicity of use, combined with the ability to run multiple samples at one time, give this technique a distinct advantage over the established methods for isolation and analysis of sugar nucleotides from cell culture models. •Sugar nucleotides can be easily purified with solid phase extraction chromatography.•FACE can be used to analyze multiple nucleotide sugar extracts with a single run.•The proposed method is simple, affordable, and uses common everyday research labware. PMID:27222820

  3. Isolation and analysis of sugar nucleotides using solid phase extraction and fluorophore assisted carbohydrate electrophoresis

    PubMed Central

    Barnes, Jarrod; Tian, Liping; Loftis, Jacqueline; Hiznay, James; Comhair, Suzy; Lauer, Mark; Dweik, Raed

    2016-01-01

    The building blocks of simple and complex oligosaccharides, termed sugar nucleotides, are often overlooked for their role in metabolic diseases and may hold the key to the underlying disease pathogenesis. Multiple reasons may account for the lack of analysis and quantitation of these sugar nucleotides, including the difficulty in isolation and purification as well as the required expensive instrumentation such as a high performance liquid chromatography (HPLC), mass spectrometer, or capillary electrophoresis. We have established a simple yet effective way to purify and quantitate sugar nucleotides using solid phase extraction (SPE) chromatography combined with fluorophore assisted carbohydrate electrophoresis (FACE). The simplicity of use, combined with the ability to run multiple samples at one time, give this technique a distinct advantage over the established methods for isolation and analysis of sugar nucleotides from cell culture models. • Sugar nucleotides can be easily purified with solid phase extraction chromatography. • FACE can be used to analyze multiple nucleotide sugar extracts with a single run. • The proposed method is simple, affordable, and uses common everyday research labware. PMID:27222820

  4. Halogen bonding: a new retention mechanism for the solid phase extraction of perfluorinated iodoalkanes.

    PubMed

    Yan, Xiao Qing; Shen, Qian Jin; Zhao, Xiao Ran; Gao, Hai Yue; Pang, Xue; Jin, Wei Jun

    2012-11-13

    For the first time, halogen-bonding interaction is utilised in the solid phase extraction of perfluorinated iodoalkane (PFI). Nine PFIs, as model analytes, were tested, and analyses by UV, (19)F NMR and Raman spectroscopies demonstrate that the PFIs are extracted by a strong anion exchange (SAX) sorbent from n-hexane due to the C-I···Cl(-) halogen-bonding interactions. The results also show that the adsorptivities of SAX for the diiodoperfluoro-alkanes (diiodo-PFIs) were much stronger than those for the perfluoroalkyl iodides (monoiodo-PFIs). Specifically, the recoveries for 1,6-diiodoperfluorohexane and 1,8-diiodoperfluorooctane were higher than 80% when 100mL of sample spiked with a 5 ng mL(-1) analyte mixture was extracted. Interestingly, SAX had no adsorption for hexafluorobenzene at all, which is known to be unable to form a halogen bond with Cl(-). The analytical performance of the halogen bond-based SPE-GC-MS method for the diiodo-PFIs was also examined in soil samples. The sorbent SAX enabled the selective extraction of four diiodo-PFIs successfully from soil samples. The recoveries of the diiodo-PFIs extracted from 5 g soil sample at the 100 ng g(-1) spike level were in the range of 73.2-93.8% except 26.8% for 1,2-diiodoperfluoroethane. The limit of detection varied from 0.02 to 0.04 ng g(-1) in soil samples. Overall, this work reveals the great application potential of halogen bonding in the field of solid phase extraction to selectively extract compounds with strong halogen-bonding abilities. PMID:23107136

  5. Determination of triazine herbicides in seaweeds: development of a sample preparation method based on Matrix Solid Phase Dispersion and Solid Phase Extraction Clean-up.

    PubMed

    Rodríguez-González, N; González-Castro, M J; Beceiro-González, E; Muniategui-Lorenzo, S; Prada-Rodríguez, D

    2014-04-01

    A method using dual process columns of Matrix Solid Phase Dispersion (MSPD) and Solid Phase Extraction (SPE) has been developed for extracting and cleaning-up of nine triazine herbicides (ametryn, atrazine, cyanazine, prometryn, propazine, simazine, simetryn, terbuthylazine and terbutryn) in seaweed samples. Under optimized conditions, samples were blended with 2g of octasilyl-derivatized silica (C8) and transferred into an SPE cartridge containing ENVI-Carb II/PSA (0.5/0.5 g) as a clean up co-sorbent. Then the dispersed sample was washed with 10 mL of n-hexane and triazines were eluted with 20 mL ethyl acetate and 5 mL acetonitrile. Finally the extract was concentrated to dryness, re-constituted with 1 mL methanol:water (1:1) and injected into the HPLC-DAD system. The linearity of the calibration curves was excellent in matrix matched standards, and yielded the coefficients of determination>0.995 for all the target analytes. The recoveries ranged from 75% to 100% with relative standard deviations lower than 7%. The achieved LOQs (<10 µg kg(-1)) for all triazines under study permits to ensure proper determination at the maximum allowed residue levels set in the European Union Legislation. Samples of three seaweeds were subjected to the procedure proving the suitability of MSPD method for the analysis of triazines in different seaweeds samples. PMID:24607126

  6. Determination of available phenolic compounds in soils by liquid chromatography with solid-phase extraction.

    PubMed

    Matejícek, David; Klejdus, Borivoj; Kubán, Vlastimil

    2002-01-01

    A fast, selective, and sensitive liquid chromatographic (LC) method was developed for determination of derivatives of benzoic and cinnamic acids (gallic, protocatechuic, 2,3,4-trihydroxybenzoic, 4-hydroxybenzoic, vanillic, caffeic, syringic, 4-coumaric, ferulic, sinapic, benzoic, 2-coumaric, cinnamic acids, and 4-hydroxybenzaldehyde and vanillin) in soil samples. The method for sample pretreatment is based on temperature-controlled extraction with water (pH 5.6) for 60 min. Extracts were preconcentrated and purified by solid-phase extraction on OASIS HLB sorbent, with subsequent separation and quantification of individual substances by LC with UV diode-array detection. Limits of detection (3 signal-to-noise LODs) better than 65 ng/g (dry weight) and recoveries from 88 to 99% were found for each compound at absorbance 280 nm. The method was used for determination of bioavailable phenolic compounds in different soil samples. PMID:12477182

  7. Rapid determination of ions by combined solid-phase extraction--diffuse reflectance spectroscopy

    NASA Technical Reports Server (NTRS)

    Fritz, James S.; Arena, Matteo P.; Steiner, Steven A.; Porter, Marc D.

    2003-01-01

    We introduce colorimetric solid-phase extraction (C-SPE) for the rapid determination of selected ions. This new technique links the exhaustive concentration of an analyte by SPE onto a membrane disk surface for quantitative measurement with a hand-held diffuse reflectance spectrometer. The concentration/measurement procedure is complete in approximately 1 min and can be performed almost anywhere. This method has been used to monitor iodine and iodide in spacecraft water in the 0.1-5.0 ppm range and silver(I) in the range of 5.0-1000 microg/l. Applications to the trace analysis of copper(II), nickel(II), iron(III) and chromium(VI) are described. Studies on the mechanism of extraction showed that impregnation of the disk with a surfactant as well as a complexing reagent results in uptake of additional water, which markedly improves the extraction efficiency.

  8. Solid-phase extraction and GC/MS confirmation of barbiturates from human urine.

    PubMed

    Pocci, R; Dixit, V; Dixit, V M

    1992-01-01

    A highly selective and sensitive procedure has been developed for isolating and identifying barbiturates in human urine. With a new disposable bonded silica gel solid-phase extraction (SPE) column and hexobarbital as an internal standard (IS), amobarbital, butabarbital, pentobarbital, phenobarbital, secobarbital, and methaqualone were selectively isolated from endogenous urine components. Capillary gas chromatography/ion trap mass spectrometry (GC/MS) analysis of the extracts generated a full mass spectrum for the detection, identification, and quantitation of barbiturates. Linear quantitative response curves for the drugs have been generated over a concentration range of 20-500 ng/mL. Overall extraction efficiencies for drugs averaged greater than 90%, and the quantitative response curves exhibited correlation coefficients of 0.996 to 0.999. PMID:1353548

  9. Comparison of solvent extraction and solid-phase extraction for the determination of polychlorinated biphenyls in transformer oil.

    PubMed

    Mahindrakar, A N; Chandra, S; Shinde, L P

    2014-01-01

    Solid-phase extraction (SPE) of nine polychlorinated biphenyls (PCBs) from transformer oil samples was evaluated using octadecyl (CI8)-bonded porous silica. The efficiency of SPE of these PCBs was compared with those obtained by solvent extraction with DMSO and hexane. Average recoveries exceeding 95% for these PCBs were obtained via the SPE method using small cartridges containing 100mg of 40 pm CI8-bonded porous silica. The average recovery by solvent extraction with DMSO and hexane exceeded 83%. It was concluded that the recoveries and precision for the solvent extraction of PCBs were poorer than those for the SPE. PMID:24083901

  10. Selective extraction and determination of chlorogenic acid in fruit juices using hydrophilic magnetic imprinted nanoparticles.

    PubMed

    Hao, Yi; Gao, Ruixia; Liu, Dechun; He, Gaiyan; Tang, Yuhai; Guo, Zengjun

    2016-06-01

    In this paper, the novel hydrophilic magnetic molecularly imprinted nanoparticles were developed for selective separation and determination of chlorogenic acid in aqueous fruit juices. The polymers were prepared by using amino-functionalized magnetic nanoparticles as carriers, branched polyethyleneimine as functional monomer, and chlorogenic acid as template molecule. Branched polyethyleneimine with abundant active amino groups could react with template sufficiently, and its unique dendritic structure may amplify the number of the imprinted cavities. Meanwhile, it would improve the hydrophilicity of imprinted materials for attaining high extraction efficiency. The resulted polymers exhibit fast kinetics, high adsorption capacity, and favorable selectivity. In addition, the obtained nanoparticles were used as solid-phase extraction sorbents for selective isolation and determination of chlorogenic acid in peach, apple, and grape juices (0.92, 4.21, and 0.75 μg mL(-1), respectively). PMID:26830581

  11. Quantitative separation of aliphatic and aromatic hydrocarbons using silver ion--silica solid-phase extraction

    PubMed

    Bennett; Larter

    2000-03-01

    A solid-phase extraction (SPE) method employing silver nitrate impregnated silica has been developed and evaluated for the separation of defined aliphatic and aromatic hydrocarbons from crude oils. The versatility of the SPE method is demonstrated using a light crude oil from the North Sea and a heavy crude oil from Orcutt field (Monterey, California, U.S.A.). The coefficients of variation for a number of geochemical parameters measured on both aliphatic and aromatic hydrocarbons were excellent. The separation efficiency of SPE is demonstrated using quantification of monoaromatic steroid hydrocarbons which are notoriously difficult to efficiently sequester into the aromatic hydrocarbon fraction using traditional liquid chromatographic procedure. The selectivity and efficiency of the SPE technique is comparable with that of silica gel TLC. However, losses of volatile compounds such as naphthalene are limited during SPE since the sample remains in solvent. We conclude that solid-phase extraction affords rapid sample turnover suitable for processing large sample numbers with high reproducibility. PMID:10739209

  12. Solid phase extraction of petroleum carboxylic acids using a functionalized alumina as stationary phase.

    PubMed

    de Conto, Juliana Faccin; Nascimento, Juciara dos Santos; de Souza, Driele Maiara Borges; da Costa, Luiz Pereira; Egues, Silvia Maria da Silva; Freitas, Lisiane Dos Santos; Benvenutti, Edilson Valmir

    2012-04-01

    Petroleum essentially consists of a mixture of organic compounds, mainly containing carbon and hydrogen, and, in minor quantities, compounds with nitrogen, sulphur, and oxygen. Some of these compounds, such as naphthenic acids, can cause corrosion in pipes and equipment used in processing plants. Considering that the methods of separation or clean up the target compounds in low concentrations and in complex matrix use large amounts of solvents or stationary phases, is necessary to study new methodologies that consume smaller amounts of solvent and stationary phases to identify the acid components present in complex matrix, such as crude oil samples. The proposed study aimed to recover acid compounds using the solid phase extraction method, employing different types of commercial stationary ion exchange phases (SAX and NH(2)) and new phase alumina functionalized with 1,4-bis(n-propyl)diazoniabicyclo[2.2.2]octane chloride silsesquioxane (Dab-Al(2)O(3)), synthesized in this work. Carboxylic acids were used as standard mixture in the solid phase extraction for further calculation of recovery yield. Then, the real sample (petroleum) was fractionated into saturates, aromatics, resins, and asphaltenes, and the resin fraction of petroleum (B1) was eluted through stationary ion exchange phases. The stationary phase synthesized in this work showed an efficiency of ion exchange comparable to that of the commercial stationary phases. PMID:22589166

  13. Immobilized humic substances and immobilized aggregates of humic substances as sorbent for solid phase extraction.

    PubMed

    Erny, Guillaume L; Gonçalves, Bruna M; Esteves, Valdemar I

    2013-09-01

    In this work, humic substances (HS) immobilized, as a thin layer or as aggregates, on silica gel were tested as material for solid phase extraction. Some triazines (simazine, atrazine, therbutylazine, atrazine-desethyl-desisopropyl-2-hydroxy, ametryn and terbutryn), have been selected as test analytes due to their environmental importance and to span a large range of solubility and octanol/water partition coefficient (logP). The sorbent was obtained immobilizing a thin layer of HS via physisorption on a pre-coated silica gel with a cationic polymer (polybrene). While the sorbent could be used as it is, it was demonstrated that additional HS could be immobilized, via weak interactions, to form stable humic aggregates. However, while a higher quantity of HS could be immobilized, no significant differences were observed in the sorption parameters. This sorbent have been tested for solid phase extraction to concentrate triazines from aqueous matrixes. The sorbent demonstrated performances equivalent to commercial alternatives as a concentration factor between 50 and 200, depending on the type of triazines, was obtained. Moreover the low cost and the high flow rate of sample through the column allowed using high quantity of sorbent. The analytical procedure was tested with different matrixes including tap water, river water and estuarine water. PMID:23916952

  14. Selective enrichment of the degradation products of organophosphorus nerve agents by zirconia based solid-phase extraction.

    PubMed

    Kanaujia, Pankaj K; Pardasani, Deepak; Tak, Vijay; Purohit, Ajay K; Dubey, D K

    2011-09-23

    Selective extraction and enrichment of nerve agent degradation products has been achieved using zirconia based commercial solid-phase extraction cartridges. Target analytes were O-alkyl alkylphosphonic acids and alkylphosphonic acids, the environmental markers of nerve agents such as sarin, soman and VX. Critical extraction parameters such as modifier concentration, nature and volume of washing and eluting solvents were investigated. Amongst other anionic compounds, selectivity in extraction was observed for organophosphorus compounds. Recoveries of analytes were determined by GC-MS which ranged from 80% to 115%. Comparison of zirconia based solid-phase extraction method with anion-exchange solid-phase extraction revealed its selectivity towards phosphonic acids. The limits of detection (LOD) and limit of quantification (LOQ) with selected analytes were achieved down to 4.3 and 8.5 ng mL(-1), respectively, in selected ion monitoring mode. PMID:21862029

  15. [Preparation of a novel polymer monolith using atom transfer radical polymerization method for solid phase extraction].

    PubMed

    Shen, Ying; Qi, Li; Qiao, Juan; Mao, Lanqun; Chen, Yi

    2013-04-01

    In this study, a novel polymer monolith based solid phase extraction (SPE) material has been prepared by two-step atom transfer radical polymerization (ATRP) method. Firstly, employing ethylene glycol dimethacrylate (EDMA) as a cross-linker, a polymer monolith filled in a filter head has been in-situ prepared quickly under mild conditions. Then, the activators generated by electron transfer ATRP (ARGET ATRP) was used for the modification of poly(2-(dimethylamino)ethyl-methacrylate) (PDMAEMA) on the monolithic surface. Finally, this synthesized monolith for SPE was successfully applied in the extraction and enrichment of steroids. The results revealed that ATRP can be developed as a facile and effective method with mild reaction conditions for monolith construction and has the potential for preparing monolith in diverse devices. PMID:23898628

  16. Determination of tylosin in feeds by liquid chromatography with solid-phase extraction.

    PubMed

    Gramse, Matthew J; Jacobson, Paul E; Selkirk, James C

    2004-01-01

    A method was developed for the determination of tylosin in feeds. The method involves extraction of tylosin with methanol, concentration under a stream of nitrogen, and cleanup using Phenomenex C18 solid-phase extraction cartridge. Analyte separation and quantitation were achieved by gradient reversed-phase liquid chromatography and UV absorbance at 285 nm with a reference wavelength of 320 nm with column temperature of 45 degrees C. Average spike recoveries for samples prepared at 4 spiking levels (22.7, 181, 907, and 1000 g/ton) were 111.0, 94.9, 96.2, and 98.6%, respectively. The overall method precision at each of the 4 spiking levels was < or = 7.85% relative standard deviation. The limits of detection and quantitation (g/ton) were 2.16 and 7.20 g/ton, respectively. PMID:15164825

  17. Environmentally Friendly Method: Development and Application to Carbon Aerogel as Sorbent for Solid-Phase Extraction.

    PubMed

    Dong, Sheying; Huang, Guiqi; Su, Meiling; Huang, Tinglin

    2015-10-14

    We developed two simple, fast, and environmentally friendly methods using carbon aerogel (CA) and magnetic CA (mCA) materials as sorbents for micro-solid-phase extraction (μ-SPE) and magnetic solid-phase extraction (MSPE) techniques. The material performances such as adsorption isotherm, adsorption kinetics, and specific surface area were discussed by N2 adsorption-desorption isotherm measurements, ultraviolet and visible (UV-vis) spectrophotometry, scanning electron microscopy (SEM), and high resolution transmission electron microscopy (HR-TEM). The experimental results proved that the heterogeneities of CA and mCA were well modeled with the Freundlich isotherm model, and the sorption process well followed the pseudo-second-order rate equation. Moreover, plant growth regulators (PGRs) such as kinetin (6-KT), 6-benzylaminopurine (6-BA), 2,4-dichlorophenoxyacetic acid (2,4-D), and uniconazole (UN) in a reservoir raw water sample were selected as the evaluation of applicability for the proposed μ-SPE and MSPE techniques using high performance liquid chromatography (HPLC). The experimental conditions of two methods such as the amount of sorbent, extraction time, pH, salt concentration, and desorption conditions were studied. Under the optimized conditions, two extraction methods provided high recoveries (89-103%), low the limits of detection (LODs) (0.01-0.2 μg L(-1)), and satisfactory analytical features in terms of precision (relative standard deviation, RSD, 1.7-5.1%, n=3). This work demonstrates the feasibility and the potential of CA and mCA materials as sorbents for μ-SPE and MSPE techniques. Besides, it also could serve as a basis for future development of other functional CAs in pretreatment technology and make them valuable for analysis of pollutants in environmental applications. PMID:26389684

  18. Investigation of recovery of volatiles of Bidens tripartita L. using solid-phase extraction trap in supercritical fluid extraction.

    PubMed

    Kaškonienė, Vilma; Maruška, Audrius

    2015-01-01

    Recovery of Bidens tripartita L. volatiles using supercritical CO2 extraction with solid-phase trap was performed in this study. Three points were analyzed: the impact of rinse solvent (heptane, methanol or acetonitrile) for analytes desorption from the trap; the impact of the amount of plant material used for extraction; the release of volatiles from plant matrix using multiple extraction. α-Pinene, p-cymene, β-ocimene, and β-elemene were predominant in all extracts prepared in different ways. β-Ocimene was the main compound (40-46%) in all extracts despite of the solvent used. No significant difference between the amount of α-pinene observed using different trap desorption solvent, while heptane desorbed significantly higher amounts (12-31%) of other compounds. The composition of volatiles using different amount of sample showed both qualitative and quantitative differences. The study showed different extraction extent of the main compounds during the first and repeated extractions. PMID:25830954

  19. Molecularly imprinted polymer for specific extraction of hypericin from Hypericum perforatum L. herbal extract.

    PubMed

    Li, Zhaozhou; Qin, Cuili; Li, Daomin; Hou, Yuze; Li, Songbiao; Sun, Junjie

    2014-09-01

    The molecularly imprinted polymers (MIPs) were prepared by an oxidation-reduction polymerization system using a non-covalent molecularly imprinting strategy with hypericin as the template, acrylamide as the functional monomer and pentaerythritol triacrylate as the cross-linker in the porogen of acetone. The UV spectrum revealed that a cooperative hydrogen-bonding complex between hypericin and acrylamide might be formed at the ratio of 1:6 in the prepolymerized system. Two classes of the binding sites were produced in the resulting hypericin-imprinted polymer with the dissociation constants of 16.61μgL(-1) and 69.35μgL(-1), and the affinity binding sites of 456.53μgg(-1) and 603.06μgg(-1), respectively. The synthesized MIPs were characterized by scanning electron microscope, thermogravimetric and differential thermal analysis. High-performance liquid chromatography was used to investigate the adsorption and recognition properties of the MIPs. Selective binding of the template molecule was demonstrated in comparison to the analog pseudohypericin. After the Hypericum perforatum L. plant being air dried and finely ground, an extract was prepared by shaking the powder in a methanol-water solution (80:20, v/v), vacuum filtration though a Büchner funnel, liquid-liquid extraction with ethyl ether and ethyl acetate, and evaporating on a rotary evaporator until dry. With the sorbents of the optimized MIPs, a molecularly imprinted solid-phase extraction (MISPE) procedure was developed for enrichment and separation of hypericin from the Hypericum extract in the presence of interfering substances. The selective extraction of hypericin from herbal medicine was achieved with the recovery of 82.30%. The results showed that MISPE can be a useful tool for specific isolation and effective clean-up of target compounds from natural products. PMID:24946147

  20. Development of a Paper Spray Mass Spectrometry Cartridge with Integrated Solid Phase Extraction for Bioanalysis.

    PubMed

    Zhang, Chengsen; Manicke, Nicholas E

    2015-06-16

    A novel paper spray cartridge with an integrated solid phase extraction (SPE) column is described. The cartridge performs extraction and pre-concentration, as well as sample ionization by paper spray, from complex samples such as plasma. The cartridge allows for selective enrichment of target molecules from larger sample volumes and removal of the matrix, which significantly improved the signal intensity of target compounds in plasma samples by paper spray ionization. Detection limits, quantitative performance, recovery, ionization suppression, and the effects of sample volume were evaluated for five drugs: carbamazepine, atenolol, sulfamethazine, diazepam, and alprazolam. Compared with direct paper spray analysis of dried plasma spots, paper spray analysis using the integrated solid phase extraction improved the detection limits significantly by a factor of 14-70, depending on the drug. The improvement in detection limits was, in large part, due to the capability of analyzing larger sample volumes. In addition, ionization suppression was found to be lower and recovery was higher for paper spray with integrated SPE, as compared to direct paper spray analysis. By spiking an isotopically labeled internal standard into the plasma sample, a linear calibration curve for the drugs was obtained from the limit of detection (LOD) to 1 μg/mL, indicating that this method can be used for quantitative analysis. The paper spray cartridge with integrated SPE could prove valuable for analytes that ionize poorly, in applications where lower detection limits are required, or on portable mass spectrometers. The improved performance comes at the cost of requiring a more complex paper spray cartridge and requiring larger sample volumes than those used in typical direct paper spray ionization. PMID:26000893

  1. Improved resins and novel materials and methods for solid phase extraction and high performance liquid chromatography

    SciTech Connect

    Freeze, R.

    1997-10-08

    Solid-phase extraction (SPE) has grown to be one of the most widely used methods for isolation and preconcentration of a vast range of compounds from aqueous solutions. By modifying polymeric SPE resins with chelating functional groups, the selective uptake of metals was accomplished. The resin, along with adsorbed metals, was vaporized in the ICP and detection of the metals was then possible using either mass or emission spectroscopy. Drug analyses in biological fluids have received heightened attention as drug testing is on the increase both in sports and in the work environment. By using a direct-injection technique, biological fluids can be injected directly into the liquid chromatographic system with no pretreatment. A new surfactant, a sulfonated form of Brij-30 (Brij-S) is shown to prevent the uptake of serum proteins on commercial HPLC columns by forming a thin coating on the silica C18 surface. Excellent separations of eight or more drugs with a wide range of retention times were obtained. The separations had sharper peaks and lower retention times than similar separations performed with the surfactant sodium dodecylsulfate (SDS). Quantitative recovery of a number of drugs with limits of detection near 1 ppm with a 5 {micro}l injection volume were obtained. Finally, a method for solid-phase extraction in a syringe is introduced. The system greatly reduced the volume of solvent required to elute adsorbed analytes from the SPE bed while providing a semi-automated setup. SPE in a syringe consists of a very small bed of resin-loaded membrane packed into a GC or HPLC syringe. After extraction, elution was performed with just a few {micro}l of solvent. This small elution volume allowed injection of the eluent directly from the syringe into the chromatographic system, eliminating the handling problems associated with such small volumes.

  2. Development of a sensitive methodology for the analysis of chlorobenzenes in air by combination of solid-phase extraction and headspace solid-phase microextraction.

    PubMed

    Barro, Ruth; Ares, Sergio; Garcia-Jares, Carmen; Llompart, Maria; Cela, Rafael

    2004-08-01

    In this study, a combination of solid-phase extraction (SPE) and solid-phase microextraction (SPME) has been used to determine chlorobenzenes in air. Analytes were sampled by pumping a known volume of air through a porous polymer (Tenax TA). Then, the adsorbent was transferred into a glass vial and SPME was performed. The quantification was carried out using gas chromatography (GC)-electron-capture detection or GC-MS. Several SPME coatings (100 microm poly(dimethylsiloxane) (PDMS), 75 microm Carboxen (CAR)-PDMS, 65 microm PDMS-divinylbenzene (DVB), 65 microm PDMS-DVB and 85 microm polyacrylate (PA) were evaluated, obtaining the highest responses with Carbowax (CW)- PDMS for the most volatile chlorobenzenes, and with PDMS-DVB or CW-DVB fibers for the semivolatile compounds. To optimize some other factors that could affect the SPME step, a factorial design was used. Kinetic studies of the SPME process were also performed. Concerning the SPE step, breakthrough was studied, showing that 2.5 m3 of air could be processed without losses of the most volatile compounds. The performance of the method was evaluated. External calibration, which does not require the complete sampling process, demonstrated to be suitable, obtaining good linearity (R2 > 0.99) for all chlorobenzenes. Recovery studies were performed at two concentration levels (4 and 40 ng/m3), obtaining quantitative recoveries (>80%). Limits of detection at the sub ng/m3 were achieved for all the target compounds. PMID:15378894

  3. Development of solid-phase extraction and solid-phase microextraction methods for the determination of chlorophenols in cork macerate and wine samples.

    PubMed

    Insa, S; Salvadó, V; Anticó, E

    2004-08-20

    Tri-, tetra- and pentachlorophenol (TCP, TeCP and PCP) can be considered the precursors in the formation of corresponding chloroanisoles, known to be powerful odorants in corks and wine. Determining the presence of these chlorophenolic compounds in cork soaking solutions (ethanol/water mixtures, 12% (v/v) ethanol used for cork quality control testing), or in wine can be achieved by acetylation/gas chromatography electron-capture detection. In order to reach the required sensitivity, a previous preconcentration step is necessary. Solid-phase extraction (SPE) and headspace solid-phase microextraction (HS-SPME) have given good results for the preconcentration of TCP, TeCP and PCP in such matrices. The use of Oasis HLB cartridges gives acceptable recoveries for the three compounds when different volumes (50-250 mL) of cork macerate with concentrations ranging from 20 to 150 ng/L are processed. Preconcentration based on HS-SPME has also been optimised with a 100 microm polydimethylsiloxane fibre and in situ derivatization. The HS-SPME method allows chlorophenols in a cork soaking solution and in wine to be determined with a limit of detection of 1 ng/L for each compound (in cork macerate) and a repeatability of around 0.5%-5% (n=8) for a concentration level of 30 ng/L. PMID:15481456

  4. Separation of phenolic acids from natural plant extracts using molecularly imprinted anion-exchange polymer confined ionic liquids.

    PubMed

    Bi, Wentao; Tian, Minglei; Row, Kyung Ho

    2012-04-01

    Polymer-confined ionic liquids were used for the separation of phenolic acids from natural plant extract by utilizing an anion-exchange mechanism. They were synthesized using molecular imprinting technique to reduce non-directional ion-ion interactions during anion-exchange and other interactions with interference substances that could decrease selectivity. A suitable sorbent for phenolic acid separation could be identified based on the adsorption behaviors of phenolic acids on different polymer-confined ionic liquids. Thus, the developed ionic liquid-based molecularly imprinted anion-exchange polymer (IMAP) achieved high recovery rates by solid-phase extraction of phenolic acids from Salicornia herbacea L. extract: 90.1% for protocatechuic acid, 95.5% for ferulic acid and 96.6% for caffeic acid. Moreover, the phenolic acids were separable from each other by repeated solid phase extraction cycles. The proposed method could be used to separate other phenolic acids or organic acids from complex samples. PMID:21903215

  5. Ion-exchange molecularly imprinted polymer for the extraction of negatively charged acesulfame from wastewater samples.

    PubMed

    Zarejousheghani, Mashaalah; Schrader, Steffi; Möder, Monika; Lorenz, Pierre; Borsdorf, Helko

    2015-09-11

    Acesulfame is a known indicator that is used to identify the introduction of domestic wastewater into water systems. It is negatively charged and highly water-soluble at environmental pH values. In this study, a molecularly imprinted polymer (MIP) was synthesized for negatively charged acesulfame and successfully applied for the selective solid phase extraction (SPE) of acesulfame from influent and effluent wastewater samples. (Vinylbenzyl)trimethylammonium chloride (VBTA) was used as a novel phase transfer reagent, which enhanced the solubility of negatively charged acesulfame in the organic solvent (porogen) and served as a functional monomer in MIP synthesis. Different molecularly imprinted polymers were synthesized to optimize the extraction capability of acesulfame. The different materials were evaluated using equilibrium rebinding experiments, selectivity experiments and scanning electron microscopy (SEM). The most efficient MIP was used in a molecularly imprinted-solid phase extraction (MISPE) protocol to extract acesulfame from wastewater samples. Using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS-MS) analysis, detection and quantification limits were achieved at 0.12μgL(-1) and 0.35μgL(-1), respectively. Certain cross selectivity for the chemical compounds containing negatively charged sulfonamide functional group was observed during selectivity experiments. PMID:26256920

  6. Enhanced spectrofluorimetric determination of aflatoxin M1 in liquid milk after magnetic solid phase extraction.

    PubMed

    Hashemi, Mahdi; Taherimaslak, Zohreh; Rashidi, Somayeh

    2014-07-15

    A simple and sensitive method using magnetic solid phase extraction (MSPE) followed by spectrofluorimetric detection has been developed for separation and determination of aflatoxin M1 (AFM1) in liquid milk. The method is based on the extraction of AFM1 on the modified magnetic nanoparticles (MMNPs) and subsequent derivatization of extracted AFM1 to AFM1 hemi-acetal derivative (AFM2a) by reaction with trifluoroacetic acid (TFA) for spectrofluorimetric detection. Magnetic nanoparticles (MNPs) coated by 3-(trimethoxysilyl)-1-propantiol (TMSPT) and modified with 2-amino-5-mercapto-1,3,4-thiadiazole (AMT) were used as adsorbent in MSPE procedure. Influential parameters affecting the extraction efficiency were investigated and optimized. Under the optimum conditions the calibration curve for AFM1 determination showed good linearity in the range 0.030-10.0 μg L(-1) (R(2) = 0.9991). The repeatability and reproducibility (RSD%) for 0.050 μg L(-1) of AFM1 were 4.5% and 5.3%, respectively and limit of detection limit (S/N = 3) was estimated to be 0.010 μg L(-1). The developed method was successfully applied for extraction of AFM1 from spiked liquid milk and natural contaminated liquid milk. The good spiked recoveries ranging from 91.6% to 96.1% were obtained. The results demonstrated that the developed method is simple, inexpensive, accurate and remarkably free from interference effects. PMID:24691373

  7. Enhanced spectrofluorimetric determination of aflatoxin M1 in liquid milk after magnetic solid phase extraction

    NASA Astrophysics Data System (ADS)

    Hashemi, Mahdi; Taherimaslak, Zohreh; Rashidi, Somayeh

    2014-07-01

    A simple and sensitive method using magnetic solid phase extraction (MSPE) followed by spectrofluorimetric detection has been developed for separation and determination of aflatoxin M1 (AFM1) in liquid milk. The method is based on the extraction of AFM1 on the modified magnetic nanoparticles (MMNPs) and subsequent derivatization of extracted AFM1 to AFM1 hemi-acetal derivative (AFM2a) by reaction with trifluoroacetic acid (TFA) for spectrofluorimetric detection. Magnetic nanoparticles (MNPs) coated by 3-(trimethoxysilyl)-1-propantiol (TMSPT) and modified with 2-amino-5-mercapto-1,3,4-thiadiazole (AMT) were used as adsorbent in MSPE procedure. Influential parameters affecting the extraction efficiency were investigated and optimized. Under the optimum conditions the calibration curve for AFM1 determination showed good linearity in the range 0.030-10.0 μg L-1 (R2 = 0.9991). The repeatability and reproducibility (RSD%) for 0.050 μg L-1 of AFM1 were 4.5% and 5.3%, respectively and limit of detection limit (S/N = 3) was estimated to be 0.010 μg L-1. The developed method was successfully applied for extraction of AFM1 from spiked liquid milk and natural contaminated liquid milk. The good spiked recoveries ranging from 91.6% to 96.1% were obtained. The results demonstrated that the developed method is simple, inexpensive, accurate and remarkably free from interference effects.

  8. [Corrected Title: Solid-Phase Extraction of Polar Compounds from Water] Automated Electrostatics Environmental Chamber

    NASA Technical Reports Server (NTRS)

    Sauer, Richard; Rutz, Jeffrey; Schultz, John

    2005-01-01

    A solid-phase extraction (SPE) process has been developed for removing alcohols, carboxylic acids, aldehydes, ketones, amines, and other polar organic compounds from water. This process can be either a subprocess of a water-reclamation process or a means of extracting organic compounds from water samples for gas-chromatographic analysis. This SPE process is an attractive alternative to an Environmental Protection Administration liquid-liquid extraction process that generates some pollution and does not work in a microgravitational environment. In this SPE process, one forces a water sample through a resin bed by use of positive pressure on the upstream side and/or suction on the downstream side, thereby causing organic compounds from the water to be adsorbed onto the resin. If gas-chromatographic analysis is to be done, the resin is dried by use of a suitable gas, then the adsorbed compounds are extracted from the resin by use of a solvent. Unlike the liquid-liquid process, the SPE process works in both microgravity and Earth gravity. In comparison with the liquid-liquid process, the SPE process is more efficient, extracts a wider range of organic compounds, generates less pollution, and costs less.

  9. High-throughput biopolymer desalting by solid-phase extraction prior to mass spectrometric analysis.

    PubMed

    Gilar, M; Belenky, A; Wang, B H

    2001-06-29

    In the last 10 years mass spectrometry (MS) has become an important method for analysis of peptides, proteins and DNA. It was recently utilized for accurate high-throughput protein identification, sequencing and DNA genotyping. The presence of non-volatile buffers compromises sensitivity and accuracy of MS biopolymer analysis; it is essential to remove sample contaminants prior to analysis. We have developed a fast and efficient method for desalting of DNA oligonucleotides and peptides using 96-well solid-phase extraction plates packed with 5 mg of Waters Oasis HLB sorbent (Waters, Milford, MA, USA). This reversed-phase sorbent retains the biopolymer analytes, while non-retained inorganic ions are washed out with pure deionized water. DNA oligonucleotides or peptides are eluted using a small amount (20-100 microl) of acetonitrile-water (70:30, v/v) solution. The SPE desalting performance meets the requirements for MS applications such as protein digest analysis and DNA genotyping. PMID:11461010

  10. Recent Developments in Solid-Phase Extraction for Near and Attenuated Total Reflection Infrared Spectroscopic Analysis.

    PubMed

    Huck, Christian W

    2016-01-01

    A review with more than 100 references on the principles and recent developments in the solid-phase extraction (SPE) prior and for in situ near and attenuated total reflection (ATR) infrared spectroscopic analysis is presented. New materials, chromatographic modalities, experimental setups and configurations are described. Their advantages for fast sample preparation for distinct classes of compounds containing different functional groups in order to enhance selectivity and sensitivity are discussed and compared. This is the first review highlighting both the fundamentals of SPE, near and ATR spectroscopy with a view to real sample applicability and routine analysis. Most of real sample analyses examples are found in environmental research, followed by food- and bioanalysis. In this contribution a comprehensive overview of the most potent SPE-NIR and SPE-ATR approaches is summarized and provided. PMID:27187347

  11. Ionic liquid-modified materials for solid-phase extraction and separation: a review.

    PubMed

    Vidal, Lorena; Riekkola, Marja-Liisa; Canals, Antonio

    2012-02-17

    In recent years, materials science has propelled to the research forefront. Ionic liquids with unique and fascinating properties have also left their footprints to the developments of materials science during the last years. In this review we highlight some of their recent advances and provide an overview at the current status of ionic liquid-modified materials applied in solid-phase extraction, liquid and gas chromatography and capillary electrochromatography with reference to recent applications. In addition, the potential of ionic liquids in the modification of capillary inner wall in capillary electrophoresis is demonstrated. The main target material modified with ionic liquids is silica, but polymers and monoliths have recently joined the studies. Although imidazolium is still clearly the most commonly used ionic liquid for the covalently modification of materials, the exploitation of pyridinium and phosphonium will most probably increase in the future. PMID:22244164

  12. Quantitative separation of zinc traces from cadmium matrices by solid-phase extraction with polyurethane foam.

    PubMed

    Santiago de Jesus, D; Souza de Carvalho, M; Spínola Costa, A C; Costa Ferreira, S L

    1998-08-01

    A system for separation of zinc traces from large amounts of cadmium is proposed in this paper. It is based on the solid-phase extraction of the zinc in the form of thiocyanate complexes by the polyurethane foam. The following parameters were studied: effect of pH and of the thiocyanate concentration on the zinc extraction, shaking time required for quantitative extraction, amount of PU foam necessary for complete extraction, conditions for the separation of zinc from cadmium, influence of other cations and anions on the zinc sorption by PU foam, and required conditions for back extraction of zinc from the PU foam. The results show that zinc traces can be separated from large amounts of cadmium at pH 3.0+/-0.50, with the range of thiocyanate concentration from 0.15 to 0.20 mol l(-1), and the shaking time of 5 min. The back extraction of zinc can be done by shaking it with water for 10 min. Calcium, barium, strontium, magnesium, aluminum, nickel and iron(II) are efficiently separated. Iron(III), copper(II) and cobalt(II) are extracted simultaneously with zinc, but the iron reduction with ascorbic acid and the use of citrate to mask copper(II) and cobalt(II) increase the selectivity of the zinc extraction. The anions nitrate, chloride, sulfate, acetate, thiosulphate, tartarate, oxalate, fluoride, citrate, and carbonate do not affect the zinc extraction. Phosphate and EDTA must be absent. The method proposed was applied to determine zinc in cadmium salts using 4-(2-pyridylazo)-resorcinol (PAR) as a spectrophotometric reagent. The result achieved did not show significant difference in the accuracy and precision (95% confidence level) with those obtained by ICP-AES analysis. PMID:18967283

  13. Utility of solid phase extraction for spectrophotometric determination of gold in water, jewel and ore samples.

    PubMed

    Amin, Alaa S

    2010-12-01

    A highly sensitive, selective and rapid method for the determination μg L(-1) level of Au(III) based on the rapid reaction of Au(III) with 2,3-dichloro-6-(3-carboxy-2-hydroxy-1-naphthylazo)quinoxaline (DCHNAQ) and the solid phase extraction of the colored complex with a reversed phase polymer-based C18 cartridge have been developed. The DCHNAQ reacted with Au(III) to form a violet complex of a molar ratio 3:1 [DCHNAQ to Au(III)] in the presence of 5.0 M of phosphoric acid solution and Triton X-100 medium. This complex was enriched by the solid phase extraction with a polymer-based C18 cartridge. The enrichment factor of 100 was achieved. The molar absorptivity of the complex is 2.73×10(5) l mol(-1) cm(-1) at 633 nm in the measured solution. The system obeys Beer's law in the range of 0.02-1.30 μg ml(-1), whereas the optimum concentration ranges obtained from Ringbom plot was 0.08-1.24 μg ml(-1). The relative standard deviation for ten replicates sample of 0.6 μg ml(-1) level is 1.28%. The detection and quantification limits, are 6.1 and 19.5 ng ml(-1) in the original sample. This method was applied to the determination of gold in water, jewel and ore samples with good results comparing to the GFAAS method. PMID:20884285

  14. Magnetic solid-phase extraction using carbon nanotubes as sorbents: a review.

    PubMed

    Herrero-Latorre, C; Barciela-García, J; García-Martín, S; Peña-Crecente, R M; Otárola-Jiménez, J

    2015-09-10

    Magnetic solid-phase extraction (M-SPE) is a procedure based on the use of magnetic sorbents for the separation and preconcentration of different organic and inorganic analytes from large sample volumes. The magnetic sorbent is added to the sample solution and the target analyte is adsorbed onto the surface of the magnetic sorbent particles (M-SPs). Analyte-M-SPs are separated from the sample solution by applying an external magnetic field and, after elution with the appropriate solvent, the recovered analyte is analyzed. This approach has several advantages over traditional solid phase extraction as it avoids time-consuming and tedious on-column SPE procedures and it provides a rapid and simple analyte separation that avoids the need for centrifugation or filtration steps. As a consequence, in the past few years a great deal of research has been focused on M-SPE, including the development of new sorbents and novel automation strategies. In recent years, the use of magnetic carbon nanotubes (M-CNTs) as a sorption substrate in M-SPE has become an active area of research. These materials have exceptional mechanical, electrical, optical and magnetic properties and they also have an extremely large surface area and varied possibilities for functionalization. This review covers the synthesis of M-CNTs and the different approaches for the use of these compounds in M-SPE. The performance, general characteristics and applications of M-SPE based on magnetic carbon nanotubes for organic and inorganic analysis have been evaluated on the basis of more than 110 references. Finally, some important challenges with respect the use of magnetic carbon nanotubes in M-SPE are discussed. PMID:26388472

  15. Use of solid-phase extraction systems to improve the sensitivity of Artemia bioassays for trichothecene mycotoxins.

    PubMed

    Hoke, S H; Carley, C M; Johnson, E T; Broski, F H

    1987-01-01

    Solid-phase extraction was used to preconcentrate trichothecene mycotoxins from rivers and streams in order to develop and improve a rapid and sensitive bioassay using the brine shrimp Artemia salina. For T-2 toxin, HT-2 toxin, and 4,15-diacetoxyscirpenol, LC50 values obtained were 172, 600, and 700 micrograms/L, respectively. The LC50 for 4-deoxynivalenol was 21 mg/L. A more than 5-fold increase in sensitivity was observed when solid-phase extraction (SPE) was used in conjunction with the Artemia bioassay. For T-2 toxin, HT-2 toxin, and 4,15-diacetoxyscirpenol, LC50/SPE values after solid-phase extraction were 21, 83, and 130 micrograms/L. The use of river and stream waters and chlorinated water did not seem to interfere with the bioassay. PMID:3624171

  16. Magnetic solid-phase extraction of protein with deep eutectic solvent immobilized magnetic graphene oxide nanoparticles.

    PubMed

    Xu, Kaijia; Wang, Yuzhi; Ding, Xueqin; Huang, Yanhua; Li, Na; Wen, Qian

    2016-02-01

    As a new type of green solvent, four kinds of choline chloride (ChCl)-based deep eutectic solvents (DESs) have been synthesized, and then a core-shell structure magnetic graphene oxide (Fe3O4-NH2@GO) nanoparticles have been prepared and coated with the ChCl-based DESs. Magnetic solid-phase extraction (MSPE) based Fe3O4-NH2@GO@DES was studied for the first time for the extraction of proteins. The characteristic results of vibrating sample magnetometer (VSM), X-ray diffraction (XRD), Fourier transform infrared spectrometry (FT-IR), thermal gravimetric analysis (TGA) and field emission scanning electron microscopy (FESEM) indicated the successful preparation of Fe3O4-NH2@GO@DES. The concentrations of proteins in studies were determined by a UV-vis spectrophotometer. The advantages of Fe3O4-NH2@GO@DES in protein extraction were compared with Fe3O4-NH2@GO and Fe3O4-NH2, and Fe3O4-NH2@GO@ChCl-glycerol was selected as the suitable extraction solvent. The influence factors of the extraction process such as the pH value, the temperature, the extraction time, the concentration of protein and the amount of Fe3O4-NH2@GO@ChCl-glycerol were evaluated. Desorption experimental result showed 98.73% of BSA could be eluted from the solid extractant with 0.1 mol/L Na2HPO4 solution contained 1 mol/L NaCl. Besides, the conformation of BSA was not changed during the elution by the investigation of circular dichromism (CD) spectra. Furthermore, the analysis of real sample demonstrated that the prepared magnetic nanoparticles did have extraction ability on proteins in bovine whole blood. PMID:26653436

  17. Bioactive phenols in algae: the application of pressurized-liquid and solid-phase extraction techniques.

    PubMed

    Onofrejová, L; Vasícková, J; Klejdus, B; Stratil, P; Misurcová, L; Krácmar, S; Kopecký, J; Vacek, J

    2010-01-20

    A new extraction technique based on the off-line combination of pressurized-liquid with solid-phase extraction (PLE-SPE) is described. The method was used for the extraction of bioactive phenolic acids (protocatechuic, p-hydroxybenzoic, 2,3-dihydroxybenzoic, chlorogenic, vanillic, caffeic, p-coumaric, salicylic acid), cinnamic acid and hydroxybenzaldehydes (p-hydroxybenzaldehyde, 3,4-dihydroxybenzaldehyde, vanillin) from in vitro culture of two freshwater algae (Anabaena doliolum and Spongiochloris spongiosa) and from food products of marine macroalgae Porphyra tenera (nori) and Undaria pinnatifida (wakame). For the identification and quantification of the compounds the molecular ions [M-H](-) and specific fragments were analyzed by quadrupole mass spectrometry analyzer connected on-line with a reversed-phase HPLC system. Our analysis showed that the freshwater algae and marine algal products contained submicrogram or microgram level of above-mentioned phenols per gram of lyophilized sample. In addition, the total phenol content (Folin-Ciocalteu assay) and antioxidant activity (TEAC assay, Trolox equivalent antioxidant capacity assay) of the PLE-SPE extracts were determined and discussed. PMID:19410410

  18. Mixed micelle cloud point-magnetic dispersive μ-solid phase extraction of doxazosin and alfuzosin.

    PubMed

    Gao, Nannan; Wu, Hao; Chang, Yafen; Guo, Xiaozhen; Zhang, Lizhen; Du, Liming; Fu, Yunlong

    2015-01-01

    Mixed micelle cloud point extraction (MM-CPE) combined with magnetic dispersive μ-solid phase extraction (MD-μ-SPE) has been developed as a new approach for the extraction of doxazosin (DOX) and alfuzosin (ALF) prior to fluorescence analysis. The mixed micelle anionic surfactant sodium dodecyl sulfate and non-ionic polyoxyethylene(7.5)nonylphenylether was used as the extraction solvent in MM-CPE, and diatomite bonding Fe₃O₄ magnetic nanoparticles were used as the adsorbent in MD-μ-SPE. The method was based on MM-CPE of DOX and ALF in the surfactant-rich phase. Magnetic materials were used to retrieve the surfactant-rich phase, which easily separated from the aqueous phase under magnetic field. At optimum conditions, a linear relationship between DOX and ALF was obtained in the range of 5-300 ng mL(-1), and the limits of detection were 0.21 and 0.16 ng mL(-1), respectively. The proposed method was successfully applied for the determination of the drugs in pharmaceutical preparations, urine samples, and plasma samples. PMID:24995413

  19. Volatile composition of peppermint (Mentha piperita L.) commercial teas through solid phase extraction.

    PubMed

    Riachi, L G; Abi-Zaid, I E; Moreira, R F A; De Maria, C A B

    2012-12-01

    Volatiles from aqueous extract of peppermint commercial sachets were investigated through gas chromatography/flame ionization detection (GC/FID) and GC/mass spectrometry (MS). Samples were prepared under similar conditions as in homemade tea. Volatiles were isolated using solid phase extraction method (SPE) with Porapak Q trap followed by desorption with acetone. Estimated mean values for short and medium chain carboxylic acids (C2-C12) and ketones lay in the range of 50-64 microg kg(-1) whilst aliphatic alcohols and acyclic hydrocarbons had values lower than 6 microg kg(-1). The major volatiles were terpenes (275-382 microg kg(-1)) that reached 89 % of the total composition. A total of 16 compounds, among them dodecane, acetoin, acetol, citral, geraniol and octanoic acid have been described by the first time in peppermint tea. These findings could be attributed to the different analytical approach employed, mainly to the use of different extraction/pre-concentration techniques. Given the apparently lower proportion of terpenes in the aqueous extract it may be that the chemical properties of the peppermint essential oil are not entirely reproduced with homemade tea. PMID:24020260

  20. Optimization of cloud point extraction and solid phase extraction methods for speciation of arsenic in natural water using multivariate technique.

    PubMed

    Baig, Jameel A; Kazi, Tasneem G; Shah, Abdul Q; Arain, Mohammad B; Afridi, Hassan I; Kandhro, Ghulam A; Khan, Sumaira

    2009-09-28

    The simple and rapid pre-concentration techniques viz. cloud point extraction (CPE) and solid phase extraction (SPE) were applied for the determination of As(3+) and total inorganic arsenic (iAs) in surface and ground water samples. The As(3+) was formed complex with ammonium pyrrolidinedithiocarbamate (APDC) and extracted by surfactant-rich phases in the non-ionic surfactant Triton X-114, after centrifugation the surfactant-rich phase was diluted with 0.1 mol L(-1) HNO(3) in methanol. While total iAs in water samples was adsorbed on titanium dioxide (TiO(2)); after centrifugation, the solid phase was prepared to be slurry for determination. The extracted As species were determined by electrothermal atomic absorption spectrometry. The multivariate strategy was applied to estimate the optimum values of experimental factors for the recovery of As(3+) and total iAs by CPE and SPE. The standard addition method was used to validate the optimized methods. The obtained result showed sufficient recoveries for As(3+) and iAs (>98.0%). The concentration factor in both cases was found to be 40. PMID:19733735

  1. Preconcentration and determination of cadmium by GFAAS after solid-phase extraction with synthetic zeolite.

    PubMed

    Minamisawa, Hiroaki; Okunugi, Ryoko; Minamisawa, Mayumi; Tanaka, Satoshi; Saitoh, Kazunori; Arai, Nobumasa; Shibukawa, Masami

    2006-05-01

    The solid-phase extraction (SPE) method for the preconcentration of trace amounts of cadmium using synthetic zeolite A-4 and its determination by graphite furnace atomic absorption spectrometry (GFAAS) was investigated. The preconcentration conditions, such as the optimum pH range of the sample solution for the adsorption of cadmium and the kind of acid solution for dissolving the cadmium-adsorbed synthetic zeolite A-4, as well as the measurement conditions for the determination of cadmium by GFAAS, e.g., the ashing and atomizing temperature, were investigated. Quantitative recovery of cadmium onto zeolite A-4 from the sample solution over the pH range 2.0 - 9.0 was achieved by the batch method. After the solid-phase (cadmium-adsorbed zeolite A-4) was separated from the sample solution by a membrane filter, it was dissolved in 2.0 cm(3) of 2.0 mol dm(-3) nitric acid. An aliquot of the resulting solution was injected into the graphite furnace. In GFAAS measurements an alternate gas (Ar, 90%; O(2), 10%) was used as a sheath gas, and the ashing temperature and atomizing temperature were 400 degrees C and 1600 degrees C, respectively. The detection limit (3 sigma) for cadmium was 0.002 microg dm(-3). The relative standard deviation at 0.010 microg dm(-3) was 3.5 - 4.5% (n = 5). The proposed method has been successfully applied to the analysis of trace cadmium in environmental water samples. PMID:16770049

  2. Magnetic three-dimensional graphene solid-phase extraction of chlorophenols from honey samples.

    PubMed

    Liu, Xingli; Zhou, Xin; Wang, Chun; Wu, Qiuhua; Wang, Zhi

    2015-01-01

    A novel magnetic three-dimensional graphene nano-composite (3D-G@Fe3O4) with a high surface area was synthesised by a vacuum freeze-dried method. Due to its high surface area, specific 3D nanoporous structure and excellent magnetic properties, it can be used as a magnetic solid-phase extraction adsorbent. Some chlorophenols in a honey samples were enriched by this nanocomposite prior to their determination by HPLC with ultraviolet detection. Factors that affect the extraction efficiency, such as the amount of 3D-G@Fe3O4, extraction time, sample pH, ionic strength and desorption conditions, were investigated and optimised. Under the optimum conditions, good linearity existed in the range of 10.0-1000.0 ng g(-1). The enrichment factors of the method for the analytes were in the range from 101 to 248. The limits of detection of the method (S/N = 3) were 1.0-1.5 ng g(-1). The recoveries of the method for the analytes at spiking levels of 100.0 and 400.0 ng g(-1) were in the range of 93.2-98.9%. The results showed that the proposed method is simple, reliable and sensitive. It will be a useful tool for the routine monitoring of chlorophenols in honey products. PMID:25397363

  3. Analysis of aromatic sulfonates in water by solid-phase extraction and capillary electrophoresis.

    PubMed

    Loos, R; Niessner, R

    1998-10-01

    The separation of 14 different aromatic sulfonates of environmental concern by capillary (zone) electrophoresis (CZE) is presented. A new off-line solid-phase extraction (SPE) enrichment procedure, that is compatible with CE analysis, was developed, using the styrene-divinylbenzene adsorbent LiChrolut EN. The combined method of SPE and CE allows the determination of aromatic sulfonates in water samples in the low microgram/l range. Separations are performed with a simple sodium borate buffer at pH 9.3. Analytes are detected by UV absorbance and fluorescence emission with a Xe-lamp excitation source, and both principles are compared. The recoveries for most of the sulfonates are > 70% for the extraction from spiked tap and river water. The average method precision is < 20% for replicate analyses. Very hydrophilic sulfonates cannot be extracted by this method. The detection limit of the combined method of SPE enrichment and CE analysis is approximately 0.1 microgram/l for 200-ml water samples. The performance of the method was checked with the analysis of river and contaminated seepage water. PMID:9809447

  4. Analysis of trace dicyandiamide in stream water using solid phase extraction and liquid chromatography UV spectrometry.

    PubMed

    Qiu, Huidong; Sun, Dongdi; Gunatilake, Sameera R; She, Jinyan; Mlsna, Todd E

    2015-09-01

    An improved method for trace level quantification of dicyandiamide in stream water has been developed. This method includes sample pretreatment using solid phase extraction. The extraction procedure (including loading, washing, and eluting) used a flow rate of 1.0mL/min, and dicyandiamide was eluted with 20mL of a methanol/acetonitrile mixture (V/V=2:3), followed by pre-concentration using nitrogen evaporation and analysis with high performance liquid chromatography-ultraviolet spectroscopy (HPLC-UV). Sample extraction was carried out using a Waters Sep-Pak AC-2 Cartridge (with activated carbon). Separation was achieved on a ZIC(®)-Hydrophilic Interaction Liquid Chromatography (ZIC-HILIC) (50mm×2.1mm, 3.5μm) chromatography column and quantification was accomplished based on UV absorbance. A reliable linear relationship was obtained for the calibration curve using standard solutions (R(2)>0.999). Recoveries for dicyandiamide ranged from 84.6% to 96.8%, and the relative standard deviations (RSDs, n=3) were below 6.1% with a detection limit of 5.0ng/mL for stream water samples. PMID:26354690

  5. Rapid purification of fumonisins and their hydrolysis products with solid-phase extraction columns.

    PubMed

    Poling, S M; Plattner, R D

    1999-06-01

    Fumonisins B(3) and B(4) (FB(3) and FB(4)) were recovered from the 50:50 acetonitrile/water extract of corn cultures of a strain of Fusarium moniliforme that does not make FB(1) or FB(2) by stirring the extract with IRA-68, a weak anion-exchange resin. The fumonisins were desorbed with 5% acetic acid in the same solvent. After dilution with water, the desorbed fumonisins were separated into FB(3) (FB(3) and FA(3)) and FB(4) (FB(4), FC(4), and FA(4)) fractions with a tC(18) solid-phase extraction (SPE) cartridge. The FB(3) fraction was then separated into FB(3) and FA(3) by using an NH(2) SPE cartridge and eluting with 5% acetic acid and increasing amounts of acetonitrile in water. Finally, FB(1) and FA(3) were hydrolyzed with calcium hydroxide. After recovery from the reaction mixture using a tC(18) cartridge, the hydrolyzed and partially hydrolyzed analogues were separated and the unreacted fumonisins recovered by using an NH(2) cartridge, initially in the normal-phase mode with increasing amounts of water in acetonitrile and then in the reversed-phase mode after the addition of 5% acetic acid to the solvent and eluting in the reverse order. PMID:10794634

  6. Disks solid phase extraction based polypyrrole functionalized core-shell nanofibers mat.

    PubMed

    Qi, FeiFei; Li, XiaoQing; Yang, BiYi; Rong, Fei; Xu, Qian

    2015-11-01

    A novel disks solid phase extraction (SPE) based on polypyrrole (PPy) functionalized core-shell electrospun nanofibers mat was proposed. The performance of the established disks SPE technique was evaluated in the extraction of trace polar analytes from environmental water samples. Disulphonated (acid yellow 9) and monosulphonated azo dyes (acid orange 7 and metanil yellow) were selected as typical model analytes. Under the optimum conditions, detection limits were 0.15-0.3 μg/L for all target analytes and the enrichment coefficients were 106-121. The recoveries of sulfonated azo dyes added to typical environmental water samples were 87.6-112.3%, suggesting that the interferences of the sample matrix did not affect the enrichment. Compared with existing methods, the device in this study showed higher recovery, lower detection limit and better precision. Moreover, the miniaturized disks SPE technique for sample preparation is simple and fast, with significantly reduced sorbent bed mass (2.5 mg) and eluent volume (500 μL). These results indicate that PPy nanofibers mat-based disks SPE may be a promising device that can effectively extract the polar species in water samples. PMID:26452802

  7. Magnetic solid-phase extraction of protein by ionic liquid-coated Fe@graphene oxide.

    PubMed

    Wen, Qian; Wang, Yuzhi; Xu, Kaijia; Li, Na; Zhang, Hongmei; Yang, Qin; Zhou, Yigang

    2016-11-01

    Amino functional dicationic ionic liquid (AFDCIL) was prepared and then coated on the surface of magnetic graphene oxide (GO) as a new magnetic adsorbent (Fe@GO@AFDCIL) for the magnetic solid-phase extraction (MSPE) of protein. The Fe@GO@AFDCIL composite was characterized by vibrating sample magnetometer (VSM), X-ray diffraction (XRD), Fourier transform infrared spectrometry (FT-IR), thermal gravimetric analysis (TGA), field emission scanning electron microscopy (FESEM) and zeta-potential nanoparticles. The bovine hemoglobin (BHb) was used as the analyte, and the extraction performance of Fe@GO@AFDCIL was investigated in the MSPE procedure. The concentration of BHb in samples was determined by a UV-vis spectrophotometer. A comparative investigation of Fe@GO@AFDCIL composite and traditional IL-coated Fe@GO composites (Fe@GO@IL) exhibited the benefits of Fe@GO@AFDCIL. The adsorbed BHb could be eluted from the Fe@GO@AFDCIL by 4% sodium dodecyl sulfate (SDS) solution. The Fe@GO@AFDCIL exhibited favorable stability which could be reused at least 15 times. Under the optimized condition, the real samples were investigated, which demonstrated that the Fe@GO@AFDCIL was able to be applied in extracting bovine hemoglobin (BHb) from real biological samples. PMID:27591642

  8. Magnetic molecularly imprinted polymer for the selective extraction of quercetagetin from Calendula officinalis extract.

    PubMed

    Ma, Run-Tian; Shi, Yan-Ping

    2015-03-01

    A new magnetic molecularly imprinted polymers (MMIPs) for quercetagetin was prepared by surface molecular imprinting method using super paramagnetic core-shell nanoparticle as the supporter. Acrylamide as the functional monomer, ethyleneglycol dimethacrylate as the crosslinker and acetonitrile as the porogen were applied in the preparation process. Fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD) and Vibrating sample magnetometer (VSM) were applied to characterize the MMIPs, and High performance liquid chromatography (HPLC) was utilized to analyze the target analytes. The selectivity of quercetagetin MMIPs was evaluated according to their recognition to template and its analogues. Excellent binding for quercetagetin was observed in MMIPs adsorption experiment, and the adsorption isotherm models analysis showed that the homogeneous binding sites were distributed on the surface of the MMIPs. The MMIPs were employed as adsorbents in solid phase extraction for the determination of quercetagetin in Calendula officinalis extracts. Furthermore, this method is fast, simple and could fulfill the determination and extraction of quercetagetin from herbal extract. PMID:25618718

  9. Preparation of molecularly imprinted polymers based on magnetic nanoparticles for the selective extraction of protocatechuic acid from plant extracts.

    PubMed

    Xie, Xiaoyu; Wei, Fen; Chen, Liang; Wang, Sicen

    2015-03-01

    In this study, highly selective core-shell molecularly imprinted polymers on the surface of magnetic nanoparticles were prepared using protocatechuic acid as the template molecule. The resulting magnetic molecularly imprinted polymers were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and vibrating sample magnetometry. The binding performances of the prepared materials were evaluated by static and selective adsorption. The binding isotherms were obtained for protocatechuic acid and fitted by the Langmuir isotherm model and Freundlich isotherm model. Furthermore, the resulting materials were used as the solid-phase extraction materials coupled to high-performance liquid chromatography for the selective extraction and detection of protocatechuic acid from the extracts of Homalomena occulta and Cynomorium songaricum with the recoveries in the range 86.3-102.2%. PMID:25641806

  10. [Determination of Arsenic in Food Package Aluminum by Ultrasound Assisted Solid Phase Extraction/ICP-AES].

    PubMed

    Qin, Wen-xia; Gong, Qi; Li, Min; Deng, Li-xin; Mo, Li-shu; Li, Yan-lin

    2015-04-01

    Determination of arsenic in pure aluminum by inductively coupled plasma atomic emission spectrometry was interfered by aluminum matrix. The experiment showed that when the mass concentration of Al was greater than or equal to 5 000 times the As in the test solution, the measurement error was greater than 5%. In order to eliminate the interference, strong acid cation exchange fiber (SACEF) was used as solid phase extraction agent to adsorb Al(3+). The extraction conditions included amount of SACEF, extraction time, temperature and pH were investigated. The optimal extraction conditions were that 0.9000 g SACEF was used to extract the aluminum from the sample solution of pH 2.0 at 55 °C for 5 min with the ultrasonic assist, and in this case, the arsenic in the form of arsenic acid was not extracted and left in the solution for the determination. The results showed that after treating 10. 00 mL test solution containing 1.00 µg arsenic and 20.0 mg aluminum, arsenic did not lose. The mass concentration of residual aluminum in the raffinate was about 2,000 times the As, which had not interfered the determination of arsenic. The detection limit (3 s) was 0.027 µg · mL(-1) and quantification limit (10 s) was 0.0091 µg · mL(-1). The proposed method was successfully applied to the separation and determination of arsenic in the synthetic samples, the aluminum cans and the barbecue aluminum foil. Recovery was in the range of 98.3%-105% and RSD (n = 3) was in the range of 0.1%-4.3%. The results showed that the content of arsenic in the aluminum cans and the aluminum barbecue foil was below the limited value of national standard (GB/T 3190-2008). PMID:26197599

  11. Core-shell electrospun polybutylene terephthalate/polypyrrole hollow nanofibers for micro-solid phase extraction.

    PubMed

    Bagheri, Habib; Rezvani, Omid; Banihashemi, Solmaz

    2016-02-19

    In the present work, a new micro-solid phase extraction (μ-SPE) sorbent as an extracting medium based on core-shell nanofibers was synthesized by electrospinning. The core-shell nanofibers of polyvinylpyrrolidone-Polybutylene terephthalate/polypyrrole (PVP-PBT/PPy) were electrospun and subsequently, modified hollow nanofibers were prepared by removing the central PVP moiety. Moreover, conventional PBT/PPy was also prepared for the comparison purposes. The homogeneity and the porous surface structure of the core-shell nanofibers were confirmed by scanning electron microscopy (SEM). The applicability of the fabricated nanofibers-coating was examined by immersed μ-SPE of some selected triazine herbicides from aqueous samples and wheat grains. Subsequently, the extracted analytes were transferred into a gas chromatography (GC) after solvent desorption. Influencing parameters on the morphology of nanofiber such as elctrospinning parameters and the weight ratio of components were optimized. In addition, effects of different parameters influencing the extraction efficiency including extraction temperature, extraction time, ionic strength, sample pH, desorption temperature, and desorption time were investigated and optimized. Eventually, the developed method was validated by gas chromatography-mass spectrometry (GC-MS). At the optimum conditions, the relative standard deviation values for real water samples spiked with the selected triazines at 1 ng mL(-1) were 4-8% (n=3) and the limits of detection for the studied compounds were between 50 and 90 ng L(-1). The calibration curves for the selected triazines were in the range of 0.3-500 ng mL(-1) and regression coefficients (R(2)) were between 0.9985 and 0.9996. PMID:26810808

  12. Optimization of the extraction conditions of the volatile compounds from chili peppers by headspace solid phase micro-extraction.

    PubMed

    Junior, Stanislau Bogusz; de Marchi Tavares de Melo, Arlete; Zini, Cláudia Alcaraz; Godoy, Helena Teixeira

    2011-05-27

    A method involving headspace-solid phase micro-extraction (HS-SPME), gas chromatography with flame ionization detection (GC-FID) and gas chromatography with mass spectrometry (GC-MS) was developed and optimized to investigate the volatile composition of Capsicum chili peppers. Five SPME fibers were tested for extraction: carboxen/polydimethylsiloxane (CAR/PDMS-75μm), polydimethylsiloxane (PDMS-100μm), divinylbenzene/polydimethylsiloxane (DVB/PDMS-65μm), carbowax/divinylbenzene (CW/DVB-70μm), and divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS-50/30μm), the last of which was shown to be the most efficient fiber to trap the volatile compounds. Optimization of the extraction conditions was carried out using multivariate strategies such as factorial design and response surface methodology. Eighty three compounds were identified by GC-MS when using the optimized extraction conditions, the majority of which were esters. PMID:21227437

  13. Determination of Scopolamine in Human Saliva Using Solid Phase Extraction and LC/MS/MS

    NASA Technical Reports Server (NTRS)

    Wang, Zuwei; Vaksman, Zalman; Boyd, Jason; Putcha, Lakshmi

    2007-01-01

    Purpose: Scopolamine is the preferred treatment for motion sickness during space flight because of its quick onset of action, short half-life and favorable side-effect profile. The dose administered depends on the mode of administration and usually ranges between 0.1 and 0.8 mg. Such small doses make it difficult to detect concentrations of scopolamine in biological fluids by using conventional HPLC methods. To measure scopolamine in saliva and thereby to evaluate the pharmacokinetics of scopolamine, we developed an LC/MS/MS method using off-line solid phase extraction. Method: Samples (0.5mL) were loaded onto Waters Oasis HLB co-polymer cartridges (10 mg, 1 mL) and eluted with 0.5 mL methanol without evaporation and reconstitution. HPLC separation of the eluted sample was performed using an Agilent Zorbax SB-CN column (50 x 2.1 mm) at a flow rate of 0.2 mL/min for 4 minutes. The mobile phase for separation was 90:10 (v/v) methanol: ammonium acetate (2 mM) in water, pH 5.0 +/- 0.1. Concentrations of scopolamine were determined using a Micromass Quattro Micro(TM) mass spectrometer with electrospray ionization (ESI). ESI mass spectra were acquired in positive ion mode with multiple reaction monitoring for the determination of scopolamine m/z = 304.2 yields 138.1 and internal standard (IS) hyoscyamine m/z = 290.2 yields 124.1. Results: The method is rapid, reproducible, specific and has the following parameters: scopolamine and the IS are eluted at 1.7 and 3.2 min respectively. The linear range is 50-5000 pg/mL for scopolamine in saliva with correlation coefficients > 0.99 with a CV < 0.5 %. The intra-day and inter-day CVs are < 15 % for quality control samples with concentrations of 75, 300, 750 and 3000 pg/mL of scopolamine in human saliva. Conclusion: Solid phase extraction allows more rapid sample preparation and greater precision than liquid extraction. Furthermore, we increased the sensitivity and specificity by adjusting the LC mobile phase and using an MS

  14. Proposed Guidelines for Solid Phase Extraction of Suwannee River Dissolved Organic Matter.

    PubMed

    Li, Yan; Harir, Mourad; Lucio, Marianna; Kanawati, Basem; Smirnov, Kirill; Flerus, Ruth; Koch, Boris P; Schmitt-Kopplin, Philippe; Hertkorn, Norbert

    2016-07-01

    This paper proposes improved guidelines for dissolved organic matter (DOM) isolation by solid phase extraction (SPE) with a styrene-divinylbenzene copolymer (PPL) sorbent, which has become an established method for the isolation of DOM from natural waters, because of its ease of application and appreciable carbon recovery. Suwannee River water was selected to systematically study the effects of critical SPE variables such as loading mass, concentration, flow rate, and up-scaling on the extraction selectivity of the PPL sorbent. High-field Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) and proton nuclear magnetic resonance ((1)H NMR) spectroscopy were performed to interpret the DOM chemical space of eluates, as well as permeates and wash liquids with molecular resolution. Up to 89% dissolved organic carbon (DOC) recovery was obtained with a DOC/PPL mass ratio of 1:800 at a DOC concentration of 20 mg/L. With the application of larger loading volumes, low proportions of highly oxygenated compounds were retained on the PPL sorbent. The effects of the flow rate on the extraction selectivity of the sorbent were marginal. Up-scaling had a limited effect on the extraction selectivity with the exception of increased self-esterification with a methanol solvent, resulting in methyl ester groups. Furthermore, the SPE/PPL extract exhibited highly authentic characteristics in comparison with original water and reverse osmosis samples. These findings will be useful for reproducibly isolating DOM with representative molecular compositions from various sources and concentrations and minimizing potential inconsistencies among interlaboratory comparative studies. PMID:27176119

  15. Micro-solid phase extraction of perfluorinated carboxylic acids from human plasma.

    PubMed

    Lashgari, Maryam; Lee, Hian Kee

    2016-02-01

    Micro-solid phase extraction (μ-SPE), with liquid chromatography-tandem mass spectrometry has been developed for the determination of trace levels of perfluorinated carboxylic acids (PFCAs) in human plasma. The μ-SPE sorbent was surfactant-templated mesoporous silica. Extraction time, desorption time and salt concentration were chosen as the most effective parameters and were optimized simultaneously by use of central composite design. Under the optimized extraction conditions, good linearity in the range of 100 and 5000ngL(-1) was obtained with coefficients of determination of between 0.986 and 0.995. The limits of detection (at a signal to noise ratio of 3) were measured to be in the range of between 21.23 and 65.07ngL(-1), and limits of quantification (at a signal to noise ratio of 10) were in the range of between 70.77 and 216.92ngL(-1). The relative recoveries of spiked PFCAs in different samples were in the range of between 87.58 and 102.45%. As expected from the global distribution of PFCs, contaminations at low levels (less than 200ngL(-1)) were detected (with the highest concentration recorded for perfluorooctanoic acid (PFOA)). Considering the complex nature of biological samples and the issue of matrix effects in the analysis of PFCAs, μ-SPE as an extraction method was shown to be advantageous; it combined extraction and concentration in one single step with no additional sample clean-up, and was able to remove significant matrix interferences. PMID:26795278

  16. [Determination of residual sulfonamides in meat by high performance liquid chromatography with solid-phase extraction].

    PubMed

    Zhang, Yan; Wu, Yinliang

    2005-11-01

    A method was developed for determining residual sulfonamides (SAs) such as sulfamethazine (SM2), sulfamonomethoxine (SMM), sulfamethiazole (SMZ), sulfadimethoxine (SDM) and sulfaquinoxaline (SQ) in pork and chicken using solid-phase extraction (SPE) and high performance liquid chromatography (HPLC) with a photodiode array detector. The samples were extracted with ethyl acetate. An NH2 column was used for clean up. For the HPLC determination, an Intersil ODS-2 column was used with a mixture of methanol-acetonitrile-water-acetic acid (2: 2: 9: 0.2, v/v) as the mobile phase. The detection limits (S/N = 3) were 3 microg/kg for SM2, SMM and SMZ, and 7 microg/kg for SDM and SQ. The quantitation limits (S/N = 10) were 10 microg/kg for SM2, SMM and SMZ, and 25 microg/kg for SDM and SQ. The linear ranges were 30 - 5 000 microg/L for SM2, SMM and SMZ, and 60 - 5 000 microg/L for SDM and SQ. The recoveries were between 73.2% and 97.3% with the relative standard deviations between 2.5% and 11.6% originated from the spiked level of 50 microg/kg. PMID:16498995

  17. Evaluation of phenylene-bridged periodic mesoporous organosilica as a stationary phase for solid phase extraction.

    PubMed

    Carpio, A; Esquivel, D; Arce, L; Romero-Salguero, F J; Van Der Voort, P; Jiménez-Sanchidrián, C; Válcarcel, M

    2014-11-28

    A periodic mesoporous organosilica, in particular, a phenylene-bridged material (Ph-PMO), was evaluated for the first time as a sorbent for retaining and eluting fenuron, simazine, atrazine, carbaryl and terbutryn in grape must by solid phase extraction (SPE) prior to their determination with capillary electrophoresis coupled with ultraviolet detection (CE-UV). The analytes were used as model compounds to demonstrate the potential of Ph-PMO for increasing the sensitivity of CE. Under optimal conditions, the limits of detection for the analytes ranged from 0.6 to 4 μg/L, and their limits of quantitation from 2 to 10 μg/L. These values were comparable and, in some cases, even better than those obtained with C18 and HLB materials. Ph-PMO was characterized physicochemically by X-ray diffraction analysis, N2 adsorption-desorption measurements and laser diffraction particle sizing. The sorbent afforded the extraction of atrazine, carbaryl and terbutryn from grape must with mean recoveries ranging from 86 to 105%. Therefore, periodic mesoporous organosilicas possess a high potential as SPE materials. PMID:25454127

  18. Application of solid-phase extraction for determination of phenolic compounds in barrique wines.

    PubMed

    Matejícek, D; Klejdus, B; Mikes, O; Sterbová, D; Kubán, V

    2003-09-01

    A fast, selective and sensitive chromatographic method has been developed for determination of gallic, protocatechuic, p-hydroxybenzoic, vanillic, caffeic, syringic, p-coumaric, benzoic, ferulic, sinapic, cinnamic, and ellagic acids and p-hydroxybenzaldehyde, vanillin, syringaldehyde, 2-furfural, 5-methylfurfural, and 5-methoxyfurfural. The compounds from untreated wine samples were pre-concentrated and cleaned using solid-phase extraction on RP-105 polymeric sorbent. The cartridge was conditioned with methanol and water. Co-extracted ballast substances were rinsed from the sorbent with 0.1 mol L(-1) hydrochloric acid-methanol, 1:4 (v/ v). Retained phenolic compounds were selectively eluted with diethyl ether. A linear mobile phase gradient containing 0.3% acetic acid and methanol was used for final baseline chromatographic separation on a Hypersil BDS C18 column. Limits of detection (LOD=3 s(bl)) in the range 5.2 to 181.2 microg L(-1), resolution (R) better than 1.7, and repeatability of 2.7-5.1% (RSD for real samples) were achieved. The method was applied for quantification of individual phenolic compounds in barrique wines. PMID:12923605

  19. Ferrofluid based dispersive-solid phase extraction for spectrophotometric determination of dyes.

    PubMed

    Davudabadi Farahani, Malihe; Shemirani, Farzaneh

    2013-10-01

    For the first time, ferrofluid based dispersive-solid phase extraction (D-SPE) has been applied for determination of trace levels of dyes in aqueous and fish samples. The contaminant used as a model compound was crystal violet (CV), a cationic dye, and was preconcentrated without any derivatization or ion-pair formation. The method is based on rapid injection of ferrofluid into the aqueous sample by a syringe. The sample preparation time is decreased by the fact that the sorbent dispersed in the bulk solution and extraction can be achieved very fast. In this way, the separation of sorbent from the aqueous bulk was achieved by a magnet, and no centrifugation is required. These significant features which obtained with this method are of key interest for routine trace laboratory analysis. The influence of different variables on D-SPE was investigated. Under optimum conditions, the calibration graph was linear over the range of 3.3-90 μg L(-1), and the enrichment factor (EF) 267 was obtained. Detection limit was 1.51 μg L(-1) (n=7), and the relative standard deviation of 5.6% at 50 ng mL(-1) was obtained (n=7). The proposed method was successfully applied for the determination of crystal violet in various samples. PMID:23849184

  20. A rapid solid-phase extraction fluorometric method for thiamine and riboflavin in salmonid eggs

    USGS Publications Warehouse

    Zajicek, J.L.; Tillitt, D.E.; Brown, S.B.; Brown, L.R.; Honeyfield, D.C.; Fitzsimons, J.D.

    2005-01-01

    A new method has been developed and successfully applied to the selective measurement of thiamine (nonphosphorylated), total thiamine (sum of thiamine, thiamine monophosphate [TMP], thiamine diphosphate [TDP], and thiamine triphosphate [TTP]), and potentially interfering riboflavin in acidic (2% trichloroacetic acid) extracts of selected salmonid and walleye egg samples. Acidic extracts of eggs were applied directly to end-capped C18, reversed-phase solid-phase extraction (SPE) columns and separated into three fractions by elution with mixtures of PO4 buffer (pH 2), methanol (10%), and acetonitrile (20%). All thiamine compounds recovered in the first two fractions were oxidized to their corresponding thiochromes with alkaline potassium hexacyanoferrate, and we measured the thiochrome fluorescence (excitation at 360 nm, emission at 460 nm) in a 96-well microplate reader. Riboflavin, recovered in third fraction (eluted with pH 2, 20% acetonitrile), was analyzed directly by measuring the fluorescence of this fraction (excitation at 450 nm, emission at 530 nm). Significant portions of the phosphate esters of thiamine (TMP, TDP, and presumably TTP), when present at low concentrations (< 10 nmol of total -thiamine per gram of egg), were not retained by the 100-mg SPE column, and were collected directly during sample loading and in a subsequent phosphoric acid rinse as fraction 1. Free thiamine (nonphosphorylated) and remaining portions of the TDP and TMP were then eluted in the second fraction with 10% methanol/PO4 buffer, whereas the un-ionized, relatively nonpolar riboflavin was eluted in the third fraction with 20% acetonitrile. This new method uses a traditional sample homogenization of egg tissue to extract thiamine compounds into 2% trichlororacetic acid solution; an inexpensive, commercially available SPE column; small amounts of sample (0.5-1 g); microliter volumes of solvents per sample; a traditional, relatively nonhazardous, oxidation of thiamine compounds to

  1. Clarification of Reconstituted Frozen Orange Juice Concentrate by Continuous Flow Centrifugation for Limonin Glucoside Solid Phase Extraction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The clarification of reconstituted frozen orange juice concentrate by continuous-flow centrifugation in preparation to being applied to a solid phase extraction column for the isolation of limonin glucoside has been evaluated. Clarification experiments spanning over three different flow rates (325,...

  2. Simultaneous solid phase extraction and derivatization of aliphatic primary amines prior to separation and UV-absorbance detection.

    PubMed

    Felhofer, Jessica L; Scida, Karen; Penick, Mark; Willis, Peter A; Garcia, Carlos D

    2013-10-15

    To overcome the problem of poor sensitivity of capillary electrophoresis-UV absorbance for the detection of aliphatic amines, a solid phase extraction and derivatization scheme was developed. This work demonstrates successful coupling of amines to a chromophore immobilized on a solid phase and subsequent cleavage and analysis. Although the analysis of many types of amines is relevant for myriad applications, this paper focuses on the derivatization and separation of amines with environmental relevance. This work aims to provide the foundations for future developments of an integrated sample preparation microreactor capable of performing simultaneous derivatization, preconcentration, and sample cleanup for sensitive analysis of primary amines. PMID:24054648

  3. Simultaneous Solid Phase Extraction and Derivatization of Aliphatic Primary Amines Prior to Separation and UV-Absorbance Detection

    PubMed Central

    Felhofer, Jessica L.; Scida, Karen; Penick, Mark; Willis, Peter A.; Garcia, Carlos D.

    2013-01-01

    To overcome the problem of poor sensitivity of capillary electrophoresis-UV absorbance for the detection of aliphatic amines, a solid phase extraction and derivatization scheme was developed. This work demonstrates successful coupling of amines to a chromophore immobilized on a solid phase and subsequent cleavage and analysis. Although the analysis of many types of amines is relevant for myriad applications, this paper focuses on the derivatization and separation of amines with environmental relevance. This work aims to provide the foundations for future developments of an integrated sample preparation microreactor capable of performing simultaneous derivatization, preconcentration, and sample cleanup for sensitive analysis of primary amines. PMID:24054648

  4. Microwave-assisted extraction and high-throughput monolithic-polymer-based micro-solid-phase extraction of organophosphorus, triazole, and organochlorine residues in apple.

    PubMed

    Bagheri, Habib; Es'haghi, Ali; Es-Haghi, Ali; Basiripour, Fatemeh

    2016-02-01

    A high-throughput micro-solid-phase extraction device based on a 96-well plate was constructed and applied to the determination of pesticide residues in various apple samples. Butyl methacrylate and ethylene glycol dimethacrylate were copolymerized as a monolithic polymer and placed in the cylindrically shaped stainless-steel meshes of 96-micro-solid-phase extraction device and used as an extracting unit. Before the micro-solid-phase extraction, microwave-assisted extraction was employed to facilitate the transfer of the pesticide residues from the apple matrix to liquid media. Then, 1 mL of the aquatic samples was transferred into the 96-well plate and the 96-micro-solid-phase extraction device was applied for the extraction of the selected pesticides. Influential parameters, such as sorbent-to-sorbent reproducibility, microwave-assisted extraction time, ionic strength and micro-solid-phase extraction time, were optimized. The limits of quantitation were below 120 μg/kg, which are lower than the maximum residue limits. The developed method was successfully implemented for the extraction and determination of the selected pesticides from 20 different apple samples gathered from local markets. Phosalone was identified and quantified at the concentration level of 147 (±16.4) μg/kg in one of the samples. PMID:26614571

  5. Solid phase extraction of trace amount of Cu(II) using functionalized-graphene

    NASA Astrophysics Data System (ADS)

    Moghimi, Ali

    2013-11-01

    A novel and selective method for the fast determination of trace amounts of Cu(II) ions in water samples has been developed. The first organic-solution-processable functionalized-graphene (SPF-Graphene) hybrid material with porphyrins, porphyrin-graphene nanohybrid, 5-(4-aminophenyl)-10, 15, 20-triphenyl porphyrin and its photophysical properties including optical (TPP) and grapheme oxide molecules covalently bonded together via an amide bond (TPP-NHCO-SPFGraphene) were used as absorbent for extraction of Cu(II) ions by solid phase extraction method. The complexes were eluted with HNO3 (2 M) 10% (vol/vol) methanol in acetone and determined the analyte by flame atomic absorption spectrometry. The procedure is based on the selective formation of Cu(II) at optimum pH by elution with organic eluents and determination by flame atomic absorption spectrometry. The method is based on complex formation on the surface of the ENVI-18 DISK™ disks modified porphyrin-graphene nanohybrid, 5-(4-aminophenyl)-10,15,20-triphenyl porphyrin (TPP) and grapheme oxide molecules covalently bonded together via an amide bond (TPP-NHCO-SPFGraphene) followed by stripping of the retained species by minimum amounts of appropriate organic solvents. The elution is efficient and quantitative. The effect of potential interfering ions, pH, TPP-NHCO-SPFGraphene, amount, stripping solvent, and sample flow rate were also investigated. Under the optimal experimental conditions, the break-through volume was found to about 1000 mL providing a preconcentration factor of 600. The maximum capacity of the disks was found to be 398 ± 3 μg for Cu2+. The limit of detection of the proposed method is 5 ng per 1000 mL. The method was applied to the extraction and recovery of copper in different water samples.

  6. Solid-phase dispersive extraction method for analysis of benzodiazepine drugs in serum and urine samples.

    PubMed

    Saito, Koichi; Kikuchi, Yuu; Saito, Rieko

    2014-11-01

    A simple yet highly efficient pretreatment method called solid-phase dispersive extraction (SPDE) was developed and used in combination with liquid chromatography/time-of-flight mass spectrometry (LC/TOF-MS) for the analysis of benzodiazepines (BZPs) in serum and urine samples. By using a custom-made centrifugal filter, SPDE could be performed in a closed system, thereby minimizing exposure to infectious microbes or hazardous chemicals. The limit of detection and the limit of quantification of nine BZPs were 1-10 and 5-50ng/mL, respectively. The average recoveries of BZPs from pooled serum samples spiked at 50 and 500ng/mL were 89.6-105.0% (RSD: 2.1-6.8%) and 93.6-110.4% (RSD: 2.1-4.2%), respectively, and those from urine samples were 88.7-105.5% (RSD: 2.9-6.4%) and 91.5-101.1% (RSD: 3.6-5.5%), respectively. SPDE-LC/TOF-MS has potential application in forensic science and emergency medicine. PMID:25126966

  7. Plasma mitomycin C concentrations determined by HPLC coupled to solid-phase extraction.

    PubMed

    Paroni, R; Arcelloni, C; De Vecchi, E; Fermo, I; Mauri, D; Colombo, R

    1997-04-01

    The aim of this study was to set up a method for quantification of plasma mitomycin C (MMC) concentrations during intravesical chemotherapy delivered in the presence of local bladder hyperthermia (HT). In comparison with existing methods, this assay, characterized by relative simplicity and efficiency, resulted in the facilitation of performance with nondedicated instrumentation or nonspecialized staff. Purification from plasma matrix was carried out by solid-phase extraction under vaccuum. The purified drug was then collected directly into the vials of the HPLC autosampler. Chromatographic analysis was performed on a reversed-phase C18 column with water:acetonitrile (85:15 by vol) as the mobile phase and the UV detector set at 365 nm. The use of porfiromycin as internal standard provided a method with good within-day precision (CV 6.0% at 5 micrograms/L, n = 6), linearity (0.5-50 micrograms/L), and specificity. The lower limit of detection (< or = 0.5 microgram/L) proved to be suitable for plasma pharmacokinetics monitoring in two tested patients treated with MMC + HT for superficial bladder cancer. PMID:9105262

  8. A solid phase extraction-based platform for rapid phosphoproteomic analysis

    PubMed Central

    Dephoure, Noah; Gygi, Steven P.

    2011-01-01

    Protein phosphorylation is among the most common and intensely studied post-translational protein modification. It plays crucial roles in virtually all cellular processes and has been implicated in numerous human diseases, including cancer. Traditional biochemical and genetic methods for identifying and monitoring sites of phosphorylation are laborious and slow and in recent years have largely been replaced by mass spectrometric analysis. Improved methods for phosphopeptide enrichment coupled with faster and more sensitive mass spectrometers have led to an explosion in the size of phosphoproteomic datasets. However, wider application of these methods is limited by equipment costs and the resultant high demand for instrument time as well as by a technology gap between biologists and mass spectrometrists. Here we describe a modified two-step enrichment strategy that employs lysC digestion and step elution from self-packed strong cation exchange (SCX) solid phase extraction (SPE) columns followed by immobilized metal ion affinity chromatography (IMAC) and LC-MS/MS analysis using a hybrid LTQ Orbitrap Velos mass spectrometer. The SCX procedure does not require an HPLC system, demands little expertise, and because multiple samples can be processed in parallel, can provide a large savings of time and labor. We demonstrate this method in conjunction with stable isotope labeling to quantify peptides harboring >8,000 unique phosphorylation sites in yeast in 12 hours of instrument analysis time and examine the impact of enzyme choice and instrument platform. PMID:21440633

  9. Toxicity and composition profiles of solid phase extracts of oil sands process-affected water.

    PubMed

    Yue, Siqing; Ramsay, Bruce A; Wang, Jiaxi; Ramsay, Juliana

    2015-12-15

    After fractionation using sequential solid phase extraction, the presence of toxic components in oil sands process-affected water (OSPW) was detected by the Microtox® acute toxicity assay using effect-directed analysis. The composition of each fraction was determined by high-resolution electrospray ionization-Orbitrap mass spectrometry. Partial least-squares discriminant analysis (PLS-DA) was used to determine which chemical constituents in all seven fractions co-varied most strongly with toxicity. Although O2 compounds with double bond equivalence (DBE) between 3 and 9 positively correlated with toxicity, C15-C18 O2-NAs with DBE=4 (tricyclic structure), as well as C14-C17 O2-NAs with DBE=3 (bicyclic structure), were found to be most likely associated with OSPW toxicity, consistent with published toxicity studies of surrogate NAs. O4, many O3 (i.e. possibly hydroxylated O2 c-NAs) and a few O2 compounds were found to negatively correlate with toxicity. The results demonstrate the utility of the fractionation and the PLS-DA approach for evaluating composition-response relationships in a complex mixture and also contribute to a better understanding of the toxic compounds in OSPW. These findings will help to focus study on the most environmentally significant components in OSPW. PMID:26318810

  10. Solid-phase extraction of antipyrine dye for spectrophotometric determination of phenolic compounds in water.

    PubMed

    Morita, Emi; Nakamura, Eiko

    2011-01-01

    In order to determine phenolic compounds in water, we propose a method based on the reaction of phenolic compounds with 4-aminoantipyrine in the presence of peroxodisulfate at pH 10 to form antipyrine dye and the solid-phase extraction of dye with a Varian Bond Elut Plexa cartridge. Dye collected on the cartridge is eluted with acetonitrile and the absorbance is measured at 475 nm. In our experiments, recovery ratios of >90% were obtained for phenol, o-aminophenol, m-aminophenol, o-methoxyphenol, m-methoxyphenol, p-methoxyphenol, o-cresol, m-cresol, o-chlorophenol, m-chlorophenol, p-chlorophenol, 2,5-dimethylphenol, and 2,4-dichlorophenol. The calibration curve obeyed Beer's law in the range 0 - 0.30 µg ml(-1) phenol. The precision of repeated tests (n = 4) was 1.7% of the phenol solution (0.10 µg ml(-1)); the detection limit was 0.0011 µg ml(-1). Recovery tests using river water, waste water, and sewage influent gave highly satisfactory results. PMID:21558654

  11. Stability of benzalkonium surfactants on hemimicelle-based solid-phase extraction cartridges.

    PubMed

    Luque, Noelia; Merino, Francisco; Rubio, Soledad; Pérez-Bendito, Dolores

    2005-11-11

    The capability of hemimicelle-based solid-phase extraction cartridges for the preservation of organic compounds after their concentration from water samples was investigated for the first time. The approach is illustrated by studying the stability of benzalkonium homologue (C12, C14 and C16) surfactants (BAS) on monolayers of dodecyl sulphate (SDS) hemimicelles formed on alumina. The stability study included storage of cartridges at room temperature, at 4 and -20 degrees C, during a period of up to 3 months. The influence of water matrix components was also investigated from parallel experiments using spiked distilled, river and wastewater samples. Complete recovery of BAS was obtained for all storage conditions tested. Recoveries were independent on the alkyl chain length of BAS homologues and water matrix. The SPE of BAS on the SDS hemimicelles had a strong stabilizing effect for the target compounds and their analysis can be accomplished after at least 3 months without the necessity of special storage conditions for cartridges. Because of the lack of data, an additional stability study was carried out for BAS in an aqueous matrix using traditional preservation methods such as acidification (pH 2)/refrigeration, addition of formaldehyde (5%)/refrigeration, and freezing (-20 degrees C). Only combination of chemical addition (e.g. nitric acid or formaldehyde)/refrigeration was found effective to preserve BAS in the short term (e.g. for a week), then losses up to 40% were observed for these target compounds after a month. PMID:16257284

  12. Solid-phase extraction and LC-MS analysis of pyrrolizidine alkaloids in honeys.

    PubMed

    Beales, Kerrie A; Betteridge, Keith; Colegate, Steven M; Edgar, John A

    2004-10-20

    Strong-cation-exchange, solid-phase extraction of pyrrolizidine alkaloids and their N-oxides from honey samples was followed by reduction of the N-oxides and subsequent analysis of total pyrrolizidine alkaloids using high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry. A limited survey of 63 preprocessing samples of honey, purposefully biased toward honeys attributed to floral sources known to produce pyrrolizidine alkaloids, demonstrated levels of pyrrolizidine alkaloids up to approximately 2000 parts per billion (ppb) in a sample attributed to Echium plantagineum. Up to 800 ppb pyrrolizidine alkaloids was detected in some honeys not attributed by the collector to any pyrrolizidine alkaloid-producing floral source. No pyrrolizidine alkaloids were detected in approximately 30% of the samples in this limited study, while some honeys showed the copresence of pyrrolizidine alkaloids from multiple floral sources such as E. plantagineum and Heliotropium europaeum. In addition, retail samples of blended honeys (with no labeling to suggest that pyrrolizidine alkaloid-producing floral sources were used in the blends) have been shown to contain up to approximately 250 ppb pyrrolizidine alkaloids. PMID:15479038

  13. Determination of rhodamine B in soft drink, waste water and lipstick samples after solid phase extraction.

    PubMed

    Soylak, Mustafa; Unsal, Yunus Emre; Yilmaz, Erkan; Tuzen, Mustafa

    2011-08-01

    A new solid phase extraction method is described for sensitive and selective determination of trace levels of rhodamine B in soft drink, food and industrial waste water samples. The method is based on the adsorption of rhodamine B on the Sepabeads SP 70 resin and its elution with 5 mL of acetonitrile in a mini chromatographic column. Rhodamine B was determined by using UV visible spectrophotometry at 556 nm. The effects of different parameters such as pH, amount of rhodamine B, flow rates of sample and eluent solutions, resin amount, and sample volume were investigated. The influences of some alkali, alkali earth and transition metals on the recoveries of rhodamine B were investigated. The preconcentration factor was found 40. The detection limit based on three times the standard deviation of the reagent blank for rhodamine B was 3.14 μg L⁻¹. The relative standard deviations of the procedure were found as 5% in 1×10⁻⁵ mol L⁻¹ rhodamine B. The presented procedure was successfully applied to real samples including soft drink, food and industrial waste water and lipstick samples. PMID:21570440

  14. Isolation of tetracyclines in milk using a solid-phase extracting column and water eluent.

    PubMed

    Furusawa, Naoto

    2003-01-01

    An isolating method using a solid-phase extraction (SPE) ISOLUTE(R) C8 endcapped syringe-column for routine monitoring of residual tetracyclines (TCs) (oxytetracycline (OTC), tetracycline (TC), chlortetracycline (CTC), and doxycycline (DC)) in cow's milk is presented. In the simplest and most environmentally harmless method, milk samples could be applied directly to the SPE column, following which all TCs were eluted with water. No organic solvents were used at all. The purified sample was injected into a high-performance liquid chromatography (HPLC) with a photo-diode array detector (PDAD). For the HPLC determination/identification, a LiChrospher(R) 100 RP-8 endcapped column and a mobile phase of acetonitrile -7% (v v(-1)) acetic acid solution (in water) (35:65, v v(-1)) with a PDAD was used. The total time required for the analysis of one sample was <40 min. Average recoveries (spiked 0.1-1.0 mug ml(-1) each drug) and their standard deviations were >80 and <5%, respectively. PMID:18968895

  15. Bio-inspired solid phase extraction sorbent material for cocaine: a cross reactivity study.

    PubMed

    Montesano, Camilla; Sergi, Manuel; Perez, German; Curini, Roberta; Compagnone, Dario; Mascini, Marcello

    2014-12-01

    The binding specificity of a bio-inspired hexapeptide (QHWWDW) versus cocaine and four other drugs such as 3,4-methylenedioxy-N-methylamphetamine (MDMA), 3,4-methylenedioxy-N-ethylamphetamine (MDEA), phencyclidine and morphine was computationally studied and then experimentally confirmed in solid phase extraction (SPE) followed by liquid chromatography-mass spectrometry (LC/MS) detection. In simulation, the hexapeptide-drug complexes were docked with different scoring functions and considering pH chemical environment. In experimental, the cross reactivity of the selected hexapeptide was tested as SPE sorbent versus cocaine and other four drugs using buffer solutions at pH 4 and 7. Significant differences in specific retention were found between cocaine (97% of recovery) and both morphine (45% of recovery) and phencyclidine (60% of recovery), but less for ecstasies (average recovery 69%). In agreement with docking simulation, the hexapeptide showed the highest recovery with best specificity versus cocaine at pH 7 with an experimentally binding constant of 2.9 × 10(6)M(-1). The bio-inspired sorbent material analytical performances were compared with a commercial reversed phase cartridge confirming the hexapeptide specificity to cocaine and validating simulated data. PMID:25159425

  16. Syringe-cartridge solid-phase extraction method for patulin in apple juice.

    PubMed

    Eisele, Thomas A; Gibson, Midori Z

    2003-01-01

    A syringe-cartridge solid-phase extraction (SPE) method was developed for determination of patulin in apple juice. A 2.5 mL portion of test sample was passed through a conditioned macroporous SPE cartridge and washed with 2 mL 1% sodium bicarbonate followed by 2 mL 1% acetic acid. Patulin was eluted with 1 mL 10% ethyl acetate in ethyl ether and determined by reversed-phase liquid chromatography using a mobile phase consisting of 81% acetonitrile, 9% water, and 10% 0.05M potassium phosphate buffer, pH 2.4. Recoveries averaged 92% and the relative standard deviation was 8.0% in test samples spiked with 50 ng/mL patulin. The method appears to be applicable for monitoring apple juice samples to meet the U.S. Food and Drug Administration compliance action level of 50 microg/kg in an industrial quality assurance laboratory environment. PMID:14979697

  17. [Preparation and application of solid phase extraction packing of zirconia microsphere coated with sulfonated crosslinked polystyrene].

    PubMed

    Shen, Shuchang; Liu, Yuhui; Xiao, Xiaoxing

    2013-08-01

    Zirconia microsphere was prepared by polymerization-induced colloid aggregation (PICA) method and carbon-carbon double bond was grafted onto its surface by titanic acid ester coupling reagent. Poly(styrene-divinylbenzene) was synthesized by free radical polymerization by using styrene, divinylbenzene and carbon-carbon double bond on the microsphere surface in solution system, so the polymer was coated on the microsphere surface. After the benzene ring of the polymer was sulfonated, the cation exchange packing for solid phase extraction (SPE) was obtained. The material was characterized by Fourier transform infrared spectroscopy, scanning electron microscope and X-ray energy dispersive spectroscopy. Three herbicides of mesotrione, atrazine and acetochlor in water were determined by the SPE cartridge coupled with high performance liquid chromatography (HPLC). In the range of 0.5 - 3.0 mg/L, the relationships between the peak areas and mass concentrations of mesotrione, atrazine and acetochlor were linear with the correlation coefficients of 0.9936, 0.9925, 0.9919, respectively. The limits of detection were 5.41, 6.72 and 13.4 microg/L for mesotrione, atrazine and acetochlor, respectively. The results showed that the zirconium dioxide microspheres coated with polymer have diameters in the range of about 6 to 8 microm, the SPE cartridges of which have high adsorption rate for the targets. PMID:24369611

  18. Measurement of associations of pharmaceuticals with dissolved humic substances using solid phase extraction.

    PubMed

    Ding, Yunjie; Teppen, Brian J; Boyd, Stephen A; Li, Hui

    2013-04-01

    An innovative method was developed to determine association of carbadox, lincomycin and tetracycline with dissolved humic acids using solid phase extraction (SPE). Dissolved organic matter (DOM) and DOM-bound pharmaceuticals passed through the SPE cartridge while the cartridge retained freely dissolved pharmaceuticals from water. This method was validated by comparison with the results measured using the common equilibrium dialysis technique. For the SPE method pharmaceutical interaction with DOM required ∼30h to approach the equilibration, whereas 50-120h was needed for the equilibrium dialysis technique. The uneven distributions of freely membrane-penetrating pharmaceuticals and protons inside vs. outside of the dialysis cell due to the Donnan effect resulted in overestimates of pharmaceutical affinity with DOM for the equilibrium dialysis method. The SPE technique eliminates the Donnan effect, and demonstrates itself as a more efficient, less laborious and more accurate method. The measured binding coefficients with DOM followed the order of carbadox

  19. Chromium speciation in environmental samples by solid phase extraction on Chromosorb 108.

    PubMed

    Tuzen, Mustafa; Soylak, Mustafa

    2006-02-28

    In the present work, a solid phase extraction system has been proposed for speciation of Cr(III) and Cr(VI) in the real samples. The procedure based on the adsorption of chromium(III) as dithizonate chelate on the Chromosorb 108 resin. After reduction of Cr(VI) by concentrated H2SO4 and ethanol, the system was applied to the total chromium. Cr(VI) was calculated as the difference between the total Cr content and the Cr(III) content. The influences of the analytical parameters including pH of the aqueous solution, amounts of dithizone, eluent type, sample volume and flow rates of the sample and eluent solution were investigated. No considerable interferences have been observed from other investigated anions and cations on the chromium speciation. The adsorption capacity of sorbent was 4.50 mg/g Cr(III). The detection limit of Cr(III) is 0.75 microg/L. The proposed method was applied to the speciation of chromium in environmental samples including natural waters and total chromium preconcentration in microwave digested Turkish tobacco, coffee and soil samples with satisfactory results. In order to verify the accuracy of the method, two certified reference materials (NIST SRM 1573a Tomato Leaves and RTC-CRM 025-050 Metals on Soil) were analyzed and the results obtained were in good agreement with the certified values. The relative errors and relative standard deviations were below 5% and 9%, respectively. PMID:16236441

  20. COMPARING THE SOLID PHASE AND SALINE EXTRACT MICROTOX(R) ASSAYS FOR TWO PAH CONTAMINATED SOILS

    EPA Science Inventory

    The performance of remedial treatments is typically evaluated by measuring the concentration of specific chemicals. By adding toxicity bioassays to treatment evaluations, a fuller understanding of treatment performance is obtained. The solid phase Microtox assay is one potenti...

  1. DETERMINATION OF CHLOROETHENES IN ENVIRONMENTAL BIOLOGICAL SAMPLES USING GAS CHROMATOGRAPHY COUPLED WITH SOLID PHASE MICRO EXTRACTION

    EPA Science Inventory

    An analytical method has been developed to determine the chloroethene series, tetrachloroethene (PCE), trichloroethene (TCE),cisdichloroethene (cis-DCE) andtransdichloroethene (trans-DCE) in environmental biotreatment studies using gas chromatography coupled with a solid phase mi...

  2. Microwave-Assisted Extraction Followed by Solid-Phase Extraction for the Chromatographic Analysis of Alkaloids in Stephania cepharantha.

    PubMed

    Liu, Ying; Xie, Daotao; Kang, Yun; Wang, Yaqin; Yang, Ping; Guo, Jixian; Huang, Jianming

    2016-04-01

    A procedure involving microwave-assisted extraction (MAE) followed by solid-phase extraction (SPE) was established for the extraction and purification of three bisbenzylisoquinoline alkaloids from Stephania cepharantha, and a reversed-phase high-performance liquid chromatography (HPLC) method was developed for the quantification of the target alkaloids. Chromatographic separation was achieved on a Phenomenex Luna Phenyl-Hexyl column. Prior to the HPLC analysis, the alkaloids were rapidly extracted by an optimized MAE process using 0.01 mol/L hydrochloric acid as the solvent. The MAE extract was subsequently purified by SPE using a cation-exchange polymeric cartridge. The MAE-SPE procedure extracted the three alkaloids with satisfactory recoveries ranging from 100.44 to 102.12%. In comparison with the MAE, Soxhlet and ultrasonic-assisted extractions, the proposed MAE-SPE method showed satisfactory cleanup efficiency. Thus, the validated MAE-SPE-HPLC method is specific, accurate and applicable to the determination of alkaloids in S. cepharantha. PMID:26759486

  3. Improved solid phase extraction of ferulate phytosterol esters from corn distiller's dried grain extract

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We recently reported on the retention of valuable phytochemicals such as ferulate phytosterol esters (FPE), tocopherols (T), and tocotrienols (T3) in solvent and CO2 extracts of distillers dried grains (DDG). However, the extraction and purification of these phytochemicals, especially FPE, from the...

  4. Membrane solid-phase extraction: Field application for isolation of polycyclic aromatic hydrocarbons from water samples

    SciTech Connect

    Furlong, E.T.; Koleis, J.C.; Gates, P.M.

    1995-12-31

    Solid-phase extraction (SPE) membranes (M-SPE) were used to isolate microgram-per-liter to nanogram-per-liter quantities of polycyclic aromatic hydrocarbons (PAH) in 4- to 8-liter ground-water samples from a crude-oil-contaminated ground-water site near Bemidji, Minnesota. The M-SPE method was evaluated (1) under laboratory conditions using reagent water fortified with individual PAH at 1.23 micrograms per liter, and (2) at the Bemidji site. At the site, ground-water samples were processed and PAH isolated using a M-SPE system connected directly to the well pump. Following sample isolation, all M-SPE samples were extracted using dichloromethane and analyzed by gas chromatography-mass spectrometry with selected-ion monitoring. Operationally, the M-SPE method provided a simple means to isolate PAH on site at the wellhead, particularly for anoxic water samples. Acceptable recoveries, ranging from 56 to over 100 percent, were observed for lower molecular weight PAH (naphthalene to pyrene) using the M-SPE method. Recoveries using M-SPE were somewhat lower, but reproducible, for higher molecular weight PAH (chrysene to benzo[ghi]perylene), ranging from 18 to 56 percent. M-SPE provides the capability to collect and field isolate PAH from a sufficiently large number of samples to identify environmental chemical processes occurring at individual compound concentrations of 50 to 1,200 nanograms per liter. Using M-SPE, the potential for facilitated transport of PAH by in situ-derived dissolved organic carbon (DOC) was evaluated at the site. Plots comparing DOC and PAH concentrations indicate that PAH concentrations increase exponentially with linear increases in DOC concentrations.

  5. Magnetic micro-solid-phase-extraction of polycyclic aromatic hydrocarbons in water.

    PubMed

    Naing, Nyi Nyi; Yau Li, Sam Fong; Lee, Hian Kee

    2016-04-01

    A novel sorbent, magnetic chitosan functionalized graphene oxide (MCFG) was synthesized and used in the micro-solid-phase-extraction (μ-SPE) and gas chromatography-mass spectrometric (GC-MS) analysis of polycyclic aromatic hydrocarbons (PAHs) from water. Through the use of the magnetic sorbent, the μ-SPE device also functioned as a stir bar during extraction. Three types of MCFG were prepared using glutaraldehyde cross-linked chitosan and graphene oxide with different amounts of magnetic nanoparticles (Fe3O4) (0.05g, 0.07g and 0.1g). The material was characterized using Fourier transform infrared spectroscopy and field emission scanning electron microscopy. Parameters affecting the extraction such as the type of sorbent, extraction and desorption times, volume of sample solution and type of desorption solvent were optimized. Under the most favourable conditions, the highest extraction was obtained by using the composite prepared with 0.1g of Fe3O4. For the latter material as sorbent, the linearity of the analytes was in the range of 0.01 and 100μgL(-1) for naphthalene, fluoranthene and pyrene while acenaphthylene and phenanthrene exhibited linearity in the range of 0.05 and 100μgL(-1). For fluorene and anthracene, the linearity range was from 0.01 to 50μgL(-1). The coefficients of determination (r(2)) associated with the above linear ranges were higher than 0.987. The limits of detection from GC-MS analysis of the seven PAHs were in the range 0.2-1.8ngL(-1); limits of quantification were between 0.8 and 5.9ngL(-1) while the relative standard deviations (RSDs) varied from 2.1 to 8.2%. The recoveries of the method for the compounds at spiking levels of 1 and 5μgL(-1) were in the range 67.5-106.9% with RSDs below 15%. The enrichment factors were found to be in between 67 and 302. The developed method afforded an interesting and innovative approach using MCFG as an efficient and promising sorbent. PMID:26931424

  6. Ionic liquid-based foam flotation followed by solid phase extraction to determine triazine herbicides in corn.

    PubMed

    Zhang, Liyuan; Wang, Zhibing; Li, Na; Yu, Aimin; Zhang, Hanqi

    2014-05-01

    Ionic liquid-based foam flotation followed by solid phase extraction was developed for extraction of eight triazine herbicides, including cyanazine, metribuzin, desmetryn, secbumeton, terbumeton, terbuthylazine, dimethametryn and dipropetryn in corn samples. When the extraction was completed, the analytes were separated from the sample matrix by foam flotation and introduced into the solid phase extraction cartridge. The separation and concentration of target analytes were performed simultaneously. The analytes eluted from the solid phase extraction cartridge were determined by high performance liquid chromatography. The effects of experimental parameters of extraction and flotation were examined. Under the optimized experimental conditions, a good linearity was obtained in the range of 2.50-150 µg/kg. The detection limits of the triazine herbicides were in the range of 0.74-1.62 µg/kg. The present method was successfully applied to the analysis of corn samples. The recoveries ranged from 85.9% to 104.0% and the relative standard deviations were lower than 5.6%. PMID:24720960

  7. Class-specific molecularly imprinted polymers for the selective extraction and determination of sulfonylurea herbicides in maize samples by high-performance liquid chromatography-tandem mass spectrometry.

    PubMed

    She, Yong-Xin; Cao, Wei-Qiang; Shi, Xiao-Mei; Lv, Xiao-Ling; Liu, Jia-Jia; Wang, Rong-Yan; Jin, Fen; Wang, Jing; Xiao, Hang

    2010-08-01

    A novel method based on the molecularly imprinted solid-phase extraction (MISPE) procedure has been developed for the simultaneous determination of concentrations of sulfonylurea herbicides such as chlorsulfuron (CS), monosulfuron (MNS), and thifensulfuron methyl (TFM) in maize samples by liquid chromatography-tandem quadrupole mass spectrometry (LC-MS/MS). The molecularly imprinted polymer (MIP) for sulfonylurea herbicides was synthesized by precipitation polymerization using chlorsulfuron as the template molecule, 2-(diethylamino)ethyl methacrylate (DEAMA) as the functional monomer, and trimethylolpropane trimethacrylate (TRIM) as the cross-linker. The selectivities of the chlorsulfuron template and its analogs on the molecularly imprinted polymer were evaluated by high-performance liquid chromatography (HPLC). The extraction and purification procedures for the solid-phase extraction (SPE) cartridge with a molecularly imprinted polymer as the adsorbent for the selected sulfonylurea herbicides were then established. A molecularly imprinted solid-phase extraction method followed by high-performance liquid chromatography-tandem mass spectrometry for the determination of chlorsulfuron, monosulfuron, and thifensulfuron methyl was also established. The mean recoveries of these compounds in maize were in the range 75-110% and the limits of detection (LOD) of chlorsulfuron, monosulfuron, and thifensulfuron methyl were 0.02, 0.75, and 1.45 microg kg(-1), respectively. It was demonstrated that the MISPE-HPLC-MS/MS method could be applied to the determination of chlorsulfuron, monosulfuron, and thifensulfuron methyl in maize samples. PMID:20598653

  8. Colorimetric Solid Phase Extraction (CSPE): Using Color to Monitor Spacecraft Water Quality

    NASA Technical Reports Server (NTRS)

    Gazda, Daniel B.; Nolan, Daniel J.; Rutz, Jeffrey A.; Schultz, John R.; Siperko, Lorraine M.; Porter, Marc D.; Lipert, Robert J.; Flint, Stephanie M.; McCoy, J. Torin

    2010-01-01

    In August 2009, an experimental water quality monitoring kit based on Colorimetric Solid Phase Extraction (CSPE) technology was delivered to the International Space Station (ISS). The kit, called the Colorimetric Water Quality Monitoring Kit (CWQMK), was launched as a Station Development Test Objective (SDTO) experiment to evaluate the suitability of CSPE technology for routine use monitoring water quality on the ISS. CSPE is a sorption-spectrophotometric technique that combines colorimetric reagents, solid-phase extraction, and diffuse reflectance spectroscopy to quantify trace analytes in water samples. In CSPE, a known volume of sample is metered through a membrane disk that has been impregnated with an analyte-specific colorimetric reagent and any additives required to optimize the formation of the analyte-reagent complex. As the sample flows through the membrane disk, the target analyte is selectively extracted, concentrated, and complexed. Formation of the analyte-reagent complex causes a detectable change in the color of the membrane disk that is proportional to the amount of analyte present in the sample. The analyte is then quantified by measuring the color of the membrane disk surface using a hand-held diffuse reflectance spectrophotometer (DRS). The CWQMK provides the capability to measure the ionic silver (Ag +) and molecular iodine (I2) in water samples on-orbit. These analytes were selected for the evaluation of CSPE technology because they are the biocides used in the potable water storage and distribution systems on the ISS. Biocides are added to the potable water systems on spacecraft to inhibit microbial growth. On the United States (US) segment of the ISS molecular iodine serves as the biocide, while the Russian space agency utilizes silver as a biocide in their systems. In both cases, the biocides must be maintained at a level sufficient to control bacterial growth, but low enough to avoid any negative effects on crew health. For example, the

  9. CLEANUP OF ENVIRONMENTAL SAMPLE EXTRACTS USING FLORISIL SOLID-PHASE EXTRACTION CARTRIDGES

    EPA Science Inventory

    Disposable cartridges containing 1 g of Florisil are investigated for cleanup of extracts obtained from various environmental natrices. lution patterns and recoveries are determined for 22 chlorinated hydrocarbons and 16 phthalate esters in the presence of interferents such as co...

  10. [Determination of vitamin D in calcium fortified foods using solid-phase extraction-high performuance liquid chromatography].

    PubMed

    Zhao, Rong; Xue, Ying; Wu, Guohua; Zhao, Haiyan; Luo, Rencai

    2008-01-01

    A method for the determination of vitamin D in calcium fortified foods using solid-phase extraction-high performance liquid chromatography has been developed. The Chromabond XTR solid-phase extraction column (14,500 mg, 70 mL) was used to extract and clean-up the sample. The calibration curve of vitamin D showed good linearity in the range of 0.1-100.0 microg/mL with correlation coefficient of 0.999. The limit of qualification was 0.01 microg/g and the limit of quantification was 0.03 microg/g. The average recoveries at three spiking levels were 106.2%, 99.5%, 100.1%, and the relative standard deviations were lower than 10%. PMID:18438037

  11. Liquid-Liquid Extraction and Solid Phase Extraction for Urinary Organic Acids: A Comparative Study from a Resource Constraint Setting.

    PubMed

    Kumari, Chandrawati; Varughese, Bijo; Ramji, Siddarth; Kapoor, Seema

    2016-10-01

    Pre analytical process of extraction for accurate detection of organic acids is a crucial step in diagnosis of organic acidemias by GCMS analysis. This process is accomplished either by solid phase extraction (SPE) or by liquid-liquid extraction (LLE). Both extraction procedures are used in different metabolic laboratories all over the world. In this study we compared these two extraction procedures in respect of precision, accuracy, percent recovery of metabolites, number of metabolites isolated, time and cost in a resource constraint setup. We observed that the mean recovery from SPE was 84.1 % and by LLE it was 77.4 % (p value <0.05). Moreover, the average number of metabolites isolated by SPE and LLE was 161.8 ± 18.6 and 140.1 ± 20.4 respectively. The processing cost of LLE was economical. In a cost constraint setting using LLE may be the practical option if used for organic acid analysis. PMID:27605738

  12. Direct Sampling and Analysis from Solid Phase Extraction Cards using an Automated Liquid Extraction Surface Analysis Nanoelectrospray Mass Spectrometry System

    SciTech Connect

    Walworth, Matthew J; ElNaggar, Mariam S; Stankovich, Joseph J; WitkowskiII, Charles E.; Norris, Jeremy L; Van Berkel, Gary J

    2011-01-01

    Direct liquid extraction based surface sampling, a technique previously demonstrated with continuous flow and autonomous pipette liquid microjunction surface sampling probes, has recently been implemented as the Liquid Extraction Surface Analysis (LESA) mode on the commercially available Advion NanoMate chip-based infusion nanoelectrospray ionization system. In the present paper, the LESA mode was applied to the analysis of 96-well format custom solid phase extraction (SPE) cards, with each well consisting of either a 1 or 2 mm diameter monolithic hydrophobic stationary phase. These substrate wells were conditioned, loaded with either single or multi-component aqueous mixtures, and read out using the LESA mode of a TriVersa NanoMate or a Nanomate 100 coupled to an ABI/Sciex 4000QTRAPTM hybrid triple quadrupole/linear ion trap mass spectrometer and a Thermo LTQ XL linear ion trap mass spectrometer. Extraction conditions, including extraction/nanoESI solvent composition, volume, and dwell times, were optimized in the analysis of targeted compounds. Limit of detection and quantitation as well as analysis reproducibility figures of merit were measured. Calibration data was obtained for propranolol using a deuterated internal standard which demonstrated linearity and reproducibility. A 10x increase in signal and cleanup of micromolar Angiotensin II from a concentrated salt solution was demonstrated. Additionally, a multicomponent herbicide mixture at ppb concentration levels was analyzed using MS3 spectra for compound identification in the presence of isobaric interferences.

  13. Optimization of in-line fritless solid-phase extraction for capillary electrophoresis-mass spectrometry.

    PubMed

    Tak, Yvonne H; Toraño, Javier Sastre; Somsen, Govert W; de Jong, Gerhardus J

    2012-12-01

    In this study, in-line frit-free solid-phase extraction (SPE) has been studied for the preconcentration of analytes prior to analysis by capillary electrophoresis-mass spectrometry (CE-MS). The mixed-mode sorbent Oasis HLB was selected for the trapping of compounds of different polarity. Using 2-ethylidene-1,5-dimethyl-3,3-diphenylpirrolidine (EDDP), dihydrocodeine and codeine as test compounds, SPE parameters such as the pH of the sample and composition of the washing and elution solvent were optimized. Trapping of the analytes was optimal at pH 8.0 or higher. For efficient elution of the SPE micro column, 85% of methanol in water with 2% (v/v) acetic acid was used, which also prevented current break down in subsequent CE analysis. CE resolution of the test compounds was highest for background electrolytes (BGEs) with a pH above 8. For optimal analysis, samples were 1:1 diluted with carbonate buffer (1M, pH 8.0) prior to analysis, BGE was 60mM ammonium acetate buffer (pH 10.0), and the injected sample volume was 60 μl (i.e., 30 capillary volumes). Good recoveries were found: 101% for EDDP, 88% for codeine and 90% for dihydrocodeine. Intraday RSDs for migration time and peak areas were below 0.56% and 15%, respectively. Peak widths at half height obtained with SPE-CE-MS were 12s for EDDP, 3.7s for dihydrocodeine and 7.4s for codeine, and were comparable to those for CE-MS. LODs were 0.22 pg/ml for EDDP, 2.1 pg/ml for dihydrocodeine and 24 pg/ml for codeine. It is concluded that the applied fritless in-line preconcentration construct proved to be highly useful for improving the sensitivity of CE while maintaining separation. PMID:22959866

  14. Phototoxicity identification by solid phase extraction and photoinduced toxicity to Daphnia magna.

    PubMed

    Wernersson, A; Dave, G

    1997-04-01

    The photoinduced toxicity of several environmental pollutants (some Polycyclic Aromatic Hydrocarbons [PAHs]) is a potential threat to aquatic organisms. To identify the cause/s of photoinduced toxicity of a sample, it is not sufficient to simply analyze the content of some known phototoxic compounds; so far too few substances of environmental concern have ever been tested for their photoinduced toxicity. The PAHs as well as other known phototoxic compounds are hydrophobic and are expected to bind to C18 columns. The use of Solid Phase Extraction (SPE) is typically part of the procedure identifying any primary nonpolar toxicant/s, and adding phototoxicity tests to these manipulations would not substantially increase the workload. In this study, therefore, the difference in acute toxicity to Daphnia magna before and after 2 h of UV irradiation was determined for six PAHs. The ratio between EC50 values before and after UV irradiation ranged from 4.6 (for benzo-a-pyrene) to >244 (for 3, 4-benzofluoranthene), demonstrating that the UV enhances the PAH-toxicity. A further characterization technique using binding to Sep-Pak SPE C18 columns and recovery with methanol as an eluting agent was then tested in combination with UV irradiation. The mean recovered UV induced toxicity after binding and elution of the six PAHs was 119% according to the phototoxicity tests made. A linear relationship, between the log10 Kow values for the PAHs and the log10 for the concentration of methanol at peak elution was found. The combined use of C18 column separation and UV activation may, therefore, be used in toxicity identification evaluations (TIE) of organic phototoxic compounds. PMID:9096075

  15. A solid phase extraction procedure for determination of triazine herbicides and polar metabolites in natural waters

    SciTech Connect

    Young, M.S.

    1996-11-01

    Atrazine and related triazine herbicides are used in great quantities throughout the world for pre-emergence weed control. In the central United States, for example, millions of kilograms of triazines are applied each year. In areas of heavy usage, surface water supplies are often affected by runoff of these substances and their transformation products. Therefore, a number of these compounds are routinely monitored in drinking water in the United States, particularly in agricultural areas such as the Mississippi river valley. There is also significant interest regarding the fate and transport of the triazine herbicides in the natural environment. In Europe, where groundwater is utilized for a high proportion of drinking water supplies, the EC has established more stringent limits than has the US EPA. Currently, the US limit is 3 {mu}g/L for atrazine; the European limit is 0.1 {mu}g/L for atrazine or any individual regulated pesticide, and 0.5 {mu}g/L for the sum of all pesticides. Because groundwater levels in agricultural areas were consistently above this limit, Germany banned the use of Atrazine in 1991, and has recommended banning the use of this herbicide throughout the European Community (EC). Clearly, a rugged method for determination of the triazine herbicides is desirable with detection limits in the part per trillion range. Because direct determination at these levels is not usually possible, sample enrichment techniques, such as solid phase extraction (SPE), must be employed. In this study, Porapak RDX Sep-Pak{reg_sign} cartridges were used for trace enrichment of triazines and metabolites.

  16. A new method for thioarsenate preservation in iron-rich waters by solid phase extraction.

    PubMed

    Ullrich, Maria K; Misiari, Valentina; Planer-Friedrich, Britta

    2016-10-01

    In order to preserve iron-rich samples for arsenic speciation analysis, mineral acids or EDTA are typically added to prevent oxidation and precipitation of iron. However, when sulfide is present, and thioarsenates ([HAs(V)S(-II)nO4-n](2-), n = 1-4) can form, these methods are unsuitable due to arsenic sulfide precipitation or artifact speciation changes. Here, a new method based on separating the anionic arsenic species from cationic iron in the presence of sulfide via solid phase extraction (SPE) has been investigated. Synthetic solutions containing arsenite, arsenate, monothioarsenate, and trithioarsenate were passed through the anion-exchange resin AG2-X8, after which the resin was washed, eluted, and speciation of each step analyzed by IC-ICP-MS. Retention on the resin of 96.8 ± 0.2%, 98.8 ± 0.2%, and 99.6 ± 0.3% was found for arsenate, monothioarsenate, and trithioarsenate, respectively. Cationic iron (90 μM Fe(II)) was not retained (0.4 ± 0.2%). Uncharged arsenite passed through the resin in the absence of sulfide, while 47.3% of arsenite were retained at tenfold sulfide excess via thiol groups binding to the organic resin structure. Elution with 3 × 15 mL of 0.5 M salicylate, including a soak time, resulted in quantitative recovery of all retained species. Stability of the retained species on the resin was tested with iron-rich, natural waters from a Czech mineral spring. Arsenate, monothioarsenate, dithioarsenate, and trithioarsenate were successfully separated from iron and recovered after 6 d. Thus, SPE presents a viable answer to the problem of preserving arsenic in the presence of both iron and sulfide. PMID:27423048

  17. Development of an integrated microfluidic solid-phase extraction and electrophoresis device.

    PubMed

    Kumar, Suresh; Sahore, Vishal; Rogers, Chad I; Woolley, Adam T

    2016-03-01

    This study focuses on the design and fabrication of a microfluidic platform that integrates solid-phase extraction (SPE) and microchip electrophoresis (μCE) on a single device. The integrated chip is a multi-layer structure consisting of polydimethylsiloxane valves with a peristaltic pump, and a porous polymer monolith in a thermoplastic layer. The valves and pump are fabricated using soft lithography to enable pressure-based fluid actuation. A porous polymer monolith column is synthesized in the SPE unit using UV photopolymerization of a mixture consisting of monomer, cross-linker, photoinitiator, and porogens. The hydrophobic, porous structure of the monolith allows protein retention with good through flow. The functionality of the integrated device in terms of pressure-controlled flow, protein retention and elution, on-chip enrichment, and separation is evaluated using ferritin (Fer). Fluorescently labeled Fer is enriched ∼80-fold on a reversed-phase monolith from an initial concentration of 100 nM. A five-valve peristaltic pump produces higher flow rates and a narrower Fer elution peak than a three-valve pump operated under similar conditions. Moreover, the preconcentration capability of the SPE unit is demonstrated through μCE of enriched Fer and two model peptides in the integrated system. FA, GGYR, and Fer are concentrated 4-, 12-, and 50-fold, respectively. The loading capacity of the polymer monolith is 56 fmol (25 ng) for Fer. This device lays the foundation for integrated systems that can be used to analyze various disease biomarkers. PMID:26820409

  18. EVALUATION OF SAMPLE EXTRACT CLEANUP USING SOLID-PHASE EXTRACTION CARTRIDGES

    EPA Science Inventory

    Fractionation and cleanup of sample extracts prior to instrumental analysis is usually accomplished by column chromatography, gel permeation chromatography, or acid-base partitioning. n this report, the results of a study are described in which we investigated the application of ...

  19. Novel molecularly imprinted magnetic nanoparticles for the selective extraction of protoberberine alkaloids in herbs and rat plasma.

    PubMed

    Meng, Jiawei; Zhang, Wenpeng; Bao, Tao; Chen, Zilin

    2015-06-01

    In this work, a novel magnetic nanomaterial functionalized with a molecularly imprinted polymer was prepared for the extraction of protoberberine alkaloids. Molecularly imprinted polymers were made on the surface of Fe3 O4 nanoparticles by using berberine as template, acetonitrile/water as porogen, acrylamide as functional monomer and ethylene glycol dimethacrylate as cross-linker. The optimized molar ratio of template/functional monomer was 1:7. The polymeric magnetic nanoparticles were characterized by transmission electron microscopy and Fourier transform infrared spectroscopy. The stability and adsorption capacity of the molecularly imprinted polymers were investigated. The molecularly imprinted polymers were used as a selective sorbent for the magnetic molecularly imprinted solid-phase extraction and determination of jatrorrhizine, palmatine, and berberine. Extraction parameters were studied including loading pH, sample volume, stirring speed, and extraction time. Finally, a magnetic molecularly imprinted solid-phase extraction coupled to high-performance liquid chromatography method was developed. Under the optimized conditions, the method showed good linear range of 0.1-150 ng/mL for berberine and 0.1-100 ng/mL for jatrorrhizine and palmatine. The limit of detection was 0.01 ng/mL for berberine and 0.02 ng/mL for jatrorrhizine and palmatine. The proposed method has been applied to determine protoberberine alkaloids in Cortex phellodendri and rat plasma samples. The recoveries ranged from 87.33-102.43%, with relative standard deviation less than 4.54% in Cortex phellodendri and from 102.22-111.15% with relative standard deviation less than 4.59% in plasma. PMID:25832420

  20. Separation and concentration of sulfonylurea herbicides in milk by ionic-liquid-based foam flotation solid-phase extraction.

    PubMed

    Zhang, Liyuan; Cao, Bocheng; Yao, Di; Yu, Runzhong; Yu, Changqing; Zhang, Hanqi; Yu, Aimin

    2015-05-01

    The ultrasound-assisted ionic liquid foam flotation solid-phase extraction of sulfonylurea herbicides in milk was developed and validated. The proteins and lipids were isolated from the sample matrix by adding salt and adjusting the pH value. The target analytes eluted from the solid-phase extraction cartridge were determined by high-performance liquid chromatography. Some experimental parameters, including the pH value of sample solution, amount of NaCl, ionic liquid type, extraction time, flow rate of carrier gas, flotation time, and solid-phase extraction cartridge type were investigated and optimized. Under the optimized experimental conditions, the limits of detection for metsulfuron, pyrazosulfuron, chlorimuron-ethyl, and nicosulfuron were 1.3, 0.6, 0.7, and 1.1 μg/L, respectively. When the present method was applied to the analysis of milk samples the recoveries of the analytes ranged from 84.3 to 105.2% and relative standard deviations were >5.7%. PMID:25727190

  1. Chromium speciation by solid phase extraction on Dowex M 4195 chelating resin and determination by atomic absorption spectrometry.

    PubMed

    Saygi, Kadriye Ozlem; Tuzen, Mustafa; Soylak, Mustafa; Elci, Latif

    2008-05-30

    A solid phase extraction procedure has been established for chromium speciation in natural water samples prior to determination by atomic absorption spectrometry. The procedure is based on the solid phase extraction of the Cr(VI)- Dowex M 4195 chelating resin. After oxidation of Cr(III) to Cr(VI) by using H2O2, the presented method was applied to the determination of the total chromium. The level of Cr(III) is calculated by difference of total chromium and Cr(VI) levels. The procedure was optimized for some analytical parameters including pH, eluent type, flow rates of sample and eluent, matrix effects, etc. The presented method was applied for the speciation of chromium in natural water samples with satisfactory results (recoveries >95%, RSDs <10%). In the determinations of chromium species, flame atomic absorption spectrometer was used. The results were checked by using NIST SRM 2711 Montana soil and GBW 07603 Bush branched and leaves. PMID:17951001

  2. On-site solid-phase extraction and application to in situ preconcentration of heavy metals in surface water.

    PubMed

    Jiao, Fang; Gao, Hong-Wen

    2013-01-01

    An on-site solid-phase extraction, consisting of the sorption, the separation and the elution function units, was designed for in situ preconcentration of heavy metals ions. The D401 resin powder was employed as sorbent to capture Pb(2+), Cu(2+), Zn(2+), Cd(2+), Co(2+), and Ni(2+), and then they desorbed with 2 mol/L nitric acid as eluent. Under the optimized conditions, these heavy metals ions in West Lake, Taihu Lake, and Yangtze River of China were captured and then determined by ICP-OES with the recovery of 92.5% to 111.5%. The on-site solid-phase extraction achieved a quick preconcentration of heavy metals to avoid the transport and storage of a large volume water sample. It is suitable for in situ monitoring of water quality in mountains, tablelands or other remote areas. PMID:22286838

  3. Chemically modified polymeric resins for high performance liquid chromatography, solid-phase extraction and organic separation by LC and GC

    SciTech Connect

    Sun, Jeffrey Jiafang.

    1991-08-06

    Polystyrene divinylbenzene resins were chemically modified by introduction of various functional groups, which included polar, non-polar, ionic and metallic groups. These chemically modified polymeric resins were used successfully for high performance liquid chromatography, solid phase extraction and some special applications in liquid and gas chromatography. The introduced functional groups offer an additional selectivity parameter for liquid chromatographic separation. The polar derivatized polymeric resins dramatically increased the recoveries of solid phase extraction, especially for polar compounds. The sulfonated polystyrene resins were used for separation of neutral and basic compounds as well as basic and weaker basic compounds. The sulfonated non-porous resin was used amine abstracter and the polymeric-mercuric resin was used as mercaptan abstracter in capillary gas chromatograph. The researches in this dissertation has shown the very promising applications of polystyrene divinylbenzene resin in chromatographic field. 58 refs., 34 figs., 28 tabs.

  4. A novel dispersive micro solid phase extraction using zein nanoparticles as the sorbent combined with headspace solid phase micro-extraction to determine chlorophenols in water and honey samples by GC-ECD.

    PubMed

    Farhadi, Khalil; Matin, Amir Abbas; Amanzadeh, Hatam; Biparva, Pourya; Tajik, Hossein; Farshid, Amir Abbas; Pirkharrati, Hossein

    2014-10-01

    This study presents a new technique, dispersive micro solid phase extraction (DMSPE) combined with headspace solid phase micro-extraction (HS-SPME) for extraction and determination of chlorophenols (CPs) in water and honey samples using a Gas Chromatography-Electron Capture Detector (GC-ECD). Zein nanoparticles were made by liquid-liquid dispersion and applied for the first time as the sorbent phase in DMSPE. In the proposed DMSPE-HS-SPME method, 1% w/v of ethanolic zein solution was added to an aqueous sample and then a dose of the in-situ generated zein nanoparticles was applied to a pre-concentration of target analytes. Thermal desorption of analytes was performed after the isolating sorbent phase, and then HS-SPME was applied for enrichment prior to introducing to gas chromatography. All the important parameters influencing efficiency of the extraction process such effects of salt, pH, sorbent concentration, temperature, sorbent solution volume in DMSPE procedure, extraction temperature, extraction time, desorption temperature and time in the HS-SPME procedure were investigated and optimized. Results showed that under optimum extraction conditions, detection limits (signal to noise ratio=3) were in the range of 0.08-0.6 ng mL(-1) and evaluations for relative standard deviations (RSDs %) were between 6.62% and 8.36%. PMID:25059191

  5. Selectivity of solid phase extraction of freshwater dissolved organic matter and its effect on ultrahigh resolution mass spectra.

    PubMed

    Raeke, Julia; Lechtenfeld, Oliver J; Wagner, Martin; Herzsprung, Peter; Reemtsma, Thorsten

    2016-07-13

    Solid phase extraction (SPE) is often used for enrichment and clean-up prior to analysis of dissolved organic matter (DOM) by electrospray ionization (ESI) coupled to ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). It is generally accepted that extraction by SPE is not quantitative with respect to carbon concentration. However, little information is available on the selectivity of different SPE sorbents and the resulting effect for the acquired DOM mass spectra. Freshwater samples were extracted by the widely used PPL, HLB and C18 sorbents and the molecular composition and size distribution of the DOM in the extracts and in the permeates was compared to the original sample. Dissolved organic carbon (DOC) recoveries ranged between 20% and 65% for the three tested SPE sorbents. Size-exclusion chromatography coupled to organic carbon detection (SEC-OCD) revealed that limited recovery by PPL and HLB was primarily due to incomplete elution of a fraction of apparent high molecular weight from the solid phase. In contrast, incomplete retention on the solid phase, mainly observed for the C18 cartridge, was attributed to a fraction of low molecular weight. The FT-ICR mass spectra of the original sample and the SPE extracts did not differ significantly in their molecular weight distribution, but they showed sorbent specific differences in the degree of oxygenation and saturation. We concluded that the selective enrichment of freshwater DOM by SPE is less critical for subsequent FT-ICR MS analysis, because those fractions that are not sufficiently recovered have comparatively small effects on the mass spectra. This was confirmed by the extraction of model compounds, showing that very polar and small molecules are poorly extracted, but also have a low response in ESI-MS. Of the three tested SPE cartridges the PPL material offered the best properties for DOM enrichment for subsequent FT-ICR MS analysis as it minimizes too strong and

  6. Design of the extraction process for terpenes and other volatiles from allspice by solid-phase microextraction and hydrodistillation.

    PubMed

    Bajer, Tomáš; Ligor, Magdalena; Ligor, Tomasz; Buszewski, Bogusław

    2016-02-01

    Methods for the separation and determination of terpenes (mono- and sesqui-) and phenylpropanoids such as eugenol and methyleugenol from samples of allspice berries have been developed. Chromatographic analyses of isolated groups of compounds were carried out by means of gas chromatography coupled with mass spectrometry. A comparison of various types of solid-phase microextraction fibers was performed. The highest yields of terpenes were extracted by polydimethylsiloxane and divinylbenzene/Carboxen/polydimethylsiloxane fibers (almost the same for these two fibers), approximately twice as much as by Carbowax/divinylbenzene fiber. The highest amounts of monoterpenes were extracted by divinylbenzene/Carboxen/polydimethylsiloxane fiber, and the highest amounts of sesquiterpenes were extracted by polydimethylsiloxane fiber. Moreover, the effect of water addition on extraction yields as well as time and temperature of extraction were tested. Aroma profiles of extracts obtained by solid-phase microextraction and essential oil obtained by hydrodistillation of allspice berries were compared. The aroma profile of the divinylbenzene/Carboxen/polydimethylsiloxane fiber extract was similar to the aroma profile of essential oil. Particular characteristics of volatile allspice matters were presented. The linear retention indices for each compound were calculated. PMID:26632088

  7. Application of the Empore solid-phase extraction membrane to the isolation of drugs from blood. I. Amiodarone and desethylamiodarone.

    PubMed

    Lensmeyer, G L; Wiebe, D A; Doran, T

    1991-05-01

    We describe the use of a new form of solid-phase material, the Empore solid-phase extraction membrane (SPEM), for therapeutic drug monitoring. We evaluated the new extraction procedure with the companion high-performance liquid chromatographic (HPLC) method for the antiarrhythmic drug amiodarone and its metabolite, desethylamiodarone, in patients' serum. Acidified serum (250 microliters) was passed through an octyl (C8) SPEM secured in an MF-1 microfilter unit. Serum proteins and potential interferences were removed with an acetonitrile:water wash, and the retained drugs eluted with HPLC mobile phase. This eluate was injected directly onto the analytical column. Both drugs averaged 85% recovery with a linear response from a lower limit of detection at 0.05 mg/L up to 6 mg/L, and between-run precision coefficients of variation ranging from 3.1 to 6.4% over the concentration range of 0.5-3.0 mg/L. We observed significant advantages of the novel SPEM over conventional liquid-liquid or large-particle size solid-phase sorbents packed in cartridges. Minimal amounts of solvents were required, elution volume was smaller, time-consuming evaporating/concentrating steps that can influence drug stability were avoided, and little throw-away material was generated. Only the small membrane was discarded. PMID:1926279

  8. Graphene-Based Materials as Solid Phase Extraction Sorbent for Trace Metal Ions, Organic Compounds, and Biological Sample Preparation.

    PubMed

    Ibrahim, Wan Aini Wan; Nodeh, Hamid Rashidi; Sanagi, Mohd Marsin

    2016-07-01

    Graphene is a new carbon-based material that is of interest in separation science. Graphene has extraordinary properties including nano size, high surface area, thermal and chemical stability, and excellent adsorption affinity to pollutants. Its adsorption mechanisms are through non-covalent interactions (π-π stacking, electrostatic interactions, and H-bonding) for organic compounds and covalent interactions for metal ions. These properties have led to graphene-based material becoming a desirable adsorbent in a popular sample preparation technique known as solid phase extraction (SPE). Numerous studies have been published on graphene applications in recent years, but few review papers have focused on its applications in analytical chemistry. This article focuses on recent preconcentration of trace elements, organic compounds, and biological species using SPE-based graphene, graphene oxide, and their modified forms. Solid phase microextraction and micro SPE (µSPE) methods based on graphene are discussed. PMID:26186420

  9. Rapid determination of the volatile components in tobacco by ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction with gas chromatography-mass spectrometry.

    PubMed

    Yang, Yanqin; Chu, Guohai; Zhou, Guojun; Jiang, Jian; Yuan, Kailong; Pan, Yuanjiang; Song, Zhiyu; Li, Zuguang; Xia, Qian; Lu, Xinbo; Xiao, Weiqiang

    2016-03-01

    An ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction was first employed to determine the volatile components in tobacco samples. The method combined the advantages of ultrasound, microwave, and headspace solid-phase microextraction. The extraction, separation, and enrichment were performed in a single step, which could greatly simplify the operation and reduce the whole pretreatment time. In the developed method, several experimental parameters, such as fiber type, ultrasound power, and irradiation time, were optimized to improve sampling efficiency. Under the optimal conditions, there were 37, 36, 34, and 36 components identified in tobacco from Guizhou, Hunan, Yunnan, and Zimbabwe, respectively, including esters, heterocycles, alkanes, ketones, terpenoids, acids, phenols, and alcohols. The compound types were roughly the same while the contents were varied from different origins due to the disparity of their growing conditions, such as soil, water, and climate. In addition, the ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction method was compared with the microwave-assisted extraction coupled to headspace solid-phase microextraction and headspace solid-phase microextraction methods. More types of volatile components were obtained by using the ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction method, moreover, the contents were high. The results indicated that the ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction technique was a simple, time-saving and highly efficient approach, which was especially suitable for analysis of the volatile components in tobacco. PMID:26833965

  10. 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

  11. Computational and experimental investigation of molecular imprinted polymers for selective extraction of dimethoate and its metabolite omethoate from olive oil.

    PubMed

    Bakas, Idriss; Oujji, Najwa Ben; Moczko, Ewa; Istamboulie, Georges; Piletsky, Sergey; Piletska, Elena; Ait-Addi, Elhabib; Ait-Ichou, Ihya; Noguer, Thierry; Rouillon, Régis

    2013-01-25

    This work presents the development of molecularly imprinted polymers (MIPs) for the selective extraction of dimethoate from olive oil. Computational simulations allowed selecting itaconic acid as the monomer showing the highest affinity towards dimethoate. Experimental validation confirmed modelling predictions and showed that the polymer based on IA as functional monomer and omethoate as template molecule displays the highest selectivity for the structurally similar pesticides dimethoate, omethoate and monocrotophos. Molecularly imprinted solid phase extraction (MISPE) method was developed and applied to the clean-up of olive oil extracts. It was found that the most suitable solvents for loading, washing and elution step were respectively hexane, hexane-dichloromethane (85:15%) and methanol. The developed MIPSE was successfully applied to extraction of dimethoate from olive oil, with recovery rates up to 94%. The limits of detection and quantification of the described method were respectively 0.012 and 0.05 μg g(-1). PMID:23290360

  12. Monitoring of N-methyl carbamate pesticide residues in water using hollow fibre supported liquid membrane and solid phase extraction

    NASA Astrophysics Data System (ADS)

    Msagati, Titus A. M.; Mamba, Bhekie B.

    The aim of this work was to develop a method for the determination of N-methyl carbamates in water involving hollow fibre supported liquid membrane (HFSLM) and solid phase extraction (SPE) as sample preparation methods. Four N-methyl carbamate pesticides, aldicarb, carbaryl, carbofuran and methiocarb sulfoxide, were simultaneously extracted and analysed by a liquid chromatograph with a diode array detector (LC-UV/DAD) and a liquid chromatograph coupled to a ion trap quadrupole mass spectrometer (LC-ESI-MS). The high performance liquid chromatography (HPLC) separation of carabamate extracts was performed on a C18 column with water-acetonitrile as the mobile phase. The mass spectrometry analyses were carried out in the positive mode, operating under both the selected ion monitoring (SIM) and full scan modes. The solid phase recoveries of the extracts ranged between 8% and 98%, with aldicarb having the highest recoveries, followed by carbaryl, carbofuran and methiocarb had the lowest recovery. The HFSLM recovery ranged between 8% and 58% and the order of recovery was similar to the SPE trend. Factors controlling the efficiency of the HFSLM extraction such as sample pH, stripping phase pH, enrichment time, stirring speed as well as organic solvent used for entrapment of analytes, were optimised to achieve the highest enrichment factors.

  13. Matrix Solid-Phase Dispersion Extraction and Quantification of Alpinetin in Amomum Seed using Validated HPLC and HPTLC Methods

    PubMed Central

    Singh, M.; Kamal, Y. T.; Khan, M. A.; Parveen, Rabea; Ansari, S. H.; Ahmad, S.

    2015-01-01

    Alpinetin is a flavonoidal constituent of seeds of Amomum subulatum Roxb., recently reported to possess vasorelaxant and antiHIV activities. Simple, accurate and precise HPLC and HPTLC methods were developed for the analysis of alpinetin in A. subulatum seed extracts and extraction technique was optimized to get maximum yield using conventional, ultrasonic and matrix solid phase dispersion extraction. HPLC was performed on a C18 column with methanol and water (70:30, v/v) as mobile phase at a flow rate of 1.0 ml/min whereas HPTLC on silica aluminum sheet (60F254) using toluene, dichloromethane and ethyl acetate as solvent system. A sharp peak was obtained for alpinetin at a retention time (Rt) of 5.7 min by HPLC and retardation factor (Rf) of 0.48 by HPTLC. Both methods were validated as per the ICH guidelines and the content of alpinetin was estimated in different extracts. Matrix solid phase dispersion technique was found most suitable for extracting alpinetin as compared to other techniques. Validation data are indicative of good precision and accuracy and proved the reliability of the methods. PMID:25767318

  14. Magnetic multi-walled carbon nanotubes assisted dispersive solid phase extraction of nerve agents and their markers from muddy water.

    PubMed

    Pardasani, Deepak; Kanaujia, Pankaj K; Purohit, Ajay K; Shrivastava, Anchal Roy; Dubey, D K

    2011-10-30

    The multi-walled carbon nano-tubes (MWCNT) were magnetized with iron oxide nanoparticles and were characterized by SEM and EDX analyses. These magnetized MWCNT (Mag-CNT) were used as sorbent in dispersive solid phase extraction (DSPE) mode to extract nerve agents and their markers. Mag-CNT were dispersed in water and collected with the help of an external magnet. From Mag-CNT, the adsorbed analytes were eluted and analyzed by GC-FPD in phosphorus mode. DSPE was found to be advantageous over conventional solid phase extraction (SPE) in terms of operational simplicity, speed, handling of large sample volume and recoveries. Extraction parameters such as eluting solvent, sorbent amount, pH and salinity of aqueous samples were optimized. Optimized extraction conditions included 40 mg of Mag-CNT as sorbent, chloroform as eluent, pH 3-11 and salinity 20%. Under the optimized conditions, recoveries from distilled water ranged from 60 to 96% and were comparable in tap and muddy water. Limits of quantification and limits of detection of 0.15 ng/ml and 0.05 ng/ml, respectively, were achieved. Superiority of Mag-CNT over conventional C(18) SPE was also established. PMID:22063538

  15. Solid-phase extraction of flavonoids in honey samples using carbamate-embedded triacontyl-modified silica sorbent.

    PubMed

    Liu, Houmei; Zhang, Mingliang; Guo, Yong; Qiu, Hongdeng

    2016-08-01

    In this study, carbamate-embedded triacontyl-modified silica (Sil-CBM-C30) is successfully prepared and used as an efficient sorbent for solid-phase extraction. The extraction performance of the resultant sorbent is evaluated with five flavonoids including myricetin, quercetin, luteolin, kaempferol and isorhamnetin. Main parameters, which affect extraction efficiencies, are carefully investigated and optimized. Comparative experiments between Sil-CBM-C30 and commercial C18 sorbents indicate that the extraction efficiencies of the former one surpass the latter one. The modification of carbamate-embedded triacontyl group on surface of silica causes analytes extracted by hydrophobic, hydrogen bonding and π-π interactions. Under optimal conditions, good linearities and satisfied LODs and LOQs are achieved. The SPE-HPLC-DAD method is successfully developed and applied for the honey sample analysis. PMID:26988475

  16. Accelerated solvent extraction of vitamin K1 in medical foods in conjunction with matrix solid-phase dispersion.

    PubMed

    Chase, G W; Thompson, B

    2000-01-01

    An extraction technique is described for vitamin K1 in medical foods, using accelerated solvent extraction (ASE) in conjunction with matrix solid-phase dispersion (MSPD). The medical food sample is treated as it would be with MSPD extraction, followed by ASE for a hands-free automated extraction. The vitamin K1 in the ASE extract is then quantitated by reversed-phase liquid chromatography with fluorescence detection. The chromatography specifications are identical to those in previous work that used MSPD only, with a limit of detection of 6.6 pg and a limit of quantitation of 22 pg on column. Recoveries, which were determined for an analyte-fortified zero control reference material for medical foods, averaged 97.6% (n = 25) for vitamin K1. The method provides a rapid, automatic, specific, and easily controlled assay for vitamin K1 in fortified medical foods with minimal solvent usage. PMID:10772179

  17. Sorption and desorption of organic matter on solid-phase extraction media to isolate and identify N-nitrosodimethylamine precursors.

    PubMed

    Hanigan, David; Liao, Xiaobin; Zhang, Jinwei; Herckes, Pierre; Westerhoff, Paul

    2016-07-01

    #x02010;Nitrosodimethylamine is mutagenic in rodents, a drinking water contaminant, and a byproduct of drinking water disinfection by chloramination. Nitrosodimethylamine precursor identification leads to their control and improved understanding of nitrosodimethylamine formation during chloramination. Mass balances on nitrosodimethylamine precursors were evaluated across solid-phase extraction cartridges and in eluates to select the best combination of solid-phase media and eluent that maximized recovery of nitrosodimethylamine precursors into a solvent amenable to time-of-flight mass spectrometry analysis. After reviewing literature and comparing various solid-phase cartridges and eluent combinations, a method was obtained to efficiently recover nitrosodimethylamine precursors. The approach with the greatest recoveries of nitrosodimethylamine precursors involved cation exchange resin loaded with water samples at pH 3 and eluted with 5% NH4 OH in methanol. This indicated that nitrosodimethylamine precursors are amines that protonate at low pH and deprotonate at high pH. Quaternary amines were irreversibly sorbed to the cation exchange cartridge and did not account for a large fraction of precursors. Overall, a median recovery of 82% for nitrosodimethylamine precursors was achieved from 11 surface waters and one wastewater. Applying this method allowed discovery of methadone as a new nitrosodimethylamine precursor in wastewater effluent and drinking water treatment plant intakes. PMID:27184503

  18. Molecularly imprinted polymers as the extracted sorbents of clenbuterol ahead of liquid chromatographic determination*

    PubMed Central

    Lay, Sovichea; Yu, Hai-ning; Hu, Bao-xiang; Shen, Sheng-rong

    2016-01-01

    A pre-treatment methodology for clenbuterol hydrochloride (CLEN) isolation and enrichment in a complex matrix environment was developed through exploiting molecularly imprinted polymers (MIPs). CLEN-imprinted polymers were synthesized by the combined use of ally-β-cyclodextrin (ally-β-CD) and methacrylic acid (MAA), allyl-β-CD and acrylonitrile (AN), and allyl-β-CD and methyl methacrylate (MMA) as the binary functional monomers. MAA-linked allyl-β-CD MIPs (M-MAA) were characterized by Fourier transform-infrared (FT-IR) spectroscopy and a scanning electron microscope (SEM). Based upon the results, M-MAA polymers generally proved to be an excellent selective extraction compared to its references: AN-linked allyl-β-CD MIPs (M-AN) and MMA-linked allyl-β-CD MIPs (M-MMA). M-MAA polymers were eventually chosen to run through a molecularly imprinted solid-phase extraction (MISPE) micro-column to enrich CLEN residues spiked in pig livers. A high recovery was achieved, ranging from 91.03% to 96.76% with relative standard deviation (RSD) ≤4.45%. PMID:27256680

  19. Molecularly imprinted polymers as the extracted sorbents of clenbuterol ahead of liquid chromatographic determination.

    PubMed

    Lay, Sovichea; Yu, Hai-Ning; Hu, Bao-Xiang; Shen, Sheng-Rong

    2016-06-01

    A pre-treatment methodology for clenbuterol hydrochloride (CLEN) isolation and enrichment in a complex matrix environment was developed through exploiting molecularly imprinted polymers (MIPs). CLEN-imprinted polymers were synthesized by the combined use of ally-β-cyclodextrin (ally-β-CD) and methacrylic acid (MAA), allyl-β-CD and acrylonitrile (AN), and allyl-β-CD and methyl methacrylate (MMA) as the binary functional monomers. MAA-linked allyl-β-CD MIPs (M-MAA) were characterized by Fourier transform-infrared (FT-IR) spectroscopy and a scanning electron microscope (SEM). Based upon the results, M-MAA polymers generally proved to be an excellent selective extraction compared to its references: AN-linked allyl-β-CD MIPs (M-AN) and MMA-linked allyl-β-CD MIPs (M-MMA). M-MAA polymers were eventually chosen to run through a molecularly imprinted solid-phase extraction (MISPE) micro-column to enrich CLEN residues spiked in pig livers. A high recovery was achieved, ranging from 91.03% to 96.76% with relative standard deviation (RSD) ≤4.45%. PMID:27256680

  20. Interlaboratory comparison of extraction efficiency of pesticides from surface and laboratory water using solid-phase extraction disks.

    PubMed

    Senseman, Scott A; Mueller, Thomas C; Riley, Melissa B; Wauchope, R Don; Clegg, Chris; Young, Roddy W; Southwick, Lloyd M; Moye, H Anson; Dumas, Jose A; Mersie, Wondi; Mattice, John D; Leidy, Ross B

    2003-06-18

    A continuation of an earlier interlaboratory comparison was conducted (1) to assess solid-phase extraction (SPE) using Empore disks to extract atrazine, bromacil, metolachlor, and chlorpyrifos from various water sources accompanied by different sample shipping and quantitative techniques and (2) to compare quantitative results of individual laboratories with results of one common laboratory. Three replicates of a composite surface water (SW) sample were fortified with the analytes along with three replicates of deionized water (DW). A nonfortified DW sample and a nonfortified SW sample were also extracted. All samples were extracted using Empore C(18) disks. After extraction, part of the samples were eluted and analyzed in-house. Duplicate samples were evaporated in a 2-mL vial, shipped dry to a central laboratory (SDC), redissolved, and analyzed. Overall, samples analyzed in-house had higher recoveries than SDC samples. Laboratory x analysis type and laboratory x water source interactions were significant for all four compounds. Seven laboratories participated in this interlaboratory comparison program. No differences in atrazine recoveries were observed from in-house samples analyzed by laboratories A, B, D, and G compared with the recovery of SDC samples. In-house atrazine recoveries from laboratories C and F were higher when compared with recovery from SDC samples. However, laboratory E had lower recoveries from in-house samples compared with SDC samples. For each laboratory, lower recoveries were observed for chlorpyrifos from the SDC samples compared with samples analyzed in-house. Bromacil recovery was <65% at two of the seven laboratories in the study. Bromacil recoveries for the remaining laboratories were >75%. Three laboratories showed no differences in metolachlor recovery; two laboratories had higher recoveries for samples analyzed in-house, and two other laboratories showed higher metolachlor recovery for SDC samples. Laboratory G had a higher

  1. EPA Method 525.3 - Determination of Semivolatile Organic Chemicals in Drinking Water by Solid Phase Extraction and Capillary Column Gas Chromatography/Mass Spectrometry (GC/MS)

    EPA Science Inventory

    Method 525.3 is an analytical method that uses solid phase extraction (SPE) and gas chromatography/mass spectrometry (GC/MS) for the identification and quantitation of 125 selected semi-volatile organic chemicals in drinking water.

  2. Screening and determination of benzodiazepines in whole blood using solid-phase extraction and gas chromatography/mass spectrometry.

    PubMed

    Inoue, H; Maeno, Y; Iwasa, M; Matoba, R; Nagao, M

    2000-09-11

    Benzodiazepines are one of the most widely prescribed drugs for the treatment of a wide spectrum of clinical disorders. They are used as anticonvulsants, anxiolytics, hypnotics or muscle relaxants with different duration of action. In this paper, a simple and sensitive method for the determination of benzodiazepines in whole blood using solid-phase extraction and gas chromatography/mass spectrometry (GC/MS) is described. The drugs spiked in whole blood were extracted with an Oasis HLB solid-phase extraction cartridge (Waters), which contains a copolymer designed to have a hydrophilic-lipophilic balance. GC/MS analysis was performed using a Shimadzu QP-5000 equipped with a BPX5 capillary column (15 mx0.32 mm I.D., film thickness 0.25 microm, SGE). Nineteen benzodiazepines and two thienodiazepines were well separated from each other on their SIM chromatograms and also on the TIC with the exception of oxazolam to cloxazolam separation. The blank extract from whole blood gave no peaks that interfered with all benzodiazepines and thienodiazepines on the chromatogram. The calibration curves for selected benzodiazepines with fludiazepam as an internal standard showed excellent linearity over the concentration range 5-500 ng/ml blood with a correlation coefficients of >0.995. The detection limits ranged from 0.2 to 20 ng/ml blood. The method is simple and sensitive for the determination of benzodiazepines in whole blood and seems to be useful in the practice of forensic science. PMID:10978650

  3. Application of copolymer coated frits for solid-phase extraction of poly cyclic aromatic hydrocarbons in water samples.

    PubMed

    Rahimi, M; Noroozian, E

    2014-07-11

    A conducting copolymer of pyrrole and phenol was electrochemically synthesized on steel frits as a sorbent. The applicability of the frit was assessed for the solid-phase extraction of trace amounts of polycyclic aromatic hydrocarbons (PAHs) in aqueous samples followed by HPLC-UV. The coating produced was very adherent and the scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and FTIR spectrum for the coated frit were studied. The effects of various parameters on the efficiency of the solid-phase extraction process, such as the sample loading rate, elution solvent type, salt effect, volume and flow rate of sample and elution solvent were investigated. Under the optimal conditions, the calibration curves were obtained in the range of 0.1-500ngmL(-1) (r(2)>0.98) and the LODs (S/N=3) were obtained in the range of 0.01-0.08ngmL(-1). Relative standard deviations (RSDs) for intra- and inter-day precision were 2.7-10.2% and 3.6-11.4%, respectively. The recoveries (8 and 40ngmL(-1)) ranged from 79% to 115%. The simplicity of experimental procedure, short sample analysis, high extraction efficiency, and the use of low-cost adsorbent show the potential of this method for routine analysis of PAHs in real samples. PMID:24974869

  4. Analysis of acidic endogenous phytohormones in grapes by using online solid-phase extraction coupled with LC-MS/MS.

    PubMed

    Yu, Jian-Na; Meng, Qing-Yan; Liu, Wen-Jie; Lu, Ya-Ling; Ren, Xiao-Lin

    2014-10-01

    Phytohormones play important roles in regulating numerous plant physiological and developmental processes, even during the postharvest storage period. In order to determine the functions and changes of gibberellins acid (GA3), indoleacetic acid (IAA), abscisic acid (ABA), indolebutyric acid (IBA) and jasmonic acid (JA) in grape berries during storage, an ultrasensitive method based on direct injection online solid-phase extraction coupled with high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed. Grape berries were extracted with cold methanol. After centrifugation, the supernatants were concentrated with a vacuum centrifugal concentrator and injected into an online solid-phase extraction column. After the cleanup procedure, the analytes were determined by LC-MS/MS. The results showed that the linearity of the proposed method was 10-210 µg kg(-1) for ABA, 20-200 µg kg(-1) for IBA, 15-320 µg kg(-1) for IAA, 20-320 µg kg(-1) for GA3 and 3.0-90.0 µg kg(-1) for JA. The limits of detection of the method were 0.71, 2.79, 0.94, 0.39 and 0.57 µg kg(-1), respectively. The proposed method was successfully applied to the analysis of endogenous phytohormones in grape berries during the postharvest storage period. PMID:24200641

  5. On-line solid phase extraction of humic acid from environmental water and monitoring with flow-through chemiluminescence.

    PubMed

    Qu, Jingya; Chen, Hui; Lu, Chao; Wang, Zhihua; Lin, Jin-Ming

    2012-04-21

    An on-line solid phase extraction device combined with flow-through chemiluminescence monitoring was presented for the enrichment and determination of humic acid (HA) in water samples. The chemiluminescence principle was based on the enhancement effect of HA on the Ce(IV)/H(2)SO(4)-rhodamine 6G chemiluminescence system. For sample pretreatment, the on-line solid-phase extraction (SPE) material was packed into a cartridge which was then installed in the manifold. Experimental parameters including reagent concentration, flow rate and extraction time, were optimized. Under the optimized conditions, the relative standard deviation was 3.6% for determining 2 mg L(-1) HA standard solution and the detection limit was 3 μg L(-1). The proposed method was successfully applied to the determination of HA in the range of 0.1-35 mg L(-1). The results were validated by spike recovery experiments. The recovery was from 74.0% to 121%, which was good enough for the determination of HA in environmental waters. PMID:22382709

  6. [Simultaneous determination of 15 industrial synthetic dyes in condiment by solid phase extraction-high performance liquid chromatography].

    PubMed

    Liu, Min; Li, Xiaolin; Bie, Wei; Wang, Minglin; Feng, Qian

    2011-02-01

    A new method was established for the determination of 15 industrial synthetic dyes in condiment by solid phase extraction-high performance liquid chromatography (SPE-HPLC). The samples were extracted by methanol-water (1:1, v/v) and purified by a solid phase extraction column. Then, the chromatographic separation was achieved on a Luna C18 column by linear gradient elution. The mobile phase was 10 mmol/L ammonium acetate-acetonitrile (containing 1% acetic acid). The results showed that the 15 industrial synthetic dyes can be separated efficiently. The recoveries of the 15 industrial synthetic dyes spiked in condiment were between 84.6% and 114.2% with the relative standard deviations of 0.9% - 10.3%. The limits of detection of this method was 0.05 - 0.18 mg/kg for the 15 industrial synthetic dyes. The method is simple, sensitive, accurate, repeatable and can be used for simultaneous determination of the 15 illegally added industrial synthetic dyes. PMID:21598518

  7. [Determination of alkylphenol and alkylphenolpolyethoxylates in brine by solid phase extraction and high performance liquid chromatography-mass spectrometry].

    PubMed

    Wang, Jincheng; Xiong, Li; Zhang, Haijun; Chen, Jiping

    2011-12-01

    A simple method based on solid phase extraction (SPE) coupled with high performance liquid chromatography-mass spectrometry (HPLC-MS) was developed for the determination of octylphenol (OP), nonylphenol (NP), octylphenol ethoxylates (OPEOs) and nonylphenol ethoxylates (NPEOs) in brine. The extraction and cleanup of brine samples were performed on C18 solid-phase extraction cartridges. The complete separation among OP, NP, OPEOs and NPEOs was achieved on a Hypersil GOLD analytical column with methanol-water as the mobile phase. The determination was achieved using HPLC-MS with electrospray ionization (ESI) in selected ion monitoring mode. The results showed that the average recoveries of target compounds were 59.6% - 104.4% and the corresponding relative standard deviations (RSDs, n = 3) were 1.0% - 13.5%. The instrumental limits of detection for the compounds were 0.08 - 3 microg/L. This method was applied to the analysis of the samples of seawater near Dalian coast. The results showed that both NP and NPEOs were detected in all samples and their concentrations in seaport and oil port were much higher than those in other sampling sites. PMID:22500440

  8. Fabrication of ciprofloxacin molecular imprinted polymer coating on a stainless steel wire as a selective solid-phase microextraction fiber for sensitive determination of fluoroquinolones in biological fluids and tablet formulation using HPLC-UV detection.

    PubMed

    Mirzajani, Roya; Kardani, Fatemeh

    2016-04-15

    A molecularly imprinted polymer (MIP) fiber on stainless steel wire using ciprofloxacin template with a mild template removal condition was synthetized and evaluated for fiber solid phase microextraction (SPME) of fluoroquinolones (FQs) from biological fluids and pharmaceutical samples, followed by high performance liquid chromatography analysis with UV detection (HPLC-UV). The developed MIP fiber exhibited high selectivity for the analytes in complex matrices. The coating of the fibers were inspected using fourier transform infrared spectrophotometry, thermogaravimetric analysis, energy dispersive X-ray (EDX) spectroscopy as well as by scanning electron microscopy (SEM). The fiber shows high thermal stability (up to 300°C), good reproducibility and long lifetime. The composite coating did not swell in organic solvents nor did it strip off from the substrate. It was also highly stable and extremely adherent to the surface of the stainless steel fiber. The fabricated fiber exclusively exhibited excellent extraction efficiency and selectivity for some FQs. The effective parameters influencing the microextraction efficiency such as pH, extraction time, desorption condition, and stirring rate were investigated. Under optimized conditions, the limits of detection of the four FQs ranged from 0.023-0.033 μg L(-1) (S/N=5) and the calibration graphs were linear in the concentration range from 0.1-40 μg L(-1), the inter-day and intraday relative standard deviations (RSD) for various FQs at three different concentration level (n=5) using a single fiber were 1.1-4.4% and the fiber to fiber RSD% (n=5) was 4.3-6.7% at 5 μg L(-1) of each anlyetes. The method was successfully applied for quantification of FQs in real samples including serum, plasma and tablet formulation with the recoveries between 97 to 102%. PMID:26852159

  9. Comparison of headspace solid-phase microextraction with conventional extraction for the analysis of the volatile components in Melia azedarach.

    PubMed

    Yang, Yanqin; Xiao, Yanmeng; Liu, Baofeng; Fang, Xuexun; Yang, Wei; Xu, Jingwei

    2011-10-30

    The volatile compositions of Melia azedarach were studied by headspace solid-phase microextraction (HS-SPME). The result was compared with that obtained by soxhlet extraction (SE) and ultrasonic extraction (UAE). 79 compounds were identified in this study, among which 64 compounds were first reported. The experimental parameters including fiber type (PDMS, PDMS-DVB and CAR-PDMS), desorption time, extraction temperature and time were investigated. 37 compounds were obtained by HS-SPME, including curcumene (33.25%), α-cadinol (11.16%), α-muurolene (8.72%), copaene (5.04%), β-bisabolene (3.41%), and α-selinene (2.97%). The result suggested that the HS-SPME method is a powerful analytic tool and complementary to traditional methods for the determination of the volatile compounds in Chinese herbs. PMID:22063551

  10. Determination of organochlorine and pyrethroid pesticides in fruit and vegetables using solid phase extraction clean-up cartridges.

    PubMed

    Sharif, Zawiyah; Man, Yaakob Bin Che; Hamid, Nazimah Sheikh Abdul; Keat, Chin Cheow

    2006-09-15

    A method to determine six organochlorine and three pyrethroid pesticides in grape, orange, tomato, carrot and green mustard based on solvent extraction followed by solid phase extraction (SPE) clean-up is described. The pesticides were spiked into the sample prior to analysis, extracted with ethyl acetate, evaporated and reconstituted with a solvent mixture of acetone:n-hexane (3:7). Three different sorbents (Strong Anion Exchanger/Primary Secondary Amine (SAX/PSA), Florisil and C18) were used for the clean-up step. Pesticides were eluted with 5mL of acetone:n-hexane (3:7, v/v) and determined by gas chromatography and electron-capture detection (GC-ECD). SAX/PSA was the sorbent, which provided chromatograms with less interference and the mean recoveries obtained were within 70-120% except for captafol. The captafol recoveries for grape were within acceptable range with C18 clean-up column. PMID:16857206

  11. Optimization of headspace solid-phase microextraction technique for extraction of volatile smokeless powder compounds in forensic applications.

    PubMed

    Chang, Kah Haw; Yew, Chong Hooi; Abdullah, Ahmad Fahmi Lim

    2014-07-01

    Smokeless powders are low explosives and are potentially found in cases involving firearms and improvised explosive devices. Apart from inorganic compound analysis, forensic determination of organic components of these materials appears as a promising alternative, especially the chromatographic techniques. This work describes the optimization of a solid-phase microextraction technique using an 85 μm polyacrylate fiber followed by gas chromatography-flame ionization detection for smokeless powder. A multivariate experimental design was performed to optimize extraction-influencing parameters. A 2(4) factorial first-order design revealed that sample temperature and extraction time were the major influencing parameters. Doehlert matrix design has subsequently selected 66°C and 21 min as the compromised conditions for the two predetermined parameters. This extraction technique has successfully detected the headspace compounds of smokeless powders from different ammunition types and allowed for their differentiation. The novel technique allows more rapid sample preparation for chromatographic detection of smokeless powders. PMID:24611488

  12. Determination of neonicotinoid pesticide residues in vegetables and fruits with solid phase extraction and liquid chromatography mass spectrometry.

    PubMed

    Obana, Hirotaka; Okihashi, Masahiro; Akutsu, Kazuhiko; Kitagawa, Yoko; Hori, Shinjiro

    2003-04-23

    A rapid and simple extraction method for the simultaneous analysis of five neonicotinoid insecticides has been developed. Twelve different fruit and vegetable matrixes were extracted with methanol and cleaned up using a graphitized carbon solid phase extraction cartridge loading with a 20% methanol solution. The concentrated eluate after methanol elution was then analyzed for pesticide residues by liquid chromatography/mass spectrometry in the APCI positive mode. The five pesticides including nitenpyram, thiamethoxam, imidacloprid, acetamiprid, and thiacloprid were recovered at 70-95% at spike levels of 0.1 and 1 mg/kg in bell pepper, cucumber, eggplant, grape, grapefruit, Japanese radish, peach, pear, potato, rice, and tomato. Relative standard deviations were less than 10% for all of the recovery tests. The proposed method is fast, easy to perform, and could be utilized for regular monitoring of pesticide residues. PMID:12696927

  13. Rationally designed molecularly imprinted polymers for selective extraction of methocarbamol from human plasma.

    PubMed

    Gholivand, Mohammad Bagher; Khodadadian, Mehdi

    2011-09-15

    Molecularly imprinted polymers (MIPs) with high selectivity toward methocarbamol have been computationally designed and synthesized based on the general non-covalent molecular imprinting approach. A virtual library consisting of 18 functional monomers was built and possible interactions between the template and functional monomers were investigated using a semiempirical approach. The monomers with the highest binding scores were then considered for additional calculations using a more accurate quantum mechanical (QM) calculation exploiting the density functional theory (DFT) at B3LYP/6-31G(d,p) level. The cosmo polarizable continuum model (CPCM) was also used to simulate the polymerization solvent. On the basis of computational results, acrylic acid (AA) and tetrahydrofuran (THF) were found to be the best choices of functional monomer and polymerization solvent, respectively. MIPs were then synthesized by the precipitation polymerization method and used as selective adsorbents to develop a molecularly imprinted solid-phase extraction (MISPE) procedure before quantitative analysis. After MISPE the drug could be determined either by differential pulse voltammetry (DPV), on a glassy carbon electrode modified with multiwalled-carbon nanotubes (GC/MWNT), or high performance chromatography (HPLC) with UV detection. A comparative study between MISPE-DPV and MISPE-HPLC-UV was performed. The MISPE-DPV was more sensitive but both techniques showed similar accuracy and precision. PMID:21807239

  14. [Simultaneous determination of nine sulfonamide residues in milk using solid phase extraction and high performance liquid chromatography].

    PubMed

    Wu, Yinliang; Zhao, Li; Liu, Yongjun; Jiang, Yanbin; Liu, Xingguo; Shen, Jianzhong

    2007-09-01

    A simple, rapid, sensitive and reliable high performance liquid chromatographic method for the simultaneous determination of nine sulfonamides (SAs) (sulfadiazine, sulfathiazole, sulfamethazine, sulfamethoxypyridazine, sufamonomethoxine, sulfachloropyridazine, sulfamethoxazole, sulfadimethoxine and sulfaquinoxaline) in milk was developed. The method includes the shaking of the milk with phosphate buffer, centrifugation, and cleaning up on a C18 solid-phase extraction cartridge. The C18 cartridge was washed with water, and the SAs were eluted with methanol. After the evaporation, the residue was dissolved in ethyl acetate, and cleaned up on an amino solid-phase extraction column. Analytical separation was performed on an Inertsil ODS-3 column with photodiode-array detection at 270 nm under the gradient condition. The mean recoveries of SAs at the spiked levels of 10, 20, 40 microg/L were between 72.1% and 88.3%. The relative standard deviations were between 2.3% and 5.0%. The detection limits were 1.7 - 2.8 microg/L, and the quantification limits wer 5.7 - 9.2 microg/L. PMID:18161327

  15. Comparison of the solid-phase extraction efficiency of a bounded and an included cyclodextrin-silica microporous composite for polycyclic aromatic hydrocarbons determination in water samples.

    PubMed

    Mauri-Aucejo, Adela; Amorós, Pedro; Moragues, Alaina; Guillem, Carmen; Belenguer-Sapiña, Carolina

    2016-08-15

    Solid-phase extraction is one of the most important techniques for sample purification and concentration. A wide variety of solid phases have been used for sample preparation over time. In this work, the efficiency of a new kind of solid-phase extraction adsorbent, which is a microporous material made from modified cyclodextrin bounded to a silica network, is evaluated through an analytical method which combines solid-phase extraction with high-performance liquid chromatography to determine polycyclic aromatic hydrocarbons in water samples. Several parameters that affected the analytes recovery, such as the amount of solid phase, the nature and volume of the eluent or the sample volume and concentration influence have been evaluated. The experimental results indicate that the material possesses adsorption ability to the tested polycyclic aromatic hydrocarbons. Under the optimum conditions, the quantification limits of the method were in the range of 0.09-2.4μgL(-1) and fine linear correlations between peak height and concentration were found around 1.3-70μgL(-1). The method has good repeatability and reproducibility, with coefficients of variation under 8%. Due to the concentration results, this material may represent an alternative for trace analysis of polycyclic aromatic hydrocarbons in water trough solid-phase extraction. PMID:27260440

  16. Stir-bar supported micro-solid-phase extraction for the determination of polychlorinated biphenyl congeners in serum samples.

    PubMed

    Sajid, Muhammad; Basheer, Chanbasha

    2016-07-15

    In present work, a new configuration of micro-solid phase extraction was introduced and termed as stir-bar supported micro-solid-phase extraction (SB-μ-SPE). A tiny stir-bar was packed inside the porous polypropylene membrane along with sorbent material and the edges of membrane sheet were heat sealed to secure the contents. The packing of stir-bar inside the μ-SPE device does not allow the device to stick with the wall or any corner of the sample vial during extraction, which is, however, a frequent observation in routine μ-SPE. Moreover, it enhances effective surface area of the sorbent exposed to sample solution through continuous agitation (motion and rotation). It also completely immerses the SB-μ-SPE device in the sample solution even for non-polar sorbents. Polychlorinated biphenyls (PCBs) were selected as model compounds and the method performance was evaluated in human serum samples. After extraction, samples were analyzed by gas chromatography mass spectrometry (GC-MS). The factors that affect extraction efficiency of SB-μ-SPE were optimized. Under optimum conditions, a good linearity (0.1-100ngmL(-1)) with coefficients of determinations ranging from 0.9868 to 0.9992 was obtained. Limits of detections were ranged between 0.003 and 0.047ngmL(-1). Acceptable values for inter-day (3.2-9.1%) and intra-day (3.1-7.2%) relative standard deviations were obtained. The optimized method was successfully applied to determine the concentration of PCB congeners in human serum samples. PMID:27291862

  17. Solid-phase/supercritical-fluid extraction for liquid chromatography of phenolic compounds in freshwater microalgae and selected cyanobacterial species.

    PubMed

    Klejdus, B; Kopecký, J; Benesová, L; Vacek, J

    2009-01-30

    In the present paper a new extraction technique based on the combination of solid-phase/supercritical-fluid extraction (SPE/SFE) with subsequent reversed-phase HPLC is described. The SPE/SFE extractor was originally constructed from SPE-cartridge incorporated into the SFE extraction cell. Selected groups of benzoic acid derivatives (p-hydroxybenzoic, protocatechuic, gallic, vanillic and syringic acid), hydroxybenzaldehydes (4-hydroxybenzaldehyde and 3,4-dihydroxybenzaldehyde) and cinnamic acid derivatives (o-coumaric, p-coumaric, caffeic, ferulic, sinapic and chlorogenic acid) were extracted. Cyclic addition of binary extraction solvent system based on methanol:water (1:1, v/v) and methanol/ammonia aqueous solution was used for extraction at 40MPa and 80 degrees C. The p-hydroxybenzoic, protocatechuic, vanillic, syringic, caffeic and chlorogenic acid; 4-hydroxybenzaldehyde and 3,4-dihydroxybenzaldehyde were identified by HPLC-electrospray mass spectrometry in SPE/SFE extracts of acid hydrolyzates of microalga (Spongiochloris spongiosa) and cyanobacterial strains (Spirulina platensis, Anabaena doliolum, Nostoc sp., and Cylindrospermum sp.). For the identification and quantification of the compounds the quasi-molecular ions [M-H](-) and specific fragments were analysed by quadrupole mass spectrometry analyzer. Our analysis showed that the microalgae and cyanobacteria usually contained phenolic acids or aldehydes at microg levels per gram of lyophilized sample. The proposed SPE/SFE extraction method would be useful for the analysis of different plant species containing trace amount of polar fraction of phenols. PMID:19111311

  18. Determination of fusaric acid in maize using molecularly imprinted SPE clean-up

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new liquid chromatography method to detect fusaric acid in maize is reported based on molecularly imprinted polymer solid phase extraction clean-up (MISPE) using mimic-templated molecularly-imprinted polymers. Picolinic acid was used as a toxin analog for imprinting polymers during a thermolytic s...

  19. A FAST ANALYSIS FOR ATRAZINE, CHLORINATED PESTICIDES AND PCBS IN SURFACE WATERS USING SOLID PHASE EXTRACTION WITH ION TRAP GC/MS/MS DETECTION.

    EPA Science Inventory

    Chlorinated pesticides and PCBs in water are extracted onto divinyl benzene solid phase extraction disks then eluted with acetone and hexane solvents. The extracts are analyzed using an ion trap GC/MS/MS detector. This method reduces sample preparation time, solvent usage and low...

  20. Halloysite Nanotubes as a New Adsorbent for Solid Phase Extraction and Spectrophotometric Determination of Iron in Water and Food Samples

    NASA Astrophysics Data System (ADS)

    Samadi, A.; Amjadi, M.

    2016-07-01

    Halloysite nanotubes (HNTs) have been introduced as a new solid phase extraction adsorbent for preconcentration of iron(II) as a complex with 2,2-bipyridine. The cationic complex is effectively adsorbed on the sorbent in the pH range of 3.5-6.0 and efficiently desorbed by trichloroacetic acid. The eluted complex has a strong absorption around 520 nm, which was used for determination of Fe(II). After optimizing extraction conditions, the linear range of the calibration graph was 5.0-500 μg/L with a detection limit of 1.3 μg/L. The proposed method was successfully applied for the determination of trace iron in various water and food samples, and the accuracy was assessed through the recovery experiments and analysis of a certified reference material (NIST 1643e).

  1. Solid-phase extraction coupled with HPLC-DAD for determination of B vitamin concentrations in halophytes.

    PubMed

    Chamkouri, Narges; Khodadoust, Saeid; Ghalavandi, Forogh

    2015-01-01

    In our study, a simple and sensitive method was proposed for determination of vitamins B group in leaves of Suaeda aegyptiaca and Suaeda Vera (Halophytes) by HPLC-DAD with solid-phase extraction (SPE) as the preconcentration step. The variables affecting the extraction and determination conditions were investigated and optimized. A preconcentration step based on SPE is necessary to remove interfering components. The limit of detection obtained was <5 mg kg(-1), the relative standard deviation (RSD) was <4%, and the recovery was in the range of 91-102%. The linear correlation coefficient was 0.999. The method was successfully applied to determine group B vitamins in the halophyte samples. As a whole, these findings may confirm the interesting potential of this halophyte as a valuable source of natural bioactive molecules. PMID:26153382

  2. Graphene nanoplatelets as a highly efficient solid-phase extraction sorbent for determination of phthalate esters in aqueous solution.

    PubMed

    Luo, Xi; Zhang, FeiFang; Ji, Shunli; Yang, Bingcheng; Liang, Xinmiao

    2014-03-01

    Graphene nanoplatelet (GN) as a solid-phase extraction (SPE) sorbent in combination with high performance liquid chromatography has been used for the determination of five phthalate esters (PAEs) in aqueous solution. The operation parameters affecting the extraction efficiency were optimized. Comparative studies showed that GN was superior to other common SPE sorbents in terms of recovery and adsorption capacity. Under optimization conditions, detection limits of 0.09-0.33 ng mL(-1) were achieved for five PAEs and enrichment factors of 402-711 for the analytes were obtained. The proposed method was successfully applied for the determination of PAEs in tap water and drink samples with recoveries ranging from 87.7% to 100.9%. PMID:24468344

  3. Solid phase micro extraction - A new technique coupled with gas chromatograph for chloroethene analysis from aqueous samples

    SciTech Connect

    Xu, N.; Sewell, G.W.

    1996-10-01

    Once the chloroethenes (tetrachloroethene and trichloroethene) contamination occurs in the subsurface environment, they tend to retain and form a Pollution plum in the aquifer because of their recalcitrance to aerobic oxidation. Currently, the most promising bioremediation method for chlorinated compounds is through anaerobic reductive biotransformation, in which each chlorine is replaced by a hydrogen. To study the biodegradation process, it is essential to monitor tetrachloroethene and its degradation daughter products frequently. An analytical method has been modified for chloroethene analysis by gas chromatography. Solid Phase Micro Extraction technique has been used to extract aqueous sample onto a fiber and then to desorb the sample directly into a gas chromatograph injection port. The total run time is less than 17 minutes.

  4. Solid-phase extraction based on ground methacrylate monolith modified with gold nanoparticles for isolation of proteins.

    PubMed

    Vergara-Barberán, María; Lerma-García, María Jesús; Simó-Alfonso, Ernesto Francisco; Herrero-Martínez, José Manuel

    2016-04-21

    In this study, a novel polymeric material functionalized with gold nanoparticles (AuNPs) was prepared as solid-phase extraction (SPE) sorbent for isolation of proteins. The sorbent was synthesized from a powdered poly(glycidyl-co-ethylene dimethacrylate) monolith, and modified with ammonia, followed by immobilization of AuNPs on the pore surface of the material. To evaluate the performance of this SPE support, proteins were selected as test solutes, being the extraction conditions and other parameters (loading capacity and regenerative ability of sorbent) established. The results indicated that this sorbent could be employed to selectively capture proteins according to their pI, on the basis of the strong affinity of these biomacromolecules towards to AuNPs surface. The applicability of this sorbent was demonstrated by isolating protein species of interest (bovine serum albumin, cytochrome c and lectins in European mistletoe leaves), followed by SDS-PAGE analysis. PMID:27026598

  5. Determination of Chlorophenols in Water Samples Using Solid-Phase Extraction Enrichment Procedure and Gas Chromatography Analysis.

    PubMed

    Ben Hassine, S; Hammami, B; Touil, S; Driss, M R

    2015-11-01

    Solid-phase extraction (SPE) procedure followed by derivatization and gas chromatography electron capture detection was evaluated for the determination of trace amounts of chlorophenols (CPs) in waters samples. Different parameters affecting extraction efficiency such as, volume of elution solvent, volume and pH of water sample, quantity of sorbent phase were studied and optimized. SPE was carried out on polystyrene-divinylbenzene (Bond Elut ENV) and high recoveries were obtained using 1000 mg of this cartridge for the treatment of 500 mL of acidified water sample. The described method was then tested on spiked tap, mineral, ground and surface water samples. The overall procedure provided limits of detection lower than 20 ng L(-1), recoveries of 70%-106% and an enrichment factor of 500 for the examined CPs in 500 mL water samples. Among the studied compounds, pentachlorophenol was detected in tap water at a concentration level of 0.06 µg L(-1). PMID:26067701

  6. Magnetic nano graphene oxide as solid phase extraction adsorbent coupled with liquid chromatography to determine pseudoephedrine in urine samples.

    PubMed

    Taghvimi, Arezou; Hamishehkar, Hamed; Ebrahimi, Mahmoud

    2016-01-15

    This paper reports on a method based on magnetic solid phase extraction (MSPE) for the determination of pseudoephedrine. Magnetic nanographene oxide (MNGO) was applied as a new adsorbent for the extraction of pseudoephedrine from urine samples. Synthesis of MNGO was characterized by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), powder X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). The main factors influencing extraction efficiency, including the amounts of sample volume, amount of adsorbent, type and amount of extraction organic solvent, time of extraction and desorption, pH, ionic strength of extraction medium, and agitation rate, were investigated and optimized. Under optimized extraction conditions, a good linearity was observed in the range of 100-2000ng/mL with a correlation coefficient of 0.9908 (r(2)). Limit of detection (LOD) and limit of quantification (LOQ) were 25 and 82.7ng/mL, respectively. Inter-day and intra-day precision and accuracy were 6.01 and 0.34 (%), and 8.70 and 0.29 (%), respectively. The method was applied for the determination of pseudoephedrine in urine samples of volunteers receiving pseudoephedrine with the recovery of 96.42. It was concluded that the proposed method can be applied in diagnostic clinics. PMID:26708626

  7. DNA purification using dynamic solid-phase extraction on a rotationally-driven polyethylene-terephthalate microdevice.

    PubMed

    Jackson, K R; Borba, J C; Meija, M; Mills, D L; Haverstick, D M; Olson, K E; Aranda, R; Garner, G T; Carrilho, E; Landers, J P

    2016-09-21

    We report the development of a disposable polyester toner centrifugal device for semi-automated, dynamic solid phase DNA extraction (dSPE) from whole blood samples. The integration of a novel adhesive and hydrophobic valving with a simple and low cost microfabrication method allowed for sequential addition of reagents without the need for external equipment for fluid flow control. The spin-dSPE method yielded an average extraction efficiency of ∼45% from 0.6 μL of whole blood. The device performed single sample extractions or accommodate up to four samples for simultaneous DNA extraction, with PCR-readiness DNA confirmed by effective amplification of a β-globin gene. The purity of the DNA was challenged by a multiplex amplification with 16 targeted amplification sites. Successful multiplexed amplification could routinely be obtained using the purified DNA collected post an on-chip extraction, with the results comparable to those obtained with commercial DNA extraction methods. This proof-of-principle work represents a significant step towards a fully-automated low cost DNA extraction device. PMID:27590539

  8. Solid phase nucleic acid extraction technique in a microfluidic chip using a novel non-chaotropic agent: dimethyl adipimidate.

    PubMed

    Shin, Yong; Perera, Agampodi Promoda; Wong, Chee Chung; Park, Mi Kyoung

    2014-01-21

    Here, we present a silicon microfluidic system for the purification and extraction of nucleic acids from human body fluid samples utilizing a dimethyl adipimidate (DMA)-based solid-phase extraction method. We propose DMA, which has been used as an amino-reactive cross-linking agent within cells and proteins, as a non-chaotropic reagent for the capture of nucleic acids to overcome the limitations of existing chaotropic and non-chaotropic techniques such as low binding efficiency, PCR inhibition and so on. DMA contains bi-functional imidoesters that form reversible cross-linking structures with DNA therefore providing a high surface-area to volume ratio for capturing DNA without structurally modifying microfluidic channels. In this work, we have first demonstrated highly efficient capture and purification of genomic DNA (T24 cell line) with DMA using a label-free silicon microring resonator sensor device. In addition, we observed the improvement of the DNA amplification efficiency by using the proposed technique for both the genetic (HRAS) and epigenetic (RARβ) analysis of DNA biomarkers. Particularly, we confirmed that the DMA-based solid-phase extraction technique can be applied for the extraction of genomic DNA with higher purity (p < 0.001) using human body fluids (blood and urine) in silicon microfluidic devices compared to other chaotropic methods. Therefore, the proposed technique would be able to harmonize with a micro-total analysis system platform for the analysis of genetic and epigenetic DNA biomarkers related to human diseases in the field of point-of-care (POC) diagnostic applications. PMID:24263404

  9. Determination of ibuprofen in combined dosage forms and cream by direct UV spectrophotometry after solid-phase extraction.

    PubMed

    Sunaric, Slavica; Petkovic, Milica; Denic, Marko; Mitic, Snezana; Pavlovic, Aleksandra

    2013-01-01

    Solid-phase extraction method followed by direct UV spectrophotometry at 264 nm was developed and applied for the selective ibuprofen determination in two-component formulation of ibuprofen and pseudoephedrine-HCl, combined powder which contains ibuprofen in the form of salt with L-arginine and 10% ibuprofen cream. Procedures for ibuprofen determination in complex pharmaceutical preparations by direct UV spectrophotometry lack selectivity because of interferences of other active substances and fat components. A limited number of spectrophotometric methods applicable to these samples are based on derivative (first and second-order) UV spectroscopy. Common HPLC procedures are more selective but more expensive and for creams also require some type of extraction because the large amount of oily excipients would clog up the column. The proposed solid-phase extraction method proved to be suitable for analysis of ibuprofen in combined tablets, powders and creams by direct UV spectrophotometry. Also the method provides an effective clean-up of the cream and allows ibuprofen determination by HPLC analysis. For the extraction three different commercial sorbents were tested: anion exchange Oasis MAX, hydrophilic-lipophilic balanced Oasis HLB and reverse-phase Chromabond C18ec. The optimization of the SPE method was first done on standard ibuprofen solutions and then the suitability of the method was checked on solutions of commercial pharmaceutical samples. The method yields good results for all three types of commercial preparations on the anion-exchange Oasis MAX cartridges, with recoveries of 90-100.2%. The interferences in UV analysis were not registered and good precision (RSD < 6%) was obtained. The present method has been verified as accurate as the reference HPLC with the great advantage of less expensive instrumentation. For this reason, the method would be suitable for a routine and rapid drug quality control. PMID:23757930

  10. The evaluation of solid phase micro-extraction fibre types for the analysis of organic components in unburned propellant powders.

    PubMed

    Dalby, Oliver; Birkett, Jason W

    2010-11-12

    This work describes the evaluation of various solid phase micro-extraction (SPME) fibre types for the detection of compounds originating from particles of unburned propellant powders. These compounds may also be found in association with organic gunshot residues (OGSR). Seven SPME fibres were assessed based on their ability to extract the compounds of interest (diphenylamine (DPA), 4-nitrodiphenylamine (4-NDPA), ethyl centralite (EC), nitroglycerin (NG) and dibutyl phthalate (DBP)) from four ammunition types across three calibres (9 mm, 5.56 mm and 7.62 mm). Extracts were analysed by gas chromatography/mass spectrometry (GC/MS). Results indicated that the 65 μm polydimethylsiloxane/divinylbenzene (PDMS/DVB) was the most suitable fibre type for the extraction of these compounds across the ammunition types tested. Optimal extraction time parameters were also assessed with a 35-min period determined to be suitable. A number of previously unreported considerations for extracting propellant powders and potentially OGSR related materials are discussed. PMID:20933233

  11. Preconcentration and analysis of Rhodamine B in water and red wine samples by using magnesium hydroxide/carbon nanotube composites as a solid-phase extractant.

    PubMed

    Wu, Zhi-Liang; Liu, Qi; Chen, Xiao-Qing; Yu, Jin-Gang

    2015-10-01

    A convenient and accurate analysis approach that combined solid-phase extraction and high-performance liquid chromatography was developed to determine the amount of Rhodamine B in red wine and Xiang-jiang river water samples. A novel composite, magnesium hydroxide/carbon nanotube composites, was synthesized and used as the solid-phase extractant for the preconcentration/analysis of Rhodamine B. Magnesium hydroxide/carbon nanotube composites, which combined the merits of carbon nanotubes and magnesium hydroxide, exhibited acceptable adsorption and desorption efficiencies for Rhodamine B. The linear range of the proposed solid-phase extraction with high-performance liquid chromatography method for Rhodamine B was 0.05-20.0 mg/L, with a limit of detection of 3.6 μg/L. The precision and reproducibility of the developed solid-phase extraction with high-performance liquid chromatography method and the batch-to-batch reproducibility of the solid-phase extractant were also validated at spiking levels of 0.5 and 2.0 mg/L. The recovery of Rhodamine B was 94.33-106.7%, and the recovery relative standard deviations of the intra- and interday precisions were ≤ 3.83 and ≤ 6.01%, respectively. The relative standard deviation of the batch-to-batch reproducibility was ≤ 7.98%. PMID:26179418

  12. Magnetic graphene solid-phase extraction for the determination of carbamate pesticides in tomatoes coupled with high performance liquid chromatography.

    PubMed

    Li, Na; Chen, Juan; Shi, Yan-Ping

    2015-08-15

    Graphene-based magnetic nanoparticles, comprising zero-valent iron, iron oxide-oxyhydroxide and graphene, were prepared through a simple one-step synthesis method, and subsequently applied to magnetic solid-phase extraction for the determination of trace carbamate pesticides in tomatoes coupled with high performance liquid chromatography. The properties of the nanocomposites were confirmed by using Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and vibrating sample magnetometer. The components within the nanocomposites endowed the material with high extraction performance and manipulative convenience. Compared with reduced graphene oxide, the as-prepared G-MNPs showed the better extraction efficiencies for the carbamate pesticides thanks to the contribution of the iron-containing magnetic nanoparticles to the adsorption capacity of the nanocomposites. Various experimental parameters affecting the extraction efficiency had been investigated in detail. Under the optimal conditions, the method provided high enrichment factors ranging from 364 to 434, good linearities ranging from 5 to 200ng g(-1) for metolcarb, baygon and methiocarb and 10 to 200ng g(-1) for carbofuran and isoprocarb, low limits of detection ranging from 0.58 to 2.06ng g(-1), and satisfactory spiked recoveries (between 90.34% and 101.98% with the relative standard deviation values from 1.21% to 5.93%). It was confirmed that this novel method was an efficient pretreatment and enrichment procedure and could be successfully applied for extraction and determination of trace carbamate pesticides in complex matrices. PMID:25966405

  13. Electric field-assisted solid phase extraction and cleanup of ionic compounds in complex food matrices: Fluoroquinolones in eggs.

    PubMed

    Ribeiro, Cyntia Cabral; Orlando, Ricardo Mathias; Rohwedder, Jarbas José Rodrigues; Reyes, Felix Guillermo Reyes; Rath, Susanne

    2016-05-15

    The use of electric fields as additional driving forces in sample preparation techniques is an innovative approach that is environmentally friendly, straightforward, and able to overcome several limitations of conventional sample preparation procedures. In this work, the advantages of electric field-assisted solid phase extraction (E-SPE) using syringe-type cartridges were demonstrated for the extraction of four fluoroquinolones (FQs) in their anionic forms. The FQs were extracted from eggs and subsequently determined by UHPLC-MS/MS. The use of electric fields during the washing and final elution steps resulted in a significant improvement of the extraction efficiencies for almost all FQs when compared to conventional SPE. Intra- and inter-day assays showed coefficients of variation below 10%. The better cleanup also resulted in the appearance of less precipitated matter in the final eluate, as well as reduced matrix effects. The results showed that the electrophoretic forces derived from electric fields are a promising way of significantly increasing the extraction efficiency of ionic analytes, while minimizing matrix effects associated with complex samples. PMID:26992547

  14. Sol-gel titania-coated needles for solid phase dynamic extraction-GC/MS analysis of desomorphine and desocodeine.

    PubMed

    Su, Chi-Ju; Srimurugan, Sankarewaran; Chen, Chinpiao; Shu, Hun-Chi

    2011-01-01

    Novel sol-gel titania film coated needles for solid-phase dynamic extraction (SPDE)-GC/MS analysis of desomorphine and desocodeine are described. The high thermal stability of titania film permits efficient extraction and analysis of poorly volatile opiate drugs. The influences of sol-gel reaction time, coating layer, extraction and desorption time and temperature on the SPDE needle performance were investigated. The deuterium labeled internal standard was introduced either during the extraction of analyte or directly injected to GC after the extraction process. The latter method was shown to be more sensitive for the analysis of water and urine samples containing opiate drugs. The proposed conditions provided a wide linear range (from 5-5000 ppb), and satisfactory linearity, with R(2) values from 0.9958 to 0.9999, and prominent sensitivity, LOQs (1.0-5.0 ng/g). The sol-gel titania film coated needle with SPDE-GC/MS will be a promising technique for desomorphine and desocodeine analysis in urine. PMID:22076337

  15. Magnetic nanocomposite of self-doped polyaniline-graphene as a novel sorbent for solid-phase extraction.

    PubMed

    Mehdinia, Ali; Esfandiarnejad, Reyhaneh; Jabbari, Ali

    2015-01-01

    This work is the first study on the extraction efficiency of self-doped polyaniline that is immobilized on the graphene-modified magnetic nanoparticles. The new material was used as a sorbent for the magnetic solid-phase extraction of methyl-, propyl-, and butylparabens. The use of graphene provides a high surface area and prevents aggregation of the nanoparticles. The self-doped polyaniline also provides multifunctionality, high extraction capacity, and chemical stability even in the basic medium. The parabens were acetylated for determination by gas chromatography with flame ionization detection. The effects of monomer ratio, extraction solvent, sorbent amount, sample volume, desorption solvent volume, adsorption and desorption times, and sample ionic strength were optimized. Preconcentration factors obtained were from 190 to 310. The detection limits of the method were <2.8 μg/L. Linear ranges of the method were 5-2000 μg/L for propyl and butyl parabens, and 10-2000 μg/L for methyl paraben. The method was applied for the determination of the parabens in cosmetic products and extraction recoveries were 89-101% with RSDs ≤7.9%. PMID:25354138

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

    PubMed

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

    2012-12-15

    In this work, a rapid and reliable purification method based on a single mixed solid phase extraction (SPE) column, for the determination of acrylamide in roasted coffee by liquid chromatography-tandem mass spectrometry, was developed. Deuterium labelled d(3)-acrylamide was used as internal standard. Acrylamide was extracted by 10 mL of water and the extract purified by a single SPE column consisting of 0.5 g of an in-house prepared mixture of C18, strong cation (SCX) and anion exchange (SAX) sorbents in the ratio 2/1.5/1.5 (w/w/w). The amount of the three sorbents was optimised in order to eliminate the main interfering compounds present in coffee extracts, such as melanoidins, trigonelline, chlorogenic acids and caffeine. The SPE procedure was very simple and consisted of pushing 1 mL of an aqueous coffee extract through the SPE column followed by 1 mL of water which was collected for the analysis. The method was tested on six samples of roasted coffee of different composition and roasting level. The repeatability of the method, expressed as relative standard deviation (n=6), was lower than 5%. The recovery of acrylamide at three spiked levels ranged from 92% to 95%. The limits of detection (LOD) and quantitation (LOQ) were 5 and 16 μg kg(-1), respectively. PMID:22980859

  17. A solid phase extraction based non-disruptive sampling technique to investigate the surface chemistry of macroalgae.

    PubMed

    Cirri, Emilio; Grosser, Katharina; Pohnert, Georg

    2016-01-01

    The surface chemistry of aquatic organisms determines their biotic interactions. Metabolites in the spatially limited laminar boundary layer mediate processes, such as antifouling, allelopathy and chemical defense against herbivores. However, very few methods are available for the investigation of such surface metabolites. An approach is described in which surfaces are extracted by means of C18 solid phase material. By powdering wet algal surfaces with this material, organic compounds are adsorbed and can be easily recovered for subsequent liquid chromatography/mass spectrometry (LC/MS) and gas chromatography/mass spectrometry (GC/MS) investigations. The method is robust, picks up metabolites of a broad polarity range and is easy to handle. It is more universal compared to established solvent dipping protocols and it does not cause damage to the test organisms. A protocol is introduced for the macroalgae Fucus vesiculosus, Caulerpa taxifolia and Gracilaria vermiculophylla, but it can be easily transferred to other aquatic organisms. PMID:26795737

  18. Determination of Six Pyrazole Fungicides in Grape Wine by Solid-Phase Extraction and Gas Chromatography-Tandem Mass Spectrometry.

    PubMed

    Shen, Yan; Li, Zhou; Ma, Qiang; Wang, Chuanxian; Chen, Xiangzhun; Miao, Qian; Han, Chao

    2016-05-18

    A gas chromatography-tandem mass spectrometry (GC-MS/MS) method was developed for the first simultaneous identification and quantification of six pyrazole fungicides (furametpyr, rabenzazole, fluxapyroxad, penflufen, bixafen, and isopyrazam) in grape wine samples. The grape wine samples were first diluted with water, then purified by solid-phase extraction, and finally examined by GC-MS/MS in multiple reaction monitoring (MRM) mode. Matrix-matched calibration curves were used to correct the matrix effects. The limits of quantification (LOQs), calculated as 10 times the standard deviation, were 0.2-0.8 μg kg(-1) for the six pyrazole fungicides. The average recoveries were in the range of 74.3-94.5%, with relative standard deviations (RSDs) below 5.8%, measured at three concentration levels. The proposed method is suitable for the simultaneous determination of six pyrazole fungicides in grape wine samples. PMID:27112545

  19. An analytical method for the determination of perfluorinated compounds in whole blood using acetonitrile and solid phase extraction methods.

    PubMed

    Yeung, Leo W Y; Taniyasu, Sachi; Kannan, Kurunthachalam; Xu, Della Z Y; Guruge, Keerthi S; Lam, Paul K S; Yamashita, Nobuyoshi

    2009-06-19

    A method for the analysis of perfluorinated compounds (perfluoroalkyl sulfonates: C4, C6, C8, C10; perfluoroalkyl sulfinates: C6, C8, C10; perfluorooctanesulfonamide, N-ethyl perfluorooctanesulfonamide, N-ethyl perfluorooctanesulfonamidoacetate, perfluorocarboxylates: C4-C14; fluorotelomer carboxylate (7:3, 8:2) in whole blood using acetonitrile and OASIS WAX solid phase extraction (SPE) cartridge was developed. Separation of target compounds in two HPLC columns (ion exchange JJ50-2D and C18 Betasil columns) was examined. Matrix recoveries of the developed methods ranged from 70% to 120%. Separation of possible inferences such as taurodeoxycholic acid (TDC) was accomplished using an ion exchange JJ50-2D column, and this separation was validated using whole blood of different animals. PMID:19439311

  20. Colorimetric Solid Phase Extraction for the Measurement of Total I (Iodine, Iodide, and Triiodide) in Spacecraft Drinking Water

    NASA Technical Reports Server (NTRS)

    Lipert, Robert J.; Porter, Marc D.; Siperko, Lorraine M.; Gazda, Daniel B.; Rutz, Jeff A.; Schultz, John R.; Carrizales, Stephanie M.; McCoy, J. Torin

    2009-01-01

    An experimental drinking water monitoring kit for the measurement of iodine and silver(I) was recently delivered to the International Space Station (ISS). The kit is based on Colorimetric Solid Phase Extraction (CSPE) technology, which measures the change in diffuse reflectance of indicator disks following exposure to a water sample. To satisfy additional spacecraft water monitoring requirements, CSPE has now been extended to encompass the measurement of total I (iodine, iodide, and triiodide) through the introduction of an oxidizing agent, which converts iodide and triiodide to iodine, for measurement using the same indicator disks currently being tested on ISS. These disks detect iodine, but are insensitive to iodide and triiodide. We report here the operational considerations, design, and ground-based performance of the CSPE method for total I. The results demonstrate that CSPE technology is poised to meet NASA's total I monitoring requirements.

  1. Determination of enrofloxacin by room-temperature phosphorimetry after solid phase extraction on an acrylic polymer sorbent

    NASA Astrophysics Data System (ADS)

    de Souza, Cabrini F.; Martins, Renata K. S.; da Silva, Andrea R.; da Cunha, Alessandra L. M. C.; Aucélio, Ricardo Q.

    A phosphorimetric method was developed to enable the determination of enrofloxacin using photochemical derivatization which was used to both improve detection limits and to minimize the uncertainty of measurements. Phosphorescence was induced on cellulose containing TlNO3. Absolute limit of detection at the ng range and linear analytical response over three orders of magnitude were achieved. A metrological study was made to obtain the combined uncertainty value and to identify that the precision was mainly affected by the changing of substrates when measuring the signal from each replicate. Pharmaceutical formulations containing enrofloxacin were successfully analyzed by the method and the results were similar to the ones achieved using a HPLC method. A solid phase extraction on an acrylic polymer was optimized to separate enrofloxacin from interferents such as diclofenac and other components from biological matrices, which allowed the successful use of the method in urine analysis.

  2. Comprehensive analysis of protein glycosylation by solid-phase extraction of N-linked glycans and glycosite-containing peptides

    PubMed Central

    Sun, Shisheng; Shah, Punit; Eshghi, Shadi Toghi; Yang, Weiming; Trikannad, Namita; Yang, Shuang; Chen, Lijun; Aiyetan, Paul; Höti, Naseruddin; Zhang, Zhen; Chan, Daniel W; Zhang, Hui

    2016-01-01

    Comprehensive characterization of protein glycosylation is critical for understanding the structure and function of glycoproteins. However, due to the complexity and heterogeneity of glycoprotein conformations, current glycoprotein analyses focus mainly on either the de-glycosylated glycosylation site (glycosite)-containing peptides or the released glycans. Here, we describe a chemoenzymatic method called solid phase extraction of N-linked glycans and glycosite-containing peptides (NGAG) for the comprehensive characterization of glycoproteins that is able to determine glycan heterogeneity for individual glycosites in addition to providing information about the total N-linked glycan, glycosite-containing peptide and glycoprotein content of complex samples. The NGAG method can also be applied to quantitatively detect glycoprotein alterations in total and site-specific glycan occupancies. PMID:26571101

  3. Comprehensive analysis of protein glycosylation by solid-phase extraction of N-linked glycans and glycosite-containing peptides.

    PubMed

    Sun, Shisheng; Shah, Punit; Eshghi, Shadi Toghi; Yang, Weiming; Trikannad, Namita; Yang, Shuang; Chen, Lijun; Aiyetan, Paul; Höti, Naseruddin; Zhang, Zhen; Chan, Daniel W; Zhang, Hui

    2016-01-01

    Comprehensive characterization of protein glycosylation is critical for understanding the structure and function of glycoproteins. However, due to the complexity and heterogeneity of glycoprotein conformations, current glycoprotein analyses focus mainly on either the de-glycosylated glycosylation site (glycosite)-containing peptides or the released glycans. Here, we describe a chemoenzymatic method called solid phase extraction of N-linked glycans and glycosite-containing peptides (NGAG) for the comprehensive characterization of glycoproteins that is able to determine glycan heterogeneity for individual glycosites in addition to providing information about the total N-linked glycan, glycosite-containing peptide and glycoprotein content of complex samples. The NGAG method can also be applied to quantitatively detect glycoprotein alterations in total and site-specific glycan occupancies. PMID:26571101

  4. Solid-phase extraction strategies to surmount body fluid sample complexity in high-throughput mass spectrometry-based proteomics.

    PubMed

    Bladergroen, Marco R; van der Burgt, Yuri E M

    2015-01-01

    For large-scale and standardized applications in mass spectrometry- (MS-) based proteomics automation of each step is essential. Here we present high-throughput sample preparation solutions for balancing the speed of current MS-acquisitions and the time needed for analytical workup of body fluids. The discussed workflows reduce body fluid sample complexity and apply for both bottom-up proteomics experiments and top-down protein characterization approaches. Various sample preparation methods that involve solid-phase extraction (SPE) including affinity enrichment strategies have been automated. Obtained peptide and protein fractions can be mass analyzed by direct infusion into an electrospray ionization (ESI) source or by means of matrix-assisted laser desorption ionization (MALDI) without further need of time-consuming liquid chromatography (LC) separations. PMID:25692071

  5. Methylene crosslinked calix[6]arene hexacaarboxylic acid resin: a highly efficient solid phase extractant for decontamination of lead bearing effluents.

    PubMed

    Adhikari, Birendra Babu; Gurung, Manju; Kawakita, Hidetaka; Jumina; Ohto, Keisuke

    2011-10-15

    Calixarene-based cation exchange resin has been developed by methylene crosslinking of calix[6]arene hexacarboxylic acid derivative and the resin has been exploited for solid phase extraction of some toxic heavy metal ions. The selectivity order of the resin towards some metal ions follows the order Pb(II) > Cu(II)> Zn(II), Ni(II), Co(II). The maximum lead ion binding capacity of the resin was found to be 1.30 mmol g(-1) resin. The loaded lead was quantitatively eluted with dilute acid solution regenerating the resin. Mutual separation of Pb(II), Cu(II) and Zn(II) was achieved by using the column packed with the resin. PMID:21835544

  6. Graphene aerogel based monolith for effective solid-phase extraction of trace environmental pollutants from water samples.

    PubMed

    Han, Qiang; Liang, Qionglin; Zhang, Xiaoqiong; Yang, Liu; Ding, Mingyu

    2016-05-20

    Graphene aerogel (GA), a typical kind of three-dimensional (3D) macroscopic assembly, not only provides inherently excellent properties of graphene sheets (GS), but also exhibits interesting characteristics of the 3D macroporous architecture including large and tunable pore volumes, high specific surface areas and fast mass transport kinetics. Thus, it is rational to expect GA to be an efficient adsorbent for solid-phase extraction (SPE). In this paper, a novel GA monolith based solid-phase extraction method was investigated in the application of environment analysis. The GA monolith based SPE cartridge was fabricated directly in the empty cartridge through template-free "sol-cryo" method. Due to the efficient mass transfer, more adsorption sites as well as effective retention for the analytes, the adsorption property of GA for bisphenol A revealed better performance than that of GS. What's more, GA also outperformed in loading and eluting for target analysis. On the basis of the above advantages, the obtained cartridge was applied for the separation of environmental pollutants from water samples. Taking endocrine disrupting chemicals and polychlorinated biphenyls as the polar and weak polar model analytes, optimizing several parameters influencing the recoveries, limits of detection in the range of 0.01-0.11ngmL(-1) and 0.19-1.53ngL(-1) for the two series of compounds were provided by the established methods. The satisfied sensitivity was accessed and recoveries ranging from 76.3 to 112.5% were obtained for all the analytes when the proposed methods were applied in real water samples analysis. The results revealed the potential of GA as an effective sorbent in sample preparation processes. PMID:27095129

  7. Streamlined sample cleanup using combined dispersive solid-phase extraction and in-vial filtration for analysis of pesticides and environmental pollutants in shrimp

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new method of sample preparation was developed and is reported for the first time. The approach combines in-vial filtration with dispersive solid-phase extraction (d-SPE) in a fast and convenient cleanup of QuEChERS (quick, easy, cheap, effective, rugged, and safe) extracts. The method was appli...

  8. ALTERNATIVES TO METHANOL WATER ELUTION OF SOLID-PHASE EXTRACTION COLUMNS FOR THE FRACTIONATION OF HIGH LOG KOW ORGANIC COMPOUNDS IN AQUEOUS ENVIRONMENTAL SAMPLES

    EPA Science Inventory

    A toxicity-directed method for fractionating non-polar organic toxicants using solid-phase extraction (SPE) is described in phase II of EPA's "Methods for Aquatic Toxicity Evaluations". his method has been used very successfully to extract and fractionate acutely and chronically ...

  9. Comparison of characteristic flavor and aroma volatiles in melons and standards using solid phase microextraction (SPME) and Stir Bar Sorptive Extraction (SBSE) with GC-MS.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stir bar sorptive extraction (SBSE) is a technique for extraction and analysis of organic compounds in aqueous matrices, similar in theory to solid phase microextraction (SPME). SBSE has been successfully used to analyze several organic compounds, including food matrices. When compared with SPME, ...

  10. Magnetic multiwall carbon nanotubes modified with dual hydroxy functional ionic liquid for the solid-phase extraction of protein.

    PubMed

    Chen, Jing; Wang, Yuzhi; Huang, Yanhua; Xu, Kaijia; Li, Na; Wen, Qian; Zhou, Yigang

    2015-05-21

    A novel adsorbent based on silica-coated magnetic multiwall carbon nanotubes (MWCNTs) surface modified by dual hydroxy functional ionic liquid (FIL) ([OH]-FIL-m-MWCNTs@SiO2) has been designed and used for the purification of lysozyme (Lys) by magnetic solid-phase extraction (MSPE). Fourier transform infrared spectroscopy (FTIR), a vibrating sample magnetometer (VSM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were employed to characterize [OH]-FIL-m-MWCNTs@SiO2. After extraction, the concentration of Lys was determined by a UV-Vis spectrophotometer at 278 nm. A series of single-factor experiments were carried out to identify the optimal conditions of the extraction and the extraction amount could reach up to 94.6 mg g(-1). The RSD of the precision, the repeatability and the stability experiments were 0.37% (n = 3), 0.47% (n = 3) and 0.52% (n = 3), respectively. Comparison of [OH]-FIL-m-MWCNTs@SiO2 with silica-coated magnetic Fe3O4 (Fe3O4@SiO2), silica-coated magnetic multiwall carbon nanotubes (m-MWCNTs@SiO2) and alkyl quaternary ammonium ionic liquid-modified on m-MWCNTs@SiO2 was carried out by extracting Lys. The extraction of bovine serum albumin (BSA), trypsin (Try) and ovalbumin (OVA) was also done by the proposed method. Desorption of Lys was carried out by 0.005 mol L(-1) Na2HPO4-1 mol L(-1) NaCl as the eluent solution and the desorption ratio reached 91.6%. Nearly 97.8% of the [OH]-FIL-m-MWCNTs@SiO2 could be recovered from each run, and the extraction amount decreased less after five runs. The circular dichroism spectral experiment analysis indicated that the secondary structure of Lys was unchanged after extraction. PMID:25826781

  11. Magnetic graphene oxide modified with choline chloride-based deep eutectic solvent for the solid-phase extraction of protein.

    PubMed

    Huang, Yanhua; Wang, Yuzhi; Pan, Qi; Wang, Ying; Ding, Xueqin; Xu, Kaijia; Li, Na; Wen, Qian

    2015-06-01

    Four kinds of green deep eutectic solvents (DESs) based on choline chloride (ChCl) have been synthesized and coated on the surface of magnetic graphene oxide (Fe3O4@GO) to form Fe3O4@GO-DES for the magnetic solid-phase extraction of protein. X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Fourier transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FESEM) and thermal gravimetric analysis (TGA) were employed to characterize Fe3O4@GO-DES, and the results indicated the successful preparation of Fe3O4@GO-DES. The UV-vis spectrophotometer was used to measure the concentration of protein after extraction. Single factor experiments proved that the extraction amount was influenced by the types of DESs, solution temperature, solution ionic strength, extraction time, protein concentration and the amount of Fe3O4@GO-DES. Comparison of Fe3O4@GO and Fe3O4@GO-DES was carried out by extracting bovine serum albumin, ovalbumin, bovine hemoglobin and lysozyme. The experimental results showed that the proposed Fe3O4@GO-DES performs better than Fe3O4@GO in the extraction of acidic protein. Desorption of protein was carried out by eluting the solid extractant with 0.005 mol L(-1) Na2HPO4 contained 1 mol L(-1) NaCl. The obtained elution efficiency was about 90.9%. Attributed to the convenient magnetic separation, the solid extractant could be easily recycled. PMID:26002214

  12. High performance liquid chromatography for quantification of gatifloxacin in rat plasma following automated on-line solid phase extraction.

    PubMed

    Tasso, Leandro; Dalla Costa, Teresa

    2007-05-01

    An automated system using on-line solid phase extraction and HPLC with fluorimetric detection was developed and validated for quantification of gatifloxacin in rat plasma. The extraction was carried out using C(18) cartridges (BondElut), with a high extraction yield. After washing, gatifloxacin was eluted from the cartridge with mobile phase onto a C(18) HPLC column. The mobile phase consisted of a mixture of phosphoric acid (2.5mM), methanol, acetonitrile and triethylamine (64.8:15:20:0.2, v/v/v/v, apparent pH(app.) 2.8). All samples and standard solutions were chromatographed at 28 degrees C. The method developed was selective and linear for drug concentrations ranging between 20 and 600 ng/ml. Gatifloxacin recovery ranged from 95.6 to 99.7%, and the limit of quantification was 20 ng/ml. The intra and inter-assay accuracy were up to 94.3%. The precision determined not exceed 5.8% of the CV. High extraction yield up to 95% was obtained. Drug stability in plasma was shown in freezer at -20 degrees C up to 1 month, after three freeze-thaw cycles and for 24h in the autosampler after processing. The assay has been successfully applied to measure gatifloxacin plasma concentrations in pharmacokinetic study in rats. PMID:17403594

  13. Micro-solid-phase extraction of organochlorine pesticides using porous metal-organic framework MIL-101 as sorbent.

    PubMed

    Huang, Zhenzhen; Lee, Hian Kee

    2015-07-01

    In this study, a metal-organic framework material, MIL-101, used as a micro-solid-phase extraction (μ-SPE) sorbent for efficient enrichment of five organochlorine pesticides (OCPs), including α-HCH, Aldrin, α-Chlordane, Dieldrin and p,p'-DDD from water samples, followed by gas chromatography-mass spectrometry, is reported. This study demonstrated a new application of MIL-101 using μ-SPE, an advantage of the latter being its ability to process complex aqueous matrices, due to the protection of the sorbent afforded by the hollow fiber membrane bag. Key factors affecting extraction efficiency were studied, including elution solvent, extraction and desorption time. Under the optimal extraction conditions, the calibration plots were linear from 0.05 to 50 ng/mL for α-HCH and p,p'-DDD, and 0.1 to 50 ng/mL for the other three analytes. The limits of detection were between 0.0025 and 0.016 ng/mL. The relative recoveries of the OCPs spiked into real water samples (at 5 ng/mL of each analyte) ranged from 87.6 to 98.6% with relative standard deviations of <10%. PMID:25987299

  14. Development of a new analytical method for the determination of red beetroot betalains using dispersive solid-phase extraction.

    PubMed

    Sawicki, Tomasz; Surma, Magdalena; Zieliński, Henryk; Wiczkowski, Wiesław

    2016-08-01

    The objective of this study was to develop a method for the determination of red beetroot betalains based on the dispersive solid-phase extraction and modified QuEChERS methods followed by micro-high performance liquid chromatography coupled with a mass spectrometer that was equipped with a quadrupole and time-of-flight detector. Currently, new techniques for the extraction of the pigments are necessary and in this study, an extraction of beetroot betalains based on the QuEChERS method was developed for the first time. Twelve variants of the methods with different sorbent combinations were tested. The extraction with 15% methanol and with 0.05% formic acid was performed as a reference method to compare the obtained results. In all of the samples with the addition of sorbents, a lower noise was demonstrated in the obtained results. The betalain concentrations obtained using the tested methods were 0.32-0.54 mg g(-1) , while the value of the reference method was 0.44 mg g(-1) . The method that used the strong ion exchange sorbent (0.44±0.05 mg g(-1) ) was the most adequate in terms of analyzed content, related standard deviation value and interference compared to the reference method. It was concluded that the properly modified QuEChERS method can be successfully applied for the determination of red beetroot betalains. PMID:27273972

  15. Determination of trapidil in human serum and urine by derivative UV spectrophotometry after selective solid-phase extraction.

    PubMed

    Ragno, Gaetano; Risoli, Antonella; De Luca, Michele; Ioele, Giuseppina; Oliverio, Filomena

    2007-10-01

    A novel analytical technique able to determine the anti-ischemic drug trapidil in human serum and urine is proposed. In order to achieve satisfactory sensitivity and selectivity, an extraction procedure was required to isolate the drug from complex matrixes such as serum and urine. A solid-phase extraction procedure was investigated to both increase the analyte concentration and eliminate the interfering molecules present in large amounts in both matrixes. Optimization of the extraction step was realized by selecting a new polymeric sorbent based on a surface-modified styrene-divinylbenzene polymer which provided fast and efficient drug extraction. Drug quantification was performed by using the third-order derivative spectra of the SPE eluates. Absorbance specific signals at (3)D(335,316) and (3)D(316) nm for urine and serum, respectively, were demonstrated to be directly proportional to drug concentration and barely affected by residual matrix interferences. Under the optimized experimental conditions the calibration plots were linear over the concentration range 0.2-50 microg mL(-1). The method was validated by analysis of a series of spiked samples. Accuracy (recovery of 95 and 94% for serum and urine, respectively) and precision (RSD below 4%) were good. PMID:17676316

  16. Magnetic solid phase extraction and static headspace gas chromatography-mass spectrometry method for the analysis of polycyclic aromatic hydrocarbons.

    PubMed

    Cai, Ying; Yan, Zhihong; Wang, Lijia; NguyenVan, Manh; Cai, Qingyun

    2016-01-15

    A magnetic solid phase extraction (MSPE) protocol combining a static headspace gas chromatography coupled to mass spectrometry (HS-GC-MS) method has been developed for extraction, and determination of 16 polycyclic aromatic hydrocarbons (PAHs) in drinking water samples. Magnetic nanoparticles (MNPs) were coated with 3-aminopropyltriethoxysilane and modified by cholesterol chloroformate. Transmission electron microscope, vibrating sample magnetometer, Fourier transform infrared spectrometry and X-ray photoelectron spectroscopy were used to characterize the cholesterol-functionalized sorbents, and the main parameters affecting the extraction as well as HS sampling, such as sorbent amount, extraction time, oven temperature and equilibration time have been investigated and established. Combination with HS sampling, the MSPE procedure was simple, fast and environmentally friendly, without need of any organic solvent. Method validation proved the feasibility of the developed sorbents for the quantitation of the investigated analytes at trace levels obtaining the limit of detection (S/N=3) ranging from 0.20 to 7.8 ng/L. Good values for intra and inter-day precision were obtained (RSDs ≤ 9.9%). The proposed method was successfully applied to drinking water samples. PMID:26724892

  17. Iron oxide functionalized graphene nano-composite for dispersive solid phase extraction of chemical warfare agents from aqueous samples.

    PubMed

    Chinthakindi, Sridhar; Purohit, Ajay; Singh, Varoon; Tak, Vijay; Goud, D Raghavender; Dubey, D K; Pardasani, Deepak

    2015-05-15

    Present study deals with the preparation and evaluation of graphene based magnetic nano-composite for dispersive solid phase extraction of Chemical Weapons Convention (CWC) relevant chemicals from aqueous samples. Nano-composite, Fe3O4@SiO2-G was synthesized by covalently bonding silica coated Fe3O4 onto the graphene sheets. Nerve agents (NA), Sulfur mustard (SM) and their non-toxic environmental markers were the target analytes. Extraction parameters like amount of sorbent, extraction time and desorption conditions were optimized. Dispersion of 20 milligram of sorbent in 200mL of water sample for 20min. followed by methanol/chloroform extraction produced average to good recoveries (27-94%) of targeted analytes. Recoveries of real agents exhibited great dependency upon sample pH and ionic strength. Sarin produced maximum recovery under mild acidic conditions (56% at pH 5) while VX demanded alkaline media (83% at pH 9). Salts presence in the aqueous samples was found to be advantageous, raising the recoveries to as high as 94% for SM. Excellent limits of detection (LOD) for sulphur mustard and VX (0.11ngmL(-1) and 0.19ngmL(-1) respectively) proved the utility of the developed method for the off-site analysis of CWC relevant chemicals. PMID:25828545

  18. Application of mesoporous carbon as a solid-phase microextraction fiber coating for the extraction of volatile aromatic compounds.

    PubMed

    Zhang, Xi; Zang, Xiaohuan; Zhang, Guijiang; Wang, Chun; Wang, Zhi

    2015-08-01

    A mesoporous carbon was fabricated using MCM-41 as a template and sucrose as a carbon source. The carbon material was coated on stainless-steel wires by using the sol-gel technique. The prepared solid-phase microextraction fiber was used for the extraction of five volatile aromatic compounds (chlorobenzene, ethylbenzene, o-xylene, bromobenzene, and 4-chlorotoluene) from tea beverage samples (red tea and green tea) prior to gas chromatography with mass spectrometric detection. The main experimental parameters affecting the extraction of the volatile aromatic compounds by the fiber, including the extraction time, sample volume, extraction temperature, salt addition, and desorption conditions, were investigated. The linearity was observed in the range from 0.1 to 10.0 μg/L with the correlation coefficients (r) ranging from 0.9923 to 0.9982 and the limits of detection were less than 10.0 ng/L. The recoveries of the volatile aromatic compounds by the method from tea beverage samples at spiking levels of 1.0 and 10.0 μg/L ranged from 73.1 to 99.1%. PMID:26041569

  19. Sulfonated nanocellulose for the efficient dispersive micro solid-phase extraction and determination of silver nanoparticles in food products.

    PubMed

    Ruiz-Palomero, Celia; Soriano, M Laura; Valcárcel, Miguel

    2016-01-01

    This paper reports a simple approach to Analytical Nanoscience and Nanotechnology (AN&N) that integrates the nanotool, sulfonated nanocellulose (s-NC), and nanoanalyte, silver nanoparticles (AgNPs), in the same analytical process by using an efficient, environmentally friendly dispersive micro solid-phase extraction (D-μSPE) capillary electrophoresis (CE) method with s-NC as sorbent material. Introducing negatively charged sulfate groups onto the surface of cellulose enhances its surface chemistry and enables the extraction and preconcentration of AgNPs of variable diameter (10, 20 and 60nm) and shell composition (citrate and polyvinylpyrrolidone coatings) from complex matrices into a cationic surfactant. In this way, AgNPs of diverse nature were successfully extracted onto the s-NC sorbent and then desorbed into an aqueous solution containing thiotic acid (TA) prior to CE without the need for any labor-intensive cleanup. The ensuing eco-friendly D-μSPE method exhibited a linear response to AgNPs with a limit of detection (LOD) of 20μg/L. Its ability to specifically recognize AgNPs of different sizes was checked in orange juice and mussels, which afforded recoveries of 70.9-108.4%. The repeatability of the method at the limit of quantitation (LOQ) level was 5.6%. Based on the results, sulfonated nanocellulose provides an efficient, cost-effective analytical nanotool for the extraction of AgNPs from food products. PMID:26116191

  20. Simultaneous determination of phenolic compounds in Equisetum palustre L. by ultra high performance liquid chromatography with tandem mass spectrometry combined with matrix solid-phase dispersion extraction.

    PubMed

    Wei, Zuofu; Pan, Youzhi; Li, Lu; Huang, Yuyang; Qi, Xiaolin; Luo, Meng; Zu, Yuangang; Fu, Yujie

    2014-11-01

    A method based on matrix solid-phase dispersion extraction followed by ultra high performance liquid chromatography with tandem mass spectrometry is presented for the extraction and determination of phenolic compounds in Equisetum palustre. This method combines the high efficiency of matrix solid-phase dispersion extraction and the rapidity, sensitivity, and accuracy of ultra high performance liquid chromatography with tandem mass spectrometry. The influential parameters of the matrix solid-phase dispersion extraction were investigated and optimized. The optimized conditions were as follows: silica gel was selected as dispersing sorbent, the ratio of silica gel to sample was selected to be 2:1 (400/200 mg), and 8 mL of 80% methanol was used as elution solvent. Furthermore, a fast and sensitive ultra high performance liquid chromatography with tandem mass spectrometry method was developed for the determination of nine phenolic compounds in E. palustre. This method was carried out within <6 min, and exhibited satisfactory linearity, precision, and recovery. Compared with ultrasound-assisted extraction, the proposed matrix solid-phase dispersion procedure possessed higher extraction efficiency, and was more convenient and time saving with reduced requirements on sample and solvent amounts. All these results suggest that the developed method represents an excellent alternative for the extraction and determination of active components in plant matrices. PMID:25132205

  1. Magnetic nanoparticles with hydrophobicity and hydrophilicity for solid-phase extraction of polycyclic aromatic hydrocarbons from environmental water samples.

    PubMed

    Xue, Shu-Wen; Tang, Min-Qiong; Xu, Li; Shi, Zhi-guo

    2015-09-11

    Magnetic nanoparticles (MNPs) featured with divinylbenzene (DVB) and sulfonate functionalities (Fe3O4-DVB-SO3(-)) were prepared via "thiol-ene" click chemistry. The hydrophobic DVB moieties were dedicated for extraction while the hydrophilic sulfonate groups were designed for dispersing the MNPs in aqueous sample solution. Thus, the specially designed material could ensure operational convenience and improve reproducibility during extraction. The application of the material was demonstrated by the extraction of polycyclic aromatic hydrocarbons (PAHs) from environmental water samples followed by gas chromatography-mass spectrometric analysis. The main factors influencing the extraction, including the type of the desorption solvent, the agitation mode, the amount of MNPs, extraction and desorption time and salt addition in sample solution, were investigated in detail. Under the optimized conditions, the proposed method showed satisfactory reproducibility with intra-day and inter-day relative standard deviations less than 16.5% and 21.2%, and low limits of detection of 1.1pgmL(-1), 0.8pgmL(-1), 1.1pgmL(-1), 1.4pgmL(-1), 0.6pgmL(-1), 2.1pgmL(-1) and 0.7pgmL(-1) for naphthalene, acenaphthene, fluorine, phenanthrene, anthracene, fluoranthene and pyrene, respectively. The developed method was also successfully used for determination of the PAHs in genuine lake and river environmental water samples by standard addition method. All the studied PAHs were detected in these waters with comparable results by the standard liquid-liquid extraction method. The developed MNPs with dual property of hydrophobicity and hydrophilicity were suitable for the treatment of water samples. The magnetic solid phase extraction based on this material was reliable and convenient. It has great potential in the preconcentration of trace analytes in complex matrix. PMID:26260841

  2. A solid-phase extraction method for rapidly determining the adsorption coefficient of pharmaceuticals in sewage sludge.

    PubMed

    Berthod, Laurence; Roberts, Gary; Whitley, David C; Sharpe, Alan; Mills, Graham A

    2014-12-15

    The partitioning of pharmaceuticals in the environment can be assessed by measuring their adsorption coefficients (Kd) between aqueous and solid phases. Measuring this coefficient in sewage sludge gives an indication of their partitioning behaviour in a wastewater treatment plant and hence contributes to an understanding of their subsequent fate. The regulatory approved method for measuring Kd in sewage sludge is the US Environmental Protection Agency's Office of Prevention, Pesticides and Toxic Substances (OPPTS) guideline 835.1110, which is labour intensive and time consuming. We describe an alternative method for measuring the Kd of pharmaceuticals in sewage sludge using a modified solid-phase extraction (SPE) technique. SPE cartridges were packed at different sludge/PTFE ratios (0.4, 6.0, 24.0 and 40.0% w/w sludge) and eluted with phosphate buffer at pH 7.4. The approach was tested initially using three pharmaceuticals (clofibric acid, diclofenac and oxytetracycline) that covered a range of Kd values. Subsequently, the sorption behaviour of ten further pharmaceuticals with varying physico-chemical properties was evaluated. Results from the SPE method were comparable to those of the OPPTS test, with a correlation coefficient of 0.93 between the two approaches. SPE cartridges packed with sludge and PTFE were stable for up to one year; use within one month reduced variability in measurements (to a maximum of 0.6 log units). The SPE method is low-cost, easy to use and enables the rapid measurement of Kd values for a large number of chemicals. It can be used as an alternative to the more laborious full OPPTS test in environmental fate studies and risk assessments. PMID:25299795

  3. A solid-phase extraction method for rapidly determining the adsorption coefficient of pharmaceuticals in sewage sludge

    PubMed Central

    Berthod, Laurence; Roberts, Gary; Whitley, David C.; Sharpe, Alan; Mills, Graham A.

    2014-01-01

    The partitioning of pharmaceuticals in the environment can be assessed by measuring their adsorption coefficients (Kd) between aqueous and solid phases. Measuring this coefficient in sewage sludge gives an indication of their partitioning behaviour in a wastewater treatment plant and hence contributes to an understanding of their subsequent fate. The regulatory approved method for measuring Kd in sewage sludge is the US Environmental Protection Agency's Office of Prevention, Pesticides and Toxic Substances (OPPTS) guideline 835.1110, which is labour intensive and time consuming. We describe an alternative method for measuring the Kd of pharmaceuticals in sewage sludge using a modified solid-phase extraction (SPE) technique. SPE cartridges were packed at different sludge/PTFE ratios (0.4, 6.0, 24.0 and 40.0% w/w sludge) and eluted with phosphate buffer at pH 7.4. The approach was tested initially using three pharmaceuticals (clofibric acid, diclofenac and oxytetracycline) that covered a range of Kd values. Subsequently, the sorption behaviour of ten further pharmaceuticals with varying physico-chemical properties was evaluated. Results from the SPE method were comparable to those of the OPPTS test, with a correlation coefficient of 0.93 between the two approaches. SPE cartridges packed with sludge and PTFE were stable for up to one year; use within one month reduced variability in measurements (to a maximum of 0.6 log units). The SPE method is low-cost, easy to use and enables the rapid measurement of Kd values for a large number of chemicals. It can be used as an alternative to the more laborious full OPPTS test in environmental fate studies and risk assessments. PMID:25299795

  4. Determination of Cremophor EL in plasma after sample preparation with solid phase extraction and plasma protein precipitation.

    PubMed

    Meyer, T H; Böhler, J; Frahm, A W

    2001-01-01

    The non-ionic emulsifier Cremophor EL can be quantified using a special potentiometric titration technique with barium chloride activation and precipitation with sodium tetraphenylborate. The end point of the titration is indicated by an ionsensitive coated wire electrode which responds to an excess of tetraphenylborate ions. Sample preparation is necessary to quantify the excipient in plasma of patients receiving ciclosporin formulations with Cremophor EL (Sandimmun), since plasma proteins cause disturbances of the titration. Solid phase extraction was tested with various sorbent materials. Although some of the sorbents yielded good extraction rates of Cremophor EL from aqueous solutions, the extraction rates from plasma were significantly lower. Therefore, plasma protein precipitation with acetonitrile has been examined as an alternative to SPE and has been proved the superior method. Using the precipitation technique, a recovery rate of above 90% was achieved. Furthermore, the limit of detection from plasma was found to be 30 microg, in analogy to the determination from aqueous solutions. The combination of the plasma protein precipitation with the potentiometric titration allows quantitation and thus pharmakokinetic investigations of Cremophor EL in patients treated with Sandimmun after kidney-transplantation. PMID:11199229

  5. Quantitation of promethazine and metabolites in urine samples using on-line solid-phase extraction and column-switching

    NASA Technical Reports Server (NTRS)

    Song, Q.; Putcha, L.; Harm, D. L. (Principal Investigator)

    2001-01-01

    A chromatographic method for the quantitation of promethazine (PMZ) and its three metabolites in urine employing on-line solid-phase extraction and column-switching has been developed. The column-switching system described here uses an extraction column for the purification of PMZ and its metabolites from a urine matrix. The extraneous matrix interference was removed by flushing the extraction column with a gradient elution. The analytes of interest were then eluted onto an analytical column for further chromatographic separation using a mobile phase of greater solvent strength. This method is specific and sensitive with a range of 3.75-1400 ng/ml for PMZ and 2.5-1400 ng/ml for the metabolites promethazine sulfoxide, monodesmethyl promethazine sulfoxide and monodesmethyl promethazine. The lower limits of quantitation (LLOQ) were 3.75 ng/ml with less than 6.2% C.V. for PMZ and 2.50 ng/ml with less than 11.5% C.V. for metabolites based on a signal-to-noise ratio of 10:1 or greater. The accuracy and precision were within +/- 11.8% in bias and not greater than 5.5% C.V. in intra- and inter-assay precision for PMZ and metabolites. Method robustness was investigated using a Plackett-Burman experimental design. The applicability of the analytical method for pharmacokinetic studies in humans is illustrated.

  6. Analytical method of measuring tea catechins in human plasma by solid-phase extraction and HPLC with electrochemical detection.

    PubMed

    Umegaki, K; Sugisawa, A; Yamada, K; Higuchi, M

    2001-12-01

    We developed an analytical method for measuring tea catechins in plasma by solid-phase extraction (SPE), followed by HPLC with a coulometric electrochemical detector. The plasma was mixed with an equal volume of acetonitrile to precipitate protein, and catechins in the resulting supernatant were extracted by SPE, using a C18 cartridge. To correct the extraction efficiency, ethyl gallate was simultaneously added with acetonitrile as an internal standard. Plasma samples were treated in microtubes, and evaporation and SPE were performed by the use of a vacuum centrifuge and vacuum manifold for SPE. The use of these instruments allowed the handling of a large number of samples simultaneously. In this method, (-)-epicatechin (EC), (-)-epicatechin-3-O-gallate (ECg), (-)-epigallocatechin (EGC), (-)-epigallocatechin-3-O-gallate (EGCg), and ethyl gallate could be detected as a single peak with high sensitivity. For an analysis of the conjugated form of catechins, plasma samples were treated with glucuronidase and sulfatase. Type H-2 beta-glucuronidase effectively digested the conjugated forms, and the enzyme also converted EGCg and ECg to their nongallated form. When the concentrations of catechins in plasma were analyzed in subjects who took a single dose of catechin liquid, the concentration of free EGCg in plasma reached a maximum of 300 nM at 1 h after intake; those of the other free form of catechins increased only slightly after the intake. The concentration of total catechins (free+conjugated forms) in plasma increased up to 2 h after the intake. PMID:11922115

  7. Pesticide residue analysis in cereal-based baby foods using multi-walled carbon nanotubes dispersive solid-phase extraction.

    PubMed

    González-Curbelo, Miguel Angel; Asensio-Ramos, María; Herrera-Herrera, Antonio V; Hernández-Borges, Javier

    2012-07-01

    In the present study, a new analytical method has been developed for the simultaneous quantification of 15 organophosphorus pesticides, including some of their metabolites, (disulfoton-sulfoxide, ethoprophos, cadusafos, dimethoate, terbufos, disulfoton, chlorpyrifos-methyl, malaoxon, fenitrothion, pirimiphos-methyl, malathion, chlorpyrifos, terbufos-sulfone, disulfoton-sulfone and fensulfothion) in three different types of commercial cereal-based baby foods. Dispersive solid-phase extraction (dSPE) with multi-walled carbon nanotubes (MWCNTs) was used together with gas chromatography with nitrogen phosphorus detection. Most favorable conditions involved a previous ultrasound-assisted extraction of the sample with acetonitrile containing formic acid. After evaporation of the extract and redissolution in water, a dSPE procedure was carried out with MWCNTs. The whole method was validated in terms of repeatability, linearity, precision and accuracy and matrix effect was also evaluated. Absolute recoveries were in the range 64-105 % with relative standard deviation values below 7.6 %. Limits of quantification achieved ranged from 0.31 to 5.50 μg/kg, which were lower than the European Union maximum residue limits for pesticide residues in cereal-based baby foods. PMID:22623047

  8. N-methylimidazolium modified magnetic particles as adsorbents for solid phase extraction of genomic deoxyribonucleic acid from genetically modified soybeans.

    PubMed

    Deng, Manchen; Jiang, Cheng; Jia, Li

    2013-04-10

    N-Methylimidazolium modified magnetic particles (MIm-MPs) were prepared and applied in the solid phase extraction of genomic deoxyribonucleic acid (DNA) from genetically modified soybeans. The adsorption of MIm-MPs for DNA mainly resulted from the strong electrostatic interaction between the positively charged MPs and the negatively charged DNA. The elution of DNA from MPs-DNA conjugates using phosphate buffer resulted from the stronger electrostatic interaction of phosphate ions with MPs than DNA. In the extraction procedure, no harmful reagents (e.g. phenol, chloroform and isopropanol, etc.) used, high yield (10.4 μg DNA per 30 mg sample) and high quality (A260/A280=1.82) of DNA can be realized. The as-prepared DNA was used as template for duplex-polymerase chain reaction (PCR) and the PCR products were analyzed by a sieving capillary electrophoresis method. Quick and high quality extraction of DNA template, and fast and high resolution detection of duplex PCR products can be realized using the developed method. No toxic reagents are used throughout the method. PMID:23522109

  9. Using pollen grains as novel hydrophilic solid-phase extraction sorbents for the simultaneous determination of 16 plant growth regulators.

    PubMed

    Lu, Qian; Wu, Jian-Hong; Yu, Qiong-Wei; Feng, Yu-Qi

    2014-11-01

    In this article, pollen grains were for the first time used as a hydrophilic solid-phase extraction (HILIC-SPE) sorbent for the determination of 16 plant growth regulators (PGRs) in fruits and vegetables. Fourier transform infrared spectroscopy (FT-IR), scanning electronic microscopy (SEM) and nitrogen sorption porosimetry (NSP) were used to investigate the chemical structure and the surface properties of the pollen grains. Pollen grains exhibited an excellent adsorption capacity for some polar compounds due to their particular functional groups. Several parameters influencing extraction performance were investigated. A green and simple HILIC-SPE-method using pollen grain cartridge for purification of fruit and vegetable extractions, followed by ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry (UHPLC-MS/MS) was established. Good linear relationships were obtained for 16 PGRs with correlation coefficients (R) above 0.9980. The limits of detection (LODs) of 16 PGRs in cucumber were in the range of 0.01-1.10 μg · kg(-1). Reproducibility of the method was evaluated by intra-day and inter-day precisions with relative standard deviations (RSDs), which were less than 14.4%. We successfully applied this methodology to analyze 16 PGRs in 8 different kinds of fruits and vegetables. The recoveries from samples spiked with 16 PGRs were from 80.5% to 119.2%, with relative standard deviations less than 15.0%. PMID:25311486

  10. Chitosan-poly(m-phenylenediamine)@Fe₃O₄ nanocomposite for magnetic solid-phase extraction of polychlorinated biphenyls from water samples.

    PubMed

    Liao, Qie Gen; Wang, Dong Gen; Luo, Lin Guang

    2014-11-01

    A extraction medium based on chitosan-poly(m-phenylenediamine) (CS-PPD) @Fe3O4 nanocomposite was synthesized by chemical polymerization of m-phenylenediamine in the presence of chitosan coated magnetic nanocomposite, and for the first time, used as the sorbent for the magnetic solid-phase extraction (MSPE) of seven polychlorinated biphenyls (PCB28, PCB52, PCB101, PCB118, PCB138, PCB153, and PCB180) at trace levels in water samples. Gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) was used for PCBs quantification and detection. Several factors related to MSPE efficiencies, such as type and amount of sorbent, extraction time, sample pH, and desorption conditions were investigated. Under the optimized conditions, an excellent linearity was observed in the range of 1.0-200 ng L(-1) for PCB180, 0.5-200 ng L(-1) for the other six PCBs with the correlation coefficients ranging from 0.9954 to 0.9993. The good recoveries at spiked levels of 10.0, 20.0, and 50.0 ng L(-1) were obtained in the range of 94%-108%, and the coefficients of variations were less than 6%. The proposed method was feasible, rapid, and easy to operate for the trace analysis of the PCBs in local aquaculture water, livestock breeding water, and sewage water samples. PMID:25342296

  11. Matrix solid-phase dispersion extraction of organophosphorus pesticide using SiO2-poly(N-vinylimidazole)

    NASA Astrophysics Data System (ADS)

    Gutiérrez-Solís, M. C.; Muñoz-Rodríguez, D.; Medina-Peralta, S.; Carrera-Figueiras, C.; Ávila-Ortega, A.

    2013-06-01

    A sorbent material based on silica particles modified with poly(N-vinylimidazole) (SiO2-PVI) has been evaluated for the treatment of samples by matrix solid-phase dispersion (MSPD). The extraction of four organophosphorus pesticides was done from a spiked tomato and the extracts were analyzed by gas chromatography coupled to mass spectrometry. Six elution solvents were evaluated and acetone was selected due to better recovery of the four pesticides and low background signal in the chromatograms. A factorial design 24 was used for selection of extraction conditions. The factors were contact time, acetone volume, treatment (with or without freeze-drying) and adsorbent (SiO2 or SiO2-PVI). The best recoveries were obtained using 15 minutes of contact, 2 mL of solvent and sorbent without freeze-drying. The recoveries were between 60 and 83% for SiO2-PVI in spiked tomato with 0.2 and 0.8μg/g.

  12. Determination of five nitrobenzoic acids in groundwater by solid-phase extraction and liquid chromatography-mass spectrometry.

    PubMed

    Ma, Wai-Tang; Chan, Wan; Steinbach, Klaus; Cai, Zongwei

    2007-03-01

    A method involving solid-phase extraction (SPE) and reversed-phase liquid chromatography-mass spectrometry (LC-MS) has been developed for determination, in groundwater, of nitrobenzoic acids associated with 2,4,6-trinitrotoluene production. Pre-concentration on a co-polymer-based SPE cartridge enabled quantitative extraction of the analytes from water. Investigation of negative ion electrospray and atmospheric-pressure chemical ionization mass spectrometry indicated the sensitivity of APCI was more than twice that of ESI. An 15N-labeled internal standard was used to achieve more accurate quantitation and mass assignment. Recovery was better than 80% when 10 mL water was extracted with the SPE cartridge. Combination of SPE with LC-MS analysis resulted in method detection limits of less than 5 microg L-1. The method has been used for analysis of groundwater samples collected from a site of a former ammunition plant. Contamination with nitrobenzoic acids was determined at microg L-1 levels. PMID:17203256

  13. Novel solid-phase membrane tip extraction and gas chromatography with mass spectrometry methods for the rapid analysis of triazine herbicides in real waters.

    PubMed

    Sanagi, Mohd Marsin; Muhammad, Sarmad S; Hussain, Iqbal; Ibrahim, Wan Aini Wan; Ali, Imran

    2015-02-01

    Novel, fast, selective, eco-friendly and reproducible solid-phase membrane tip extraction and gas chromatography with mass spectrometry methods were developed and validated for the analysis of triazine herbicides (atrazine and secbumeton) in stream and lake waters. The retention times of atrazine and secbumeton were 7.48 and 8.51 min. The solid-phase membrane tip extraction was carried out in semiautomated dynamic mode on multiwall carbon nanotubes enclosed in a cone-shaped polypropylene membrane cartridge. Acetone and methanol were found as the best preconditioning and desorption solvents, respectively. The extraction and desorption times for these herbicides were 15.0 and 10.0 min, respectively. The percentage recoveries of atrazine and secbumeton were 88.0 and 99.0%. The linearity range was 0.50-80.0 μg/L (r(2) > 0.994), with detection limits (<0.47 μg/L, S/N = 3) and good reproducibility (<8.0%). The ease of operation, eco-friendly nature, and low cost of solid-phase membrane tip extraction made these methods novel. The Solid-phase membrane tip extraction method was optimized by considering the effect of extraction time, desorbing solvents and time. PMID:25421899

  14. [Development of Determination Method of Fluoroquinolone Antibiotics in Sludge Based on Solid Phase Extraction and HPLC-Fluorescence Detection Analysis].

    PubMed

    Dai, Xiao-hu; Xue, Yong-gang; Liu, Hua-jie; Dai, Ling-ling; Yan, Han; Li, Ning

    2016-04-15

    Fluoroquinolone antibiotics (FQs), as the common pharmaceuticals and personal care products (PPCPs), are widespread in the environment. FQs contained in wastewater would be ultimately enriched in sludge, posing a potential threat to the consequent sludge utilization. To optimize the analytical method applicable to the determination of FQs in sludge, the authors selected ofloxacin (OFL), norfioxacin (NOR), ciprofloxacin (CIP) and lomefloxacin (LOM) as the target FQs, and established a method which was based on cell lysis, FQs extraction with triethylamine/methanol/water solution, Solid Phase Extraction (SPE) and HPLC-Fluorescence Detection (FLD) determination. After the investigation, phosphoric acid-triethylamine was decided to be the buffer salt, and methanol was chosen as the organic mobile phase. The gradient fluorescence scanning strategy was proved to be necessary for the optimal detection as well. Furthermore, by the designed orthogonal experiments, the effects of the extraction materials, pH, and the eluents on the efficiency of SPE extraction were evaluated, by which the optimal extraction conditions were determined. As a result, FQs in liquid samples could be analyzed by utilizing HLB extraction cartridge, and the recovery rates of the four FQs were in the range of 82%-103%. As for solid samples, the recovery rates of the four FQs contained reached up to 71%-101%. Finally, the adsorptivity of the sludge from the different tanks ( anaerobic, anoxic and oxic tanks) was investigated, showing gradual decrease in the adsorption capacity, but all adsorbed over 90% of the EQs. This conclusion also confirmed that 50% removal of FQs in the domestic wastewater treatment plant was realized by sludge adsorption. PMID:27548982

  15. Detection of urinary creatinine using gold nanoparticles after solid phase extraction

    NASA Astrophysics Data System (ADS)

    Sittiwong, Jarinya; Unob, Fuangfa

    2015-03-01

    Label-free gold nanoparticles (AuNPs) were utilized in the detection of creatinine in human urine after a sample preparation by extraction of creatinine on sulfonic acid functionalized silica gel. With the proposed sample preparation method, the interfering effects of the urine matrix on creatinine detection by AuNPs were eliminated. Parameters affecting creatinine extraction were investigated. The aggregation of AuNPs induced by creatinine resulted in a change in the surface plasmon resonance signal with a concomitant color change that could be observed by the naked eye and quantified spectrometrically. The effect of AuNP concentration and reaction time on AuNP aggregation was investigated. The method described herein provides a determination of creatinine in a range of 15-40 mg L-1 with a detection limit of 13.7 mg L-1 and it was successfully used in the detection of creatinine in human urine samples.

  16. Application of magnetic hydroxyapatite nanoparticles for solid phase extraction of plasmid DNA.

    PubMed

    Shan, Zhi; Li, Xianghai; Gao, Yaying; Wang, Xianxiang; Li, Chenglei; Wu, Qi

    2012-06-15

    We developed a facile method for plasmid DNA (pDNA) extraction from crude Escherichia coli lysate using magnetic hydroxyapatite nanoparticles (MHapNPs) in the presence of polyethylene glycol (PEG)/NaCl. DNA condensation induced by PEG/NaCl is a prerequisite for achieving pronounced DNA recovery. The quality and quantity of MHapNP-purified pDNA under optimal binding buffer conditions (0.5 volume of 20% PEG 8000/2M NaCl) were comparable to those obtained using organic solvents or commercial kits. This MHapNP technique is rapid, simple, cost-effective, and environmentally friendly and has the potential to extract DNA from other cell lysates. PMID:22465330

  17. Water-compatible molecularly imprinted polymer as a sorbent for the selective extraction and purification of adefovir from human serum and urine.

    PubMed

    Pourfarzib, Mojgan; Dinarvand, Rasoul; Akbari-Adergani, Behrouz; Mehramizi, Ali; Rastegar, Hossein; Shekarchi, Maryam

    2015-05-01

    A molecularly imprinted polymer has been synthesized to specifically extract adefovir, an antiviral drug, from serum and urine by dispersive solid-phase extraction before high-performance liquid chromatography with UV analysis. The imprinted polymers were prepared by bulk polymerization by a noncovalent imprinting method that involved the use of adefovir (template molecule) and functional monomer (methacrylic acid) complex prior to polymerization, ethylene glycol dimethacrylate as cross-linker, and chloroform as porogen. Molecular recognition properties, binding capacity, and selectivity of the molecularly imprinted polymers were evaluated and the results show that the obtained polymers have high specific retention and enrichment for adefovir in aqueous medium. The new imprinted polymer was utilized as a molecular sorbent for the separation of adefovir from human serum and urine. The serum and urine extraction of adefovir by the molecularly imprinted polymer followed by high-performance liquid chromatography showed a linear calibration curve in the range of 20-100 μg/L with excellent precisions (2.5 and 2.8% for 50 μg/L), respectively. The limit of detection and limit of quantization were determined in serum (7.62 and 15.1 μg/L), and urine (5.45 and 16 μg/L). The recoveries for serum and urine samples were found to be 88.2-93.5 and 84.3-90.2%, respectively. PMID:25763883

  18. Quercetin-imprinted polymer for anthocyanin extraction from mangosteen pericarp.

    PubMed

    Piacham, Theeraphon; Isarankura-Na-Ayudhya, Chartchalerm; Prachayasittikul, Virapong

    2015-06-01

    Molecular imprinting is a facilitative technology for the production of artificial receptors possessing great endurance with high specificity toward target molecules of interest. The polymers are commonly applied for separation or analysis of substances of interest. In this study, we prepared molecularly imprinted polymers for the purpose of binding specifically to quercetin and related compounds. Quercetin was used as the template molecule, 4-vinylpyridine (4-VP) as the functional monomer, ethylene glycol dimethacrylate (EDMA) as the cross-linking monomer, azobisisobutyronitrile (AIBN) as the polymerization initiator and ethanol as the porogenic solvent. Such 4-VP-based imprinted polymer was found to bind the template molecule greater than that of the control polymer with an approximate 2 folds higher binding using 20mg of polymer in the optimal solvent, ethanol:water (4:1v/v). Quercetin-imprinted polymer (QIP) was found to bind well against its template; approximately 1mg/g polymer. In addition, QIP was applied to bind anthocyanin from the crude extract of mangosteen pericarp. The binding capacity of quercetin-MIP toward anthocyanin was approximately 0.875mg per gram of polymer. This result indicated that quercetin-MIP showed its specific binding to quercetin and related compound particularly anthocyanin. In conclusion, we have demonstrated the successful preparation and utilization of molecularly imprinted polymer for the specific recognition of quercetin as well as structurally related anthocyanins from the mangosteen pericarp with enhanced and robust performance. PMID:25842116

  19. Application of a molecularly imprinted polymer for the extraction of kukoamine a from potato peels.

    PubMed

    Piletska, Elena V; Burns, Rosemary; Terry, Leon A; Piletsky, Sergey A

    2012-01-11

    A molecularly imprinted polymer (MIP) for the purification of N(1),N(12)-bis(dihydrocaffeoyl)spermine (kukoamine A) was computationally designed and tested. The properties of the polymer were characterized. The protocol of the solid phase extraction (SPE) of kukoamine A from potato peels was optimized. A HPLC-MS method for the quantification of kukoamine A was developed and used for all optimization studies. The capacity of the MIP in relation to kukoamine A from the potato peels extract was estimated at 54 mg/g of the polymer. The kukoamine A purified from potato extract using MIP was exceptionally pure (≈ 90%). Although the corresponding blank polymer was less selective than the MIP for the extraction of kukoamine A from the potato extract, it was shown that the blank polymer could be effectively used for the purification of the crude synthetic kukoamine (polymer capacity = 80 mg of kukoamine A/g of the adsorbent, kukoamine A purity ≈ 86%). Therefore, selective adsorbents could be computationally designed for other plant products, allowing their purification in quantities that would be sufficient for more detailed studies and potential practical applications. PMID:22142260

  20. Innovative separation and preconcentration technique of coagulating homogenous dispersive micro solid phase extraction exploiting graphene oxide nanosheets.

    PubMed

    Ghazaghi, Mehri; Mousavi, Hassan Zavvar; Rashidi, Ali Morad; Shirkhanloo, Hamid; Rahighi, Reza

    2016-01-01

    A uniquely novel, fast, and facile technique is introduced for the first time in which a scant amount of graphene oxide (GO), without modification, has been utilized in dispersive mode of solid phase extraction (SPE) for an efficient yet simple separation. The proposed method of coagulating homogenous dispersive micro solid phase extraction (CHD-µSPE) is based on coagulation of homogeneous GO solution with the aid of polyetheneimine (PEI). CHD-µSPE use full adsorption capacity of GO because in this method was used GO solution obtained from synthesis process without drying step and stacking nanosheets. In optimized condition, 30 µL GO solution (7 mg mL(-1)), obtained in synthesis process, was injected into 1.5 mL the sample solution followed by immediate injection of 53 µL PEI solution (1 mg mL(-1)). After inserting PEI, GO sheets aggregate and can be readily separated by centrifugation. PEI not only cause aggregation of GO, but also form three-dimensional network of GO with easy handling in following separation steps. Lead, cadmium, and chromium were selected as model analytes and the effecting parameters including the amount of GO, concentration of PEI, sample pH, extraction time, and type of desorption solvent were investigated and optimized. The results indicate that the proposed CHD-µSPE method can be successfully applied GO in dispersive mode of SPE without effecting on good capability adsorption of GO. The novel method was applied in determination of lead, cadmium, and chromium in water, human saliva, and urine samples by electrothermal atomic absorption spectrometry. The detection limits are as low as 0.035, 0.005, and 0.012 µg L(-1) for Pb, Cd, and Cr respectively. The intra-day precisions (RSDs) were lower than 3.8%. CHD-µSPE method showed a good linear ranges of 0.24-15.6, 0.015-0.95 and 0.039-2.33 µg L(-1) for Pb, Cd and Cr respectively. Method performance was investigated by determination of mentioned metal ions in river water, human urine and

  1. Development of colorimetric solid phase extraction (C-SPE) for in-flight monitoring of spacecraft water supplies

    NASA Astrophysics Data System (ADS)

    Gazda, Daniel Bryan

    2004-12-01

    Colorimetric solid phase extraction (C-SPE) is a sorption-spectrophotometric technique that combines colorimetric reagents, solid phase extraction, and diffuse reflectance spectroscopy to quantify trace analytes in water samples. In C-SPE, a syringe is used to meter a known volume of sample through a membrane impregnated with a selective colorimetric reagent along with any additives required to optimize the complexation of the reagent and analyte. As the sample is passed through the membrane, analytes are extracted and complexed, leading to a detectable change in the optical characteristics of the membrane. The analyte-reagent complex is then quantified directly on the membrane, using a hand-held diffuse reflectance spectrophotometer. This dissertation focuses on the development, ground testing, and microgravity flight demonstration of C-SPE methods to meet the near- and long-term water quality monitoring needs of NASA. To this end, the ability of C-SPE to function in a microgravity environment was tested through performance evaluations of methods for the determination of the biocidal agents silver(I) and iodine on the KC-135 microgravity simulator. The biocidal iodine platform was investigated further to determine which iodine species is responsible for the C-SPE signal. Through systematic comparisons of C-SPE results and UV-Visible absorbance studies it was determined that biocidally active I2 is the iodine species complexed by poly(vinylpyrrolidone). The application of C-SPE to additional target water quality parameters is demonstrated through the determination of nickel(II), a metal leachate found in archived water samples from the International Space Station, using dimethylglyoxime. This method introduced a new variation of C-SPE, the quantification of trace analytes based on the collection of an insoluble, colored precipitate. The nickel(II) method was then combined with the method for biocidal silver(I) and a new method to measure sample pH to create a

  2. Study and comparison of polydopamine and its derived carbon decorated nanoparticles in the magnetic solid-phase extraction of estrogens.

    PubMed

    Huang, Zhenzhen; Lee, Hian Kee

    2015-10-01

    Surface functionalization enabled by bioinspired polydopamine (PDA) is recognized as a convenient route for fabrication of multifunctional nanoparticles. In the present work, magnetic nanoparticles with polymer (Fe3O4@PDA) and carbon shell (Fe3O4@C) were prepared by self-oxidation of dopamine, and carbonization of the PDA coating. The performance of the two magnetic sorbents in the extraction and determination of four estrogens, estrone (E1), estradiol (E2), estriol (E3) and diethylstilbestrol (DES) from water samples in the form of magnetic solid-phase extraction was investigated. Orthogonal array design was utilized to facilitate the optimization of the proposed sample preparation approach. The highest extraction capabilities of the two sorbents were achieved under different experimental conditions. Fe3O4@PDA was shown to be superior to Fe3O4@C in the enrichment of estrogens, suggesting stronger interactions were established between the PDA coating and the target compounds. The extraction and desorption operations were enabled more conveniently by magnetic separation and the extracts were analyzed by high-performance liquid chromatography coupled with ultraviolet and fluorescence detection. The limits of detection achieved in the proposed method were in the range of 0.072-0.15ng/mL for E1 and DES, and 0.0017-0.0062ng/mL for E2 and E3. Good precision (>0.9995) was obtained with the linearity ranging from 0.2 to 100ng/mL, and from 0.01 to 5ng/mL. The method developed was assessed by analysis of the estrogens in tap water, drain water and bottled mineral water samples. PMID:26341595

  3. Development of natural sorbent based micro-solid-phase extraction for determination of phthalate esters in milk samples.

    PubMed

    Sajid, Muhammad; Basheer, Chanbasha; Alsharaa, Abdulnaser; Narasimhan, Kothandaraman; Buhmeida, Abdelbaset; Al Qahtani, Mohammed; Al-Ahwal, Mahmoud Shaheen

    2016-06-14

    In the present study, a natural sorbent based micro-solid phase extraction (μ-SPE) was developed for determination of phthalate esters in milk samples. For the first time, an efficient and cost effective natural material (seed powder of Moringa oleifera) was employed as sorbent in μ-SPE. The sorbent was found to be naturally enriched with variety of functional groups and having a network of interconnected fibers. This method of extraction integrates different steps such as removal of proteins and fatty stuff, extraction and pre-concentration of target analytes into a single step. Thirteen phthalate esters were selected as target compounds for the development and evaluation of method. Some key parameters affecting the extraction efficiency were optimized, including selection of membrane, selection and amount of sorbent, extraction time, desorption solvent, volume of desorption solvent, desorption time and effect of salt addition. Under the optimum conditions, very good linearity was achieved for all the analytes with coefficient of determinations (R(2)) ranging between 0.9768 and 0.9977. The limits of detection ranged from 0.01 to 1.2 μg L(-1). Proposed method showed satisfactory reproducibility with relative standard deviations ranging from 3.6% to 10.2% (n = 7). Finally, the developed method was applied to tetra pack and bottled milk samples for the determination of phthalate esters. The performance of natural sorbent based μ-SPE was better or comparable to the methods reported in the literature. PMID:27181642

  4. Simultaneous in situ derivatization and ultrasound-assisted dispersive magnetic solid phase extraction for thiamine determination by spectrofluorimetry.

    PubMed

    Tarigh, Ghazale Daneshvar; Shemirani, Farzaneh

    2014-06-01

    A simple and rapid method for the simultaneous in situ derivatizaion, preconcentration and extraction of thiamine (vitamin B1) as a model analyte was developed by a novel quantitative method, namely ultrasound-assisted dispersive magnetic solid phase extraction spectrofluorimetry (USA-DMSPE-FL) from different real samples. This method consists of sample preparation, in situ derivatization, exhaustive extraction and clean up by a single process. High extraction efficiency and in situ derivatization in a short period of time is the main advantages of this procedure. For this purpose, the reusable magnetic multi-wall carbon nanotube (MMWCNT) nanocomposite was used as an adsorbent for preconcentration and determination of thiamine. Thiamine was, simultaneously, in situ derivatized as thiochrome by potassium hexacyanoferrate (III) and adsorbed on MMWCNT in an ultrasonic water bath. The MMWCNTs were then collected using an external magnetic field. Subsequently, the extracted thiochrome was washed from the surface of the adsorbent and determined by spectrofluorimetry. The developed method, which has been analytically characterized under its optimal operating conditions, allows the detection of the analyte in the samples with method detection limits of 0.37 µg L(-1). The repeatability of the method, expressed as the relative standard deviation (RSD, n=6), varies between 2.0% and 4.8% in different real samples, while the enhancement factor is 197. The proposed procedure has been applied for the determination of thiamine in biological (serum and urine), pharmaceutical (multivitamin tablet and B complex syrup) and foodstuff samples (cereal, wheat flour, banana and honey) with the good recoveries in the range from 90% to 105%. PMID:24725866

  5. Restricted-access nanoparticles for magnetic solid-phase extraction of steroid hormones from environmental and biological samples.

    PubMed

    Ye, Lei; Wang, Qing; Xu, Jinping; Shi, Zhi-Guo; Xu, Li

    2012-06-29

    Restricted-access materials based on non-ionic surfactant-coated dodecyl-functionalized magnetic nanoparticles were prepared and applied to extract steroid hormones from environmental and biological samples. The magnetic nanoparticles were synthesized by co-precipitation, and were functionalized with dodecyltriethoxysilane, giving dodecyl-grafted magnetic nanoparticles (C₁₂-Fe₃O₄). They were further modified with different non-ionic surfactants by self-assembly adsorption. Several types of non-ionic surfactants, Tween-20, 40, 60 and 85, and Span-40, 60 and 80, were investigated as the coatings. Tween surfactants coated C₁₂-Fe₃O₄, named as TW-20 (40, 60, 85)-C₁₂, exhibited good dispersibility in aqueous solution, which was a preferred character in extraction; besides, TW-20-C₁₂ and TW-40-C₁₂ showed good anti-interference ability and satisfactory reproducibility when they were used as magnetic solid-phase extraction (MSPE) sorbents. The factors that may influence the extraction, including the amount of magnetic nanoparticles, extraction and desorption time, the amount of salt addition, the type and volume of desorption solvent, the volume of methanol addition and pH of sample solution, were investigated in detail. High performance liquid chromatography-UV detection was employed for analysis of target analytes (steroid hormone compounds). The developed method was successfully used for the determination of the target analytes in environmental and urine samples. Both tested materials afforded good recovery, satisfactory reproducibility and low limits of detection for environmental samples, which indicates that the materials possessed anti-interference ability. However, compared to TW-40-C₁₂, TW-20-C₁₂ nanoparticles provided better recovery in relatively complex biological samples, which may indicate that the latter one is more appreciated in complex samples. PMID:22621888

  6. Development and validation of a magnetic solid-phase extraction with high-performance liquid chromatography method for the simultaneous determination of amphetamine and methadone in urine.

    PubMed

    Taghvimi, Arezou; Hamishehkar, Hamed; Ebrahimi, Mahmoud

    2016-06-01

    The simultaneous determination of amphetamine and methadone was carried out by magnetic graphene oxide nanoparticles, a magnetic solid-phase extraction adsorbent, as a new sample treatment technique. The main factors (the amounts of sample volume, amount of adsorbent, type and amount of extraction organic solvent, time of extraction and desorption, pH, the ionic strength of extraction medium, and agitation rate) influencing the extraction efficiency were investigated and optimized. Under the optimized conditions, good linearity was observed in the range of 100-1500 ng/mL for amphetamine and 100-1000 ng/mL for methadone. The method was evaluated for determination of AM and methadone in positive urine samples, satisfactory results were obtained, therefore magnetic solid-phase extraction can be applied as a novel method for the determination of drugs of abuse in forensic laboratories. PMID:27091701

  7. Fabrication of a Dipole-assisted Solid Phase Extraction Microchip for Trace Metal Analysis in Water Samples.

    PubMed

    Shih, Tsung-Ting; Hsu, I-Hsiang; Chen, Ping-Hung; Chen, Shun-Niang; Tseng, Sheng-Hao; Deng, Ming-Jay; Lin, Yang-Wei; Sun, Yuh-Chang

    2016-01-01

    This paper describes a fabrication protocol for a dipole-assisted solid phase extraction (SPE) microchip available for trace metal analysis in water samples. A brief overview of the evolution of chip-based SPE techniques is provided. This is followed by an introduction to specific polymeric materials and their role in SPE. To develop an innovative dipole-assisted SPE technique, a chlorine (Cl)-containing SPE functionality was implanted into a poly(methyl methacrylate) (PMMA) microchip. Herein, diverse analytical techniques including contact angle analysis, Raman spectroscopic analysis, and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) analysis were employed to validate the utility of the implantation protocol of the C-Cl moieties on the PMMA. The analytical results of the X-ray absorption near-edge structure (XANES) analysis also demonstrated the feasibility of the Cl-containing PMMA used as an extraction medium by virtue of the dipole-ion interactions between the highly electronegative C-Cl moieties and the positively charged metal ions. PMID:27584954

  8. Determination of pyronaridine in whole blood by automated solid phase extraction and high-performance liquid chromatography.

    PubMed

    Blessborn, Daniel; Lindegårdh, Niklas; Ericsson, Orjan; Hellgren, Urban; Bergqvist, Yngve

    2003-06-01

    A new extraction procedure for the analysis of pyronaridine in whole blood is presented. A weak cation exchanger with a carboxylic acid (CBA) sorbent was found to be a suitable solid phase sorbent for the extraction of pyronaridine. High-performance liquid chromatography with UV detection at 278 nm and an electrochemical detector at +0.75 V is used. The electrochemical detector gives higher selectivity than the UV detector. The separation was performed using a C18 reversed phase column with mobile phase of acetonitrile-phosphate buffer (0.01 mol/L, pH 2.5)- sodium perchlorate (1.0 mol/L; 22:77:1, v/v/v). The within-day RSDs were below 5% at all concentration levels between 75 nmol/L and 1500 nmol/L, and the between-day RSDs were below 14% at all concentration levels. The limit of quantification was about 50 nmol/L in 1000 microL whole blood with an RSD of 20% or less on a day-to-day basis. The stability of pyronaridine is increased if the pH is less than 3 in water solutions. In whole blood, the concentration decreases by about 10% for each freeze-thaw cycle performed. At room temperature (about 22 degrees C), pyronaridine concentration in whole blood decreases by about 10% within 12 to 24 hours. PMID:12766551

  9. [Determination of dimethyl fumarate in leather and textiles by gas chromatography-tandem mass spectrometry with solid phase extraction].

    PubMed

    Zhao, Yang; Qi, Xiaoxia

    2010-01-01

    An effective method for the determination of dimethyl fumarate (DMF) in leather and textiles by gas chromatography-tandem mass spectrometry (GC-MS/MS) was developed. Samples of leather or textiles were extracted with ethyl acetate and concentrated, DMF was separated on a VF-5 ms column and analyzed by GC-MS/MS after solid phase extraction (SPE) process. The result shows that this method is sensitive, accurate and reliable. The linear relationship was perfect and the interference with background signal was further eliminated after pretreatment, SPE and GC-MS/MS analytical conditions were optimized. The average recoveries of DMF in leather and textiles at three levels ranged from 84% to 93%, the relative standard deviations (n = 6) were lower than 7.2%, the limits of detection in the range from 0.012 to 0.039 mg/kg (S/N = 3) , the correlation coefficient was 0.999 0 over the range 0.05 - 100 mg/L. It has been applied to routine determination of DMF in leather and textiles with satisfactory results. PMID:20458921

  10. Novel multiresidue method for determination of pesticides in red wine using gas chromatography-mass spectrometry and solid phase extraction.

    PubMed

    Pelajić, Maja; Peček, Gorana; Mutavdžić Pavlović, Dragana; Vitali Čepo, Dubravka

    2016-06-01

    A new multiresidue method was developed for determination of 25 pesticide residues in red wine by gas chromatography coupled to mass spectrometry with a single run of 23.63 min. Samples were extracted from wine with solid phase extraction using Oasis HLB. Mixture of methanol and water was used for rinsing, while acetonitrile and n-hexane were used as elution solvents. Method was validated according to SANCO/12571/2013 criteria in wide linearity range (limit of quantification - 400 μg L(-1)). Limits of quantification (LOQ) were well below 10 μg L(-1) for most pesticides and recoveries at 2×LOQ and 10×LOQ concentration levels were in range 70-120%. Precision, expressed as a relative standard deviation, was always under 14%. The method was applied to 32 red wine samples from Croatia. Pesticides were detected in 30 samples with a total of 15 pesticides found, 7 of which were at a high concentration. PMID:26830566

  11. Determination of catechins and catechin gallates in tissues by liquid chromatography with coulometric array detection and selective solid phase extraction.

    PubMed

    Chu, Kai On; Wang, Chi Chiu; Chu, Ching Yan; Rogers, Michael Scott; Choy, Kwong Wai; Pang, Chi Pui

    2004-10-25

    Catechins levels in organ tissues, particularly liver, determined by published methods are unexpectedly low, probably due to the release of oxidative enzymes, metal ions and reactive metabolites from tissue cells during homogenization and to the pro-oxidant effects of ascorbic acid during sample processing in the presence of metal ions. We describe a new method for simultaneous analysis of eight catechins in tissue: (+)-catechin (C), (-)-epicatechin (EC), (-)-gallocatechin (GC), (-)-epigallocatechin (EGC), (-)-catechin gallate (CG), (-)-epicatechin gallate (ECG), (-)-gallocatechin gallate (GCG) and (-)-epigallocatechin gallate (EGCG) (Fig. 1). The new extraction procedure utilized a methanol/ethylacetate/dithionite (2:1:3) mixture during homogenization for simultaneous enzyme precipitation and antioxidant protection. Selective solid phase extraction was used to remove most interfering bio-matrices. Reversed phase HPLC with CoulArray detection was used to determine the eight catechins simultaneously within 25 min. Good linearity (>0.9922) was obtained in the range 20-4000 ng/g. The coefficients of variance (CV) were less than 5%. Absolute recovery ranged from 62 to 96%, accuracy 92.5 +/- 4.5 to 104.9 +/- 6%. The detection limit was 5 ng/g. This method is capable for determining catechins in rat tissues of liver, brain, spleen, and kidney. The method is robust, reproducible, with high recovery, and has been validated for both in vitro and in vivo sample analysis. PMID:15380714

  12. Selective solid-phase extraction using oxidized activated carbon modified with triethylenetetramine for preconcentration of metal ions

    NASA Astrophysics Data System (ADS)

    Zhang, Li; Chang, Xijun; Li, Zhenhua; He, Qun

    2010-02-01

    A new selective solid-phase extractant using activated carbon as matrix which was purified, oxidized and modified by triethylenetetramine (AC-TETA) was prepared and characterized by FT-IR spectroscopy. At pH 4, quantitative extraction of trace Cr(III), Fe(III) and Pb(II) was obtained and determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Complete elution of the adsorbed metal ions from the sorbent surface was carried out using 0.5 mol L -1 HCl. The maximum static adsorption capacity of sorbent for Cr(III), Fe(III) and Pb(II) was 34.6, 36.5 and 51.9 mg g -1, respectively. The time of quantitative adsorption was less than 2 min. The detection limits of the method was found to be 0.71, 0.35 and 0.45 ng mL -1 for Cr(III), Fe(III) and Pb(II), and the relative standard deviation (RSD) was 3.7%, 2.2% and 2.5%, respectively. Moreover, the method was free from interference with common coexiting ions. The method was also successfully applied to the preconcentration of trace Cr(III), Fe(III) and Pb(II) in synthetic samples and a real sample with satisfactory results.

  13. Simultaneous Determination of Tetracyclines Residues in Bovine Milk Samples by Solid Phase Extraction and HPLC-FL Method

    PubMed Central

    Mesgari Abbasi, Mehran; Babaei, Hossein; Ansarin, Masoud; Nourdadgar, Ashraf-o-sadat; Nemati, Mahboob

    2011-01-01

    Introduction: Tetracyclines (TCs) are widely used in animal husbandry and their residues in milk may resultin harmful effects on human. The aim of this study was to investigate the presence of TCs residues in various bovine milk samples from local markets of Ardabil, Iran. Methods: One hundred and fourteen pasteurized, sterilized and raw milk samples were collected from markets of Ardabil. Tetracycline, Oxytetracycline and Chlortetracycline (TCs) residues extraction carried out by Solid Phase Extraction method. Determination of TCs residues were performed by high performance liquid chromatography (HPLC) method using Fluorescence detector. Results: The mean of total TCs residues in all samples (114 samples) was 97.6 ±16.9ng/g and that of pasteurized, sterilized and raw milk samples were 87.1 ± 17.7, 112.0 ± 57.3 and 154.0 ± 66.3ng/g respectively. Twenty five point four percent of the all samples, and 24.4%, 30% and 28.6% of the pasteurized, sterilized and raw milk samples, respectively had higher TCs residues than the recommended maximum levels (100ng/g). Conclusion: This study indicates the presence of tetracycline residues more than allowed amount. Regulatory authorities should ensure proper withdrawal period before milking the animals and definite supervisions are necessary on application of these drugs. PMID:24312754

  14. Solid-Phase Extraction and Simultaneous Determination of Tetracycline Residues in Edible Cattle Tissues Using an HPLC-FL Method

    PubMed Central

    Mesgari Abbasi, Mehran; Nemati, Mahboob; Babaei, Hossein; Ansarin, Masoud; Nourdadgar, Ashraf-O-Sadat

    2012-01-01

    In this assay, edible cattle tissues from local markets of Ardabil, a Province of Iran, were examined for residues of tetracycline antibiotics (tetracycline, oxytetracycline and chlortetracycline). In total, 110 samples of triceps, gluteal muscle, diaphragm, kidney and liver were randomly obtained from the local markets of the city of Ardabil. Solid-phase extraction (SPE) and high-performance liquid chromatography (HPLC) methods were used to extract and analyze tetracycline antibiotic (TC) residues, respectively. The mean amount of total TC residues in all tested samples was 226.3 ± 112.5 ng/g and the mean amount of the total TC residues in triceps, gluteal muscle, diaphragm, kidney and liver samples were 176.3 ± 46.8, 405.3 ± 219.6, 96.8 ± 26.9, 672.4 ± 192.0 and 651.3 ± 210.1 ng/g, respectively. Additionally, 25.8% of muscle samples, 31.8% of liver samples and 22.7% of kidney samples contained amounts of TC residues beyond the maximum residue limit (MRLs). To reduce the TC residues found in edible cattle tissues, regulatory authorities should ensure that the cattle would undergo the proper withdrawal period from TCs before the slaughtering. PMID:24250505

  15. Graphene oxide-based microspheres for the dispersive solid-phase extraction of non-steroidal estrogens from water samples.

    PubMed

    Wen, Yingying; Niu, Zongliang; Ma, Yanling; Ma, Jiping; Chen, Lingxin

    2014-11-14

    A modified Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method based on the dispersive solid-phase extraction (dSPE) combined with high performance liquid chromatography (HPLC) was developed for the determination of non-steroidal estrogens in water samples. In this study, graphene oxide-based silica microspheres (SiO2@GO) were used as dSPE material for the preconcentration of analytes. HPLC was used for the separation and detection. This was the first time that the synthesized SiO2@GO microspheres were used as stationary phases for the off-line preconcentration of the non-steroidal estrogens in dSPE. dSPE parameters, such as sample pH, volume and type of eluent were optimized. Application of the developed method to analyze spiked lake, reservoir and tap water samples resulted in good recoveries values ranging from 70 to 106% with relative standard deviation values lower than 7.0% in all cases. Limits of detection were in the range of 0.2-6.1 μg/L. The combined data obtained in this study recommended that the proposed method is very fast, simple, repeatable and accurate for the detection of non-steroidal estrogens. Furthermore, the SiO2@GO microspheres application could potentially be expanded to extract and pre-concentrate other compounds in various matrices. PMID:25441340

  16. A solid phase extraction-ion chromatography with conductivity detection procedure for determining cationic surfactants in surface water samples.

    PubMed

    Olkowska, Ewa; Polkowska, Żaneta; Namieśnik, Jacek

    2013-11-15

    A new analytical procedure for the simultaneous determination of individual cationic surfactants (alkyl benzyl dimethyl ammonium chlorides) in surface water samples has been developed. We describe this methodology for the first time: it involves the application of solid phase extraction (SPE-for sample preparation) coupled with ion chromatography-conductivity detection (IC-CD-for the final determination). Mean recoveries of analytes between 79% and 93%, and overall method quantification limits in the range from 0.0018 to 0.038 μg/mL for surface water and CRM samples were achieved. The methodology was applied to the determination of individual alkyl benzyl quaternary ammonium compounds in environmental samples (reservoir water) and enables their presence in such types of waters to be confirmed. In addition, it is a simpler, less time-consuming, labour-intensive, avoiding use of toxic chloroform and significantly less expensive methodology than previously described approaches (liquid-liquid extraction coupled with liquid chromatography-mass spectrometry). PMID:24148395

  17. 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. PMID:24128462

  18. Application of microwave-assisted micro-solid-phase extraction for determination of parabens in human ovarian cancer tissues.

    PubMed

    Sajid, Muhammad; Basheer, Chanbasha; Narasimhan, Kothandaraman; Choolani, Mahesh; Lee, Hian Kee

    2015-09-01

    Parabens (alkyl esters of p-hydroxybenzoic acid) are widely used as preservatives in food, cosmetics and pharmaceutical products. However, weak estrogenicity of some parabens has been reported in several studies, which provided the impetus for this work. Here, a simple and efficient analytical method for quantifying parabens in cancer tissues has been developed. This technique involves the simultaneous use of microwave-assisted solvent extraction (MASE) and micro-solid phase extraction (μ-SPE), in tandem with high performance liquid chromatography (HPLC/UV) analysis for the determination of parabens. The pollutants studied included four parabens (methyl, ethyl, propyl and butyl parabens). Optimization of the experimental parameters for MASE and μ-SPE was performed. Good relative standard deviation (%RSD) ranged from 0.09 to 2.81% and high enrichment factors (27-314) were obtained. Coefficients of determination (r(2)) up to 0.9962 were obtained across a concentration range of 5.0-200ngg(-1). The method detection limits for parabens ranged from 0.005 to 0.0244ngg(-1). The procedure was initially tested on prawn samples to demonstrate its feasibility on a complex biological matrix. Preliminary studies on human ovarian cancer (OC) tissues showed presence of parabens. Higher levels of parabens were detected in malignant ovarian tumor tissues compared to benign tumor tissue samples. PMID:26245364

  19. Profiling of soluble neutral oligosaccharides from treated biomass using solid phase extraction and LC-TOF MS.

    PubMed

    Vismeh, Ramin; Humpula, James F; Chundawat, Shishir P S; Balan, Venkatesh; Dale, Bruce E; Jones, A Daniel

    2013-05-15

    Thermochemical pretreatments of cellulosic biomass are known to improve cell wall enzymatic digestibility, while simultaneously releasing substantial amounts of soluble oligosaccharides. Profiling of oligosaccharides released during pretreatment yields information essential for choosing glycosyl hydrolases necessary for cost-effective conversion of cellulosic biomass to desired biofuel/biochemical end-products. In this report we present a methodology for profiling of soluble neutral oligosaccharides released from ammonia fiber expansion (AFEX™)-pretreated corn stover. Our methodology employs solid phase extraction (SPE) enrichment of oligosaccharides using porous graphitized carbon (PGC), followed by high performance liquid chromatography (HPLC) separation using a polymeric amine based column and electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS). For structural elucidation on the chromatographic time scale, nonselective multiplexed collision-induced dissociation was performed for quasi-simultaneous acquisition of oligosaccharide molecular and fragment masses in a single analysis. These analyses revealed glucans up to degree of polymerization (DP) 22 without modifications. Additionally, arabinoxylans up to DP=6 were detected in pretreated biomass extracts (post-enzymatic digestion). Cross-ring fragment ion abundances were consistent with assignment of linkages between sugar units in glucans and also xylose backbone in arabinoxylans as 1-4 linkages. Comprehensive profiling of soluble oligosaccharides also demonstrated decreases in levels of acetate esters of arabinoxylan oligosaccharides with concomitant increases in nonacetylated oligosaccharides that were consistent with earlier observations of 85% release of acetate esters by AFEX™ pretreatment. PMID:23544634

  20. Development and characterization of a new polyampholyte-surfactant complex applied to the solid phase extraction of bisphenol-A.

    PubMed

    Martínez, J M Lázaro; Denis, M F Leal; Denaday, L R; Dall' Orto, V Campo

    2009-12-15

    This paper presents a material that has both hydrophilic and hydrophobic domains, obtained by combination of a polyampholyte with a surfactant. This material was fully characterized by different spectroscopic techniques and microscopy. Bisphenol-A (BPA) was chosen as a model molecule to study the interaction with compounds of intermediate polarity. We explored the kinetics and equilibrium of BPA on the surface of the polyampholyte-surfactant complex and found a significantly high loading capacity (2.02 mmol g(-1)) and complete binding from solutions at concentration levels below 100 micromol L(-1). The complex was encapsulated in agarose gel to be used as solid phase for extraction of BPA from food simulants in contact with polycarbonate bottles under different treatments. Bisphenol was preconcentrated, extracted and analysed by liquid chromatography with an amperometric detector. The instrumental detection limit of the technique was 10 microg L(-1), which was lowered to 0.14 microg L(-1) by the preconcentration step. The BPA released from baby bottles was 2.1 ng cm(-2) (sigma(n-1): 0.1) in the first use with distilled water. PMID:19836553

  1. Zwitterionic hydrophilic interaction solid-phase extraction and multi-dimensional mass spectrometry for shotgun lipidomic study of Hypophthalmichthys nobilis.

    PubMed

    Jin, Renyao; Li, Linqiu; Feng, Junli; Dai, Zhiyuan; Huang, Yao-Wen; Shen, Qing

    2017-02-01

    Zwitterionic hydrophilic interaction liquid chromatography (ZIC-HILIC) material was used as solid-phase extraction sorbent for purification of phospholipids from Hypophthalmichthys nobilis. The conditions were optimized to be pH 6, flow rate 2.0mL·min(-1), loading breakthrough volume ⩽5mL, and eluting solvent 5mL. Afterwards, the extracts were analyzed by multi-dimensional mass spectrometry (MDMS) based shotgun lipidomics; 20 species of phosphatidylcholine (PC), 22 species of phosphatidylethanoamine (PE), 15 species of phosphatidylserine (PS), and 5 species of phosphatidylinositol (PI) were identified, with content 224.1, 124.1, 27.4, and 34.7μg·g(-1), respectively. The MDMS method was validated in terms of linearity (0.9963-0.9988), LOD (3.7ng·mL(-1)), LOQ (9.8ng·mL(-1)), intra-day precision (<3.64%), inter-day precision (<5.31%), and recovery (78.8-85.6%). ZIC-HILIC and MDMS shotgun lipidomics are efficient for studying phospholipids in H. nobilis. PMID:27596430

  2. Screening of volatile composition of Lavandula hybrida Reverchon II honey using headspace solid-phase microextraction and ultrasonic solvent extraction.

    PubMed

    Jerković, Igor; Marijanović, Zvonimir

    2009-03-01

    The volatiles of unifloral Lavandula hybrida Reverchon II honey were isolated by means of headspace solid-phase microextraction (HS-SPME) and ultrasonic solvent extraction (USE) and analyzed by gas chromatography and mass spectrometry (GC, GC/MS). A total of 23 compounds were identified in the headspace with hexan-1-ol, hexanal, acetic acid, hotrienol, and 2-phenylacetaldehyde as the principal components. Three solvents of different polarity were used for USE, and a total of 53 compounds were identified. The extracts with pentane/Et(2)O 1 : 2 (v/v) were the most representative for USE method containing the majority of the honey floral origin compounds and potential biomarkers (hexanol, acetic acid, butane-1,3-diol, butane-2,3-diol, benzoic acid, coumarin, and 2-phenylacetic acid). The total number of identified compounds (USE and HS-SPME) was 59. In general, the comparison with volatiles of other lavandin honeys of different geographic origins indicated several similarities, while acetic and formic acids were identified with high percentages in L. hybrida Reverchon II honey. PMID:19319870

  3. Graphene based pipette tip solid phase extraction of marine toxins in shellfish muscle followed by UPLC-MS/MS analysis.

    PubMed

    Shen, Qing; Gong, Like; Baibado, Joewel T; Dong, Wei; Wang, Yixuan; Dai, Zhiyuan; Cheung, Hon-Yeung

    2013-11-15

    Graphene is a novel carbonic material with great potentials for the use as sorbent due to its ultrahigh surface area. Herein, we report the use of graphene as sorbent in solid-phase extraction (SPE) using pipette tip as cartridge namely GPT-SPE, together with ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS), for the analysis of lipophilic marine toxins (LMTs), including yessotoxins (YTX), okadaic acid (OA), dinophysistoxin-1 (DTX1), gymnodimine (GYM), spirolides-1 (SPX1), pectenotoxin-2 (PTX2) and azaspiracid-1 (AZA1) in shellfish. The GPT-SPE procedure was optimized and the performance of graphene was fully validated. Results with high-sensitivity and good reproducibility was obtained and compared with that of other sorbents like C18 silica, multi-walled carbon nanotubes (MWCNTs), commercial Oasis HLB, and Strata-X for the extraction of LMTs, which showed superiority and advantages of graphene, such as good recoveries, stability and compatibility with various solvents. In order to exhibit the potentials of graphene as an excellent sorbent material, 67 mussel samples from six coastal cities of China were analyzed. OA was found to be the dominant contaminant, while YTX was also detected with low level. PMID:24148472

  4. Determination of tetracyclines residues in honey by on-line solid-phase extraction high-performance liquid chromatography.

    PubMed

    Li, Jiantao; Chen, Ligang; Wang, Xiao; Jin, Haiyan; Ding, Lan; Zhang, Kun; Zhang, Hanqi

    2008-06-15

    An automated system using on-line solid-phase extraction (SPE) high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection was developed for the determination of tetracyclines (TCs), such as tetracycline (TC), oxytetracycline (OTC), chlortetracycline (CTC), metacycline (MC), and doxycycline (DC) in honey. One milliliter diluted honey sample was injected into a conditioned C18 SPE column and the matrix was washed out with water for 3 min. By rotation of the switching valve, TCs were eluted and transferred to the analytical column by the chromatographic mobile phase. Chromatographic conditions were optimized. TCs were separated in less than 8 min with a gradient elution using a mixture of 0.8% formic acid and acetonitrile. The UV detection was performed at 365 nm. The conditions for on-line SPE, including solvent and total time for loading sample and washing matrix were also optimized. Time for extraction and separation decreased greatly. For the five kinds of TCs, the limits of detection (LODs) at a signal-to-noise of 3 ranged from 5 to 12 ng g(-1). The relative standard deviations (R.S.D.) for the determination of TCs ranged from 3.4 to 7.1% within a day and ranged from 3.2 to 8.9% in 3 days, respectively. PMID:18585209

  5. A high performance system to study the influence of temperature in on-line solid-phase extraction capillary electrophoresis.

    PubMed

    Tascon, Marcos; Benavente, Fernando; Sanz-Nebot, Victoria; Gagliardi, Leonardo G

    2015-03-10

    A novel high performance system to control the temperature of the microcartridge in on-line solid phase extraction capillary electrophoresis (SPE-CE) is introduced. The mini-device consists in a thermostatic bath that fits inside of the cassette of any commercial CE instrument, while its temperature is controlled from an external circuit of liquid connecting three different water baths. The circuits are controlled from a switchboard connected to an array of electrovalves that allow to rapidly alternate the water circulation through the mini-thermostatic-bath between temperatures from 5 to 90 °C. The combination of the mini-device and the forced-air thermostatization system of the commercial CE instrument allows to optimize independently the temperature of the sample loading, the clean-up, the analyte elution and the electrophoretic separation steps. The system is used to study the effect of temperature on the C18-SPE-CE analysis of the opioid peptides, Dynorphin A (Dyn A), Endomorphin1 (END) and Met-enkephalin (MET), in both standard solutions and in spiked plasma samples. Extraction recoveries demonstrated to depend, with a non-monotonous trend, on the microcartridge temperature during the sample loading and became maximum at 60 °C. Results prove the potential of temperature control to further enhance sensitivity in SPE-CE when analytes are thermally stable. PMID:25732315

  6. Solid-phase extraction of explosive nitramines on macroreticular polymers modified by freezing with water or acetone.

    PubMed

    Tomaszewski, Waldemar; Gun'ko, Vladimir M; Skubiszewska-Zięba, Jadwiga

    2016-04-01

    A novel approach is proposed to modify the porous structure and surface properties of the polymers used in solid-phase extraction. The approach involves soaking in water or acetone, followed by freezing in liquid nitrogen (77.4 K) and was employed for two polymeric materials: Amberlite XAD-7 and Amberlite XAD-16. Variations in the surface properties of the adsorbents were justified by the action of acetone and water as solvents affecting the textural and other characteristic of the materials. The initial and treated adsorbents were used in extraction of explosive nitramines from aqueous samples. The performed modifications of the polymer texture allow us to increase the recovery rate as compared with the initial adsorbents. The results were justified by the swelling of fragments of the polymers and by the additional process of sorption of nitramines. The results indicate that polymeric adsorbents can be easily modified by the soaking/freezing process and the materials can be achieved that prove usefulness for the effective separation of explosive nitramines from aqueous samples. PMID:26899536

  7. Determination of triazine herbicides in fruits and vegetables using dispersive solid-phase extraction coupled with LC-MS.

    PubMed

    Ji, Feng; Zhao, Lixia; Yan, Wei; Feng, Qinzhong; Lin, Jin-Ming

    2008-04-01

    A simple, rapid, and sensitive liquid chromatography-mass spectrometry (LC-MS) method was successfully developed for the determination of three chloro-s-triazine herbicides, viz. atrazine, simazine, and propazine, two thiomethyl-s-triazine ones, viz. ametryn and prometryn, and prometon in fruits and vegetables. The instrumental parameters affecting LC separation and MS detection were investigated and the best conditions were selected. Samples were extracted and purified by dispersive solid-phase extraction (dispersive-SPE) with a primary-secondary amine sorbent. Three typical representative samples (luffa, broad bean, and grape) were selected to investigate the effect of different matrices on pesticide recoveries and assay precision after spiking at 0.05 mg/kg. Matrix composition did not interfere significantly with the determination of these pesticides. The recoveries were, with a few exceptions, in the range of 80-110% with relative standard deviations less than 10% (n = 5). In addition, this method was also applied to 21 different kinds of agriculture products collected from the local market, and two of the six triazines could be detected and quantified. PMID:18338404

  8. Use of solid phase extraction for the sequential injection determination of alkaline phosphatase activity in dynamic water systems.

    PubMed

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

    2012-08-30

    In this work, a solid phase extraction sequential injection methodology for the determination of alkaline phosphatase activity in dynamic water systems was developed. The determination of the enzymatic activity was based on the spectrophotometric detection of a coloured product, p-nitrophenol, at 405 nm. The p-nitrophenol is the product of the catalytic decomposition of p-nitrophenyl phosphate, a non-coloured substrate. Considering the low levels expected in natural waters and exploiting the fact of alkaline phosphatase being a metalloprotein, the enzyme was pre-concentrated in-line using a NTA Superflow resin charged with Zn(2+) ions. The developed sequential injection method enabled a quantification range of 0.044-0.441 unit mL(-1) of enzyme activity with a detection limit of 0.0082 unit mL(-1) enzyme activity (1.9 μmol L(-1) of pNP) and a determination rate of 17 h(-1). Recovery tests confirmed the accuracy of the developed sequential injection method and it was effectively applied to different natural waters and to plant root extracts. PMID:22939148

  9. Determination of Low Levels of Lead in Beer Using Solid-Phase Extraction and Detection by Flame Atomic Absorption Spectrometry

    PubMed Central

    Alves, Vanessa N.; Borges, Simone S. O.; Neto, Waldomiro B.; Coelho, Nívia M. M.

    2011-01-01

    In this study, a method for the determination of low concentrations of lead in beer samples using solid-phase extraction with a flow injection analysis system and detection by flame atomic absorption spectrometry (FAAS) was developed. Moringa oleifera seeds were used as a biosorbent material. Chemical and flow variables of the online preconcentration system, such as sample pH, preconcentration flow rate, eluent flow rate, eluent concentration, particle size, and sorbent mass, were studied. The optimum extraction conditions were obtained using a sample pH of 6.0, sample flow rate of 6.0 mL min−1, 63.0 mg of sorbent mass, and 2.0 mol L−1 HNO3 at a flow rate of 2.0 mL min−1 as the eluent. With the optimized conditions, the preconcentration factor, precision, detection limit, consumption index, and sample throughput were estimated as 93, 0.3% (10.0 μg L−1, n = 7), 7.5 μg L−1, 0.11 mL, and 23 samples per hour, respectively. The method developed was successfully applied to beer samples and recovery tests, with recovery ranging from 80% to 100%. PMID:22013389

  10. Direct detection of Mycobacterium tuberculosis in sputum using combined solid phase extraction-gas chromatography-mass spectrometry.

    PubMed

    Dang, Ngoc A; Mourão, Marta; Kuijper, Sjoukje; Walters, Elisabetta; Janssen, Hans-Gerd; Kolk, Arend H J

    2015-04-01

    Recently, thermally-assisted hydrolysis and methylation followed by gas chromatography-mass spectrometry (THM-GC-MS) in combination with chemometrics has been used to develop a 20-compound model for fast differentiation of Mycobacterium tuberculosis (MTB) from Non-tuberculous mycobacteria (NTM) in bacterial cultures. This model provided better than 95% accuracy. In our current work a hexane/methanol/water extraction followed by a solid phase extraction (SPE) clean-up procedure was developed for use before THM-GC-MS, to make the test suitable for the identification of mycobacteria in sputum. The 20 biomarker model had to be adapted since many compounds were also found in the sputum of non-tuberculosis patients. An algorithm was established based on tuberculostearic acid, hexacosanoic acid and mycoserosates. The detection limit of the method was approximately 1×10(4) bacteria/mL sputum. Sputum specimens from 32 patients from South Africa who were suspected of having tuberculosis were blindly tested using the new method. Eight of the nine culture-positive sputum specimens were detected by the new SPE-THM-GC-MS method, resulting in a sensitivity of 89%. The specimen that was missed by the new method was also microscopy negative. The specificity of the test was 100%; all 23 microscopy- and culture-negative specimens were correctly identified as negative by SPE-THM-GC-MS. PMID:25728368

  11. Determination of the Antibiotic Oxytetracycline in Commercial Milk by Solid-Phase Extraction: A High-Performance Liquid Chromatography (HPLC) Experiment for Quantitative Instrumental Analysis

    ERIC Educational Resources Information Center

    Mei-Ratliff, Yuan

    2012-01-01

    Trace levels of oxytetracylcine spiked into commercial milk samples are extracted, cleaned up, and preconcentrated using a C[subscript 18] solid-phase extraction column. The extract is then analyzed by a high-performance liquid chromatography (HPLC) instrument equipped with a UV detector and a C[subscript 18] column (150 mm x 4.6 mm x 3.5 [mu]m).…

  12. Mixed-mode isolation of triazine metabolites from soil and aquifer sediments using automated solid-phase extraction

    USGS Publications Warehouse

    Mills, M.S.; Thurman, E.M.

    1992-01-01

    Reversed-phase isolation and ion-exchange purification were combined in the automated solid-phase extraction of two polar s-triazine metabolites, 2-amino-4-chloro-6-(isopropylamino)-s-triazine (deethylatrazine) and 2-amino-4-chloro-6-(ethylamino)-s-triazine (deisopropylatrazine) from clay-loam and slit-loam soils and sandy aquifer sediments. First, methanol/ water (4/1, v/v) soil extracts were transferred to an automated workstation following evaporation of the methanol phase for the rapid reversed-phase isolation of the metabolites on an octadecylresin (C18). The retention of the triazine metabolites on C18 decreased substantially when trace methanol concentrations (1%) remained. Furthermore, the retention on C18 increased with decreasing aqueous solubility and increasing alkyl-chain length of the metabolites and parent herbicides, indicating a reversed-phase interaction. The analytes were eluted with ethyl acetate, which left much of the soil organic-matter impurities on the resin. Second, the small-volume organic eluate was purified on an anion-exchange resin (0.5 mL/min) to extract the remaining soil pigments that could foul the ion source of the GC/MS system. Recoveries of the analytes were 75%, using deuterated atrazine as a surrogate, and were comparable to recoveries by soxhlet extraction. The detection limit was 0.1 ??g/kg with a coefficient of variation of 15%. The ease and efficiency of this automated method makes it viable, practical technique for studying triazine metabolites in the environment.

  13. Preparation of magnetite-loaded silica microspheres for solid-phase extraction of genomic DNA from soy-based foodstuffs.

    PubMed

    Shi, Ruobing; Wang, Yucong; Hu, Yunli; Chen, Lei; Wan, Qian-Hong

    2009-09-01

    Solid-phase extraction has been widely employed for the preparation of DNA templates for polymerase chain reaction (PCR)-based analytical methods. Among the variety of adsorbents studied, magnetically responsive silica particles are particularly attractive due to their potential to simplify, expedite, and automate the extraction process. Here we report a facile method for the preparation of such magnetic particles, which entails impregnation of porous silica microspheres with iron salts, followed by calcination and reduction treatments. The samples were characterized using powder X-ray diffractometry (XRD), scanning electron microscopy (SEM), nitrogen adsorption/desorption isotherms, and vibrating sample magnetometry (VSM). XRD data show that magnetite nanocrystals of about 27.2 nm are produced within the pore channels of the silica support after reduction. SEM images show that the as-synthesized particles exhibit spherical shape and uniform particle size of about 3 microm as determined by the silica support. Nitrogen sorption data confirm that the magnetite-loaded silica particles possess typical mesopore structure with BET surface area of about 183 m(2)/g. VSM data show that the particles display paramagnetic behavior with saturation magnetization of 11.37 emu/g. The magnetic silica microspheres coated with silica shells were tested as adsorbents for rapid extraction of genomic DNA from soybean-derived products. The purified DNA templates were amplified by PCR for screening of genetically modified organisms (GMOs). The preliminary results confirm that the DNA extraction protocols using magnetite-loaded silica microspheres are capable of producing DNA templates which are inhibitor-free and ready for downstream analysis. PMID:19632684

  14. Sol-gel-based silver nanoparticles-doped silica – Polydiphenylamine nanocomposite for micro-solid-phase extraction.

    PubMed

    Bagheri, Habib; Banihashemi, Solmaz

    2015-07-30

    A nanocomposite of silica-polydiphenylamine doped with silver nanoparticles (Ag-SiO2-PDPA) was successfully synthesized by the sol-gel process. For its preparation, PDPA was mixed with butanethiol capped Ag nanoparticles (NPs) and added to the silica sol solution. The Ag NPs were stabilized as a result of their adsorption on the SiO2 spheres. The surface characteristic of nanocomposite was investigated using scanning electron microscopy (SEM). In this work the Ag-SiO2-PDPA nanocomposite was employed as an efficient sorbent for micro-solid-phase extraction (μ-SPE) of some selected pesticides. An amount of 15 mg of the prepared sorbent was used to extract and determine the representatives from organophosphorous, organochlorine and aryloxyphenoxy propionic acids from aqueous samples. After the implementation of extraction process, the analytes were desorbed by methanol and determined using gas chromatography-mass spectrometry (GC-MS). Important parameters influencing the extraction and desorption processes such as pH of sample solution, salting out effect, type and volume of the desorption solvent, the sample loading and eluting flow rates along with the sample volume were experimentally optimized. Limits of detection (LODs) and the limits of quantification (LOQs) were in the range of 0.02-0.05 μg L(-1) and 0.1-0.2 μg L(-1), respectively, using time scheduled selected ion monitoring (SIM) mode. The relative standard deviation percent (RSD %) with four replicates was in the range of 6-10%. The applicability of the developed method was examined by analyzing different environmental water samples and the relative recovery (RR %) values for the spiked water samples were found to be in the range of 86-103%. PMID:26320636

  15. Developments in coupled solid-phase extraction-capillary electrophoresis 2011-2013.

    PubMed

    Ramautar, Rawi; Somsen, Govert W; de Jong, Gerhardus J

    2014-01-01

    This article presents an overview of the design and application of coupled SPE-CE systems that have been reported in the literature between January 2011 and June 2013. The present paper is an update of three previous review papers covering the years 2000-2011 (Electrophoresis 2008, 29, 108-128; Electrophoresis 2010, 31, 44-54; Electrophoresis 2012, 33, 243-250). The use of in-line and on-line SPE-CE approaches is described in this review. Emerging technological developments, such as the use of in-line frit-free SPE and chip-based SPE for extraction of sample components prior to CE analysis, are outlined. Selected examples illustrate the applicability of SPE-CE in biomedical, pharmaceutical, and environmental analysis. A complete overview of recent SPE-CE studies is given in table format, providing information on sample type, SPE sorbent, coupling mode, detection mode, and LOD. Finally, some general conclusions and future perspectives are provided. PMID:24114847

  16. Utilizing thin-film solid-phase extraction to assess the effect of organic carbon amendments on the bioavailability of DDT and dieldrin to earthworms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Improved approaches are needed to rapidly and accurately assess the bioavailability of persistent, hydrophobic organic compounds in soils at contaminated sites. The performance of a thin-film solid-phase extraction (TF-SPE) assay using vials coated with ethylene vinyl acetate polymer was compared to...

  17. Analysis of trifluralin, methyl paraoxon, methyl parathion, fenvalerate and 2,4-D dimethylamine in pond water using solid-phase extraction

    USGS Publications Warehouse

    Swineford, D.M.; Belisle, A.A.

    1989-01-01

    A method was developed for the simultaneous extraction of trifluralin, methyl paraoxon, methyl parathion, fenvalerate, and 2,4-D dimethylamine salt in pond water using a solid-phase C18 column. After elution from the C18 column, the eluate was analyzed on a capillary gas chromatograph equipped with an electron-capture or flame photometric detector.

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

    EPA Science Inventory

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

  19. METHOD 544. DETERMINATION OF MICROCYSTINS AND NODULARIN IN DRINKING WATER BY SOLID PHASE EXTRACTION AND LIQUID CHROMATOGRAPHY/TANDEM MASS SPECTROMETRY (LC/MS/MS)

    EPA Science Inventory

    Method 544 is an accurate and precise analytical method to determine six microcystins (including MC-LR) and nodularin in drinking water using solid phase extraction and liquid chromatography tandem mass spectrometry (SPE-LC/MS/MS). The advantage of this SPE-LC/MS/MS is its sensi...

  20. DEVELOPMENT OF METHOD 535 FOR THE DETERMINATION OF CHLOROACETANILIDE AND OTHER ACETAMIDE HERBICIDE DEGRADATES IN DRINKING WATER BY SOLID PHASE EXTRACTION AND LIQUID CHROMATOGRAPHY/TANDEM MASS SPECTROMETRY

    EPA Science Inventory

    EPA Method 535 has been developed in order to provide a method for the analysis of "Alachlor ESA and other acetanilide degradation products" which are listed on U.S. EPA's 1998 Drinking Water Contaminant Candidate List. Method 535 uses solid phase extraction with a nonporous gr...

  1. Graphene-encapsulated silica as matrix solid-phase dispersion extraction sorbents for the analysis of poly-methoxylated flavonoids in the leaves of Murraya panaculata (L.) Jack.

    PubMed

    Sun, Ting; Li, Xuwen; Yang, Jie; Li, Lanjie; Jin, Yongri; Shi, Xiaolei

    2015-06-01

    In this study, graphene-encapsulated silica was synthesized by a hydrothermal reduction strategy. The presence of silica in graphene was identified by Fourier-transform infrared spectrometry, X-ray diffraction and scanning electron microscopy. The graphene-encapsulated silica subsequently was used as adsorbent for matrix solid-phase dispersion extraction of poly-methoxylated flavonoids from the dried leaves of Murraya panaculata (L.) Jack. Compared with the other adsorbents (graphene, silica gel, C18 silica, neutral alumina, diatomaceous earth) and without any adsorbents, better results were obtained. Then a method for analysis of poly-methoxylated flavonoids was established by coupling matrix solid-phase dispersion extraction with ultra high performance liquid chromatography and UV detection. Compared with reflux extraction and ultrasonic extraction, the proposed method is quicker, more efficient and more environmental protection. Less than 10 min is needed from extraction to detection. PMID:25847864

  2. Improvement of extraction capability of magnetic molecularly imprinted polymer beads in aqueous media via dual-phase solvent system.

    PubMed

    Hu, Yuling; Liu, Ruijin; Zhang, Yi; Li, Gongke

    2009-08-15

    In this study, a novel and simple dual-phase solvent system for the improvement of extraction capability of magnetic molecularly imprinted polymer (MIP) beads in aqueous sample was proposed. The method integrated MIP extraction and micro-liquid-liquid extraction (micro-LLE) into only one step. A magnetic MIP beads using atrazine as template was synthesized, and was applied to aqueous media by adding micro-volume of n-hexane to form a co-extraction system. The magnetic MIP beads preferred to suspend in the organic phase, which shielded them from the disturbance of water molecule. The target analytes in the water sample was extracted into the organic phase by micro-LLE and then further bound to the solid-phase of magnetic MIP beads. The beads specificity was significantly improved with the imprinting efficiency of template increasing from 0.5 to 4.4, as compared with that in pure aqueous media. The extraction capacity, equilibration process and cross-selectivity of the MIP dual-phase solvent extraction system were investigated. The proposed method coupled with high-performance liquid chromatography was applied to the analysis of atrazine, simazine, propazine, simetryn, prometryne, ametryn and terbutryn in complicated sample such as tomato, strawberry juice and milk. The method is selective, sensitive and low organic solvent-consuming, and has potential to broaden the range of MIP application in biological and environmental sample. PMID:19576415

  3. Application of dissolvable layered double hydroxides as sorbent in dispersive solid-phase extraction and extraction by co-precipitation for the determination of aromatic acid anions.

    PubMed

    Tang, Sheng; Lee, Hian Kee

    2013-08-01

    Three types of magnesium-aluminum layered double hydroxides were synthesized and employed as solid-phase extraction (SPE) sorbents to extract several aromatic acids (protocatechuic acid, mandelic acid, phthalic acid, benzoic acid, and salicylic acid) from aqueous samples. An interesting feature of these sorbents is that they dissolve when the pH of the solution is lower than 4. Thus, the analyte elution step, as needed in conventional sorbent-based extraction, was obviated by dissolving the sorbent in acid after extraction and separation from the sample solution. The extract was then directly injected into a high-performance liquid chromatography-ultraviolet detection system for analysis. In the key adsorption process, both dispersive SPE and co-precipitation extraction with the sorbents were conducted and experimental parameters such as pH, temperature, and extraction time were optimized. The results showed that both extraction methods provided low limits of detection (0.03-1.47 μg/L) and good linearity (r(2) > 0.9903). The optimized extraction conditions were applied to human urine and sports drink samples. This new and interesting extraction approach was demonstrated to be a fast and efficient procedure for the extraction of organic anions from aqueous samples. PMID:23855757

  4. Rapid preparation of molecularly imprinted polymers by microwave-assisted emulsion polymerization for the extraction of florfenicol in milk.

    PubMed

    Chen, Haiyan; Son, Sunil; Zhang, Fengshuang; Yan, Jin; Li, Yi; Ding, Hong; Ding, Lan

    2015-03-01

    In this study, we proposed a rapid and simple method for the preparation of molecularly imprinted polymers (MIPs) by emulsion polymerization. The polymerization process was accelerated by microwave heating, and the reaction time was greatly shortened. The obtained MIPs were spherical in shape and exhibited a uniform morphology. The MIPs with selectivity and high affinity to florfenicol were successfully applied as solid-phase extraction materials to extract and clean up the florfenicol in milk, followed by liquid chromatography-tandem mass spectrometry (LC-MS) analysis. The parameters affecting the performance of extraction and LC-MS analysis were evaluated. The detection limit of the method was 4.1ngmL(-1). The relative standard deviations of intra- and inter-day were in the range of 3.5-4.7% and 3.9-7.5%, respectively. PMID:25614968

  5. Progress of solid-phase microextraction coatings and coating techniques.

    PubMed

    Jiang, Guibin; Huang, Minjia; Cai, Yaqi; Lv, Jianxia; Zhao, Zongshan

    2006-07-01

    Solid-phase microextraction (SPME) has been popular as an environmentally friendly sample pretreatment technique to extract a very wide range of analytes. This is partly owing to the development of SPME coatings. One of the key factors affecting the extraction performances, such as the sensitivity, selectivity, and reproducibility, is the properties of the coatings on SPME fibers. This paper classifies the materials used as SPME coatings and introduces some common preparation techniques of SPME coating in detail, such as sol-gel technique, electrochemical polymerization technique, particle direct pasting technique, restricted access matrix SPME technique, and molecularly imprinted SPME technique. PMID:16884587

  6. Pesticide determination in rose petals using dispersive solid-phase extraction followed by gas chromatography-tandem mass spectrometry.

    PubMed

    Tascone, Oriane; Shirshikova, Marina; Roy, Céline; Meierhenrich, Uwe J

    2014-12-01

    Damascena and centifolia roses are cultivated worldwide for their petal extracts that contain key odorant ingredients of perfumes. The analytical identification and quantification of pesticides in rose petals have never been described in the literature. Here, we report on a newly developed method using dispersive solid-phase extraction (d-SPE) cleanup followed by gas chromatography-tandem mass spectrometry for the quantitative determination of multi-residue pesticides in rose petals. Analytes were extracted from the matrix using acetonitrile and a mixture of salts containing magnesium sulfate, sodium citrate, sodium chloride, and sodium sesquihydrate. Samples were cleaned up twice by d-SPE applying primary and secondary amines (PSAs), magnesium sulfate, C18, and graphitized carbon black (GCB). Two fortification levels of 0.05 and 0.5 mg kg(-1) were assessed for method validation purposes. The obtained pesticide recoveries were in the range of 70-120 % with a relative standard deviation (RSD) of less than 20 %. The newly developed method was allowed for the quantification of 57 pesticides residues. It was applied to pesticide residue detection in rose petals from an organic field, without treatment, compared to those from a field with classic phytosanitary treatment using fungicide and/or insecticide. We did not detect pesticide residues in rose petals from the organic field. The classically treated samples of roses contained pesticides such as chlorpyriphos and methidathion which are in accordance with the previous application of these pesticides on the roses. Insecticides were quantified at 0.05 mg kg(-1) rose petal maximum. PMID:25344932

  7. Hexagonal boron nitride nanosheets as adsorbents for solid-phase extraction of polychlorinated biphenyls from water samples.

    PubMed

    Jia, Shiliang; Wang, Zhenhua; Ding, Ning; Elaine Wong, Y-L; Chen, Xiangfeng; Qiu, Guangyu; Dominic Chan, T-W

    2016-09-14

    The adsorptive potential of hexagonal boron nitride nanosheets (h-BNNSs) for solid-phase extraction (SPE) of pollutants was investigated for the first time. Seven indicators of polychlorinated biphenyls (PCBs) were selected as target analytes. The adsorption of PCBs on the surface of the h-BNNSs in water was simulated by the density functional theory and molecular dynamics. The simulation results indicated that the PCBs are adsorbed on the surface by π-π, hydrophobic, and electrostatic interactions. The PCBs were extracted with an h-BNNS-packed SPE cartridge, and eluted by dichloromethane. Gas chromatography-tandem mass spectrometry working in the multiple reaction monitor mode was used for the sample quantification. The effect of extraction parameters, including the flow rate, pH value, breakthrough volume, and the ionic strength, were investigated. Under the optimal working conditions, the developed method showed low limits of detection (0.24-0.50 ng L(-1); signal-to-noise ratio = 3:1), low limits of quantification (0.79-1.56 ng L(-1); signal-to-noise ratio = 10:1), satisfactory linearity (r > 0.99) within the concentration range of 2-1000 ng L(-1), and good precision (relative standard deviation < 12%). The PCBs concentration in environmental water samples was determined by the developed method. This results demonstrate that h-BNNSs have high analytical potential in the enrichment of pollutants. PMID:27566347

  8. Quantification of rosuvastatin in human plasma by automated solid-phase extraction using tandem mass spectrometric detection.

    PubMed

    Hull, C K; Penman, A D; Smith, C K; Martin, P D

    2002-06-01

    An assay employing automated solid-phase extraction (SPE) followed by high-performance liquid chromatography with positive ion TurboIonspray tandem mass spectrometry (LC-MS-MS) was developed and validated for the quantification of rosuvastatin (Crestor) in human plasma. Rosuvastatin is a hydroxy-methyl glutaryl coenzyme A reductase inhibitor currently under development by AstraZeneca. The standard curve range in human plasma was 0.1-30 ng/ml with a lower limit of quantification (LLOQ) verified at 0.1 ng/ml. Inaccuracy was less than 8% and imprecision less than +/-15% at all concentration levels. There was no interference from endogenous substances. The analyte was stable in human plasma following three freeze/thaw cycles and for up to 6 months following storage at both -20 and -70 degrees C. The assay was successfully applied to the analysis of rosuvastatin in human plasma samples derived from clinical trials, allowing the pharmacokinetics of the compound to be determined. PMID:12007766

  9. Determination of pinocembrin in human plasma by solid-phase extraction and LC/MS/MS: application to pharmacokinetic studies.

    PubMed

    Yan, Bei; Cao, Guoying; Sun, Taohua; Zhao, Xi; Hu, Xin; Yan, Jiling; Peng, Yueying; Shi, Aixin; Li, Yang; Xue, Wei; Li, Min; Li, Kexin; Liu, Yingfa

    2014-12-01

    A sensitive, fast and specific method for the quantitation of pinocembrin in human plasma based on high-performance liquid chromatography-tandem mass spectrometry (LC/MS/MS) was developed and validated. Clonazepam was used as the internal standard (IS). After solid-phase extraction of 500 μL plasma, pinocembrin and the IS were separated on a Luna C8 column using the mobile phase composed of acetonitrile-0.3 mm ammonium acetate solution (65:35, v/v) at a flow rate of 0.25 mL/min in isocratic mode. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring via an electrospray ionization source in negative mode by AB SCIEX Qtrap 5500. The assay was linear from 1 to 400 ng/mL, with within- and between-run accuracy (relative error) from -1.82 to 0.54%, and within- and between-run precision (CV) below 5.25%. The recovery was above 88% for the analyte at 1, 50 and 300 ng/mL. This analytical method was successful for the determination of pinocembrin in human plasma and applied to a pharmacokinetic study of pinocembrin injection in healthy volunteers after intravenous drip administration. PMID:24733513

  10. Surfacted ferrofluid based dispersive solid phase extraction; a novel approach to preconcentration of cationic dye in shrimp and water samples.

    PubMed

    Fasih Ramandi, Negin; Shemirani, Farzaneh

    2015-10-15

    Surfacted ferrofluid (S-FF) is a stable colloid dispersion of magnetic nanoparticles in a carrier liquid which possesses magnetic properties and fluidity simultaneously. Specifically in S-FF coating magnetic nanoparticles with a suitable surfactant provides steric repulsions to prevent particles agglomeration. Selecting the function of surfactant can be engineered according to its application. In the present study, for the first time the application of S-FF in dispersive solid phase extraction of methylene blue (as a cationic dye model) in water and shrimp samples was investigated. For this purpose, in order to use ionic liquid as carrier fluid, the surface of Fe3O4 nanoparticles was coated by an anionic surfactant in a polar medium to form a hydrophilic layer around magnetic nanoparticles. In addition to hydrophobic interactions between the analyte and carbonic chain of surfactant, the retention of cationic dye was mainly governed by attractive electrostatic interactions between polar head of surfactant and dye. Under optimized conditions, the relative standard deviation is 2.9%, the limit of detection is 2.5 μg L(-1), and the preconcentration factor is 135. PMID:25952885

  11. Study of the retention of benzotriazoles, benzothiazoles and benzenesulfonamides in mixed-mode solid-phase extraction in environmental samples.

    PubMed

    Salas, Daniela; Borrull, Francesc; Marcé, Rosa Maria; Fontanals, Núria

    2016-04-29

    In the present study, the capabilities of strong cation-exchange and strong anion-exchange sorbents for solid-phase extraction (SPE) have been evaluated for the selective retention of benzotriazoles (BTRs), benzothiazoles (BTs) and benzenesulfonamides (BSAs), which are a group of neutral analytes with interesting properties such as high polarity and the capability of delocalizing electron density. The retention of these analytes has been compared in both sorbents for the first time, using a SPE procedure specially designed to promote ionic retention of the analytes with the objective of including a washing step with an organic solvent to eliminate interferences retained by hydrophobic interactions. As a result, ionic interactions between the analytes and both sorbents were observed, which allowed the successful introduction of a washing step using methanol in the SPE procedure even when most of the analytes were in their neutral state under SPE conditions. Consequently, a method was developed and further validated for each sorbent using liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS). Apart from the development of an improved method, special attention was paid to the discussion of the interactions present between the sorbents and each group of analytes to explain how these analytes in their neutral state might develop ionic interactions with the sorbents. At the end, the use of these sorbents helped to simplify previous developed methods where hydrophobic/hydrophilic sorbents were used, obtaining enhanced results when evaluated in river water and effluent and influent wastewaters. PMID:27040512

  12. Preparation and characterization of porous DVB copolymers and their applicability for adsorption (solid-phase extraction) of phenol compounds

    NASA Astrophysics Data System (ADS)

    Sobiesiak, Magdalena; Podkoscielna, Beata

    2010-12-01

    Using DVB, three new porous copolymers in the form of microspheres were prepared, characterized and used as adsorbents for phenol and its chlorinated derivatives. As the monomers: 4,4'-bis(maleimidodiphenyl)methane (BM), 2,3-bis(2-hydroxy-3-methylacryloyloxy-propoxy)naphthalene (2,3-NAF) and 2,3-epoxypropyl methacrylate (GLY) were used. All the studied materials were synthesized under the same conditions by means of suspension copolymerization. The DVB copolymers were characterized by elemental analysis, FTIR spectroscopy, TG and DSC analyses and N 2 sorption. The off-line solid-phase extraction method (SPE) was used to estimate sorption properties of the copolymers. The results show that the newly obtained materials are mesoporous but their shape of pores and chemical structures are different. BM-DVB and GLY-DVB are characterized by slit-shaped pores and wide pore size distribution. 2,3-NAF-DVB also possesses slit pores but distribution of pore size is narrower. Of those studied BM-DVB is the most interesting material. It has good sorption properties and heat resistance.

  13. An enzymeless organophosphate pesticide sensor using Au nanoparticle-decorated graphene hybrid nanosheet as solid-phase extraction.

    PubMed

    Gong, Jingming; Miao, Xingju; Zhou, Ting; Zhang, Lizhi

    2011-09-15

    A sensitive enzymeless organophosphate pesticides (OPs) sensor is fabricated by using Au nanoparticles (AuNPs) decorated graphene nanosheets (GNs) modified glassy carbon electrode as solid phase extraction (SPE). Such a nanostructured composite film, combining the advantages of AuNPs with two dimensional GNs, dramatically facilitates the enrichment of nitroaromatic OPs onto the surface and realizes their stripping voltammetric detection of OPs by using methyl parathion (MP) as a model. The stripping voltammetric performances of captured MP were evaluated by cyclic voltammetric and square-wave voltammetric analysis. The combination of the nanoassembly of AuNPs-GNs, SPE, and stripping voltammetry provides a fast, simple, and sensitive electrochemical method for detecting nitroaromatic OPs. The stripping analysis is highly linear over the MP concentration ranges of 0.001-0.1 and 0.2-1.0 μg mL(-1) with a detection limit of 0.6 ng mL(-1). This designed enzymeless sensor exhibits good reproducibility and acceptable stability. PMID:21807193

  14. Coupling solid-phase extraction and enzyme-linked immunosorbent assay for ultratrace determination of herbicides in pristine water

    USGS Publications Warehouse

    Aga, D.S.; Thurman, E.M.

    1993-01-01

    Solid-phase extraction (SPE) and enzyme-linked immunosorbent assay (ELISA) were coupled for automated trace analysis of pristine water samples containing 2-chloro-4-ethylamino-6-isopropylamine-s-triazine (atrazine) and 2-chloro-2???,6???-diethyl-N-(methoxymethyl)acetanilide (alachlor). The isolation of the two herbicides on a C18-resin involved the selection of an elution solvent that both removes interfering substances and is compatible with ELISA. Ethyl acetate was selected as the elution solvent followed by a solvent exchange with methanol/water (20/80, % v/v). The SPE-ELISA method has a detection limit of 5.0 ng/L (5 ppt), >90% recovery, and a relative standard deviation of ??10%. The performance of a microtiter plate-based ELISA and a magnetic particle-based ELISA coupled to SPE was also evaluated. Although the sensitivity of the two ELISA methods was comparable, the precision using magnetic particles was improved considerably (??10% versus ??20%) because of the faster reaction kinetics provided by the magnetic particles. Finally, SPE-ELISA and isotope dilution gas chromatography/ mass spectrometry correlated well (correlation coefficient of 0.96) for lake-water samples. The SPE-ELISA method is simple and may have broader applications for the inexpensive automated analysis of other contaminants in water at trace levels.

  15. 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

  16. Automated solid-phase extraction coupled online with HPLC-FLD for the quantification of zearalenone in edible oil.

    PubMed

    Drzymala, Sarah S; Weiz, Stefan; Heinze, Julia; Marten, Silvia; Prinz, Carsten; Zimathies, Annett; Garbe, Leif-Alexander; Koch, Matthias

    2015-05-01

    Established maximum levels for the mycotoxin zearalenone (ZEN) in edible oil require monitoring by reliable analytical methods. Therefore, an automated SPE-HPLC online system based on dynamic covalent hydrazine chemistry has been developed. The SPE step comprises a reversible hydrazone formation by ZEN and a hydrazine moiety covalently attached to a solid phase. Seven hydrazine materials with different properties regarding the resin backbone, pore size, particle size, specific surface area, and loading have been evaluated. As a result, a hydrazine-functionalized silica gel was chosen. The final automated online method was validated and applied to the analysis of three maize germ oil samples including a provisionally certified reference material. Important performance criteria for the recovery (70-120 %) and precision (RSDr <25 %) as set by the Commission Regulation EC 401/2006 were fulfilled: The mean recovery was 78 % and RSDr did not exceed 8 %. The results of the SPE-HPLC online method were further compared to results obtained by liquid-liquid extraction with stable isotope dilution analysis LC-MS/MS and found to be in good agreement. The developed SPE-HPLC online system with fluorescence detection allows a reliable, accurate, and sensitive quantification (limit of quantification, 30 μg/kg) of ZEN in edible oils while significantly reducing the workload. To our knowledge, this is the first report on an automated SPE-HPLC method based on a covalent SPE approach. PMID:25709066

  17. [Preparation of a hydrophilic-lipophilic composite solid phase extraction material and application in food safety inspection].

    PubMed

    Bao, James Jianmin; Xie, Dan; Sun, Chaohui; Li, Youxin; Wang, Junju

    2013-09-01

    A copolymer of divinylbenzene and N-vinyl pyrrolidone (DVB-NVP) was synthesized for the purpose of solid phase extraction (SPE). Its performance as an SPE resin was evaluated using six model compounds having different polarities. Aqueous samples containing those compounds were applied to SPE cartridges containing the aforementioned copolymer as well as the classic C18 and Oasis HLB for comparison, and the SPE processed samples were analyzed by using high performance liquid chromatography (HPLC) for quantitation. Then, the copolymer DVB-NVP was sulfonated to modify the surface properties. The surface modified materials were used to analyse complex samples. The results showed that DVB-NVP had high recoveries for the six compounds ranging from 95.55% to 101.08% which were better than those of the C18 and were comparable to those of Oasis HLB. In applying to real samples, the recoveries for dimethyl phthalate, diethyl phthalate and dibutyl phthalate in liquor were 102.55%, 102.99% and 102.11%, with the RSDs of 2.11%, 1.69%, 0.79% respectively. Similarly, the recoveries for clonidine and cyproheptadine in pork were 89.23% and 91.42% with the RSDs of 8.21% and 8.86%, respectively. PMID:24392618

  18. Determination of five priority haloacetic acids by capillary electrophoresis with contactless conductivity detection and solid phase extraction preconcentration.

    PubMed

    Kubáň, Petr; Makarõtševa, Natalja; Kiplagat, Isaac K; Kaljurand, Mihkel

    2012-03-01

    A sensitive capillary electrophoretic separation method with contactless conductivity detection (C4D) for analysis of five priority haloacetic acids (HAA5) is presented. The analytes were baseline separated in an electrolyte composed of 20 mM 2-(N-Morpholino) ethanesulfonic acid (MES), 20 mM L-histidine (HIS), and 30 μM cetyltrimethylammonium bromide (CTAB) at pH 6.0 in less than 4 min. A simplified solid-phase extraction (SPE) preconcentration procedure on highly cross-linked polystyrene-divinylbenzene (PS-DVB) type sorbent was developed and optimized with respect to short preconcentration time. HAA5 from a 25-mL sample aliquot of tap and swimming pool water could be preconcentrated in less than 5 min using an in-house made SPE column with recoveries ranging from 23 to 98%. Combining the SPE preconcentration procedure with capillary electrophoretic analysis, the attained limits of detection were between 6.1 and 12.2 μg/L with total analysis time of less than 10 min. PMID:22517640

  19. Simultaneous determination of herbicide residues in tobacco using ultraperformance convergence chromatography coupled with solid-phase extraction.

    PubMed

    Guo, Weiyun; Bian, Zhaoyang; Zhang, Daohong; Tang, Gangling; Liu, Wei; Wang, Jianlong; Li, Zhonghao; Yang, Fei

    2015-03-01

    A time-saving and organic solvent efficient method to simultaneously determine six kinds of herbicide residues in tobacco using solid-phase extraction for sample clean-up and preconcentration and the highly sensitive ultraperformance convergence chromatography method was developed. Parameters for ultraperformance convergence chromatography, including the choice of stationary phase and modifiers, autobackpressure regulator pressure, column temperature, and the flow rate of mobile solvents, were optimized. The herbicide residues of napropamide, alachlor, quizalofop-ethyl, diphenamid, metolachlor, and clomazone in tobacco samples were successfully separated and detected at levels as low as 0.0043-0.0086 mg/kg within 5 min using a nonpolar high strength silica C18 selectivity for bases column and methanol as the cosolvent of the mobile phase of carbon dioxide (75-99.9%, v/v). Analysis of tobacco samples had recoveries of 69.8-95.0%, limit of quantitation of 0.0127-0.0245 mg/kg, limit of detection of 0.0043-0.0086 mg/kg, and correlation coefficient of >0.9990. Results support this method as an efficient alternative to current methodologies for the determination of herbicide residues in tobacco. PMID:25546570

  20. Selective isolation of hydrophobin SC3 by solid-phase extraction with polytetrafluoroethylene microparticles and subsequent mass spectrometric analysis.

    PubMed

    Kupčík, Rudolf; Zelená, Miroslava; Řehulka, Pavel; Bílková, Zuzana; Česlová, Lenka

    2016-02-01

    Hydrophobins are small proteins that play a role in a number of processes during the filamentous fungi growth and development. These proteins are characterized by the self-assembly of their molecules into an amphipathic membrane at hydrophilic-hydrophobic interfaces. Isolation and purification of hydrophobins generally present a challenge in their analysis. Hydrophobin SC3 from Schizophyllum commune was selected as a representative of class I hydrophobins in this work. A novel procedure for selective and effective isolation of hydrophobin SC3 based on solid-phase extraction with polytetrafluoroethylene microparticles loaded in a small self-made microcolumn is reported. The tailored binding of hydrophobins to polytetrafluoroethylene followed by harsh elution conditions resulted in a highly specific isolation of hydrophobin SC3 from the model mixture of ten proteins. The presented isolation protocol can have a positive impact on the analysis and utilization of these proteins including all class I hydrophobins. Hydrophobin SC3 was further subjected to reduction of its highly stable disulfide bonds and to chymotryptic digestion followed by mass spectrometric analysis. The isolation and digestion protocols presented in this work make the analysis of these highly hydrophobic and compact proteins possible. PMID:26608781

  1. Phosphopeptide enrichment: Development of magnetic solid phase extraction method based on polydopamine coating and Ti(4+)-IMAC.

    PubMed

    Piovesana, Susy; Capriotti, Anna Laura; Cavaliere, Chiara; Ferraris, Francesca; Samperi, Roberto; Ventura, Salvatore; Laganà, Aldo

    2016-02-25

    Protein post translational modifications currently represent one of the main challenges with proteomic analysis, due to the important biological role they play within cells. Protein phosphorylation is one of the most important, with several approaches developed for phosphopeptides enrichment and analysis, essential for comprehensive phosphoproteomic analysis. However, the development of new materials for phosphopeptides enrichment may overcome previous drawbacks and improve enrichment of such peptides. In this regard, new magnetic stationary phases based on polydopamine coating and Ti(4+) immobilization exploit the potential of IMAC enrichment and couple it with the versatility of magnetic solid phase extraction. In this work the use of such stationary phase was extended from the MALDI proof of concept stage with the development of an optimized method for phosphopeptides enrichment compatible with typical shotgun proteomics experimental workflows. Different loading and elution buffers were tested to improve phosphopeptides recovery and enrichment selectivity. Finally, the analysis of isolated peptides pointed out that polydopamine alone is an ideal support matrix for polar post translational modifications because it enables to reduce unspecific binding and preferentially binds hydrophilic peptides. PMID:26851086

  2. Polymer Microchips Integrating Solid Phase Extraction and High Performance Liquid Chromatography Using Reversed-Phase Polymethacrylate Monoliths

    PubMed Central

    Liu, Jikun; Chen, C. F.; Tsao, C. W.; Chang, C. C.; Chu, C. C.; DeVoe, D. L.

    2009-01-01

    Polymer microfluidic chips employing in situ photopolymerized polymethacrylate monoliths for high performance liquid chromatography separations of peptides is described. The integrated chip design employs a 15 cm long separation column containing a reversed-phase polymethacrylate monolith as a stationary phase, with its front end seamlessly coupled to a 5 mm long methacrylate monolith which functions as a solid phase extraction (SPE) element for sample cleanup and enrichment, serving to increase both detection sensitivity and separation performance. In addition to sample concentration and separation, solvent splitting is also performed on-chip, allowing the use of a conventional LC pump for the generation of on-chip nano-flow solvent gradients. The integrated platform takes advantage of solvent bonding and a novel high-pressure needle interface which together enable the polymer chips to withstand internal pressures above 20 MPa (~2,900 psi) for efficient pressure-driven HPLC separations. Gradient reversed-phase separation of fluorescein-labeled model peptides and BSA tryptic digest are demonstrated using the microchip HPLC system. On-line removal of free fluorescein and enrichment of labeled proteins are simultaneously achieved using the on-chip SPE column, resulting in a 150-fold improvement in sensitivity and a 10-fold reduction in peak width in the following microchip gradient LC separation. PMID:19267447

  3. Quantitative determination of 1,4-dioxane and tetrahydrofuran in groundwater by solid phase extraction GC/MS/MS.

    PubMed

    Isaacson, Carl; Mohr, Thomas K G; Field, Jennifer A

    2006-12-01

    Groundwater contamination by cyclic ethers, 1,4-dioxane (dioxane), a probable human carcinogen, and tetrahydrofuran (THF), a co-contaminant at many chlorinated solvent release sites, are a growing concern. Cyclic ethers are readily transported in groundwater, yet little is known about their fate in environmental systems. High water solubility coupled with low Henry's law constants and octanol-water partition coefficients make their removal from groundwater problematic for both remedial and analytical purposes. A solid-phase extraction (SPE) method based on activated carbon disks was developed for the quantitative determination of dioxane and THF. The method requires 80 mL samples and a total of 1.2 mL of solvent (acetone). The number of steps is minimized due to the "in-vial" elution of the disks. Average recoveries for dioxane and THF were 98% and 95%, respectively, with precision, as indicated by the relative standard deviation of <2% to 6%. The method quantitation limits are 0.31 microg/L for dioxane and 3.1 microg/L for THF. The method was demonstrated by analyzing groundwater samples for dioxane and THF collected during a single sampling campaign at a TCA-impacted site. Dioxane concentrations and areal extent of dioxane in groundwater were greater than those of either TCA or THF. PMID:17180982

  4. Measurement of Intracellular Ribavirin Mono-, Di- and Triphosphate Using Solid Phase Extraction and LC-MS/MS Quantification

    PubMed Central

    Jimmerson, Leah C.; Ray, Michelle L.; Bushman, Lane R.; Anderson, Peter L.; Klein, Brandon; Rower, Joseph E.; Zheng, Jia-Hua; Kiser, Jennifer J.

    2014-01-01

    Ribavirin (RBV) is a nucleoside analog used to treat a variety of DNA and RNA viruses. RBV undergoes intracellular phosphorylation to a mono- (MP), di- (DP), and triphosphate (TP). The phosphorylated forms have been associated with the mechanisms of antiviral effect observed in vitro, but the intracellular pharmacology of the drug has not been well characterized in vivo. A highly sensitive LC-MS/MS method was developed and validated for the determination of intracellular RBV MP, DP, and TP in multiple cell matrix types. For this method, the individual MP, DP, and TP fractions were isolated from lysed intracellular matrix using strong anion exchange solid phase extraction, dephosphorylated to parent RBV, desalted and concentrated and quantified using LC-MS/MS. The method utilized a stable labeled internal standard (RBV-13C5) which facilitated accuracy (% deviation within ±15%) and precision (coefficient of variation of ≤15%). The quantifiable linear range for the assay was 0.50 to 200 pmol/sample. The method was applied to the measurement of RBV MP, DP, and TP in human peripheral blood mononuclear cells (PBMC), red blood cells (RBC), and dried blood spot (DBS) samples obtained from patients taking RBV for the treatment of chronic Hepatitis C virus infection. PMID:25555148

  5. Colorimetric-Solid Phase Extraction Technology for Water Quality Monitoring: Evaluation of C-SPE and Debubbling Methods in Microgravity

    NASA Technical Reports Server (NTRS)

    Hazen-Bosveld, April; Lipert, Robert J.; Nordling, John; Shih, Chien-Ju; Siperko, Lorraine; Porter, Marc D.; Gazda, Daniel B.; Rutz, Jeff A.; Straub, John E.; Schultz, John R.; McCoy, J. Torin

    2007-01-01

    Colorimetric-solid phase extraction (C-SPE) is being developed as a method for in-flight monitoring of spacecraft water quality. C-SPE is based on measuring the change in the diffuse reflectance spectrum of indicator disks following exposure to a water sample. Previous microgravity testing has shown that air bubbles suspended in water samples can cause uncertainty in the volume of liquid passed through the disks, leading to errors in the determination of water quality parameter concentrations. We report here the results of a recent series of C-9 microgravity experiments designed to evaluate manual manipulation as a means to collect bubble-free water samples of specified volumes from water sample bags containing up to 47% air. The effectiveness of manual manipulation was verified by comparing the results from C-SPE analyses of silver(I) and iodine performed in-flight using samples collected and debubbled in microgravity to those performed on-ground using bubble-free samples. The ground and flight results showed excellent agreement, demonstrating that manual manipulation is an effective means for collecting bubble-free water samples in microgravity.

  6. New chelating reagents for preconcentration, separation, determination of metal complexes by high performance liquid chromatography and solid phase extraction

    SciTech Connect

    Qian, Yan wen.

    1991-12-03

    A general scheme is outlined for rapid determination of metal cations by complexation and subsequent HPLC separation. The synthesis and general properties are described for several new thiohydrazone chelating reagents. Solubility considerations suggest that the metal complexes have a positive charge. Excellent chromatographic separations are obtained for mixtures of up to seven metal complexes. Addition of a positively charged additive to the eluent is shown to have a significant effect on both the retention times and sharpness of the chromatographic peaks. Separation of the metal complexes on resins with a permanent charge is also shown to be feasible. Two new hydrazone reagents have been synthesized and characterized. Trace metal ions in aqueous solution are complexed by one of the hydrazones and the resulting metal complexes are solid phase extracted onto a mini cation-exchange or polymeric column. The uptake of metal complexes is complete and the elution step is fast and complete. The quantitative recoveries of metal ions determined by both spectrophotometric method and ICP-MS are very satisfactory and agree with each other.

  7. Automated and portable solid phase extraction platform for immuno-detection of 17β-estradiol in water.

    PubMed

    Heub, Sarah; Tscharner, Noe; Monnier, Véronique; Kehl, Florian; Dittrich, Petra S; Follonier, Stéphane; Barbe, Laurent

    2015-02-13

    A fully automated and portable system for solid phase extraction (SPE) has been developed for the analysis of the natural hormone 17β-estradiol (E2) in environmental water by enzyme linked immuno-sorbent assay (ELISA). The system has been validated with de-ionized and artificial sea water as model samples and allowed for pre-concentration of E2 at levels of 1, 10 and 100 ng/L with only 100 ml of sample. Recoveries ranged from 24±3% to 107±6% depending on the concentration and sample matrix. The method successfully allowed us to determine the concentration of two seawater samples. A concentration of 15.1±0.3 ng/L of E2 was measured in a sample obtained from a food production process, and 8.8±0.7 ng/L in a sample from the Adriatic Sea. The system would be suitable for continuous monitoring of water quality as it is user friendly, and as the method is reproducible and totally compatible with the analysis of water sample by simple immunoassays and other detection methods such as biosensors. PMID:25604269

  8. [Determination of three sweeteners in vinegars by solid phase extraction-high performance liquid chromatography/tandem mass spectrometry].

    PubMed

    Yin, Feng; Ding, Zhaowei; Cao, Xue; Gao, Jie; Jiang, Deming; Kuang, Denghui; Gu, Yanping; He, Guoliang

    2011-06-01

    A solid phase extraction-high performance liquid chromatography/electrospray ionization-tandem mass spectrometry (SPE-HPLC/ESI-MS/MS) method for the determination of 3 sweeteners (acesulfame (AK), sodium saccharin (SA), sodium cyclamate (SC)) in vinegars has been developed. The sample was diluted with acidic water, then purified and enriched with a weak anion exchange SPE column. The HPLC separation was performed on a Pursuit C18 column (150 mm x 2.0 mm, 3 microm) by gradient elution with 10 mmol/L ammonium acetate containing 0.1% (v/v) ammonia water and acetonitrile as the mobile phases. The analytes were detected by ESI--MS/MS in multiple reaction monitoring (MRM) mode to satisfy qualitative and quantitative detections. Good linearities (r2 > 0.99) were obtained over the range of 0.01 - 0.50 mg/L. The limits of quantification (LOQs) for SA, AK and SC were 10, 5 and 5 microg/kg, respectively. The average recoveries ranged from 72.1% to 96.8% at the spiked levels of 0.01 and 0.1 mg/L with the relative standard deviations (RSDs) less than 15%. This method is accurate, highly sensitive for qualitative and quantitative analysis of the 3 sweeteners in vinegars. PMID:22032168

  9. Analysis of volatile compositions of Magnolia biondii pamp by steam distillation and headspace solid phase micro-extraction.

    PubMed

    Zeng, Zhi; Xie, Runqian; Zhang, Tao; Zhang, Han; Chen, Jie Yu

    2011-01-01

    The chemical compositions of volatile components from Magnolia biondii Pamp were determined by steam distillation (SD) and headspace solid phase micro-extraction (HS-SPME) followed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analysis. Fifty-six compounds were identified and the major volatile components were d-camphor (0.18-43.26%), 1,8-cineol (13.23-38.02%), α-terpineol (6.57-12.29%) and α-cadinene (5.53-15.15%). The comparison of the volatile components from M. biondii Pamp harvested in three regions of China was investigated. Also, the comparison of volatile components by SD and HS-SPME methods in term of isolation time, plant-consuming and chemical compositions was discussed as well. The percentages of the volatile components by HS-SPME method were found to be large difference from the corresponding one by SD method. HS-SPME technique was much faster than SD (60 min (HS-SPME)/420 min (SD)). Although the aromatic profiles between HS-SPME and SD methods showed several quantitative differences, HS-SPME may be applied routinely to analyze aromatic and medicinal plants. PMID:22123239

  10. Potential of solid phase extraction disks to aid determination of dislodgeable foliar residues of chlorpyriphos, malathion, diazinon, and acephate.

    PubMed

    Snyder, J C; Thacker, R R; Boeniger, M; Antonious, G F

    2003-11-01

    The utility of solid phase extraction (SPE) for concentrating four organophosphate insecticides from solutions of water and sodium dioctyl sulfosuccinate, a surfactant, was evaluated. Reverse phase (C18, octadecyl bonded silica) sorbent in the form of a disk was the SPE medium evaluated. Chlorpyriphos, malathion, and diazinon, but not acephate, were retained on and eluted from the SPE disks. For pesticides that were retained on SPE disks, recoveries from the disks were equal to or higher than recoveries achieved by solvent partitioning. Dislodgeable foliar residues of acephate were successfully concentrated for analysis by lyophilization of water-surfactant solutions. Recoveries of pesticides from SPE disks stored at -15 degrees C for one week were equal to or higher than those of pesticides stored in water-surfactant for one week at -15 degrees C. Malathion- and diazinon-fortified samples in watersurfactant and on SPE disks were prepared in one state and shipped for analysis in another state. Pesticides in the water-surfactant samples were concentrated by solvent partitioning and were underestimated by 41% (diazinon) and 16% (malathion). Conversely, diazinon samples on the SPE disks were on average underestimated by 3% and malathion was overestimated by an average of 55%. The overestimation of malathion was attributed to a matrix effect during analysis associated with the presence of surfactant, which was retained on and subsequently eluted from the SPE disks. The retention of surfactant by the SPE disks and its subsequent elution may considerably limit their usefulness in determination of dislodgeable foliar residues. PMID:14708658

  11. Analysis of pesticides in soy milk combining solid-phase extraction and capillary electrophoresis-mass spectrometry.

    PubMed

    Hernández-Borges, Javier; Rodriguez-Delgado, Miguel Angel; García-Montelongo, Francisco J; Cifuentes, Alejandro

    2005-06-01

    In this work, the determination of a group of triazolopyrimidine sulfoanilide herbicides (cloransulam-methyl, metosulam, flumetsulam, florasulam, and diclosulam) in soy milk by capillary electrophoresis-mass spectrometry (CE-MS) is presented. The main electrospray interface (ESI) parameters (nebulizer pressure, dry gas flow rate, dry gas temperature, and composition of the sheath liquid) are optimized using a central composite design. To increase the sensitivity of the CE-MS method, an off-line sample preconcentration procedure based on solid-phase extraction (SPE) is combined with an on-line stacking procedure (i.e. normal stacking mode, NSM). Samples could be injected for up to 100 s, providing limits of detection (LODs) down to 74 microg/L, i.e., at the low ppb level, with relative standard deviation values (RSD,%) between 3.8% and 6.4% for peak areas on the same day, and between 6.5% and 8.1% on three different days. The usefulness of the optimized SPE-NSM-CE-MS procedure is demonstrated through the sensitive quantification of the selected pesticides in soy milk samples. PMID:16013821

  12. Fast and easy phosphopeptide fractionation by combinatorial ERLIC-SCX solid-phase extraction for in-depth phosphoproteome analysis.

    PubMed

    Zarei, Mostafa; Sprenger, Adrian; Rackiewicz, Michal; Dengjel, Joern

    2016-01-01

    Mass spectrometry-based phosphoproteomic analysis is a powerful method for gaining a global, unbiased understanding of cellular signaling. Its accuracy and comprehensiveness stands or falls with the quality and choice of the applied phosphopeptide prefractionation strategy. This protocol covers a powerful but simple and rapid strategy for phosphopeptide prefractionation. The combinatorial use of two distinct chromatographic techniques that address the inverse physicochemical properties of peptides allows for superior fractionation efficiency of multiple phosphorylated peptides. In the first step, multiphosphorylated peptides are separated according to the number of negatively charged phosphosites by electrostatic repulsion-hydrophilic interaction chromatography (ERLIC). A subsequent strong cation exchange (SCX) step separates mostly singly phosphorylated peptides in the ERLIC flow-through according to their positive charge. The presented strategy is inexpensive and adaptable to large and small amounts of starting material, and it allows highly multiplexed sample preparation. Because of its implementation as solid-phase extraction, the entire workflow takes only 2 h to complete. PMID:26633130

  13. Direct detection of Mycobacterium tuberculosis in sputum: A validation study using solid phase extraction-gas chromatography-mass spectrometry.

    PubMed

    Mourão, Marta P B; Kuijper, Sjoukje; Dang, Ngoc A; Walters, Elisabetta; Janssen, Hans-Gerd; Kolk, Arend H J

    2016-02-15

    Tuberculosis (TB) remains a worldwide health problem, especially in developing countries. Correct identification of Mycobacterium tuberculosis (MTB) infection is extremely important for providing appropriate treatment and care to patients. Here we describe a solid phase extraction-gas chromatography-mass spectrometry method (SPE-THM-GC-MS) for the detection of five biomarkers for M. tuberculosis. The method for classification is developed and validated through the analysis of 112 sputum samples from patients suspected of having TB. Twenty of twenty-five MTB culture-positive sputum samples were correctly classified as positive by our improved SPE-THM-GC-MS method. Eighty-five of eighty-seven MTB culture-negative samples were also negative by SPE-THM-GC-MS. The overall sensitivity of the new SPE-THM-GC-MS method is 80% (20/25) and the specificity is 98% (85/87) compared with culture. The method proved to be reliable and, although complex in principle, easy to operate due to the high degree of automation. PMID:26807702

  14. Simultaneous detection of trace metal ions in water by solid phase extraction spectroscopy combined with multivariate calibration

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Cao, Peng; Li, Wei; Tong, Peijin; Zhang, Xiaofang; Du, Yiping

    2016-04-01

    Solid Phase Extraction Spectroscopy (SPES) developed in this paper is a technique to measure spectrum directly on the solid phase material where the analytes are concentrated in SPE process. Membrane enrichment and UV-Visible spectroscopy were utilized to fulfill SPES, and multivariate calibration method of partial least squares (PLS) was used to simultaneously detect the concentrations of trace cobalt (II) and zinc (II) in water samples. The proposed method is simple, sensitive and selective. The complexes of analyte ions were collected on the cellulose acetate membranes via membrane filtration after the complexation reaction with 1-2-pyridylazo 2-naphthol (PAN). The spectra of the membranes which contained the complexes of metal ions and PAN were measured directly without eluting. The analytical conditions including pH, reaction time, sample volume, the amount of PAN, and flow rates were optimized. Nonionic surfactant Brij-30 was absorbed on the membranes prior to SPES to modify the membranes for improving the enrichment and spectrum measurement. The interference from other ions to the determination was investigated. Under the optimal condition, the absorbance was linearly related to the concentration at the range of 0.1-3.0 μg/L and 0.1-2.0 μg/L, with the correlation coefficients (R2) of 0.9977 and 0.9951 for Co (II) and Zn (II), respectively. The limits of detection were 0.066 μg/L for cobalt (II) and 0.104 μg/L for zinc (II). PLS regression with leave-one-out cross-validation was utilized to build models to detect cobalt (II) and zinc (II) in drinking water samples simultaneously. The correlation coefficient between ion concentration and spectrum of calibration set and independent prediction set were 1.0000 and 0.9974 for cobalt (II) and 1.0000 and 0.9956 for zinc (II). For cobalt (II) and zinc (II), the errors of the prediction set were in the range 0.0406-0.1353 μg/L and 0.0025-0.1884 μg/L.

  15. Simultaneous detection of trace metal ions in water by solid phase extraction spectroscopy combined with multivariate calibration.

    PubMed

    Wang, Lei; Cao, Peng; Li, Wei; Tong, Peijin; Zhang, Xiaofang; Du, Yiping

    2016-04-15

    Solid Phase Extraction Spectroscopy (SPES) developed in this paper is a technique to measure spectrum directly on the solid phase material where the analytes are concentrated in SPE process. Membrane enrichment and UV-Visible spectroscopy were utilized to fulfill SPES, and multivariate calibration method of partial least squares (PLS) was used to simultaneously detect the concentrations of trace cobalt (II) and zinc (II) in water samples. The proposed method is simple, sensitive and selective. The complexes of analyte ions were collected on the cellulose acetate membranes via membrane filtration after the complexation reaction with 1-2-pyridylazo 2-naphthol (PAN). The spectra of the membranes which contained the complexes of metal ions and PAN were measured directly without eluting. The analytical conditions including pH, reaction time, sample volume, the amount of PAN, and flow rates were optimized. Nonionic surfactant Brij-30 was absorbed on the membranes prior to SPES to modify the membranes for improving the enrichment and spectrum measurement. The interference from other ions to the determination was investigated. Under the optimal condition, the absorbance was linearly related to the concentration at the range of 0.1-3.0 μg/L and 0.1-2.0 μg/L, with the correlation coefficients (R(2)) of 0.9977 and 0.9951 for Co (II) and Zn (II), respectively. The limits of detection were 0.066 μg/L for cobalt (II) and 0.104 μg/L for zinc (II). PLS regression with leave-one-out cross-validation was utilized to build models to detect cobalt (II) and zinc (II) in drinking water samples simultaneously. The correlation coefficient between ion concentration and spectrum of calibration set and independent prediction set were 1.0000 and 0.9974 for cobalt (II) and 1.0000 and 0.9956 for zinc (II). For cobalt (II) and zinc (II), the errors of the prediction set were in the range 0.0406-0.1353 μg/L and 0.0025-0.1884 μg/L. PMID:26845581

  16. Magnetic mixed hemimicelles solid-phase extraction coupled with high-performance liquid chromatography for the extraction and rapid determination of six fluoroquinolones in environmental water samples.

    PubMed

    Wang, Li; Yuan, Qiuxiang; Liang, Guoxi; Shi, Longbiao; Zhan, Qian

    2015-03-01

    In this study, a mixed hemimicelle solid-phase extraction method based on Fe3 O4 nanoparticles coated with sodium dodecyl sulfate was applied for the preconcentration and fast isolation of six fluoroquinolones in environmental water samples before high-performance liquid chromatography determination. The main factors affecting the extraction efficiency of the analytes, such as amount of surfactant, amount of Fe3 O4 nanoparticles, extraction time, sample volume, sample pH, ionic strength, and desorption conditions, were investigated and optimized. The method has detection limits from 0.05 to 0.1 ng/mL and good linearity (r ≥ 09948) in the range 0.1-200 ng/mL depending on the fluoroquinolone. The enrichment factor is ∼200. The recoveries (at spiked levels of 1, 5, and 50 ng/mL) are in the range of 79-120%. PMID:25581496

  17. Determination of chlorinated phenoxyacid herbicides in water and sediment by solid phase extraction and high-performance liquid chromatography. Final report

    SciTech Connect

    Myers, K.F.

    1992-11-01

    U.S. Environmental Protection Agency (USEPA) regulations require monitoring of chlorinated phenoxyacid herbicides such as 2,4-D, 2,4,5-T, and silvex in groundwater, drinking water, and wastes. Established analytical methods are time-consuming, can be hazardous, and often yield poor recoveries in routine laboratory use. This report describes a procedure for extraction of these compounds from sediment and water using solid phase extraction with analysis by high-performance liquid chromatography. This procedure yields reproducible results with recoveries of greater than 50 percent and method detection limits well below the criteria required by USEPA. Because of the nature of the extraction, this procedure can be used with a savings in preparation time, labor, and health risk.... Chlorinated phenoxyacid herbicides, Solid phase extraction, HPLC, 2,4-D, Silvex, 2,4,5-T.

  18. All-in-one solid-phase microextraction: Development of a selective solid-phase microextraction fiber assembly for the simultaneous and efficient extraction of analytes with different polarities.

    PubMed

    Gharari, Hossein; Farjaminezhad, Manoochehr; Marefat, Abdolrahim; Fakhari, Ali Reza

    2016-05-01

    In the present work, for the first time, an all-in-one solid-phase microextraction technique was developed for the simultaneous and efficient extraction of analytes within a vast polarity range. A novel fiber assembly composed of two different steel components each coated with different coatings (polydimethylsiloxane and polyethylene glycol) in terms of polarity by sol-gel technology was employed for the extraction of model compounds of different polarity in a single run followed by gas chromatography with mass spectrometry. Effective parameters in the extraction step and gas chromatography with mass spectrometry analysis were optimized for all model compounds. The detection limits of the developed method for model compounds were below 0.2 ng/L. The repeatability and reproducibility of the proposed method, explained by relative standard deviation, varied between 7.22 and 9.15% and between 7.95 and 14.90 (n = 5), respectively. Results showed that, under random conditions, compared to separate extractions performed by two other differently end-coated components that had not been assembled as the final dual fiber, as two individual fibers; simultaneous, efficient and relatively selective extraction of all model compounds was obtained in a single run by the proposed all-in-one technique. Finally, the optimized procedure was applied to extraction and determination of the model compounds in spiked water samples. PMID:27027718

  19. In-line micro-matrix solid-phase dispersion extraction for simultaneous separation and extraction of Sudan dyes in different spices.

    PubMed

    Rajabi, Maryam; Sabzalian, Sedigheh; Barfi, Behruz; Arghavani-Beydokhti, Somayeh; Asghari, Alireza

    2015-12-18

    A novel, simple, fast, and miniaturized method, termed in-line micro-matrix solid-phase dispersion (in-line MMSPD), coupled with high performance liquid chromatography (HPLC) was developed for the simultaneous extraction and determination of Sudan dyes (i.e. Sudan I-IV, Sudan orange G, Sudan black B, and Sudan red G) with the aid of an experimental design strategy. In this method, a matrix solid-phase dispersion (MSPD) column including a suitable mixture of polar sorbents was inserted in the mobile phase pathway, and while the interfering compounds were retained, the analytes were eluted and entered into the analytical column. In this way, the extraction, elution, and separation of the analytes were performed sequentially. Under the optimal experimental conditions (including the amount of sample, 0.0426g; amount of dispersant phase, 0.0216g of florisil, 0.0227g of silica, 0.0141g of alumina; and blending time, 112s), the limits of detection (LODs), limits of quantification, linear dynamic ranges, and recoveries were obtained to be 0.3-15.3μgkg(-1), 1-50μgkg(-1), 50-28,000μgkg(-1), and 94.5-99.1%, respectively. The results obtained showed that determination of the selected Sudan dyes in food samples using an enough sensitive and a simple analytically validated method like in-line MMSPD may offer a suitable screening method, which could be useful for food analysis and adulteration. PMID:26614171

  20. Determination of malachite green in fish based on magnetic molecularly imprinted polymer extraction followed by electrochemiluminescence.

    PubMed

    Huang, Baomei; Zhou, Xibin; Chen, Jing; Wu, Guofan; Lu, Xiaoquan

    2015-09-01

    A novel procedure for selective extraction of malachite green (MG) from fish samples was set up by using magnetic molecularly imprinted polymers (MMIP) as the solid phase extraction material followed by electrochemiluminescence (ECL) determination. MMIP was prepared by using Fe3O4 magnetite as magnetic component, MG as template molecule, methacrylic acid (MAA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as crosslinking agent. MMIP was characterized by SEM, TEM, FT-IR, VSM and XRD. Leucomalachite green (LMG) was oxidized in situ to MG by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). And then MMIP was successfully used to selectively enrich MG from fish samples. Adsorbed MG was desorbed and determined by ECL. Under the optimal conditions, calibration curve was good linear in the range of 0.29-290 μg/kg and the limit of detection (LOD) was 7.3 ng/kg (S/N=3). The recoveries of MMIP extraction were 77.1-101.2%. In addition, MMIP could be regenerated. To the best of our knowledge, MMIP coupling with ECL quenching of Ru(bpy)3(2+)/TPA for the determination of MG has not yet been developed. PMID:26003716

  1. Simultaneous determination of seven nitroimidazole residues in meat by using HPLC-UV detection with solid-phase extraction.

    PubMed

    Sun, Han-Wen; Wang, Feng-Chi; Ai, Lian-Feng

    2007-10-01

    A method was developed for the determination of the seven nitroimidazoles including metronidazole (MNZ), ronidazole (RNZ), dimetridazole (DMZ), tinidazole (TNZ), ornidazole (ONZ), secnidazole (SNZ) and the common metabolite of RNZ and hydroxydimetridazole (DMOHZ) in poultry and pork muscles by high-performance liquid chromatography (HPLC) with ultraviolet detection (UV). After extraction with ethyl acetate and evaporation, the nitroimidazoles were redissolved in ethyl acetate and purified using strong cation exchange (SCX) solid-phase extraction (SPE) column. The HPLC separation was carried through on a C(18) bonded silica column with a deionized water-methanol-acetonitrile mobile phase using a gradient elution procedure. The limit of detection of all the seven nitroimidazoles was 0.2 microg/kg. The recoveries of the seven nitroimidazoles for chicken, pork and bacon samples spiked with 1-20 microg/kg were in the range of 71.4-99.5%. The linearity is satisfactory with a correlation coefficient of >0.998 at concentrations ranging from 0.7 to 60 microg/kg. The relative standard deviations of 10 measurements for spiked chicken, pork and bacon samples at the concentration of 1 and 20 microg/kg were in the range of 6.2-13.9% and 4.0-8.7%, respectively. The intra-day precision (n=5) for nitroimidazoles residues in chicken spiked at 20 microg/kg is 6.9%, and the inter-day precision for 5 days (n=25) is 11%. The method is capable of identifying nitroimidazole residues at > or =0.7 microg/kg levels and was applied in the determination of nitroimidazole residues in meat sample. PMID:17719280

  2. Stabilization of Sulfur and Arsenic Species in Sulfidic, Iron-rich Geothermal Waters Using Solid Phase Extraction

    NASA Astrophysics Data System (ADS)

    Ullrich, M. K.; Gayout, A.; Misiari, V.; Planer-Friedrich, B.

    2015-12-01

    Iron-rich geothermal waters pose a special challenge regarding sample stabilization for sulfur and arsenic speciation analysis. Standard stabilization techniques fail to preserve speciation due to precipitating iron oxyhydroxides and thus adsorption of arsenic when flash-freezing a sample or precipitation of orpiment (As2S3)-like phases when adding HNO3. Solid phase extraction has the potential to extract anionic sulfur and arsenic species from solution and consequently separate them from cationic iron. This method was tested by applying synthetic solutions of sulfur and arsenic species onto Bio-Rad AG2-X8 resin and eluting the target species using 0.5 M Na-Salicylate. Complete retention of the initially applied amount on the resin was found for sulfate, thiosulfate, arsenate, monothioarsenate and trithioarsenate with 100.0 %, 99.7 %, 95.1 %, 98.9 %, and 99.8 %, respectively. Arsenite passed the resin without binding (3.0 % retention). All species bound to the resin could be eluted quantitatively and species-conserving with a recovery of 98.4 %, 102.8 %, 95.3 %, 90.5 % and 85.3 % for sulfate, thiosulfate, arsenate, monothioarsenate and trithioarsenate, respectively. Addition of 5 ppm FeCl2 did not reduce method efficiency with 98.7 % retention and 105.1 % recovery for monothioarsenate, while all of the applied iron passed the resin without binding as hypothesized. However, in solutions containing a mixture of arsenite, arsenate, monothioarsenate and trithioarsenate we found arsenite retention up to 59.1 % both in the presence and absence of iron. This effect cannot be fully explained yet and might be attributed to free sulfide in these mixed solutions facilitating arsenite binding via sulfide sorbed onto the resin. The interaction between different species needs to be further investigated. Samples from geothermal features in Yellowstone and mineral springs in the Czech Republic have been collected and results of immediate elution and stability during storage will

  3. Determination of quinolones in milk samples using a combination of magnetic solid-phase extraction and capillary electrophoresis.

    PubMed

    Ibarra, Israel S; Rodriguez, Jose A; Páez-Hernández, Ma Elena; Santos, Eva M; Miranda, Jose M

    2012-07-01

    A magnetic solid-phase extraction (MSPE) method combined with capillary electrophoresis for the simultaneous determination of seven quinolones (QNs) (danofloxacin, ciprofloxacin, marbofloxacin, enrofloxacin, difloxacin, oxolinic acid, and flumequine), using (S)-(+)-6-methoxy-α-methyl-2-naphthaleneacetic acid as internal standard, in milk samples was developed. The variables involved in the preconcentration magnetic procedure were: the composition of the magnetic support composition, the sample pH, and the weight of magnetic adsorbent used. The variables were optimized using a simplex-lattice design. Different magnetite covered with octyl-phenyl silica adsorbents were synthesized by varying the molar ratio of phenyltrimethylsilane and octyltrimethoxysilane; the solids were evaluated for QN preconcentration. Under optimal conditions, a linear range was obtained from 27 to 1000 μg L(-1) with limits of detection ranging from 9 to 12 μg L(-1) for the seven QNs. The absolute recoveries of the seven QNs at three different spiked levels (40, 150, and 400 μg L(-1) ) ranged from 74% to 98% with a relative standard deviation less than 10% in all cases. The proposed method was applied to analyze 20 whole milk samples of different brands. All samples were positive for the presence of QN residues; in some cases, extract dilution was required. The concentrations found are in the range from 31.1 to 5047.3 μg L(-1) . Marbofloxacin was the most frequently found. The method proposed offers advantages in terms of simplicity, sensitivity, efficiency, cost, and analysis time making it an alternative for the analysis of QNs in whole milk samples. PMID:22806471

  4. Analysis of Mars Analogue Soil Samples Using Solid-Phase Microextraction, Organic Solvent Extraction and Gas Chromatography/Mass Spectrometry

    NASA Technical Reports Server (NTRS)

    Orzechowska, G. E.; Kidd, R. D.; Foing, B. H.; Kanik, I.; Stoker, C.; Ehrenfreund, P.

    2011-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are robust and abundant molecules in extraterrestrial environments. They are found ubiquitously in the interstellar medium and have been identified in extracts of meteorites collected on Earth. PAHs are important target molecules for planetary exploration missions that investigate the organic inventory of planets, moons and small bodies. This study is part of an interdisciplinary preparation phase to search for organic molecules and life on Mars. We have investigated PAH compounds in desert soils to determine their composition, distribution and stability. Soil samples (Mars analogue soils) were collected at desert areas of Utah in the vicinity of the Mars Desert Research Station (MDRS), in the Arequipa region in Peru and from the Jutland region of Denmark. The aim of this study was to optimize the solid-phase microextraction (SPME) method for fast screening and determination of PAHs in soil samples. This method minimizes sample handling and preserves the chemical integrity of the sample. Complementary liquid extraction was used to obtain information on five- and six-ring PAH compounds. The measured concentrations of PAHs are, in general, very low, ranging from 1 to 60 ng g(sup -1). The texture of soils is mostly sandy loam with few samples being 100% silt. Collected soils are moderately basic with pH values of 8-9 except for the Salten Skov soil, which is slightly acidic. Although the diverse and variable microbial populations of the samples at the sample sites might have affected the levels and variety of PAHs detected, SPME appears to be a rapid, viable field sampling technique with implications for use on planetary missions.

  5. Analysis of Mars analogue soil samples using solid-phase microextraction, organic solvent extraction and gas chromatography/mass spectrometry

    NASA Astrophysics Data System (ADS)

    Orzechowska, G. E.; Kidd, R. D.; Foing, B. H.; Kanik, I.; Stoker, C.; Ehrenfreund, P.

    2011-07-01

    Polycyclic aromatic hydrocarbons (PAHs) are robust and abundant molecules in extraterrestrial environments. They are found ubiquitously in the interstellar medium and have been identified in extracts of meteorites collected on Earth. PAHs are important target molecules for planetary exploration missions that investigate the organic inventory of planets, moons and small bodies. This study is part of an interdisciplinary preparation phase to search for organic molecules and life on Mars. We have investigated PAH compounds in desert soils to determine their composition, distribution and stability. Soil samples (Mars analogue soils) were collected at desert areas of Utah in the vicinity of the Mars Desert Research Station (MDRS), in the Arequipa region in Peru and from the Jutland region of Denmark. The aim of this study was to optimize the solid-phase microextraction (SPME) method for fast screening and determination of PAHs in soil samples. This method minimizes sample handling and preserves the chemical integrity of the sample. Complementary liquid extraction was used to obtain information on five- and six-ring PAH compounds. The measured concentrations of PAHs are, in general, very low, ranging from 1 to 60 ng g-1. The texture of soils is mostly sandy loam with few samples being 100 % silt. Collected soils are moderately basic with pH values of 8-9 except for the Salten Skov soil, which is slightly acidic. Although the diverse and variable microbial populations of the samples at the sample sites might have affected the levels and variety of PAHs detected, SPME appears to be a rapid, viable field sampling technique with implications for use on planetary missions.

  6. Multi-component analysis of polar water pollutants using sequential solid-phase extraction followed by LC-ESI-MS.

    PubMed

    Loos, Robert; Hanke, Georg; Eisenreich, Steven J

    2003-06-01

    A multi-component screening analysis method for polar to medium-polar water pollutants was developed. Sample clean-up and group separation are performed by sequential solid-phase extraction (SSPE) using automated SPE with C18 and polymeric sorbent materials. Analyses are performed by liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS) using a single-quadrupole instrument. More than 90 priority compounds of environmental interest--comprising the most important chemical and substance classes: phenols, carboxylic acids, aromatic sulfonates, aromatic amines, pharmaceuticals, surfactants, dyes, and pesticides--have been chosen for the experiments. The compounds are divided by the SSPE procedure into 3 different polarity classes. The extraction recoveries were determined in the 3 fractions for every single substance, and were for most of the analytes in the range of 50-100%. A mixture of hexane-dichloromethane was used for the elution of nonpolar compounds like alkylphenols from C18. Methanol and acetone are well suited for the elution of more polar substances. The limits of detection (LODs) were determined for all compounds. Effluents from municipal and industrial wastewater treatment plants (WWTPs) treating waste water from textile industries; and the corresponding receiving waters (rivers and lakes) have been analysed with the developed method. Urban and industrial pollution was observed in rivers and streams in the area north of Milan, Italy. In the water samples different phenols (nitrophenols, bisphenol A, nonylphenol), alkylphenol ethoxylate surfactants, their metabolites with endocrine disrupting potential, aromatic sulfonates, linear alkylbenzenesulfonate surfactants, dyes, pesticides, pharmaceuticals, and a dichlorobenzidine compound were identified. PMID:12833980

  7. Simultaneous determination of rivanol and mifepristone in human plasma by a HPLC-UV method with solid-phase extraction.

    PubMed

    Guo, Zhiyong; Wei, Danyi; Yin, Gengxin; Wang, Sui; Zhao, Shasha; Chu, Yun; Zhai, Jinxia

    2007-09-01

    A HPLC method with UV detection was developed and validated for the simultaneous determination of rivanol and mifepristone in human plasma. Norethisterone was used as the internal standard. Separation was performed by a C18 reversed-phase column maintained at 20 degrees C. The mobile phase was a mixture of methanol-acetonitrile-0.05% sodium dodecylsulfonate in a 0.05 M phosphate buffer with the pH adjusted to 3.0 (30:30:40, v/v/v) at a flow rate of 0.8 ml/min. Dual wavelength mode was used, with mifepristone monitored at UV 302 nm, while rivanol and norethisterone at 272 nm. A reliable biological sample pre-treatment procedure by means of solid-phase extraction was used, which allowed to obtain good extraction efficiency (>93%) for both of the analytes and the internal standard. The calibration curves were both linear with the correlation coefficient r equal to 0.9999. For rivanol, the assay gave CV% values for precision always lower than 7.8% and mean accuracy values higher than 95.3%. As to mifepristone, precision was always lower than 10.1% and mean accuracy values were higher than 93.8%. The limit of detection for the assay of rivanol and mifepristone was 1.1 and 3 ng/ml, respectively. The method is simple, sensitive and accurate, and allow for simultaneous determination of nanogram levels of rivanol and mifepristone in human plasma. It could be applied to assess the plasma level of rivanol and mifepristone in women undergoing polypharmacy with the two drugs. PMID:17689304

  8. Rapid, specific determination of iodine and iodide by combined solid-phase extraction/diffuse reflectance spectroscopy

    NASA Technical Reports Server (NTRS)

    Arena, Matteo P.; Porter, Marc D.; Fritz, James S.

    2002-01-01

    A new, rapid methodology for trace analysis using solid-phase extraction is described. The two-step methodology is based on the concentration of an analyte onto a membrane disk and on the determination by diffuse reflectance spectroscopy of the amount of analyte extracted on the disk surface. This method, which is adaptable to a wide range of analytes, has been used for monitoring ppm levels of iodine and iodide in spacecraft water. Iodine is used as a biocide in spacecraft water. For these determinations, a water sample is passed through a membrane disk by means of a 10-mL syringe that is attached to a disk holder assembly. The disk, which is a polystyrene-divinylbenzene composite, is impregnated with poly(vinylpyrrolidone) (PVP), which exhaustively concentrates iodine as a yellow iodine-PVP complex. The amount of concentrated iodine is then determined in only 2 s by using a hand-held diffuse reflectance spectrometer by comparing the result with a calibration curve based on the Kubelka-Munk function. The same general procedure can be used to determine iodide levels after its facile and exhaustive oxidation to iodine by peroxymonosulfate (i.e., Oxone reagent). For samples containing both analytes, a two-step procedure can be used in which the iodide concentration is calculated from the difference in iodine levels before and after treatment of the sample with peroxymonosulfate. With this methodology, iodine and iodide levels in the 0.1-5.0 ppm range can be determined with a total workup time of approximately 60 s with a RSD of approximately 6%.

  9. Screening for total ergot alkaloids in rye flour by planar solid phase extraction-fluorescence detection and mass spectrometry.

    PubMed

    Oellig, Claudia; Melde, Tina

    2016-04-01

    The analysis of ergot alkaloids is generally performed by high-performance liquid chromatography (HPLC) coupled to fluorescence detection (FLD) or mass selective detection. As for monitoring only the sum of ergot alkaloids is relevant, a fast and easy screening method for the determination of the total alkaloid content was developed using planar solid phase extraction (pSPE). Applying pSPE, recently introduced for pesticide residue analysis in fruits and vegetables (Oellig and Schwack, 2011) and tea (Oellig and Schwack, 2012), all ergot alkaloids are concentrated in a target zone followed by detection as the sum. The herein presented method includes an ammonium acetate buffered extraction step, followed by a fast liquid-liquid partitioning pre-cleaning before pSPE is performed on high-performance thin-layer chromatography (HPTLC) amino plates with a single methanol development to separate the ergot alkaloids from the remaining matrix and to collect them in a single zone. For quantitation, the native fluorescence was used after dipping the plate in n-hexane/paraffin solution for fluorescence enhancement. Limits of detection and quantitation of 0.07 and 0.24 mg/kg rye, respectively, expressed as ergocristine, were well below the currently applied quality criterion limit for rye. Near-100% recoveries were obtained at relevant spiking levels for different rye flour samples. Hence, the fast pSPE-FLD is an efficient and reliable method to screen for the total ergot alkaloid content in rye and a rapid alternative to the HPLC determination of individual alkaloids and to summing them up. HPTLC-MS additionally enables the identification of the ergot alkaloid composition by a single mass spectrum, when utilized as a fingerprint, offering an easy differentiation of Secale cornutum from different origins. PMID:26947163

  10. Combined solid-phase extraction and gas chromatography-mass spectrometry used for determination of chloropropanols in water.

    PubMed

    González, Paula; Racamonde, Inés; Carro, Antonia M; Lorenzo, Rosa A

    2011-10-01

    A sensitive and rapid derivatization method for the simultaneous determination of 1,3-dichloro-2-propanol (1,3-DCP) and 3-chloropropane-1,2-diol (3-MCPD) in water samples has been developed. The aim was to research the optimal conditions of the derivatization process for two selected reagents. A central composite design was used to determine the influence of derivatization time, derivatization temperature and reagent volume. A global desirability function was applied for multi-response optimization. The analysis was performed by gas chromatography-mass spectrometry. During the optimization of the extraction procedure, four different types of solid-phase extraction (SPE) columns were tested. It was demonstrated that the Oasis HLB cartridge produced the best recoveries of the target analytes. The pH value and the salinity were investigated using a Doehlert design. The best results for the SPE of both analytes were obtained with 1.5 g of NaCl and pH 6. The proposed method provides high sensitivity, good linearity (R(2)≥0.999) and repeatability (relative standard deviations % between 2.9 and 3.4%). Limits of detection and quantification were in the range of 1.4-11.2 ng/mL and 4.8-34.5 ng/mL, respectively. Recoveries obtained for water samples were ca. 100% for 1,3-DCP and 3-MCPD. The method has been successfully applied to the analysis of different samples including commercially bottled water, an influent and effluent sewage. PMID:21818849

  11. 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

  12. Preparation of a concentric layered structure of an electrospun nanofiber column for solid-phase extraction of mass viscous crude extracts.

    PubMed

    Qiu, Jinli; Yan, Yan; Chang, Hong; Liu, Xiongwei; Kang, Xuejun

    2016-06-01

    The packed nanofiber solid-phase extraction of crude extracts of a mass viscous sample is challenging because the interference and recalcitrant particulates in the sample may attach to the nanofiber and block the column, which leads to insufficient sample extraction. A novel concentric layered nanofiber solid-phase extraction (SPE) column using polystyrene-based electrospun nanofiber as the stationary phase has been employed for the pretreatment of mass viscous crude extracts. The layered column was fabricated by using untouched nanofiber with its natural morphology rather than hand-packing of spoiled fiber to the control packing density of the column. In the novel column, the SPE packed bed was divided into a multi-layer structure to provide uniform radial and axial packing and to part the mobile phase stream by the isolated layer with great superiority in aspects such as lower column pressure and faster elution speed. The feasibility and efficiency of the LFSPE column were then evaluated via determination of rhodamine B (RB) from spiked chili samples. Based on the LFSPE column, a linear spiked calibration curve in the range of 0.02-5 mg/kg was obtained. The limit of detection (LOD) and limit of quantification (LOQ) of the method were 0.001 and 0.004 mg/kg, respectively; recoveries at 0.1, 1, and 2 mg/kg (n = 3) were all up to 95 %; and the RSD values of inter-day and intra-day were all below 5 %. This novel LFSPE column overcame heterogeneous packing and exploited the wall effect in subtle ways, and exhibited great superiority by comparison with some existing methods. Graphical Abstract ᅟ. PMID:27086018

  13. High-throughput dynamic microwave-assisted extraction on-line coupled with solid-phase extraction for analysis of nicotine in mushroom.

    PubMed

    Wang, Hui; Zhao, Qi; Song, Weitao; Xu, Yang; Zhang, Xiaopan; Zeng, Qinglei; Chen, Haiyan; Ding, Lan; Ren, Nanqi

    2011-07-15

    A simple and low-cost high-throughput dynamic microwave-assisted extraction (HTDMAE) device was firstly assembled and validated by the extraction of nicotine in mushroom samples. In this device, a household microwave oven was applied to provide the microwave energy; a vacuum pump was used to deliver the solvent. Compared with traditional dynamic microwave-assisted extraction method, the sample throughput and microwave energy utilization were improved by the HTDMAE, up to 20 samples could be treated simultaneously in 9 min. Taking extraction of nicotine in mushroom sample as an example, a method was established with extraction, separation and enrichment of nicotine in a single step by the device on-line coupled with solid-phase extraction (SPE). Nicotine was first extracted from the mushroom samples with water under the action of microwave energy, and then directly introduced into the SPE column which was packed with cation-exchange resins. Subsequently, the nicotine trapped on the resins was eluted with methanol-ammonia (95:5, v/v) and determined by high-performance liquid chromatography. The limit of detection of nicotine obtained is 5.6 μg kg(-1) in fresh mushroom sample. The recovery of nicotine in mushroom samples is in the range of 87.4-104.0%. The proposed method which significantly reduced the overall analysis time and increased sample throughput should be favored for routine analyse of complex solid sample. PMID:21645768

  14. Magnetic solid-phase extraction of brominated flame retardants from environmental waters with graphene-doped Fe3O4 nanocomposites.

    PubMed

    Yang, Jing; Qiao, Jun-qin; Cui, Shi-hai; Li, Jia-yuan; Zhu, Jin-jin; Yin, He-xing; Zhan, Cheng-yan; Lian, Hong-zhen

    2015-06-01

    Graphene-doped Fe3O4 nanocomposites were prepared by a solvothermal reaction of an iron source with graphene. The nanocomposites were characterized by transmission electron microscopy, atomic force microscopy, X-ray diffraction, superconducting quantum interference, Raman spectroscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. This nanomaterial has been used as a magnetic solid-phase extraction sorbent to extract trace brominated flame retardants from environmental waters. Various extraction parameters were optimized including dosage and reusability of the nanocomposites, and pH of sample matrix. The reliability of the magnetic solid-phase extraction protocol based on graphene-doped Fe3O4 nanocomposites was evaluated by investigating the recoveries of 2,4,6-tribromophenol, tetrabromobisphenol A, 4-bromodiphenyl ether, and 4,4'-dibromodiphenyl ether in water samples. Good recoveries (85.0-105.0%) were achieved with the relative standard deviation ranging from 1.1-7.1%. Moreover, it is speculated from characterization and magnetic solid-phase extraction experiment that there is not only π-π stacking but also possible hydrophobic interaction between the graphene-doped Fe3O4 nanocomposites and analytes. PMID:25820830

  15. Tris(pentafluoroethyl)trifluorophosphate-basd ionic liquids as advantageous solid-phase micro-extraction coatings for the extraction of organophosphate esters in environmental waters.

    PubMed

    Shi, Fengqiong; Liu, Jingfu; Liang, Kang; Liu, Rui

    2016-05-20

    Ionic liquids (ILs) containing the tris(pentafluoroethyl)trifluorophosphate [FAP] anion and various cations have great potential in sample preparation because of their excellent hydrophobicity, thermostability and low hydrolysity. In the present study, a [FAP]-based IL, 1-hexyl-3-methylimidazolium tris (pentafluoroethyl) trifluoro phosphate ([HMIM][FAP]), was used as coatings of solid-phase microextraction (SPME) for extracting organophosphate esters (OPEs) from environmental water samples. This SPME fiber was fabricated by coating a stainless steel wire substrate with [HMIM][FAP] via a simple direct dip-coating approach, and the extraction was conducted by the direct immersion solid phase microextraction. Coupling to gas chromatography mass spectrometry (GC-MS), the developed SPME method exhibited excellent selectivity and sensitivity towards the extraction of 11 OPEs from aqueous samples. Satisfactory linearity (R(2)≥0.99) of the calibration curves was obtained over the range of 0.05-50.0ngmL(-1) with the limits of detection (LODs, S/N=3) and limits of quantification (LOQs, S/N=10) ranged from 0.13-7.40ngL(-1) and 0.50-24.0ngL(-1), respectively. The proposed SPME method showed excellent extraction efficiency to OPEs with enrichment factors in the range of 168-2603, and acceptable reproducibility with relative standard deviations (RSDs) ≤15% for single fiber (n=7) and ≤16% for fiber-to-fiber (n=3×3) at a concentration level of 0.5ngmL(-1), respectively. The prepared IL-based fiber was successfully applied to determine eleven common used OPEs in tap water, influent and effluent of sewage treatment plant, with results are comparable to those determined by the reference (UPLC-MS/MS), and spiked recoveries in the range of 84.0-108%, 82.1-123% and 82.8-100%, respectively. PMID:27086567

  16. Submicrometric Magnetic Nanoporous Carbons Derived from Metal-Organic Frameworks Enabling Automated Electromagnet-Assisted Online Solid-Phase Extraction.

    PubMed

    Frizzarin, Rejane M; Palomino Cabello, Carlos; Bauzà, Maria Del Mar; Portugal, Lindomar A; Maya, Fernando; Cerdà, Víctor; Estela, José M; Turnes Palomino, Gemma

    2016-07-19

    We present the first application of submicrometric magnetic nanoporous carbons (μMNPCs) as sorbents for automated solid-phase extraction (SPE). Small zeolitic imidazolate framework-67 crystals are obtained at room temperature and directly carbonized under an inert atmosphere to obtain submicrometric nanoporous carbons containing magnetic cobalt nanoparticles. The μMNPCs have a high contact area, high stability, and their preparation is simple and cost-effective. The prepared μMNPCs are exploited as sorbents in a microcolumn format in a sequential injection analysis (SIA) system with online spectrophotometric detection, which includes a specially designed three-dimensional (3D)-printed holder containing an automatically actuated electromagnet. The combined action of permanent magnets and an automatically actuated electromagnet enabled the movement of the solid bed of particles inside the microcolumn, preventing their aggregation, increasing the versatility of the system, and increasing the preconcentration efficiency. The method was optimized using a full factorial design and Doehlert Matrix. The developed system was applied to the determination of anionic surfactants, exploiting the retention of the ion-pairs formed with Methylene Blue on the μMNPC. Using sodium dodecyl sulfate as a model analyte, quantification was linear from 50 to 1000 μg L(-1), and the detection limit was equal to 17.5 μg L(-1), the coefficient of variation (n = 8; 100 μg L(-1)) was 2.7%, and the analysis throughput was 13 h(-1). The developed approach was applied to the determination of anionic surfactants in water samples (natural water, groundwater, and wastewater), yielding recoveries of 93% to 110% (95% confidence level). PMID:27336802

  17. Core-Shell Diamond as a Support for Solid-Phase Extraction and High-Performance Liquid Chromatography

    SciTech Connect

    Saini, Gaurav; Jensen, David S.; Wiest, Landon A.; Vail, Michael A.; Dadson, Andrew; Lee, Milton L.; Shutthanandan, V.; Linford, Matthew R.

    2010-06-01

    We report the formation of core-shell diamond particles for solid phase extraction (SPE) and high performance liquid chromatography (HPLC) made by layer-by-layer (LbL) deposition. Their synthesis begins with the amine functionalization of microdiamond by its immersion in an aqueous solution of a primary amine-containing polymer (polyallylamine (PAAm)). The amine-terminated microdiamond is then immersed in an aqueous suspension of nanodiamond, which leads to adsorption of the nanodiamond. Alternating (self-limiting) immersions in the solutions of the amine-containing polymer and the suspension of nanodiamond are continued until the desired number of nanodiamond layers is formed around the microdiamond. Finally, the core-shell particles are cross-linked with 1,2,5,6-diepoxycyclooctane or reacted with 1,2-epoxyoctadecane. Layer-by-layer deposition of PAAm and nanodiamond is also studied on planar Si/SiO2 surfaces, which were characterized by SEM, Rutherford backscattering spectrometry (RBS) and nuclear reaction analysis (NRA). Core-shell particles are characterized by diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), environmental scanning electron microscopy (ESEM), and Brunauer Emmett Teller (BET) surface area and pore s