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Sample records for solid-phase extraction adsorbent

  1. Metal-organic framework derived magnetic nanoporous carbon: novel adsorbent for magnetic solid-phase extraction.

    Science.gov (United States)

    Hao, Lin; Wang, Chun; Wu, Qiuhua; Li, Zhi; Zang, Xiaohuan; Wang, Zhi

    2014-12-16

    The fabrication of a magnetic nanoporous carbon (MNPC) via one-step direct carbonization of Co-based metal-organic framework has been achieved without using any additional carbon precursors. The morphology, structure, and magnetic behavior of the as-prepared Co-MNPC were characterized by using the techniques of scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, Raman spectroscopy, N2 adsorption, and vibrating sample magnetometer. The Co-MNPC has a high specific surface area, large pore volume, and super paramagnetism. Its performance was evaluated by the magnetic solid-phase extraction of some neonicotinoid insecticides from water and fatmelon samples followed by high-performance liquid chromatographic analysis. The effects of the main experimental parameters that could affect the extraction efficiencies were investigated. The results demonstrated that the Co-MNPC had an excellent adsorption capability for the compounds. PMID:25412429

  2. Porous lead(II)-based metal organic nanotubes as an adsorbent for dispersive solid-phase extraction of polybrominated diphenyl ethers from environmental water samples.

    Science.gov (United States)

    She, Xiao-Kun; Wang, Xia; Zhou, Jia-Bin; Zhao, Ru-Song

    2015-12-01

    Porous lead(II)-based metal-organic nanotubes (Pb-MONTs) were, for the first time, used as an adsorbent for dispersive solid-phase extraction (d-SPE) of polybrominated diphenyl ethers (PBDEs) at trace levels from environmental water samples. Gas chromatography-negative chemical ionization-mass spectrometry (GC-NCI-MS) was applied for sample detection. Box-Behnken design was performed to investigate and optimize the d-SPE parameters through a response surface methodology. The optimized conditions were obtained as listed: extraction time of 1min, 51.4mg of adsorbent and NaCl concentration of 7.42%. Under the optimized conditions, the new d-SPE-GC-NCI-MS method achieved wide range of linearity (2-1000ngL(-1)), low limits of detection (0.08-0.22ngL(-1)), satisfactory repeatability (0.79-8.62%, n=6) and satisfactory reproducibility (3.18-11.0%, n=5), and the possible extraction mechanism was also discussed. The proposed method was used in the analysis of real environmental water samples, and satisfactory recoveries were obtained in the range of 80.5-119.2%. These results indicated that Pb-MONTs have great potential as an adsorbent for the d-SPE of PBDEs at trace levels from environmental water samples. PMID:26559618

  3. Schiff base-chitosan grafted multiwalled carbon nanotubes as a novel solid-phase extraction adsorbent for determination of heavy metal by ICP-MS

    International Nuclear Information System (INIS)

    Highlights: ? Schiff base-chitosan grafted MWCNTs were synthesized via covalent modification. ? The S-CS-MWCNTs were successfully characterized by FT-IR, TEM and TGA. ? The S-CS-MWCNTs were used for solid-phase extraction of metal ions. ? A method was developed detection of metal ions from samples coupled with ICP-MS. - Abstract: A novel Schiff base-chitosan-grafted multiwalled carbon nanotubes (S-CS-MWCNTs) solid-phase extraction adsorbent was synthesized by covalently grafting a Schiff base-chitosan (S-CS) onto the surfaces of oxidized MWCNTs. The adsorbent was characterized by Fourier-transform infrared spectroscopy, transmission electron microscopy, and thermal gravimetric analysis. The results showed that S-CS was successfully grafted onto the surfaces of MWCNTs. A method was developed for the determination of heavy metals, namely V(V), Cr(VI), Cu(II), As(V) and Pb(II) in biological and environmental samples by inductively coupled plasma mass spectrometry coupled with preconcentration with S-CS-MWCNTs. The parameters influencing preconcentration of target ions, such as the pH of the sample solution, the flow rate of sample loading, the eluent concentration, and eluent volume, were investigated and optimized. Under the optimal conditions, the enrichment factors of V(V), Cr(VI), Cu(II), As(V), and Pb(II) reached 111, 95, 60, 52, and 128, respectively, and the detection limits were as low as 1.3–3.8 ng L?1. The developed method was successfully applied to the determination of trace-metal ions in herring, spinach, river water, and tap water with good recoveries ranging from 91.0% to 105.0%.

  4. Schiff base-chitosan grafted multiwalled carbon nanotubes as a novel solid-phase extraction adsorbent for determination of heavy metal by ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Bingye; Cao, Meirong; Fang, Guozhen; Liu, Bing; Dong, Xv; Pan, Mingfei [Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Tianjin 300457 (China); Wang, Shuo, E-mail: elisasw2002@yahoo.com.cn [Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Tianjin 300457 (China)

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer Schiff base-chitosan grafted MWCNTs were synthesized via covalent modification. Black-Right-Pointing-Pointer The S-CS-MWCNTs were successfully characterized by FT-IR, TEM and TGA. Black-Right-Pointing-Pointer The S-CS-MWCNTs were used for solid-phase extraction of metal ions. Black-Right-Pointing-Pointer A method was developed detection of metal ions from samples coupled with ICP-MS. - Abstract: A novel Schiff base-chitosan-grafted multiwalled carbon nanotubes (S-CS-MWCNTs) solid-phase extraction adsorbent was synthesized by covalently grafting a Schiff base-chitosan (S-CS) onto the surfaces of oxidized MWCNTs. The adsorbent was characterized by Fourier-transform infrared spectroscopy, transmission electron microscopy, and thermal gravimetric analysis. The results showed that S-CS was successfully grafted onto the surfaces of MWCNTs. A method was developed for the determination of heavy metals, namely V(V), Cr(VI), Cu(II), As(V) and Pb(II) in biological and environmental samples by inductively coupled plasma mass spectrometry coupled with preconcentration with S-CS-MWCNTs. The parameters influencing preconcentration of target ions, such as the pH of the sample solution, the flow rate of sample loading, the eluent concentration, and eluent volume, were investigated and optimized. Under the optimal conditions, the enrichment factors of V(V), Cr(VI), Cu(II), As(V), and Pb(II) reached 111, 95, 60, 52, and 128, respectively, and the detection limits were as low as 1.3-3.8 ng L{sup -1}. The developed method was successfully applied to the determination of trace-metal ions in herring, spinach, river water, and tap water with good recoveries ranging from 91.0% to 105.0%.

  5. Spectrophotometric determination of basic fuchsin from various water samples after vortex assisted solid phase extraction using reduced graphene oxide as an adsorbent.

    Science.gov (United States)

    Tokal?o?lu, ?erife; Yavuz, Emre; Aslanta?, Ay?e; ?ahan, Halil; Ta?k?n, Ferhat; Patat, ?aban

    2015-10-01

    In this study, a fast and simple vortex assisted solid phase extraction method was developed for the separation/preconcentration of basic fuchsin in various water samples. The determination of basic fuchsin was carried out at a wavelength of 554 nm by spectrophotometry. Reduced graphene oxide which was used as a solid phase extractor was synthesized and characterized by X-ray diffraction, scanning electron microscopy and the Brunauer, Emmett and Teller. The optimum conditions are as follows: pH 2, contact times for adsorption and elution of 30 s and 90 s, respectively, 10 mg adsorbent, and eluent (ethanol) volume of 1 mL. The effects of some interfering ions and dyes were investigated. The method was linear in the concentration range of 50-250 ?g L(-1). The adsorption capacity was 34.1 mg g(-1). The preconcentration factor, limit of detection and precision (RSD, %) of the method were found to be 400, 0.07 ?g L(-1) and 1.2%, respectively. The described method was validated by analyzing basic fuchsin spiked certified reference material (SPS-WW1 Batch 114-Wastewater) and spiked real water samples. PMID:25974670

  6. Glyoxal-Urea-Formaldehyde Molecularly Imprinted Resin as Pipette Tip Solid-Phase Extraction Adsorbent for Selective Screening of Organochlorine Pesticides in Spinach.

    Science.gov (United States)

    Yang, Chen; Lv, Tianwei; Yan, Hongyuan; Wu, Gaochan; Li, Haonan

    2015-11-01

    A new kind of glyoxal-urea-formaldehyde molecularly imprinted resin (GUF-MIR) was synthesized by a glyoxal-urea-formaldehyde (GUF) gel imprinting method with 4,4'-dichlorobenzhydrol as a dummy template. The obtained GUF-MIR was characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) and applied as a selective adsorbent of miniaturized pipet tip solid-phase extraction (PT-SPE) for the separation and extraction of three organochlorine pesticides (dicofol (DCF), dichlorodiphenyl dichloroethane (DDD), and tetradifon) in spinach samples. The proposed pretreatment procedures of spinach samples involved only 5.0 mg of GUF-MIR, 0.7 mL of MeOH-H2O (1:1, v/v) (washing solvent), and 0.6 mL of cyclohexane-ethyl acetate (9:1, v/v) (elution solvent). In comparison with other adsorbents (such as silica gel, C18, NH2-silica gel, and neutral alumina (Al2O3-N)), GUF-MIR showed higher adsorption and purification capacity for DCF, DDD, and tetradifon in aqueous solution. The average recoveries at three spiked levels ranged from 89.1% to 101.9% with relative standard deviations (RSDs) ? 7.1% (n = 3). The presented GUF-MIR-PT-SPE method combines the advantages of molecularly imprinted polymers (MIPs), GUF, and PT-SPE and can be used in polar solutions with high affinity and selectivity to the analytes in complex samples. PMID:26449689

  7. Use of ZIF-8-derived nanoporous carbon as the adsorbent for the solid phase extraction of carbamate pesticides prior to high-performance liquid chromatographic analysis.

    Science.gov (United States)

    Hao, Lin; Liu, Xingli; Wang, Juntao; Wang, Chun; Wu, Qiuhua; Wang, Zhi

    2015-09-01

    In this work, a chemically and thermally robust and highly porous zeolite-type metal-organic framework, zeolitic imidazolate framework-8 (ZIF-8), was used as both a precursor and a template and furfuryl alcohol as a second precursor to synthesize a nanoporous carbon. The prepared ZIF-8-derived nanoporous carbon was used as the solid-phase extraction adsorbent for the extraction of carbamate pesticides from cabbage and water samples. The adsorbed analytes were eluted with acetonitrile for the determination by high performance liquid chromatography-ultraviolet detection. The high surface area, high porosity, good stability and fast adsorption/desorption kinetics of the material enabled it to have a high adsorption capacity and good adsorption performance. Under optimum conditions, good linearity for the analytes in the range of 0.5-100 ng g(-1) and 0.05-20 ng mL(-1) existed for cabbage and water samples with the correlation coefficients of 0.9968-0.9980 and 0.9990-0.9995, respectively. The limits of detection (S/N=3) for the analytes were in the range of 0.25-0.1 ng g(-1) and 0.01-0.02 ng mL(-1) for the cabbage and water samples, respectively. The relative standard deviations (RSDs) for intra-day and the inter-day determinations of the analytes were below 7.0% and 12.5%, respectively. PMID:26003698

  8. A novel dispersive solid-phase extraction method using metal-organic framework MIL-101 as the adsorbent for the analysis of benzophenones in toner.

    Science.gov (United States)

    Li, Ning; Zhu, Quanfei; Yang, Yang; Huang, Jianlin; Dang, Xueping; Chen, Huaixia

    2015-01-01

    Metal-organic frameworks (MOFs) have been paid widespread attention in the field of adsorption and separation materials due to its porosity, large specific surface area, unsaturated metal-ligand sites and structural diversity. In this study, the green powder MIL-101 was synthesized and used for the extraction of benzophenone, 2,4-dihydroxybenzophenone and 2-hydroxy-4-methoxy-benzophenone from toner samples for the first time. The synthesized MIL-101 was characterized by X-ray diffraction, scanning electron microscopy, thermogravimetry and nitrogen adsorption porosimetry. The MIL-101 was applied as the dispersive solid phase extraction (DSPE) adsorbent for the extraction and preconcentration of benzophenone, 2,4-dihydroxybenzophenone and 2-hydroxy-4-methoxy-benzophenone from toner samples. The extraction conditions were investigated. Under the optimized conditions, a DSPE-HPLC method for the determination of benzophenone, 2,4-dihydroxybenzophenone and 2-hydroxy-4-methoxy-benzophenone was developed. The method yielded a linear calibration curve in the concentration ranges from 4.0 to 3500 ?g L(-1) for the three analytes in toner samples with regression coefficients (r(2)) of 0.9992, 0.9999 and 0.9990, respectively. Limits of detection were 1.2, 1.2 and 0.9 ?g L(-1), respectively. Both the intra-day and inter-day precisions (RSDs) were <10%. PMID:25476369

  9. Solid phase extraction of chromium(VI) from aqueous solutions by adsorption of its diphenylcarbazide complex on a mixed bed adsorbent (acid activated montmorillonite-silica gel) column

    Science.gov (United States)

    Rajesh, N.; Mishra, Braja Gopal; Pareek, Pawan Kumar

    2008-02-01

    A novel approach has been developed for the solid phase extraction of chromium(VI) based on the adsorption of its diphenylcarbazide complex on a mixture of acid activated montmorillonite (AAM)-silica gel column. The effect of various parameters such as acidity, stability of the column, sample volume, interfering ions, etc., were studied in detail. The adsorbed complex could be easily eluted using polyethylene glycol-sulfuric acid mixture and the concentration of chromium has been determined using visible spectrophotometry. The calibration graph was linear in the range 0-1 ?g mL -1 chromium(VI) with a detection limit of 6 ?g L -1. A highest preconcentration factor of 25 could be obtained for 250 mL sample volume using glass wool as support for the mixed bed adsorbent. Chromium(VI) could be effectively separated from other ions such as nickel, copper, zinc, chloride, sulfate, nitrate, etc., and the method has been successfully applied to study the recovery of chromium in electroplating waste water and spiked water samples.

  10. Graphene-modified TiO2 nanotube arrays as an adsorbent in micro-solid phase extraction for determination of carbamate pesticides in water samples.

    Science.gov (United States)

    Zhou, Qingxiang; Fang, Zhi

    2015-04-15

    Graphene is a good adsorbent for organic pollutants, especially for compounds containing benzene rings. When used in TiO2 nanotube arrays for micro-solid phase extraction (?-SPE), the combination of graphene's strong adsorptive properties with its good separation capabilities results in excellent sample preconcentration performance. In the present study, graphene-modified TiO2 nanotube arrays were prepared by electrodeposition using a cyclic voltammetric reduction method. Four carbamate pesticides, including metolcarb, carbaryl, isoprocarb, and diethofencarb, were used as model analytes to validate the enrichment properties of the prepared adsorbent in ?-SPE. Factors affecting the enrichment efficiency of the ?-SPE procedure were optimized and included sample pH, elution solvents, salting-out effect, adsorption time and desorption time. Under optimal conditions, graphene-modified TiO2 nanotube arrays exhibited excellent enrichment efficiency for carbamate pesticides. The detection limits of these carbamate pesticides ranged from 2.27 to 3.26 ?g L(-1). The proposed method was validated using four environmental water samples, and yields of pesticides recovered from spiked test samples of the four analytes were in the range of 83.9-108.8%. These results indicate that graphene-modified TiO2 nanotube arrays exhibit good adsorption to the target pollutants, and the method described in this work could be used as a faster and easier alternative procedure for routine analysis of carbamate pesticides in real water samples. PMID:25818138

  11. One pot synthesis of magnetic graphene/carbon nanotube composites as magnetic dispersive solid-phase extraction adsorbent for rapid determination of oxytetracycline in sewage water.

    Science.gov (United States)

    Sun, Yunyun; Tian, Jing; Wang, Lu; Yan, Hongyuan; Qiao, Fengxia; Qiao, Xiaoqiang

    2015-11-27

    A simple and time-saving one pot synthesis of magnetic graphene/carbon nanotube composites (M-G/CNTs) was developed that could avoid the tedious drying process of graphite oxide, and G/CNTs were modified by Fe3O4 nanoparticles in the reduction procedure. It contributed to a shorten duration of the synthesis process of M-G/CNTs. The obtained M-G/CNTs were characterized and the results indicated that CNTs and Fe3O4 nanoparticles were served as spacer distributing to the layers of graphene, which was beneficial for enlarging surface area and improving extraction efficiency. Moreover, M-G/CNTs showed good magnetic property and outstanding thermal stability. Then M-G/CNTs were applied as adsorbent of magnetic dispersive solid-phase extraction for rapid extraction and determination of oxytetracycline in sewage water. Under the optimum conditions, good linearity was obtained in the range of 20-800ngmL(-1) and the recoveries were ranged from 95.5% to 112.5% with relative standard deviations less than 5.8%. PMID:26518491

  12. Determination of polymeric aluminum in soil extracted with a modified anion-exchange resin as a solid-phase adsorbent by ICP-AES.

    Science.gov (United States)

    Luo, Mingbiao; Bi, Shuping; Wang, Chenyi; Huang, Junzhong

    2004-01-01

    In the present work, a new method was established by applying solid-phase extraction (SPE) to preconcentrate and separate polymeric aluminum (Al) and using ICP-AES to determine the polymeric Al, the total monomeric Al, and the total Al in soil extracts, respectively. A modified resin was prepared with impregnated 8-hydroxyquinoline-5-sulfoxinate (HQS) on the anion-exchange resin. It has good recognition ability for Al fractions, compared to the commonly used cation ion-exchange resin, which has a better ability to adsorb cations and a weak ability to recognize detailed Al species. The optimum conditions for Al fractionation sorption, elution and separation and the interference of foreign ions were studied with the prepared resin by continuous column and batch procedures. Monomeric Al was bound to Pyrocathecol Violet (PCV) at pH 6.2, whereas the polymeric Al species did not react with PCV for at least 15 min. Because a stable complex of Al-PCV was not absorbed on the HQS modified resin, the polymeric Al could be preconcentrated on-line by the HQS-modified resin. The adsorbed polymeric Al was eluted with 3 mL of 3 mol L(-1) of HCl, and then detected by ICP-AES. The method has been applied to directly determine polymeric Al in soil extracts with high selectivity as well as a high preconcentration factor. It gives a limit of detection of 0.6 ng mL(-1) with a relative standard deviation of less than 5.7% (n = 5, 0.24 microg mL(-1) Al). PMID:14753264

  13. Humic acids as both matrix for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and adsorbent for magnetic solid phase extraction.

    Science.gov (United States)

    Zhao, Qin; Xu, Jing; Yin, Jia; Feng, Yu-Qi

    2015-08-19

    In the present study, humic acids (HAs) were applied as both a matrix for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and an adsorbent of magnetic solid phase extraction (MSPE) for the first time. As natural macromolecule compounds, HAs are inherently highly functionalized and contain laser energy absorbing-transferring aromatic structures. This special molecular structure made HAs a good candidate for use as a MALDI matrix in small molecule analysis. At the same time, due to its good adsorption ability, HAs was prepared as MSPE adsorbent via a simple co-mixing method, in which the commercially available HAs were directly mixed with Fe3O4 magnetic nanoparticles (MNPs) in a mortar and grinded evenly and completely. In this process, MNPs were physically wrapped and adhered to tiny HAs leading to the formation of magnetic HAs (MHAs). To verify the bi-function of the MHAs, Rhodamine B (RdB) was chosen as model compound. Our results show that the combination of MHAs-based MSPE and MALDI-TOF-MS can provide a rapid and sensitive method for the determination of RdB in chili oil. The whole analytical procedure could be completed within 30 min for simultaneous determination of more than 20 samples, and the limit of quantitation for RdB was found to be 0.02 ?g/g. The recoveries in chili oil were in the range 73.8-81.5% with the RSDs less than 21.3% (intraday) and 20.3% (interday). The proposed strategy has potential applications for high-throughput analysis of small molecules in complex samples. PMID:26343436

  14. Using Zn/Al layered double hydroxide as a novel solid-phase extraction adsorbent to extract polycyclic aromatic hydrocarbons at trace levels in water samples prior to the determination of gas chromatography-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yan-Long [Wuhan University of Technology, School of Resources and Environmental Engineering, Wuhan (China); Shandong Academy of Sciences, Key Laboratory for Applied Technology of Sophisticated Analytical Instruments of Shandong Province, Analysis and Test Center, Jinan (China); Zhou, Jia-Bin [Wuhan University of Technology, School of Resources and Environmental Engineering, Wuhan (China); Zhao, Ru-Song; Chen, Xiang-Feng [Shandong Academy of Sciences, Key Laboratory for Applied Technology of Sophisticated Analytical Instruments of Shandong Province, Analysis and Test Center, Jinan (China)

    2012-09-15

    This paper demonstrates, for the first time, the great potential of using Zn/Al layered double hydroxide intercalated sodium dodecyl benzene sulfonate (Zn/Al-SDBS-LDH) as a solid-phase extraction (SPE) material in the extraction of persistent organic pollutants prior to the determination of gas chromatography-mass spectrometry in environmental water samples. Zn/Al-SDBS-LDH, a relatively inexpensive and simply prepared material, was synthesized and used as a SPE adsorbent to quantitatively determine the concentration of five polycyclic aromatic hydrocarbons (PAHs) in environmental water samples. Factors affecting extraction efficiency, such as, eluent type, eluent volume, flow rate of sample, sample volume, and amount of adsorbent, were investigated and optimized in detail. Experimental results indicate that there is an excellent linear relationship between peak area and the concentration of PAHs over the range of 5-500 ng L{sup -1}, and the precisions (relative standard deviation (RSD)) were 2.5-6.3 % under the optimum conditions. Based on the ratio of chromatographic signal-to-base line noise (S/N = 3), the limits of detection could reach 1.2-3.2 ng L{sup -1}. This novel method was successfully applied to the analysis of PAHs in environmental water samples. As such, we show here that the use of Zn/Al-SDBS-LDH as SPE adsorbent materials, coupled with gas chromatography-mass spectrometry, is an excellent improvement in the routine analysis of PAHs at trace levels in the environment. (orig.)

  15. Allantoin as a solid phase adsorbent for removing endotoxins.

    Science.gov (United States)

    Vagenende, Vincent; Ching, Tim-Jang; Chua, Rui-Jing; Gagnon, Pete

    2013-10-01

    In this study we present a simple and robust method for removing endotoxins from protein solutions by using crystals of the small-molecule compound 2,5-dioxo-4-imidazolidinyl urea (allantoin) as a solid phase adsorbent. Allantoin crystalline powder is added to a protein solution at supersaturated concentrations, endotoxins bind and undissolved allantoin crystals with bound endotoxins are removed by filtration or centrifugation. This method removes an average of 99.98% endotoxin for 20 test proteins. The average protein recovery is ?80%. Endotoxin binding is largely independent of pH, conductivity, reducing agent and various organic solvents. This is consistent with a hydrogen-bond based binding mechanism. Allantoin does not affect protein activity and stability, and the use of allantoin as a solid phase adsorbent provides better endotoxin removal than anion exchange, polymixin affinity and biological affinity methods for endotoxin clearance. PMID:24001944

  16. Magnetic solid-phase extraction using poly(para-phenylenediamine) modified with magnetic nanoparticles as adsorbent for analysis of monocyclic aromatic amines in water and urine samples.

    Science.gov (United States)

    Amiri, Amirhassan; Baghayeri, Mehdi; Nori, Somayeh

    2015-10-01

    In the present work, a simple and effective method based on magnetic separation has been developed for the extraction of monocyclic aromatic amines in water and urine samples using poly(para-phenylenediamine) modified with Fe3O4 nanoparticles (PpPD/Fe3O4) as an adsorbent. The chemical structures of the sorbent were characterized by field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectrophotometer (FT-IR). Various parameters affecting on the extraction efficiency of desired analytes, such as pH of solution, desorption conditions, extraction time, salt effect and amount of adsorbent have been investigated and optimized. The obtained optimal conditions were: sample pH, 6; amount of sorbent, 20mg; sorption time, 2min; elution solvent and its volume, dichloromethane and chloroform (3:1 v/v), 250?L; elution time, 30s and without addition of NaCl. Under the optimum conditions, detection limits in the range of 0.007-0.01ngmL(-1) were obtained by gas chromatography-flame ionization detector (GC-FID). The calibration curves were linear in the range 0.05-100ngmL(-1) with a correlation coefficient better than 0.9953. In addition, a satisfactory reproducibility was achieved by evaluating the intra- and inter-day precisions with relative standard deviations (RSDs) less than 5.9 and 7.3%, respectively. The proposed procedure has been successfully applied to the determination of target analytes in water and urine samples. The results demonstrated that the developed method is simple, inexpensive, accurate and remarkably free from interference effects. PMID:26341590

  17. Facile preparation of surface-exchangeable core@shell iron oxide@gold nanoparticles for magnetic solid-phase extraction: Use of gold shell as the intermediate platform for versatile adsorbents with varying self-assembled monolayers

    International Nuclear Information System (INIS)

    Graphical abstract: -- Highlights: •The core@shell Fe3O4@Au nanoparticles functionalized with SAMs were successfully constructed. •The SAMs could be transformed from one kind to another via thiol exchange process. •The developed nanomaterials could be applied in mode switching MSPE. -- Abstract: The core@shell Fe3O4@Au nanoparticles (NPs) functionalized with exchangeable self-assembled monolayers have been developed for mode switching magnetic solid-phase extraction (MSPE) using high performance liquid chromatography with ultraviolet detection. The adsorbents were synthesized by chemical coprecipitation to prepare magnetic cores followed by sonolysis to produce gold shells. Functionalization of Fe3O4@Au NPs surface was realized through self-assembly of commercially available low molecular weight thiol-containing ligands using gold shells as intermediate platform and the dynamic nature of Au–S chemistry allowed substituent of one thiol-containing ligand with another simply by thiol exchange process. The resultant adsorbents were characterized by transmission electronic microscopy, Fourier transform infrared spectroscopy, elemental analysis, contact angle measurement, and vibrating sample magnetometry. To evaluate the versatile performance of the developed MSPE adsorbents, they were applied for normal-phase SPE followed by reversed-phase SPE. A few kinds of diphenols and polycyclic aromatic hydrocarbons (PAHs) were employed as model analytes, respectively. The predominant parameters affecting extraction efficiency were investigated and optimized. Under the optimum experimental conditions, wide dynamic linear range (6.25–1600 ?g L?1 for diphenols and 1.56–100 ?g L?1 for PAHs) with good linearity (r2 ? 0.989) and low detection limits (0.34–16.67 ?g L?1 for diphenols and 0.26–0.52 ?g L?1 for PAHs) were achieved. The advantage of the developed method is that the Fe3O4@Au NPs could be reutilized for preconcentrating diverse target analytes in different SPE modes sequentially simply through treatment with desired thiol-containing ligands

  18. Application of bamboo charcoal as solid-phase extraction adsorbent for the determination of atrazine and simazine in environmental water samples by high-performance liquid chromatography-ultraviolet detector.

    Science.gov (United States)

    Zhao, Ru-Song; Yuan, Jin-Peng; Jiang, Ting; Shi, Jun-Bo; Cheng, Chuan-Ge

    2008-08-15

    In this article, a new method for the determination of triazine herbicides atrazine and simazine in environment aqueous samples was developed. It was based on solid-phase extraction (SPE) using bamboo charcoal as adsorbent and high-performance liquid chromatography-ultraviolet detector (HPLC-UV) for the enrichment and determination of atrazine and simazine at trace level. Related important factors influencing the extraction efficiency, such as the kind of eluent and its volume, flow rate of the sample, pH of the sample, and volume of the sample, were investigated and optimized in detail. Under the optimal conditions, the experimental results showed that excellent linearity was obtained over the range of 0.5-30 microg L(-1) with correlation coefficients 0.9991 and 0.9982, for atrazine and simazine, respectively; and the relative standard deviations of two analytes were 8.3, 8.7%, respectively. The proposed method was successfully applied to the analysis of tap water and well water samples. And satisfactory spiked recoveries were obtained in the range of 75.2-107.1%. The above results indicated that the developed method was an excellent alternative for the routine analysis in environmental field. PMID:18656684

  19. Nanosized spongelike Mn3O4 as an adsorbent for preconcentration by vortex assisted solid phase extraction of copper and lead in various food and herb samples.

    Science.gov (United States)

    Yavuz, Emre; Tokal?o?lu, ?erife; ?ahan, Halil; Patat, ?aban

    2016-03-01

    In this paper, a nanosized spongelike Mn3O4 was synthesized and used for the first time as an effective adsorbent for vortex-assisted separation and preconcentration of lead and copper from various food samples. Copper and lead were determined by flame atomic absorption spectrometry. The characterization of the nanosized spongelike Mn3O4 was performed by X-ray diffraction, scanning electron microscopy, Raman spectroscopy, Brunauer, Emmett and Teller surface area and zeta potential measurement. The contact times for both adsorption and elution were only 3min. Under the optimized conditions, detection limits for copper and lead were found to be 2.6?gL(-1) and 3.0?gL(-1), respectively. The relative standard deviations were found to be ?3.2%. The accuracy of the method was confirmed by analyzing the standard reference materials (BCR-482 Licken and SRM 1573a Tomato Leaves) and spiked real food and herb samples. PMID:26471580

  20. Determination of mercury by flow injection solid phase extraction coupled with on-line hydride generation ETAAS using as solid phase extractant a new functionalized mesoporous silica

    OpenAIRE

    López Guerrero, María del Mar; Siles Cordero, María Teresa; Vereda Alonso, Elisa Isabel; García de Torres, Amparo; Cano Pavón, José Manuel

    2013-01-01

    A chelating resin, [1,5 bis(di-2-pyridyl) methylene thiocarbohydrazide] bonded to mesoporous silica (DPTH-ms), has been used as a novel solid phase extractant. This resin has some advantages compared to most of other chelating adsorbents. Therefore, the aim is to develop a reliable method for determination of the aforementioned element from natural water samples by the on-line column preconcentration/HG-ETAAS using the resin DPTH-ms. With all experimental variables optimized, a linear cal...

  1. Extraction of Pb2+ using Silica from Rice Husks Ash (RHA – Chitosan as Solid Phase

    Directory of Open Access Journals (Sweden)

    Hanandayu Widwiastuti

    2013-03-01

    Full Text Available The existence of lead (Pb compounds in waters can be caused of waste pollution from industrial activities such as dye and battery industries. Lead has toxic characteristic and is able to causing deseases. The levels of Cr(VI can be decreased by methods such as electroplating, oxidation, reduction, and membrane separation. But this methods require high cost and produce a lot of waste. Furthermore, those methods cannot determine the small concentration of Pb2+. Therefore, solid phase extraction is used because it’s a simple method and can be used to preconcentrate Pb2+ ion. The aim of this study is to create solid phase from nature material as an alternative method to determine Pb2+ in water samples. The solid phase is silica from rice husks ash (RHA that was modified using chitosan. To achieve that aim, the optimization of silica : chitosan composition was done. The influence of Pb2+ concentration and citric acid concentration was studied to obtain optimum recovery of Pb2+. Interaction between Pb2+ ion and solid phase silica – chitosan could be estimated based on the result. The result showed the optimum composition of silica : chitosan is 65% silica : 35% chitosan with Cation Exchange Capacity (CEC 0.00455 mek/g. Mass Adsorbed Pb2+for 1 g silica : chitosan 65% is 9.715 mg/g. Optimum recovery of Pb2+ on solid phase extraction is reached at concentration of Pb2+ 10 ppm and citric acid concentration 0.05 M (88.25 % and 81.18 %. This result showed that solid phase extraction using silica – chitosan can be used as an alternative method to determine Pb2+ in water.

  2. Solid-phase group-specific adsorbants in assays for glycoproteins

    International Nuclear Information System (INIS)

    The focus of the paper is on several technical advances in the assays for glycoprotein hormones and enzymes that have been achieved by the use of the solid-phase cabohydrate-specific adsorbant concanavalin-A. Purification of glycoprotein radioligand after labelling by the Chloramine-T method is readily accomplished using a small column of agarose-bound concanavalin-A which separates glycoprotein radioligand from radioiodide and radiolabelled unadsorbed contaminants. After concanavalin-A column chromatography, radiolabelled glycoprotein hormone preparations exhibited improved binding to antibodies and tissue receptors. To increase the effective sensitivity of radioimmunoassays for glycoproteins, agarose-bound concanavalin-A is used to extract and concentrate the glycoproteins from various biological samples. For example, the effective sensitivity for the detection of human thyrotropin in serum was improved approximately 5-fold by using concanavalin-A concentrates of 1.5ml of serum. Partial purification of the glycoprotein dopamine-?-hydroxylase from serum using agarose-bound concanavalin-A resulted in separation of the serum factors that interfere with the measurement of enzyme activity. We conclude that in assays for glycoproteins, concanavalin-A is useful for purification of radioligand, for preparation of concentrates of glycoproteins from biological samples and for separation of glycoproteins from various interfering factors contained in biological samples before radioligand or radioenzyme assay. (author)

  3. Preparation of bioconjugates by solid-phase conjugation to ion exchange matrix-adsorbed carrier proteins

    DEFF Research Database (Denmark)

    Houen, G.; Olsen, D.T.; Hansen, P.R.; Petersen, K.B.; Barkholt, Vibeke

    2003-01-01

    A solid-phase conjugation method utilizing carrier protein bound to an ion exchange matrix was developed. Ovalbumin was adsorbed to an anion exchange matrix using a batch procedure, and the immobilized protein was then derivatized with iodoacetic acid N-hydroxysuccinimid ester. The activated protein was conjugated with glutathione, the conjugation ratio determined by acid hydrolysis, and amino acid analysis performed with quantification of carboxymethyl cysteine. Elution of conjugates from the r...

  4. Simultaneous solid phase extraction of cobalt, strontium and cesium from liquid radioactive waste using microcrystalline naphthalene

    International Nuclear Information System (INIS)

    Most of the procedures developed for the extraction of cobalt, strontium and cesium by solid phase extraction do not employ simultaneous extraction of them. In this study, rapid simultaneous removal of Co2+, Sr2+ and Cs+ on microcrystalline naphthalene as solid-phase extractant was investigated. These ions were allowed to form chelates with oxine and then adsorbed on freshly microcrystalline naphthalene from aqueous solutions. The solid phase extraction procedure (SPE) was optimized by using model solution containing Co2+, Sr2+ and Cs+ in batch system. The effects of different parameters such as variation in pH, reagent concentration, standing time, naphthalene solution concentration and contact time on the simultaneous removal of these ions was studied. The obtained results indicated that, sorption was found to be rapid, and the percentage removal of Co2+, Sr2+ and Cs+ was found to be 98, 79 and 68% within 10 min, respectively. The kinetics of the sorption process was investigated to understand the kinetic characteristics of sorption of metal chelates onto microcrystalline naphthalene. The developed procedure has been successfully applied to the removal and recovery of 60Co and 134Cs from liquid radioactive waste. The parameters can be used for designing a plant for treatment of wastewater economically.

  5. Multiwalled carbon nanotubes as a solid-phase extraction adsorbent for the determination of three barbiturates in pork by ion trap gas chromatography-tandem mass spectrometry (GC/MS/MS) following microwave assisted derivatization

    International Nuclear Information System (INIS)

    A new method was developed for the rapid screening and confirmation analysis of barbital, amobarbital and phenobarbital residues in pork by gas chromatography-tandem mass spectrometry (GC/MS/MS) with ion trap MSD. The residual barbiturates in pork were extracted by ultrasonic extraction, cleaned up on a multiwalled carbon nanotubes (MWCNTs) packed solid phase extraction (SPE) cartridge and applied acetone-ethyl acetate (3:7, v/v) mixture as eluting solvent and derivatized with CH3I under microwave irradiation. The methylated barbiturates were separated on a TR-5MS capillary column and detected with an ion trap mass detector. Electron impact ion source (EI) operating MS/MS mode was adopted for identification and external standard method was employed for quantification. One precursor ion m/z 169 was selected for analysis of barbital and amobarbital and m/z 232 was selected for phenobarbital. The product ions were obtained under 1.0 V excitation voltage. Good linearities (linear coefficient R > 0.99) were obtained at the range of 0.5-50 ?g kg-1. Limit of detection (LOD) of barbital was 0.2 ?g kg-1 and that of amobarbital and phenobarbital were both 0.1 ?g kg-1 (S/N ? 3). Limit of quatification (LOQ) was 0.5 ?g kg-1 for three barbiturates (S/N ? 10). Satisfying recoveries ranging from 75% to 96% of the three barbiturates spiked in pork were obtained, with relative standard deviations (R.S.D.) in the range of 2.1-7.8%

  6. Solid-phase extraction of perfluoroalkylated compounds from sea water.

    Science.gov (United States)

    Villaverde-de-Sáa, Eugenia; Fernández-López, María; Rodil, Rosario; Quintana, José Benito; Racamonde, Inés; Cela, Rafael

    2015-06-01

    This study describes an in-depth investigation of the parameters involved in the solid-phase extraction performance of perfluoroalkylated compounds (seven carboxylates and one sulfonate), particularly with sea water samples. The two most popular sorbents, Oasis WAX and Oasis HLB, were considered and it was observed that the high ionic strength of sea water may impair solid-phase extraction recoveries. In the final protocol, Oasis HLB cartridges were selected, incorporating a 10% methanol clean-up step before elution with methanol, since less matrix effects were obtained. The proposed method allows successful recoveries, higher than 71%, and relative standard deviations lower than 20%. It also provides excellent limits of detection values between 0.01 and 0.21 ng/L. Finally, the method was applied to fresh and sea water samples, where several perfluoroalkylated compounds were found at concentrations ranging between 0.16 and 64 ng/L. In the case of perfluorooctane sulfonate, recently included in the Water Frame Directive, its concentration reached the highest values among the perfluoroalkylated compounds measured (64 ng/L in river samples). PMID:25800377

  7. A molecularly imprinted polymer for solid phase extraction of allantoin

    International Nuclear Information System (INIS)

    We describe a molecularly imprinted polymer (MIP) for the solid-phase extraction of the skin protectant allantoin. The MIP was deposited on the surface of monodisperse silica microspheres possessing acroyl groups on the surface (MH-SiO2). The resulting MIP microspheres (MH-SiO2.MIP) showed a 3.4-fold higher adsorption capacity and a 1.9-fold better selectivity for allantoin than the respective non-imprinted polymer (MH-SiO2.NIP). The monolayer adsorption capacities of the MH-SiO2.MIP and the MH-SiO2.NIP were calculated with the help of the Langmuir model and found to be 6.8 and 1.9 mg•g?1, respectively. Adsorption kinetics fit a pseudo-second order rate mechanism, with an initial adsorption rate of 1.44 for the MH-SiO2.MIP, and of 0.07 mg•g?1•min?1 for the MH-SiO2.NIP. The material can be regenerated, and its adsorption capacity for allantoin remains stable for at least five regeneration cycles. It was successfully used as a sorbent for the selective solid-phase extraction of allantoin from Rhizoma dioscoreae. (author)

  8. Polythiophene-coated Fe3O4 nanoparticles as a selective adsorbent for magnetic solid-phase extraction of silver(I), gold(III), copper(II) and palladium(II)

    International Nuclear Information System (INIS)

    We have developed a fast method for sensitive extraction and determination of the metal ions silver(I), gold(III), copper(II) and palladium(II). Fe3O4 magnetic nanoparticles were modified with polythiophene and used for extraction the metal ions without a chelating agent. Following extraction, the ions were determined by flow injection inductively coupled plasma optical emission spectrometry. The influence of sample pH, type and volume of eluent, amount of adsorbent, sample volume and time of adsorption and desorption were optimized. Under the optimum conditions, the calibration plots are linear in the 0.75 to 100 ?g L?1 concentration range (R2?>?0.998), limits of detection in the range from 0.2 to 2.0 ?g L?1, and enhancement factors in the range from 70 to 129. Precisions, expressed as relative standard deviations, are lower than 4.2 %. The applicability of the method was demonstrated by the successful analysis of tap water, mineral water, and river water. (author)

  9. Selective solid-phase extraction of uranium by salicylideneimine-functionalized hydrothermal carbon

    International Nuclear Information System (INIS)

    Highlights: ? Hydrothermal carbon material as solid-phase extractant matrix. ? An excellent hexavalent cation ligand, salicylideneimine, is grafted on the matrix. ? Adsorbent shows high affinity and selectivity to U(VI) in simulated nuclear effluent. ? Process is fast, endothermic, spontaneous, and pseudo-second-order chemisorption. - Abstract: A new salicylideneimine-functionalized hydrothermal-carbon-based solid-phase extractant was developed for the purpose of separating uranium selectively for sustainability of uranium resources. The resulting adsorption material was obtained via hydrothermal carbonization, calcination at mild temperature (573.15 K), amination, and grafting with salicylaldehyde in sequence. Both Fourier transform infrared spectra and elemental analysis proved the successful grafting of salicylideneimine onto hydrothermal carbon matrix. Adsorption behaviors of the extractant on uranium(VI) were investigated by varying pH values of solution, adsorbent amounts, contact times, initial metal concentrations, temperatures, and ionic strengths. An optimum adsorption capacity of 1.10 mmol g?1 (261 mg g?1) for uranium(VI) was obtained at pH 4.3. The present adsorption process obeyed pseudo-second-order model and Langmuir isotherm. Thermodynamic parameters (?H = +8.81 kJ mol?1, ?S = +110 J K?1 mol?1, ?G = ?23.0 kJ mol?1) indicated the adsorption process was endothermic and spontaneous. Results from batch adsorption test in simulated nuclear industrial effluent, containing Cs+, Sr2+, Ba2+, Mn2+, Co2+, Ni2+, Zn2+, La3+, Ce3+, Nd3+, Sm3+, and Gd3+, showed the adsorbent could separate uranium(VI) from those competitive ions with high selectivity. The adsorbent might be promising for use in certain key steps in any future sustainable nuclear fuel cycle.

  10. Solid phase extraction of nitrate and nitrite anions using naturally and available sorbent

    International Nuclear Information System (INIS)

    Radioactive waste contains nitrate and nitrite as well as radioactive fission products. Nitrate and nitrite anions are two of the major components of nuclear waste streams and contribute to environmental release hazards. The removal of nitrate and nitrite is a necessary step for the further treatment low-level radioactive wastes. The focus of the research is to evaluate the adsorption potential of solid phase derived from rice straw for nitrate and nitrite anions in single- and binary-component systems due to the fact that the rice straw is a very abundant and by-product material. The removal was accomplished under the optimize conditions of temperature, concentration, pH, contact time and quantity of adsorbent as these parameters are some of the main factors influencing the uptake of two solutes at the solid-solution interface. Batch-mode kinetic and equilibrium studies have been carried out. The experimental data was analyzed using equilibrium isotherm and kinetic models. The thermodynamic parameters (?Gdeg, ?Hdeg, and ?Sdeg) were also determined using the equilibrium constant value obtained at different temperatures. Results show that this adsorbent is effective and much better or even superior than many sorbents for removal of nitrate and nitrite. The prepared sorbent as solid-phase extractant was successfully applied for the extraction of nitrate from actual water samples. (author)

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

    Science.gov (United States)

    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 ?g mL(-1), low limits of detection (0.0005-0.0019 ?g 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

  12. In-syringe dispersive solid phase extraction: a novel format for electrospun fiber based microextraction.

    Science.gov (United States)

    Zhu, Gang-Tian; He, Xiao-Mei; Cai, Bao-Dong; Wang, Han; Ding, Jun; Yuan, Bi-Feng; Feng, Yu-Qi

    2014-12-01

    A novel in-syringe dispersive solid phase extraction (dSPE) system using electrospun silica fibers as adsorbents has been developed in the current work. A few milligrams of electrospun silica fibers were incubated in sample solution in the barrel of a syringe for microextraction assisted by vortex. Due to the benefit of dispersion and the high mass transfer rate of the sub-microscale electrospun silica fibers, the extraction equilibrium was achieved in a very short time (less than 1 min). Moreover, thanks to the long fibrous properties of electrospun fibers, the separation of the adsorbent from sample solution was easily achieved by pushing out the sample solution which therefore simplified the sample pretreatment procedure. Besides, the analytical throughput was largely increased by using a multi-syringe plate to perform the extraction experiment. The performance of the in-syringe dSPE device was evaluated by extraction of endogenous cytokinins from plant tissue samples based on the hydrophilic interaction. Six endogenous cytokinins in 20 mg of Oryza sativa L. (O. sativa) leaves were successfully determined under optimized conditions using in-syringe dSPE combined with liquid chromatography-mass spectrometry analysis. The results demonstrated that the in-syringe dSPE method was a rapid and high-throughput strategy for the extraction of target compounds, which has great potential in microscale sample pretreatment using electrospun fibers. PMID:25317894

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. MOLECULARLY IMPRINTED SOLID PHASE EXTRACTION FOR TRACE ANALYSIS OF DIAZINON IN DRINKING WATER

    Directory of Open Access Journals (Sweden)

    M. Rahiminejad ? S. J. Shahtaheri ? M. R. Ganjali ? A. Rahimi Forushani ? F. Golbabaei

    2009-04-01

    Full Text Available Amongst organophosphate pesticides, the one most widely used and common environmental contaminant is diazinon; thus methods for its trace analysis in environmental samples must be developed. Use of diazinon imprinted polymers such as sorbents in solid phase extraction, is a prominent and novel application area of molecular imprinted polymers. For diazinon extraction, high performance liquid chromatography analysis was demonstrated in this study. During optimization of the molecular imprinted solid phase extraction procedure for efficient solid phase extraction of diazinon, Plackett-Burman design was conducted. Eight experimental factors with critical influence on molecular imprinted solid phase extraction performance were selected, and 12 different experimental runs based on Plackett-Burman design were carried out. The applicability of diazinon imprinted polymers as the sorbent in solid phase extraction, presented obtained good recoveries of diazinon from LC-grade water. An increase in pH caused an increase in the recovery on molecular imprinted solid phase extraction. From these results, the optimal molecular imprinted solid phase extraction procedure was as follows: solid phase extraction packing with 100 mg diazinon imprinted polymers; conditioning with 5 mL of methanol and 6 mL of LC-grade water; sample loading containing diazinon (pH=10; washing with 1 mL of LC-grade water, 1 mL LC- grade water containing 30% acetonitrile and 0.5 mL of acetonitrile, respectively; eluting with 1 mL of methanol containing 2% acetic acid. The percentage recoveries obtained by the optimized molecular imprinted solid phase extraction were more than 90% with drinking water spiked at different trace levels of diazinon. Generally speaking, the molecular imprinted solid phase extraction procedure and subsequent high performance liquid chromatography analysis can be a relatively fast and proper approach for qualitative and quantitative analysis of diazinon in drinking water.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. 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.

    Science.gov (United States)

    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

  18. On-line solid phase selective separation and preconcentration of Cd(II) by solid-phase extraction using carbon active modified with methyl thymol blue

    International Nuclear Information System (INIS)

    An on-line flow system was used to develop a selective and efficient on-line sorbent extraction preconcentration system for cadmium. The method is based on adsorption of cadmium ions onto the activated carbon modified with methyl thymol blue. Then the adsorbed ions were washed using 0.5 M HNO3 and the eluent was used to determine the Cd(II) ions using flame atomic absorption spectrometry. The results obtained show that the modified activated carbon has the greatest adsorption capacity of 80 ?g of Cd(II) per 1.0 g of the solid phase. The optimal pH value for the quantitative preconcentration was 9.0 and full desorption is achieved by using 0.5 M HNO3 solution. It is established that the solid phase can be used repeatedly without a considerable adsorption capacity loss. The detection limit was less than 1 ng mL-1 Cd(II), with an enrichment factor of 1000. The calibration graph was linear in the range of 1-2000 ng mL-1 Cd(II). The developed method has been applied to the determination of trace cadmium (II) in water samples and in the following reference materials: sewage sludge (CRM144R), and sea water (CASS.4) with satisfactory results. The accuracy was assessed through recovery experiments

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

    Science.gov (United States)

    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 ?g L-1 (R2 = 0.9991). The repeatability and reproducibility (RSD%) for 0.050 ?g 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 ?g 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.

  20. Different methods to select the best extraction system for solid-phase extraction.

    Science.gov (United States)

    Bielicka-Daszkiewicz, Katarzyna

    2015-02-01

    The optimization methods for planning a solid-phase extraction experiment are presented. These methods are based on a study of interactions between different parts of an extraction system. Determination of the type and strength of interaction depends on the physicochemical properties of the individual components of the system. The main parameters that determine the extraction properties are described in this work. The influence of sorbents' and solvents' polarity on extraction efficiency, Hansen solubility parameters and breakthrough volume determination on sorption and desorption extraction step are discussed. PMID:25421494

  1. ZnO nanorod array solid phase micro-extraction fiber coating: fabrication and extraction capability

    International Nuclear Information System (INIS)

    In this paper, a ZnO nanorod array has been introduced as a coating to the headspace solid phase micro-extraction (HSSPME) field. The coating shows good extraction capability for volatile organic compounds (VOCs) by use of BTEX as a standard and can be considered suitable for sampling trace and small molecular VOC targets. In comparison with the randomly oriented ZnO nanorod HSSPME coating, ZnO nanorod array HSSPME fiber coating shows better extraction capability, which is attributed to the nanorod array structure of the coating. Also, this novel nanorod array coating shows good extraction selectivity to 1-propanethiol.

  2. Recovery evaluation of organophosphorus pesticides from bee pollen by matrix solid-phase dispersion extraction using sorbents based on silica and titania

    International Nuclear Information System (INIS)

    This work focused on the evaluation of the recovery of organophosphorus pesticides from bee pollen after matrix solid phase-dispersion extraction (MSPD). Materials based on silica, titania and titania modified with polivylnylimidazole or polyestirene were used as adsorbents for the extraction of pesticides. Small amounts of fortified pollen (0.1 g, at 1 micro-g/g of pesticides), adsorbent (0.4 g) and solvent elution (1 mL de acetonitrile – ACN) were used in the extractions. For recovery evaluation, pollen extracts were analyzed by gas chromatography coupled with mass spectrometry.

  3. Low level determination of pesticides in environmental water samples using solid-phase extraction and high performance liquid chromatography

    International Nuclear Information System (INIS)

    A multi residue analytical method for pesticides in water that utilizes liquid sold extraction, commonly referred to as solid-phase extraction (SPE) with octadecyl bounded silica cartridges (C/sub 18/ BSc's) followed by reverse-phase high performance liquid chromatography (RP-HPLC) with UV-absorption detection was developed. Recoveries of most of pesticides were greater than 81% with C/sub 18/ cartridges from spiked water at 100 and 200 ppb levels. Low background in silica based adsorbent allows detection limits of 0.10-0.25 ppb levels. low background in silica based adsorbed allows detection limits of 0.10-0.25 ppb for the monitored pesticides. (author)

  4. Determination of melamine in aquaculture feed samples based on molecularly imprinted solid-phase extraction.

    Science.gov (United States)

    Lian, Ziru; Liang, Zhenlin; Wang, Jiangtao

    2015-10-01

    This research highlights the application of highly efficient molecularly imprinted solid-phase extraction for the preconcentration and analysis of melamine in aquaculture feed samples. Melamine-imprinted polymers were synthesized employing methacrylic acid and ethylene glycol dimethacrylate as functional monomer and cross-linker, respectively. The characteristics of obtained polymers were evaluated by scanning electron microscopy, Fourier transform infrared spectroscopy and binding experiments. The imprinted polymers showed an excellent adsorption ability for melamine and were applied as special solid-phase extraction sorbents for the selective cleanup of melamine. An off-line molecularly imprinted solid-phase extraction procedure was developed for the separation and enrichment of melamine from aquaculture feed samples prior to high-performance liquid chromatography analysis. Optimum molecularly imprinted solid-phase extraction conditions led to recoveries of the target in spiked feed samples in the range 84.6-96.6% and the relative standard deviation less than 3.38% (n = 3). The aquaculture feed sample was determined, and there was no melamine found. The results showed that the molecularly imprinted solid-phase extraction protocols permitted the sensitive, uncomplicated and inexpensive separation and pre-treatment of melamine in aquaculture feed samples. PMID:26304786

  5. Solid-phase extraction of berries’ anthocyanins and evaluation of their antioxidative properties.

    Czech Academy of Sciences Publication Activity Database

    Denev, P.; ?íž, Milan; Ambrožová, Gabriela; Lojek, Antonín; Yanakieva, I.; Kratchanova, M.

    2010-01-01

    Ro?. 123, ?. 4 (2010), s. 1055-1061. ISSN 0308-8146 R&D Projects: GA MŠk(CZ) OC08058 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : anthocyanins * solid-phase extraction * berry extracts Subject RIV: BO - Biophysics Impact factor: 3.458, year: 2010

  6. Optimisation of the membrane-assisted passive sampler and its comparison with solid phase extraction technique

    Scientific Electronic Library Online (English)

    Hlengilizwe, Nyoni; Luke, Chimuka; Branislav, Vrana; Ewa, Cukrowska; Hlanganani, Tutu.

    2010-07-01

    Full Text Available A novel membrane-assisted passive sampler was further optimised in the laboratory. It was then compared to the solid phase extraction technique in terms of the extraction efficiency, enrichment factor, detection limit and selectivity in wastewater. The passive sampler was exposed to 3 [...] /revistas/wsa/v36n4/a15exp01.gif"> wastewater samples under laboratory conditions for 3 days. Five hundred millilitres of wastewater was extracted with C18 cartridges. The extraction efficiency of the passive sampler ranged from 4 to 10% while in solid phase extraction it was 40 to 67% for the 3 chlorophenols. In both cases, extraction efficiency was highest for 2,4-dichlorophenol. The low extraction efficiency in the passive sampler supports the idea that it is not an exhaustive extraction technique and does not disturb the chemical equilibrium of the sample. It therefore measures the bioavailable fraction of the compound and can be used for equilibrium sampling and extraction. The obtained enrichment factors from the passive sampler were 89 and 295 for 2-chlorophenol and 2,4-dichlorophenol, respectively. From solid phase extraction, enrichment factors of 102, 113 and 167 were obtained for 2-chlorophenol, 4-chlorophenol and 2,4-dichlorophenol, respectively. The enrichment factor (~2.5) and sampling rates (~28 µ·h-1) were both low for 4-chlorophenol in wastewater from passive sampler extraction. The calculated sampling rates were found to be 2 604 µ·h-1 for 2-chlorophenol, 1 074 µ·h-1 for 4-chlorophenol and 5 089 µ·h-1 for 2,4-dichlorophenol in spiked deionised water. In wastewater, the sampling rates were found to be 1 544 µ·h-1 for 2-chlorophenol, 28 µ·h-1 for 4-chlorophenol and 5 106 µ·h-1 for 2,4-dichlorophenol. The passive sampler was found to be superior in its selectivity towards the target compounds compared to solid phase extraction technique with C18 sorbent. Chromatograms from solid phase extraction of wastewater contained high peaks of unidentified, potentially interfering compounds, especially in the early part of the chromatogram. In contrast, chromatograms from the passive sampler extraction were very clean. The detection limits of the passive sampler were comparable with that of solid phase extraction and were around 1.5 µg·-1 except for 4-chlorophenol that was high in wastewater (~100 µg·-1).

  7. Micro-solid-phase extraction coupled to desorption electrospray ionization-high-resolution mass spectrometry for the analysis of explosives in soil

    DEFF Research Database (Denmark)

    Bianchi, Federica; Gregori, Adolfo; Braun, Gabriele; Crescenzi, Carlo; Careri, Maria

    2015-01-01

    Home-made micro-solid-phase extraction (SPE) cartridges using different adsorbent materials were tested for the desorption electrospray ionization-high-resolution mass spectrometry (DESI-HRMS) determination of explosives like 2,4,6-trinitrotoluene, cyclotrimethylene-trinitramine, cyclotetramethylene-tetranitramine, pentaerythritol tetranitrate, and trinitrophenylmethylnitramine in soil samples. Quantitation limits in the low nanogram per kilogram range proved the reliability of the method for th...

  8. Micro versus macro solid phase extraction for monitoring water contaminants: a preliminary study using trihalomethanes.

    Science.gov (United States)

    Alexandrou, Lydon D; Spencer, Michelle J S; Morrison, Paul D; Meehan, Barry J; Jones, Oliver A H

    2015-04-15

    Solid phase extraction is one of the most commonly used pre-concentration and cleanup steps in environmental science. However, traditional methods need electrically powered pumps, can use large volumes of solvent (if multiple samples are run), and require several hours to filter a sample. Additionally, if the cartridge is open to the air volatile compounds may be lost and sample integrity compromised. In contrast, micro cartridge based solid phase extraction can be completed in less than 2 min by hand, uses only microlitres of solvent and provides comparable concentration factors to established methods. It is also an enclosed system so volatile components are not lost. The sample can also be eluted directly into a detector (e.g. a mass spectrometer) if required. However, the technology is new and has not been much used for environmental analysis. In this study we compare traditional (macro) and the new micro solid phase extraction for the analysis of four common volatile trihalomethanes (trichloromethane, bromodichloromethane, dibromochloromethane and tribromomethane). The results demonstrate that micro solid phase extraction is faster and cheaper than traditional methods with similar recovery rates for the target compounds. This method shows potential for further development in a range of applications. PMID:25625633

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

    Science.gov (United States)

    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...

  10. Role of Hansen solubility parameters in solid phase extraction.

    Science.gov (United States)

    Bielicka-Daszkiewicz, K; Voelkel, A; Pietrzy?ska, M; Héberger, K

    2010-08-27

    The sorbent-eluent systems combined from eight polymeric sorbents and seven solvents as eluents were used for the extraction of phenol and its oxidation products from water samples. The individual interactions between sorbents, eluents and analytes were characterized by Hansen solubility parameters. Principal components analysis (PCA) was used for revealing the dominant interactions (dispersive, polar, and hydrogen bonding type) in sorbent-analyte-eluent systems. The importance of solubility parameters was also determined by a novel procedure based on sum of ranking differences (SRD). Although PCA and ranking by SRD are based on different principles and calculations, they have provided very similar results. The recovery in a given system has been predicted from the magnitudes of mutual interactions (sorbent-analyte, sorbent-eluent, analyte-eluent) by multiple linear regression. PMID:20643412

  11. Solid phase extractive preconcentration of silver from aqueous samples.

    Science.gov (United States)

    Ayata, Sevda; Kaynak, Ipek; Merdivan, Melek

    2009-06-01

    N,N-dibutyl-N1-benzoylthiourea (DBBT) impregnated onto a polymeric matrix, Amberlite XAD-16 was prepared. The separation and enrichment of Ag(I) from solution was investigated. Effective extraction conditions were optimized in column methods prior to determination by atomic absorption spectrometry. The optimum pH range for quantitative adsorption is 2-5. Quantitative recovery of Ag was achieved by stripping with 1 mol L(-1) thiourea in 1 mol L(-1) HCl. The sorption capacity of resin is 0.115 mmol Ag+ g(-1) resin. The relative standard deviation and detection limit was 3.1% for 1 microg Ag+ mL(-1) solution and 0.11 microg L(-1), respectively. The method was used for the determination of silver in geological water samples. PMID:18509733

  12. Electrospun polymer nanofibres as solid-phase extraction sorbents for extraction and quantification of microcystins.

    Science.gov (United States)

    Wei, HaiYan; Yang, Fei; Wang, Yu; Zhou, YuanLong; Yan, Yan; Liang, GeYu; Yin, LiHong; Pu, YuePu

    2015-11-01

    Electrospun polymer nanofibres were used as novel solid-phase extraction (SPE) sorbents to extract and quantify the microcystins (MCs) including microcystin-RR (MC-RR) and microcystin-LR (MC-LR) from in-suit water samples. The parameters that influenced the extraction ef?ciency were studied, including the amount of nanofibre, eluted solvent, eluted volume, pH, and the water sample volume. Under optimized conditions, a linear response for MC-RR and MC-LR over the range of 0.25-4?µg/L was achieved with r(2) values of 0.998 and 0.997, respectively. The extraction recovery of MC-RR and MC-LR was 97-102% and 98-100%, respectively, when the MC concentration was 0.25-4?µg/L. When their concentrations ranged from 0.05? to 0.25?µg/L, the MCs could be detected with high accuracy by the nanofibre SPE sorbent combined with nitrogen gas. Due to its simplicity, environment-friendliness, high efficiency, reusability, and sensitivity, the electrospun polymer nanofibre can be applied as a novel SPE sorbent to extract and detect the MCs from in-suit water samples. PMID:25978348

  13. Solid-phase extraction of antioxidant compounds from commercial cranberry extract and its antiradical activity

    Directory of Open Access Journals (Sweden)

    Tumbas Vesna T.

    2007-01-01

    Full Text Available This study is concerned with the fractionation and determination of major antioxidant compounds (phenols, flavonoids, anthocyanins and vitamin C in commercial cranberry extract. The total content of phenolics, flavonoids and total and monomers of anthocyanins, determined spectrophotometrically, was 1.67 mg/g, 0.41 mg/g, 5.12 mg/g and 3.32 mg/g. The content of vitamin C, determined volumetrically, was 121.74 mg/g. Commercial cranberry extract was dissolved in 80 % acetone and the solution was fractionated using solid phase extraction (SPE in order to abstract vitamin C, neutral and acidic phenols. The free radical scavenging activity of the cranberry extract and its fractions was investigated on stable 2,2-diphenyl-1-picrylhydrazyl (DPPH and reactive hydroxyl radicals employing electron spin resonance (ESR spectroscopy. The most effective fractions were those containing vitamin C (AADPPH= AAOH=100%, neutral (AADPPH=89.50% and AAOH=43.11% and acidic (AADPPH=83.98% and AAOH=38.58% phenols. The presence of vitamin C, abstracted from cranberry extract, was determined by Fe(III-mediated ascorbate oxidation which yields characteristic ESR doublet spectrum of ascorbyl radical.

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

    Science.gov (United States)

    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

  15. MOLECULARLY IMPRINTED SOLID PHASE EXTRACTION FOR TRACE ANALYSIS OF DIAZINON IN DRINKING WATER

    OpenAIRE

    M. Rahiminejad ? S. J. Shahtaheri ? M. R. Ganjali ? A. Rahimi Forushani ? F. Golbabaei

    2009-01-01

    Amongst organophosphate pesticides, the one most widely used and common environmental contaminant is diazinon; thus methods for its trace analysis in environmental samples must be developed. Use of diazinon imprinted polymers such as sorbents in solid phase extraction, is a prominent and novel application area of molecular imprinted polymers. For diazinon extraction, high performance liquid chromatography analysis was demonstrated in this study. During optimization of the molecular imprinted ...

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

    Science.gov (United States)

    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

  17. Solid-phase extraction clean-up of ciguatoxin-contaminated coral fish extracts for use in the mouse bioassay

    OpenAIRE

    Wong, Chun-Kwan

    2009-01-01

    Abstract Florisil solid-phase extraction (SPE) cartridges were used for purifying ciguatoxin-contaminated (CTX-contaminated) coral fish extracts, with an aim to removing extracted lipid but retaining optimal level of CTXs in the purified fractions. CTX-containing fraction (target fraction) in fish ether extract was isolated and purified by eluting through a commercially available Florisil cartridge with hexane-acetone-methanol solvent mixtures of increasing polarity (hexane-acetone...

  18. Micro-solid phase extraction of ochratoxin A, and its determination in urine using capillary electrophoresis

    International Nuclear Information System (INIS)

    We describe a simple, environmentally friendly and selective technique for the determination of ochratoxin A (OTA) in urine. It involves (a) the use of a molecularly imprinted polymer as a sorbent in micro-solid-phase extraction in which the sorbent is contained in a propylene membrane envelope, and (b) separation and detection by capillary electrophoresis (CE). Under optimized conditions, response is linear in the range between 50 and 300 ng mL?1 (with a correlation coefficient of 0.9989), relative standard deviations range from 4 to 8 %, the detection limit for OTA in urine is 11.2 ng mL?1 (with a quantification limits of 32.5 ng mL?1) which is lower than those of previously reported methods for solid-phase extraction combined with CE. The recoveries of OTA from urine spiked at levels of 50, 150 and 300 ng mL?1 ranged from 93 to 97 %. (author)

  19. Utilizing ion-pairing hydrophilic interaction chromatography solid phase extraction for efficient glycopeptide enrichment in glycoproteomics

    DEFF Research Database (Denmark)

    Mysling, Simon; Palmisano, Giuseppe; Højrup, Peter; Thaysen-Andersen, Morten

    2010-01-01

    Glycopeptide enrichment is a prerequisite to enable structural characterization of protein glycosylation in glycoproteomics. Here we present an improved method for glycopeptide enrichment based on zwitter-ionic hydrophilic interaction chromatography solid phase extraction (ZIC-HILIC SPE) in a microcolumn format. The method involves TFA ion pairing (IP) to increase the hydrophilicity difference between glycopeptides and nonglycosylated peptides. Three mobile phases were investigated, i.e., 2% for...

  20. Determination of Phthalate Esters in Drinking Water using Solid-phase Extraction and Gas Chromatography

    OpenAIRE

    W. Kanchanamayoon; P. Prapatpong

    2010-01-01

    Phthalate esters are widely used as plasticizer. They can migrate from plastic materials to the environment. Some of these compounds may have risk to get cancer. Phthalate esters; dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP) and bis(2-ethylhexyl) phthalate (DEHP) were extracted simultaneously using solid-phase and analyzed by gas chromatograph. The percentage recoveries were carried out on LC-18 and Florisil cartridge using various eluting solvent. The 6 mL Flori...

  1. Solid-phase extraction approach in comprehensive analysis of wort and beer samples.

    Czech Academy of Sciences Publication Activity Database

    ?melík, Richard; Žídková, Jitka; Bobálová, Janette

    Praha : Institute of Chemical Technology, 2011 - (Pulkrabová, J.; Tomaniová, M.). s. 237 ISBN 978-80-7080-795-8. [International Symposium on Recent Advances in Food Analysis /5./. 01.11.2011-04.11.2011, Praha] R&D Projects: GA MŠk 1M06030; GA MŠk 1M0570 Institutional research plan: CEZ:AV0Z40310501 Keywords : solid phase extraction * carbohydrates * beer Subject RIV: CB - Analytical Chemistry, Separation

  2. HPLC WITH SOLID PHASE EXTRACTION FOR IDENTIFICATION AND DIAGNOSIS OF ORGANOPHOSPHOROUS POISONING IN GOATS

    Directory of Open Access Journals (Sweden)

    S. Manna

    2014-12-01

    Full Text Available High performance liquid chromatographic determination of organophosphorous compound has been done by reverse phase chromatography in goats. The goats were dying showing the symptoms of organophosphorous poisoning. The viscera and stomach contents sample were received from Project Co-Ordinator, Animal Disease Research Institute, Phulnakhara, Cuttack, Orissa. The analysis of samples by HPLC with UV detector after cleaning up in Solid Phase Extraction (SPE revealed presence of malathion that was later quantified.

  3. An Ion-Pair Reagent Incorporated Polystyrene Nanofiber Applied to Solid Phase Extraction of 5-Hydroxytryptamine in Human Plasma

    Scientific Electronic Library Online (English)

    Yu, Wang; Xiaoling, Zhou; Yuqin, Ma; Xuejun, Kang.

    2015-03-01

    Full Text Available Polystyrene (PS) nanofibers incorporated with ion-pair (IP) reagent, e.g., sodium dodecyl sulfonate (SDSn), were developed as functional adsorbents for the solid-phase extraction (SPE) of ionic neurotransmitter such as 5-hydroxytryptamine (5-HT), prior to the determination by high performance liquid [...] chromatography-fluorescence detection (HPLC-FLD). A comprehensive study was initiated to optimize the preconcentration step by exploring the main factors that affect the extraction/preconcentration efficiency of 5-HT, such as the composition of nanofibers, eluent and its volume, amount of adsorbent, pH and ionic strength. The validity of this method was investigated and optimal analytical performance was achieved including a wide dynamic range of 0.50-200 ng mL-1, detection limits of 0.50 ng mL–1 and precision (as RSD%) lower than 4% for both intra-day and inter-day assays. This method was then applied to the determination of 5-HT in human plasma with satisfactory results.

  4. Box-Behnken design in modeling of solid-phase tea waste extraction for the removal of uranium from water samples

    International Nuclear Information System (INIS)

    In this study, the solid-phase tea waste procedure was used for separation, preconcentration and determination of uranium from water samples by UV-Vis spectrophotometer. In addition, Box-Behnken experimental design was employed to investigated the influence of six variables including pH, mass of adsorbent, eluent volume, amount of 1-(2-pyridylazo)-2-naphthol (PAN); and sample and eluent flow rates on the extraction of analyte. High determination coefficient (R2) of 0.972 and adjusted-R2 of 0.943 showed the satisfactory adjustment of the polynomial regression model. This method was used for the extraction of uranium from real water samples.

  5. Solid phase extraction of uranium (VI) using penicillium chrysogenum immobilized on silica gel

    International Nuclear Information System (INIS)

    Uranium is a metal of strategic importance in the area of Nuclear Technology. It has due to its usage in power generation. Being a toxic element and due to environmental concerns its determination from water, soil and other samples has gained significance. The determination of traces of uranium in such samples requires a preconcentration step. Biosorption methods involving solid phase extraction utilizes various materials of biological origin, including bacteria, fungi, yeast, algae, etc. In the present work a solid phase extraction method for separation and enrichment of uranium (VI) was developed. A solid phase was prepared by immobilization 150 mg of Penicillium and 1.0 g silica. A 350 mg of Penicillium chrysogenum immobilized silica mixed with double distilled water packed in a glass column (150 mm length and 10 mm internal diameter) with wool as support and was systematically investigated to optimize the conditions for quantitative sorption and desorption of uranium (VI). It was determined spectrophotometrically using Arsenazo (III) at 650 nm

  6. Application of copolymer coated frits for solid-phase extraction of poly cyclic aromatic hydrocarbons in water samples

    Energy Technology Data Exchange (ETDEWEB)

    Rahimi, M., E-mail: m_rahimi543@yahoo.com [Department of Chemistry, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Young Researchers Society, Shahid Bahonar University of Kerman, P.O. Box 76169–133, Kerman (Iran, Islamic Republic of); Noroozian, E. [Department of Chemistry, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of)

    2014-07-11

    Graphical abstract: Electrodeposition and using of the copolymer of pyrrole and phenol for frit-SPE for the enrichment of organic pollutants from real samples and HPLC–UV analysis. - Highlights: • A copolymer of pyrrole and phenol was electrosynthesised on steel frit. • Coated frit was used for the first time as a SPE sorbent for PAHs in real samples. • Using the designed device was simple and it needs no vacuum or pressure system. - Abstract: 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 0.1–500 ng mL{sup ?1} (r{sup 2} > 0.98) and the LODs (S/N = 3) were obtained in the range of 0.01–0.08 ng mL{sup ?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 40 ng mL{sup ?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.

  7. Application of copolymer coated frits for solid-phase extraction of poly cyclic aromatic hydrocarbons in water samples

    International Nuclear Information System (INIS)

    Graphical abstract: Electrodeposition and using of the copolymer of pyrrole and phenol for frit-SPE for the enrichment of organic pollutants from real samples and HPLC–UV analysis. - Highlights: • A copolymer of pyrrole and phenol was electrosynthesised on steel frit. • Coated frit was used for the first time as a SPE sorbent for PAHs in real samples. • Using the designed device was simple and it needs no vacuum or pressure system. - Abstract: 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 0.1–500 ng mL?1 (r2 > 0.98) and the LODs (S/N = 3) were obtained in the range of 0.01–0.08 ng mL?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 40 ng mL?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

  8. Reducing the sulfur-dioxide binding power of sweet white wines by solid-phase extraction.

    Science.gov (United States)

    Saidane, Dorra; Barbe, Jean-Christophe; Birot, Marc; Deleuze, Hervé

    2013-11-01

    The high sulfur-dioxide binding power of sweet white wines may be reduced by extracting the naturally present carbonyl compounds from wine that are responsible for carbonyl bisulphites formation. The carbonyl compounds mainly responsible for trapping SO2 are acetaldehyde, pyruvic acid, and 2-oxoglutaric acid. The method employed was selective solid phase extraction, using phenylsulfonylhydrazine as a scavenging agent. The scavenging function was grafted onto a support prepared from raw materials derived from lignin. This approach is more acceptable to winemakers than the polymer media previously reported, as it reduces the possible contamination of wine to molecules already present in the wine making process. PMID:23768401

  9. Solid Phase Extraction Cleanup for Non-Polar and Moderately Polar Molecular Markers of PM2.5 Sources

    Science.gov (United States)

    A solid phase extraction cleanup step substantially improved analytical efficiency and data quality for measurements of non-polar and moderately polar organic molecular marker concentrations in airborne particulate matter.

  10. Determination of trace copper in food samples by flame atomic absorption spectrometry after solid phase extraction on modified soybean hull

    Energy Technology Data Exchange (ETDEWEB)

    Xiang Guoqiang, E-mail: xianggq@126.com [School of Chemistry and Chemical Engineering, Henan University of Technology, Zhengzhou 450001 (China); Zhang Yingming; Jiang Xiuming; He Lijun; Fan Lu; Zhao Wenjie [School of Chemistry and Chemical Engineering, Henan University of Technology, Zhengzhou 450001 (China)

    2010-07-15

    Soybean hull was chemically modified with citric acid and used as a solid phase extraction adsorbent for the determination of trace amounts of Cu{sup 2+} in food samples by flame absorption spectrometry (FAAS). The effect of pH, sample flow rate and volume, elution flow rate and volume and co-existing ions on the recovery of the analyte were investigated. The results showed that Cu{sup 2+} could be adsorbed on the modified soybean hull at pH 8.0 and eluted by 2.0 mL of 1.0 mol L{sup -1} HCl. Under the optimized conditions, the adsorption capacity of modified soybean hull was found to be 18.0 mg g{sup -1} for Cu{sup 2+}. The detection limit of the proposed method was 0.8 ng mL{sup -1} for Cu{sup 2+} with an enrichment factor of 18. The analytical result for the certified reference tea sample (GBW07605) was in a good agreement with the certified value. The proposed method has also been successfully applied to the determination of trace Cu{sup 2+} in dried sweet potato, lake water and milk powder, the recovery of Cu{sup 2+} for spiked samples was between 91% and 109.6%.

  11. Determination of trace copper in food samples by flame atomic absorption spectrometry after solid phase extraction on modified soybean hull

    International Nuclear Information System (INIS)

    Soybean hull was chemically modified with citric acid and used as a solid phase extraction adsorbent for the determination of trace amounts of Cu2+ in food samples by flame absorption spectrometry (FAAS). The effect of pH, sample flow rate and volume, elution flow rate and volume and co-existing ions on the recovery of the analyte were investigated. The results showed that Cu2+ could be adsorbed on the modified soybean hull at pH 8.0 and eluted by 2.0 mL of 1.0 mol L-1 HCl. Under the optimized conditions, the adsorption capacity of modified soybean hull was found to be 18.0 mg g-1 for Cu2+. The detection limit of the proposed method was 0.8 ng mL-1 for Cu2+ with an enrichment factor of 18. The analytical result for the certified reference tea sample (GBW07605) was in a good agreement with the certified value. The proposed method has also been successfully applied to the determination of trace Cu2+ in dried sweet potato, lake water and milk powder, the recovery of Cu2+ for spiked samples was between 91% and 109.6%.

  12. Matrix solid-phase dispersion versus ultrasound assisted extraction with solid-phase extraction in the HPLC analysis of furanocoumarins from fruits of Archangelica officinalis Hoffm

    Scientific Electronic Library Online (English)

    Anna, Oniszczuk; Krystyna, Skalicka-Wo& #378; niak; Tomasz, Oniszczuk; Monika, Waksmundzka-Hajnos; Kaziemirz, G& #322; owniak.

    2014-07-01

    Full Text Available Neste estudo, um eficiente método, a dispersão da matriz em fase sólida (DMFS), foi usado para a determinação simultânea de furanocoumarinas de frutos de Archangelica officinalis Hoffm. Amostras da planta foram preparadas pelo procedimento MSPD otimizado, utilizando C18 como sorvente. A análise foi [...] realizada por cromatografia líquida de alta eficiência com detector de arranjo de diodos (HPLC-DAD). A eficiência do método DMFS também foi comparada com a extração assistida por ultra-som associada à extração em fase sólida (SPE com USAE). O MSPD extraiu furanocoumarins (isoimperatorin, imperatorin, bergapteno, isopimpinellin, xantotoxina, umbeliferona e xanthotoxol) de Archangelica officinalis com recuperações satisfatórias que variam de 91,43 a 96,07% e desvio padrão relativo menor do que 4,34% . O limite de detecção das várias furanocoumarinas, encontra-se na faixa de 0,37 mg mL-1 para a xanthotoxol e 10,82 mg mL-1 para imperatorin. Os resultados apresentados no manuscrito revelam que o método DMFS é eficiente, simples, rápido e de fácil execuçaõ, e é adequado para o isolamento de furanocoumarins a partir da plantas. Abstract in english In this study an efficient matrix solid-phase dispersion (MSPD) method for the simultaneous HPLC analysis of furanocoumarins from fruits of Archangelica officinalis Hoffm. was performed. Herbal samples were prepared by an optimized MSPD procedure using C18 as sorbent. The analysis was performed by h [...] igh performance liquid chromatography with diode array detector (HPLC-DAD). The efficiency of the MSPD method was also compared with ultrasound assisted extraction with solid-phase extraction (USAE with SPE). The MSPD extracted furanocoumarins (isoimperatorin, imperatorin, bergapten, isopimpinellin, xanthotoxin, umbelliferone and xanthotoxol) from Archangelica officinalis with satisfactory recoveries ranging from 91.43% to 96.07% and relative standard deviations lower than 4.34%. The detection limit of various furanocoumarins was found to be in the range of 0.37 mg mL-1 for xanthotoxol to 10.82 mg mL-1 for imperatorin. The results presented in the paper reveal that MSPD is efficient, fast, simple and easy to perform method suitable for the isolation of furanocoumarins from herbs.

  13. Nanogold-Decorated Silica Monoliths as Highly Efficient Solid-Phase Adsorbent for Ultratrace Mercury Analysis in Natural Waters.

    Science.gov (United States)

    Huber, Jessica; Heimbürger, Lars-Eric; Sonke, Jeroen E; Ziller, Sebastian; Lindén, Mika; Leopold, Kerstin

    2015-11-01

    We propose a novel analytical method for mercury (Hg) trace determination based on direct Hg preconcentration from aqueous solution onto a gold nanoparticle-decorated silica monolith (AuNP@SiO2). Detection of Hg is performed after thermal desorption by means of atomic fluorescence spectrometry. This new methodology benefits from reagent-free, time- and cost-saving procedure, due to most efficient solid-phase adsorbent and results in high sensitive quantification. The excellent analytical performance of the whole procedure is demonstrated by a limit of detection as low as 1.31 ng L(-1) for only one-min accumulation duration. A good reproducibility with standard deviations ?5.4% is given. The feasibility of the approach in natural waters was confirmed by a recovery experiment in spiked seawater with a recovery rate of 101%. Moreover, the presented method was validated through reference analysis of a submarine groundwater discharge sample by cold vapor-atomic fluorescence spectrometry resulting in a very good agreement of the found values. Hence the novel method is a very promising new tool for low-level Hg monitoring in natural waters providing easy-handling on-site preconcentration, reagent-free stabilization as well as reagent-free, highly sensitive detection. PMID:26460188

  14. Magnetic multiwall carbon nanotubes modified with dual hydroxy functional ionic liquid for the solid-phase extraction of protein.

    Science.gov (United States)

    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

  15. Separation and Purification of Sulforaphane from Broccoli by Solid Phase Extraction

    Directory of Open Access Journals (Sweden)

    Kyung Ho Row

    2011-03-01

    Full Text Available A simple solid-phase extraction (SPE method for the determination of sulforaphane in broccoli has been developed. The optimal conditions were found to be use of a silica SPE cartridge, and ethyl acetate and dichloromethane as washing and eluting solvents, respectively, which could eliminate interferences originating from the broccoli matrix. The extracts were sufficiently clean to be directly injected into high-performance liquid chromatography (HPLC for further chromatographic analysis. Good linearity was obtained from 0.05 to 200 ?g/mL (r = 0.998 for sulforaphane with the relative standard deviations less than 3.6%. The mean recoveries of sulforaphane from broccoli were more than 90.8% and the detection limit (S/N = 3:1 was 0.02 ?g/mL. The SPE method provides a higher yield of sulforaphane from crude extracts compared to conventional liquid-liquid extraction.

  16. Matrix solid-phase dispersion extraction of organophosphorus pesticide using SiO2-poly(N-vinylimidazole)

    Science.gov (United States)

    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 0.8?g/g.

  17. Matrix solid-phase dispersion extraction of organophosphorus pesticide using SiO2-poly(N-vinylimidazole)

    International Nuclear Information System (INIS)

    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 0.8?g/g.

  18. VOLATILE COMPOUNDS OF LITHRAEA CAUSTICA (LITRE) DETERMINATED BY SOLID PHASE MICRO-EXTRACTION (SPME)

    Scientific Electronic Library Online (English)

    JUAN A, GARBARINO; GIUSEPPE, SALVATORE; MARISA, PIVANOVO; MARÍA CRISTINA, CHAMY; MARCELLO, NICOLETTI; ALFREDO, DE IOANNES.

    2002-12-01

    Full Text Available De las partes áereas de Lithraea caustica y usando la técnica de Micro-Extracción en Fase Sólida (MEFS), fueron identificados y cuantificados los principales compuestos volátiles: los monoterpenos, mirceno, a -pineno, p-cimeno y limoneno, y el sesquiterpeno cariofileno. [...] Abstract in english The head space of the aerial parts of Lithraea caustica was analyzed by Solid Phase Micro-Extraction (SPME) technique, obtaining as main volatile compounds the monoterpenes, myrcene, a -pinene, , p-cymene and limonene, as well as the sesquiterpene caryophylene. [...

  19. Solid phase extraction and chromatographic determination of pesticide residues in water samples: DDT and its metabolites

    International Nuclear Information System (INIS)

    Solid phase extraction cartridge embedded with octadecyl C/sub 18/ chain bounded to silica particles were used for the isolation and trace enrichment of pesticides from water samples collected from cotton, rice growing and municipal areas. The eluents were analyzed with HPLC using methanol (100%) as mobiles phase at different UV-Visible wavelengths. DDT and its metabolites were found in all areas but were not present in all samples. Concentration of pesticide residues varies from sample to sample and was in the range of 0.017 ng ml/sup -1/. Overall, recoveries ranged from 84%-91% for all target pesticides. (author)

  20. Application of Reversed-Phase Solid Phase Extraction for the HPLC Analysis of Microcystins in Water

    Energy Technology Data Exchange (ETDEWEB)

    Kim, M.H. [Petroleum Quality Inspection Institute, Kyungki-do (Korea); Kim, T.S. [National Institute of Environmental Research, Seoul (Korea); Kim, T.K. [Chongju University, Chongju (Korea); Park, S.K. [National Institute of Environmental Research, Seoul (Korea)

    2000-06-01

    To determine the concentrations of microcystins present in lake water or in tap water using high performance liquid chromatography, it is necessary to concentrate a large volume of water samples (about 20 L) into very small volume (0.1-0.3 mL). Concentration can be conveniently done when disc type solid phase extraction (SPE) apparatus is used. Using this apparatus we have investigated the recovery rates of three kinds of microcystins, RR, YR, LR, however, that the appropriate selection of the disc conditioning and eluting solvents and reproducible reconcentration process after SPE will improve both the recovery rates and the reproducibilities. (author). 19 refs., 3 tabs.

  1. Chromatographic Separations Using Solid-Phase Extraction Cartridges: Separation of Wine Phenolics

    Science.gov (United States)

    Brenneman, Charles A.; Ebeler, Susan E.

    1999-12-01

    We describe a simple laboratory experiment that demonstrates the principles of chromatographic separation using solid-phase extraction columns and red wine. By adjusting pH and mobile phase composition, the wine is separated into three fractions of differing polarity. The content of each fraction can be monitored by UV-vis spectroscopy. When the experiment is combined with experiments involving HPLC or GC separations, students gain a greater appreciation for and understanding of the highly automated instrumental systems currently available. In addition, they learn about the chemistry of polyphenolic compounds, which are present in many foods and beverages and which are receiving much attention for their potentially beneficial health effects.

  2. Electric Field-Assisted Solid Phase Extraction: Study of Electrochromatographic Parameters with an Anionic Model Compound

    Scientific Electronic Library Online (English)

    Ricardo M., Orlando; Jarbas J. R., Rohwedder; Susanne, Rath.

    2015-02-01

    Full Text Available Electric field-assisted solid phase extraction using syringe type cartridges (E-SPE) is a recent approach with a high capacity to obtain differential selectivity and/or recovery in comparison with conventional solid phase extraction (SPE). In this work, E-SPE was employed for the extraction of the a [...] nionic dye sunset yellow. During the washing step the electric field was evaluated with the top electrode negatively (E-SPE(–/+)) or positively charged (E-SPE(+/–)) and the results were compared with conventional SPE to understand how the electrochromatographic parameters can influence the recovery of the dye. Using the E-SPE(–/+) the electric field can increase the elution of the dye from the cartridge by over 57-fold. This notable result can be attributed to the electrophoretic velocity of the dye in the direction of the flow rate of the eluent. These results demonstrated that E-SPE is an interesting approach to elute ionic compounds with reduced volumes of eluent or less amount of organic solvent.

  3. ?-Cyclodextrin cross-linked polymer as solid-phase extraction material coupled with the spectrophotometric method for the analysis of serum albumin

    Science.gov (United States)

    Wu, Min; Zhu, Xiashi

    2010-12-01

    The ?-cyclodextrin cross-linked polymer (?-CDCP) was synthesized and used as solid-phase extraction material to preconcentrate/analysis bovine serum albumin (BSA) coupled with UV-vis spectroscopy. The method based on the complex (BSA-phenylfluorone (PF)) adsorbed on ?-CDCP. Adsorption kinetics and various factors of the formation procedure of BSA-PF and its retention on ?-CDCP were investigated. The linear range and detection limit (DL) was 20.0-200.0 and 0.03 mg/L, respectively. Moreover, the ?-CDCP could be used repeatedly. The proposed method has been applied to analysis serum albumin with satisfactory results.

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

    Science.gov (United States)

    Y?lmaz, 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

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

    Science.gov (United States)

    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

  6. Gaseous Products of Incense Coil Combustion Extracted by Passive Solid Phase Microextraction Samplers

    Directory of Open Access Journals (Sweden)

    Wen-Hsi Cheng

    2015-06-01

    Full Text Available Burning incense indoors is a common behavior in Southeast Asia. In this investigation, needle trap samplers (NTS, a novel, green analytical technology is used for sampling gaseous combustion by-products from sandalwood incense coils. To extract indoor volatile organic compounds (VOCs, two NTS are prepared, one using 60–80 mesh and the other using 100–120 mesh divinylbenzene (DVB particles packed in 22-gauge stainless steel needles. This work compares extraction efficiency of an NTS and that of a commercially available 100 ?m polydimethylsiloxane solid phase microextration (PDMS-SPME fiber sampler. Experimental results indicated that the 100–120 mesh DVB-NTS performed best among all samplers during a 1 h sampling period. The main extracted compounds were toluene, ethylbenzene, propane, chloromethane, 1,3-butadiene, methanol and dichloromethane. The potential use of small badge-sized or pen-sized NTS for the indoor atmosphere and occupational hygiene applications is addressed.

  7. Hemimicelle capped functionalized carbon nanotubes-based nanosized solid-phase extraction of arsenic from environmental water samples

    International Nuclear Information System (INIS)

    The end functionalization of CNTs can introduce oxygen-containing negatively functional groups such as -COOH, -OH, or -C=O on their surface site. If cationic surfactant such as cetyltrimethylammonium chloride (CTAC) was added to the functionalized CNTs, then interactions such as hydrophobic and ionic may lead to formation of hemimicelle/admicelle aggregates on the CNTs, a new kind of adsorbents, namely, the hemimicelle capped CMMWCNTs, is obtained. The application of the hemimicelle capped carbon nanotubes-based nanosized solid-phase extraction (SPE) adsorbents in environmental analysis is reported for the first time using arsenic as model target. The effect of adsorption and desorption conditions for arsenic including the amount of surfactant, initial pH of sample solution, the ultrasonic time of sample solution, the amount of electrolyte, flow rate, eluent and its amount were investigated and optimized prior to its determination by atomic fluorescence spectrophotometry (AFS). Arsenic can be quantitatively retained on the hemimicelle capped CMMWCNTs at pH 5-6 from sample volume up to 500 mL and then eluted completely with 2 mol L-1 HNO3 in the presence of 10 mg L-1 CTAC. The method detection limit for arsenic determination with AFS detection was 2 ng L-1, and the relative standard deviation (RSD, n = 11) was 5.3% at the 0.5 ?g L-1 level. The recoveries of arsenic in the spiked environmental water samples ranged from 94% to 104.29% with 500 mL of water sample. The proposed method has been applied successfully to the analysis of arsenic in aqueous environmental samples, which demonstrates the hemimicelle capped CMMWCNTs can be an excellent SPE adsorbents for arsenic pretreatment and enrichment from real water samples

  8. Monitoring of chloropesticide methoxychlor preconcentration from waste water using hplc - solid phase extraction (abstract)

    International Nuclear Information System (INIS)

    The method involves preconcentration of methoxychlor by solid phase extraction (SPE) with 1 mL silica based C-18 and 3 mL polymer based C-18 cartridge and then quantification by high performance liquid chromatography with UV detector (HPLC-UV). Optimization of HPLC parameters was done by determining max of methoxychlor on a double beam UV/Visible spectrophotometer, flow rate of mobile phase on reversed phase columns. Lowest detection limit for methoxychlor dissolved in water and methanol was 0.2ppm and 0.1ppm respectively. For solid phase extraction recovery studies and effect of different parameters such as initial concentration of analyte 0.01 to 0.05 ppm, loading rate 1 and 2mL/min, nature of desorbing solvent (methanol, ethyl acetate and acetonitrile) were investigated. Periodic self degradation of methoxychlor, and reusing potential of both SPE materials was also explored. Lower initial concentrations and slower loading rate of methoxychlor solutions gave improved recoveries. Recoveries were in the range of 80 to 90% for new SPE cartridge and reduced to 35 to 57% for once used silica based C-18 tubes. It was around 73 % for HLB C18 on their second use, and decreased on their repeated reuse. Lastly recoveries for stimulant and real waste water samples were determined to be 77 and 60% respectively. (author)

  9. Solid phase extraction and spectrophotometric determination of palladium with 2-(2-quinolylazo-5-diethylaminobenzoic acid

    Directory of Open Access Journals (Sweden)

    WEIZU YANG

    2006-07-01

    Full Text Available Asensitive, selective and rapid method for the determination of palladium based on the rapid reaction of palladium(II with 2-(2-quinolylazo-5-diethylaminobenzoic acid (QADEAB and the solid phase extraction of the Pd(II –QADEAB chelate with a reversed phase polymer-based C18 cartridge was developed. In the presence of 0.05 – 0. 5 mol/L of hydrochloric acid solution and cetyl trimethylammonium bromide (CTAB medium, QADEAB reacts with palladium(II to form a violet complex with a mole ratio 1:2 (palladium to QADEAB. The chelate was enriched by solid phase extraction with a reversed phase polymer-based C18 cartridge. An enrichment factor of 200 was obtained by elution of the chelate form the cartridge with the minimal amount of isopentyl alcohol. The molar absorptivity of the chelate in the isopentyl alcohol medium was 1.43 × 105 L mol-1 cm-1 at 628 nm. Beer’s law was obeyed in the range of 0.01 – 1.2 mg/mL. The relative standard deviation for eleven replicate samples at the 0.2 mg/L level was 2.18 %. The attained detection limit amounted to 0.02 mg/L in the original samples. This method was applied to the determination of palladium in environmental samples with good results.

  10. An Economical Online Solid-Phase Extraction LC-MS/MS Method for Quantifying Methylprednisolone.

    Science.gov (United States)

    Hu, Xingjiang; Zheng, Yunliang; Wu, Guolan; Liu, Jian; Chen, Junchun; Huang, Mingzhu; Zhou, Huili; Wu, Lihua; Shen-Tu, Jianzhong

    2015-07-01

    An economical, reproducible and automated online solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry method was developed to quantify methylprednisolone in human plasma. The method was validated in terms of selectivity, precision/accuracy, process efficiency, stability, cartridge reproducibility and carryover studies. Sample pretreatment was performed by protein precipitation and elimination using methanol followed by water dilution. Then, the mixture was passed onto the HySphere C8 EC-SE online solid-phase extraction cartridge followed by the separation of the analytes on an Agilent Eclipse XDB column. Electrospray ionization in positive ion mode and multiple reaction monitoring were used to monitor the ion transitions at m/z 375.4/160.8 for methylprednisolone, and m/z 361.2/147.0 for prednisolone. The calibration curve ranged from 5.25 to 525 ng/mL. Meanwhile both the intra-day and inter-day precision values (relative standard deviation) were within 4.45%. The method which turns out to be less laborious, faster and lower consumable cost per sample has already been successfully applied to a pharmacokinetic study in which the oral administration of 16 mg methylprednisolone was conducted in Chinese volunteers. PMID:25404561

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

    Science.gov (United States)

    Kaškonien?, 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. ?-Pinene, p-cymene, ?-ocimene, and ?-elemene were predominant in all extracts prepared in different ways. ?-Ocimene was the main compound (40-46%) in all extracts despite of the solvent used. No significant difference between the amount of ?-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

  12. Determination of quinolones in milk samples using a combination of magnetic solid-phase extraction and capillary electrophoresis.

    Science.gov (United States)

    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-?-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 ?g L(-1) with limits of detection ranging from 9 to 12 ?g L(-1) for the seven QNs. The absolute recoveries of the seven QNs at three different spiked levels (40, 150, and 400 ?g 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 ?g 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

  13. Principles and applications of colorimetric solid-phase extraction with negligible depletion

    International Nuclear Information System (INIS)

    Colorimetric solid-phase extraction (C-SPE) is an integrated technique in which an analyte is selectively concentrated onto a disk and then quantitated by diffuse reflectance spectroscopy. This paper describes the results of an investigation that applies the concept of negligible depletion (ND) to C-SPE, representing the first application of ND concepts to solid-phase extractions. The approach relies on passing the minimal volume of sample through the disk required to reach an equilibrium in which the concentration of analyte in the sample entering and exiting the disk are equal. At this point, the amount of analyte extracted by the disk is proportional to the sample concentration but is independent of the sample volume passed through the disk. With this new method, called C-SPE/ND, the precise measurement of sample volume is no longer necessary. The work herein details the general principles of this new methodology, and validates its basic tenets in an investigation of the extraction of the organic dye methyl violet. The analytical capabilities of C-SPE/ND are then demonstrated by its application to measurements of iodine. Iodine is a biocide increasingly used as a simple and effective disinfectant for water in locations where municipal water treatment systems are potentially compromised. Thus, the ability to operate C-SPE in an ND mode notably enhances the broad-based utility of this methodology as a reliable and an easy-to-use analysis tool for water quality assessments. Since iodine is also the biocide used on NASAs Space Shuttle, C-SPE/ND has the potential to overcome problems associated with the removal of air bubbles entrapped in a water sample in the microgravity environment encountered in space exploration. Extensions of C-SPE/ND to facile determinations of other water quality parameters with respect to both earth- and space-based needs are briefly discussed

  14. Extraction of pesticides from plants using solid phase microextraction and QuEChERS

    Scientific Electronic Library Online (English)

    Veronica C., Obuseng; Beauty M., Mookantsa; Harriet, Okatch; Ketlhatlogile, Mosepele; Nelson, Torto.

    2013-08-01

    Full Text Available A study employing dispersive solid phase extraction in the form of the quick, easy, cheap, effective, rugged and safe (QuEChERS) method and solid phase microextraction (SPME) for the cleanup of pesticides in plant samples from the Okavango Delta (Botswana) is presented. Concentration levels of aldri [...] n, 1,1-dichloro-2,4-bis[chlorophenyl]ethane (DDD), 1,1-dichloro-2,2-bis[p-chlorophenyl]ethylene(DDE), 1,1,1-trichloro-2,2-bis[p-chlorophenyl]ethane (DDT), dieldrin, endosulfan and endrin were investigated using gas chromatography with electron capture detection (GC-ECD) and confirmed with gas chromatography with high resolution time of flight mass spectrometry (GC-TOFMS). Parameters affecting the extraction efficiencies of both techniques were optimized. In the absence of CRMs for the plants under investigation, method validation and evaluation of the extraction efficiencies were achieved through spiking of Nymphaea nouchali (Tswii) leaves at two concentration levels with trichlorobenzene as an internal standard. Recoveries for both SPME and QuEChERS were in the range 61-95 %. The calibration plots were reproducible and linear (R² > 0.995) with limits of detection ranging from 0.102 to 1.693 µg L-1 for all the pesticides. The optimal conditions for QuEChERS and SPME were applied to the extraction of pesticides residues from the edible parts (leaves, roots and/ or stems) of Asparagus africanus, Cleome hirta and Nymphaea nouchali plants. No pesticides were detected in the leaves and stems of all the plants studied. Aldrin and endosulfan were detected in the Nymphaea nouchali roots at concentrations of 3-21 µg kg-1 and 5-3 µg kg-1, respectively. Pentachlorobenzene (PCB) and hexachlorobenzene (HCB) were also detected but were not quantified.

  15. Combined liquid and solid-phase extraction improves quantification of brain estrogen content

    Directory of Open Access Journals (Sweden)

    Luke Remage-Healey

    2011-09-01

    Full Text Available Accuracy in quantifying brain-derived steroid hormones (‘neurosteroids’ has become increasingly important for understanding the modulation of neuronal activity, development, and physiology. Relative to other neuroactive compounds and classical neurotransmitters, steroids pose particular challenges with regard to isolation and analysis, owing to their lipid solubility. Consequently, anatomical studies of the distribution of neurosteroids have relied primarily on the expression of neurosteroid synthesis enzymes. To evaluate the distribution of synthesis enzymes vis-à-vis the actual steroids themselves, traditional steroid quantification assays, including radioimmunoassays (RIA, have successfully employed liquid extraction methods (e.g., ether, dichloromethane or methanol to isolate steroids from microdissected brain tissue. Due to their sensitivity, safety and reliability, the use of commercial enzyme immunoassays (EIA for laboratory quantification of steroids in plasma and brain has become increasingly widespread. However, EIAs rely on enzymatic reactions in vitro, making them sensitive to interfering substances in brain tissue and thus producing unreliable results. Here, we evaluate the effectiveness of a protocol for combined, two-stage liquid/solid phase extraction as compared to conventional liquid extraction alone for the isolation of estradiol (E2 from brain tissue. We employ the songbird model system, in which brain steroid production is pronounced and linked to neural mechanisms of learning and plasticity. This study outlines a combined liquid-solid phase extraction protocol that improves the performance of a commercial EIA for the quantification of brain E2 content. We demonstrate the effectiveness of our optimized method for evaluating the region specificity of brain E2 content, compare these results to established anatomy of the estrogen synthesis enzyme and estrogen receptor, and discuss the nature of potential EIA interfering substances.

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

    Science.gov (United States)

    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 (?-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 ?-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 ?g 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 ?-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

  17. Extração em fase sólida (SPE) e micro extração em fase sólida (SPME) de piretróides em água Solid-phase extraction (SPE) and solid-phase microextraction of pyrethroids in water

    OpenAIRE

    Wilma Regina Barrionuevo; Fernando Mauro Lanças

    2001-01-01

    The pyrethroids bifenthrin, permethrin, cypermethrin and deltamethrin were extracted by solid phase extraction (SPE) and solid phase microextraction (SPME). The analysis were performed on a gas chromatograph with electron capture detection (GC-ECD). Octadecil Silano-C18, Florisil and Silica stationary phases were studied for SPE. Better results were obtained for Florisil which gave recoveries from 80% to 108%. Pyrethroids extraction by SPME showed a linear response and a detection limit of 10...

  18. Surfactant-enhanced spectrofluorimetric determination of total aflatoxins from wheat samples after magnetic solid-phase extraction using modified Fe3O4 nanoparticles

    Science.gov (United States)

    Manafi, Mohammad Hanif; Allahyari, Mehdi; Pourghazi, Kamyar; Amoli-Diva, Mitra; Taherimaslak, Zohreh

    2015-07-01

    The extraction and preconcentration of total aflatoxins (including aflatoxin B1, B2, G1, and G2) using magnetic nanoparticles based solid phase extraction (MSPE) followed by surfactant-enhanced spectrofluorimetric detection was proposed. Ethylene glycol bis-mercaptoacetate modified silica coated Fe3O4 nanoparticles as an efficient antibody-free adsorbent was successfully applied to extract aflatoxins from wheat samples. High surface area and strong magnetization properties of magnetic nanoparticles were utilized to achieve high enrichment factor (97), and satisfactory recoveries (92-105%) using only 100 mg of the adsorbent. Furthermore, the fast separation time (less than 10 min) avoids many time-consuming cartridge loading or column-passing procedures accompany with the conventional SPE. In determination step, signal enhancement was performed by formation of Triton X-100 micelles around the analytes in 15% (v/v) acetonitrile-water which dramatically increase the sensitivity of the method. Main factors affecting the extraction efficiency and signal enhancement of the analytes including pH of sample solution, desorption conditions, extraction time, sample volume, adsorbent amount, surfactant concentration and volume and time of micelle formation were evaluated and optimized. Under the optimum conditions, wide linear range of 0.1-50 ng mL-1 with low detection limit of 0.03 ng mL-1 were obtained. The developed method was successfully applied to the extraction and preconcentration of aflatoxins in three commercially available wheat samples and the results were compared with the official AOAC method.

  19. On-line solid phase extraction of copper in water samples with flow injection flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Cetin, Tuelin; Uelgen, Ahmet; Tokalioglu, Serife [Department of Chemistry, Faculty of Science, Erciyes University, Kayseri (Turkey)

    2011-03-15

    An on-line solid phase extraction method for the preconcentration and determination of Cu(II) by flame atomic absorption spectrometry has been described. The procedure is based on the retention of Cu(II) ions at pH 6.0 on a minicolumn packed with Amberlite XAD-1180 resin impregnated with chrome azurol S. After preconcentration, Cu(II) ions adsorbed on the impregnated resin were eluted by 1 mol L{sup -1} HNO{sub 3} solution. Several parameters, such as pH, type of eluent, flow rates of sample and eluent solutions, amount of resin were evaluated. At optimized conditions, for 3.5 min of preconcentration time, the system achieved a detection limit of 1.0 {mu}g L{sup -1}, and a relative standard deviation of 1.2% at 0.2 {mu}g mL{sup -1} copper. An enrichment factor of 56-fold was obtained with respect to the copper determination. The proposed method was successfully validated by the analysis of standard reference material (TMDA 54.4 lake water) and recovery studies. The method was applied to the preconcentration of Cu(II) in natural water samples. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Temperature-responsive Solid-phase Extraction Column for Biological Sample Pretreatment.

    Science.gov (United States)

    Akimaru, Michiko; Okubo, Kohei; Hiruta, Yuki; Kanazawa, Hideko

    2015-01-01

    We have developed a novel solid-phase extraction (SPE) system utilizing a temperature-responsive polymer hydrogel-modified stationary phase. Aminopropyl silica beads (average diameter, 40 - 64 ?m) were coated with poly(N-isopropylacrylamide) (PNIPAAm)-based thermo-responsive hydrogels. Butyl methacrylate (BMA) and N,N-dimethylaminopropyl acrylamide (DMAPAAm) were used as the hydrophobic and cationic monomers, respectively, and copolymerized with NIPAAm. To evaluate the use of this SPE cartridge for the analysis of drugs and proteins in biological fluids, we studied the separation of phenytoin and theophylline from human serum albumin (HSA) as a model system. The retention of the analytes in an exclusively aqueous eluent could be modulated by changing the temperature and salt content. These results indicated that this temperature-responsive SPE system can be applied to the pretreatment of biological samples for the measurement of serum drug levels. PMID:26353953

  1. Solid phase extraction of iron and lead in environmental matrices on amberlite xad-1180/pv

    Scientific Electronic Library Online (English)

    Mustafa, Soylak; Mustafa, Tuzen; Ibrahim, Narin.

    2006-04-01

    Full Text Available A solid phase extraction procedure using Amberlite XAD-1180/Pyrocatechol violet (PV) chelating resin for the determination of iron and lead ions in various environmental samples was established. The procedure is based on the sorption of lead(II) and iron(III) ions onto the resin at pH 9, followed by [...] elution with 1 mol/L HNO3 and determination by flame atomic absorption spectrometry. The influence of alkaline, earth alkaline and some transition metals, as interferents, are discussed. The recoveries for the spiked analytes were greater than 95%. The detection limits for lead and iron by FAAS were 0.37 µg/L and 0.20 µg/L, respectively. Validation of the method described here was performed by using three certified reference materials (SRM 1515 Apple Leaves, SRM 2711 Montana Soil and NRCC-SLRS-4 Riverine Water). The procedure was successfully applied to natural waters and human hair.

  2. Solid phase extraction of iron and lead in environmental matrices on amberlite xad-1180/pv

    Directory of Open Access Journals (Sweden)

    Mustafa Soylak

    2006-04-01

    Full Text Available A solid phase extraction procedure using Amberlite XAD-1180/Pyrocatechol violet (PV chelating resin for the determination of iron and lead ions in various environmental samples was established. The procedure is based on the sorption of lead(II and iron(III ions onto the resin at pH 9, followed by elution with 1 mol/L HNO3 and determination by flame atomic absorption spectrometry. The influence of alkaline, earth alkaline and some transition metals, as interferents, are discussed. The recoveries for the spiked analytes were greater than 95%. The detection limits for lead and iron by FAAS were 0.37 µg/L and 0.20 µg/L, respectively. Validation of the method described here was performed by using three certified reference materials (SRM 1515 Apple Leaves, SRM 2711 Montana Soil and NRCC-SLRS-4 Riverine Water. The procedure was successfully applied to natural waters and human hair.

  3. Carbon nanotubes as solid-phase extraction sorbents prior to atomic spectrometric determination of metal species: A review

    International Nuclear Information System (INIS)

    Highlights: ? The use of CNTs as sorbent for metal species in solid phase extraction has been described. ? Physical and chemical strategies for functionalization of carbon nanotubes have been discussed. ? Published analytical methods concerning solid phase extraction and atomic spectrometric determination have been reviewed. - Abstract: New materials have significant impact on the development of new methods and instrumentation for chemical analysis. From the discovery of carbon nanotubes in 1991, single and multi-walled carbon nanotubes – due to their high adsorption and desorption capacities – have been employed as sorption substrates in solid-phase extraction for the preconcentration of metal species from diverse matrices. Looking for successive improvements in sensitivity and selectivity, in the past few years, carbon nanotubes have been utilized as sorbents for solid phase extraction in three different ways: like as-grown, oxidized and functionalized nanotubes. In the present paper, an overview of the recent trends in the use of carbon nanotubes for solid phase extraction of metal species in environmental, biological and food samples is presented. The determination procedures involved the adsorption of metals on the nanotube surface, their quantitative desorption and subsequent measurement by means of atomic spectrometric techniques such as flame atomic absorption spectrometry, electrothermal atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry/mass spectrometry, among others. Synthesis, purification and types of carbon nanotubes, as well as the diverse chemical and physical strategies for their functionalization are described. Based on 140 references, the performance and general properties of the applications of solid phase extraction based on carbon nanotubes for metal species atomic spectrometric determination are discussed.

  4. Carbon nanotubes as solid-phase extraction sorbents prior to atomic spectrometric determination of metal species: A review

    Energy Technology Data Exchange (ETDEWEB)

    Herrero Latorre, C., E-mail: carlos.herrero@usc.es [Universidad de Santiago de Compostela, Dpto. Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Alfonso X el Sabio s/n, 27002 Lugo (Spain); Alvarez Mendez, J.; Barciela Garcia, J.; Garcia Martin, S.; Pena Crecente, R.M. [Universidad de Santiago de Compostela, Dpto. Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Alfonso X el Sabio s/n, 27002 Lugo (Spain)

    2012-10-24

    Highlights: Black-Right-Pointing-Pointer The use of CNTs as sorbent for metal species in solid phase extraction has been described. Black-Right-Pointing-Pointer Physical and chemical strategies for functionalization of carbon nanotubes have been discussed. Black-Right-Pointing-Pointer Published analytical methods concerning solid phase extraction and atomic spectrometric determination have been reviewed. - Abstract: New materials have significant impact on the development of new methods and instrumentation for chemical analysis. From the discovery of carbon nanotubes in 1991, single and multi-walled carbon nanotubes - due to their high adsorption and desorption capacities - have been employed as sorption substrates in solid-phase extraction for the preconcentration of metal species from diverse matrices. Looking for successive improvements in sensitivity and selectivity, in the past few years, carbon nanotubes have been utilized as sorbents for solid phase extraction in three different ways: like as-grown, oxidized and functionalized nanotubes. In the present paper, an overview of the recent trends in the use of carbon nanotubes for solid phase extraction of metal species in environmental, biological and food samples is presented. The determination procedures involved the adsorption of metals on the nanotube surface, their quantitative desorption and subsequent measurement by means of atomic spectrometric techniques such as flame atomic absorption spectrometry, electrothermal atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry/mass spectrometry, among others. Synthesis, purification and types of carbon nanotubes, as well as the diverse chemical and physical strategies for their functionalization are described. Based on 140 references, the performance and general properties of the applications of solid phase extraction based on carbon nanotubes for metal species atomic spectrometric determination are discussed.

  5. Molecularly imprinted sol-gel silica for solid phase extraction of phenobarbital

    Scientific Electronic Library Online (English)

    Eduardo J., Pilau; Raquel G. C., Silva; Isabel C. F. S., Jardim; Fabio, Augusto.

    Full Text Available Sílica organicamente modificada e molecularmente impressa foi preparada através de um procedimento sol-gel simples, e avaliada como sorvente específico para extração em fase sólida (Solid Phase Extraction, SPE) de fenobarbital em amostras aquosas e forenses. As propriedades analíticas dessa sílica m [...] olecularmente impressa (MIS, molecularly imprinted silica) foram inicialmente avaliadas e o material determinado como específico para as espécies-alvo: o fator de impressão IF, medido como a razão entre o pico do fenobarbital em cromatogramas de MIS e NIS (sílica não-impressa) foi estimado como 58. Este valor é consideravelmente maior que aquele apresentado normalmente para sorventes de impressão convencional baseados em metacrilatos e sugere que interações não-específicas analito/sorvente são insignificantes no MIS. O material foi aplicado no isolamento de fenobarbital de amostras aquosas e plasma; limites de detecção de 10 e 62 µg mL-1, respectivamente, foram encontrados para essas amostras. Abstract in english A molecularly imprinted organically modified silica was prepared through a simple sol-gel procedure, and evaluated as specific sorbent for solid-phase extraction (SPE) of phenobarbital from aqueous and forensic samples. The analytical properties of the molecularly imprinted silica (MIS, non-imprinte [...] d sílica) were initially evaluated and the MIS was found to be specific towards the target species: the imprinting factor IF, measured as the ratio between phenobarbital peak areas in the MIS and NIS chromatograms, was estimated as 58. This value is considerably higher than those usually found for conventional methacrylate-based molecularly imprinted sorbents and suggests that non-specific analyte/sorbent interactions are insignificant in the MIS. This material is applied to the isolation of phenobarbital from aqueous samples and plasma; detection limit of 10 and 62 µg mL-1 was achieved for the former samples, respectively.

  6. Selective solid-phase extraction using molecularly imprinted polymer for analysis of methamidophos in water and soil samples.

    Science.gov (United States)

    Shen, Zhong-Lan; Yuan, Dong; Su, Qing-De; Zhang, Hui; Wang, Jun; Zhu, Jian-Hua; Liu, Yan-Ming

    2011-01-01

    An analytical methodology for the analysis of methamidophos in water and soil samples incorporating a molecularly imprinted solid-phase extraction process using methamidophos-imprinted polymer was developed. Binding study demonstrated that the polymer exhibited excellent affinity and high selectivity to the methamidophos. Evidence was also found by FT-IR analysis that hydrogen bonding between the CO(2)H in the polymer cavities and the NH(2) and P=O of the template was the origin of methamidophos recognition. The use of molecularly imprinted solid-phase extraction improved the accuracy and precision of the GC method and lowered the limit of detection. The recovery of methamidophos extracted from a 10.0 g soil sample at the 100 ng/g spike level was 95.4%. The limit of detection was 3.8 ng/g. The recovery of methamidophos extracted from 100 mL tap and river water at 1 ng/mL spike level was 96.1% and 95.8%, and the limits of detection were 10 and 13 ng/L respectively. These molecularly imprinted solid-phase extraction procedures enabled selective extraction of polar methamidophos successfully from water and soil samples, demonstrating the potential of molecularly imprinted solid-phase extraction for rapid, selective, and cost-effective sample pretreatment. PMID:21389628

  7. Sodium dodecyl sulfate coated ?-alumina support modified by a new Schiff base for solid phase extraction and flame-AAS determination of lead and copper ions

    Directory of Open Access Journals (Sweden)

    Ardeshir Shokrollahi

    2013-01-01

    Full Text Available A simple and fast approach for solid phase extraction is herein described, and used to determine trace amounts of Pb2+ and Cu2+ metal ions. The solid phase support is sodium dodecyl sulfate (SDS-coated ?-alumina modified with bis(2-hydroxy acetophenone-1,6-hexanediimine (BHAH ligand. The adsorbed ions were stripped from the solid phase by 6 mL of 4 M nitric acid as eluent. The eluting solution was analyzed by flame atomic absorption spectrometry (FAAS. The sorption recovery of metal ions was investigated with regard to the effects of pH, amount of ligand, ?-alumina and surfactant and the amount and type of eluent. Complexation of BHAH with Pb2+ or Cu2+ ions was examined via spectrophotometry using the HypSpec program. The detection limit for Cu2+ was 7.9 µg L-1 with a relative standard deviation of 1.67%, while that for Pb2+ was 6.4 µg L-1 with a relative standard deviation of 1.64%. A preconcentration factor of 100 was achieved for these ions. The method was successfully applied to determine analyte concentrations in samples of liver, parsley, cabbage, and water.

  8. Sodium dodecyl sulfate coated ?-alumina support modified by a new Schiff base for solid phase extraction and flame-AAS determination of lead and copper ions

    Scientific Electronic Library Online (English)

    Ardeshir, Shokrollahi; Morteza, Montazerozohori; Tahere, Mehrpour; Hossein, Tavallali; Batool Zare, Khafri; Zohreh, Montaseri.

    Full Text Available A simple and fast approach for solid phase extraction is herein described, and used to determine trace amounts of Pb2+ and Cu2+ metal ions. The solid phase support is sodium dodecyl sulfate (SDS)-coated ?-alumina modified with bis(2-hydroxy acetophenone)-1,6-hexanediimine (BHAH) ligand. The adsorbed [...] ions were stripped from the solid phase by 6 mL of 4 M nitric acid as eluent. The eluting solution was analyzed by flame atomic absorption spectrometry (FAAS). The sorption recovery of metal ions was investigated with regard to the effects of pH, amount of ligand, ?-alumina and surfactant and the amount and type of eluent. Complexation of BHAH with Pb2+ or Cu2+ ions was examined via spectrophotometry using the HypSpec program. The detection limit for Cu2+ was 7.9 µg L-1 with a relative standard deviation of 1.67%, while that for Pb2+ was 6.4 µg L-1 with a relative standard deviation of 1.64%. A preconcentration factor of 100 was achieved for these ions. The method was successfully applied to determine analyte concentrations in samples of liver, parsley, cabbage, and water.

  9. Use of Solid-Phase Extraction To Determine Ergosterol Concentrations in Plant Tissue Colonized by Fungi

    Science.gov (United States)

    Gessner, M. O.; Schmitt, A. L.

    1996-01-01

    At present, the ergosterol and acetate-to-ergosterol techniques are generally considered to be the methods of choice to quantify fungal biomass, growth rate, and productivity under natural conditions. Both methods rely on the accurate isolation and quantification of ergosterol, a major membrane component of eumycotic fungi. Taking advantage of the solid-phase extraction (SPE) technique, we present a novel method to determine the ergosterol concentration in lipid extracts derived from plant tissues and dead organic matter colonized by fungi. In this method, a primary alkaline extract is acidified and passed through a reversed-phase (C(inf18)) SPE column. The column is then washed with an alkaline methanol-water solution to eliminate interfering substances and increase pH and is thoroughly dried in air. Ergosterol is eluted with alkaline isopropanol. This eluting solvent was chosen to produce a strongly basic pH of the final extract and thus confer stability on the ergosterol molecule before high-performance liquid chromatography analysis. The recovery of ergosterol from plant tissues and the O(infhf) horizon of a woodland soil ranged from 85 to 98%, and the overall extraction efficiency was similar to that obtained by a conventional procedure involving liquid-liquid extraction. Potential pitfalls of ergosterol analysis by SPE include (i) insufficient acidification before sample loading on the extraction column, resulting in a poor affinity of ergosterol for the sorbent; (ii) incomplete drying of the sorbent bed before the elution step; and (iii) chemical breakdown of ergosterol after elution, which was found to be related to a low pH of the final extract and a high concentration of matrix compounds. When these pitfalls are avoided, SPE is an attractive alternative to existing methods of ergosterol analysis of environmental samples. PMID:16535229

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

    Science.gov (United States)

    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 0.1mol/L Na2HPO4 solution contained 1mol/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

  11. Determining plasma morphine levels using GC-MS after solid phase extraction to monitor drug levels in the postoperative period

    OpenAIRE

    Veronica Santos; Karin Jannet Vera López; Luciana Moraes Santos; Mauricio Yonamine; Maria José Carvalho Carmona; Silvia Regina Cavani Jorge Santos

    2008-01-01

    OBJECTIVE: To implement a selective and sensitive analytical method to quantify morphine in small volumes of plasma by gas-liquid chromatography-mass spectrometry (GC-MS), aimed at post-operatively monitoring the drug. METHOD: A gas-liquid chromatographic method with mass detection has been developed to determine morphine concentration in plasma after solid phase extraction. Morphine-d3 was used as an internal standard. Only 0.5 mL of plasma is required for the drug solid-phase extraction in ...

  12. Micro-solid-phase extraction coupled to desorption electrospray ionization-high-resolution mass spectrometry for the analysis of explosives in soil

    DEFF Research Database (Denmark)

    Bianchi, Federica; Gregori, Adolfo

    2015-01-01

    Home-made micro-solid-phase extraction (SPE) cartridges using different adsorbent materials were tested for the desorption electrospray ionization–high-resolution mass spectrometry (DESI-HRMS) determination of explosives like 2,4,6-trinitrotoluene, cyclotrimethylene-trinitramine, cyclotetramethylene-tetranitramine, pentaerythritol tetranitrate, and trinitrophenylmethylnitramine in soil samples. Quantitation limits in the low nanogram per kilogram range proved the reliability of the method for the detection of explosives at ultra-trace levels. The reduced sample preparation allowed for low costs and high-throughput analyses. Finally, the superior extraction capability of the method was proved by obtaining DESI-HRMS responses at least five times higher than those achieved by performing DESI-HRMS analyses of solid–liquid extracts spotted onto commercial polytetrafluoroethylene slides.

  13. Direct observation of solid-phase adsorbate concentration profile in powdered activated carbon particle to elucidate mechanism of high adsorption capacity on super-powdered activated carbon.

    Science.gov (United States)

    Ando, Naoya; Matsui, Yoshihiko; Matsushita, Taku; Ohno, Koichi

    2011-01-01

    Decreasing the particle size of powdered activated carbon (PAC) by pulverization increases its adsorption capacities for natural organic matter (NOM) and polystyrene sulfonate (PSS, which is used as a model adsorbate). A shell adsorption mechanism in which NOM and PSS molecules do not completely penetrate the adsorbent particle and instead preferentially adsorb near the outer surface of the particle has been proposed as an explanation for this adsorption capacity increase. In this report, we present direct evidence to support the shell adsorption mechanism. PAC particles containing adsorbed PSS were sectioned with a focused ion beam, and the solid-phase PSS concentration profiles of the particle cross-sections were directly observed by means of field emission-scanning electron microscopy/energy-dispersive X-ray spectrometry (FE-SEM/EDXS). X-ray emission from sulfur, an index of PSS concentration, was higher in the shell region than in the inner region of the particles. The X-ray emission profile observed by EDXS did not agree completely with the solid-phase PSS concentration profile predicted by shell adsorption model analysis of the PSS isotherm data, but the observed and predicted profiles were not inconsistent when the analytical errors were considered. These EDXS results provide the first direct evidence that PSS is adsorbed mainly in the vicinity of the external surface of the PAC particles, and thus the results support the proposition that the increase in NOM and PSS adsorption capacity with decreasing particle size is due to the increase in external surface area on which the molecules can be adsorbed. PMID:20851447

  14. Application of solid phase micro extraction (SPME) in profiling hydrocarbons in oil spill cases

    International Nuclear Information System (INIS)

    In environmental forensic, it is extremely important to have a fast and reliable method in identifying sources of spilled oil and petroleum products. In this study, solid phase micro extraction (SPME) method coupled to gas chromatography-mass spectrometry was developed for the analysis of hydrocarbons in diesel and petroleum contaminated soil samples. Optimization of SPME parameters such as extraction time, extraction temperature and desorption time, was performed using 100-?m poly dimethylsiloxane (PDMS) fiber. These parameters were studied at three levels by means of a central composite experimental design and the optimum experimental conditions were determined using response surface method. The developed SPME method was applied to determine the profiles of hydrocarbons in several oil contaminated soil sample. The SPME method was also used to study the effects of weathering on the profiles of hydrocarbons in unleaded gasoline, diesel and kerosene contaminated soil samples. After several days, significant losses of the lighter hydrocarbons were observed compared to the heavier ones. From these data, SPME method can be used to differentiate possible candidate sources in oil spill cases. (author)

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

    Science.gov (United States)

    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, 3.5?m) 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

  16. Automation of solid-phase microextraction-gas chromatography-mass spectrometry extraction of eucalyptus volatiles.

    Science.gov (United States)

    Zini, Cláudia A; Lord, Heather; Christensen, Eva; de, Assis Teot?nio F; Caramão, Elina B; Pawliszyn, Janusz

    2002-03-01

    Solid-phase microextraction (SPME) coupled with gas chromatography (GC)-ion-trap mass spectrometry (ITMS) is employed to analyze fragrance compounds from different species of eucalyptus trees: Eucalyptus dunnii, Eucalyptus saligna, Eucalyptus grandis, and hybrids of other species. The analyses are performed using an automated system for preincubation, extraction, injection, and analysis of samples. The autosampler used is a CombiPAL and has much flexibility for the development of SPME methods and accommodates a variety of vial sizes. For automated fragrance analysis the 10- and 20-mL vials are the most appropriate. The chromatographic separation and identification of the analytes are performed with a Varian Saturn 4D GC-ITMS using an HP-5MS capillary column. Several compounds of eucalyptus volatiles are identified, with good reproducibility for both the peak areas and retention times. Equilibrium extraction provides maximal sensitivity but requires additional consideration for the effect of carryover. Preequilibrium extraction allows good sensitivity with minimal carryover. PMID:11954651

  17. Evaluation of Graphene for Dispersive Solid-Phase Extraction of Triazine and Neonicotine Pesticides from Environmental Water

    Scientific Electronic Library Online (English)

    Xiao Li, Wu; Lixuan, Meng; Yanhua, Wu; Yan-Yeung, Luk; Yongqiang, Ma; Yanli, Du.

    2015-01-01

    Full Text Available Neste trabalho, grafeno foi usado na extração em fase sólida dispersiva de 11 herbicidas triazina e 5 inseticidas neonicotina da água. As condições de extração como quantidade de grafeno, solvente de dessorção e pH da solução foram otimizados. Nas condiçõ [...] es otimizadas, um enriquecimento de alta eficiência foi alcançado na análise quantitativa dos pesticidas. Triazinas e neonicotinas foram determinadas por espectrometria de massas-cromatografia gasosa (GC-MS) e cromatografia líquida de alta eficiência acoplada à espectrometria de massas (LC-MS/MS), respectivamente. Os resultados indicaram que o grafeno foi um excelente adsorvente na adsorção de pesticidas. A recuperação dos pesticidas foi 83,0-108,9% com desvio padrão relativo (RSD) entre 2,4% e 12,3%. Os limites de detecção (LODs) variaram entre 0,03 ?g L-1 e 0,40 ?g L-1. Finalmente, o método proposto foi aplicado na análise de amostras reais, como água de torneira e de rio. Abstract in english In this work, graphene was used for dispersive solid-phase extraction of 11 triazine herbicides and 5 neonicotine insecticides from water. The extraction conditions such as the amount of graphene, the desorption solvent and the solution pH were optimized. [...] Under the optimal conditions, high ef?cient enrichment was achieved for the quantitative analysis of the pesticides. Triazines and neonicotines were determined by gas chromatograph-mass spectrometer (GC-MS) and high performance liquid chromatography electrospray tandem mass spectrometry (LC-MS/MS), respectively. The results indicated that graphene was an excellent adsorbent for the adsorption of pesticides. The recoveries of the pesticides were 83.0-108.9% with relative standard deviation (RSD) between 2.4% and 12.3%. The limits of detection (LODs) ranged from 0.03 ?g L-1 to 0.40 ?g L-1. Finally, the proposed method was applied for real sample analysis, such as tap and river water.

  18. Solid-phase extraction and capillary electrophoresis determination of phenols from soil after alkaline CuO oxidation.

    Science.gov (United States)

    Lima, Diana L D; Duarte, Armando C; Esteves, Valdemar I

    2007-09-01

    Alkaline CuO oxidation has been used on molecular-level analyses of phenols from organic matter in the last decades. This method, originally developed by Hedges and Ertel [Hedges, J.I., Ertel, J.R., 1982. Characterization of lignin by gas capillary chromatography of cupric oxide oxidation products. Anal. Chem. 54, 174-178] has several drawbacks that have limited is wider utilization. In this paper, we propose a modification of the method using a solid-phase extraction (SPE) instead of a liquid-liquid extraction. The SPE procedure using C18 cartridges was optimized to obtain high recoveries. The sequential elution with acetonitrile and methanol was found to be the most appropriate procedure. Recoveries of the 12 phenols in individual standard solutions ranged from 84% to 113% with relative standard deviation (RSD) lower than 12%. Experiments with a mixed standard solution highlighted the competition between the different phenols for the adsorbing sites. Recoveries decreased with polarity, reaching 30% for p-hydroxybenzoic acid when present at a concentration of 2.5 x 10(-3)M. A sample soil subjected to a CuO oxidation was used to test the reproducibility of the SPE method and good results were achieved, RSD ranged between 0.4% and 28.3%. The performance of the CE method was also evaluated by correlation coefficients (higher than 0.9920), linearity (higher than 99.902%) and limit of detection (ranging from 2.64 x 10(-6) to 1.25 x 10(-5)M). SPE procedure presents several advantages such as fast sample preparation, good recoveries, good accuracy, low sample handling and safety improvement due to reduced solvent/sample exposure and glassware management. PMID:17475307

  19. Optimisation of solid phase extraction of selected non-steroidal anti-inflammatory drugs by capillary zone electrophoresis.

    Czech Academy of Sciences Publication Activity Database

    ?apka, Lukáš; Lacina, P.; Vávrová, M.

    Greece, 2014. [International Symposium on Environmental Pollution and its Impact on Life in the Mediterranean Region /16./. 24.09.2014-27.09.2014, Ioannina] Institutional support: RVO:68081715 Keywords : solid phase extraction * capillary electrophoresis * non-steroidal anti-inflammatory drugs Subject RIV: CB - Analytical Chemistry, Separation

  20. The use of solid phase extraction method for analysis of residues of pesticides used in banana production in Costa Rica

    International Nuclear Information System (INIS)

    Different solid phase extraction devices were tested for the analysis of residues of eleven pesticides used in banana production in Costa Rica. The analysis was performed by using gas chromatograph equipped with NPD and ECD detectors. In general low recoveries and high variation coefficients were found for chlorothalonil, imazalil, terbufos and thiabendazole. For the other pesticides recoveries ranged between 60 and over 100%. (author)

  1. Solid-phase/supercritical-fluid extraction for liquid chromatography of phenolic compounds in freshwater microalgae and selected cyanobacterial species.

    Czech Academy of Sciences Publication Activity Database

    Klejdus, B.; Kopecký, Ji?í; Benešová, L.; Vacek, J.

    2009-01-01

    Ro?. 1216, ?. 5 (2009), s. 763-771. ISSN 0021-9673 R&D Projects: GA ?R GA525/07/0338 Grant ostatní: CZ(CZ) GP525/08/P540 Institutional research plan: CEZ:AV0Z50200510 Keywords : methanol * solid-phase extraction * phenolic compounds Subject RIV: EE - Microbiology, Virology Impact factor: 4.101, year: 2009

  2. Preconcentration of trace uranium from natural water with solid-phase extraction

    Energy Technology Data Exchange (ETDEWEB)

    Farzaneh Shemirani; Shiva Dehghan Abkenar; Mohammad Reza Jamali [University of Tehran, Faculty of Science, Tehran (Iran)

    2003-03-01

    In the present study, an effective method was used for the preconcentration and determination of uranium(VI) by solid-phase extraction (SPE). For this purpose, a microcolumn of alumina modified with sodium dodecyl sulfate (SDS) and 1-(2-pyridylazo)-2-naphthol (PAN) was prepared for the preconcentration of trace uranyl(VI) from water samples. The uranium(VI) was completely eluted with 6.0 mol dm{sup -3} HCl and determined by a spectrophotometric method with Arsenazo III. The SPE conditions were optimized by evaluating the effective factors such as pH, flow rate and masking agent. By the proposed method a preconcentration factor more than 150 was achieved. The average recovery of uranium(VI) was 99.8%. The relative standard deviation was 2.6% for ten replicate determinations of uranyl(VI) ion in a solution with a concentration of 50 ng cm{sup -3}. Some concomitant ions such as Cd{sup 2+}, Ni{sup 2+}, MoO{sub 4}{sup 2-}, Cu{sup 2+}, Th{sup 4+} and Ce{sup 3+}, which interfere in the determination process of uranium(VI), were masked with EDTA in the aqueous phase during the extraction process. The proposed method was successfully used for the determination of uranium in natural water. (author)

  3. Box-Behnken design in modeling of solid-phase tea waste extraction for the removal of uranium from water samples

    Energy Technology Data Exchange (ETDEWEB)

    Khajeh, Mostafa; Jahanbin, Elham; Ghaffari-Moghaddam, Mansour; Moghaddam, Zahra Safaei [Zabol Univ. (Iran, Islamic Republic of). Dept. of Chemistry; Bohlooli, Mousa [Zabol Univ. (Iran, Islamic Republic of). Dept. of Biology

    2015-07-01

    In this study, the solid-phase tea waste procedure was used for separation, preconcentration and determination of uranium from water samples by UV-Vis spectrophotometer. In addition, Box-Behnken experimental design was employed to investigated the influence of six variables including pH, mass of adsorbent, eluent volume, amount of 1-(2-pyridylazo)-2-naphthol (PAN); and sample and eluent flow rates on the extraction of analyte. High determination coefficient (R{sup 2}) of 0.972 and adjusted-R{sup 2} of 0.943 showed the satisfactory adjustment of the polynomial regression model. This method was used for the extraction of uranium from real water samples.

  4. Dynamic solid phase DNA extraction and PCR amplification in polyester-toner based microchip.

    Science.gov (United States)

    Duarte, Gabriela R M; Price, Carol W; Augustine, Brian H; Carrilho, Emanuel; Landers, James P

    2011-07-01

    A variety of substrates have been used for fabrication of microchips for DNA extraction, PCR amplification, and DNA fragment separation, including the more conventional glass and silicon as well as alternative polymer-based materials. Polyester represents one such polymer, and the laser-printing of toner onto polyester films has been shown to be effective for generating polyester-toner (PeT) microfluidic devices with channel depths on the order of tens of micrometers. Here, we describe a novel and simple process that allows for the production of multilayer, high aspect-ratio PeT microdevices with substantially larger channel depths. This innovative process utilizes a CO(2) laser to create the microchannel in polyester sheets containing a uniform layer of printed toner, and multilayer devices can easily be constructed by sandwiching the channel layer between uncoated cover sheets of polyester containing precut access holes. The process allows the fabrication of deep channels, with ~270 ?m, and we demonstrate the effectiveness of multilayer PeT microchips for dynamic solid phase extraction (dSPE) and PCR amplification. With the former, we found that (i) more than 65% of DNA from 0.6 ?L of blood was recovered, (ii) the resultant DNA was concentrated to greater than 3 ng/?L (which was better than other chip-based extraction methods), and (iii) the DNA recovered was compatible with downstream microchip-based PCR amplification. Illustrative of the compatibility of PeT microchips with the PCR process, the successful amplification of a 520 bp fragment of ?-phage DNA in a conventional thermocycler is shown. The ability to handle the diverse chemistries associated with DNA purification and extraction is a testimony to the potential utility of PeT microchips beyond separations and presents a promising new disposable platform for genetic analysis that is low cost and easy to fabricate. PMID:21557576

  5. Extraction and on-fiber derivatization of chlorophenols in leather by internally cooled solid phase microextraction

    Scientific Electronic Library Online (English)

    Cristine D. de Souza, Silveira; Josias, Merib; Edmar, Martendal; Eduardo, Carasek.

    2012-12-01

    Full Text Available Neste estudo é proposto um novo procedimento analítico para a determinação de fenóis em amostras de couro utilizando a técnica de microextração em fase sólida refrigerada internamente (CF-SPME) com derivatização direta na fibra e cromatografia gasosa acoplada a espectrometria de massas com monitoram [...] ento de íons selecionados (GC-SIM-MS). As condições experimentais para a extração e derivatização foram otimizadas utilizando procedimentos quimiométricos, sendo tempo de extração e temperatura da amostra de 5 min e 170 ºC, temperatura do recobrimento da fibra de 20 ºC, e exposição da fibra ao headspace de 70 µL do agente derivatizante bis(trimetilsilil)trifluor-acetamida por 23 min. Limites de detecção variaram entre 1,03 e 2,68 µg g-1 e o desvio padrão relativo (RSD) foi menor que 15% (n = 5). Estudos de recuperações em três níveis de concentração variaram entre 64,5 e 92,3%. Abstract in english This study proposes a new analytical procedure based on an internally cooled solid phase microextraction technique (CF-SPME) combined with on-fiber derivatization and gas chromatography-selected ion monitoring-mass spectrometry (GC-SIM-MS) for the determination of phenols extracted directly from lea [...] ther samples. The extraction and derivatization conditions were optimized using experimental designs, such as: extraction time and sample temperature of 5 min and 170 ºC, fiber recoat temperature of 20 ºC, and exposing the fiber to the headspace of 70 µL of bis(trimethylsylyl)trifluoro-acetamide derivatizing agent for 23 min. Detection limits ranging from 1.03 to 2.68 µg g-1 and relative standard deviation (RSD) lower than 15% (n = 5) were obtained. The recovery was studied at three concentration levels and excellent recoveries ranging from 64.5 to 92.3% were obtained.

  6. Core-Shell Diamond as a Support for Solid-Phase Extraction and High-Performance Liquid Chromatography

    International Nuclear Information System (INIS)

    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 size measurements. Larger (ca. 50 ?m) core-shell diamond particles have much higher surface areas, and analyte loading capacities in SPE than nonporous solid diamond particles. Smaller (ca. 3 ?m), normal and reversed phase, core-shell diamond particles have been used for HPLC, with 36,300 plates per meter for mesitylene in a separation of benzene and alkyl benzenes on a C18 adsorbent, and 54,800 plates per meter for diazinon in a similar separation of two pesticides.

  7. Core-Shell Diamond as a Support for Solid-Phase Extraction and High-Performance Liquid Chromatography

    Energy Technology Data Exchange (ETDEWEB)

    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 size measurements. Larger (ca. 50 ?m) core-shell diamond particles have much higher surface areas, and analyte loading capacities in SPE than nonporous solid diamond particles. Smaller (ca. 3 ?m), normal and reversed phase, core-shell diamond particles have been used for HPLC, with 36,300 plates per meter for mesitylene in a separation of benzene and alkyl benzenes on a C18 adsorbent, and 54,800 plates per meter for diazinon in a similar separation of two pesticides.

  8. Recent developments in automatic solid-phase extraction with renewable surfaces exploiting flow-based approaches

    DEFF Research Database (Denmark)

    Miró, Manuel; Hartwell, Supaporn Kradtap

    2008-01-01

    Solid-phase extraction (SPE) is the most versatile sample-processing method for removal of interfering species and/or analyte enrichment. Although significant advances have been made over the past two decades in automating the entire analytical protocol involving SPE via flow-injection approaches,on-line SPE assays performed in permanent mode lack sufficient reliability as a consequence of progressively tighter packing of the bead reactor, contamination of the solid surfaces and potential leakage of functional moieties. This article overviews the current state-of-the-art of an appealing tool for overcoming the above shortcomings, so-called bead-injection (BI) analysis, based on automated renewal of the sorbent material per assay exploiting the various generations of flow-injection analysis. It addresses novel instrumental developments for implementing BI and a number of alternatives for online chemical-derivatization reactions, and it pinpoints the most common instrumental detection techniques utilized. We present and discuss in detail relevant environmental and bioanalytical applications reported in the past few years.

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

    Science.gov (United States)

    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. Automated and portable solid phase extraction platform for immuno-detection of 17?-estradiol in water.

    Science.gov (United States)

    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 17?-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

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

    Science.gov (United States)

    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 carbadoxLeonardite humic acid were greater than those with Aldrich humic acid due to more interaction sites, i.e. carboxylic and phenolic functional moieties, present in the Leonardite humic acid. The results obtained suggest that many pharmaceuticals could be significantly bound to DOM, which alters their fate and mobility in the environment. PMID:23260244

  12. Determination of Phthalate Esters in Drinking Water using Solid-phase Extraction and Gas Chromatography

    Directory of Open Access Journals (Sweden)

    W. Kanchanamayoon

    2010-01-01

    Full Text Available Phthalate esters are widely used as plasticizer. They can migrate from plastic materials to the environment. Some of these compounds may have risk to get cancer. Phthalate esters; dimethyl phthalate (DMP, diethyl phthalate (DEP, dibutyl phthalate (DBP and bis(2-ethylhexyl phthalate (DEHP were extracted simultaneously using solid-phase and analyzed by gas chromatograph. The percentage recoveries were carried out on LC-18 and Florisil cartridge using various eluting solvent. The 6 mL Florisil (1 g with 5 mL of ethyl acetate as eluting solvent showed good recoveries in the range of 98.2-110.0% and the limit of determination in the range of 0.025-00.05 mg L-1. This proposed method was successfully applied to analysis of phthalates in drinking water. The contamination of DMP, DEP and DBP in drinking water samples were in the safe levels, except DEHP concentration in three samples were found out of regulated maximum admissible concentration.

  13. Determination of Inorganic Arsenic in Natural Water by Solid Phase Extraction

    International Nuclear Information System (INIS)

    Arsenic (As) is generally known for its toxicity. The toxicity and mobility of As in the environment are dependent on the chemical forms or species in which it exists. Arsenic (III) and (V) are the most often determined species in environmental water, soil and sediment, while organic As species are common constituents of biological tissue and fluids. It is well known that inorganic As, such as arsenite (As(III)) and arsenate (As(V)) are more toxic than their organic counterparts. This study is conducted to investigate the separation of each As inorganic species using solid phase extraction (SPE) technique. The technique utilizes SPE column for selective retention of As species, followed by elution and measurement of eluted fractions by inductively coupled plasma mass spectrometry (ICP-MS) for total As. Several type of SPE columns namely strongly anion exchange (SAX), strongly cation exchange (SCX), weakly anion exchange (WAX) and weakly cation exchange (WCX) were tested using three different types of media including deionized water, succinic acid and acetic acid containing inorganic As species. The SPE technique is suitable for on-site separation and preservation of As species from water. (author)

  14. Determination of phenols in landfill leachate-contaminated groundwaters by solid-phase extraction

    DEFF Research Database (Denmark)

    Ask Reitzel, Lotte; Ledin, Anna

    2002-01-01

    A solid-phase extraction method for phenols in landfill leachates was developed and optimized in order to solve the expected and observed problems associated with an anaerobic matrix containing high concentrations of salts and organic matter. Isolute ENV1 cartridges exhibited the best retention of phenols of the four sorbents examined, and was the only cartridge which a 1 L leachate sample could pass through. With the other cartridges, clogging made this impossible. The final method, which included 27 different phenols, gave detection limits of ,0.1 mg/L (drinking water concentration limit for pesticides) for most phenols (25), and for 12 phenols ,0.01 mg/ L. Recovery rates (determined for four concentrations in the range 1–25 mg/ L, two replicates of each) were in the range 79–104% (SD 1–12%), except for phenol (2661.3%) and 2-methoxyphenol (6264.2%). Up to 12 different phenols could be identified in leachates from three Danish landfills, ranging in concentration from 0.01 to 29 mg/ L, which is at the lower end of the concentration range usually found for phenols in landfill leachates (sub-mg/L to mg/L). ? 2002 Elsevier Science B.V. All rights reserved.

  15. Solid phase extractive preconcentration of uranium(VI) onto diarylazobisphenol modified activated carbon.

    Science.gov (United States)

    Starvin, A M; Rao, T Prasada

    2004-05-28

    Diarylazobisphenol (DAB) 1 and diarylazobisphenol modified carbon 2 were synthesized and characterised. The latter has been used for solid phase extractive preconcentration and separation of trace amounts of uranium(VI) from other inorganics. In this, a column mode preconcentration of uranium(VI) was carried out in the pH range 4.0-5.0, eluted with 1.0moll(-1) HCl and determined by an Arsenazo III spectrophotometric procedure. Calibration graphs were rectilinear over the uranium(VI) concentrations in the range 5-200mugl(-1). Five replicate determinations of 25mug of uranium(VI) present in 1l solution gave a mean absorbance of 0.032 with a relative standard deviation of 2.52%. The detection limit corresponding to three times the standard deviation of the blank was found to be 5mugl(-1). The accuracy of the developed preconcentration method in conjunction with the Arsenazo III procedure was tested by analysing MESS-3, a marine sediment certified reference material. Further, the above procedure has been successfully employed for analysis of uranium(VI) in soil and sediment samples. PMID:18969421

  16. A new functionalized resin for solid phase extraction of uranium(VI) from environmental samples

    International Nuclear Information System (INIS)

    Full text: A simple and sensitive column solid-phase extraction procedure for separation and preconcentration of U(VI) from natural water samples using Terephthalaldehyde bis(thiosemicarbazone)-functionalized Amberlite XAD-16 (XAD-16-TBT) resin prior to the determination by inductively coupled plasma atomic emission spectrometry has been developed. The new chelating resin was prepared by coupling terephthaladehyde bis(thiosemicarbzone) to Amberlite XAD-16 through an azo spacer. The functionalized resin was characterized by elemental analyses, FTIR, SEM, XRD and TG-DTG. The optimum experimental parameters such as pH (6.0), volume of sample (?250 mL), flow rate of the sample (2.5 mL min-1), and volume of the eluent (23 mol L-1 HNO3, 20mL) and sorption capacity of the chelating resin, were evaluated. The effect of the electrolytes and the cations on the preconcentration of metal ion was also investigated. The chelating resin could be reused for more than 10 cycles of sorption-desorption without any significant change in the sorption capacity. Studies with spiked samples for the optimization of the method showed that a recovery of >92% of the analyte was achieved with the developed resin. The present method has been successfully applied to the determination of the U(IV) in natural water samples collected from Kadapa district (Andhra Pradesh, India) water samples with good results such as relative standard deviation

  17. Determination of bismuth and cadmium after solid-phase extraction with chromosorb-107 in a syringe

    International Nuclear Information System (INIS)

    The determination of bismuth and cadmium by graphite furnace atomic absorption spectrometry (GFAAS) after solid-phase extraction (SPE) on Chromosorb-107 filled in a syringe was described. To retain the analytes, the sample solution treated with and without ammonium pyrolidine dithiocarbamate (APDC) was drawn into the syringe filled with Chromosorb-107 and discharged back manually. Bismuth and cadmium were quantitatively sorbed at pH ? 6 irrespective of whether the analyte was complexed with APDC prior to passing through the Chromosorb-107. Analyte elements sorbed on the resin were quantitatively eluted with 3.0 M of HNO3 again drawing and discharging the eluent into the syringe and ejected it back. Optimum flow rates of sample or eluent for sorption and elution processes were 20 ml min-1 for drawing and 20 ml min-1 for discharging in all cases. Bismuth and cadmium were analyzed by graphite furnace atomic absorption spectrometry. The elements could be concentrated by drawing and discharging several portions of sample successively but eluting only one time. The validity of the proposed method was checked with standard reference materials (NIST SRM 1515 Apple-Leaves, CWW-TM-E Waste Water and CRM-SW Sea Water). The analyte elements were quantitatively (>95%) recovered from different matrices irrespective of treated samples with APDC. Detection limits (?) were 0.8 and 1.2 ?g l-1 for Bi and Cd, respectively. The method can be characterized with fastness, simplicity, quantitative recovery and high reproducibility

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

    Science.gov (United States)

    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 0.005-2.4µgg(-1) for desmetryn, atrazine and terbumeton, and 0.005-1.5µgg(-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 0.09-0.39ngg(-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

  19. Comparison of various sorbent of solid phase extraction for analysis of polychlorinated biphenyls in transformer oil

    Energy Technology Data Exchange (ETDEWEB)

    Na, Y.; Seo, J.J. [Korea Basic Science Inst., Seoul (Korea, Republic of). Hazardous Substance Research Team; Kim, K.J. [Korea University, Seoul (Korea, Republic of). Dept. of Chemistry; Hong, J. [Kyung Hee Univ., Seoul (Korea, Republic of). College of Pharmacy

    2005-07-01

    Methods of analyzing polychlorinated biphenyls (PCBs) in transformer oils typically use diluted oil solutions to remove unwanted substances through a combination of acid cleanup and adsorption chromatography. However, the hydrocarbon transformer oils used in the process have similar physical and chemical properties as PCBs. In this study, solid phase extraction (SPE) was used to improve silica and florisil column cleanup for the monitoring of PCBs in transformer oil. The behavior of PCBs on various sorbent types were studied to separate transformer oil effectively. Cartridges containing pesticide residue consisting of N-vinylpyrrolidone and divinylbenzene, Aroclors, deca-chlorobiphenyl (deca-B), and tetrachloro-m-xylene were used with an HP-5MS column. The elution patterns collected from the solvent samples were measured by a gas chromatography electron capture detector (GC-ECD) for the Aroclors and deca-B, as well as by gas chromatography mass spectroscopy (GC-MS) for the transformer oil. In order to validate the method, 100 mg of transformer oil was spiked with 2 00 ng of Aroclors and 20 ng of deca-CB with n-hexane and a treatment of c-H{sub 2}SO{sub 4} until no change in the colour of the aqueous layer was observed. The portion of the extract containing the PCBs was then collected. The recovery measured by GC-ECD was then calculated. Results showed that the oil was captured for a longer time on the C8 sorbents. A reversed elution pattern of silica was observed. The HLB sorbent separated the PCBs and the transformer oil more efficiently than other sorbents. It was concluded that although the HLB sorbent was effective, a cleanup procedure was needed to secure the accurate quantification of PCBs. 7 refs., 1 tab., 1 fig.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    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.

  1. Microwave assisted extraction-solid phase extraction for high-efficient and rapid analysis of monosaccharides in plants.

    Science.gov (United States)

    Zhang, Ying; Li, Hai-Fang; Ma, Yuan; Jin, Yan; Kong, Guanghui; Lin, Jin-Ming

    2014-11-01

    Monosaccharides are the fundamental composition units of saccharides which are a common source of energy for metabolism. An effective and simple method consisting of microwave assisted extraction (MAE), solid phase extraction (SPE) and high performance liquid chromatography-refractive index detector (HPLC-RID) was developed for rapid detection of monosaccharides in plants. The MAE was applied to break down the structure of the plant cells and release the monosaccharides, while the SPE procedure was adopted to purify the extract before analysis. Finally, the HPLC-RID was employed to separate and analyze the monosaccharides with amino column. As a result, the extraction time was reduced to 17 min, which was nearly 85 times faster than soxhlet extraction. The recoveries of arabinose, xylose, fructose and glucose were 85.01%, 87.79%, 103.17%, and 101.24%, with excellent relative standard deviations (RSDs) of 1.94%, 1.13%, 0.60% and 1.67%, respectively. The proposed method was demonstrated to be efficient and time-saving, and had been applied to analyze monosaccharides in tobacco and tea successfully. PMID:25127612

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

    Science.gov (United States)

    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 presence of high levels of iodine in water can cause taste and odor issues that result in decreased water consumption by the crew. There are also concerns about potential impacts on thyroid function following exposure to high levels of iodine. With silver, there is a risk of developing argyria, an irreversible blue-gray discoloration of the skin, associated with long term consumption of water containing high concentrations of silver. The need to ensure that safe, effective levels of biocide are maintained in the potable water systems on the ISS provides a perfect platform for evaluating the suitability of CSPE technology for in-flight water quality monitoring. This paper provides an overview of CSPE technology and details on the silver and iodine methods used in the CWQMK. It also reports results obtained during in-flight analyses performed with the CWQMK and briefly discusses other potential applications for CSPE technology in both the spacecraft and terrestrial environments.

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

    Science.gov (United States)

    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...

  4. Novel sol-gel hybrid methyltrimethoxysilane-tetraethoxysilane as solid phase extraction sorbent for organophosphorus pesticides.

    Science.gov (United States)

    Wan Ibrahim, Wan Aini; Veloo, Krishna Veni; Sanagi, Mohd Marsin

    2012-03-16

    A novel sol-gel hybrid methyltrimethoxysilane-tetraethoxysilane (MTMOS-TEOS) was produced and applied as sorbent for solid phase extraction (SPE). Five selected organophosphorus pesticides (OPPs) were employed as model compounds to evaluate the extraction performance of the synthesized sol-gel organic-inorganic hybrid MTMOS-TEOS. Analysis was performed using gas chromatography-mass spectrometry. Several important SPE parameters were optimized. Under the optimum extraction conditions, the method using the sol-gel organic-inorganic hybrid MTMOS-TEOS as SPE sorbent showed good linearity in the range of 0.001-1 ?g L(-1), good repeatability (RSD 2.1-3.1%, n=5), low limits of detection at S/N=3 (0.5-0.9 pg mL(-1)) and limit of quantification (1-3 pg mL(-1), S/N=10). The performance of the MTMOS-TEOS SPE was compared to commercial C18 Supelclean SPE since C18 SPE is widely used for OPPs. The MTMOS-TEOS SPE method LOD was 500-600 × lower than the LOD of commercial C18 SPE. The LOD achieved with the sol-gel organic-inorganic hybrid MTMOS-TEOS SPE sorbent allowed the detection of these OPPs in drinking water well below the level set by European Union (EU) at 0.1 ?g L(-1) of each pesticides. The developed MTMOS-TEOS SPE method was successfully applied to real sample analysis of the selected OPPs from several water samples and its application extended to the analysis of several fruits samples. Excellent recoveries and RSDs of the OPPs were obtained from the various water samples (recoveries: 97-111%, RSDs 0.4-2.8%, n=3) and fruit samples (recoveries: 96-111%), RSDs 1-4%, n=5) using the sol-gel organic-inorganic hybrid MTMOS-TEOS SPE sorbent. Recoveries and RSDs of OPPs from river water samples and fruit samples using C18 Supelclean SPE sorbent were 91-97%, RSD 0.9-2.6, n=3 and 86-96%, RSD 3-8%, n=5, respectively). The novel sol-gel hybrid MTMOS-TEOS SPE sorbent demonstrate the potential as an alternative inexpensive extraction sorbent for OPPs with higher sensitivity for the OPPs. PMID:22326188

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

    Scientific Electronic Library Online (English)

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

    2012-12-01

    Full Text Available Estudo da composição da fração volátil do extrato aquoso de sachês de hortelã pimenta (Mentha piperita L.) através da extração em fase sólida. O princípio desse trabalho foi investigar a fração volátil do extrato aquoso de sachês comerciais de hortelã pimenta usando cromatografia gasosa com detector [...] es de ionização em chama e de massas. As amostras foram preparadas em condições similares às usadas para o preparo do chá caseiro. Os compostos voláteis foram isolados via método de extração em fase sólida com adsorvente Porapak Q e eluídos com acetona. Uma estimativa dos valores médios dos ácidos carboxílicos de cadeias média e curta ficou na faixa de 50-64 ?g kg-1, enquanto alcoóis alifáticos e hidrocarbonetos acíclicos tiveram valores menores do que 6 ?g kg-1. Os terpenos (275-382 ?g kg-1) foram os compostos majoritários alcançando 89 % dos sólidos totais. Um total de 16 compostos voláteis, entre eles, dodecano, acetoína, acetol, citral, geraniol e ácido octanóico foram descritos pela primeira vez no chá de hortelã pimenta. Esses resultados poderiam ser atribuídos aos diferentes métodos analíticos empregados, principalmente devido ao uso de diferentes técnicas de extração e pré-concentração. Em função da proporção menor de terpenos no extrato aquoso é razoável especular que as propriedades químicas do óleo essencial da hortelã pimenta não sejam totalmente reproduzidas com o consumo do chá caseiro. Abstract in english 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 meth [...] od (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 ?g kg-1 whilst aliphatic alcohols and acyclic hydrocarbons had values lower than 6 ?g kg-1. The major volatiles were terpenes (275-382 ?g 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.

  6. Monitoring of PAHs in air by collection on XAD-2 adsorbent then microwave-assisted thermal desorption coupled with headspace solid-phase microextraction and gas chromatography with mass spectrometric detection

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Ming-Chi; Chang, Wan-Ting [Central Taiwan University of Science and Technology, Department of Food Science, Taichung (Taiwan); Jen, Jen-Fon [National Chung-Hsing University, Department of Chemistry, Taichung (Taiwan)

    2007-02-15

    Microwave-assisted thermal desorption (MAD) coupled to headspace solid-phase microextraction (HS-SPME) has been studied for in-situ, one-step, sample preparation for PAHs collected on XAD-2 adsorbent, before gas chromatography with mass spectrometric detection. The PAHs on XAD-2 were desorbed into the extraction solution, evaporated into the headspace by use of microwave irradiation, and absorbed directly on a solid-phase microextraction fiber in the headspace. After desorption from the SPME fiber in the hot GC injection port, PAHs were analyzed by GC-MS. Conditions affecting extraction efficiency, for example extraction solution, addition of salt, stirring speed, SPME fiber coating, sampling temperature, microwave power and irradiation time, and desorption conditions were investigated. Experimental results indicated that extraction of 275 mg XAD-2, containing 10-200 ng PAHs, with 10-mL ethylene glycol-1 mol L{sup -1} NaCl solution, 7:3, by irradiation with 120 W for 40 min (the same as the extraction time), and collection with a PDMS-DVB fiber at 35 C, resulted in the best extraction efficiency. Recovery was more than 80% and RSD was less than 14%. Optimum desorption was achieved by heating at 290 C for 5 min. Detection limits varied from 0.02 to 1.0 ng for different PAHs. A real sample was obtained by using XAD-2 to collect smoke from indoor burning of joss sticks. The amounts of PAHs measured varied from 0.795 to 2.53 ng. The method is a simple and rapid procedure for determination of PAHs on XAD-2 absorbent, and is free from toxic organic solvents. (orig.)

  7. Solid-phase extraction of antioxidant compounds from commercial cranberry extract and its antiradical activity

    OpenAIRE

    Tumbas Vesna T.; ?ilas Sonja M.; ?anadanovi?-Brunet Jasna M.; ?etkovi? Gordana S.; Savatovi? Sla?ana M.

    2007-01-01

    This study is concerned with the fractionation and determination of major antioxidant compounds (phenols, flavonoids, anthocyanins and vitamin C) in commercial cranberry extract. The total content of phenolics, flavonoids and total and monomers of anthocyanins, determined spectrophotometrically, was 1.67 mg/g, 0.41 mg/g, 5.12 mg/g and 3.32 mg/g. The content of vitamin C, determined volumetrically, was 121.74 mg/g. Commercial cranberry extract was dissolved in 80 % acetone and the solution was...

  8. Simultaneous quantification of dissolved organic carbon fractions and copper complexation using solid-phase extraction

    International Nuclear Information System (INIS)

    Trace metal cycling in natural waters is highly influenced by the amount and type of dissolved organic C (DOC). Although determining individual species of DOC is unrealistic, there has been success in classifying DOC by determining operationally defined fractions. However, current fractionation schemes do not allow for the simultaneous quantification of associated trace metals. Using operational classifications, a scheme was developed to fractionate DOC based on a set of seven solid-phase extraction (SPE) cartridges. The cartridges isolated fractions based on a range of specific mechanisms thought to be responsible for DOC aggregation in solution, as well as molecular weight. The method was evaluated to determine if it can identify differences in DOC characteristics, including differences in Cu-DOC complexation. Results are that: (1) cartridge blanks were low for both DOC and Cu, (2) differences are observed in the distribution of DOC amongst the fractions from various sources that are consistent with what is known about the DOC materials and the mechanisms operative for each cartridge, (3) when present as a free cation, Cu was not retained by non-cationic cartridges allowing the method to be used to assess Cu binding, (4) the capability of the method to provide quantitative assessment of Cu-DOC complexation was demonstrated for a variety of DOC standards, (5) Cu was found to preferentially bind with high molecular weight fractions of DOC, and (6) estimated partitioning coefficients and conditional binding constants for Cu were similar to those reported elsewhere. The method developed describes DOC characteristics based on specific bonding mechanisms (hydrogen, donor-acceptor, London dispersion, and ionic bonding) while simultaneously quantifying Cu-DOC complexation. The method provides researchers a means of describing not only the extent of DOC complexation but also how that complex will be behave in natural waters.

  9. Flame atomic absorption spectrometric determination of trace amounts of heavy metal ions after solid phase extraction using modified sodium dodecyl sulfate coated on alumina

    International Nuclear Information System (INIS)

    A sensitive and selective solid phase extraction procedure for the determination of traces of Cu(II), Zn(II), Pb(II) and Fe(III) has been developed. An alumina-sodium dodecyl sulfate (SDS) coated on with meso-phenyl bis(indolyl) methane (MPBIM) was used for preconcentration and determination of Cu(II), Zn(II), Pb(II) and Fe(III) ions by flame atomic absorption spectrometry. The analyte ions were adsorbed quantitatively on adsorbent due to their complexation with MPBIM. Adsorbed metals were quantitatively eluted using 6 mL of 4 mol L-1 nitric acid. The effects of parameters such as pH, amount of alumina, amount of MBITP, flow rate, type and concentration of eluting agent were examined. The effects of interfering ions on the separation-preconcentration of analytes were also investigated. The relative standard deviation of the method was found to be less than 3.0%. The presented procedure was successfully applied for determination of analytes in real samples

  10. Serum protein profiling by miniaturized solid-phase extraction and matrix-assisted laser desorption/ionization mass spectrometry

    DEFF Research Database (Denmark)

    Callesen, Anne K; Mohammed, Shabaz; Bunkenborg, Jakob; Kruse, Torben A; Cold, Søren; Mogensen, Ole; Christensen, Rene dePont; Vach, Werner; Jørgensen, Per Erik; Jensen, Ole N

    2005-01-01

    Serum profiling by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) holds promise as a clinical tool for early diagnosis of cancer and other human diseases. Sample preparation is key to achieving reproducible and well-resolved signals in MALDI-MS; a prerequisite for translation of MALDI-MS based diagnostic methods to clinical applications. We have investigated a number of MALDI matrices and several miniaturized solid-phase extraction (SPE) methods for serum protein concen...

  11. Determination of selenoprotein P in human plasma by solid phase extraction and inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Bendahl, L.; Sidenius, U.; Gammelgaard, Bente

    2000-01-01

    A method based on solid phase extraction was developed for the determination of selenoprotein P as selenium in human plasma. Separation of selenoprotein P from other selenium-containing proteins was accomplished by immobilized metal-ion affinity chromatography. The selenium content was subsequently measured by inductively coupled plasma mass spectrometry (ICP-MS) monitoring the Se-82 isotope. Linear response was observed in the concentration range 0.3-70.8 mu g/l selenium as selenoprotein P with...

  12. Determination of Low Levels of Lead in Beer Using Solid-Phase Extraction and Detection by Flame Atomic Absorption Spectrometry

    OpenAIRE

    Nívia M. M. Coelho; Neto, Waldomiro B.; Borges, Simone S. O.; Alves, Vanessa N.

    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. Th...

  13. Screening for Anabolic Steroids in Urine of Forensic Cases Using Fully Automated Solid Phase Extraction and LC–MS-MS

    DEFF Research Database (Denmark)

    Andersen, David Wederkinck; Linnet, Kristian

    2014-01-01

    A screening method for 18 frequently measured exogenous anabolic steroids and the testosterone/epitestosterone (T/E) ratio in forensic cases has been developed and validated. The method involves a fully automated sample preparation including enzyme treatment, addition of internal standards and solid phase extraction followed by analysis by liquid chromatography-tandem mass spectrometry (LC-MS-MS) using electrospray ionization with adduct formation for two compounds. Urine samples from 580 forens...

  14. Solid-Phase Microextraction in Polymer Analysis - Extraction of Volatiles from Virgin and Recycled Polyamide 6.6

    OpenAIRE

    Gröning, Mikael

    2004-01-01

    The extraction and quantitative analysis of low molar mass compounds in polymers is an analytical challenge. It is also important from a practical point of view because the low molar mass compounds in time will migrate from the polymers into the surrounding environment. It is especially important to gain knowledge about the migrating compounds in applications such as medical implants, packaging materials and car interiors. The main aim of this thesis was to develop headspace solid phase micro...

  15. A new approach for cytokinin isolation from Arabidopsis tissues using miniaturized purification: pipette tip solid-phase extraction.

    Czech Academy of Sciences Publication Activity Database

    Sva?inová, Jana; Novák, Ond?ej; Pla?ková, Lenka; Lenobel, René; Holík, Josef; Strnad, Miroslav; Doležal, Karel

    2012-01-01

    Ro?. 8, _ (2012), s. 17. ISSN 1746-4811 R&D Projects: GA TA ?R TA01010861; GA AV ?R KAN200380801 Grant ostatní: GA MŠk(CZ) ED0007/01/01 Institutional research plan: CEZ:AV0Z50380511 Keywords : Pipette tip solid-phase extraction (PT-SPE) * Arabidopsis thaliana * Cytokinins Subject RIV: EC - Immunology Impact factor: 2.667, year: 2012

  16. Extraction chromatography of thorium ion by solid phase impregnated resins containing bi-functional organic extractants

    International Nuclear Information System (INIS)

    Macroporous methyl methacrylate polymeric resin (XAD-7) was investigated incorporating both acidic organophosphorous extractant (cyanex-301) and one neutral extractant from the followings: dibenzo 18 crown 6 (DB18C6), 18 crown 6 (18C6) and 15 crown 5 (15C5). The sorption behavior of the solvent impregnated resin (SIR) towards thorium ion, including batch equilibrium, and kinetic operation are described. Different factors affecting the uptake of metal ions and hence, the separation efficiency of the impregnated resins were investigated. The maximum uptakes of Th4+ were found to be 62.9, 66.7 and 92.6% for DB18C6, 18C6 and 15C5, respectively. Synergistic extraction of various CE towards thorium ion was tested with cyanex-301 to enhance the sorption capacity as well as the selective separation efficiency. A relatively high capacity of the chelating resin towards tetravalent thorium was found. The capacities of the co-impregnated resins were found to be 2.11, 2.42 and 3.85 mmol/g for DB18C6, 18C6 and 15C5, respectively. The impregnated resin containing cyanex-301 and 15C5 can be utilized for selective separation and pre-concentration of thorium ion from nitrate medium in the presence of several interfering metal ions. (author)

  17. Extraction of crocin from saffron (Crocus sativus) using molecularly imprinted polymer solid-phase extraction.

    Science.gov (United States)

    Mohajeri, Seyed Ahmad; Hosseinzadeh, Hossein; Keyhanfar, Fariborz; Aghamohammadian, Javad

    2010-08-01

    A new molecularly imprinted polymer for extraction of crocin from saffron stigmas was prepared using gentiobiose (a glycoside moiety in crocin structure) as a template. Crocin binding to gentiobiose imprinted polymer (Gent-MIP) was studied in comparison with a blank nonimprinted polymer in aqueous media. Affinity of the Gent-MIP for the crocin was more than the nonimprinted polymer at all concentrations. In Scatchard analysis, the number of binding sites in each gram of polymer (maximum binding sites) and dissociation constant of crocin to binding sites were 18.4 micromol/g polymer and 11.2 microM, respectively. The Gent-MIP was then used as the sorbent in an SPE method for isolation and purification of crocin from methanolic extract of saffron stigmas. The recovery of crocin, safranal and picrocrocin was determined in washing and elution steps. The Gent-MIP had significantly higher affinity for crocin than other compounds and enabled selective extraction of crocin with a high recovery (84%) from a complex mixture. The results demonstrated the possibility of using a part of a big molecule in preparing a molecularly imprinted polymer with a good selectivity for the main structure. PMID:20589782

  18. Dispersive Micro-Solid-Phase Extraction Based on Decanoic Acid Coated-Fe3 O4 Nanoparticles for HPLC Analysis of Phthalate Esters in Liquor Samples.

    Science.gov (United States)

    Wang, Juan; Zhang, Lei; Xin, Dingqiang; Yang, Yaling

    2015-11-01

    A novel, simple and low cost through coating Fe3 O4 magnetic nanoparticles (MNPs) with decanoic acid were synthesized. The functionalized MNPs showed excellent dispersibility in aqueous solution and were applied to dispersive micro-solid-phase extraction (D-?-SPE) followed by high performance liquid chromatographic analysis for 4 phthalate esters (PAEs) including benzyl butyl phthalate (BBP), dicyclohexyl phthalate (DCHP), di-n-butyl phthalate (DBP), and di-n-octyl phthalate (DNOP) from liquor samples. The extraction equilibrium is achieved in 1 min. The MNPs allow easy and rapid isolation of PAEs by using an external magnet, which can be reused 5 times. The 4 PAEs linear dynamic ranges were in the range of 5 to 1000 ng/mL and the correlation coefficients values were 0.9999. The limits of detection were in the range of 0.91 to 2.43 ng/mL. The influences of the adsorbent dosage and the use frequency of adsorbent, the adsorption time, the solution pH and ionic strength were investigated and optimized. The proposed method was used to determine of PAEs in liquor samples and recoveries between 88.9% and 105.4%, with the relative standard deviations were below 4.0%. PMID:26447907

  19. Solid phase extraction and enrichment of essential fatty acid methyl esters from soy-derived biodiesel by novel pi-complexing sorbents.

    Science.gov (United States)

    Li, Min; Pham, Patrisha J; Wang, Tao; Pittman, Charles U; Li, Tingyu

    2009-12-01

    The essential fatty acid (EFA) methyl esters, methyl linolenate (18:3) and methyl linoleate (18:2), were extracted and enriched from soy-derived biodiesel using novel pi-complexing sorbents. These pi-complexing sorbents were prepared by covalently immobilizing ionic liquids (ILs) onto silica and then coating these silica-supported ILs with silver salts. The silica-supported hydrophobic ILs enhanced the retention of silver salts on the solid sorbents. After the extraction of the polyunsaturated fatty acid methyl esters (PUFAMEs) 18:3 and 18:2 from biodiesel using the sorbents, a decrease in NO(x) emissions and an enhancement of the oxidation stability of biodiesel can be obtained. Solid phase extraction was investigated using a simple three-step procedure consisting of (1) sorbent pre-treatment, (2) sample extraction onto the sorbent and (3) stripping the sorbent by desorption solvent. The factors influencing extraction capacity and selectivity were also studied. 10.5 Mg of sorbent AgBF(4)/SiO(2) x Im(+) x PF(6)(-) could completely adsorb the 18:3 (0.66 mg) from standard biodiesel hexane solution in 5 min. After a consecutive two-step stripping by diethyl ether and 1-hexene, the 18:3 concentration (wt.%) was increased from around 8.5% in the original biodiesel hexane solution to approximately 90% in the 1-hexene stripping solvent. PMID:19692237

  20. Rapid determination of cyclamate in foods by solid-phase extraction and capillary electrophoresis.

    Science.gov (United States)

    Horie, Masao; Ishikawa, Fusako; Oishi, Mitsuo; Shindo, Tetsuya; Yasui, Akiko; Ito, Koichi

    2007-06-22

    A method for the determination of cyclamate in food was developed using solid-phase extraction (SPE) and capillary electrophoresis (CE) with indirect ultraviolet (UV) detection. A 5-10 g sample in 0.1 mol/L hydrochloric acid was homogenized and made up to a volume of 50 mL with 0.1 mol/L hydrochloric acid. After the sample was centrifuged, 25 mL of supernatant was loaded into an Oasis HLB SPE cartridge. The cartridge was washed with 2 mL of demineralized water followed by 2 mL of 50% aqueous methanol, and cyclamate was eluted with 4.5 mL of 50% aqueous methanol. The eluate was added to a solution of sodium propionate (internal standard) for CE analysis. The cyclamate in the eluate was electrophoresed on a fused-silica capillary using 1 mmol/L hexadecyltrimethylammonium bromide and 10 mmol/L potassium sorbate as a running buffer. Detection and reference wavelengths of cyclamate determined with a UV detector were 300 and 254 nm, respectively. The calibration curves for cyclamate showed good linearity in the range of 2-1000 microg/mL and the limits of detection in beverage, fruit in syrup, jam, pickles and confectionary are sample dependent and ranged from 5-10 microg/g. The recovery of cyclamate added at a level of 200 microg/g to various kinds of foods was 93.3-108.3% and the relative standard deviation was less than 4.9% (n=3). A number of commercial samples were analyzed using the proposed method. Cyclamate was detected in one waume, two pickles, and two sunflower seeds. The quantitative values determined with CE correlated to those from high-performance liquid chromatography (HPLC) (the detected values of cyclamate in a sunflower seed measured by CE and HPLC were 3.40 g/kg and 3.51 g/kg, respectively). This analytical method for cyclamate using CE is especially suitable for use in the field. PMID:17433340

  1. Characterization of large surface area polymer monoliths and their utility for rapid, selective solid phase extraction for improved sample clean up.

    Science.gov (United States)

    Candish, Esme; Wirth, Hans-Jürgen; Gooley, Andrew A; Shellie, Robert A; Hilder, Emily F

    2015-09-01

    While polymer monoliths are widely described for solid phase extraction (SPE), appropriate characterization is rarely provided to unravel the links between physical characteristics and observed advantages and disadvantages. Two known approaches to fabricate large surface area polymer monoliths with a bimodal pore structure were investigated. The first incorporated a high percentage of divinyl benzene (PDVB) and the second explored hypercrosslinking of pre-formed monoliths. Adsorption of probe analytes; anisole, benzoic acid, cinnamic acid, ibuprofen and cortisone were investigated using frontal analysis and the SPE performance was compared with particulate adsorbents. Frontal analysis of anisole described maximum adsorption capacities of 164mgg(-1) and 298mgg(-1) for hypercrosslinked and PDVB adsorbents, respectively. The solvated state specific surface area was calculated to be 341 and 518m(2)g(-1) respectively. BET revealed a hypercrosslinked surface area of 817m(2)g(-1), 2.5 times greater than in the solvated state. The PDVB BET surface area was 531m(2)g(-1), similar to the solvated state. Micropores of 1nm provided the enhanced surface area for hypercrosslinked adsorbents. PDVB displayed a pore size distribution of 1-6nm. Frontal analysis demonstrated the micropores present size exclusion for the larger probes. Recovery of anisole was determined by SPE using 0.4 and 1.0mLmin(-1). Recovery for PDVB remained constant at 90%±0.103 regardless of the extraction flow rate suggesting extraction performance is independent of flow rate. A more efficient sample purification of saccharin in urine was yielded by PDVB due to selective permeation of the small pores. PMID:26233256

  2. Synthesis and Evaluation of a Molecularly Imprinted Polymer for Selective Solid-Phase Extraction of Irinotecan from Human Serum Samples

    Directory of Open Access Journals (Sweden)

    Isabelle Lefebvre-Tournier

    2012-02-01

    Full Text Available A molecularly imprinted polymer (MIP was synthesized by non-covalent imprinting polymerization using irinotecan as template. Methacrylic acid and 4-vinylpyridine were selected as functional monomers. An optimized procedure coupled to LC-PDA analysis was developed for the selective solid-phase extraction of irinotecan from various organic media. A specific capacity of 0.65 µmol•g?1 for the MIP was determined. The high specificity of this MIP was demonstrated by studying the retention behaviour of two related compounds, camptothecin and SN-38. This support was applied for the extraction of irinotecan from human serum samples.

  3. Solid-phase extraction on C18 in the trace determination of selected polychlorinated biphenyls in milk.

    Science.gov (United States)

    Picó, Y; Redondo, M J; Font, G; Mañes, J

    1995-02-24

    The utility of solid-phase extraction with octadecylsilica for determining fifteen polychlorinated biphenyl (PCB) congeners from milk samples was examined. Recoveries higher than 80% and relative standard deviations better than 10% were obtained for PCBs from different kinds of milk (whole, skimmed, 2%, powdered, breast and evaporated). A comparison with other procedures was made. The described method provides better detection limits than those attainable with the liquid-liquid extractions currently used as standard methods, when capillary gas-liquid chromatography is used for the final determination. A study of the separation was also performed using six different fused-silica capillary columns and an electron-capture detector. PMID:7704189

  4. Characteristic of New Solid-Phase Extraction Sorbent: Activated Carbon Prepared from Rice Husks under Base Treated Condition

    OpenAIRE

    Afrida Kurnia Putri; Wang-Hsien Ding; Han-Wen Kuo

    2012-01-01

    A characterization of activated carbon (ACs) prepared from rice husks (RHs) under base treated condition as a new sorbent for solid-phase extraction (SPE) to extract 4-nonylphenol isomers (4-NPs) in water samples has been done. The ACs prepared from RHs usually exhibits low specific surface area due to its high ash content, but in case of its application for SPE, there are other factors need to be considered, such as the existence of functional groups inside the sorbent, that can enhance inte...

  5. Optimization of pressurized liquid extraction using a multivariate chemometric approach and comparison of solid phase extraction cleanup steps for the determination of polycyclic aromatic hydrocarbons in mosses

    OpenAIRE

    Foan, Louise; Simon, Valérie

    2012-01-01

    A factorial design was used to optimize the extraction of polycyclic aromatic hydrocarbons (PAHs) from mosses, plants used as biomonitors of air pollution. The analytical procedure consists of pressurized liquid extraction (PLE) followed by solid-phase extraction (SPE) cleanup, in association with analysis by high performance liquid chromatography coupled with fluorescence detection (HPLC-FLD). For method development, homogeneous samples were prepared with large quantities of the mosses Isoth...

  6. Selective extraction of phospholipids from dairy products by micro-solid phase extraction based on titanium dioxide microcolumns followed by MALDI-TOF-MS analysis

    DEFF Research Database (Denmark)

    Calvano, Cosima; Jensen, Ole; Zambonin, Carlo

    2009-01-01

    A new micro-solid phase extraction (micro-SPE) procedure based on titanium dioxide microcolumns was developed for the selective extraction of phospholipids (PLs) from dairy products before matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analysis. All the extraction steps (loading, washing, and elution) have been optimized using a synthetic mixture of PLs standard and the procedure was subsequently applied to food samples such as milk, chocolate milk an...

  7. Mixed hemimicelles solid-phase extraction based on sodium dodecyl sulfate (SDS)-coated nano-magnets for the spectrophotometric determination of Fingolomid in biological fluids.

    Science.gov (United States)

    Azari, Zhila; Pourbasheer, Eslam; Beheshti, Abolghasem

    2016-01-15

    In this study, mixed hemimicelles solid-phase extraction (SPE) based on sodium dodecyl sulfate (SDS)-coated nano-magnets Fe3O4 was investigated as a novel method for the separation and determination of Fingolimod (FLM) in water, urine and plasma samples prior to spectrophotometeric determination. Due to the high surface area of these new sorbents and the excellent adsorption capacity after surface modification by SDS, satisfactory extraction recoveries can be produced. The main factors affecting the adsolubilization of analysts, such as pH, surfactant and adsorbent amounts, ionic strength, extraction time and desorption conditions were studied and optimized. Under the selected conditions, FLM has been quantitatively extracted. The accuracy of the method was evaluated by recovery measurements on spiked samples, and good recoveries of 96%, 95% and 88% were observed for water, urine and plasma respectively. Proper linear behaviors over the investigated concentration ranges of 2-26, 2-17 and 2-13mg/L with good coefficients of determination, 0.998, 0.997 and 0.995 were achieved for water, urine and plasma samples, respectively. To the best of our knowledge, this is the first time that a mixed hemimicelles SPE method based on magnetic separation and nanoparticles has been used as a simple and sensitive method for monitoring of FLM in water and biological samples. PMID:26439525

  8. 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)

    Science.gov (United States)

    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.

  9. Correction: An integrated slidable and valveless microdevice with solid phase extraction, polymerase chain reaction, and immunochromatographic strip parts for multiplex colorimetric pathogen detection.

    Science.gov (United States)

    Kim, Yong Tae; Lee, Dohwan; Heo, Hyun Young; Kim, Do Hyun; Seo, Tae Seok

    2015-12-01

    Correction for 'An integrated slidable and valveless microdevice with solid phase extraction, polymerase chain reaction, and immunochromatographic strip parts for multiplex colorimetric pathogen detection' by Yong Tae Kim et al., Lab Chip, 2015, 15, 4148-4155. PMID:26502177

  10. Matrix solid-phase dispersion extraction and quantification of alpinetin in amomum seed using validated HPLC and HPTLC methods

    Directory of Open Access Journals (Sweden)

    M Singh

    2015-01-01

    Full Text Available 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 (60F 254 using toluene, dichloromethane and ethyl acetate as solvent system. A sharp peak was obtained for alpinetin at a retention time (R t of 5.7 min by HPLC and retardation factor (R f 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.

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

    Science.gov (United States)

    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

  12. Extraction of Pb2+ using Silica from Rice Husks Ash (RHA) – Chitosan as Solid Phase

    OpenAIRE

    Hanandayu Widwiastuti; Ani Mulyasuryani; Akhmad Sabarudin

    2013-01-01

    The existence of lead (Pb) compounds in waters can be caused of waste pollution from industrial activities such as dye and battery industries. Lead has toxic characteristic and is able to causing deseases. The levels of Cr(VI) can be decreased by methods such as electroplating, oxidation, reduction, and membrane separation. But this methods require high cost and produce a lot of waste. Furthermore, those methods cannot determine the small concentration of Pb2+. Therefore, solid phase extracti...

  13. Extração em fase sólida (SPE e micro extração em fase sólida (SPME de piretróides em água Solid-phase extraction (SPE and solid-phase microextraction of pyrethroids in water

    Directory of Open Access Journals (Sweden)

    Wilma Regina Barrionuevo

    2001-04-01

    Full Text Available The pyrethroids bifenthrin, permethrin, cypermethrin and deltamethrin were extracted by solid phase extraction (SPE and solid phase microextraction (SPME. The analysis were performed on a gas chromatograph with electron capture detection (GC-ECD. Octadecil Silano-C18, Florisil and Silica stationary phases were studied for SPE. Better results were obtained for Florisil which gave recoveries from 80% to 108%. Pyrethroids extraction by SPME showed a linear response and a detection limit of 10 pg ml-1. Although the data showed that the two extraction methods were able to isolate the pesticide residues from water samples, the best results were obtained by using SPME which is more sensitive, faster, cheeper, being a more useful technique for the analysis of pyrethroids in drinking water.

  14. Extração em fase sólida (SPE) e micro extração em fase sólida (SPME) de piretróides em água / Solid-phase extraction (SPE) and solid-phase microextraction of pyrethroids in water

    Scientific Electronic Library Online (English)

    Wilma Regina, Barrionuevo; Fernando Mauro, Lanças.

    2001-04-01

    Full Text Available [...] Abstract in english The pyrethroids bifenthrin, permethrin, cypermethrin and deltamethrin were extracted by solid phase extraction (SPE) and solid phase microextraction (SPME). The analysis were performed on a gas chromatograph with electron capture detection (GC-ECD). Octadecil Silano-C18, Florisil and Silica stationa [...] ry phases were studied for SPE. Better results were obtained for Florisil which gave recoveries from 80% to 108%. Pyrethroids extraction by SPME showed a linear response and a detection limit of 10 pg ml-1. Although the data showed that the two extraction methods were able to isolate the pesticide residues from water samples, the best results were obtained by using SPME which is more sensitive, faster, cheeper, being a more useful technique for the analysis of pyrethroids in drinking water.

  15. Spectrophotometric Determination of Aluminium in Iron Ores Using Solid-Phase Extraction

    Scientific Electronic Library Online (English)

    Sérgio Luis Costa, Ferreira; Valfredo Azevedo, Lemos; Antônio Celso Spinola, Costa; Djane Santiago de, Jesus; Marcelo Souza de, Carvalho.

    1998-04-01

    Full Text Available No presente trabalho, um procedimento para separação e determinação de alumínio em matrizes de ferro é proposto. Este é baseado na extração em fase sólida do ferro sob a forma de tiocianatos complexos, pela espuma de poliuretano. Os seguintes parâmetros foram estudados: efeito de pH e da concentraçã [...] o de tiocianato sob a extração do ferro, tempo de agitação necessário para extração quantitativa, quantidade de espuma requerida, separação de alumínio de ferro e de outros elementos, influência de ânions sob a sorção de ferro pela espuma e características analíticas do procedimento para determinação de alumínio usando o azul de metiltimol (MTB) como reagente cromogênico. Os resultados demonstraram que na faixa de pH de 1,5 a 4,7, com tiocianato na concentração de 0.80 mol L-1, tempo de agitação de 1 min e usando 1 g de espuma de poliuretano para extração, é possível separar alumínio(40 mig) de: grandes quantidades de ferro (10 mg), 800 mig de cobre(II), cobalto(II), zinco(II), mercúrio(II), manganês(II), estanho(IV) e tungstênio(V); 100 mig de chumbo(II) e titânio(IV) e 50 mig de vanádio(V). Cálcio(II), bário(II), estrôncio(II) e magnésio(II) não são separados por este processo; entretanto, não reagem com o MTB nas condições estabelecidas para determinação de alumínio. Os ânions nitrato, cloreto, sulfato e acetato não afetam a extração do ferro. Fosfato e EDTA devem estar ausentes. O azul de metiltimol possibilita a determinação espectrofotométrica de alumínio, com absortividade molar de 1,32 x 10(4) L mol-1 cm-1(em 528 nm), sensibilidade de calibração de 0,491 mL mig-1, limite de detecção de 5 ng mL-1, intervalo dinâmico de aplicação de 15 ng mL-1 a 1,00 mig mL-1 e coeficiente de variação de 0,73%. O procedimento proposto foi aplicado para determinação de alumínio em padrões de minérios de ferro e ligas metálicas. Os resultados encontrados não exibiram diferenças significativas em relação aos valores certificados. Abstract in english In the present paper, a procedure for separation and determination of aluminium in iron matrices is proposed. It is based on the solid-phase extraction of the iron, in the form of thiocyanate complexes, by a polyurethane(PU) foam. The followings parameters were studied: effect of pH and of the thioc [...] yanate concentration on the iron extraction, shaking time required for quantitative extraction, amount of PU foam necessary for complete extraction of iron, aluminium separation from other cations, influence of anions on the iron sorption by PU foam and analytical characteristics of the procedure for aluminium determination using methylthymol blue as chromogenic reagent. The results show that, in the pH range from 1.5 to 4.7, with a thiocyanate concentration of 0.80 mol L-1, by extraction using 1 g of polyurethane foam and a shaking time of 1 min, aluminium (40 mug) can be separated from large amounts of iron (10 mg), 800 mug of copper(II), cobalt(II), zinc(II), mercury(II), tin(IV), manganese(II) and tungsten(V); 100 mug of titanium(IV) and lead(II); and 50 mug of vanadium(V). Calcium(II), barium(II), strontium(II) and magnesium(II) can not be separated by this process, but do not react with MTB under the conditions used for aluminium determination. The anions nitrate, chloride, sulfate and acetate do not affect the iron extraction. Phosphate and EDTA must be absent. The methylthymol blue allowed the spectrophotometric determination of aluminium with molar absorptivity of 1.32 x 10(4) L mol-1 cm-1 (528 nm), calibration sensitivity of 0.491 mL g-1, detection limit of 5 ng mL-1 and dynamic interval of application of 15 ng mL-1 to 1.00 mg mL-1 and variation coefficient of 0.73%. The proposed procedure was applied for aluminium determination in iron ores and metal-base alloy standards. The obtained results did not show significant difference from the certified values.

  16. One-step synthesis of magnetic graphene oxide nanocomposite and its application in magnetic solid phase extraction of heavy metal ions from biological samples.

    Science.gov (United States)

    Sun, Jieping; Liang, Qionglin; Han, Qiang; Zhang, Xiaoqiong; Ding, Mingyu

    2015-01-01

    A novel magnetic graphene oxide nanocomposite was synthesized by one-step coprecipitation method and characterized by transmission electron microscopy, X-ray photoelectron spectroscopy and vibrating sample magnetometer. The nanocomposite beard many intriguing properties, including chemical stability, high adsorption capacity, and superparamagnetic. These properties evoked great interest and desire of its exploration in magnetic solid-phase extraction of heavy metal ions from complex samples. Several parameters effecting the analytical performance, such as the sample pH, amounts of adsorbent, sample volumes, elution volumes, and coexisting ions, had been investigated in detail. The adsorbed metal ions were easy eluted by controlling the pH condition and the materials could be reused more than 20 times. Under the optimized conditions, the limits of detection were 0.016, 0.046, 0.395, 0.038, 0.157 ?g L(-1) for Co(2+), Ni(2+), Cu(2+), Cd(2+), and Pb(2+), respectively. The intra-day relative standard deviations (n=5) were in the range of 1.8-5.5% at 10 ?g L(-1). The proposed method was successfully applied to biological sample analysis and got excellent recoveries in the range of 81-113% even the matrix was complex. PMID:25476344

  17. Application of tandem column solid phase extraction and flame atomic absorption spectrometry for the determination of inorganic and organically bound forms of iron in wine.

    Science.gov (United States)

    Pohl, Pawel; Prusisz, Bartlomiej

    2009-03-15

    A tandem column solid phase extraction (SPE) procedure has been devised to examine the fractionation of Fe in wine. Wine was filtered through a 0.45 microm filter and then, the filtrate was driven through an adsorbing Amberlite XAD-7HP column followed by a cation exchange Dowex 50 W-x8-200 column. Three different Fe groupings are discriminated and assessed, including hydrophobic species of Fe bound to phenolic substances and related species (phenolic fraction), cationic species comprising simple Fe ions and labile Fe forms (cationic fraction), in addition to anionic and/or neutral Fe complexes with organic acids (residual fraction). The suitability of the procedure has been evaluated analyzing four bottled red wines. The results obtained were verified using another tandem column assemblage in which an adsorbing Amberlite XAD-16 column was exchanged by the Amberlite XAD-7HP column. The fractionation pattern ascertained for Fe in analyzed wines is discussed in reference to previously published works. In addition, a conditioning treatment and preparation of Amberlite XAD resins have been revised. PMID:19159790

  18. POLYELECTROLYTE MODIFIED SILICA GEL MICRO-COLUMN SOLID PHASE EXTRACTION FOR THE DETERMINATION OF SILVER IN ENVIRONMENTAL WATER SAMPLES BY FLAME ATOMIC ABSORPTION SPECTROMETRY

    Scientific Electronic Library Online (English)

    GUOQIANG, XIANG; LULU, LI; XIUMING, JIANG; LIJUN, HE; LU, FAN.

    2013-12-01

    Full Text Available Silica gel was chemically modified with polyelectrolyte and used as a solid phase extraction adsorbent for the determination of trace silver in environmental water samples by flame absorption spectrometry (FAAS). The effects of pH, sample flow rate and volume, elution conditions and co-existing ions [...] on the recovery of the analyte were investigated. The results showed that silver could be adsorbed at pH 5.0 and eluted by 5.0 mL 2% thiourea in HNO3 (0.1 mol L-1). Under the optimized conditions, the adsorption capacity of modified silica gel was found to be 8.6 mg g-1 for silver. The detection limit of the proposed method was 1.0 ng mL-1 for silver with an enrichment factor of 18.7. The analytical result for the certified reference water sample (GBW08610) was in a good agreement with the certified value. The proposed method has also been successfully applied to the determination of trace silver in drinking water, well water, snow water and waste water with the recoveries for spiked samples between 94% and 105%.

  19. Zeolite/Fe3 O4 as a new sorbent in magnetic solid-phase extraction followed by gas chromatography for determining phthalates in aqueous samples.

    Science.gov (United States)

    Mollahosseini, Afsaneh; Toghroli, Mina; Kamankesh, Marzieh

    2015-11-01

    In the present study, for the first time, we successfully employed zeolite/Fe3 O4 as a new magnetic nanoparticle sorbent in magnetic solid-phase extraction for determining phthalates in aqueous samples. Gas chromatography with flame ionization detection was used to detect the target analytes as a powerful instrumental analysis. Affecting parameters in the extraction process, including the amount of adsorbent, adsorption and desorption time, and volume of desorption solvent, were optimized using a response surface methodology based on central composite design. Under the optimum conditions, the linear range for dibutyl phthalate and bis(2-ethylhexyl phthalate) was varied in the interval of 10-1700 and 10-1200 ?g/L, respectively. Limits of detection were 2.80 ?g/L for dibutyl phthalate and 3.20 ?g/L for bis(2-ethylhexyl phthalate). The recovery value for the extraction of target analytes was between 97 and 111%. The repeatability and reproducibility of the new proposed method were obtained: 10-13% and 13-13.5%, respectively. The increased sensitivity in using the proposed method has been demonstrated. Compared with previous methods, the new proposed method is an accurate, rapid, and reliable sample-pretreatment method. PMID:26333673

  20. Highly sensitive determination of sulfonamides in environmental water samples by sodium dodecylbenzene sulfonate enhanced micro-solid phase extraction combined with high performance liquid chromatography.

    Science.gov (United States)

    Zhou, Qingxiang; Fang, Zhi

    2015-08-15

    Sulfonamides are important antibiotics, and have achieved great applications. However they also impose serious threat on the environment and human health when they enter into environment by various ways. Present study developed a new determination method for six sulfonamides such as sulfadiazine, sulfamerazine, sulfamethazine, sulfadimethoxine, sulfamethoxazole and sulfafurazole in water samples, which was based on micro-solid phase extraction (?-SPE) using TiO2 nanotube arrays as the adsorbent in combination with high performance liquid chromatography. Surfactant sodium dodecylbenzene sulfonate (SDBS) was used to enhance the extraction performance in this enrichment procedure. The parameters that affected the extraction efficiency had been investigated. Under the optimal conditions, it was observed that there were good linear relationships between the peak areas and the concentrations of the sulfonamides. The linear ranges were 1-200?g L(-1) for the six sulfonamides with the correlation coefficients in the range of 0.998-0.999. The repeatability of the proposed method was satisfactory in the range of 2.1-4.4% (RSD, n=6). The limits of detection (LODs) were in the range of 0.27-0.6?g L(-1). The proposed method was validated with real environmental samples, and the spiked recoveries were satisfied. These results indicated that the proposed method was a good tool for monitoring sulfonamides in the water samples. PMID:25966398

  1. A Rapid LC-HRMS Method for the Determination of Domoic Acid in Urine Using a Self-Assembly Pipette Tip Solid-Phase Extraction

    Directory of Open Access Journals (Sweden)

    Yiping Zhang

    2015-12-01

    Full Text Available In this study, we developed a self-assembly pipette tip solid-phase extraction (PTSPE method using a high molecular weight polymer material (PAX as the adsorbent for the determination of domoic acid (DA in human urine samples by liquid chromatography high-resolution mass spectrometry (LC-HRMS analysis. The PTSPE cartridge, assembled by packing 9.1 mg of PAX as sorbent into a 200 ?L pipette tip, showed high adsorption capacity for DA owing to the strong cationic properties of PAX. Compared with conventional SPE, the PTSPE is simple and fast, and shows some advantages in the aspects of less solvent consumption, low cost, the absence of the evaporation step, and short time requirement. All the parameters influencing the extraction efficiency such as pH, the amount of sorbent, the number of aspirating/dispensing cycles, and the type and volume of eluent in PTSPE were carefully investigated and optimized. Under the optimized conditions, the limit of detection (LOD and limit of quantification (LOQ values of DA were 0.12 ?g/L and 0.37 ?g/L respectively. The extraction recoveries of DA from the urine samples spiked at four different concentrations were in a range from 88.4% to 102.5%. The intra- and inter-day precisions varied from 2.1% to 7.6% and from 2.6% to 12.7%, respectively. The accuracy ranged from ?1.9% to ?7.4%.

  2. Solid phase extraction and a spectrophotometric method for the determination of trace amounts of gold with 4-rhodanineazo benzoic acid

    OpenAIRE

    ZHANG JIE HUANG; XIAO GUO WANG; JUN ZHANG

    2009-01-01

    The synthesis and application of 4-rhodanineazo benzoic acid (4-BARA) as a new chromogenic reagent for the determination of gold is des¬cribed. A highly sensitive, selective, and fast method for the determination of gold based on its rapid reaction with 4-rhodanineazo benzoic acid and the solid phase extraction of the colored complex on a reversed phase Clean-up® C5 cartridge was developed. In the presence of 0.02–0.2 mol/L phosphoric acid solution and a polyoxyethylene nonylphenol ether (emu...

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

    DEFF Research Database (Denmark)

    Fromberg, Arvid; Højgård, A.; Duedahl-Olesen, Lene

    2007-01-01

    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 fo...

  4. Simple purification of recovered [18O]H2O by UV, ozone, and solid-phase extraction methods

    International Nuclear Information System (INIS)

    We have developed three methods for removing organic impurities as well as a solid-phase extraction (SPE) method for removing metallic and ionic impurities from recovered [18O]H2O. Preliminary experiments with [16O]H2O were used to determine the optimal purification conditions. These showed that UV irradiation rapidly (18O]H2O removed all organic and inorganic impurities. The purified [18O]H2O gave a saturation yield of 128.62±15.6 mCi/?A for [18F]fluoride and a 49.8±12.7% radiochemical yield for [18F]fluorodeoxyglucose

  5. A combination of solid-phase extraction and dispersive solid-phase extraction effectively reduces the matrix interference in liquid chromatography-ultraviolet detection during pyraclostrobin analysis in perilla leaves.

    Science.gov (United States)

    Farha, Waziha; Rahman, Md Musfiqur; Abd El-Aty, A M; Jung, Da-I; Kabir, Md Humayun; Choi, Jeong-Heui; Kim, Sung-Woo; Jeong Im, So; Lee, Young-Jun; Shin, Ho-Chul; Kwon, Chan-Hyeok; Son, Young-Wook; Lee, Kang-Bong; Shim, Jae-Han

    2015-12-01

    Perilla leaves contain many interfering substances; thus, it is difficult to protect the analytes during identification and integration. Furthermore, increasing the amount of sample to lower the detection limit worsens the situation. To overcome this problem, we established a new method using a combination of solid-phase extraction and dispersive solid-phase extraction to analyze pyraclostrobin in perilla leaves by liquid chromatography with ultraviolet absorbance detection. The target compound was quantitated by external calibration with a good determination coefficient (R(2) = 0.997). The method was validated (in triplicate) with three fortification levels, and 79.06- 89.10% of the target compound was recovered with a relative standard deviation <4. The limits of detection and quantification were 0.0033 and 0.01 mg/kg, respectively. The method was successfully applied to field samples collected from two different areas at Gwangju and Muan. The decline in the resiudue concentrations was best ascribed to a first-order kinetic model with half-lives of 5.7 and 4.6 days. The variation between the patterns was attributed to humidity. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26032066

  6. Graphene-based solid-phase extraction combined with flame atomic absorption spectrometry for a sensitive determination of trace amounts of lead in environmental water and vegetable samples

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yukun; Gao Shutao; Zang Xiaohuan [Hebei Key Laboratory of Bioinorganic Chemistry, College of Sciences, Agricultural University of Hebei, Baoding 071001 (China); Li Jingci, E-mail: jingcili63@yahoo.com.cn [Hebei Key Laboratory of Bioinorganic Chemistry, College of Sciences, Agricultural University of Hebei, Baoding 071001 (China); Ma Jingjun, E-mail: majingjun@hebau.edu.cn [Hebei Key Laboratory of Bioinorganic Chemistry, College of Sciences, Agricultural University of Hebei, Baoding 071001 (China)

    2012-02-24

    Highlights: Black-Right-Pointing-Pointer Graphene as a novel sorbent material in a column for solid-phase extraction (SPE). Black-Right-Pointing-Pointer SPE for the determination of lead (Pb) in environment water samples and vegetable samples. Black-Right-Pointing-Pointer The system can be reused for many times. Black-Right-Pointing-Pointer The adsorption capacity of graphene over many other adsorbents. Black-Right-Pointing-Pointer Graphene has great potentials as an excellent sorbent material. - Abstract: Graphene, a novel class of carbon nanostructures, has great promise for use as sorbent materials because of its ultrahigh specific surface area. A new method using a column packed with graphene as sorbent was developed for the preconcentration of trace amounts of lead (Pb) using dithizone as chelating reagent prior to its determination by flame atomic absorption spectrometry. Some effective parameters on the extraction and complex formation were selected and optimized. Under optimum conditions, the calibration graph was linear in the concentration range of 10.0-600.0 {mu}g L{sup -1} with a detection limit of 0.61 {mu}g L{sup -1}. The relative standard deviation for ten replicate measurements of 20.0 and 400.0 {mu}g L{sup -1} of Pb were 3.56 and 3.25%, respectively. Comparative studies showed that graphene is superior to other adsorbents including C18 silica, graphitic carbon, and single- and multi-walled carbon nanotubes for the extraction of Pb. The proposed method was successfully applied in the analysis of environmental water and vegetable samples. Good spiked recoveries over the range of 95.3-100.4% were obtained. This work not only proposes a useful method for sample preconcentration, but also reveals the great potential of graphene as an excellent sorbent material in analytical processes.

  7. Solid-phase extraction and cleanup of organophosphorus pesticide residues in bovine muscle with gas chromatographic detection.

    Science.gov (United States)

    Kuivinen, Jorma; Bengtsson, Staffan

    2002-08-01

    The purpose of this investigation is to develop a rapid and simple method for the assessment of organophosphorus pesticides in bovine muscle by using solid-phase extraction (SPE). After extraction with ethyl acetate (EtOAc) the homogenate is centrifuged and filtered through sodium sulfate. The fat is precipitated in methanol by cooling and the extract is diluted with water and passed through a SPE column (Isolute ENV+). After elution with EtOAc, evaporation, and redissolution, the sample is injected into a gas chromatographic (GC) capillary column DB-1701 and detected by a flame photometric detector. Recoveries from bovine muscle fortified with 12 pesticides between 4 and 65 microg/kg include three levels ranging between 59% and 109% for ten of them. The two most polar pesticides (metamidophos and acephate) are not successful. The relative standard deviations are between 1% and 10% for the ten pesticides. A simplex method is used to optimize the GC conditions. PMID:12201481

  8. Flame atomic absorption spectrometric (FAAS) determination of copper, iron and zinc in food samples after solid-phase extraction on Schiff base-modified duolite XAD 761

    International Nuclear Information System (INIS)

    The present study involves the development of solid-phase extraction (SPE) procedure for the preconcentration of trace amounts of copper (Cu2+), iron (Fe3+) and zinc (Zn2+) ions on duolite XAD 761 modified by bis(2-hydroxyacetophenone)-2,2-dimethyl-1,3-propanediimine(BHAPDMPDI). The complexation between the metal ions and the proposed ligand was investigated potentiometrically. The metal ions retained on the sorbent were quantitatively determined via complexation with BHAPDMPDI. The complexed metal ions were efficiently eluted using 6 mL of 4 mol L?1 nitric acid in acetone. The influences of the analytical parameters, including pH, amounts of the ligand and the solid phase, eluent conditions and sample volume, on the recoveries of the metal ions were optimized. Using the optimized parameters, the linear response of the SPE method for Cu2+, Zn2+ and Fe3+ ions were in the ranges of 0.01–0.34, 0.01–0.28 and 0.02–0.31 ?g mL?1, respectively, and the detection limits for Cu2+, Zn2+ and Fe3+ ions were 1.8, 1.6 and 2.4 ?g mL?1, respectively. The proposed method exhibits a preconcentration factor of 208 for all of the ions studied and an enhancement factor for Cu2+, Fe3+ and Zn2+ ions of 34, 28 and 38, respectively. The presented results demonstrate the successful application of the proposed method for the determination of these metal ions in some real samples with high recoveries (> 95%) and reasonable relative standard deviation (RDS < 5%). Highlights: ? Highly efficient adsorbent for dye removal was synthesized. ? The sorbent was fully characterized. ? The proposed method has a potential of a waste water treatment alternative. ? Excellent properties of the sorbent have been illustrated in detail

  9. Solid phase extraction and a spectrophotometric method for the determination of trace amounts of gold with 4-rhodanineazo benzoic acid

    Directory of Open Access Journals (Sweden)

    ZHANG JIE HUANG

    2009-09-01

    Full Text Available The synthesis and application of 4-rhodanineazo benzoic acid (4-BARA as a new chromogenic reagent for the determination of gold is des¬cribed. A highly sensitive, selective, and fast method for the determination of gold based on its rapid reaction with 4-rhodanineazo benzoic acid and the solid phase extraction of the colored complex on a reversed phase Clean-up® C5 cartridge was developed. In the presence of 0.02–0.2 mol/L phosphoric acid solution and a polyoxyethylene nonylphenol ether (emulsifier-OP medium, 4-rhodanineazo benzoic acid reacted with gold to form a colored complex with a gold-to-4-BARA molar ratio of 1:2. The complex was enriched by solid phase extraction with a reversed phase Clean-up® C5 cartridge. The complex was eluted from the cartridge with ethanol and an enrichment factor of 50 was achieved. In ethanol medium, the molar absorptivity of the complex was 2.39×105 L mol-1 cm-1 at 505 nm. The Beer Law was obeyed in the concentration range 0.01–?1.2 µg/mL. The relative standard deviation for eleven replicate samples at the 0.001 µg/mL level was 2.3 %. In the original sample, the detection limit was 8.0×10-5 µg/mL. This method was applied to the determination of trace amounts of gold in ore samples with good result.

  10. Solid phase extractive preconcentration of uranium(VI) using quinoline-8-ol anchored chloromethylated polymeric resin beads.

    Science.gov (United States)

    Praveen, R S; Metilda, P; Daniel, S; Rao, T Prasada

    2005-10-31

    A new chelating polymeric sorbent has been developed using Merrifield chloromethylated resin anchored with quinoline-8-ol (HQ). The modified polymeric resin was characterized by FT-IR spectroscopy and elemental analysis. The HQ anchored resin showed superior binding affinity for U(VI) over Th(IV) and La(III). The influence of various physicochemical parameters on the recovery of U(VI) were optimized by both static and dynamic methods. The phase exchange kinetic studies performed for U(VI) revealed that ion sorption. The maximum sorption capacity of HQ anchored resin for U(VI) was found to be 120.30mgg(-1) of resin which is higher than other solid phase extraction sorbents reported so far excepting N,N-dibutyl, N'-benzoyl thiourea sorbed Amberlite XAD-16. The developed HQ anchored polymeric resin is highly selective as none of the extraneous species were found to have any deleterious effect. Solid phase extraction (SPE) studies performed using HQ anchored polymeric resin offered enrichment factor of 100 and the lowest concentration below which recoveries become non-quantitative is 5mugl(-1). The accuracy of the developed SPE method in conjunction with Arsenazo III procedure was tested by analyzing marine sediment (MESS-3) and soil (IAEA-Soil 7) reference materials. Furthermore, the above procedure has been successfully employed for the analysis of real soil and sediment samples. PMID:18970265

  11. Solid phase extraction and spectrophotometric determination of mercury in tobacco and tobacco additives with 5-(p-aminobenzylidene)-thiothiorhodanine

    International Nuclear Information System (INIS)

    A highly sensitive, selective and rapid method for the determination of mercury based on the rapid reaction of mercury(II) with 5-(p-aminobenzylidene)-thiorhodanine (ABTR) and the solid phase extraction of the colored chelate with C18 disks has been developed. At pH 3.5 and in the presence of emulsifier-OP medium, ABTR reacts with mercury(II) to form a red chelate of a 1:2 (mercury to ABTR) molar ratio. This chelate was enriched by solid phase extraction with C18 disks and the retained chelate eluted form the disks with dimethyl formamide (DMF). An enrichment factor of 50 was achieved. In the DMF medium, the molar absorptivity of the chelate is 1.21 X 105 L mol-1 cm-1 at 545 nm, and Beer's law is obeyed in the 0.01?3 ?g mL-1 range in the measured solution. The relative standard deviation for eleven sample replicate measurements at the 0.01 ?g mL-1 level is 1.7%. This method was applied to the determination of mercury in tobacco and tobacco additives and good preconcentration was found between proposed and comparative methods results. (author)

  12. Selective enrichment and determination of monoamine neurotransmitters by CU(II) immobilized magnetic solid phase extraction coupled with high-performance liquid chromatography-fluorescence detection.

    Science.gov (United States)

    He, Maofang; Wang, Chaozhan; Wei, Yinmao

    2016-01-15

    In this paper, iminodiacetic acid-Cu(II) functionalized Fe3O4@SiO2 magnetic nanoparticles were prepared and used as new adsorbents for magnetic solid phase extraction (MSPE) of six monoamine neurotransmitters (MNTs) from rabbit plasma. The selective enrichment of MNTs at pH 5.0 was motivated by the specific coordination interaction between amino groups of MNTs and the immobilized Cu(II). The employed weak acidic extraction condition avoided the oxidation of MNTs, and thus facilitated operation and ensured higher recoveries. Under optimal conditions, the recoveries of six MNTs from rabbit plasma were in the range of 83.9-109.4%, with RSD of 2.0-10.0%. When coupled the Cu(II) immobilized MSPE with high-performance liquid chromatography-fluorescence detection, the method exhibited relatively lower detection limits than the previously reported methods, and the method was successfully used to determine the endogenous MNTs in rabbit plasma. The proposed method has potential application for the determination of MNTs in biological samples. Also, the utilization of coordination interaction to improve the selectivity might open another way to selectively enrich small alkaloids from complex samples. PMID:26592630

  13. Preparation of 4-butylaniline-bonded silica gel for the solid-phase extraction of flavone glycosides.

    Science.gov (United States)

    Chu, Ganghui; Cai, Wensheng; Shao, Xueguang

    2015-04-01

    To extract flavone glycosides efficiently, a new extraction material based on 4-butylaniline-bonded silica gel was prepared using a two-step grafting method including a ring-opening reaction and synchronous hydrolysis. Preparation of the silica-based material was easily achieved under mild conditions, and the material was characterized by Fourier transform infrared spectroscopy, elemental analysis, and scanning electron microscopy. The material was used in solid-phase extraction, and the extraction can be performed in neutral conditions without regard to ionic strength. Selectivity tests of 14 compounds on the extraction cartridge showed that the material has a high affinity to flavone glycosides in contrast to octadecyl silica, and the extraction yields for four flavone glycosides were found to be >93%. Selectivity tests further reveal that the adsorption on its surface is likely attributed to multiple interactions, including hydrophobic interactions, ?-? interactions, and hydrogen bonding. To explore the applicability of 4-butylaniline-bonded silica gel, naringin and hesperidin from Simotang oral liquid were extracted, and the extraction yields were >90%, which is distinguished from <28% on octadecyl silica cartridge. PMID:25604828

  14. [Analysis of 43 pesticide residues in vegetables using solid-phase extraction and gas chromatography-triple quadrupole mass spectrometry].

    Science.gov (United States)

    Shi, Jiawei; Li, Jige; Wang, Yufei; Zhao, Yonggang

    2010-12-01

    A method for the simultaneous analysis of 43 pesticide residues in vegetables by gas chromatography coupled with triple quadrupole mass spectrometry (GC-QqQ-MS/MS) was developed and validated. The samples were extracted with acetonitrile, and then purified by solid-phase extraction (SPE). The detection of 43 pesticides was carried out by GC-QqQ-MS/MS in the multi-reaction monitoring (MRM) mode using external standard method. The overall recoveries determined at three spiked levels of 10, 80 and 100 microg/kg were 62.2%-170.0%, which in the recoveries of 36 pesticides were 70.0%-120.0%. The relative standard deviations (RSDs) were less than 18%. The limits of quantification (S/N > or =10) were 0.3-4.4 microg/kg. The method possesses low background and high sensitivity. It can be applied to the routine analysis of the 43 pesticides in vegetables. PMID:21438365

  15. Synthesis of a graphitic carbon nitride nanocomposite with magnetite as a sorbent for solid phase extraction of phenolic acids

    International Nuclear Information System (INIS)

    We have developed a facile in-situ growth method for the deposition of magnetite (Fe3O4) particles on the surface of a graphitic carbon nitride (g-C3N4) nanosheet. The material was characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The high affinity of g-C3N4 for phenolic acids in combination with the magnetism of Fe3O4 provides an efficient means for magnetic solid phase extraction. The adsorption, desorption and recoveries were examined. Under optimized conditions, the method has limits of detection in the range from 17.5–42.6 ng mL?1 (at an S/N of 3), and precisions from 2.8–3.8 % (for n?=?5). The method was successfully applied to the determination of protocatechuic, caffeic, and ferulic acids in Salicornia herbacea L. plant extracts. Recoveries ranged from 92.4–99.5 %. (author)

  16. Analysis of molluscicide metaldehyde in vegetables by dispersive solid-phase extraction and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Zhang, H Y; Wang, C; Xu, P J; Ma, Y Q

    2011-08-01

    This paper describes the development and validation of a new reverse-phase liquid chromatography-electrospray ionisation tandem mass spectrometric method (RP-HPLC-ESI-MS/MS) for the determination of metaldehyde in different kinds of vegetables. Metaldehyde was extracted with 20?ml acetonitrile from 10?g vegetable and followed by dispersive solid-phase extraction (Bondesil-primary secondary amine, PSA). The identification of metaldehyde was established by chromatographic retention times, analyte-specific fragmentation patterns and relative peak area ratios of two precursor/product ion pairs. The limit of detection of this method was 0.01?mg?kg(-1) using an injection volume of 5?µl. The repeatability of this method is excellent and the relative standard deviation (RSD) is less than 4%. PMID:21598139

  17. Biological evaluation of occupational exposure to nickel and lead with the solid-phase extraction method using Chromosorb-102 resin

    Directory of Open Access Journals (Sweden)

    Monireh Khadem

    2015-03-01

    Full Text Available     Background and Aim: The aim of this study was to assess exposure of workers in a metal industry to nickel and lead.   Materials and Methods: Extraction was done using the solid-phase extraction on Chromosorb-102 resin to prepare, concentrate and purify biological samples of urine, hair and nails of workers working in metal industries. The variables influencing response (pH, loading flow rate, elution solvent, and amount of resins, elution volume, and sample volume were examined and the procedure was optimized. The optimized procedure was, then, validated based on the “within-day” and “day-to-day” reproducibility experiments, using low, medium and high concentrations, leading to a satisfactory accuracy and precision. Finally, lead and nickel samples were taken from the workers and their concentrations determined voltammetrically.   Results: The optimum values for the examined parameters were as follows: pH = 9, ligand concentration = 0.05%, loading flow rate = 5 ml/min, elution solvent = 2M HNO3, amount of resins = 500 mg, elution volume = 15 ml, and sample volume up to 500 ml. A good reproducibility and repeatability was obtained for the optimized method under the existing conditions. Lead and nickel could be extracted with recoveries in the range of 94-100%. On the whole, the concentrations of nickel and lead in the workers’ biological samples were above the respective maximum permitted levels.   Conclusion: Solid-phase extraction procedure is a fast and simple method for preconcentrating and isolating analytes from biological samples. Considering the low concentrations of the analytes and presence of confounding factors in such samples, the procedure can be very effective for their preparation. The application of the developed method indicates that trace metal ions can be effectively purified and preconcentrated from different matrices like urine, hair and nail samples to assess occupational exposures.

  18. Preconcentration and analysis of Rhodamine B in water and red wine samples by using magnesium hydroxide/carbon nanotube composites as a solid-phase extractant.

    Science.gov (United States)

    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 ?g/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

  19. Evaluation of a novel solid phase extraction composite for the removal of actinides from acidic nuclear waste solutions

    Science.gov (United States)

    Tranter, T. J.; Mann, N. R.; Todd, T. A.; Šebesta, F.

    2003-01-01

    A novel approach for preparing granular solid phase extractants (SPE) for the separation of actinides has been developed, wherein the extractant is directly immobilised in an inert matrix. This allows substantially higher extractant loading in the SPE material than for conventional extraction chromatography resins. This approach utilises polyacrylonitrile (PAN) as the inert matrix material. The well-known actinide extractant octyl (phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) has been impregnated within PAN granules at extractant loadings from 20 to 33 wt. % CMPO. The porosity of the PAN matrix allows the active material to have rapid and complete access to the solution containing the target contaminants, resulting in improved kinetics and higher sorption capacities. The new CMPO-PAN SPE material was prepared in a batch process. Equilibrium batch contact tests were then performed with this material to determine the efficacy for removing plutonium and uranium from acid solutions as well as simulated solutions of tank waste currently stored at the Idaho National Engineering and Environmental Laboratory (INEEL). The potential interference of non-target metals was also investigated. The equilibrium behaviour of the new composite material will be discussed.

  20. Comparison of solid phase- and liquid/liquid-extraction for the purification of hair extract prior to multi-class pesticides analysis.

    Science.gov (United States)

    Duca, Radu-Corneliu; Salquebre, Guillaume; Hardy, Emilie; Appenzeller, Brice M R

    2014-04-01

    The present study focuses on the influence of a purification step - after extraction of pesticides from hair and before analysis of the extract - on the sensitivity of analytical methods including compounds from different chemical classes (both parent and metabolites). Sixty-seven pesticides and metabolites from different chemical classes were tested here: organochlorines, organophosphates, carbamates, pyrethroids, ureas, azoles, phenylpyrazoles and neonicotinoids. Two gas chromatography-negative chemical ionization-tandem mass spectrometry methods and one based on ultra-performance liquid chromatography-electrospray tandem mass spectrometry were used. Seven solid-phase extraction cartridges: C18, S-DVB, PS-DVB, GCB, GCB/PSA, SAX/PSA and Florisil/PSA were tested and compared to more classical liquid-liquid extraction procedures using ethyl acetate, hexane and dichloromethane. Although LLE allowed obtaining good results for some compounds, on the whole, SPE clearly provided better recovery for the majority of the pesticide residues tested in the present study. GCB/PSA was clearly the best suited to non-polar compounds such as organochlorines, pyrethroids and organophosphates, with recovery ranging from 45.9% (diflufenican) to 117.1% (parathion methyl). For hydrophilic metabolites (e.g. dialkyl phosphates and other organophosphate metabolites, pyrethroid metabolites, phenols and carbamate metabolites), the best results were obtained with PS-DVB, with recovery ranged from 10.3% (malathion monocarboxylic acid) to 93.1% (para-nitrophenol). For hydrophilic parent pesticides (e.g. neonicotinoids, carbamates, azoles) and metabolites without nucleophilic functions, the best recovery was obtained with SAX/PSA, with recovery ranging from 52.1% (3-hydroxycarbofuran) to 100.9% (3,4-dichloroaniline). Solid phase extraction was found to be more suitable than the liquid-liquid extraction for pesticides and their metabolites determination in terms of number of extracted compounds and their recovery. Moreover, the use of solid phase extraction cartridges has enabled the reduction of the analytical background noise, resulting in better chromatographic separations. PMID:24631817

  1. Fabrication of graphene/Fe3O4@polythiophene nanocomposite and its application in the magnetic solid-phase extraction of polycyclic aromatic hydrocarbons from environmental water samples.

    Science.gov (United States)

    Mehdinia, Ali; Khodaee, Nader; Jabbari, Ali

    2015-04-01

    Polythiophene (PT) was used as a surface modifier of graphene/Fe3O4 (G/Fe3O4) composite to increase merit of it, and also overcome some limitations and disadvantages of using G/Fe3O4 alone as solid phase extraction (SPE) sorbent. An in-situ chemical polymerization method was employed to prepare G/Fe3O4@PT nanocomposites. Application of this newly designed material in the magnetic SPE (MSPE) of polycyclic aromatic hydrocarbons (PAHs), as model analytes, in the environmental water samples was investigated. The characterization of the hybrid material was performed using transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray analysis, Fourier transform-infrared (FT-IR) spectroscopy and vibrating sample magnetometry. Seven important parameters, affecting the extraction efficiency of PAHs, including: amount of adsorbent, adsorption and desorption times, type and volume of the eluent solvent, initial sample volume and salt content of the sample were evaluated. The optimum extraction conditions were obtained as: 4 min for extraction time, 20 mg for sorbent amount, 100mL for initial sample volume, toluene as desorption solvent, 0.6 mL for desorption solvent volume, 6 min for desorption time and 30% (w/v) for NaCl concentration. Good performance data were obtained at the optimized conditions. Detection limits were in the range of 0.009-0.020 ?g L(-1) in the real matrix. The calibration curves were linear over the concentration ranges from 0.03 to 80 ?g L(-1) with correlation coefficients (R(2)) between 0.995 and 0.998 for all the analytes. Relative standard deviations were ranged from 4.3 to 6.3%. Appropriate recovery values, in the range of 83-107%, were also obtained for the real sample analysis. PMID:25813229

  2. A new graphene oxide/polypyrrole foam material with pipette-tip solid-phase extraction for determination of three auxins in papaya juice.

    Science.gov (United States)

    Wang, Lihui; Wang, Mingyu; Yan, Hongyuan; Yuan, Yanan; Tian, Jing

    2014-11-14

    A new material, graphene oxide/polypyrrole (GO/Ppy), was synthesized by mixing graphene oxide and polypyrrole in a specific proportion. It possesses a unique structure similar to that of foam. A homemade pipette-tip solid-phase extraction (PT-SPE) device, which is more simple and convenient than traditional devices, was used for saving reagents and operation time. When GO/Ppy was used as the adsorbent of PT-SPE for determining three auxins (indole-3-propionic acid, indole-3-butyric acid, and 1-naphthaleneacetic acid) present in trace amounts in papaya juice, it showed high affinity and adsorption capacity for all the three auxins. GO/Ppy-PT-SPE also had a significant capacity for eliminating the interferences from the papaya juice matrix. Under optimized conditions, a good linearity of auxins was obtained in the range 16.3-812.5 ng g(-1); the average recoveries at the three spiked levels of the three auxins ranged from 89.4% to 105.6% with the relative standard deviations ? 3.0%. Meanwhile, six papaya juice samples with different growth stages were analyzed under optimum conditions, and trace auxins in the range 18.3-100.6 ng g(-1) were observed. Because of its high selectivity, simplicity, and reliability, the GO/Ppy-PT-SPE method developed herein can be potentially applied for determining trace auxins in complex biological samples. PMID:25441342

  3. Optimization of a solid phase extraction and hydrophilic interaction liquid chromatography-tandem mass spectrometry method for the determination of metformin in dietary supplements and herbal medicines.

    Science.gov (United States)

    Wu, Ximei; Zhu, Binghui; Lu, Lin; Huang, Weixiong; Pang, Daiwen

    2012-07-15

    Metformin is one of the most common adulterants found in anti-diabetic dietary supplements and herbal medicines. An analytical method based on hydrophilic interaction chromatography (HILIC)/tandem mass spectrometry was developed and validated for the determination of metformin in dietary supplements and herbal medicines. Sample preparation involved solid phase extraction of the analyte using Plexa PCX cartridges, and cleanup by a primary-secondary amine (PSA) adsorbent for minimization of the matrix effect. Chromatographic separation was performed on a HILIC column using a mixture of 0.025 mol/L ammonium formate (pH 3) and acetonitrile (18:82, v/v) as the mobile phase at flow rate of 0.25 mL/min. The method was validated in four matrices (capsules, honeyed pills, tablets and oral solutions). The method had a good linear range (5-500 ng/mL), and the overall precision and accuracy ranged from 2.2% to 9.9% and 4.6% to 11.3%, respectively. PMID:25683423

  4. Determination of Triazine Herbicides in Drinking Water by Dispersive Micro Solid Phase Extraction with Ultrahigh-Performance Liquid Chromatography-High-Resolution Mass Spectrometric Detection.

    Science.gov (United States)

    Chen, Dawei; Zhang, Yiping; Miao, Hong; Zhao, Yunfeng; Wu, Yongning

    2015-11-11

    A novel dispersive micro solid phase extraction (DMSPE) method based on a polymer cation exchange material (PCX) was applied to the simultaneous determination of the 30 triazine herbicides in drinking water with ultrahigh-performance liquid chromatography-high-resolution mass spectrometric detection. Drinking water samples were acidified with formic acid, and then triazines were adsorbed by the PCX sorbent. Subsequently, the analytes were eluted with ammonium hydroxide/acetonitrile. The chromatographic separation was performed on an HSS T3 column using water (4 mM ammonium formate and 0.1% formic acid) and acetonitrile (0.1% formic acid) as the mobile phase. The method achieved LODs of 0.2-30.0 ng/L for the 30 triazines, with recoveries in the range of 70.5-112.1%, and the precision of the method was better than 12.7%. These results indicated that the proposed method had the advantages of convenience and high efficiency when applied to the analysis of the 30 triazines in drinking water. PMID:26487365

  5. NOVO SORVENTE DE HIDROFOBICIDADE REDUZIDA PARA EXTRAÇÃO EM FASE SÓLIDA: PREPARAÇÃO E CARACTERIZAÇÃO / NEW SORBENT WITH LOWER HYDROPHOBICITY FOR SOLID PHASE EXTRACTION: PREPARATION AND CHARACTERIZATION

    Scientific Electronic Library Online (English)

    Augusto S., Novais; Jarbas F., Ribeiro Filho; Eduardo M. F., Amaral; Anizio M., Faria.

    2015-02-01

    Full Text Available C18 chemically bonded sorbents have been the main materials used in solid phase extraction (SPE). However, due their high hydrophobicity some hydrophobic solutes are strongly retained leading to the consumption of larger quantities of organic solvent for efficient recoveries. This work presents a so [...] rbent with lower hydrophobicity but similar selectivity to the C18 sorbent, prepared by thermal immobilization of poly(dimethylsiloxane-co-alkylmethylsiloxane) (PDAS) on silica. PDAS has organic chains with methyl groups alternating with octadecyl or hexadecyl groups in its monomeric unities. For the Si(PDAS) sorbent presented, the polymeric layer was physically adsorbed on the silica surface with 12% carbon load. Although the coating of silica with the polymeric layer was incomplete, the PDAS provided better protection for the silica surface groups, promoting mostly hydrophobic interactions between analytes and the sorbent. Sorption isotherm studies revealed that the retention of hydrophobic solutes on Si(PDAS) was less intense than on conventional sorbents, confirming the lower hydrophobicity of the lab-made sorbent. Additional advantages of Si(PDAS) include simplicity and low cost of preparation, making this material a potential sorbent for the analysis of highly hydrophobic solutes.

  6. Determination of alachlor and its sulfonic acid metabolite in water by solid-phase extraction and enzyme-linked immunosorbent assay

    Science.gov (United States)

    Aga, D.S.; Thurman, E.M.; Pomes, M.L.

    1994-01-01

    Solid-phase extraction (SPE) and enzyme-linked immunosorbent assay (ELISA) were combined for the trace analysis of the herbicide alachlor and its major soil metabolite, ethanesulfonic acid (ESA). The anti-alachlor antibody cross-reacted with ESA, which produced false-positive detections of alachlor in water samples by immunoassay screens. Alachlor and ESA were isolated from water by SPE on a C18 resin and eluted sequentially with ethyl acetate and methanol. Alachlor is soluble in ethyl acetate while the anionic ESA is not. Thus ESA remained adsorbed on the C18 resin and was eluted later with methanol. The combination of SPE with ELISA effectivety separated and quantified both alachlor and ESA using the same antibody for two ELISA methods. The general method may have applicability for the separation of other herbicides and their ionic metabolites. The SPE-ELISA method has a, detection limit of 0.01 ??g/L for alachlor and 0.05 ??g/L for ESA, with a precision of ?? 10%. Analyses of surface and ground water samples were confirmed by gas chromatography/mass spectrometry and high-performance liquid chromatography with photodiode-array detection. Results showed widespread occurrence of ESA in surface and ground water of the midwestern United States, with concentrations ranging from 10 ??g/L.

  7. On-site quantitation of arsenic in drinking water by disk solid-phase extraction/mobile X-ray fluorescence spectrometry.

    Science.gov (United States)

    Hagiwara, Kenta; Koike, Yuya; Aizawa, Mamoru; Nakamura, Toshihiro

    2015-11-01

    A rapid and simple method was developed for As determination in drinking water by solid-phase extraction (SPE)/mobile X-ray fluorescence (XRF) spectrometry. A 50mL aqueous sample was adjusted to pH 3 with dilute hydrochloric acid, and then passed through a Ti and Zr-loaded carbon disk (TiZr-CD) to pre-concentrate the As. The SPE disk was adhered to an acrylic plate with cellophane tape, and then examined by mobile XRF spectrometry. The TiZr-CD adsorbed inorganic As (as As(III) and As(V)) and organic As (as methyl, phenyl and aromatic arsenic compounds) from water. The As calibration curve had good linearity over the range of 0.5-5?g, and the limit of detection was 0.10?g (2.0?gL(-1) in As concentration). The concentrations of As in well water samples were determined using the proposed method were similar to results obtained from atomic absorption spectrometry. The proposed method did not require a power supply or a toxic solution and/or gas in any analytical step, therefore it is suitable for the on-site determination of As in drinking water. PMID:26452891

  8. Solid-phase extraction of iridium from soil and water samples by using activated carbon cloth prior to its spectrophotometric determination.

    Science.gov (United States)

    Ozkantar, Nebiye; Yilmaz, Erkan; Soylak, Mustafa; Tuzen, Mustafa

    2015-08-01

    A solid-phase extraction method for separation and preconcentration of Ir(IV) ion by using activated carbon cloth (ACC) has been presented. Ir(IV) as their 1-(2-pyridylazo) 2-naphtol (PAN) chelate was adsorbed on ACC at pH 2.0 and was eluted from ACC with acidic dimethylformamide (DMF). The Ir(IV) concentration was determined at 536 nm as Ir(IV)-PAN complex by using UV-vis spectrophotometer. The analytical parameters including pH, sample and eluent flow rates, amount of PAN, eluent type, concentration, and sample volume were optimized. The effects of foreign ions on the recoveries of iridium were also investigated. The preconcentration factor was calculated as 60. The limit of detection (LOD) and the limit of quantification (LOQ) of the method were found as 0.039 and 0.129 ?g L(-1), respectively. The method was applied to soil and water samples for iridium determination. PMID:26160741

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

    Science.gov (United States)

    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 ?g kg(-1), respectively. PMID:22980859

  10. Determination of rotenone residues in raw honey by solid-phase extraction and high-performance liquid chromatography.

    Science.gov (United States)

    Jiménez, J J; Bernal, J L; del Nozal, M J; Novo, M; Higes, M; Llorente, J

    2000-02-25

    A method for determining residues of the insecticide rotenone in raw-honey by high-performance liquid chromatography (HPLC) is described. To extract the residues, organic solvents such as ethyl acetate, n-hexane/dichloromethane and solid-phase extraction with octadecylsilane cartridges or Florisil packed columns were tested. Determination was carried out by reversed-phase HPLC using acetonitrile-buffer phosphate (pH 7) (60:40, v/v) as mobile phase and detection at 210 nm. Although the data showed that the two extraction methods were able to isolate the pesticide residues, the extraction on octadecylsilane cartridges was preferred due to its simplicity and higher recovery. Recoveries depended strongly on the fortification level for the two extraction procedures. Practical determination limits of 0.015 mg/kg were obtained. In the analysis of honeys, from beehives treated with rotenone at therapeutical doses for 1 month, residual amounts below 0.2 mg/kg were found. PMID:10735287

  11. Determination of enrofloxacin by room-temperature phosphorimetry after solid phase extraction on an acrylic polymer sorbent

    Science.gov (United States)

    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.

  12. Colorimetric Solid Phase Extraction for the Measurement of Total I (Iodine, Iodide, and Triiodide) in Spacecraft Drinking Water

    Science.gov (United States)

    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.

  13. Determination of fipronil in bovine plasma by solid-phase extraction and liquid chromatography with ultraviolet detection

    Scientific Electronic Library Online (English)

    Yara P., Cid; Thais P., Ferreira; Deborah M. V. C., Medeiros; Rodrigo M., Oliveira; Nathália C. C., Silva; Viviane S., Magalhães; Fábio B., Scott.

    Full Text Available A fast and efficient method has been developed and validated for the determination of fipronil in bovine plasma. Samples were subjected to solid-phase extraction (SPE) followed by reversed phase liquid chromatography (LC) separation, using acetonitrile/water (60:40 v/v) as the mobile phase with a fl [...] ow rate of 1.0 mL/min and ultraviolet (UV) detection at 210 nm. Ethiprole was used as the internal standard (IS). The method was found to be linear over the range 5-500 ng/mL (r = 0.999). The limit of quantitation (LOQ) was validated at 5 ng/mL. The method was successfully applied to monitor plasma concentrations following subcutaneous administration of fipronil in cattle.

  14. Development of an extractive spectrophotometric method for uranium using MWCNTs as solid phase and arsenazo(III) as chromophore

    International Nuclear Information System (INIS)

    Multiwalled carbon nanotubes (MWCNTs) based sorptive extraction method for uranium (U) from aqueous solutions has been developed. The proposed method was optimized by evaluating the analytical parameters including pH, eluent type, flow rates of sample and eluent, etc. The adsorption capacity of MWCNTs was found to be 9.80 ?g g-1, while the detection limit based on 3? criterion was 1.9 ?g L-1. The presented method was applied for the estimation of U in ore sample. Effect of potentially interfering ions was also studied and were found to inert not interfering with U during the analysis. The results suggest that MWCNTs can be used as reliable solid phase for preconcentration and arsenazo-III as chromophore for U spectrometric determination from aqueous solutions. (author)

  15. Robot-performed synthesis of [11C]CH3-methionine with isolation by means of solid-phase extraction

    International Nuclear Information System (INIS)

    Robot-performed technology of synthesizing radiopharmaceutical preparation 11CH3-methionine, used in positron-emission tomography of brain to evaluate the rate of protein biosynthesis was developed. The technology is based on the synthesis of 11CH3-methionine from[11C]-CHI and DL-homocysteinethiolactone with subsequent isolation of the preparation by the method of solid-phase extraction. Activity of the preparation synthesized is 0.13-0.17 Ci, specific activity -325-850 Ci/mmol, total duration of the synthesis from the moment of irradiation end is 16-19 min, radiochemical yield, as regards 11CH3I corrected for carbon-11 decay, is 60 %

  16. Simultaneous determination of seven synthetic colorants in wine by dispersive micro-solid-phase extraction coupled with reversed-phase high-performance liquid chromatography.

    Science.gov (United States)

    Zhang, Yun; Zhou, Hua; Wang, Yougang; Wu, Xianglun; Zhao, Yonggang

    2015-02-01

    A novel and effective dispersive micro-solid-phase extraction (d-µ-SPE) using ethanediamine-functionalized magnetic Fe3O4 polymer (EDA-MP) as an efficient adsorbent in wine sample was developed. Based on this, a simple and time-saving analytical method for the simultaneous determination of seven synthetic colorants (i.e., tartrazine, amaranth, carmine, sunset yellow, allura red, brilliant blue and erythrosine) in wine by reversed-phase high-performance liquid chromatography with an ultraviolet detector was established. The experimental parameters, including the chromatographic retention behavior of studied synthetic colorants, the effect of the usage amount of cross-linking monomer, the effect of the usage amount of EDA-MP on the recovery and the recyclability of the adsorbents, were studied in detail. The results showed that the EDA-MP could be reused efficiently at least six times. Under optimized conditions, the recoveries for all analytes were in the range of 88.6-105.2%, with the intraday relative standard deviations (RSDs) ranging from 2.1 to 8.2% and the interday RSDs ranging from 3.4 to 8.7%, and all the analytes had good linearities in the tested ranges with correlation coefficients (r(2)) >0.9995. The limits of quantification for seven synthetic colorants were between 0.12 and 0.45 mg L(-1). The developed method was successfully applied to wine samples, and it was confirmed that the EDA-MP particles were highly effective d-µ-SPE materials. PMID:24850700

  17. Development of a novel, fast, sensitive method for chromium speciation in wastewater based on an organic polymer as solid phase extraction material combined with HPLC-ICP-MS.

    Science.gov (United States)

    Jia, Xiaoyu; Gong, Dirong; Xu, Bin; Chi, Qiaoqiao; Zhang, Xian

    2016-01-15

    Speciation analysis of inorganic chromium in wastewater is of great significance for the monitoring of environmental pollution. In this work, N,N-bis(2-aminoethyl)ethane-1,2-diamine functionalized poly(chloromethyl styrene-co-styrene) was synthesized, characterized and used as the adsorbent to preconcentrate chromium species in environmental waters by on line solid-phase extraction (SPE). The trace speciation analysis of Cr(III) and Cr(VI) in wastewater has been used by short-column high-performance liquid chromatography hyphenated to inductively coupled plasma spectrometry (HPLC-ICP-MS) after on-line SPE. Cr(III) and Cr(VI) have been adsorbed on the anion exchange column after transforming the cationic Cr(III) to an anionic [Cr(III)-EDTA](-) complex devoid of re-dox reagent, and then eluted rapidly (within seconds) with a very low concentration of tetrabutylammonium hydroxide (TBAH) solution. This method provides a reliable on-line preconcentration method and detection coupled technique. Under the optimized conditions, high enrichment factors have been obtained for Cr(VI) and [Cr(III)-EDTA](-) with 30mL sample solution up to 105 and 128, respectively. The low detection limits of 0.0068ngmL(-1) and 0.0041ngmL(-1), with the relative standard deviations (RSDs) of 4.3% and 3.6% were obtained for Cr(VI) and [Cr(III)-EDTA](-), respectively. The developed method was validated by analyzing Certified Reference Materials GSBZ50027-94, and the spike tests were also performed. At the same time, thanks to the merit of simple operation, rapid adsorption/desorption dynamics, high enrichment and low LODs, the established method was applied to analyze three wastewater samples from different discharge port. PMID:26592590

  18. A hydrazone covalent organic polymer based micro-solid phase extraction for online analysis of trace Sudan dyes in food samples.

    Science.gov (United States)

    Zhang, Chengjiang; Li, Gongke; Zhang, Zhuomin

    2015-11-01

    Covalent organic polymers (COPs) connected by covalent bonds are a new class of porous network materials with large surface area and potential superiority in sample pretreatment. In this study, a new hydrazone linked covalent organic polymer (HL-COP) adsorbent was well-designed and synthesized based on a simple Schiff-base reaction. The condensation of 1,4-phthalaldehyde and 1,3,5-benzenetricarbohydrazide as organic building blocks led to the synthesis of HL-COP with uniform particle size and good adsorption performance. This HL-COP adsorbent with high hydrophobic property and rich stacking ? electrons contained abundant phenyl rings and imine (CN) groups throughout the entire molecular framework. The adsorption mechanism was explored and discussed based on ?-? affinity, hydrophobic effect, hydrogen bonding and electron-donor-acceptor (EDA) interaction, which contributed to its strong recognition affinity to target compounds. Enrichment factors were 305-757 for six Sudan dyes by HL-COP micro-solid phase extraction (?-SPE), indicating its remarkable preconcentration ability. Furthermore, the adsorption amounts by HL-COP ?-SPE were 1.0-11.0 folds as those by three commonly used commercial adsorbents. Then, HL-COP was applied as adsorbent of online ?-SPE coupled with high performance liquid chromatography (HPLC) for enrichment and analysis of trace Sudan dyes in food samples with detection limit of 0.03-0.15?g/L. The method was successfully applied for online analysis of chilli powder and sausage samples. Sudan II and Sudan III in one positive chilli powder sample were actually found and determined with concentrations of 8.3 and 6.8?g/kg, respectively. The recoveries of chilli powder and sausage samples were in range of 75.8-108.2% and 73.8-112.6% with relative standard deviations of 1.2-8.5% and 1.9-9.4% (n=5), respectively. The proposed method was accurate, reliable and convenient for the online simultaneous analysis of trace Sudan dyes in food samples. PMID:26456513

  19. Determining plasma morphine levels using GC-MS after solid phase extraction to monitor drug levels in the postoperative period

    Scientific Electronic Library Online (English)

    Veronica, Santos; Karin Jannet Vera, López; Luciana Moraes, Santos; Mauricio, Yonamine; Maria José Carvalho, Carmona; Silvia Regina Cavani Jorge, Santos.

    Full Text Available OBJECTIVE: To implement a selective and sensitive analytical method to quantify morphine in small volumes of plasma by gas-liquid chromatography-mass spectrometry (GC-MS), aimed at post-operatively monitoring the drug. METHOD: A gas-liquid chromatographic method with mass detection has been develope [...] d to determine morphine concentration in plasma after solid phase extraction. Morphine-d3 was used as an internal standard. Only 0.5 mL of plasma is required for the drug solid-phase extraction in the Bond Elut-Certify®, followed by the quantification of morphine derivative by GC-MS using a linear temperature program, a capillary fused silica column, and helium as the carrier and make-up gas. The method was applied to determine morphine content in plasma samples of four patients during the postoperative period of cardiac surgery. Patient-controlled analgesia with morphine was performed by a venous catheter, and a series of venous blood samples were collected. After the oro-After the orotracheal extubation, morphine plasma levels were monitored for up to 36 hours. RESULTS: The run time was 16 minutes because morphine and the internal standard were eluted after 8.8 minutes. The GC-MS method had 0.5 -1000 ng/mL linearity range (r²=0.9995), 0.1 ng/mL limit of detection, intraday and interday precision equivalent to 1.9% and 6.8%, and 0.1% and 0.8% systematic error (intraday and interday, respectively). The analytical method showed optimal absolute (98%) and relative (100.7%) recoveries. Morphine dose requirements and plasma levels are discussed. CONCLUSION: The analytical gas-liquid chromatography-mass spectrometry method is selective and adequate for morphine measurements in plasma for applications in clinical studies.

  20. Fully automated synthesis of 11C-acetate as tumor PET tracer by simple modified solid-phase extraction purification

    International Nuclear Information System (INIS)

    Introduction: Automated synthesis of 11C-acetate (11C-AC) as the most commonly used radioactive fatty acid tracer is performed by a simple, rapid, and modified solid-phase extraction (SPE) purification. Methods: Automated synthesis of 11C-AC was implemented by carboxylation reaction of MeMgBr on a polyethylene Teflon loop ring with 11C-CO2, followed by acidic hydrolysis with acid and SCX cartridge, and purification on SCX, AG11A8 and C18 SPE cartridges using a commercially available 11C-tracer synthesizer. Quality control test and animals positron emission tomography (PET) imaging were also carried out. Results: A high and reproducible decay-uncorrected radiochemical yield of (41.0±4.6)% (n=10) was obtained from 11C-CO2 within the whole synthesis time about 8 min. The radiochemical purity of 11C-AC was over 95% by high-performance liquid chromatography (HPLC) analysis. Quality control test and PET imaging showed that 11C-AC injection produced by the simple SPE procedure was safe and efficient, and was in agreement with the current Chinese radiopharmaceutical quality control guidelines. Conclusion: The novel, simple, and rapid method is readily adapted to the fully automated synthesis of 11C-AC on several existing commercial synthesis module. The method can be used routinely to produce 11C-AC for preclinical and clinical studies with PET imaging. - Highlights: • A fully automated synthesis of 11C-acetate by simple modified solid-phase extraction purification has been developed. • Typical non-decay-corrected yields were (41.0±4.6)% (n=10) • Radiochemical purity was determined by radio-HPLC analysis on a C18 column using the gradient program, instead of expensive organic acid column or anion column. • QC testing (RCP>99%)

  1. Volatile phytochemical composition of rhizome of ginger after extraction by headspace solid-phase microextraction, petroleum ether extraction and steam distillation extraction

    Directory of Open Access Journals (Sweden)

    Zhannan Yang, Weiping Yang, Quancai Peng, Qiansong He, Yong Feng, Shiqiong Luo, Zhengwen Yu

    2009-12-01

    Full Text Available The sampling techniques headspace solid-phase microextraction (HS-SPME, petrol ether extraction (PEE and steam distillation extraction (SDE were compared for the GC-MS of volatile constituents present in ginger (Zingiber officinale. The effects of different parameters, such as extraction fibers, extraction time, extraction temperature and particle size ranges, on the HS-SPME of rhizome of ginger were investigated. Zingiberene (53.12% were predominant components of ginger samples obtained by HS-SPME whereas those levels were 39.01% in the same samples by PEE and 35.05% in those by SDE, respectively. HS-SPME with polydimethylsiloxane (PDMS fiber was more selective and particularly efficient for the isolation of volatile phytochemical composition and afforded a higher yield of total compounds than PEE and SDE. The specific compound isolated by SPME, which due to effective fiber, was much larger than that isolated by PEE or SDE. HS-SPME is a powerful tool for determining the volatile constitutes present in the traditional Chinese medicines.

  2. Magnetic graphene oxide modified with choline chloride-based deep eutectic solvent for the solid-phase extraction of protein.

    Science.gov (United States)

    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

  3. Integrated Solid-Phase Extraction-Capillary Liquid Chromatography (speLC) Interfaced to ESI-MS/MS for Fast Characterization and Quantification of Protein and Proteomes

    DEFF Research Database (Denmark)

    Falkenby, Lasse Gaarde; Such-Sanmartín, Gerard; Larsen, Martin Røssel; Vorm, Ole; Bache, Nicolai; Jensen, Ole Nørregaard

    2014-01-01

    The high peptide sequencing speed provided by modern hybrid tandem mass spectrometers enables the utilization of fast liquid chromatographic (LC) separation techniques. We present a robust solid-phase extraction/capillary LC system (speLC) for 5-10 min separation of semicomplex peptide mixtures prior to ESI-MS/MS for peptide sequencing. This speLC-MS/MS system eliminates sample-to-sample carry-over by using disposable micropipette solid-phase extraction tips (StageTips) for peptide sample loadin...

  4. An On-Line Solid Phase Extraction-Liquid Chromatography-Tandem Mass Spectrometry Method for the Determination of Perfluoroalkyl Acids in Drinking and Surface Waters

    OpenAIRE

    Mazzoni, Michela; Rusconi, Marianna; Valsecchi, Sara; Martins, Claudia P. B.; Polesello, Stefano

    2015-01-01

    An UHPLC-MS/MS multiresidue method based on an on-line solid phase extraction (SPE) procedure was developed for the simultaneous determination of 9 perfluorinated carboxylates (from 4 to 12 carbon atoms) and 3 perfluorinated sulphonates (from 4 to 8 carbon atoms). This work proposes using an on-line solid phase extraction before chromatographic separation and analysis to replace traditional methods of off-line SPE before direct injection to LC-MS/MS. Manual sample preparation was reduced to s...

  5. Therapeutic drug monitoring of risperidone and 9-hydroxyrisperidone in serum with solid-phase extraction and high-performance liquid chromatography.

    Science.gov (United States)

    Price, M C; Hoffman, D W

    1997-06-01

    This laboratory developed a simple and efficient solid-phase extraction method that is combined with high-performance liquid chromatography for rapid and precise therapeutic monitoring of risperidone (Risperdal) in blood concentrations. The solid-phase extraction uses a mixed bed column. Sensitivity of the chromatographic method is 0.5 ng/ml (180 pmol/ml) of drug in serum, and separations can be performed in a 15-minute chromatographic run. Advantages of this approach include enhanced speed, sensitivity, and efficiency. A high level of sensitivity may be achieved because of the absence of interference from other drugs, metabolites, or serum components. PMID:9200776

  6. Application of mesoporous carbon as a solid-phase microextraction fiber coating for the extraction of volatile aromatic compounds.

    Science.gov (United States)

    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 ?g/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 ?g/L ranged from 73.1 to 99.1%. PMID:26041569

  7. Iron oxide functionalized graphene nano-composite for dispersive solid phase extraction of chemical warfare agents from aqueous samples.

    Science.gov (United States)

    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

  8. Solid phase extraction-preconcentration and high performance liquid chromatographic determination of 2-mercapto-(benzothiazole, benzoxazole and benzimidazole) using copper oxide nanoparticles.

    Science.gov (United States)

    Parham, Hooshang; Khoshnam, Farzaneh

    2013-09-30

    This study introduces a novel method of solid phase extraction (SPE), preconcentration and HPLC determination of 2-mercaptobenzimidazole (2MBI), 2-mercaptobenzoxazole (2MBO) and 2-mercaptobenzothiazole (2MBT) from an aqueous solution by a SPE cartridge loaded with copper oxide nanoparticles. Results demonstrated that copper oxide nanoparticles are quite efficient for extraction and preconcentration of trace amounts of these mercaptans at room temperature. The study also investigated the effects of parameters such as pH, buffer and its volume, electrolyte concentration, flow rate of the test solution, composition and volume of the desorbing solvent, accepted tolerable volume, amount of adsorbent, reusability of cartridges and evidence of some co-existing species on extraction and determination of the above mentioned mercaptans. The method showed good linearity for determination of these mercaptans in the range of 0.01-10 ?g mL(-1) with regression coefficients better than 0.9969. The limits of detection (LODs) evaluations were 0.0021, 0.0027 and 0.0019 ?g mL(-1) for 2MBT, 2MBO and 2MBI, respectively. The relative standard deviations (RSDs) for 0.2 ?g mL(-1) and 5 ?g mL(-1) of the measured mercaptans were below 3.04% and 4.23%, respectively. Ramin Power Plant (3000 MW, Ahvaz, Iran) cooling water containing some 2MBT (as corrosion inhibitor) was used as the real sample. Recovery tests with spiked levels of 2MBT, 2MBI and 2MBO were carried out and satisfied results were obtained. PMID:23953446

  9. Magnetic nanoparticles with hydrophobicity and hydrophilicity for solid-phase extraction of polycyclic aromatic hydrocarbons from environmental water samples.

    Science.gov (United States)

    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

  10. Preparation and evaluation of molecularly imprinted solid-phase micro-extraction fibers for selective extraction of phthalates in an aqueous sample

    Energy Technology Data Exchange (ETDEWEB)

    He Juan, E-mail: juanhe@haut.edu.cn [School of Chemistry and Chemical Engineering, Henan University of, Technology, LianHua Road, Zhengzhou 450051 (China); Lv Ruihe; Zhan Haijun; Wang Huizhi; Cheng Jie; Lu Kui; Wang Fengcheng [School of Chemistry and Chemical Engineering, Henan University of, Technology, LianHua Road, Zhengzhou 450051 (China)

    2010-07-26

    A novel molecularly imprinted polymer (MIP) that was applied to a solid-phase micro-extraction (SPME) device, which could be coupled directly to gas chromatograph and mass spectrometer (GC/MS), was prepared using dibutyl phthalate (DBP) as the template molecule. The characteristics and application of this fiber were investigated. Electron microscope images indicated that the MIP-coated solid-phase micro-extraction (MI-SPME) fibers were homogeneous and porous. The extraction yield of DBP with the MI-SPME fibers was higher than that of the non-imprinted polymer (NIP)-coated SPME (NI-SPME) fibers. The MI-SPME fibers had a higher selectivity to other phthalates that had similar structures as DBP. A method was developed for the determination of phthalates using MI-SPME fibers coupled with GC/MS. The extraction conditions were optimized. Detection limits for the phthalate samples were within the range of 2.17-20.84 ng L{sup -1}. The method was applied to five kinds of phthalates dissolved in spiked aqueous samples and resulted in recoveries of up to 94.54-105.34%, respectively. Thus, the MI-SPME fibers are suitable for the extraction of trace phthalates in complicated samples.

  11. Chitosan-poly(m-phenylenediamine)@Fe?O? nanocomposite for magnetic solid-phase extraction of polychlorinated biphenyls from water samples.

    Science.gov (United States)

    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

  12. Pesticide residue analysis in cereal-based baby foods using multi-walled carbon nanotubes dispersive solid-phase extraction.

    Science.gov (United States)

    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 ?g/kg, which were lower than the European Union maximum residue limits for pesticide residues in cereal-based baby foods. PMID:22623047

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  15. SOLID PHASE EXTRACTION OF Cd(II) AND Pb(II) IONS BY A NEW CARBOTHIOAMIDE DERIVATIVE

    Scientific Electronic Library Online (English)

    DUYGU, OZDES; CELAL, DURAN; HACER, BAYRAK; HUSEYIN, SERENCAM; HASAN, BASRI SENTURK.

    2013-12-01

    Full Text Available An effective, simple, low cost and accurate sorption-spectrophotometric platform for the extractions and subsequent quantifications of Cd(II) and Pb(II) ions in food and environmental samples has been described in this dissertation. The separation and preconcentration of the analyte ions were accomp [...] lished by solid phase extraction method based on the adsorption of their N-(4-methylphenyl)-2-{[(4-phenyl-5-pyridin-4-yl-H-1,2,4-triazol-3-yl)thio]acetyl} hydrazinecarbothioamide (MFPTAHK) complex on Amberlite XAD-8 resin in a mini column. The developed method was systematically investigated in different set of experimental parameters that influence the separation and preconcentration of Cd(II) and Pb(II) ions. The precision of the method was determined by reproducibility studies and expressed as relative standard deviations (RSD %) which were less than 4% for both analyte ions. The limits of detections (LODs) for Cd(II) and Pb(II) ions based on the three times the standard deviation of the blanks (N:10) were found to be 0.31 ?g L-1 and 0.86 ?g L-1, respectively. The developed SPE procedure was utilized for the simultaneous extraction and determinations of Cd(II) and Pb(II) ions levels in rice, cracked wheat and red lentil as food samples and various water samples.

  16. Solid-phase extraction of urinary 11-dehydrothromboxane B2 for reliable determination with radioimmunoassay.

    Science.gov (United States)

    Riutta, A; Mucha, I; Vapaatalo, H

    1992-05-01

    In this paper we elaborate a one-step procedure for the selective extraction of urinary 11-dehydrothromboxane B2 on octylsilyl silica cartridges for reliable determination with radioimmunoassay. The immunoreactivity profile of nonselectively extracted urine after HPLC separation showed that as much as 70% of the total 11-dehydrothromboxane B2 immunoreactivity comigrates with polar interfering material. Its amount could be considerably decreased using acetonitrile:water (18:82, v/v) as wash solvent before elution of 11-dehydrothromboxane B2 from the cartridge. Alternatively, very high immunoreactive purity was achieved without the preceding wash step by selective elution of the analyte with dichloromethane:hexane (70:30). After both optimized steps in the extraction procedure were combined, immunoreactivity was found only in HPLC fractions corresponding to the retention volume of authentic 11-dehydrothromboxane B2. The homogeneity of this immunoreactivity was confirmed by two-step HPLC separation. A significant correlation of values was observed between samples measured after extraction and those measured after subsequent HPLC purification. A high correlation was also found with concentrations determined by radioimmunoassay using four different antisera. The values of 24 h excretion of 11-dehydrothromboxane B2 in 10 male volunteers (595 +/- 114 ng/g creatinine, mean +/- SD) as well as the inhibitory effect of acetylsalicylic acid (80 +/- 13%) closely correspond with those reported in the literature. This selective extraction procedure provides a high validity in radioimmunoassay without requiring any further purification step. PMID:1519756

  17. Solid-phase extraction-spectrophotometric determination of uranium(VI) in natural waters.

    Science.gov (United States)

    Sadeghi, Susan; Mohammadzadeh, Darush; Yamini, Yadollah

    2003-03-01

    A method for the extraction and determination of uranyl ion in natural waters using octadecyl bonded silica membrane disks modified with piroxicam and spectrophotometry with arsenazo(III) is proposed. The perconcentration step was studied with regard to experimental parameters such as amount of extractant, type and amount of eluent, pH, flow rates and tolerance limit of diverse ions on the recovery of uranyl ion. The limit of detection of the proposed method is 0.4 micro g L(-1) of uranyl. The method was applied to the recovery of uranyl from different water samples. PMID:12638056

  18. Solid-phase extraction-spectrophotometric determination of uranium(VI) in natural waters

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi, Susan; Mohammadzadeh, Darush [Department of Chemistry, University of Birjand, Birjand (Iran); Yamini, Yadollah [Department of Chemistry, Tarbiat Moddars University, Tehran (Iran)

    2003-03-01

    A method for the extraction and determination of uranyl ion in natural waters using octadecyl bonded silica membrane disks modified with piroxicam and spectrophotometry with arsenazo(III) is proposed. The perconcentration step was studied with regard to experimental parameters such as amount of extractant, type and amount of eluent, pH, flow rates and tolerance limit of diverse ions on the recovery of uranyl ion. The limit of detection of the proposed method is 0.4 {mu}g L{sup -1} of uranyl. The method was applied to the recovery of uranyl from different water samples. (orig.)

  19. In Situ Synthesis of Porous Carbons by Using Room-Temperature, Atmospheric-Pressure Dielectric Barrier Discharge Plasma as High-Performance Adsorbents for Solid-Phase Microextraction.

    Science.gov (United States)

    Lin, Yao; Wu, Li; Xu, Kailai; Tian, Yunfei; Hou, Xiandeng; Zheng, Chengbin

    2015-09-21

    A one-step, template-free method is described to synthesize porous carbons (PCs) in situ on a metal surface by using a room-temperature, atmospheric-pressure dielectric barrier discharge (DBD) plasma. This method not only features high efficiency, environmentally friendliness, and low cost and simple equipment, but also can conveniently realize large-area synthesis of PCs by only changing the design of the DBD reactor. The synthesized PCs have a regulated nestlike morphology, and thus, provide a high specific surface area and high pore volume, which result in excellent adsorption properties. Its applicability was demonstrated by using a PC-coated stainless-steel fiber as a solid-phase microextraction (SPME) fiber to preconcentrate polycyclic aromatic hydrocarbons (PAHs) prior to analysis by gas chromatography with flame ionization detection (GC-FID). The results showed that the fiber exhibited excellent enrichment factors (4.1×10(4) to 3.1×10(5)) toward all tested PAHs. Thus, the PC-based SPME-GC-FID provides low limits of detection (2 to 20?ng?L(-1)), good precision (<7.8%), and good recoveries (80-115%) for ultra-sensitive determination of PAHs in real water samples. In addition, the PC-coated fiber could be stable enough for more than 500 replicate extraction cycles. PMID:26267394

  20. Solid phase extraction and determination of sub-ppb levels of hazardous Hg2+ ions.

    Science.gov (United States)

    Shamsipur, Mojtaba; Shokrollahi, Ardeshir; Sharghi, Hashem; Eskandari, Mohammad Mehdi

    2005-01-31

    A simple, rapid and reliable method has been developed to selectively separate and concentrate ultra trace amounts of mercury(II) ions from aqueous samples for its highly sensitive measurement by cold vapor atomic absorption spectrometry (CV-AAS). The Hg(2+) ions were adsorbed selectively and quantitatively during the passage of aqueous samples through octadecyl silica membrane disks modified by isopropyl 2-[(isopropoxycarbothiolyl)disulfanyl]ethane thioate (IIDE). The retained Hg(2+) ions were then stripped from the disk with minimal amounts of 0.5 M hydrobromic acid (two 8 ml portions) as eluent, and determined by CV-AAS. The break-through volume of the method is greater than 3000 ml, which results in enrichment factors >150. Maximum capacity of the membrane disks modified with 10mg of the ligand was found to be 350+/-30 microg of mercury(II), and the limit of detection is 0.005 ng ml(-1). The effect of various cationic interferences on the recovery of mercury in binary mixtures was studied. The method was applied to the recovery of Hg(2+) ions from different synthetic and tap water samples, as well as the determination of mercury in human hair samples. PMID:15629571

  1. Titanium dioxide nanoparticle based solid phase extraction of trace Alizarin Violet, followed by its spectrophotometric determination

    International Nuclear Information System (INIS)

    Nanometer-sized titanium dioxide (nano-TiO2) is shown to be a viable material for the preconcentration of Alizarin Violet (AV, a common dye and biological stain). In the preconcentration step, a 5-ring cyclic ester is formed between the ortho-dihydroxy groups of AV and two hydroxy groups of the titanic acid on the surface of the nano-TiO2. Under optimized conditions, the adsorption capacity of nano-TiO2 is???20 ?g?·?mg?1, the adsorption efficiency is 98 %. The adsorbed AV can be eluted with 5 mL of 5 mol?·?L?1 5-sulfosalicylic acid with an elution efficiency of more than 91.8 %. The preconcentration factor is 50 in case of 250 mL samples. Spectrophotometric determination of AV in the eluate gives a linear calibration plot in the range between 18.8 ?g?·?L?1 and 10 mg?·?L?1 and a detection limit (3 s; for n?=?11) of 18.8 ?g?·?L?1. The method is simple and fast. It was successfully applied to the analysis of AV in spiked natural waters, and recoveries were found to range between 94.2 and 97.3 %. (author)

  2. Determination of the Antibiotic Oxytetracycline in Commercial Milk by Solid-Phase Extraction: A High-Performance Liquid Chromatography (HPLC) Experiment for Quantitative Instrumental Analysis

    Science.gov (United States)

    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).…

  3. Forensic analysis of high explosives residues in post-blast water samples employing solid phase extraction for analyte pro-concentration

    International Nuclear Information System (INIS)

    Nitro aromatic, nitramine and nitrate ester compounds are a major group of high order explosive or better known as military explosives. Octahydro-1,3,5,7-tetrazocine (HMX), 1,3,5-hexahydro-1,3,5-trinitro triazine (RDX), 2,4,6-trinitro-toluene (TNT), pentaerythritol tetranitrate (PETN) and 2,4-dinitrotoluene (2,4-DNT) are secondary high explosives classified as most commonly used explosives components. There is an increasing demand for pre-concentration of these compounds in water samples as the sensitivity achieved by instrumental analytical methods for these high explosives residues are the main drawback in the application at trace levels for forensic analysis. Hence, a simple cartridge solid phase extraction (SPE) procedure was optimized as the off-line extraction and pre-concentration method to enhance the detection limit of high explosive residues using micellar electrokinetic chromatography (MEKC) and gas chromatography with electron-capture detection (GC-ECD) methods. The SPE cartridges utilized LiChrolut EN as the SPE adsorbent. By emplying pre-concentration using SPE, the detection limits of the target analytes in water sample were lowered by more than 1000 times with good percentage recovery (>87%) for MEKC method and lowered by 120 times with more than 2 % percentage recovery for GC-ECD methods. In order to test the feasibility of the developed method to real cases, post-blast water samples were analyzed. The post-blast water samples which were collected from Baling Bom training range, Ulu Kinta, Perak contained RDX and PETN in the range of 0.05 - 0.17 ppm and 0.0124 - 0.0390 ppm respectively. (author)

  4. A sensitive method for determining total vanadium in water samples using colorimetric-solid-phase extraction-fiber optic reflectance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Filik, Hayati, E-mail: filik@istanbul.edu.tr [Istanbul University, Faculty of Engineering, Department of Chemistry, 34320 Istanbul (Turkey); Yanaz, Zeynep [Istanbul University, Faculty of Engineering, Department of Chemistry, 34320 Istanbul (Turkey)

    2009-12-30

    A selective colorimetric-solid-phase extraction (C-SPE) method for the determination of total vanadium in water samples was developed. This method introduced a new variation of C-SPE. The colour reaction is based on the reaction of vanadium(V) ternary complex formed with 1-(2-Pyridylazo)-2-naphtol (PAN) in the presence hydrogen peroxide (H{sub 2}O{sub 2}). In this technique, the target analytes in samples are extracted onto solid matrix loaded with a colorimetric reagent and then quantified directly on the adsorbent surface by using a miniature fiber optic reflectance spectrometer. The measurements were carried out at a wavelength of 589.4 nm since it yielded the largest divergence different in reflectance spectra before and after reaction with the vanadium. The overall time required for the C-SPE procedure was {approx}20 min. The amount of concentrated V is then determined in a few seconds by using miniature reflectance spectrometer. At the optimal conditions, a calibration curve was constructed, revealing a linear range of 0.05-0.52 mg L{sup -1} and a detection limit as low as 0.01 mg L{sup -1} while the RSD lower than 2.8%. In order to verify the accuracy of the method, a certified reference water samples (TMDA) were analysed and the results obtained were in good agreement with the certified values. The proposed method was applied to the determination of vanadium in tap water, seawater samples with a recovery for the spiked samples in the range of 98-102%.

  5. The enhancement of chromatographic analysis of beer oligosaccharides using solid-phase extraction.

    Czech Academy of Sciences Publication Activity Database

    ?melík, Richard; Žídková, Jitka; Bobálová, Janette

    Poznan : Poznan University of Life Sciences, 2010 - (Zió?kowska, A.). s. 144 [International Symposium on Advances in Extraction Technologies /12./. 20.09.2010-22.09.2010, Pozna?] R&D Projects: GA MŠk 2B06037 Institutional research plan: CEZ:AV0Z40310501 Keywords : oligosaccharides * SPE * beer Subject RIV: CB - Analytical Chemistry, Separation

  6. Determination of herbicides by solid phase extraction gas chromatography-mass spectrometry in drinking waters

    OpenAIRE

    SARZANINI, Corrado; Bruzzoniti, Maria Concetta

    2006-01-01

    Asolid phase extraction (SPE) method has been optimized for the gas chromatography–mass spectrometry (GC–MS) simultaneous determination of herbicides belonging to the following different families: carbamate (molinate), atrazines (atrazine, propazine, simazine, ametryne, cyanazine, terbutylazine, deethylterbutylazine, deethylatrazine), dinitroaniline (trifluralin, pendimethalin), chloroacetamide (alachlor, metolachlor). Different solid substrates have been compared (C18, cyano, styren...

  7. Simultaneous extraction of tetracycline, macrolide and sulfonamide antibiotics from agricultural soils using pressurised liquid extraction, followed by solid-phase extraction and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Jacobsen, Anne Marie; Halling-Sørensen, Bent; Ingerslev, Flemming; Hansen, Steen Honoré

    2004-06-01

    The veterinary antibacterial agents chlortetracycline (CTC), oxytetracycline (OTC), sulfadiazine (SDZ), erythromycin (ERY) and tylosin (TYL A, B, C and D) were extracted from soil using pressurized liquid extraction (PLE). Citric acid (pH 4.7) and methanol was used as extraction buffer, followed by tandem-solid-phase extraction (SPE) clean-up (SAX + HLB) for all compounds. For quantification two slightly different methods were employed using LC-MS-MS with MRM detection. The soil extraction method was validated using a loamy sand soil and a sandy soil, representing two typical Danish agricultural soils. Recoveries were 50-80% for the tetracyclines (CTC and OTC) and sulfadiazine (SDZ) and 60-100% for the macrolides (TYL and ERY). Limits of detection for the soil extraction method (LOD(soil)) were 0.6-5.6 microg kg(-1) soil for CTC and OTC, 0.9-2.9 microg kg(-1) soil for SDZ and 2.4-5.5 microg kg(-1) soil for TYL A and ERY. Furthermore, the method was applied to field samples taken from two agricultural fields fertilised with liquid manure containing CTC and TYL A. These results showed a decline in the content of antibacterial agents throughout the sampling period of 155 days from 10 to 15 microg CTC kg(-1) soil and 20-55 microg TYL A kg(-1) soil to below or near the LOD(soil) listed above. Finally, the method was applied to barley grains harvested from the fields. None of the antibacterial agents were measured in grain samples, but recoveries for spiked grain samples were similar to soil recoveries. PMID:15233531

  8. Head Space Solid Phase Micro-Extraction (HS - SPME of volatile organic compounds produced by Sporidiobolus salmonicolor (CBS 2636

    Directory of Open Access Journals (Sweden)

    Eunice Valduga

    2010-12-01

    Full Text Available The aim of the present study was the assessment of volatile organic compounds produced by Sporidiobolus salmonicolor (CBS 2636 using methyl and ethyl ricinoleate, ricinoleic acid and castor oil as precursors. The analysis of the volatile organic compounds was carried out using Head Space Solid Phase Micro-Extraction (HS - SPME. Factorial experimental design was used for investigating extraction conditions, verifying stirring rate (0-400 rpm, temperature (25-60 ºC, extraction time (10-30 minutes, and sample volume (2-3 mL. The identification of volatile organic compounds was carried out by Gas Chromatography with Mass Spectrum Detector (GC/MSD. The conditions that resulted in maximum extraction were: 60 ºC, 10 minutes extraction, no stirring, sample volume of 2.0 mL, and addition of saturated KCl (1:10 v/v. In the bio-production of volatile organic compounds the effect of stirring rate (120-200 rpm, temperature (23-33 ºC, pH (4.0-8.0, precursor concentration (0.02-0.1%, mannitol (0-6%, and asparagine concentration (0-0.2% was investigated. The bio-production at 28 ºC, 160 rpm, pH 6,0 and with the addition of 0.02% ricinoleic acid to the medium yielded the highest production of VOCs, identified as 1,4-butanediol, 1,2,2-trimethylciclopropilamine, beta-ionone; 2,3-butanodione, pentanal, tetradecane, 2-isononenal, 4-octen-3-one, propanoic acid, and octadecane.

  9. Selective solid-phase extraction of urinary 2,3-dinor-6-ketoprostaglandin F1 alpha for determination with radioimmunoassay.

    Science.gov (United States)

    Riutta, A; Nurmi, E; Weber, C; Hansson, G; Vapaatalo, H; Mucha, I

    1994-08-01

    This paper describes a method for selective two-step solid-phase extraction of urinary 2,3-dinor-6-ketoprostaglandin F1 alpha for reliable determination with radioimmunoassay. In the immunoreactivity profile of non-selectively extracted urine after HPLC separation, over 90% of the total 2,3-dinor-6-ketoprostaglandin F1 alpha immunoreactivity consisted of interfering material coeluting with 6-ketoprostaglandin F1 alpha and 2,3-dinor-6-ketoprostaglandin F1 alpha. Among the alkyl silica sorbents studied (methyl, butyl, octyl, and octadecyl), an efficient separation of 2,3-dinor-6-ketoprostaglandin F1 alpha from 6-ketoprostaglandin F1 alpha and the lowest immunoreactive concentration of analyte were achieved in extraction on the methyl silica sorbent by elution of 2,3-dinor-6-ketoprostaglandin F1 alpha with chloroform: hexane (85:15, v/v) from the cartridge. The proportion of specific immunoreactivity could be further increased by two-step extraction of sample on methyl silica cartridges, first at pH 3 and then at pH 10 using diethyl ether:hexane (85:15, v/v) and chloroform as eluent, respectively. After this, a high correlation was found with concentrations of samples determined by radioimmunoassay using three different antisera. A significant correlation of values was also observed between samples measured by radioimmunoassay and those measured by GC-MS. The values of 12-h excretion of 2,3-dinor-6-ketoprostaglandin F1 alpha in eight volunteers (268 +/- 204 ng/g creatinine, mean +/- SD) as well as the inhibitory effect of acetylsalicylic acid (74 +/- 12%) are in accordance with those reported in the literature. This selective extraction procedure provides a high validity in radioimmunoassay without requiring subsequent TLC or HPLC purification. PMID:7978278

  10. QUANTITATIVE DETERMINATION OF CHIRAL DICHLORPROP AND MECOPROP ENANTIOMERS IN DRINKING AND SURFACE WATERS BY SOLID-PHASE EXTRACTION AND CAPILLARY ELECTROPHORESIS.

    Czech Academy of Sciences Publication Activity Database

    T?íska, Jan; Vrchotová, Nad?žda

    2002-01-01

    Ro?. 11, ?. 7 (2002), s. 332-336. ISSN 1018-4619 Institutional research plan: CEZ:AV0Z6087904 Keywords : capillary electrophoresis * solid-phase extraction * chiral herbicides Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.309, year: 2002

  11. Determination of quinolone residues in infant and young children powdered milk combining solid-phase extraction and ultra-performance liquid chromatography–tandem mass spectrometry

    OpenAIRE

    Herrera-Herrera, Antonio V.; Hernández-Borges, Javier; Rodríguez-Delgado, Miguel A.; Herrero, Miguel; Cifuentes, Alejandro

    2011-01-01

    The present work describes a method based on solid-phase extraction (SPE) and ultra-performance liquid chromatography tandem mass spectrometry (UPLC–MS/MS) for the simultaneous determination of three quinolones (pipemidic acid, oxolinic acid and flumequine) and twelve fluoroquinolones (marbofloxacin, fleroxacin, pefloxacin, levofloxacin, norfloxacin, ciprofloxacin, enrofloxacin, danofloxacin, lomefloxacin, difloxacin, sarafloxacin, and moxifloxacin) in different infant and young children powd...

  12. Flame atomic absorption spectrometric (FAAS) determination of copper, iron and zinc in food samples after solid-phase extraction on Schiff base-modified duolite XAD 761

    Energy Technology Data Exchange (ETDEWEB)

    Ghaedi, M., E-mail: m_ghaedi@mail.yu.ac.ir [Chemistry Department, Yasouj University, Yasouj 75918-74831 (Iran, Islamic Republic of); Mortazavi, K. [Chemistry Department, Gachsaran Branch, Islamic Azad University, Gachsaran (Iran, Islamic Republic of); Montazerozohori, M. [Chemistry Department, Yasouj University, Yasouj 75918-74831 (Iran, Islamic Republic of); Shokrollahi, A. [Chemistry Department, Gachsaran Branch, Islamic Azad University, Gachsaran (Iran, Islamic Republic of); Soylak, M. [Chemistry Department, University of Erciyes, 38039 Kayseri (Turkey)

    2013-05-01

    The present study involves the development of solid-phase extraction (SPE) procedure for the preconcentration of trace amounts of copper (Cu{sup 2+}), iron (Fe{sup 3+}) and zinc (Zn{sup 2+}) ions on duolite XAD 761 modified by bis(2-hydroxyacetophenone)-2,2-dimethyl-1,3-propanediimine(BHAPDMPDI). The complexation between the metal ions and the proposed ligand was investigated potentiometrically. The metal ions retained on the sorbent were quantitatively determined via complexation with BHAPDMPDI. The complexed metal ions were efficiently eluted using 6 mL of 4 mol L{sup ?1} nitric acid in acetone. The influences of the analytical parameters, including pH, amounts of the ligand and the solid phase, eluent conditions and sample volume, on the recoveries of the metal ions were optimized. Using the optimized parameters, the linear response of the SPE method for Cu{sup 2+}, Zn{sup 2+} and Fe{sup 3+} ions were in the ranges of 0.01–0.34, 0.01–0.28 and 0.02–0.31 ?g mL{sup ?1}, respectively, and the detection limits for Cu{sup 2+}, Zn{sup 2+} and Fe{sup 3+} ions were 1.8, 1.6 and 2.4 ?g mL{sup ?1}, respectively. The proposed method exhibits a preconcentration factor of 208 for all of the ions studied and an enhancement factor for Cu{sup 2+}, Fe{sup 3+} and Zn{sup 2+} ions of 34, 28 and 38, respectively. The presented results demonstrate the successful application of the proposed method for the determination of these metal ions in some real samples with high recoveries (> 95%) and reasonable relative standard deviation (RDS < 5%). Highlights: ? Highly efficient adsorbent for dye removal was synthesized. ? The sorbent was fully characterized. ? The proposed method has a potential of a waste water treatment alternative. ? Excellent properties of the sorbent have been illustrated in detail.

  13. Solid phase extraction and reversed-phase high performance liquid chromatography of homidium in animal tissues

    International Nuclear Information System (INIS)

    Homidium bromide, an antitrypanosomal drug, has been in use for about 40 years both for chemotherapy and limited chemoprophylaxis but no specific and accurate method for its detection at sub-microgram levels in tissues is available. The HPLC method described uses C18 reversed phase analytical column with UV detection after basic sample extraction and clean-up on a 3 ml cyano Bond Elut disposable extraction column. Drug recoveries of up to 80% were obtained in the extracts. All tissues analysed were from animals treated with 14C labelled homidium at a dose of 1 mg/kg body weight and slaughtered at 14, 21 and 28 days after treatment. Recoveries were determined by comparing radiometric and HPLC results. The advantage of this procedure was that large amounts of samples could be processed especially from tissues with low drug levels. The detection limit was 50 ng per gram wet tissue. This method is simple, fast, accurate and sufficiently sensitive to be used for monitoring drug levels in meat destined for human consumption. (author). 3 refs, 4 figs, 6 tabs

  14. [Determination of 11 triazole fungicides in fruits using solid phase extraction and gas chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Li, Jige; Wang, Yufei; Shi, Jiawei; Jiang, Li; Yao, Xunping; Fang, Lanyun

    2012-03-01

    A method was developed and validated for the simultaneous determination of 11 triazole fungicides (tetraconazole, triflumizole, penconazole, hexaconazole, flutriafol, myclobutanil, etuconazole, propiconazole, tebuconazole, epoxiconazole and fluquinconazole) in fruits by gas chromatography-tandem mass spectrometry (GC-MS/MS). The triazole fungicides were extracted from the samples with acetonitrile, then enriched and cleaned-up with solid phase extraction (SPE) on a Carbon/NH2 cartridge (collecting 2 - 10 mL effluent). The detection was carried out by GC-MS/MS in the multiple reaction monitoring (MRM) mode, and the quantification analysis was performed by external standard method. The calibration curves showed good linearity in the range of 10 - 500 microg/L. The correlation coefficients were larger than 0. 994 0. The average recoveries of the 11 fungicides spiked in the fruits at the levels of 10, 50, 100 and 250 microg/kg were between 82.6% and 117.1%, and the relative standard deviations (RSD) were less than 10%. The limits of quantification (S/N = 10) were between 0.8 microg/kg and 3.4 microg/kg. The method possesses low background, high sensitivity, and quantification limits lower than that of the national standard and the values reported in the relevant literature. It can be applied to the routine analysis of the 11 triazole fungicides in fruits. PMID:22715691

  15. Determination of Benzo(a)pyrene in Malaysian commercialized coffee powder using solid phase extraction and gas chromatography

    International Nuclear Information System (INIS)

    Roasting is a critical process in coffee production as it enables the development of flavor and aroma. Benzo[a]pyrene (BaP) is a non desirable product of incomplete combustion at temperatures between 300 and 600 degree Celsius and may be produced during roasting step. In this study, selected samples of roasted coffee powder were analysed for BaP. Extraction of BaP was achieved using C18 solid phase extraction (SPE) prior to analysis by gas chromatography. Calibration curve prepared with concentrations ranged between 3 - 50 ppm showed good linearity with r = 0.999. The limit of detection (LOD) was 0.25 ppm and the limit of quantification (LOQ) was 0.85 ppm. Recovery of BaP obtained from spiked sample (3 ppm) was 88.7 % with RSD (n=3) of 5.4 %. Benzo[a]pyrene was detected in all samples, at level ranging from 0.14 to 0.62 ppb. (author)

  16. Determination of low levels of lead in beer using solid-phase extraction and detection by flame atomic absorption spectrometry.

    Science.gov (United States)

    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) HNO(3) 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??g?L(-1), n = 7), 7.5??g?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

  17. Valuation of solid phase extraction disks in the determination of pesticide residues in surface and groundwater in Panama

    International Nuclear Information System (INIS)

    In Panama large quantities of pesticides are used in agriculture and livestock farming and there is increasing concern about their impact on public health and the environment. Chiriqui is the Province that registers the largest number of producers whose activities have impact on the environment, especially on surface and groundwater. Systematic monitoring programmes are non-existent due, in part, to the high cost of laboratory determination of environmental residues of pesticides. Within the framework of the FAO/IAEA/SIDA Coordinated Research Programme, efforts were focused on evaluating and optimising the use of solid phase extraction C18 membrane disks in the analysis of surface and groundwater samples to determine pesticide residues. Factors studied were the effect of pre-washing and conditioning of the disks, flow rates, concentration level and matrix effects of field samples. Four pesticides, carbofuran, chlorothalonil, ametryn and chlorpyrifos were selected for these tests because preliminary analysis showed their presence in surface and groundwater. The technique significantly reduces the amount of organic solvents used as compared with the liquid-liquid extraction method. Quantifiable detection limits (QL) for the method were found to be 0.003 ?g/L carbofuran, 0.016 ?g/L chlorothalonil, 0.007 ?g/L ametryn and 0.003 ?g/L chlorpyrifos, when using standard spiked solutions. Recovery (%) was high when standard mixtures were used for the test runs but low when real surface water samples were tested, especially for chlorothalonil which was not recovered at all. (author)

  18. Determination of Chlorophenols in Water Samples Using Solid-Phase Extraction Enrichment Procedure and Gas Chromatography Analysis.

    Science.gov (United States)

    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

  19. Determination of Triclosan and Ketoprofen in River Water and Wastewater by Solid Phase Extraction and High Performance Liquid Chromatography

    Scientific Electronic Library Online (English)

    Lawrence M., Madikizela; Sindisiwe F., Muthwa; Luke, Chimuka.

    2014-01-01

    Full Text Available This paper describes a simple, sensitive and rapid method for the determination of triclosan and ketoprofen in wastewater influent, effluent and river water. The method involves solid phase extraction (SPE) of target compounds using Oasis HLB sorbent. Several extraction parameters such as sample pH, [...] sample volume, SPE cartridge and SPE elution solvent were optimized. The pH of the collected samples was adjusted to 5.5, and then 100 mL of the sample was loaded into an Oasis HLB cartridge. Methanol was used to elute the retained compounds. The eluted compounds were analyzed using reversed-phase high performance liquid chromatography with photo diode array detection (HPLC-PDA). The method was validated by spiking ultra-pure water and wastewater with different concentrations of both compounds ranging from 5 ju,g L-1 to 1000ju,g L-1. Recoveries were in the range of 73 % to 104 %, and % RSD ranged from 8%to15%. The method gave good detection limits of 0.01 and 0.08 ju,g L-1 for triclosan and ketoprofen, respectively. Traces of both compounds were detected in all wastewater (influent and effluent) samples at a range of 1.2 to 9.0 ju,g L-1 and in some river water samples.

  20. DETERMINATION OF MUSHROOM TOXIN ALPHA-AMANITIN IN SERUM BY LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY AFTER SOLID-PHASE EXTRACTION

    Directory of Open Access Journals (Sweden)

    Maja Vujovi?

    2015-03-01

    Full Text Available Alpha-amanitin is a cyclic peptide which belongs to a large group of mushroom toxins known as amatoxins. Being responsible for the majority of fatal mushroom poisonings, they require rapid detection and excretion from the body fluids. In accordance with these requirements, a simple and an accurate method was developed for successful identification and quantification of alpha-amanitin in serum with electrospray liquid chromatography–mass spectrometry (LC-ESI-MS after collision-induced dissociation. The method conforms to the established International Conference on Harmonization Q2A/Q2B 1996 guidelines on the validation of analytical methods. Linearity, precision, extraction recovery and stability test on blank serum spiked with alpha-amanitin and stored in different conditions met the acceptance criteria. The obtained calibration curve was linear over the concentration range 5-100 ng/mL with a lower limit of quantification (LOQ of 5 ng/mL and limit of detection (LOD of 2.5 ng/mL. The mean intra- and inter-day precision and accuracy were 6.05% and less than ±15% of nominal values, respectively. The neutral solid phase extraction with copolymer hydrophilic–lipophilic balance cartridges was found optimal for sample preparation with the mean recovery of 91.94%. The proposed method demonstrated high sensitivity and selectivity which can be useful both for clinical and forensic toxicology analysis of alpha-amanitin at low concentrations.

  1. Screening for Anabolic Steroids in Urine of Forensic Cases Using Fully Automated Solid Phase Extraction and LC–MS-MS

    DEFF Research Database (Denmark)

    Andersen, David Wederkinck; Linnet, Kristian

    2014-01-01

    A screening method for 18 frequently measured exogenous anabolic steroids and the testosterone/epitestosterone (T/E) ratio in forensic cases has been developed and validated. The method involves a fully automated sample preparation including enzyme treatment, addition of internal standards and solid phase extraction followed by analysis by liquid chromatography-tandem mass spectrometry (LC-MS-MS) using electrospray ionization with adduct formation for two compounds. Urine samples from 580 forensic cases were analyzed to determine the T/E ratio and occurrence of exogenous anabolic steroids. Extraction recoveries ranged from 77 to 95%, matrix effects from 48 to 78%, overall process efficiencies from 40 to 54% and the lower limit of identification ranged from 2 to 40 ng/mL. In the 580 urine samples analyzed from routine forensic cases, 17 (2.9%) were found positive for one or more anabolic steroids. Only seven different steroids including testosterone were found in the material, suggesting that only a small number of common steroids are likely to occur in a forensic context. The steroids were often in high concentrations (>100 ng/mL), and a combination of steroids and/or other drugs of abuse were seen in the majority of cases. The method presented serves as a fast and automated screening procedure, proving the suitability of LC-MS-MS for analyzing anabolic steroids.

  2. Validation of a solid phase extraction technique for the determination of halogenated acetic acids in drinking water

    International Nuclear Information System (INIS)

    Halo acetic acids (HAAs) are one of the most common disinfection by-products formed during chlorination of drinking water. An analytical method involving solid phase extraction (SPE) followed by gas-chromatograph mass-spectrometry (GC-MS) was developed and optimized using experimental design to determine the HAAs in water. Selectivity, percent recovery, and detection limit studies were carried out on a Silia-SAX (Trimethyl ammonium chloride) SPE. Under optimized conditions, average recoveries for nine HAAs spiked in drinking water samples range from 69.2 % to 108.2 %. The relative standard deviation (RSD) data were found to range from 2.5 % to 12.5 % based upon five repeat recovery experiments and detection limit range of 0.16 to 0.009 ?g/ l were obtained. On this basis, SPE was studied as a possible alternative to liquid-liquid extraction (LLE) for the analysis of HAAs in water. The performance of the SPE-GC-MS with actual water samples was tested. (author)

  3. Magnetic solid-phase extraction for determination of sulpiride in human urine and blood using high-performance liquid chromatography.

    Science.gov (United States)

    Zhao, Jiao; Liao, Wenlong; Yang, Yaling

    2015-12-01

    A novel and efficient sample preconcentration technique based on the Fe3 O4 magnetic nanoparticles (Fe3 O4 MNPs) coated with silica (SiO2 ) has been developed for extraction and determination of sulpiride. The functionalized MNPs showed excellent dispersibility in aqueous solution and were applied to magnetic solid-phase extraction of sulpiride from human urine and blood prior to high-performance liquid chromatography analysis. The separation, preconcentration and desorption procedure was completed in 10?min. Optimal experimental conditions, including sample pH, the amount of the MNPs, eluent type and volume, and the ultrasonication time were studied and established. The method showed good linearity for the determination of sulpiride in the concentration range of 10-1000?ng/mL in urine and blood. The recovery of the method was in the range between 91.2 and 97.5%, and the limit of detection was 2?ng/mL for sulpiride in human blood and urine. The results indicated that the present procedure is a suitable pretreatment method for biological samples. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26019021

  4. Application of microwave-assisted micro-solid-phase extraction for determination of parabens in human ovarian cancer tissues.

    Science.gov (United States)

    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 (?-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 ?-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

  5. Colourimetric solid-phase extraction coupled with fibre optic reflectance spectroscopy for determination of ascorbic acid in pharmaceutical formulations.

    Science.gov (United States)

    Filik, Hayati; Aksu, Duygu; Giray, Derya; Apak, Re?at

    2012-06-01

    A redox colourimetric solid-phase extraction (C-SPE) procedure for the determination of ascorbic acid (AA) in pharmaceutical formulations was proposed. Iron (III)-2,2'-dipyridyl (Fe(III)-Bpy) reagent solution was used as a colouring reagent for AA and the immobilization of the redox product onto Amberlite XAD-16 resin was achieved. The analyte in the sample reacted with a solid sorbent loaded with the colourimetric reagent (Fe(III)-Bpy) and then quantified directly on the sorbent surface by using a fibre optic reflectance spectrometer (FORS). The amount of AA was reflectometrically determined in a few seconds with a total sample workup and readout time of ?10 min using only 10-ml sample volumes. The limit of detection (LOD) and quantification (LOQ) values were 0.18 and 0.6 mg L(-1), respectively, and the linear dynamic range for AA extended up to 8.8 mg L(-1). The C-SPE for different extractions (n = 5) gave a relative standard deviation (RSD) of 2.9% at 5.28 mg L(-1) AA level. PMID:21337723

  6. Use of Pollen Solid-Phase Extraction for the Determination of trans-Resveratrol in Peanut Oils.

    Science.gov (United States)

    Lu, Qian; Zhao, Qin; Yu, Qiong-Wei; Feng, Yu-Qi

    2015-05-20

    In this study, a simple and convenient method for the determination of trans-resveratrol (TRA) in peanut oils based on pollen grain solid-phase extraction (SPE) was developed. Pollen grains were used as normal-phase SPE sorbent to separate TRA from peanut oils for the first time. As a naturally occurring material, pollen grains exhibited an excellent adsorption capacity for polyphenolic compounds due to their particular functional structures such as hydroxyl groups, saturated and unsaturated aliphatic chains with aromatics. Their stable compositions as well as adequate particle size (30-40 ?m) also make them suitable for SPE. Several parameters influencing extraction performance were investigated. Coupled with high-performance liquid chromatography-ultraviolet detection (HPLC-UV), a green purification method for fast determination of TRA in peanut oils using pollen grain cartridges as sorbents was established. The linearity range of the proposed method was 10-2500 ng · g(-1) with a satisfactory correlation coefficient (r(2)) of 0.9999. The limit of detection (LOD) for TRA in peanut oils was 2.7 ng · g(-1), and the recoveries in spiked oil samples were from 70.2% to 98.4% with the relative standard deviations (RSDs) less than 4.9% (intraday) and 5.2% (interday). This method was successfully applied to the analysis of TRA in several peanut oils with different brands from local market as well as other kinds of vegetable oils. PMID:25915548

  7. Solid-phase microextraction

    DEFF Research Database (Denmark)

    Nilsson, Torben

    1997-01-01

    The objective of this study has been to develop new analytical methods using the rapid, simple and solvent-free extraction technique solid-phase microextraction (SPME) for the quantitative analysis of organic pollutants at trace level in drinking water and environmental samples. The dynamics of SPME were examined for halogenated and non-halogenated volatile hydrocarbons, and a standard method for their quantitative analysis in aqueous samples was developed and validated in inter-laboratory studi...

  8. Sol-gel-based silver nanoparticles-doped silica - Polydiphenylamine nanocomposite for micro-solid-phase extraction.

    Science.gov (United States)

    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 (?-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 ?g L(-1) and 0.1-0.2 ?g 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

  9. Determination of fungicides in wine by mixed-mode solid phase extraction and liquid chromatography coupled to tandem mass spectrometry.

    Science.gov (United States)

    Carpinteiro, I; Ramil, M; Rodríguez, I; Cela, R

    2010-11-26

    A novel procedure for the determination of nine selected fungicides (metalaxyl-M, azoxystrobin, myclobutanil, flusilazole, penconazole, tebuconazole, propiconazole, diniconazole and difenoconazole) in wine samples is presented. Sample enrichment and purification is simultaneously performed using mixed-mode, anion exchange and reversed-phase, OASIS MAX solid-phase extraction (SPE) cartridges. Analytes were determined by liquid chromatography coupled to tandem mass spectrometry using atmospheric pressure electrospray ionization (LC-ESI-MS/MS). Parameters affecting the chromatographic determination and the extraction-purification processes were thoroughly investigated. Under optimized conditions, 10 mL of wine were firstly diluted 1:1 with ultrapure water and then passed through the mixed-mode SPE cartridge at a flow of ca. 5 mLmin(-1). After a washing step with 5 mL of an aqueous NH(4)OH solution (5%, w:v), analytes were recovered with just 1 mL of methanol and injected in the LC-MS/MS system without any additional purification. The selective extraction process avoided significant changes in the ionization efficiency for red and white wine extracts in comparison with pure standards in methanol. Performance of the method was good in terms of precision (RSDs72%, determined against pure standards in methanol) reporting method LOQs in the range of 0.01-0.79 ngmL(-1) for target compounds, which are far below the EU maxima residue levels (MRLs) for fungicides in vinification grapes and wine. Several commercial wines from different geographic areas in Spain were analyzed. In most samples, metalaxyl-M and azoxystrobin were found at concentrations up to several ngmL(-1). PMID:20971470

  10. Characteristic of New Solid-Phase Extraction Sorbent: Activated Carbon Prepared from Rice Husks under Base Treated Condition

    Directory of Open Access Journals (Sweden)

    Afrida Kurnia Putri

    2012-10-01

    Full Text Available A characterization of activated carbon (ACs prepared from rice husks (RHs under base treated condition as a new sorbent for solid-phase extraction (SPE to extract 4-nonylphenol isomers (4-NPs in water samples has been done. The ACs prepared from RHs usually exhibits low specific surface area due to its high ash content, but in case of its application for SPE, there are other factors need to be considered, such as the existence of functional groups inside the sorbent, that can enhance interaction of non-polar sorbent with analyte in the water matrices. In this case, silanol groups from ash content may affect the extraction efficiency for 4-NPs. The ACs made from RHs were chemically impregnated with ZnCl2 and carbonized at 800oC. To investigate the role of silica, three types of ACs were prepared, i.e., untreated ACs (AC–Si, contain silica, base treated ACs (AC–B–Si, remain some silica inside, and ACs made by base treated RHs (AC–B, no silica, the surface area obtained from these treatments were 1352 m2/g, 1666 m2/g, and 1712m2/g respectively.  ACs made by base treatment has the highest surface area (related to BET, which indicat that silica removal process promotes the formation of open pore system on ACs and enhances the surface area of ACs. However, extraction efficiency measured by GC-MS in SPE process showed the reversal trends (i.e., AC–Si= 32.08%, AC–B–Si= 82.63%, AC–B=51.78%, among them the AC–B–Si sorbent reveal the best performance in SPE process. It is indicated that although silica usually exhibits low specific surface area, but control presence of silica as a polar functional group has a positive influence in the interaction between non-polar sorbent and 4-NPs.

  11. Solid phase extraction and spectrophotometric determination of mercury in tobacco and tobacco additives with 5-(p-aminobenzylidene)-thiothiorhodanine

    Scientific Electronic Library Online (English)

    Weizhu, Yang; Qun, Hu; Jing, Ma; Liming, Wang; Guangyu, Yang; Gang, Xie.

    2006-10-01

    Full Text Available Foi desenvolvido um método altamente sensível, seletivo e rápido para a determinação de mercúrio, a partir da reação rápida de mercúrio(II) com 5-(p-aminobenzilideno)-tiorodanina (ABTR) e posterior extração em fase sólida do quelato colorido, utilizando discos C18. Em pH 3,5 e na presença do emulsif [...] icante-OP, ABTR reage com mercúrio(II) para formar um quelato vermelho na razão molar 1:2 (mercúrio:ABTR). O quelato foi enriquecido pela extração em fase sólida com discos C18 e o quelato retido, eluído com dimethyl formamida (DMF). Um fator de enriquecimento na ordem de 50 foi obtido. Em DMF, a absortividade molar do quelato é 1,21´10(5) L mol-1 cm-1 a 545 nm, e a lei de Beer é obedecida no intervalo 0,01~3 µg mL-1 na solução medida. O desvio padrão relativo para onze replicatas a 0,01 µg mL-1 é 1,7%. Este método foi aplicado para a determinação de mercúrio em tabaco e aditivos de tabaco. Bom coeficiente de preconcentração foi encontrado, comparando-se o método proposto com outros similares. Abstract in english A highly sensitive, selective and rapid method for the determination of mercury based on the rapid reaction of mercury(II) with 5-(p-aminobenzylidene)-thiorhodanine (ABTR) and the solid phase extraction of the colored chelate with C18 disks has been developed. At pH 3.5 and in the presence of emulsi [...] fier-OP medium, ABTR reacts with mercury(II) to form a red chelate of a 1:2 (mercury to ABTR) molar ratio. This chelate was enriched by solid phase extraction with C18 disks and the retained chelate eluted form the disks with dimethyl formamide (DMF). An enrichment factor of 50 was achieved. In the DMF medium, the molar absorptivity of the chelate is 1.21´10(5) L mol-1 cm-1 at 545 nm, and Beer's law is obeyed in the 0.01~3 µg mL-1 range in the measured solution. The relative standard deviation for eleven sample replicate measurements at the 0.01 µg mL-1 level is 1.7%. This method was applied to the determination of mercury in tobacco and tobacco additives and good preconcentration was found between proposed and comparative methods results.

  12. Solid phase extraction for determination of 90Sr in water sample

    International Nuclear Information System (INIS)

    We studied the use of an extraction chromatography for determination of 90Sr in samples of contaminated water. The aim of the thesis was to compare selected products from the point of view of the strontium yields and time needed. Three commercial products: 3M Empore Strontium Rad Disk, AnaLig, Sr-Resin and two classical methods: liquid-liquid extraction with tributylphosphate and carbonate co-precipitation (to eliminate interferers) were used for separation of 90Sr. The water sample was used in radiochemical analysis for determination volume activity of 90Sr. A radiochemical strontium yield was traced by using radionuclide 85Sr. Samples were counted over a two week period to monitor the ingrowth of 90Y on TRI CARB LSC counter. Samples were measured using an HPGe detector to find out 85Sr recoveries at 514 keV line and they were counted directly by Cherenkov counting after the growth of 90Y using TriCarb LSC counter after a two- week period (author)

  13. Thin film-XRF determination of uranium following thin-film solid phase extraction

    Scientific Electronic Library Online (English)

    Jalal, Hassan; Seyed M., Hosseini; Shahla, Mozaffari; Babak, Jahanparast; Mohammad H., Karbasi.

    2014-06-01

    Full Text Available Foi desenvolvido um método sensível baseado na pré-concentração de urânio em papel de filtro modificado (filme fino) para a determinação deste elemento em amostras de águas e de solos, usando a técnica de fluorescência de raios-X de comprimento de onda dispersivo. Para a extração de urânio (VI), 100 [...] mL de amostra reagiram com tri-octil fosfina (TOPO) em presença de ácido nítrico. O efeito da concentração de ácido nítrico e de TOPO, bem como da retenção do metal em função do volume de amostra foram avaliados neste estudo. O método proposto mostrou boa linearidade entre 7 e 1000 µg de urânio (VI) e o limite de detecção (LOD), calculado com a relação sinal-ruído (S/N) igual a 3 foi de 2,5 µg. Abstract in english A sensitive method based on the preconcentration of uranium on modified filter paper (thin film) has been developed to determinate this element in water and soil samples by wavelength dispersive X-ray fluorescence. Uranium (VI) extraction from nitric acid medium by trioctyl phosphine (TOPO) from 100 [...] mL of sample was carried out. The effects of nitric acid concentration, TOPO concentration and sample breakthrough on uranium extraction were investigated in this study. The proposed method provided good linearity from 7 to 1000 µg and the limit of detection (LOD), based on a signal-to noise ratio (S/N) of 3, was 2.5 µg.

  14. Facile magnetization of metal-organic framework MIL-101 for magnetic solid-phase extraction of polycyclic aromatic hydrocarbons in environmental water samples.

    Science.gov (United States)

    Huo, Shu-Hui; Yan, Xiu-Ping

    2012-08-01

    The unusual properties such as high surface area, good thermal stability, uniform structured nanoscale cavities and the availability of in-pore functionality and outer-surface modification make metal-organic frameworks (MOFs) attractive for diverse analytical applications. However, integration of MOFs with magnets for magnetic solid-phase extraction for analytical application has not been attempted so far. Here we show a facile magnetization of MOF MIL-101(Cr) for rapid magnetic solid-phase extraction of polycyclic aromatic hydrocarbons (PAHs) from environmental water samples. MIL-101 is attractive as a sorbent for solid-phase extraction of pollutants in aqueous solution due to its high surface area, large pores, accessible coordinative unsaturated sites, and excellent chemical and solvent stability. In situ magnetization of MIL-101 microcrystals as well as magnetic solid-phase extraction of PAHs was achieved simultaneously by simply mixing MIL-101 and silica-coated Fe(3)O(4) microparticles in a sample solution under sonication. Such MOF-based magnetic solid-phase extraction in combination with high-performance liquid chromatography gave the detection limits of 2.8-27.2 ng L(-1) and quantitation limits of 6.3-87.7 ng L(-1) for the PAHs. The relative standard deviations for intra- and inter-day analyses were in the range of 3.1-8.7% and 6.1-8.5%, respectively. The results showed that hydrophobic and ?-? interactions between the PAHs and the framework terephthalic acid molecules, and the ?-complexation between PAHs and the Lewis acid sites in the pores of MIL-101 play a significant role in the adsorption of PAHs. PMID:22695791

  15. Determination of 9alpha, 11beta prostaglandin F2 in human urine. combination of solid-phase extraction and radioimmunoassay.

    Science.gov (United States)

    Mucha; Riutta, A

    2001-01-01

    This paper describes a new iodine-125 radioimmunoassay of 9alpha ,11beta-PGF2, and its use for the determination of urinary 9alpha,11beta-prostaglandin F2 after a selective one-step solid-phase extraction. The newly reported immunoassay is based on the use of 125I-tyrosyl methyl ester derivative of 9alpha,11beta-PGF2 and specific polyclonal antibody raised in rabbits. The assay detected as lowas 0.85 pg/tube 9alpha,11beta-PGF2, and the antibodyshowed lessthan 0.01 cross-reaction with PGF-ring metabolites (e.g., 8-iso-PGF2alpha, PGF2alpha 2,3-dinor-6-keto-PGF1alpha, and 5 more PGF-ring compounds). Both the intra-assay, and inter-assay CVs were lessthan 20% for internal controls containing low, medium and high concentrations of 9alpha,11beta-PGF2. Immuno-HPLC analysis showed a very low ratio of specific immunoreactivity in both non-extracted urine (6.5%), and in urine extracted on C18-silicacartridge (14.8%). By contrast, approximately 80% specific immunoreactivity could be achieved by using C2-silicaas the sorbent, acetonitrile: water (15:85, v/v) as wash solvent, and ethyl acetate as eluent of 9alpha,11beta-PGF2. This extraction procedure enabled a reasonably high extraction efficiency of 80.4 +/- 0.855 (mean +/- SEM, n=82), as determined by 3H-9alpha,11beta-PGF2. The new SPE/RIA method was applied for the determination of urinary 9alpha,11beta-PGF2 values in 50 healthy human volunteers. For the concentration and for the excretion rate 37.52 +/- 4.61 pg/ml (mean +/- SEM), and 3.50 + 0.35 ng/mmol creatinine (mean +/- SEM), respectively, was measured. The specificity of the SPE/RIA method was supported by the observed 69% decrease in 9alpha, 11beta-PGF2 excretion rate after acetylsalicylic acid treatment. The effect of nicotinic acid, a PGD2-stimulatory agent, was monitored by the urinary excretion of 9alpha ,11beta-PGF2 in 6 patients, by using the new SPE/RIA method. In patients responding with flushing symptoms nicotinic acid induced an increase of the urinary excretion of 9alpha,11beta-PGF2 in the range between 11% and 187%. In summary, the combination of the newly developed specific [125I] radioimmunoassay with solid-phase extraction on C2-silica cartridges enables the specific, sensitive, and reliable determination of 9alpha,11beta-PGF2 in human urine without the need for further laborious chromatographic purification before radioimmunoassay. PMID:11993720

  16. Determination of [18F]FCWAY, [18F]FP-TZTP, and their metabolites in plasma using rapid and efficient liquid-liquid and solid phase extractions

    International Nuclear Information System (INIS)

    Liquid-liquid and solid phase extraction methods were developed for the accurate and rapid quantitation of radioactive components in human plasma following injection of two PET ligands. A solid phase extraction (SPE) method was developed for the determination of the 5HT1A receptor ligand [N-{2-[4-(2-methoxyphenyl) piperazino]ethyl}-N-(2-pyridinyl) trans-4-[18F]fluorocyclohexanecarboxamide (FCWAY), and its acidic metabolite, 4-[18F]fluorocyclohexane carboxylic acid (FC). In both cases, the extraction method was much faster and easier to use, yet provided results comparable to HPLC and TLC methods. In addition, an easy to perform two-step liquid-liquid extraction was developed for quantitation of 3-(3-((3-[18F]fluoropropyl)thio)-1,2,5-thiadiazol-4-yl)-1,2,5,6- tetrahydro-1-methylpyridine ([18F]FP-TZTP), a selective M2 muscarinic agonist

  17. Pesticide determination in rose petals using dispersive solid-phase extraction followed by gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    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

  18. Solid-phase extraction followed by dispersive liquid-liquid microextraction for the sensitive determination of selected fungicides in wine.

    Science.gov (United States)

    Montes, R; Rodríguez, I; Ramil, M; Rubí, E; Cela, R

    2009-07-17

    A novel approach for the determination of seven fungicides (metalaxyl-M, penconazole, folpet, diniconazole, propiconazole, difenoconazole and azoxystrobin) in wine samples is presented. Analytes were extracted from the matrix and transferred to a small volume of a high density, water insoluble solvent using solid-phase extraction (SPE) followed by dispersive liquid-liquid microextraction (DLLME). Variables affecting the performance of both steps were thoroughly investigated (metalaxyl-M was not included in some optimisation studies) and their effects on the selectivity and efficiency of the whole sample preparation process are discussed. Under optimised conditions, 20 mL of wine were first concentrated using a reversed-phase sorbent and then target compounds were eluted with 1 mL of acetone. This extract was mixed with 0.1 mL of 1,1,1-trichloroethane (CH(3)CCl(3)) and the blend added to 10 mL of ultrapure water. After centrifugation, an aliquot (1-2 microL) of the settled organic phase was analyzed by gas chromatography (GC) with electron capture (ECD) and mass spectrometry (MS) detection. The method provided enrichment factors (EFs) around 200 times and an improved selectivity in comparison to use of SPE as single sample preparation technique. Moreover, the yield of the global process was similar for red and white wine samples and the achieved limits of quantification (LOQs) (from 30 to 120 ngL(-1) and from 40 to 250 ngL(-1), for GC-ECD and GC-MS, respectively) were low enough for the determination of target species in commercial wines. Among compounds considered in this work, metalaxyl-M and azoxystrobin were found in several wines at concentrations from 0.8 to 32 ngmL(-1). PMID:19501367

  19. Three Birds with One Fe3O4 Nanoparticle: Integration of Microwave Digestion, Solid Phase Extraction, and Magnetic Separation for Sensitive Determination of Arsenic and Antimony in Fish.

    Science.gov (United States)

    Jia, Yun; Yu, Huimin; Wu, Li; Hou, Xiandeng; Yang, Lu; Zheng, Chengbin

    2015-06-16

    An environmentally friendly and fast sample treatment approach that integrates accelerated microwave digestion (MWD), solid phase extraction, and magnetic separation into a single step was developed for the determination of arsenic and antimony in fish samples by using Fe3O4 magnetic nanoparticles (MNPs). Compared to conventional microwave digestion, the consumption of HNO3 was reduced significantly to 12.5%, and the digestion time and temperature were substantially decreased to 6 min and 80 °C, respectively. This is largely attributed to Fe3O4 magnetic nanoparticles being a highly effective catalyst for rapid generation of oxidative radicals from H2O2, as well as an excellent absorber of microwave irradiation. Moreover, potential interferences from sample matrices were eliminated because the As and Sb species adsorbed on the nanoparticles were efficiently separated from the digests with a hand-held magnet prior to analysis. Limits of detection for arsenic and antimony were in the range of 0.01-0.06 ?g g(-1) and 0.03-0.08 ?g g(-1) by using hydride generation atomic fluorescence spectrometry, respectively, and further improved to 0.002-0.005 ?g g(-1) and 0.005-0.01 ?g g(-1) when inductively coupled plasma mass spectrometry was used as a detector. The precision of replicate measurements (n = 9) was better than 6% by analyzing 0.1 g test sample spiked with 1 ?g g(-1) arsenic and antimony. The proposed method was validated by analysis of two certified reference materials (DORM-3 and DORM-4) with good recoveries (90%-106%). PMID:25962876

  20. Determination of pinocembrin in human plasma by solid-phase extraction and LC/MS/MS: application to pharmacokinetic studies.

    Science.gov (United States)

    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??L 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

  1. Selective determination of trace 17?-estradiol in dairy and meat samples by molecularly imprinted solid-phase extraction and HPLC.

    Science.gov (United States)

    Shi, Yun; Peng, Dong-Dong; Shi, Chang-Hua; Zhang, Xia; Xie, Ya-Ting; Lu, Bin

    2011-06-15

    Molecularly imprinted solid-phase extraction (MISPE) combined with HPLC were used to detect trace 17?-estradiol (E2) in different dairy and meat samples. E2 imprinted mono-dispersed microspheres prepared by modified precipitation polymerisation method were used as MISPE sorbents. Under optimum MISPE and HPLC conditions, trace (0.116-0.461nmolkg(-1)) E2 in different dairy and meat samples can be detected accurately using UV detector when large amount of sample (500g) was analysed. Recoveries of E2 from spiked (0.1-5nmolkg(-1)) milk, yogurt, beef, pork and chicken were higher than 74.18%, 71.92%, 67.21%, 64.20% and 65.93%, respectively with RSDs less than 8.38%. MISPE can enrich E2 selectively, which is helpful to have better HPLC separation and higher recoveries than C18 SPE. MISPE combined with HPLC-UV are reliable methods to determine trace E2 in dairy and meat samples with high accuracy and repeatability. PMID:25213977

  2. Surfacted ferrofluid based dispersive solid phase extraction; a novel approach to preconcentration of cationic dye in shrimp and water samples.

    Science.gov (United States)

    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 ?g L(-1), and the preconcentration factor is 135. PMID:25952885

  3. Colorimetric-Solid Phase Extraction Technology for Water Quality Monitoring: Evaluation of C-SPE and Debubbling Methods in Microgravity

    Science.gov (United States)

    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.

  4. Optimization of Solid Phase Extraction for Trace Determination of Cobalt (II Using Chromosorb 102 in Biological Monitoring

    Directory of Open Access Journals (Sweden)

    Seyed Jamaleddin Shahtaheri

    2010-01-01

    Full Text Available Cobalt is widely used in different industrial processes for production of various synthetic materials. For assessment of human exposure to toxic metal of Co (II, environmental and biological monitoring are essential processes, in which, preparation of samples is one of the most time-consuming and error-prone aspects prior to instrumental analysis. The aim of this study was to achieve optimum factors necessary for development of a sample preparation technique for cobalt (II, present in urine, hair, and nail samples followed by atomic absorption spectrometry. Solid phase extraction (SPE using mini columns filled with Chromosorb 102 resin was optimized regarding sample pH, ligand concentration, loading flow rate, elution solvent, sample volume (up to 500 ml, elution volume, amount of resins, and sample matrix interferences. Cobalt ion was retained on sorbent and was eluted with 2 M HNO3 followed by determination by flame atomic absorption spectrometry. Obtained recoveries of cobalt ion were more than 92%. To evaluate occupational exposure to Co (II, successful applicability of the optimized method for human exposure was used by treatment real samples, including urine, hair, and nail. Suitable results were obtained for relative standard deviation (less than 10%. This optimized method can be considered successful in simplifying sample preparation for trace residue analysis of Co (II in different matrices when an evaluation of occupational and environmental exposures is required.

  5. New practical algorithm for modelling analyte recovery in bioanalytical reversed phase and mixed-mode solid phase extraction.

    Science.gov (United States)

    Hendriks, G; Uges, D R A; Franke, J P

    2008-09-10

    Solid phase extraction (SPE) is a widely used method for sample cleanup and sample concentration in bioanalytical sample preparation. A few methods to model the retention behaviour on SPE cartridges have been described previously but they are either not applicable to ionised species or are not suitable when using multiple wash and elution steps with solvents differing in volume, modifier concentration and acidity. Furthermore, these models were not applied to mixed mode SPE sorbents. In order to overcome these limitations a new SPE modelling algorithm was proposed. The retention behaviour was determined directly on the SPE cartridge by connecting the cartridge online with an HPLC system using a simple but suitable device that was developed and described. The results from these online experiments were used to model the elution behaviour using a quadratic retention function combined with an exponentially modified Gaussian peak shape model to predict analyte recovery under different wash and elution conditions. The validity of the proposed algorithm was tested using practical SPE experiments with an aqueous test mixture as well as with spiked human plasma. Different sequential wash and elution steps were performed using solvents differing in volume and composition. The predicted band shape and recoveries in each collected step were in good agreement with the results obtained from practical experiments. The proposed algorithm is very useful for the description of the SPE behaviour of the analytes on the actual used SPE cartridge and can be used in structural and automated SPE method development. PMID:18579329

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

    DEFF Research Database (Denmark)

    Fromberg, Arvid; HØjgård, A.

    2007-01-01

    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 mu g kg(-1)), except for one sample of sunflower oil containing 11 mu g kg(-1) benzo[a]pyrene.

  7. Simultaneous Determination of Tin, Nickel, Lead, Cadmium and Mercury in Cigarette Material by Solid Phase Extraction and HPLC

    International Nuclear Information System (INIS)

    A new method for the simultaneous determination of heavy metal ions in cigarette material by microwave digestion and reversed-phase high-performance liquid chromatography (RP-HPLC) has been developed. The cigarette material was digested by microwave digestion. Lead, cadmium, mercury, nickel and tin ions in the digested samples were pre-column derivatized with tetra-(2-chlorophenyl)-porphyrin (T2-CPP) to form color chelates, which were then enriched by solid phase extraction with a C18 cartridge. The chelates were separated on a Waters XterraTM RP18 column by gradient elution with methanol (containing 0.05 mol/L pyrrolidine-acetic acid buffer salt, pH = 10.0) and acetone (containing 0.05 mol/L pyrrolidine-acetic acid buffer salt, pH = 10.0) as mobile phase at a flow rate of 0.5 mL/min and analyzed with a photodiode array detector from 350-600 nm. The detection limits of lead, cadmium, mercury, nickel and tin were 4, 3, 3, 8, and 5 ng/L, respectively, in the original samples. This method was afforded good results

  8. Quantitative determination of oil films/slicks from water surfaces using a modified solid-phase extraction (SPE) sampling method

    International Nuclear Information System (INIS)

    A method to quantify oil films and slicks floating on water surfaces has been developed using a modified solid-phase extraction (SPE) procedure using C-18 disks. SPE is a commonly used method for isolating hydrophobic organic compounds from aqueous solutions in preparation for analysis. The objective of the study was to determine if surface sampling of oil slicks using this procedure is linear, precise and consistently yields quantitative recoveries of oil per unit area. The effectiveness of oil removal from a sandy beach in meso-scale wave tanks using different shoreline cleaner products was also assessed. Nine oil loadings were sampled with C18-SPE disks in replicates from the surface of 1 litre beakers. The results of these controlled laboratory experiments indicated that the sampling efficiency was strongly linear over the whole range tested, the variability was below 10 per cent and the oil was collected by the SPE disks in a 1:1 ratio relative to the water surface loadings. It was concluded that this method is a promising means by which to quantify and identifying oils present in meso-scale to large-scale slick in both experimental and natural settings. 17 refs., 1 tab., 3 figs

  9. Iodination on Tyrosine Residues During Oxidation with Sodium Periodate in Solid Phase Extraction of N-linked Glycopeptides

    Science.gov (United States)

    Cohen, Alejandro M.; Kostyleva, Ripsik; Chisholm, Kenneth A.; Pinto, Devanand M.

    2012-01-01

    Solid-phase extraction of N-linked glycopeptides (SPEG) using hydrazide-modified supports has become a common sample preparation procedure in glycoproteomic experiments. We demonstrate that iodination of tyrosine residues occur in SPEG as a side reaction during an oxidation step with sodium periodate. MS/MS analysis of oxidized bovine serum albumin and carbonic anhydrase digests revealed a characteristic shift of m/z 125.9 on all y and b fragment ions containing the modified tyrosine residues. Selected reaction monitoring (SRM) measurements showed that the peak intensity from of the iodinated peptides increased during the course of oxidation. After an hour of oxidation, SRM analysis revealed that the strongest signal from an iodinated peptide was approximately one-tenth of the intensity of the corresponding unmodified peptide. Iodinated tyrosine residues were also identified in serum samples subjected to SPEG and analyzed by LC-ESI-MS/MS. We recommend assessing this side reaction by including iodotyrosine as a variable modification when performing database searches on SPEG experiments. For SRM-based acquisitions, we encourage the avoidance of tyrosine-containing glycopeptides or, if this is not practical, monitoring transitions that contain the potential modified iodinated tyrosine residue to monitor the presence of the iodinated form of the glycopeptide.

  10. Simultaneous determination of herbicide residues in tobacco using ultraperformance convergence chromatography coupled with solid-phase extraction.

    Science.gov (United States)

    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

  11. Solid-phase microfibers based on modified single-walled carbon nanotubes for extraction of chlorophenols and organochlorine pesticides

    International Nuclear Information System (INIS)

    Solid-phase microextraction (SPME) based on carboxylated single-walled carbon nanotube fibers was used to extract several chlorophenols (CPs) and organochlorine pesticides (OCPs) from aqueous samples prior to their determination by GC with electron capture detection. The main parameters affecting microextraction (temperature, time, stirring rate and salting-out effect) and the conditions of the thermal desorption in the GC injector were optimized. Compared with commercial SPME fibers, the fiber presented better selectivity and sensitivity. Linear response was found for the concentration range between 2 and 1000 ng L-1 (20-1000 ng L-1 for CPs), and the limits of detection were in the range from 0.07 to 4.36 ng L-1. The repeatability expressed as relative standard deviation ranged from 4.1 % to 8.2 % and the fiber-to-fiber reproducibility for four prepared fibers was between 6.5 % and 10.8 %. The method was successfully applied to the analysis of CPs and OCPs in lake water and waste water samples. Recovery was tested with spiked lake water and waste water samples, with values ranging from 89.7 % to 101.2 % in case of waste water samples. (author)

  12. [Molecularly-imprinted solid phase extraction coupled with high performance liquid chromatography for the determination of ractopamine in feed samples].

    Science.gov (United States)

    Huang, Yi; Zhang, Qingjie; Liu, Min; Wang, Xufeng; Li, Jianqin; He, Limin

    2012-01-01

    Molecularly imprinted polymers (MIPs) with high selectivity to ractopamine (RAC) were prepared by using RAC as template, acrylamide (AM) as monomer, and ethylene glycol dimethacrylate (EGDMA) as cross-linker. The effects of four porogens (methanol, acetonitrile, acetone, and chloroform-methanol) with triethylamine (30:1, v/v) on the recognition capability of MIPs to RAC and the morphological characteristics of the polymers were investigated. Orthogonal test was used to optimize the preparation of MIPs, and the optimal compositions were as follows: 1.0 mmol RAC, 4.0 mmol AM, 20.0 mmol EGDMA, 6.0 mL acetonitrile-triethylamine (30:1, v/v), and 50.0 mg azobisisobutyronitrile. A high performance liquid chromatographic method based on molecularly-imprinted solid-phase extraction (MISPE) was developed for the determination of ractopamine in feed samples. The limit of detection (LOD, S/N = 3) of ractopamine was 0.1 mg/kg. The linear range was 0.50-100 mg/L (r = 0.999 4). Mean recoveries of RAC spiked in 3 kinds of feed samples at 1.0, 10 and 100 mg/kg were above 80% with the relative standard deviations of less than 10%. The clean-up efficiency of MISPE was ideal for feed samples. The method is more sensitive and reproduciable than the standard analytical method for the determination of RAC in feed matrices. PMID:22667092

  13. Determination of uranium and thorium isotopes by solid phase extraction and alpha spectrometry

    International Nuclear Information System (INIS)

    The aim of this work was to test the modified method suitable for the separation of isotopes of uranium and thorium samples of rocks, including gold ore and gold concentrate using of extraction chromatography method, after digestion of the sample, concentrating, separate the isotopes of uranium and thorium isotopes to prepare sources for the measurement of alpha spectra. Samples of rocks, gold ore and gold concentrate were digered in microwave decomposition in the environment of hydrogen peroxide and concentrated nitric acid. For the separation of uranium and thorium the vacuum box with cartridges DGA Resin and Resin(R) UTEVA (Triskem International, France) was used. Both sorbents allow separation of uranium from thorium. The results confirmed that the both sorbents give the same results within expanded uncertainty. The mass activity of monitored uranium and thorium radioisotopes was determined by alpha spectrometry method. The yields of separation were determined using uranium-232 as a tracer radionuclide; the activity of 232U was 0.1438 Bq. Alpha spectra were measured on the Alpha spectrometer EG and G ORTEC 576A with the software MAESTRO, MCA Emulator and Gamma Vision-32 for Windows, USA. Mass activities of radionuclides were converted to mass concentration of isotopes 238U, 234U, 232Th, 230Th and 228Th. The highest concentration of 238U was sampled in granodiorite (Tunnel S-XIV-2, southwards, mining of Cu ore, not working there since 1990), where m(238U) = (0.81 ± 0.09) mg kg-1 (DGA Resin) and m(238U) = (0.90 ± 0.09) mg kg-1 (UTEVA(R) Resin), as well as m(232Th) = (18.8 ± 1.7) mg kg-1 (DGA Resin) and m(232Th) = (17.8 ± 1.5) mg kg-1 (UTEVA(R) Resin). In other samples of rocks, gold ore and gold concentrates have specific masses of isotopes of uranium and thorium two-to ten-folds lower. It can be concluded that the rocks, gold ores and concentrates of gold from the 'Rozalia' mine contain lower concentrations of uranium several times against the mean abundance of uranium in the Earth's crust (?3 ppm), presence of thorium in these samples is comparable or lower to its abundance in the Earth's crust (?8 ppm). (author)

  14. Dispersive micro-solid phase extraction using magnetic nanoparticle modified multi-walled carbon nanotubes coupled with surfactant-enhanced spectrofluorimetry for sensitive determination of lomefloxacin and ofloxacin from biological samples.

    Science.gov (United States)

    Amoli-Diva, Mitra; Pourghazi, Kamyar; Hajjaran, Somayeh

    2016-03-01

    A dispersive micro-solid-phase extraction (D-?-SPE) procedure coupled with surfactant-enhanced spectrofluorimetric detection was developed for determination of ofloxacin and lomefloxacin from biological and environmental samples. The D-?-SPE procedure was performed using magnetic Fe3O4 nanoparticle grafted multi-walled carbon nanotube as an efficient adsorbent. The main factors affecting the signal enhancement (including surfactant concentration and pH) and extraction efficiency (including pH, extraction time, sample volume, amount of magnetic adsorbent, and desorption conditions) were investigated in detail. Under the optimized conditions, the calibration curves were linear (R(2)?0.9995) over the concentration range of 50-450ngmL(-1) with detection limits (LOD) of 12 and 15ngmL(-1) for ofloxacin and lomefloxacin respectively. The relative standard deviation (RSD %) of 1.9 and 2.1% (C=100ngmL(-1), n=5) and the enrichment factor of 192 and 188 were achieved for ofloxacin and lomefloxacin respectively. Finally, the method was successfully applied to the extraction and preconcentration of these drugs in biological (plasma and urine) samples. PMID:26706503

  15. Determination of pesticide residues in tomato using dispersive solid-phase extraction and gas chromatography/ion trap mass spectrometry

    Scientific Electronic Library Online (English)

    Graziela C. R. Moura, Andrade; Rosana M. O, Freguglia; Regina P. Z, Furlani; Nádia H, Torres; Valdemar L, Tornisielo.

    2011-09-01

    Full Text Available A cultura do tomate é frequentemente afetada por pragas, doenças e estresses abióticos, resultando em menor produtividade e perda de qualidade dos frutos. O uso intensivo de pesticidas em tomates sem utilização das boas práticas agrícolas tem causado grande preocupação quanto à provável contaminação [...] do produto final. O método QuEChERS foi utilizado para a determinação de seis pesticidas (buprofezina, carbofurano, ?-endosulfan, ?-endosulfan, sulfato de endosulfan e monocrotofós) em amostras de tomate coletadas em supermercados. O método envolveu a extração líquido-líquido com acetonitrila, adição de MgSO4 e NaCl seguida de extração em fase sólida dispersiva com PSA (amina primária secundária) e as análises foram realizadas com cromatografia gasosa/espectrometria de massa ion trap. O estudo de recuperação para os pesticidas variou de 71 a 111% e o desvio padrão relativo foi inferior a 15%. Não foram detectados resíduos de pesticidas (> LOD) nas trinta e três amostras de tomate analisadas. Abstract in english Tomato crop is frequently damaged by diseases, pests and abiotic stresses, resulting in lower yielding and loss of fruit quality. The intensive use of pesticides in tomatoes without observation of good agriculture practices and regulations has caused great concern with a probable final product conta [...] mination. The QuEChERS method of sample preparation was used for the determination of six pesticides (buprofezin, carbofuran, endosulfan-?, endosulfan-?, endosulfan sulfate and monocrotophos) in thirty three tomato samples collected from local market retailers. The method involved extraction with acetonitrile, liquid-liquid partition with addition of MgSO4 and NaCl followed by dispersive solid phase extraction using primary secondary amine sorbent and the analyses were carried out with a gas chromatography/mass spectrometry equipment by ion trap. Recovery studies for different pesticides ranged from 71 to 111% and the relative standard deviation (RSD) was below 15%. No pesticide residue was detected (> LOD) among the thirty three tomato samples analysed.

  16. Validation of a method using solid phase extraction and liquid chromatography for the determination of pesticide residues in groundwaters

    Scientific Electronic Library Online (English)

    Sergiane S., Caldas; Adriana, Demoliner; Ednei G., Primel.

    Full Text Available Neste trabalho, um método para determinação dos agrotóxicos carbofurano, clomazona, 2,4-D e tebuconazol em águas subterrâneas é descrito. O método utiliza a Extração em Fase Sólida (EFS) com cartuchos de C18 e quantificação por Cromatografia Líquida de Alta eficiência com Detector de Arranjo de Diod [...] os (CLAE-DAD). Após a otimização dos parâmetros de extração e separação dos compostos, o método foi validado avaliando-se curva analítica, linearidade, limites de detecção e quantificação, precisão e exatidão (recuperação). O método apresentou recuperações médias de 87,9% e 96,9%, para a repetibilidade e precisão intermediária, respectivamente, com RSD de 0,8 a 20,7% para todos os compostos. O método será empregado na determinação de agrotóxicos em águas subterrâneas com um limite de quantificação de 0,2 ?g L-1. Abstract in english A method is described for the determination of the pesticides carbofuran, clomazone, 2,4-D and tebuconazole in groundwaters. The method involves solid phase extraction (SPE) with C18 cartridges and quantification by high performance liquid chromatography with diode array detector (HPLC-DAD). After t [...] he optimization of the extraction and separation parameters, the method was validated by evaluating the analytical curve, linearity, limits of detection and quantification, precision and accuracy (recovery). The method presents an average recovery of 87.9% and 96.9%, in repeatability and intermediate precision conditions, respectively, with adequate precision (RSD from 0.8 to 20.7%), for all compounds. The method will be applied to determine pesticides in groundwater samples with limit of quantification of 0.2 ?g L-1.

  17. Determination of pyrrolizidine alkaloids in honey from selected sites by solid phase extraction and HPLC-MS.

    Science.gov (United States)

    Crews, C; Startin, J R; Clarke, P A

    1997-07-01

    A method was developed for the determination in honey of the Ragwort (Senecio jacobaea) derived pyrrolizidine alkaloids jacoline, jacozine, jacobine, seneciphylline and senecionine, combining solid-phase extraction with high performance liquid chromatography and atmospheric pressure chemical ionization mass spectrometric detection. The method allowed determination of individual alkaloids and offered a considerable improvement in terms of speed, sensitivity and specificity over previous approaches, but was not suitable for determination of jaconine, a minor alkaloid in Ragwort. Instrument calibrations were linear over the range 0.005 to 100 micrograms/ml, equivalent to approximately 0.001 to 2.0 mg/kg in honey with the extraction method used and allowing for observed recoveries. Detection limits in honey were 0.002 mg/kg. Recoveries for most of the alkaloids were between 57 and 70%. The alkaloids have been determined in a number of samples of honey selected after pollen identification and counting. The alkaloids were not detectable in samples containing two grains or less of Ragwort pollen per gram of honey. Samples collected in late July and August contained Ragwort pollen at 15-21 grains/g and total alkaloid concentrations of 0.011-0.056 mg/kg. Similar contributions to the total were made by jacozine, seneciophylline and senecionine, with jacobine making a larger and jacoline a smaller contribution. Two samples of honey containing Ragwort pollen at 24 and 16 grains/g had total alkaloid concentrations of 0.42 and 1.48 mg/kg respectively (not corrected for recovery). The alkaloid profile in these samples was dominated by seneciphylline and senecionine which together comprised 90-95% of the total. Alkaloids were not detected in retail honeys. PMID:9328525

  18. Analysis of Mars Analogue Soil Samples Using Solid-Phase Microextraction, Organic Solvent Extraction and Gas Chromatography/Mass Spectrometry

    Science.gov (United States)

    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.

  19. Clonazepam serum levels in epileptic patients determined simply and rapidly by high-performance liquid chromatography using a solid-phase extraction column.

    Directory of Open Access Journals (Sweden)

    Furuno,Katsushi

    1991-04-01

    Full Text Available We studied the use of high-performance liquid chromatography (HPLC, using a solid phase extraction column (Bond Elut cartridge column, for the simple, rapid and sensitive determination of serum clonazepam levels in epileptic patients. Extracted aliquots were analyzed by HPLC, using a reverse phase ODS column (mu-Bondapak C18. The analytical mean recovery of clonazepam added to the blank serum averaged 99.9%. The detection limit was as high as approximately 2 ng/ml in the serum. The reproducibilities were 2.3-8.6 CV % in the within-day assay and 6.5 CV % in the between-day assay, indicating that the analysis method was effective in the determination of clonazepam serum levels. Accordingly, we suggest that the present method, using a solid phase extraction column, may be useful for the routine monitoring of clonazepam serum levels in epileptic patients.

  20. Study of molecularly imprinted solid-phase extraction of gonyautoxins 2,3 in the cultured dinoflagellate Alexandrium tamarense by high-performance liquid chromatography with fluorescence detection

    International Nuclear Information System (INIS)

    A highly selective sample cleanup procedure combined with molecularly imprinted solid-phase extraction (MISPE) was developed for the isolation of gonyautoxins 2,3 (GTX2,3) from Alexandrium tamarense sample. The molecularly imprinted polymer microspheres (MIPMs) were prepared by suspension polymerization using caffeine as the dummy template molecule, methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the cross-linker and polyvinyl alcohol as the dispersive reagent. The polymer microspheres were used as a selective sorbent for the solid-phase extraction of gonyautoxins 2,3. An off-line MISPE method followed by high-performance liquid chromatography (HPLC) with fluorescence detection for the analysis of gonyautoxins 2,3 was established. Finally, the extract samples from Alexandrium tamarense were analyzed. The results showed the imprinted polymer microspheres exhibited high affinity and selectivity for gonyautoxins 2,3. The interference matrix in the extract were obviously cleaned by MISPE and the extraction efficiency of gonyautoxins 2,3 in the sample ranged from 81.74% to 85.86%. -- Graphical abstract: This is the SEM photograph of molecularly imprinted polymer microspheres (MIPMs). MIPMs were prepared by suspension polymerization and used as selective sorbents for the solid-phase extraction of gonyautoxins 2,3. An off-line MISPE method followed by high-performance liquid chromatography with fluorescence detection for the analysis of gonyautoxins 2,3 was established. The extract samples from Alexandrium tamarense were analyzed by molecularly imprinted solid-phase extraction. Highlights: •The molecularly imprinted polymer microspheres (MIPMs) for GTX2,3 were prepared. •The characteristics and regeneration property of MIPMs were studied. •An off-line method using MIPMs as solid-phase extraction (SPE) sorbents was developed. •GTX2,3 from Alexandrium tamarense extract was successfully isolated by MIPMs-SPE. -- MIPMs for GTX2,3 were prepared and applied as special SPE sorbents. The MISPE process was valid for the isolation and clean-up of GTX2,3 from A. tamarense extract

  1. Studies on liquid-liquid and solid phase extraction of rare earths from wet phosphoric acid solutions using organophosphorus based reagents

    International Nuclear Information System (INIS)

    Wet phosphoric acid (WPA) of fertilizer industry is a potential source for the recovery uranium and rare metals. This paper reports the liquid liquid extraction (LLE) and solid phase extraction (SPE) studies of rare earths from WPA solutions by organophosphorus extractants. We cover the potential resources of rare earths in the world and India, present status of rare metals recovery from WPA, research studies on rare metals in our lab. The results of our studies on heavy and light rare earths from WPA solutions reports the mechanism metal transfer, extraction behavior of associated metal, determination of separation factors (?) and their possible separations based on separation factors. (author)

  2. Pre-concentration and determination of trace uranium (VI) in environments using ion-imprinted chitosan resin via solid phase extraction

    Scientific Electronic Library Online (English)

    Yunhai, Liu; Xiaohong, Cao; Zhanggao, Le; Mingbiao, Luo; Wenyuan, Xu; Guolin, Huang.

    Full Text Available Foram preparadas resinas quitosana de ligação cruzada com impressão molecular de uranil e sem impressão, possuindo grupamentos quinolin-8-ol. Em todos os casos um efeito de impressão significativo foi observado na comparação do percentual de extração de urânio (VI). A resina com impressão molecular [...] foi usada para pré-concentração extrativa de urânio (VI) em fase sólida antes de determinação espectrofotométrica. Variáveis experimentais que influenciam a extração quantitativa de urânio (VI) foram otimizadas em método estático e em extração com coluna. A capacidade de retenção de urânio (VI) foi de 218 mg por g de resina, que é maior que a resina sem impressão molecular correspondente ou outra fase sólida adsorvente que possua grupamento quinolin-8-ol. O intervalo de pH ótimo encontrado foi 4,5-7,0. O urânio adsorvido foi fácil e quantitativamente eluido com HCl 1 mol L-1 (10 mL) sob uma vazão de 2 mL min-1. Estudos de interferentes mostraram uma alta tolerância para diversos íons e espécies eletrolíticas. O limite de detecção foi de 2 µL L-1 e o intervalo de concentração linear de 5-100 µg L-1. A exatidão do método foi testada com material padrão de referência de rocha de urânio. Além disso, o método foi aplicado para a determinação de urânio em amostras de solo contaminado e sedimento. Abstract in english The uranyl-ion-imprinted and non-imprinted cross-linked chitosan resins possessing quinoline-8-ol moiety have been prepared. In all the cases, a significant imprinting effect was noticed on comparing percent extraction of uranium (VI). The resulting ion-imprinted resin was used for solid phase extra [...] ctive preconcentration of uranium (VI) prior to its determination by spectrophotometry. Experimental variables that influence the quantitative extraction of uranium (VI) were optimized by both static and column methods. The retention capacity found for uranium (VI) was 218 mg g-1 of resin which is higher than the corresponding non-imprinted resins and other solid phase extraction sorbents possessing quinoline-8-ol moiety. The optimum pH range was 4.5-7.0. Uranium adsorbed was easily and quantitatively eluted with 1 mol L-1 HCl (10 mL) at a flow rate of 2 mL min-1. Interference studies showed a high tolerance of diverse ions and electrolyte species. The limit of detection was 2 µg L-1 and the dynamic linear range was 5-100 µg L-1. The accuracy of the developed method was tested with one uranium ore standard reference material. Furthermore, the proposed method was successfully applied for the determination of uranium in contaminated soil and sediment samples.

  3. A novel cation exchange polymer as a reversed-dispersive solid phase extraction sorbent for the rapid determination of rhodamine B residue in chili powder and chili oil.

    Science.gov (United States)

    Chen, Dawei; Zhao, Yunfeng; Miao, Hong; Wu, Yongning

    2014-12-29

    This paper presents a new analytical method for the determination of rhodamine B (RB) residue in chili powder and chili oil based on a novel reversed-dispersive solid phase extraction (r-dSPE) and ultra high performance liquid chromatography–high resolution mass spectrometry (UHPLC–HRMS). Chili powder and chili oil samples were first extracted with acetonitrile/water (1:1, v/v) and acetonitrile, respectively. Then, RB from the extract was adsorbed to the polymer cation exchange (PCX) sorbent with the characteristics of ion exchange and reversed-phase retention. Subsequently, the analyte in PCX sorbent was eluted with ammonium hydroxide/methanol (1:99, v/v) through a simple unit device equipped with 1 mL syringe and 0.22 ?m nylon syringe filter. All of the samples were analyzed by UHPLC–HRMS/MS on a Waters Acquity BEH C18 column with 0.1% formic acid and 4 mM ammonium formate in water/acetonitrile as the mobile phase with gradient elution. The matrix effect, recovery, and repeatability, within laboratory reproducibility, and the LODs and LOQs of the r-dSPE cleanup method were investigated. The method showed a good linearity (R2 > 0.999) in the ranges of 0.01–1 ?g/L and 1–100 ?g/L for the analyte. The LODs of RB for chili powder and chili oil samples were 0.5 ?g/kg. The average recoveries of RB from the samples spiked at four different concentrations (2, 20, 500 and 5000 ?g/kg) were in a range from 76.7 to 104.9%. Results showed that the proposed method was simple, fast, economical and effective for the determination of RB in chili powder and chili oil. Considering the excellent sorptive performance of PCX for RB, further work should be done to evaluate the usefulness of the PCX in r-dSPE for the clean-up and analyses of other trace-level alkaline contaminants. PMID:25498558

  4. Ligand-Less in situ Surfactant-Based Solid Phase Extraction for Preconcentration of Cobalt, Nickel and Zinc from Water Samples Prior to their FAAS Determination

    Scientific Electronic Library Online (English)

    Sayed Z., Mohammadi; Daryoush, Afzali; Zahra, Fallahi; Asieh, Mehrabi; Shima, Moslemi.

    2015-01-01

    Full Text Available Uma nova e simples extração de fase sólida (LL-ISSPE), baseada em surfactante, sem ligantes e in situ foi desenvolvida para a pré-concentração de cobalto, níquel e zinco em amostras de água. Neste método, um surfactante catiônico contendo um grupo alquila [...] (brometo de n-dodeciltrimetilamônio) é dissolvido na amostra aquosa e então um agente adequado de par iônico (ClO4?) é adicionado. Devido à interação entre o surfactante e o agente de par iônico, partículas sólidas são formadas e o precipitado do analito foi adsorvido na superfície do adsorvente. Após a centrifugação, o sedimento é dissolvido em 3,0 mL HNO3 em etanol e então aspirado diretamente na chama do espectrômetro de absorção atômica em chama. Variáveis que afetam a eficiência da extração, como pH, concentrações de surfactante e par iônico, quantidade de CO32?, tempo de extração, tempo e razão da centrífuga foram otimizados. Os limites de detecção para Co(II), Ni(II) e Zn(II) baseados em 3Sb/m foram 1,0, 1,5 e 0,3 ng mL?1, respectivamente. O método proposto foi aplicado com sucesso na determinação dos íons de cobalto, níquel e zinco em amostras de água reais. Abstract in english A new simple and rapid ligand-less in situ surfactant-based solid phase extraction (LL-ISSPE) was developed for preconcentration of cobalt, nickel and zinc in water samples. In this method, a cationic surfactant containing a proper alkyl group (n-dodecylt [...] rimethylammonium bromide) is dissolved in the aqueous sample and then a proper ion-pairing agent (ClO4?) is added. Due to the interaction between surfactant and ion-pairing agent, solid particles are formed and precipitate of the analytes was adsorbed on surface of sorbent. After centrifugation, the sediment is dissolved in 3.0 mL HNO3 in ethanol and then aspirated directly into the flame atomic absorption spectrometer. Variables affecting the extraction efficiencies such as pH, concentrations of surfactant and ion pair, CO32? amount, extraction time, time and rate of centrifuge were optimized. Detection limits for Co(II), Ni(II) and Zn(II) based on 3Sb/m were 1.0, 1.5 and 0.3 ng mL?1, respectively. The proposed method has been successfully applied for the determination of cobalt, nickel and zinc ions in real water samples.

  5. Determining estrogenic steroids in Taipei waters and removal in drinking water treatment using high-flow solid-phase extraction and liquid chromatography/tandem mass spectrometry

    International Nuclear Information System (INIS)

    River water and wastewater treatment plant (WWTP) effluents from metropolitan Taipei, Taiwan were tested for the presence of the pollutants estrone (E1), estriol (E3), 17?-estradiol (E2), and 17?-ethinylestradiol (EE2) using a new methodology that involves high-flow solid-phase extraction and liquid chromatography/tandem mass spectrometry. The method was also used to investigate the removal of the analytes by conventional drinking water treatment processes. Without adjusting the pH, we extracted 1-L samples with PolarPlus C18 Speedisks under a flow rate exceeding 100 mL/min, in which six samples could be done simultaneously using an extraction station. The adsorbent was washed with 40% methanol/60% water and then eluted by 50% methanol/50% dichloromethane. The eluate was concentrated until almost dry and was reconstituted by 20 ?L of methanol. Quantitation was done by LC-MS/MS-negative electrospray ionization in the selected reaction monitoring mode with isotope-dilution techniques. The mobile phase was 10 mM N-methylmorpholine aqueous solution/acetonitrile with gradient elution. Mean recoveries of spiked Milli-Q water were 65-79% and precisions were within 2-20% of the tested concentrations (5.0-200 ng/L). The method was validated with spiked upstream river water; precisions were most within 10% of the tested concentrations (10-100 ng/L) with most RSDs 1 and EE2 concentrations; disk overloading by water matrix may also impact analyte recoveries along with ion suppression. In the Taipei water study, the four steroid estrogens were detected in river samples (ca. 15 ng/L for E2 and EE2 and 35-45 ng/L for E1 and E3). Average levels of 19-26 ng/L for E1, E2, and EE2 were detected in most wastewater effluents, while only a single effluent sample contained E3. The higher level in the river was likely caused by the discharge of untreated human and farming waste into the water. In the drinking water treatment simulations, coagulation removed 20-50% of the estrogens. An increased dose of aluminum sulfate did not improve the performance. Despite the reactive phenolic moiety in the analytes, the steroids were decreased only 20-44% of the initial concentrations in pre- or post-chlorination. Rapid filtration, with crushed anthracite playing a major role, took out more than 84% of the estrogens. Except for E3, the whole procedure successfully removed most of the estrogens even if the initial concentration reached levels as high as 500 ng/L

  6. Magnetic in-tube solid phase microextraction.

    Science.gov (United States)

    Moliner-Martínez, Y; Prima-Garcia, Helena; Ribera, Antonio; Coronado, Eugenio; Campíns-Falcó, P

    2012-08-21

    We report a new in-tube solid phase microextraction approach named magnetic in-tube solid phase microextraction, magnetic-IT-SPME. Magnetic-IT-SPME has been developed, taking advantage of magnetic microfluidic principles with the aim to improve extraction efficiency of IT-SPME systems. First, a magnetic hybrid material formed by Fe(3)O(4) nanoparticles supported on SiO(2) was synthesized and immobilized in the surface of a bared fused silica capillary column to obtain a magnetic adsorbent extraction phase. The capillary column was placed inside a magnetic coil that allowed the application of a variable magnetic field. Acetylsalicylic acid, acetaminophen, atenolol, diclofenac, and ibuprofen were tested as target analytes. The application of a controlled magnetic field resulted in quantitative extraction efficiencies of the target analytes between 70 and 100%. These results demonstrated that magnetic forces solve the low extraction efficiency (10-30%) of IT-SPME systems, which is one of their main drawbacks. PMID:22861152

  7. Nanostructured conducting molecularly imprinted polymer for selective extraction of salicylate from urine and serum samples by electrochemically controlled solid-phase micro-extraction

    Energy Technology Data Exchange (ETDEWEB)

    Ameli, Akram [Department of Chemistry, Faculty of Science, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Alizadeh, Naader, E-mail: alizaden@modares.ac.ir [Department of Chemistry, Faculty of Science, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of)

    2011-11-30

    Highlights: Black-Right-Pointing-Pointer Overoxidized polypyrrole templated with salicylate has been utilized as conducting molecular imprinted polymer for EC-SPME. Black-Right-Pointing-Pointer This first study reported on conducting molecular imprinted polymer was used to EC-SPME of salicylate. Black-Right-Pointing-Pointer Proposed method, is particularly effective in sample clean-up and selective monitoring of salicylate in physiological samples. - Abstract: Overoxidized polypyrrole (OPPy) films templated with salicylate (SA) have been utilized as conducting molecular imprinted polymers (CMIPs) for potential-induced selective solid-phase micro-extraction processes. Various important fabrication factors for controlling the performance of the OPPy films have been investigated using fluorescence spectrometry. Several key parameters such as applied potential for uptake, release, pH of uptake and release solution were varied to achieve the optimum micro-extraction procedure. The film template with SA exhibited excellent selectivity over some interference. The calibration graphs were linear in the ranges of 5 Multiplication-Sign 10{sup -8} to 5 Multiplication-Sign 10{sup -4} and 1.2 Multiplication-Sign 10{sup -6} to 5 Multiplication-Sign 10{sup -4} mol mL{sup -1} and the detection limit was 4 Multiplication-Sign 10{sup -8} mol L{sup -1}. The OPPy film as the solid-phase micro-extraction absorbent has been applied for the selective clean-up and quantification of trace amounts of SA from physiological samples. The results of scanning electron microscopy (SEM) have confirmed the nano-structure morphologies of the films.

  8. Determination of phenolic acids and flavonoids in raw propolis by silica-supported ionic liquid-based matrix solid phase dispersion extraction high performance liquid chromatography-diode array detection.

    Science.gov (United States)

    Wang, Zhibing; Sun, Rui; Wang, Yuanpeng; Li, Na; Lei, Lei; Yang, Xiao; Yu, Aimin; Qiu, Fangping; Zhang, Hanqi

    2014-10-15

    The silica-supported ionic liquid (S-SIL) was prepared by impregnation and used as the dispersion adsorbent of matrix solid phase dispersion (MSPD) for the simultaneous extraction of eight phenolic acids and flavonoids, including caffeic acid, ferulic acid, morin, luteolin, quercetin, apigenin, chrysin, and kaempferide in raw propolis. High performance liquid chromatography with a Zorbax SB-C18 column (150mm×4.6mm, 3.5?m) was used for separation of the analytes. The mobile phase consisted of 0.2% phosphoric acid aqueous solution and acetonitrile and the flow rate of the mobile phase was 0.5mL/min. The experimental conditions for silica-supported ionic liquid-based matrix solid phase dispersion (S-SIL-based MSPD) were optimized. S-SIL containing 10% [C6MIM]Cl was used as dispersant, 20mL of n-hexane as washing solvent and 15mL of methanol as elution solvent. The ratio of S-SIL to sample was selected to be 4:1. The standard curves showed good linear relationship (r>0.9995). The limits of detection and quantification were in the range of 5.8-22.2ngmL(-1) and 19.2-74.0ngmL(-1), respectively. The relative standard deviations (RSDs) of intra-day and inter-day determination were lower than 8.80% and 11.19%, respectively. The recoveries were between 65.51% and 92.32% with RSDs lower than 8.95%. Compared with ultrasound-assisted extraction (UAE) and soxhlet extraction, the present method consumed less sample, organic solvent, and extraction time, although the extraction yields obtained by S-SIL-based MSPD are slightly lower than those obtained by UAE. PMID:25190186

  9. Measurement of Urinary Cadmium in Glazers Using Solid Phase Extraction Followed by Inductively Coupled Plasma Atomic Emission Spectroscopy

    Directory of Open Access Journals (Sweden)

    Seyed Jamaleddin Shahtaheri

    2012-07-01

    Full Text Available Glazers are exposed to a variety of heavy metals in the ceramic industry, causing adverse effect on the body systems. Cadmium is one of the major raw materials for production of colored glazes. To evaluate occupational exposure to cadmium, spot urine samples were collected from 49 tile and pottery glazers in Yazd City in 2010 at the beginning and end of the work shift (98 samples. Totally, 55 office workers were also evaluated as control group. Samples were prepared using solid phase extraction followed by Inductively Coupled Plasma Atomic Emission Spectroscopy. All the participants filled out a self administered questionnaire comprises questions about work shift, kind of job, use of mask, ventilation,work history, overtime work, age, weight, and height. The lung function tests were performed in a standing position according to the American Thoracic Society recommendation on both control andcadmium exposed individuals. Analysis of covariance (ANCOVA was used to evaluate the data. The mean values of cadmium levels before and after shift in study group was 3.88 and 10.85 ?g/gcreatinine,respectively. The mean values of cadmium levels at the end of the work shift in the glazers urine samples was almost 3.53 times higher than the control group and 2.17 times higher than the ACGIHbiological exposure indices (5 ?g/g creatinine. In addition the lung functions of glazers was significantly lower than the office workers (p<0.001. Exposure to cadmium in ceramic industry can lead to the reduction of respiratory capacity. Hygienic behaviors such as using protective mask and working in efficient ventilated workplaces can decrease the rate of occupational exposure to cadmium.

  10. Selective separation and determination of the synthetic colorants in beverages by magnetic solid-phase dispersion extraction based on a Fe3 O4 /reduced graphene oxide nanocomposite followed by high-performance liquid chromatography with diode array detection.

    Science.gov (United States)

    Wang, Xi; Chen, Ning; Han, Qing; Yang, Zaiyue; Wu, Jinhua; Xue, Cheng; Hong, Junli; Zhou, Xuemin; Jiang, Huijun

    2015-06-01

    A facile adsorbent, a nanocomposite of Fe3 O4 and reduced graphene oxide, was fabricated for the selective separation and enrichment of synthetic aromatic azo colorants by magnetic solid-phase dispersion extraction. The nanocomposite was synthesized in a one-step reduction reaction and characterized by atomic force microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction and Brunauer-Emmett-Teller analysis. The colorants in beverages were quickly adsorbed onto the surface of the nanocomposite with strong ?-? interactions between colorants and reduced graphene oxide, and separated with the assistance of an external magnetic field. Moreover, the four colorants in beverages were detected at different wavelengths by high performance liquid chromatography with diode array detection. A linear dependence of peak area was obtained over 0.05-10 ?g/mL with the limits of detection of 10.02, 11.90, 10.41, 15.91 ng/mL for tartrazine, allure red, amaranth, and new coccine, respectively (signal to noise = 3). The recoveries for the spiked colorants were in the range of 88.95-95.89% with the relative standard deviation less than 2.66%. The results indicated that the nanocomposite of Fe3 O4 and reduced graphene oxide could be used as an excellent selective adsorbent for aromatic compounds and has potential applications in sample pretreatment. PMID:25864558

  11. Direct sampling and analysis from solid-phase extraction cards using an automated liquid extraction surface analysis nanoelectrospray mass spectrometry system.

    Science.gov (United States)

    Walworth, Matthew J; ElNaggar, Mariam S; Stankovich, Joseph J; Witkowski, Chuck; Norris, Jeremy L; Van Berkel, Gary J

    2011-09-15

    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 a liquid extraction surface analysis (LESA) mode on a commercially available chip-based infusion nanoelectrospray ionization (nanoESI) system. In the present paper, the LESA mode was applied to the analysis of 96-well format custom-made solid-phase extraction (SPE) cards, with each well consisting of either a 1 or a 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 commercial nanoESI system coupled to a hybrid triple quadrupole/linear ion trap mass spectrometer or a linear ion trap mass spectrometer. The 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 10× increase in signal and cleanup of micromolar angiotensin II from a concentrated salt solution was demonstrated. In addition, a multicomponent herbicide mixture at ppb concentration levels was analyzed using MS(3) spectra for compound identification in the presence of isobaric interferences. PMID:21793068

  12. Isocratic Solid Phase Extraction-Liquid Chromatography (SPE-LC) Interfaced to High-Performance Tandem Mass Spectrometry for Rapid Protein Identification

    DEFF Research Database (Denmark)

    Hørning, Ole B; Kjeldsen, Frank; Theodorsen, Søren; Vorm, Ole; Jensen, Ole Nørregaard

    2008-01-01

    Reversed-phase liquid chromatography interfaced to electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) allows analysis of very complex peptide mixtures at great sensitivity, but it can be very time-consuming, typically using 60 min, or more, per sample analysis. We recently introduced the isocratic solid phase extraction-liquid chromatography (SPE-LC) technology for rapid separation ( approximately 8 min) of simple peptide samples. We now extend these studies to demonstrate the poten...

  13. Application of Solid Phase Extraction on Multiwalled Carbon Nanotubes of Some Heavy Metal Ions to Analysis of Skin Whitening Cosmetics Using ICP-AES

    OpenAIRE

    Kamal Omer; Zeid A. Alothman; Mohammad Abulhassan Abdalla; ALqadami, Ayoub A.

    2013-01-01

    A novel and highly sensitive method for the determination of some heavy metals in skin whitening cosmetics creams using multiwalled carbon nanotubes MWCNTs as solid phase extraction sorbent for the preconcentration of these heavy metals prior to their determination by inductively coupled plasma atomic emission spectrometry is described. Different practical parameters have been thoroughly investigated and the optimum experimental conditions were employed. The developed method was then applied ...

  14. Direct Zinc Determination in Brazilian Sugar Cane Spirit by Solid-Phase Extraction Using Moringa oleifera Husks in a Flow System with Detection by FAAS

    OpenAIRE

    Alves, Vanessa N.; Borges, Simone S. O.; Nivia M. M. Coelho

    2011-01-01

    This paper reports a method for the determination of zinc in Brazilian sugar cane spirit, (cachaça in Portuguese), using solid-phase extraction with a flow injection analysis system and detection by FAAS. The sorbent material used was activated carbon obtained from Moringa oleifera husks. Flow and chemical variables of the proposed system were optimized through multivariate designs. The factors selected were sorbent mass, sample pH, sample flow rate, and eluent concentration. The optimum ext...

  15. Dispersive solid phase extraction combined with ion-pair ultra high-performance liquid chromatography tandem mass spectrometry for quantification of nucleotides in Lactococcus lactis

    DEFF Research Database (Denmark)

    Magdenoska, Olivera; Martinussen, Jan; Thykær, Jette; Nielsen, Kristian Fog

    2013-01-01

    Analysis of intracellular metabolites in bacteria is of utmost importance for systems biology and at the same time analytically challenging due to the large difference in concentrations, multiple negative charges, and high polarity of these compounds. To challenge this, a method based on dispersive solid phase extraction with charcoal and subsequent analysis with ion-pair liquid chromatography coupled with electrospray ionization tandem mass spectrometry was established for quantification of int...

  16. Purification and determination of plant hormones auxin and abscisic acid using solid phase extraction and two-dimensional high performance liquid chromatography.

    Czech Academy of Sciences Publication Activity Database

    Dobrev, Petre; Havlí?ek, Libor; Vágner, Martin; Malbeck, Ji?í; Kamínek, Miroslav

    2005-01-01

    Ro?. 1075, 1-2 (2005), s. 159-166. ISSN 0021-9673 R&D Projects: GA ?R GP522/02/D058; GA ?R GA206/02/0967; GA MŠk LN00A081; GA ?R GA522/04/0549; GA MZe QF4176 Institutional research plan: CEZ:AV0Z50380511 Keywords : Auxin * Abscisic acid * Solid phase extraction Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.096, year: 2005

  17. 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

    OpenAIRE

    Zambrzycka, El?bieta; Godlewska-?y?kiewicz, 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 r...

  18. LC-UV-solid-phase extraction-NMR-MS combined with a cryogenic flow probe and its application to the identification of compounds present in Greek oregano

    OpenAIRE

    Exarchou, V.; Godejohann, M.; Beek, T.A., van; Gerothanassis, I.P.; Vervoort, J.J.M.

    2003-01-01

    Structure elucidation of natural products usually relies on a combination of NMR spectroscopy with mass spectrometry whereby NMR trails MS in terms of the minimum sample amount required. In the present study, the usefulness of on-line solid-phase extraction (SPE) in LC-NMR for peak storage after the LC separation prior to NMR analysis is demonstrated. The SPE unit allows the use of normal protonated solvents for the LC separation and fully deuterated solvents for flushing the trapped compound...

  19. Methodology for the determination of residues of organophosphorous pesticides in milk of domestic consumption by means of gas chromatography and extraction in solid phase

    International Nuclear Information System (INIS)

    A new method oriented to the detection and quantification of 15 organophosphate pesticide in raw milk samples for national consumption has been developed by using a gas chromatograph equipped with polydimethylsiloxane capillary column and a nitrogen-phosphorus detector (NPD), in combination with the extraction technique in solid phase (SPE) for the sample cleaning process and pesticide extraction. Recovery percentages obtained were close to 100% and the detection limits obtained were lower than 20 ?g/L for 13 of the organophosphates analyzed. Overall, the method showed important improvement as compared to conventional liquid/liquid extraction methodologies. (Author)

  20. Comparison of an acetonitrile extraction/partitioning and “dispersive solid-phase extraction” method with classical multi-residue methods for the extraction of herbicide residues in barley samples

    OpenAIRE

    Diez, C.; Traag, W.A.; Zommer, P.; Marinero, P.; Atienza, J.

    2006-01-01

    An acetonitrile/partitioning extraction and "dispersive solid-phase extraction (SPE)" method that provides high quality results with a minimum number of steps and a low solvent and glassware consumption was published in 2003. This method, suitable for the analysis of multiple classes of pesticide residues in foods, has been given an acronymic name, QuEChERS, that reflects its major advantages (quick, easy, cheap, effective, rugged, safe). In this work, QuEChERS method, which was originally cr...

  1. Atomic absorption spectrometric determination of some metal ions after preconcentration by solid phase extraction using amberlite XAD 16 resin loaded with thenoyltrifluoroacetone

    International Nuclear Information System (INIS)

    Complete text of publication follows. The direct determination of extremely low concentrations of trace elements by modern atomic spectroscopic methods, such as atomic absorption spectrometry and inductively coupled plasma atomic emission spectrometry is often difficult because of insufficient sensitivity and selectivity of the methods used. For this reason, the preliminary separation and preconcentration of trace elements from the matrix are often required. Solid phase extraction shows several major advantages such as simplicity, rapidity and high enrichment factor, the ability of combination with different detection techniques in the form of on-line or off-line mode and finally cost saving (Tokalioglu et al., Microchim Acta 164 (2009) 471-477.). A new solid phase extraction method for the separation and preconcentration of Cu(II), Pb(II), Ni(II), Co(II), Mn(II) and Fe(III) ions was developed. As solid phase material, Amberlite XAD-16 resin loaded with thenoyltrifluoroacetone (TTA) was used. For this purpose, 0.5 g of the resin was saturated with 10 mL of 0.5% (w/v) TTA solution. After preconcentrating, the metals retained on the resin were eluted with 10 mL of 2 mol L-1 HCl and then determined by flame atomic absorption spectrometry. The effect of some parameters for the preconcentration of the metal ions was investigated. The optimum pH was found as 6. Eluent for quantitative elution was 10 mL of 2 mol L-1 HCl.

  2. Tropical peat as a versatile material for solid-phase extraction of pesticides from medicinal plant Cordia salicifolia

    Scientific Electronic Library Online (English)

    Pedro H. V. de, Carvalho; Amanda M. D. de, Jesus; Vanessa M., Prata; Débora S. S., Bezerra; Luciane P. C., Romão; Sandro, Navickiene.

    Full Text Available A turfa natural foi testada na extração em fase sólida de acefato, clorprofam, pirimicarbe, bifentrina, tetradifona e fosalona da planta medicinal Cordia salicifolia, utilizando cromatografia a gás acoplada a espectrometria de massas no modo de monitoramento de íons selecionados. Considerando que a [...] legislação brasileira não estabelece limites máximos de resíduos para plantas medicinais, a recuperação foi avaliada em dois níveis de concentração (0,5 e 1,0 mg kg-1), resultando em valores de recuperação entre 64% e 118%, com coeficientes de variação entre 5,6% e 26,4% para a turfa. Os limites de detecção variaram entre 0,10 e 0,15 mg kg-1, enquanto que os limites de quantificação, entre 0,15 e 0,25 mg kg-1 para os pesticidas estudados. O método desenvolvido foi linear no intervalo de 0,1 a 5,0 ?g g-1, com coeficientes de correlação entre 0,9975 e 0,9986. A comparação entre a turfa natural e o sorbente convencional (alumina neutra) apresentou desempenho similar da turfa na recuperação dos seis pesticidas. Abstract in english Natural peat was tested for solid-phase extraction of acephate, chlorpropham, pirimicarb, bifenthrin, tetradifon and phosalone from the medicinal plant Cordia salicifolia, using gas chromatography-mass spectrometry with selected ion monitoring (GC/MS, SIM). Considering that there are no Brazilian re [...] gulations concerning maximum permissible pesticide residue concentrations in medicinal herbs, recovery experiments were carried out (three replicates) at two arbitrary fortification levels (0.5 and 1.0 mg kg-1), resulting in recoveries ranging from 64% to 118% and relative standard deviations between 5.6% and 26.4% for peat sorbent. Detection and quantification limits for herb ranged from 0.10 to 0.15 mg kg-1 and from 0.15 to 0.25 mg kg-1, respectively, for the different pesticides studied. The developed method was linear over the range assayed, 0.1-5.0 ?g g-1, with correlation coefficients ranging from 0.9975 to 0.9986 for all pesticides. Comparison between natural peat and conventional sorbent (neutral alumina) showed similar performance of peat for the six pesticides tested.

  3. Development of colorimetric solid Phase Extraction (C-SPE) for in-flight Monitoring of spacecraft Water Supplies

    Energy Technology Data Exchange (ETDEWEB)

    Daniel Bryan Gazda

    2004-12-19

    Although having recently been extremely successful gathering data on the surface of Mars, robotic missions are not an effective substitute for the insight and knowledge about our solar system that can be gained though first-hand exploration. Earlier this year, President Bush presented a ''new course'' for the U.S. space program that shifts NASA's focus to the development of new manned space vehicles to the return of humans to the moon. Re-establishing the human presence on the moon will eventually lead to humans permanently living and working in space and also serve as a possible launch point for missions into deeper space. There are several obstacles to the realization of these goals, most notably the lack of life support and environmental regeneration and monitoring hardware capable of functioning on long duration spaceflight. In the case of the latter, past experience on the International Space Station (ISS), Mir, and the Space Shuttle has strongly underscored the need to develop broad spectrum in-flight chemical sensors that: (1) meet current environmental monitoring requirements on ISS as well as projected requirements for future missions, and (2) enable the in-situ acquisition and analysis of analytical data in order to further define on-orbit monitoring requirements. Additionally, systems must be designed to account for factors unique to on-orbit deployment such as crew time availability, payload restrictions, material consumption, and effective operation in microgravity. This dissertation focuses on the development, ground testing, and microgravity flight demonstration of Colorimetric Solid Phase Extraction (C-SPE) as a candidate technology to meet the near- and long-term water quality monitoring needs of NASA. The introduction will elaborate further on the operational and design requirements for on-orbit water quality monitoring systems by discussing some of the characteristics of an ''ideal'' system. A description of C-SPE and how the individual components of the platform are combined to satisfy many of these requirements is then presented, along with a literature review on the applications of C-SPE and similar sorption-spectrophotometric techniques. Finally, a brief overview of diffuse reflection spectroscopy and the Kubelka-Munk function, which are used to quantify analytes via C-SPE, is presented.

  4. Analysis of dextromethorphan and dextrorphan in decomposed skeletal tissues by microwave assisted extraction, microplate solid-phase extraction and gas chromatography- mass spectrometry (MAE-MPSPE-GCMS).

    Science.gov (United States)

    Fraser, Candice D; Cornthwaite, Heather M; Watterson, James H

    2015-08-01

    Analysis of decomposed skeletal tissues for dextromethorphan (DXM) and dextrorphan (DXT) using microwave assisted extraction (MAE), microplate solid-phase extraction (MPSPE) and gas chromatography-mass spectrometry (GC-MS) is described. Rats (n?=?3) received 100?mg/kg DXM (i.p.) and were euthanized by CO2 asphyxiation roughly 20?min post-dose. Remains decomposed to skeleton outdoors and vertebral bones were recovered, cleaned, and pulverized. Pulverized bone underwent MAE using methanol as an extraction solvent in a closed microwave system, followed by MPSPE and GC-MS. Analyte stability under MAE conditions was assessed and found to be stable for at least 60?min irradiation time. The majority (>90%) of each analyte was recovered after 15?min. The MPSPE-GCMS method was fit to a quadratic response (R(2) ?>?0.99), over the concentration range 10-10 000?ng?mL(-1) , with coefficients of variation <20% in triplicate analysis. The MPSPE-GCMS method displayed a limit of detection of 10?ng?mL(-1) for both analytes. Following MAE for 60?min (80?°C, 1200?W), MPSPE-GCMS analysis of vertebral bone of DXM-exposed rats detected both analytes in all samples (DXM: 0.9-1.5?µg?g(-1) ; DXT: 0.5-1.8?µg?g(-1) ). PMID:25487525

  5. Comparison of different types of coatings in headspace solid phase micro extraction for the analysis of pesticide residues in vegetables and fruits

    International Nuclear Information System (INIS)

    Despite the continuing development of solid-phase micro extraction (SPME) fiber coatings, their selection presents some difficulties for analytes in choosing the appropriate fiber for a particular application. There are many types of SPME coatings available commercially. The most widely used for determination of pesticide residues in vegetable and fruits are polydimethylsiloxane (PDMS) and polyacrylate (PA). A headspace solid phase micro extraction (HS-SPME) procedure using these two commercialized fibers (PDMS and PA) is presented for the determination of selected groups of organo chlorine and organophosphorus pesticides. The extraction performances of these compounds were compared using these two fibers. The optimal experimental procedures for the adsorption and desorption of pesticides were determined. An explanation for the extraction differences is suggested based on the different thickness, polarity of the polymeric film of fibers and the different extracting matrices. In addition, the higher detector response of the pesticides after addition of aliquots of water and an organic solvent to the vegetable and fruit samples are also discussed. The SPME fibers were reusable until a maximum of 120 extractions. Finally, the optimized procedures were applied successfully for the determination of these compounds in vegetable and fruits samples. Mean recoveries for all pesticides were between 75.0-97 % with RSD below 7 %. (author)

  6. Aplicação de SPME (Solid Phase Micro-Extraction na análise de águas potáveis de três localidades do estado de São Paulo

    Directory of Open Access Journals (Sweden)

    Valente Antonio Luiz Pires

    1998-01-01

    Full Text Available The technique of solid phase microextraction (SPME was used for the extraction of halogenated contaminants of water samples from three cities of the State of São Paulo and the extracts were submitted to gas chromatographic analysis with electron capture detection (GC-ECD. In the samples of water collected at the city of São Paulo the detected level of trihalomethanes (THM expressed as the sum of chloroform, dibromochloromethane and dichlorobromomethane, were higher than the permissible limit established by the Brazilian regulation. In the samples collected at the two other cities the level of any of the three THM remained below the sensitivity of the ECD.

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

    Science.gov (United States)

    Sánchez-González, Juan; Jesús Tabernero, María; María Bermejo, Ana; 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. PMID:26592657

  8. Magnetic solid-phase extraction based on mesoporous silica-coated magnetic nanoparticles for analysis of oral antidiabetic drugs in human plasma

    International Nuclear Information System (INIS)

    In the present work, magnetic nanoparticles embedded into mesoporous silica were prepared in two steps: first, magnetite was synthesized by oxidation–precipitation method, and next, the magnetic nanoparticles were coated with mesoporous silica by using nonionic block copolymer surfactants as structure-directing agents. The mesoporous SiO2-coated Fe3O4 samples were functionalized using octadecyltrimethoxysilane as silanizing agent. The pure and functionalized silica nanoparticles were physicochemically and morphologically characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N2 adsorption, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The resultant magnetic silica nanoparticles were applied as sorbents for magnetic solid-phase extraction (MSPE) of oral antidiabetic drugs in human plasma. Our results revealed that the magnetite nanoparticles were completely coated by well-ordered mesoporous silica with free pores and stable pore walls, and that the structural and magnetic properties of the Fe3O4 nanoparticles were preserved in the applied synthesis route. Indeed, the sorbent material was capable of extracting the antidiabetic drugs from human plasma, being useful for the sample preparation in biological matrices. - Highlights: • SBA-15/Fe3O4 was synthesized and functionalized with octadecyltrimethoxysilane. • Magnetite nanoparticles were completely coated by well-ordered mesoporous silica. • The samples were used as sorbent for magnetic solid-phase extraction (MSPE). • The sorbent material was capable of extracting drugs from human plasma. • The extraction ability makes the material a candidate to be employed as MSPE

  9. Predicting the performance of molecularly imprinted polymers: Selective extraction of caffeine by molecularly imprinted solid phase extraction

    International Nuclear Information System (INIS)

    A rational design approach was taken to the planning and synthesis of a molecularly imprinted polymer capable of extracting caffeine (the template molecule) from a standard solution of caffeine and further from a food sample containing caffeine. Data from NMR titration experiments in conjunction with a molecular modelling approach was used in predicting the relative ratios of template to functional monomer and furthermore determined both the choice of solvent (porogen) and the amount used for the study. In addition the molecular modelling program yielded information regarding the thermodynamic stability of the pre-polymerisation complex. Post-polymerisation analysis of the polymer itself by analysis of the pore size distribution by BET yielded significant information regarding the nature of the size and distribution of the pores within the polymer matrix. Here is proposed a stepwise procedure for the development and testing of a molecularly imprinted polymer using a well-studied compound-caffeine as a model system. It is shown that both the physical characteristics of a molecularly imprinted polymer (MIP) and the analysis of the pre-polymerisation complex can yield vital information, which can predict how well a given MIP will perform

  10. Use of Solid Phase Extraction with Hydrophilic-Lipophilic Balance (HLB) Cartridge as the Appropriate Option for Metribuzin Extraction from Contaminated Soils

    Scientific Electronic Library Online (English)

    Mohammad R., Rigi; Mohsen, Farahbakhsh; Karamatollah, Rezaei.

    2015-01-01

    Full Text Available Visando analizar resíduos de metribuzin em amostras de solo, precisamos usar métodos de extração especiais e adequados com alta eficiência. Cinco métodos de extração simples e rápidos (extração em fase sólida (SPE) com balanço hidrofílico-lipofílico (HLB) [...] , SPE com nanotubos de carbono de paredes múltiplas (MWCNTs), ultrassom, método quick, easy, cheap, effective, rugged and safe (QuECheRS) e extração líquido-sólido) acoplado a cromatografia gasosa foram usados na análise de resíduos do herbicida metribuzin em solos. Valores médios de recuperação do analito foram > 80%. Os extratos foram analizados por um sistema de cromatografia gasosa (GC) equipado com um detector de captura de elétrons (ECD). A ordem de valores médios de recuperação de metribuzin pelos cinco métodos de extração é: SPE com HLB > SPE com MWCNTs > ultrassom > QuECheRS > extração líquido-sólido. A recuperação média do analito depende do tipo de solo. Os resultados deste estudo mostram que o método de extração SPE com HLB é a melhor opção para extrair metribuzin de solos selecionados. Abstract in english With a view to analyze metribuzin residues in soil samples, we need to use special and suitable extraction methods with high efficiency. Five simple and rapid extraction methods (solid phase extraction (SPE) with hydrophilic-lipophilic balance (HLB), SPE [...] with multi-walled carbon nanotubes (MWCNTs), ultrasonic, quick, easy, cheap, effective, rugged and safe (QuECheRS) method, and liquid-solid extraction) coupled to gas chromatography were used for the analysis of metribuzin herbicide residues in soils. Mean recovery values of analyte were > 80%. Extracts were analyzed by a gas chromatographic (GC) system equipped with an electron capture detector (ECD). The order of mean recovery values of metribuzin for the five extraction methods is: SPE with HLB > SPE with MWCNTs > ultrasonic > QuECheRS > liquid-solid extraction. Mean recovery of analyte depends on the type of soil. The results of this study show that SPE with HLB extraction method is the best option for extracting metribuzin in selected soils.

  11. Trace and ultratrace determination of heavy metal ions by energy-dispersive X-ray fluorescence spectrometry using graphene as solid sorbent in dispersive micro solid-phase extraction

    International Nuclear Information System (INIS)

    In this paper, the adsorptive properties of graphene nanosheets were used for simultaneous preconcentration of cobalt, nickel, copper and lead ions from water samples. The developed methodology is based on dispersive micro-solid phase extraction (DMSPE) which is miniaturized and a simplified version of classical solid phase extraction technique. In proposed procedure only 200 ?L of suspension containing graphene (0.2 mg), ammonium pyrrolidine dithiocarbamate (APDC) (0.8 mg) and Triton-X-100 (0.1 mg) is rapidly injected to 50 mL of water sample. Then, graphene nanosheets with adsorbed metal-APDC chelates are collected on membrane filter and measured using energy-dispersive X-ray fluorescence (EDXRF) spectrometry. The various parameters including pH, amount of APDC, sample volume, amount of Triton-X-100 and sorption time were optimized in order to obtain the best recoveries. The experiment shows that Co, Ni, Cu and Pb can be simultaneously preconcentrated at pH of 5 with high recoveries (97%, 96%, 99% and 96% for Co, Ni, Cu and Pb, respectively) and very good precision (RSDs within 2.6–3.4%). Due to the excellent enrichment factors ranging from 400 to 2500 the proposed DMSPE–EDXRF procedure offers low detection limits. For optimized measurement conditions (voltage and current of X-ray tube, primary beam filter) the detection limits are even 0.08, 0.07, 0.08 and 0.20 ng mL?1 for Co, Ni, Cu and Pb, respectively. - Highlights: • Excellent detection limits using EDXRF • A new preconcentration procedure combining DMSPE and EDXRF measurement • Graphene as a promising and efficient solid sorbent in DMSPE • Simple, fast, inexpensive and environmental friendly method

  12. Solid-phase extraction based on a molecularly imprinted polymer for the selective determination of four benzophenones in tap and river water.

    Science.gov (United States)

    Sun, Hao; Li, Yun; Huang, Chaonan; Peng, Junyu; Yang, Jiajia; Sun, Xiaoli; Zang, Shuliang; Chen, Jiping; Zhang, Xiangdong

    2015-10-01

    This work reports the preparation of molecularly imprinted polymer particles for the selective extraction and determination of four benzophenones from aqueous media. The polymer was prepared by using 4-vinylpridine as functional monomer, ethylene glycol dimethacrylate as cross-linker, acetonitrile as porogenic solvent and 2,2',4,4'-tetrehydroxybenzophenone as template. Good specific adsorption capacity (Qmax = 27.90 ?mol/g) for 2,2',4,4'-tetrehydroxybenzophenone was obtained in the sorption experiment and good class selectivity for 2,2',4,4'-tetrehydroxybenzophenone, 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dehydroxy-4,4'-dimethoxybenzophenone was demonstrated by the chromatographic evaluation experiment. Factors affecting the extraction efficiency of the molecularly imprinted solid-phase extraction procedure were investigated systematically. An accurate and sensitive analytical method based on the molecularly imprinted solid-phase extraction coupled with high-performance liquid chromatography and diode array detection has been successfully developed for the simultaneous determination of four benzophenones from tap water and river water with method detection limits of 0.25-0.72 ng/mL. The recoveries of benzophenones for water samples at two spiking levels (500 and 5000 ng/mL for each benzophenone) were in the range of 86.9-103.3% with relative standard deviations (n = 3) below 9.2%. PMID:26179642

  13. A Taiji-principle-designed magnetic porous C-doped graphitic carbon nitride for environment-friendly solid phase extraction of pollutants from water samples.

    Science.gov (United States)

    Wang, Man; Yuan, Hao; Deng, Wenjing; Bi, Wentao; Yang, Xiaodi

    2015-09-18

    A new magnetic porous carbon-doped graphitic carbon nitride nanocomposite and experimental strategies were environment-friendly designed for solid phase extraction of brominated flame retardants from water sample. The easily synthesized and low cost nanocomposite was characterized using techniques, including Fourier transform infrared spectroscopy, X-ray diffraction spectrometry, elemental analysis, and transmission electron microscopy. The large surface area and enhanced interactions of this nanocomposite with its adsorption behavior in Taiji principle (a balance of hydrophilicity and hydrophobicity) in aqueous phase benefit the extraction. Magnetic solid phase extraction has advantages such as low solvent consumption and reusability of the sorbent, and was therefore employed in this study. In addition, a quicker and less laborious statistical method, known as response surface methodology, was used to investigate and optimize some crucial factors that affected the adsorption. The combined use of this new nanocomposite and experimental strategy showed excellent precision (2.7-5.2%) and sensitivity (limits of detection (S/N=3): 0.1-0.2 ?g L(-1)). This method was successfully applied to the analysis of real water samples giving good spiked recoveries over the range of 92.4-99.8%. This research provides an environment-friendly strategy to prepare suitable sorbents for extraction or adsorption of various compounds within different matrices. PMID:26278354

  14. Analysis of trace microcystins in vegetables using solid-phase extraction followed by high performance liquid chromatography triple-quadrupole mass spectrometry.

    Science.gov (United States)

    Li, Yan-Wen; Zhan, Xiao-Jing; Xiang, Lei; Deng, Zhe-Shen; Huang, Bin-Hui; Wen, Hong-Fei; Sun, Teng-Fei; Cai, Quan-Ying; Li, Hui; Mo, Ce-Hui

    2014-12-10

    A selective and sensitive method for the simultaneous detection of three common and hazardous microcystins (microcystins-LR, -RR, and -YR) in various vegetables was established using solid-phase extraction followed by high performance liquid chromatography coupled with mass spectrometry. The methanol-water proportion ratio of the extraction solvent and its acidity, as well as the efficiencies of solid-phase extraction, were evaluated to optimize a pretreatment procedure for extracting the microcystins from 10 vegetable matrices. The limits of detection and quantitation were below 7.5 ?g/kg (dw) and 25 ?g/kg (dw), respectively, in different vegetable matrices. The recoveries of the microcystins in the 10 vegetable matrices ranged from 61.3 to 117.3%, with RSDs of 0.2-18.3%. The established method was used to analyze 28 field vegetable samples collected from the sides of Lake Dianchi, and microcystin-RR was found in almost all samples at concentrations of 36.4-2352.2 ?g/kg (dw). PMID:25393522

  15. Determination of vanadium(V) in the particulate matter of emissions and working areas by sequential dissolution and solid-phase extraction

    International Nuclear Information System (INIS)

    A method based on selective sequential dissolutions is proposed to determine total vanadium(V) in particulate matter of emissions and working areas at concentrations 1,000 times lower than the threshold limit of 0.05 mg m-3. Separation and preconcentration of vanadium(V) has been achieved by solid-phase extraction on Chelex 100 resin. Possible influence of the matrix has been investigated for two standard reference materials (SRMs), NIST SRM 1648 and BCR-038, before and after spiking, with vanadium(V) recovery in the range 97-103%. (orig.)

  16. The application of micro-column solid phase extraction techniques for the determination of rare earth elements in actinide containing matrices

    International Nuclear Information System (INIS)

    The design and characterization of an argon segmented-solid phase extraction system is described. A 200 ul volume micro-column has been constructed for the preconcentration of rare earth elements (REEs) from salt matrices containing uranium. An inductively coupled plasma atomic emission spectrometer has been utilized for simultaneous detection of Sr, Y and the REEs (namely Ce, Eu, La, Nd, Pr, Sm) at levels ranging from 5- to 2000 ppm in LiCl/KCl samples containing U. Preconcentration factors of 100 fold have been demonstrated. The precision, linear dynamic range and column performance of the system will be presented. (author). 5 refs., 5 figs., 3 tabs

  17. Determination of sub-ppb epichlorohydrin levels in water by on-line solid-phase extraction liquid chromatography/tandem mass spectrometry

    OpenAIRE

    Ripollés Vidal, Cristina; Marín Ramos, José Manuel; López Benet, Francisco José; Sancho Llopis, Juan Vicente; Hernández Hernández, Félix

    2009-01-01

    A new sensitive and selective method based on on-line solid-phase extraction (SPE) coupled to liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) using a triple quadrupole mass spectrometer has been developed for the determination of epichlorohydrin (ECH) in different types of water samples. ECH is not easily determined directly by ESI-MS as it is not readily ionized, and it has a low molecular mass and high polarity. Thus, prior derivatization of ECH was nec...

  18. [The use of a method of solid-phase extraction for sample preparation in the identification of unknown substances by IR spectroscopy].

    Science.gov (United States)

    Beliaev, A V; Sorokin, V I; Orlova, O S; Kimstach, T B

    1997-01-01

    Identification of synthetic narcotics is difficult because they do not possess any apparent individual signs and the specimens are contaminated with various fillers and additives, which rules out investigations by infrared spectroscopy, widely used in expert practice. Use of solid-phase extraction during preparation of samples helps prepare highly purified samples which can be further identified by IR spectroscopy. The authors present the protocol of identification of unknown substances and recognition of narcotics and describe methods for identification of some confiscated narcotics (methadone, MDA, phencyclidine, methaqualone, codeine, ethylmorphine, cocaine, etc.). PMID:9304249

  19. Integrated Solid-Phase Extraction-Capillary Liquid Chromatography (speLC) Interfaced to ESI-MS/MS for Fast Characterization and Quantification of Protein and Proteomes

    DEFF Research Database (Denmark)

    Falkenby, Lasse Gaarde; Such-Sanmartín, Gerard

    2014-01-01

    The high peptide sequencing speed provided by modern hybrid tandem mass spectrometers enables the utilization of fast liquid chromatographic (LC) separation techniques. We present a robust solid-phase extraction/capillary LC system (speLC) for 5-10 min separation of semicomplex peptide mixtures prior to ESI-MS/MS for peptide sequencing. This speLC-MS/MS system eliminates sample-to-sample carry-over by using disposable micropipette solid-phase extraction tips (StageTips) for peptide sample loading, concentration, and desalting. Automated analysis of 192 replicates of E. coli peptide mixtures in 30 h demonstrated the throughput, stability, and reproducibility of the system. The speLC-MS/MS system detected low-femtomole amounts of peptides and allowed sequencing of 1 ?g of HeLa cells protein extracts at a rate of ?90 peptides/min, identifying more than 1500 peptides (>500 proteins) in a 10 min speLC-MS/MS experiment. Analysis by selected reaction monitoring by speLC-SRM-MS/MS of distinct peptides derived from the blood proteins IGF1, IGF2, IBP2, and IBP3 demonstrated protein quantification with CV values below 10% across 96 replicates. The speLC-MS/MS system is ideally suited for fast screening and characterization of large numbers of peptide-containing samples in biological, biomedical, and clinical laboratories.

  20. Selective trace analysis of chloroacetamide herbicides in food samples using dummy molecularly imprinted solid phase extraction based on chemometrics and quantum chemistry

    International Nuclear Information System (INIS)

    Highlights: ? Hyperchem was used to simulate chloroacetamide herbicides and their metabolites. ? Clustering analysis was conducted to analyze the structural data. ? Metolachlor deschloro was selected as the dummy template to synthesize DMIPs. ? The elution order of herbicides on DMIPs was predicted using clustering analysis. ? Compared with other SPE columns, the matrix effect was decreased using DMISPE. - Abstract: A methodology based on chemometrics and quantum chemistry was proposed to design and synthesize dummy molecularly imprinted polymers (DMIPs) capable of extracting chloroacetamide herbicides from food samples. Molecular modeling approach in conjunction with clustering analysis was used to predict the most suitable dummy template. Metolachlor deschloro was selected as the template to synthesize DMIPs, which were used as the solid phase extraction (SPE) materials. The selective adsorption of DMIPs was evaluated by high performance liquid chromatography (HPLC). The retention property of six chloroacetamide herbicides on DMIPs was also predicted using clustering analysis. The optimum loading, washing and eluting conditions for dummy molecularly imprinted solid phase extraction (DMISPE) were established to obtain high selectivity and sensitivity. Water, dichloromethane and methanol were chosen as loading, washing and elution solvent, respectively. Under optimized DMISPE conditions, recoveries of analytes were in the range of 83.4–106.7% with satisfactory precision (RSD% lower than 13%). Compared with other commercial SPE columns, DMISPE exhibited selective binding properties for chloroacetamide herbicides and the matrix effect was significantly decreased.

  1. Isolation of saccharides in dairy and soy products by solid-phase extraction coupled with analysis by ligand-exchange chromatography.

    Science.gov (United States)

    Brereton, Kelsey R; Green, David B

    2012-10-15

    The present study reports an improved method to quickly and reproducibly isolate the saccharides from a variety of dairy and soy products utilizing reversed-phase solid-phase extraction to quantitatively remove fats, fatty acids, and lipids followed by desalination and deproteinization by ion-exchange solid-phase extraction with no loss of saccharides during extraction. Analysis of the isolated saccharides was performed by ligand-exchange HPLC. The method presented requires no prolonged heating (thus protecting the saccharides from hydrolysis or isomerization), uses benign reagents, and realizes a significant time savings over existing methods. The isolation and analysis of monosaccharides (glucose, galactose and fructose), disaccharides (lactose and sucrose), and polysaccharides (raffinose and stachyose) from dairy products (whole, reduced fat, and lactose-free milk and yogurt), infant formula (powdered and premixed), and soy beverages were studied in this investigation with recoveries ranging from 88% to 110% in all products studied. We also applied the method to quickly discriminate authentic soy milk from a soy beverage, branded as soy milk. PMID:23141353

  2. An on-line solid phase extraction-liquid chromatography-tandem mass spectrometry method for the determination of perfluoroalkyl acids in drinking and surface waters.

    Science.gov (United States)

    Mazzoni, Michela; Rusconi, Marianna; Valsecchi, Sara; Martins, Claudia P B; Polesello, Stefano

    2015-01-01

    An UHPLC-MS/MS multiresidue method based on an on-line solid phase extraction (SPE) procedure was developed for the simultaneous determination of 9 perfluorinated carboxylates (from 4 to 12 carbon atoms) and 3 perfluorinated sulphonates (from 4 to 8 carbon atoms). This work proposes using an on-line solid phase extraction before chromatographic separation and analysis to replace traditional methods of off-line SPE before direct injection to LC-MS/MS. Manual sample preparation was reduced to sample centrifugation and acidification, thus eliminating several procedural errors and significantly reducing time-consuming and costs. Ionization suppression between target perfluorinated analytes and their coeluting SIL-IS were detected for homologues with a number of carbon atoms less than 9, but the quantitation was not affected. Total matrix effect corrected by SIL-IS, inclusive of extraction efficacy, and of ionization efficiency, ranged between -34 and +39%. The percentage of recoveries, between 76 and 134%, calculated in different matrices (tap water and rivers impacted by different pollutions) was generally satisfactory. LODs and LOQs of this on-line SPE method, which also incorporate recovery losses, ranged from 0.2 to 5.0?ng/L and from 1 to 20?ng/L, respectively. Validated on-line SPE-LC/MS/MS method has been applied in a wide survey for the determination of perfluoroalkyl acids in Italian surface and ground waters. PMID:25834752

  3. Multiwalled-carbon-nanotubes-based matrix solid-phase dispersion extraction coupled with high-performance liquid chromatography for the determination of honokiol and magnolol in Magnoliae Cortex.

    Science.gov (United States)

    Zhang, Qi; Hong, Bo; Liu, Jianhua; Mu, Guangze; Cong, Huan; Li, Gang; Cai, Defu

    2014-06-01

    In this paper, multiwalled-carbon-nanotube-based matrix solid-phase dispersion coupled to HPLC with diode array detection was used to extract and determine honokiol and magnolol from Magnoliae Cortex. The extraction efficiency of the multiwalled-carbon-nanotube-based matrix solid-phase dispersion was studied and optimized as a function of the amount of dispersing sorbent, volume of elution solvent, and flow rate of elution solvent, with the aid of response surface methodology. An amount of 0.06 g of carboxyl-modified multiwalled carbon nanotubes and 1.5 mL of methanol at a flow rate of 1.1 mL/min were selected. The method obtained good linearity (r(2) > 0.9992) and precision (RSD honokiol and magnolol, with limits of detection of 0.045 and 0.087 ?g/mL, respectively. The recoveries obtained from analyzing in triplicate spiked samples were determined to be from 90.23 to 101.10% and the RSDs from 3.5 to 4.8%. The proposed method that required less samples and reagents was simpler and faster than Soxhlet and maceration extraction methods. The optimized method was applied for analyzing five real samples collected from different cultivated areas. PMID:24616418

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

    Science.gov (United States)

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

    2006-01-01

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

  5. Development of an efficient procedure for the preconcentration of copper(II) after solid phase extraction on modified sawdust

    OpenAIRE

    S. Elhami; M. Sharifi

    2014-01-01

    A sensitive and selective preconcentration method has been developed for copper(II) using modified sawdust as an adsorbent. Sawdust was chemically modified with diethylenetriamine. Copper as CuCl42- was retained by the adsorbent in the column, eluted by nitric acid and subsequently determined by flame atomic absorption spectrometer. The effect of pH, chloride concentration, volume of the sample and diverse ions on the recovery of the analyte was investigated. A preconcentration factor of 250 ...

  6. Preparation, evaluation and application of diazinon imprinted polymers as the sorbent in molecularly imprinted solid-phase extraction and liquid chromatography analysis in cucumber and aqueous samples.

    Science.gov (United States)

    Davoodi, Davood; Hassanzadeh-Khayyat, Mohammad; Rezaei, Mitra Asgharian; Mohajeri, Seyed Ahmad

    2014-09-01

    A series of diazinon imprinted polymers (MIPs) were prepared and evaluated in the binding study in comparison with a non-imprinted polymer (NIP). The optimised MIP was evaluated as a sorbent, for extraction and preconcentration of diazinon from aqueous media and cucumber tissue. The HPLC-UV method was calibrated, in the range of 0.025-10 mg/kg. The results indicated that the optimised MIP had an excellent affinity for diazinon. The molecularly imprinted solid-phase extraction (MISPE) procedure was optimised with a recovery of 77-98%, in aqueous solution, and a recovery of 82-110%, in cucumber. The intra-day variation and inter-day variation values were less than 8.26% and 9.7%, respectively. Our data showed that, the MIP enabled the extraction of trace amounts of diazinon successfully from aqueous solution and cucumber, demonstrating the potential of MISPE for rapid, sensitive and cost-effective sample analysis. PMID:24731364

  7. DEVELOPMENT AND VALIDATION OF A SOLID-PHASE EXTRACTION GAS CHROMATOGRAPHY-MASS SPECTROMETRY METHOD FOR THE SIMULTANEOUS QUANTIFICATION OF OPIOID DRUGS IN HUMAN WHOLE BLOOD AND PLASMA

    Scientific Electronic Library Online (English)

    FELIPE, BRAVO; DIEGO, GONZALEZ; JULIO, BENITES.

    Full Text Available A rapid, selective, sensitive, and specific method is presented to simultaneously quantify morphine, 6-monoacetylmorphine (6-MAM), codeine, heroin, fentanyl, and methadone in human whole blood and plasma. The drugs were extracted with phosphate buffer at pH 6, followed by solid-phase extraction (SPE [...] ) and quantification by GC/MS with electron impact ionization using helium as carrier gas. Quantification was performed based on nalorphine as internal standard (IS). The specificity, linearity, intra- and inter-assay precision and accuracy, and extraction recovery were fully evaluated. The limits of detection (LODs) were 0.40 - 7.63 ng/mL for whole blood and 0.80 - 32.00 ng/mL for plasma. The method is fast, simple, and accurate, with the sensitivity and specificity required in forensic and clinical toxicology.

  8. DEVELOPMENT AND VALIDATION OF A SOLID-PHASE EXTRACTION GAS CHROMATOGRAPHY-MASS SPECTROMETRY METHOD FOR THE SIMULTANEOUS QUANTIFICATION OF OPIOID DRUGS IN HUMAN WHOLE BLOOD AND PLASMA

    Directory of Open Access Journals (Sweden)

    FELIPE BRAVO

    2011-01-01

    Full Text Available A rapid, selective, sensitive, and specific method is presented to simultaneously quantify morphine, 6-monoacetylmorphine (6-MAM, codeine, heroin, fentanyl, and methadone in human whole blood and plasma. The drugs were extracted with phosphate buffer at pH 6, followed by solid-phase extraction (SPE and quantification by GC/MS with electron impact ionization using helium as carrier gas. Quantification was performed based on nalorphine as internal standard (IS. The specificity, linearity, intra- and inter-assay precision and accuracy, and extraction recovery were fully evaluated. The limits of detection (LODs were 0.40 - 7.63 ng/mL for whole blood and 0.80 - 32.00 ng/mL for plasma. The method is fast, simple, and accurate, with the sensitivity and specificity required in forensic and clinical toxicology.

  9. Multiresidue pesticide analysis of botanical dietary supplements using salt-out acetonitrile extraction, solid-phase extraction cleanup column, and gas chromatography-triple quadrupole mass spectrometry.

    Science.gov (United States)

    Hayward, Douglas G; Wong, Jon W; Shi, Feng; Zhang, Kai; Lee, Nathaniel S; DiBenedetto, Alex L; Hengel, Mathew J

    2013-05-01

    Dietary supplements form an increasing part of the American diet, yet broadly applicable multiresidue pesticide methods have not been evaluated for many of these supplements. A method for the analysis of 310 pesticides, isomers, and pesticide metabolites in dried botanical dietary supplements has been developed and validated. Sample preparation involved acetonitrile:water added to the botanical along with anhydrous magnesium sulfate and sodium chloride for extraction, followed by cleanup with solid-phase extraction using a tandem cartridge consisting of graphitized carbon black (GCB) and primary-secondary amine sorbent (PSA). Pesticides were measured by gas chromatography-tandem mass spectrometry. Accuracy and precision were evaluated through fortifications of 24 botanicals at 10, 25, 100, and 500 ?g/kg. Mean pesticide recoveries and relative standard deviations (RSDs) for all botanicals were 97%, 91%, 90%, and 90% and 15%, 10%, 8%, and 6% at 10, 25, 100, and 500 ?g/kg, respectively. The method was applied to 21 incurred botanicals. Quinoxyfen was measured in hops (100-620 ?g/kg). Tetraconazole (48 ?g/kg), tetramethrin (15 ?g/kg), methamidophos (50 ?g/kg), and chlorpyrifos (93 ?g/kg) were measured in licorice, mallow, tea, and tribulus, respectively. Quintozene, its metabolites and contaminants (pentachloroaniline, pentachlorobenzene, pentachloroanisole, and pentachlorothioanisole and hexachlorobenzene and tecnazene, respectively), with hexachlorocyclohexanes and DDT were identified in ginseng sources along with azoxystrobin, diazinon, and dimethomorph between 0.7 and 2800 ?g/kg. Validation with these botanicals demonstrated the extent of this method's applicability for screening 310 pesticides in a wide array of botanical dietary supplements. PMID:23534560

  10. Determination of chiral pharmaceuticals and illicit drugs in wastewater and sludge using microwave assisted extraction, solid-phase extraction and chiral liquid chromatography coupled with tandem mass spectrometry.

    Science.gov (United States)

    Evans, Sian E; Davies, Paul; Lubben, Anneke; Kasprzyk-Hordern, Barbara

    2015-07-01

    This is the first study presenting a multi-residue method allowing for comprehensive analysis of several chiral pharmacologically active compounds (cPACs) including beta-blockers, antidepressants and amphetamines in wastewater and digested sludge at the enantiomeric level. Analysis of both the liquid and solid matrices within wastewater treatment is crucial to being able to carry out mass balance within these systems. The method developed comprises filtration, microwave assisted extraction and solid phase extraction followed by chiral liquid chromatography coupled with tandem mass spectrometry to analyse the enantiomers of 18 compounds within all three matrices. The method was successfully validated for 10 compounds within all three matrices (amphetamine, methamphetamine, MDMA, MDA, venlafaxine, desmethylvenlafaxine, citalopram, metoprolol, propranolol and sotalol), 7 compounds validated for the liquid matrices only (mirtazapine, salbutamol, fluoxetine, desmethylcitalopram, atenolol, ephedrine and pseudoephedrine) and 1 compound (alprenolol) passing the criteria for solid samples only. The method was then applied to wastewater samples; cPACs were found at concentration ranges in liquid matrices of: 1.7 ng L(-1) (metoprolol) - 1321 ng L(-1) (tramadol) in influent,

  11. Peptide-based affinity media for solid-phase extraction of Ochratoxin A from wine samples: Effect of the solid support on binding properties.

    Science.gov (United States)

    Giovannoli, Cristina; Passini, Cinzia; Volpi, Giorgio; Di Nardo, Fabio; Anfossi, Laura; Baggiani, Claudio

    2015-11-01

    A suitable sample clean up is a key point in the development of an analytical method. Peptide-based affinity media have recently gained attention in the selective extraction of defined target analytes from complex samples. In this paper we investigated the thermodynamic and kinetic binding properties of different stationary phases (Amberlite IRC-50, Lewatit CNP105, Toyopearl CM-650 M, porous silica gel beads and micrometric glass beads) functionalized with a hexapeptide sequence binding the Ochratoxin A. The highest values of the equilibrium binding constant (Keq) and binding site concentration (Bmax) were obtained for Lewatit CNP105 (Keq: 98.1×10(6)M(-1), Bmax: 30.8?mol/g), followed by Toyopearl and micrometric glass beads, whereas the worst performances were obtained with Amberlite IRC-50 and porous silica gel beads. Also kinetic performances show the same trend. These results highlight that the surface chemical nature has a key role in the binding properties of solid supports used as affinity media for the selective extraction of well-defined target molecules. Finally, Lewatit CNP105 was compared with Amberlite IRC-50 as solid support in SPE extraction of OTA from 14 wine samples fortified with OTA at 2 and 4?gl(-1) levels. The extracts were analyzed by HPLC with fluorescence detection (?exc 333nm, ?em 460nm) showing no significant matrix effects, with a LOD and LOQ of 0.45 and 1.5?gl(-1), respectively, and good recoveries between 71% and 108% for Amberlite IRC-50 and 91% and 101% for Lewatit CNP105. While both supports showed a statistically comparable extraction accuracy, a statistically significant difference was found in terms of extraction precision, confirming that the solid phase based on Lewatit CNP105 performs better than the solid phase based on Amberlite IRC-50. PMID:26452853

  12. Development of a group selective molecularly imprinted polymers based solid phase extraction of malachite green from fish water and fish feed samples

    International Nuclear Information System (INIS)

    A group selective molecularly imprinted solid phase extraction (MISPE) for malachite green (MG) from fish water and fish feed samples was developed. Using MG as template molecule, methacrylic acid as functional monomer, ethylene glycoldimethacrylate as linking agent and bulk polymerization as synthetic method, the molecularly imprinted polymers (MIPs) were synthesized and characterized with rebinding experiment. The Scatchard polt's analysis revealed that the template-polymer system showed the two-site binding behavior with dissociation constants of 0.3194 ?mol L-1 and 15.70 ?mol L-1, respectively. MG and two structurally related compounds, leucomalachite green (LMG) and crystal violet (CV) were employed for selectivity test. The MIPs exhibited the highest selective rebinding to MG, but also displayed 83.0% and 87.5% of cross-reactivity with LMG and CV, demonstrating that MIPs could be used as group recognition sorbents in solid phase extraction. The extraction conditions of MISPE column for MG were optimized. Tap water samples spiked with MG at concentration of 0.5-10 ng mL-1 were extracted by MISPE column and analyzed by high performance liquid chromatography. The recoveries of MISPE column for MG extraction were found to be 76.8-93.7% with the relative standard deviations of 2.12-10.09%, indicating the feasibility of the prepared MIPs for MG extraction. No detectable MG was observed in one fish farming water sample and two fish feed samples; while the MG concentrations in two pet fishpond water samples were found at 1.50 ng mL-1 and 0.67 ng mL-1, respectively

  13. Study on solid phase extraction and spectrophotometric determination of vanadium with 2,3-dichloro-6-(2,7-dihydroxy-1-naphthylazo)quinoxaline

    Science.gov (United States)

    Amin, Alaa S.; Saber, Amr L.; Mohammed, T. Y.

    2009-07-01

    A sensitive, selective and rapid method has been developed for the determination micrograms per liter level of vanadium ion based on the rapid reaction of vanadium(V) with 2,3-dichloro-6-(2,7-dihydroxy-1-naphthylazo)quinoxaline (DCDHNAQ) and the solid phase extraction of the colored complex with C18 cartridge. The DCDHNAQ reacts with V(V) in the presence of citric acid-sodium hydroxide buffer solution (pH 3.3) and benzyldimethyl tetradecylammonium chloride (zephiramine) medium to form a violet complex of a molar ratio 1:2 [V(V) to DCDHNAQ]. This complex was enriched by solid phase extraction with C18 cartridge and the enrichment factor of 100 was obtained by elution of the complex from the cartridge with acetonitrile. The molar absorptivity and Sandell sensitivity of the complex are 2.45 × 10 5 L mol -1 cm -1 and 0.0208 ng cm -2 at 573 nm in the measured solution. Beer's law is obeyed in the range of 0.01-0.45 ?g mL -1, whereas Ringbom optimum concentration ranges found to be 0.025-0.425 ?g mL -1. The detection and quantification limits are 3.2 and 9.9 ?g L -1, respectively in the original samples. This method was applied to the determination of vanadium(V) in steel, soil, water and biological samples with good results.

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

    Science.gov (United States)

    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 ?). 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.

  15. Simultaneous determination of five minor coumarins and flavonoids in Glycyrrhiza uralensis by solid-phase extraction and high-performance liquid chromatography/electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Qiao, Xue; Liu, Chun-Fang; Ji, Shuai; Lin, Xiong-Hao; Guo, De-An; Ye, Min

    2014-02-01

    Minor phenolic compounds in licorice (Glycyrrhiza uralensis) have recently been proved for diverse bioactivities and favorable bioavailability, indicating that they may play an important role in the therapeutic effects or herb-drug interactions of licorice. However, so far, their abundance in licorice remains unknown. In this study, a reliable solid-phase extraction coupled with a high-performance liquid chromatography and diode array detection method was established to determine the minor phenolic compounds in licorice. The analytes were enriched by a three-step solid-phase extraction method, and then separated on a YMC ODS-A column by gradient elution. Five coumarins and flavonoids were identified by electrospray ionization tandem mass spectrometry, and then quantified using high-performance liquid chromatography and diode array detection. The amounts of glycycoumarin, dehydroglyasperin C, glycyrol, licoflavonol, and glycyrin in G. uralensis were 0.81?±?0.28, 1.25?±?0.59, 0.20?±?0.08, 0.12?±?0.04, and 0.17?±?0.08?mg/g, respectively. Abundances of these compounds in other Glycyrrhiza species (G. glabra, G. inflata, and G. yunnanesis) were remarkably lower than G. uralensis. PMID:24496986

  16. New method based on combining ultrasonic assisted miniaturized matrix solid-phase dispersion and homogeneous liquid-liquid extraction for the determination of some organochlorinated pesticides in fish

    International Nuclear Information System (INIS)

    Highlights: ? Ultrasonic assisted miniaturized matrix solid-phase dispersion combined with HLLE was developed as a new method for the extraction of OCPs in fish. ? The goal of this combination was to enhance the selectivity of HLLE procedure and to extend its application in biological samples. ? This method proposed the advantages of good detection limits, lower consumption of reagents, and does not need any special instrumentation. - Abstract: In this study, ultrasonic assisted miniaturized matrix solid-phase dispersion (US-MMSPD) combined with homogeneous liquid-liquid extraction (HLLE) has been developed as a new method for the extraction of organochlorinated pesticides (OCPs) in fish prior to gas chromatography with electron capture detector (GC-ECD). In the proposed method, OCPs (heptachlor, aldrin, DDE, DDD, lindane and endrin) were first extracted from fish sample into acetonitrile by US-MMSPD procedure, and the extract was then used as consolute solvent in HLLE process. Optimal condition for US-MMSPD step was as follows: volume of acetonitrile, 1.5 mL; temperature of ultrasound, 40 deg. C; time of ultrasound, 10 min. For HLLE step, optimal results were obtained at the following conditions: volume of chloroform, 35 ?L; volume of aqueous phase, 1.5 mL; volume of double distilled water, 0.5 mL; time of centrifuge, 10 min. Under the optimum conditions, the enrichment factors for the studied compounds were obtained in the range of 185-240, and the overall recoveries were ranged from 39.1% to 81.5%. The limits of detection were 0.4-1.2 ng g-1 and the relative standard deviations for 20 ng g-1 of the OCPs, varied from 3.2% to 8% (n = 4). Finally, the proposed method has been successfully applied to the analysis of the OCPs in real fish sample, and satisfactory results were obtained.

  17. New method based on combining ultrasonic assisted miniaturized matrix solid-phase dispersion and homogeneous liquid-liquid extraction for the determination of some organochlorinated pesticides in fish

    Energy Technology Data Exchange (ETDEWEB)

    Rezaei, Farahnaz [Department of Analytical Chemistry, Faculty of Chemistry, Iran University of Science and Technology, Narmak, Tehran 16846 (Iran, Islamic Republic of); Hosseini, Mohammad-Reza Milani, E-mail: drmilani@iust.ac.ir [Department of Analytical Chemistry, Faculty of Chemistry, Iran University of Science and Technology, Narmak, Tehran 16846 (Iran, Islamic Republic of); Electroanalytical Chemistry Research Center, Iran University of Science and Technology, Narmak, Tehran 16846 (Iran, Islamic Republic of)

    2011-09-30

    Highlights: {yields} Ultrasonic assisted miniaturized matrix solid-phase dispersion combined with HLLE was developed as a new method for the extraction of OCPs in fish. {yields} The goal of this combination was to enhance the selectivity of HLLE procedure and to extend its application in biological samples. {yields} This method proposed the advantages of good detection limits, lower consumption of reagents, and does not need any special instrumentation. - Abstract: In this study, ultrasonic assisted miniaturized matrix solid-phase dispersion (US-MMSPD) combined with homogeneous liquid-liquid extraction (HLLE) has been developed as a new method for the extraction of organochlorinated pesticides (OCPs) in fish prior to gas chromatography with electron capture detector (GC-ECD). In the proposed method, OCPs (heptachlor, aldrin, DDE, DDD, lindane and endrin) were first extracted from fish sample into acetonitrile by US-MMSPD procedure, and the extract was then used as consolute solvent in HLLE process. Optimal condition for US-MMSPD step was as follows: volume of acetonitrile, 1.5 mL; temperature of ultrasound, 40 deg. C; time of ultrasound, 10 min. For HLLE step, optimal results were obtained at the following conditions: volume of chloroform, 35 {mu}L; volume of aqueous phase, 1.5 mL; volume of double distilled water, 0.5 mL; time of centrifuge, 10 min. Under the optimum conditions, the enrichment factors for the studied compounds were obtained in the range of 185-240, and the overall recoveries were ranged from 39.1% to 81.5%. The limits of detection were 0.4-1.2 ng g{sup -1} and the relative standard deviations for 20 ng g{sup -1} of the OCPs, varied from 3.2% to 8% (n = 4). Finally, the proposed method has been successfully applied to the analysis of the OCPs in real fish sample, and satisfactory results were obtained.

  18. Investigation of cell culture volatilomes using solid phase micro extraction: Options and pitfalls exemplified with adenocarcinoma cell lines.

    Science.gov (United States)

    Schallschmidt, Kristin; Becker, Roland; Jung, Christian; Rolff, Jana; Fichtner, Iduna; Nehls, Irene

    2015-12-01

    Three strategies to sample volatile organic compounds (VOC) from lung cancer cell lines cultured in vitro were compared. Headspace solid phase microextraction was applied in situ to culture flasks and alternatively to subsamples of headspace gas or to nutrient solution subsamples followed by gas chromatography-mass spectrometry. The direct quantification of 55 VOC in the headspace of cell cultures was validated and is discussed with respect to reproducibility and system-related interferences. The role of the VOC background from culture media and usually employed polystyrene culture vessels is examined and was seen to invoke potentially misleading conclusions. The commercial A549 and two further adenocarcinoma cell lines displayed largely similar VOC profiles with distinct differences regarding certain individual substances. There is evidence for the inappropriateness of the standard cell culturing methods in the search for volatile cancer markers. PMID:26551208

  19. Automated solid-phase extraction coupled online with HPLC-FLD for the quantification of zearalenone in edible oil.

    Science.gov (United States)

    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 limit of quantification, 30 ?g/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

  20. Novel molecularly imprinted polymers with carbon nanotube as matrix for selective solid-phase extraction of emodin from kiwi fruit root.

    Science.gov (United States)

    Yang, Xiao; Zhang, Zhaohui; Li, Jiaxing; Chen, Xing; Zhang, Minlei; Luo, Lijuan; Yao, Shouzhuo

    2014-02-15

    In this paper, we present a novel surface imprinting technique for the preparation of molecularly imprinted polymers/multi-walled carbon nanotubes (MIPs/MWNTs) for extraction of emodin from kiwi fruit root. The MIPs/MWNTs were characterised by scanning electron microscopy (SEM) and Fourier transform-infrared spectroscopy (FT-IR). The properties involving adsorption dynamics, static adsorption, and selective recognition capacity were evaluated. The MIPs/MWNTs exhibited good site accessibility in which it only took 60 min to achieve adsorption equilibrium and highly selective recognition for the template emodin. Furthermore, the performance of the MIPs/MWNTs as solid phase extraction (SPE) material was investigated in detail. The proposed MIPs/MWNTs-SPE procedure for emodin exhibited satisfactory recoveries ranging from 89.2% to 93.8% for real samples. It was used for the purification and enrichment of emodin from kiwi fruit root successfully. PMID:24128532

  1. Dithizone-modified nanoporous fructose as a novel sorbent for solid-phase extraction of ultra-trace levels of heavy metals

    International Nuclear Information System (INIS)

    We are introducing nanoporous fructose (np-F) modified with dithizone as a new solid-phase for extraction of heavy metals ions including cadmium(II), copper(II), nickel(II) and lead(II). Effects of pH value, flow rates, type, concentration and volume of the eluent, breakthrough volume, and of other ions were studied. Under optimized conditions, the extraction efficiency is >97 %, and the limits of detection are 0.025, 0.15, 0.5 and 1.2 ng mL?1 for the ions of cadmium, copper, nickel, and lead, respectively, and the adsorption capacities for these ions are 101, 81, 74 and 178 mg g?1. The modified np-F sorbent was characterized by thermogravimetric analysis, differential thermal analysis, transmission electron microscopy, Fourier transform infrared spectrometry, X-ray diffraction, and nitrogen adsorption surface area (BET) measurements. (author)

  2. Portable Solid Phase Micro-Extraction Coupled with Ion Mobility Spectrometry System for On-Site Analysis of Chemical Warfare Agents and Simulants in Water Samples

    Directory of Open Access Journals (Sweden)

    Liu Yang

    2014-11-01

    Full Text Available On-site analysis is an efficient approach to facilitate analysis at the location of the system under investigation as it can result in more accurate, more precise and quickly available analytical data. In our work, a novel self-made thermal desorption based interface was fabricated to couple solid-phase microextraction with ion mobility spectrometry for on-site water analysis. The portable interface can be connected with the front-end of an ion mobility spectrometer directly without other modifications. The analytical performance was evaluated via the extraction of chemical warfare agents and simulants in water samples. Several parameters including ionic strength and extraction time have been investigated in detail. The application of the developed method afforded satisfactory recoveries ranging from 72.9% to 114.4% when applied to the analysis of real water samples.

  3. Portable Solid Phase Micro-Extraction Coupled with Ion Mobility Spectrometry System for On-Site Analysis of Chemical Warfare Agents and Simulants in Water Samples

    Science.gov (United States)

    Yang, Liu; Han, Qiang; Cao, Shuya; Yang, Jie; Yang, Junchao; Ding, Mingyu

    2014-01-01

    On-site analysis is an efficient approach to facilitate analysis at the location of the system under investigation as it can result in more accurate, more precise and quickly available analytical data. In our work, a novel self-made thermal desorption based interface was fabricated to couple solid-phase microextraction with ion mobility spectrometry for on-site water analysis. The portable interface can be connected with the front-end of an ion mobility spectrometer directly without other modifications. The analytical performance was evaluated via the extraction of chemical warfare agents and simulants in water samples. Several parameters including ionic strength and extraction time have been investigated in detail. The application of the developed method afforded satisfactory recoveries ranging from 72.9% to 114.4% when applied to the analysis of real water samples. PMID:25384006

  4. Titanium dioxide nanotubes for solid phase extraction of benzoylurea insecticides in environmental water samples, and determination by high performance liquid chromatography with UV detection

    International Nuclear Information System (INIS)

    A new, simple and sensitive method was established for solid-phase extraction of benzoylurea insecticides including diflubenzuron, chlorbenzuron, triflumuron, flufenoxuron, and chlorfluazuron in water samples using TiO2 nanotubes cartridge prior to their determination by liquid chromatography. The parameters influencing the extraction were investigated and optimized. Under optimal conditions, a good linearity was found between the concentration and the peak area in the range from 0.2 to 40 ?g L-1 (r2 > 0.99), and detection limits were in the range from 0.062 to 0.21 ?g L-1. Real water samples were used for validating the method and recoveries of spiked samples were over the range from 82.0 to 100%. The results indicated that TiO2 nanotubes represented an attractive alternative sorbent for the enrichment and trace analysis of such pollutants. (author)

  5. A fast method for the determination of Sr-90 in liquid milk by solid phase extraction with cryptand 222 on cation exchange resin

    International Nuclear Information System (INIS)

    A method for determining the activity of Sr-90 in liquid milk samples that does not require the usual drying, ashing, acid leaching and precipitation procedures is described. Two solid phase extractants are used, namely: Cryptand 222 bound to a cation exchange resin, and Eichrome Industries' Sr.Spec Resin trademark. These are applied respectively to extract Sr-90 from the milk and to isolate it in a form suitable for measurement by low-level liquid scintillation counting. The results of analyses of 1 liter milk samples contaminated with a known activity of Sr-90 agreed well with the expected values. It was also found that Sr.Spec Resin trademark can be regenerated and re-used several times. As the method requires only minimal operator skill and time, many samples can be analyzed simultaneously. (orig.)

  6. Automated on-line solid phase extraction coupled to HPLC-APCI-MS detection as a versatile tool for the analysis of phenols in water samples

    International Nuclear Information System (INIS)

    In this work a liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (HPLC-APCI-MS) technique was developed for the determination of phenols and anilines in waste water samples. All relevant parameters were optimized for liquid chromatographic (LC) separation and mass spectrometric (MS) detection. Mass spectrometric detection was used in either negative ionization (NI) or positive ionization (PI) mode, which was depending on the physicochemical properties of the analyte. For screening analysis, full scan mode (SCAN) was used, while selected ion monitoring (SIM) mode of acquisition was used for maximum sensitivity. The optimal interface parameters and solvent compositions were evaluated, which mainly determined the ionization of analytes thus strongly influencing the sensitivity. The quasi-molecular ions were the most abundant signals both for phenols ([M-H]- in NI) and for anilines ([M+H]+ in PI). In general, fragmentation was hardly observed for one-ring phenols. Only fragmentation due to neutral losses of NO, HCl, NH3, CO2, CHO or CO from the functional groups were obtained via collision induced dissociation (CID) in a single quadrupole mass spectrometer. A further source of structural information was the relative intensity of positive and negative ions for one analyte: Only in the case of para-methyl substituted phenols, detection was also possible in positive ionization mode with reasonable sensitivity. In contrast to the phenols, anilines offered somewhat higher structural information due to increased fragmentation through CID, when detected in the positive ionization mode. The main goal of this work was the development of a method for the determination of US EPA priority phenols in different environmental matrices. As highest sensitivity and selectivity was required for this task, a preconcentrating step was necessary, and consequently solid phase extraction (SPE) was coupled on-line to HPLC-APCI-MS. The optimized method allowed the determination of the entire US EPA phenol range within a single chromatographic run with only one MSD interface and could be easily adapted for the analysis of further phenolic compounds. This represents a significant improvement over methods reported for the analysis of phenolic compounds by on-line SPE HPLC-MS so far. For the on-line SPE of phenols from water samples the recently introduced Hysphere GP and the Waters Oasis adsorbent materials were found to be most satisfactory. Their application resulted in quantitative recoveries for sample volumes up to 100 ml, excellent elution behavior (enabling fast elution resulting in narrower peaks) and relative standard deviations for the overall analysis system below 8 percent for all phenols. Typical enrichment factors for automated on-line SPE were estimated to be about one thousand compared to autosampler-injections. Thus, LODs ranging between 40-280 ng/l in SCAN mode could be achieved even when only 10 ml of spiked distilled or river water sample were processed which attests to the excellent screening capabilities of the optimized method. When using the SIM mode the sensitivity could be further increased by about one order of magnitude. The applicability of the proposed method to environmental analysis was demonstrated by preconcentrating phenols from spiked river water samples or waster water treatment effluents via automated on-line SPE HPLC-MS. Due to the very high concentration of matrix in the case of waste water treatment effluents, the sample volume preconcentrated had to be decreased to only 1 ml. Still, the sensitivity is high enough to monitor phenols at levels relevant for waste water monitoring. As a further example for the general applicability of the HPLC-MS method for the tentative structural elucidation of phenolic compounds, it was also used for the analysis of diesel exhaust condensate samples where a number of phenolic compounds could be tentatively identified. (author)

  7. Simultaneous Determination of Parathion, Malathion, Diazinon, and Pirimiphos Methyl in Dried Medicinal Plants Using Solid-Phase Microextraction Fibre Coated with Single-Walled Carbon Nanotubes

    OpenAIRE

    Ahmadkhaniha, Reza; Samadi, Nasrin; Salimi, Mona; Sarkhail, Parisa; Rastkari, Noushin

    2012-01-01

    A reliable and sensitive headspace solid-phase microextraction gas chromatography-mass spectrometry method for simultaneous determination of different organophosphorus pesticides in dried medicinal plant samples is described. The analytes were extracted by single-walled carbon nanotubes as a new solid-phase microextraction adsorbent. The developed method showed good performance. For diazinon and pirimiphos methyl calibration, curves were linear (r2 ? 0.993) over the concentration ranges from ...

  8. Application of solid-phase micro extraction for the determination of pesticides in vegetable samples by gas chromatography with an electron capture detector

    International Nuclear Information System (INIS)

    A solid-phase micro extraction (SPME) method has been developed for the determination of 9 pesticides in 2 vegetables -cucumber and tomato - samples, based on direct immersion mode and subsequent desorption into the injection port of a gas chromatograph with an electron capture detector (GC-ECD). The main factors affecting the SPME process such as extraction time and temperature, desorption time and temperature, the effect of salt addition and fiber depth into the liner were studied and optimized. The analytical procedure proposed consisted of a 30 minute ultrasonic extraction of the target compounds from 1.0 g vegetable samples with 5 mL of distilled water. Then, the samples were filtered and topped up with distilled water to 10 mL. The analytes in this aqueous extract were extracted for 15 minutes with a 100 ?m thickness polydimethylsiloxane SPME fiber. Relative standard deviations for triplicate analyses of samples were less than 10 %. The recoveries of the pesticides studied in cucumber and tomato ranged from 52 % to 82 % and the RSD were below 10 %. Therefore, the proposed method is applicable in the analysis of pesticides in vegetable matrices. SPME has been shown to be a simple extraction technique, which has a number of advantages such as solvent free extraction, simplicity and compatibility with the chromatographic analytical system. (author)

  9. Preparation of magnetic chitosan and graphene oxide-functional guanidinium ionic liquid composite for the solid-phase extraction of protein.

    Science.gov (United States)

    Ding, Xueqin; Wang, Yuzhi; Wang, Ying; Pan, Qi; Chen, Jing; Huang, Yanhua; Xu, Kaijia

    2015-02-25

    A series of novel cationic functional hexaalkylguanidinium ionic liquids and anionic functional tetraalkylguanidinium ionic liquids have been synthesized, and then magnetic chitosan graphene oxide (MCGO) composite has been prepared and coated with these functional guanidinium ionic liquids to extract protein by magnetic solid-phase extraction. MCGO-functional guanidinium ionic liquid has been characterized by vibrating sample magnetometer, field emission scanning electron microscopy, X-ray diffraction spectrometer and Fourier transform infrared spectrometer. After extraction, the concentrations of protein were determined by measuring the absorbance at 278 nm using an ultra violet visible spectrophotometer. The advantages of MCGO-functional guanidinium ionic liquid in protein extraction were compared with magnetic chitosan, graphene oxide, MCGO and MCGO-ordinary imidazolium ionic liquid. The proposed method has been applied to extract trypsin, lysozyme, ovalbumin and bovine serum albumin. A comprehensive study of the adsorption conditions such as the concentration of protein, the amount of MCGO-functional guanidinium ionic liquid, the pH, the temperature and the extraction time were also presented. Moreover, the MCGO-functional guanidinium ionic liquid can be easily regenerated, and the extraction capacity was about 94% of the initial one after being used three times. PMID:25702272

  10. Focused microwave-assisted extraction combined with solid-phase microextraction and gas chromatography-mass spectrometry for the selective analysis of cocaine from coca leaves.

    Science.gov (United States)

    Bieri, Stefan; Ilias, Yara; Bicchi, Carlo; Veuthey, Jean-Luc; Christen, Philippe

    2006-04-21

    An effective combination of focused microwave-assisted extraction (FMAE) with solid-phase microextraction (SPME) prior to gas chromatography (GC) is described for the selective extraction and quantitative analysis of cocaine from coca leaves (Erythroxylum coca). This approach required switching from an organic extraction solvent to an aqueous medium more compatible with SPME liquid sampling. SPME was performed in the direct immersion mode with a universal 100 microm polydimethylsiloxane (PDMS) coated fibre. Parameters influencing this extraction step, such as solution pH, sampling time and temperature are discussed. Furthermore, the overall extraction process takes into account the stability of cocaine in alkaline aqueous solutions at different temperatures. Cocaine degradation rate was determined by capillary electrophoresis using the short end injection procedure. In the selected extraction conditions, less than 5% of cocaine was degraded after 60 min. From a qualitative point of view, a significant gain in selectivity was obtained with the incorporation of SPME in the extraction procedure. As a consequence of SPME clean-up, shorter columns could be used and analysis time was reduced to 6 min compared to 35 min with conventional GC. Quantitative results led to a cocaine content of 0.70 +/- 0.04% in dry leaves (RSD <5%) which agreed with previous investigations. PMID:16384568

  11. Aplicação de SPME (Solid Phase Micro-Extraction) na análise de águas potáveis de três localidades do estado de São Paulo / Application of SPME (Solid Phase Micro-Extraction) to the analysis of drinkable water from three locations in the state of São Paulo

    Scientific Electronic Library Online (English)

    Antonio Luiz Pires, Valente; Fabio, Augusto; Larisse, Montero; Eduardo Carasek da, Rocha; Janusz, Pawliszyn.

    1998-11-01

    Full Text Available [...] Abstract in english The technique of solid phase microextraction (SPME) was used for the extraction of halogenated contaminants of water samples from three cities of the State of São Paulo and the extracts were submitted to gas chromatographic analysis with electron capture detection (GC-ECD). In the samples of water c [...] ollected at the city of São Paulo the detected level of trihalomethanes (THM) expressed as the sum of chloroform, dibromochloromethane and dichlorobromomethane, were higher than the permissible limit established by the Brazilian regulation. In the samples collected at the two other cities the level of any of the three THM remained below the sensitivity of the ECD.

  12. Silica chemically bonded N-propyl kriptofix 21 and 22 with immobilized palladium nanoparticles for solid phase extraction and preconcentration of some metal ions

    Energy Technology Data Exchange (ETDEWEB)

    Ghaedi, Mehrorang, E-mail: m_ghaedi@mail.yu.ac.ir [Chemistry Department, Yasouj University, Yasouj, 75914-353 (Iran, Islamic Republic of); Niknam, Khodabakhsh, E-mail: niknam@pgu.ac.ir [Chemistry Department, Faculty of Sciences, Persian Gulf University, Bushehr, 75169 (Iran, Islamic Republic of); Zamani, Saeed; Abasi Larki, Habib [Chemistry Department, Islamic Azad University, Omidiyeh Branch, Omidiyeh (Iran, Islamic Republic of); Roosta, Mostafa [Chemistry Department, Yasouj University, Yasouj, 75914-353 (Iran, Islamic Republic of); Soylak, Mustafa [Chemistry Department, University of Erciyes, 38039 Kayseri (Turkey)

    2013-08-01

    Silica gel chemically bonded N-propyl kriptofix 21 (SBNPK 21) and N-propyl kriptofix 22 (SBNPK 22) and subsequently immobilized with palladium nanoparticles (PNP-SBNPK 21 and PNP-SBNPK 22) to produce two new complexing lipophilic materials. Then these novel sorbents were applied for the enrichment of some metal ions and their subsequent determination by flame atomic absorption spectroscopy (FAAS). The influences of the variables including pH, amount of solid phase, sample flow rate, eluent conditions and sample volume on the metal ion recoveries were investigated. The detection limit of proposed method was in the interval 2.1–2.3 and 1.7–2.8 ng mL{sup ?1} for PNP-SBNPK 21 and PNP-SBNPK 22 respectively, while the preconcentration factor was 80 for two sorbents. The relative standard deviations of recoveries were between 1.23–1.31 and 1.28–1.49 for PNP-SBNPK 21 and PNP-SBNPK 22 respectively. The method has high sorption-preconcentration efficiency even in the presence of various interfering ions. Due to the reasonable selectivity of proposed method, the relative standard deviation of recoveries of all understudied metal ions in some complicated matrices was less than 3.0%. Highlights: • Highly selective sorbents for solid phase extraction were synthesized. • The method has been successfully applied for the determination of trace metals ions. • Excellent properties of the sorbent have been illustrated in detail.

  13. Cation-exchange solid-phase and liquid-liquid extraction for the determination of khat alkaloids by reversed phase HPLC-DAD

    Directory of Open Access Journals (Sweden)

    M. Atlabachew

    2015-10-01

    Full Text Available Leaves of khat (Catha edulis are masticated to elicit their psycho-stimulating properties, resulting from the presence of the phenylpropylamino alkaloids. The determination of these alkaloids is important in pharmacological, phytochemical, forensic and law enforcement environments. In this study, the use of strong cation exchange-solid phase extraction (SCX-SPE was investigated as an alternative means of sample purification prior to the determination of cathinone, cathine and norephedrine by reversed phase (C18 high performance liquid chromatography (HPLC. Extraction parameters for SCX, including loading capacity and washing solvents, were established. An existing liquid-liquid extraction (LLE method was improved in terms of recoveries obtained, by using ethyl acetate as extractant. For pure standards of the khat alkaloids, recoveries ranged from 83 to 97%. Preconcentration, using a Genevac evaporator after the addition of acidified water to the sample, restricted analyte losses when compared to concentration under nitrogen. Although comparable recoveries were obtained when preconcentration was achieved in the presence of acidified water by rotary evaporation, this method is not suitable for large sample numbers. Best recoveries, ranging from 94 to 102%, were obtained by SCX from spiked samples. Although the extraction efficiencies of LLE were lower (87-90%, LLE yielded less complex chromatograms, indicating a purer extract.DOI: http://dx.doi.org/10.4314/bcse.v29i3.1

  14. Determination of bisphenols in beverages by mixed-mode solid-phase extraction and liquid chromatography coupled to tandem mass spectrometry.

    Science.gov (United States)

    Regueiro, Jorge; Wenzl, Thomas

    2015-11-27

    Facing growing restrictions on the use of bisphenol A in food contact materials, several bisphenol analogs are arising as major alternatives to replace this chemical in most of its applications. This work reports a simple and robust method based on mixed-mode solid-phase extraction and stable-isotope dilution liquid chromatography-tandem mass spectrometry for the analysis of bisphenol A and its main analogs - bisphenol S, 4,4'-sulfonylbis(2-methylphenol), bisphenol F, bisphenol E, bisphenol B, bisphenol Z, bisphenol AF, bisphenol AP, tetrabromobisphenol A and bisphenol P - in alcoholic and non-alcoholic beverages. Mixed-mode solid-phase extraction, combining cationic exchange and reversed-phase mechanisms, was optimized to provide a selective extraction and purification of the target analytes. Derivatization of bisphenols with pyridine-3-sulfonyl chloride allowed increasing their ionization efficiency by electrospray ionization. Validation of the proposed method was performed in terms of selectivity, matrix effects, linearity, precision, measurement uncertainty, trueness and limits of detection. Satisfactory repeatability and intermediate precision were obtained; the related relative standard deviations were ?9% and ?12%, respectively. The relative expanded uncertainty (k=2) was below 20% for all bisphenol analogs and the trueness of the method was demonstrated by recovery experiments. Limits of detection (LOD) ranged from 1.6ngL(-1) to 27.9ngL(-1) for all compounds. Finally, several canned and non-canned beverages were analyzed to demonstrate the applicability of the method. Only bisphenol A and three bisphenol F isomers were detected in any of the samples. Bisphenol A concentration ranged from beverages, at concentration levels up to 0.12 and 0.51?gL(-1), respectively. PMID:26525665

  15. A novel mixed-mode solid phase extraction for simultaneous determination of melamine and cyanuric acid in food by hydrophilic interaction chromatography coupled to tandem mass chromatography.

    Science.gov (United States)

    Deng, Xiao-Jun; Guo, De-Hua; Zhao, Shan-Zhen; Han, Li; Sheng, Yong-Gang; Yi, Xiong-Hai; Zhou, Yao; Peng, Tao

    2010-10-15

    Utilizing a solid phase extraction column (MCT) containing mixed hydrophilic functional gel and cation exchange sorbent, a sensitive and rapid HPLC-MS/MS method for simultaneously determining the residues of melamine (MEL) and cyanuric acid (CYA) in human foodstuffs was developed. MEL and CYA in egg, pork, liver, kidney and pork, shrimp, sausage casing, honey, soybean milk, soybean powder and dairy product were extracted using acetonitrile/water, defatted with hexane and isolated using MCT solid phase extraction column. The residues were separated upon a hydrophilic interaction liquid chromatography (HILIC) column and analyzed by electrospray ionization under negative-positive switched mode on a triplequadrupole mass spectrometry. The selected reaction monitoring was performed on [M+H](+) of m/z 127.9 to provide the transition of 127>85 and 127>68 (MEL) while the [M-H](-) of m/z 127.1 was selected as the precursor ion for CYA resulting in product ions m/z 85 and 42. Isotope labeled internal standard ((15)N(3)-MEL and (13)C(3)-CYA) and matrix-matched calibration were both used to observe the recovery to be 70.0-129.6% and 70.0-128.9% with RSD of 1.4-23.3% and 1.5-21.7% for MEL and CYA, respectively (n=6). All the LODs and LOQs of MEL and CYA were less than 39.4 and 99.1?gkg(-1), respectively, in 18 matrices, which were sensitive enough for quantitative analysis. This method has been proven effective in simultaneous determination of melamine and cyanuric acid when inspecting unknown and positive samples. PMID:20850393

  16. Development of an efficient procedure for the preconcentration of copper(II after solid phase extraction on modified sawdust

    Directory of Open Access Journals (Sweden)

    S. Elhami

    2014-09-01

    Full Text Available A sensitive and selective preconcentration method has been developed for copper(II using modified sawdust as an adsorbent. Sawdust was chemically modified with diethylenetriamine. Copper as CuCl42- was retained by the adsorbent in the column, eluted by nitric acid and subsequently determined by flame atomic absorption spectrometer. The effect of pH, chloride concentration, volume of the sample and diverse ions on the recovery of the analyte was investigated. A preconcentration factor of 250 was achieved using optimum conditions. The calibration graph was linear in the range 1-150 ng mL-1 copper in the initial solution. The detection limit (3Sb was 0.2 ng mL-1 and the relative standard deviations were 2.7 and 1.2% for 5 and 50 ng mL-1 respectively (n = 10. It was revealed that after ten cycles of adsorption and desorption, the adsorbent retained its promising adsorption ability. The method was successfully applied to the determination of copper(II in different water samples. Obtained results showed that the developed method is relatively simple, accurate, sensitive and selective. DOI: http://dx.doi.org/10.4314/bcse.v28i3.1

  17. A novel dispersive micro solid phase extraction using PCX as the sorbent for the determination of melamine and cyromazine in milk and milk powder by UHPLC-HRMS/MS.

    Science.gov (United States)

    Chen, Dawei; Zhao, Yunfeng; Miao, Hong; Wu, Yongning

    2015-03-01

    A novel dispersive micro solid phase extraction (DMSPE) cleanup method based on the PCX sorbent (a kind of cation exchange polymer material) was applied to the analysis of melamine and cyromazine residues in milk and milk powder, and ultra high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) was used as instrument detection. Milk powder samples were first extracted with 1% formic acid in acetonitrile/water (1:1 v/v), and milk samples were cleaned up directly without any pre-extraction. Then, melamine and cyromazine in the extracts or milk were adsorbed to the PCX powder. Subsequently, the analytes in PCX sorbent were eluted with ammonium hydroxide/acetonitrile (2.5:97.5 v/v) through a simple unit device equipped with 1 mL syringe and 0.22 ?m nylon syringe filter. All the samples were analyzed by UHPLC-HRMS/MS on a Waters Acquity BEH HILIC column with 0.1% formic acid and 4mM ammonium formate in water/acetonitrile as the mobile phase with gradient elution. The matrix effect, recovery, and repeatability, within laboratory reproducibility, CC? and CC? of the DMSPE cleanup method were investigated. The proposed method provided a significant improvement for the determination of melamine and cyromazine in milk and milk powder in terms of efficient, rapid, economical, and miniaturized sample preparation methods, which yielded fewer matrix effects compared with SPE method. The established cleanup method is expected to be widely applied for the sample preparation of alkaline contaminants at trace levels in the future. PMID:25618651

  18. A solid-phase extraction method for analyzing trace amounts of polychlorinated dibenzo-p-dioxins and dibenzofurans in waste water

    Directory of Open Access Journals (Sweden)

    Hye-Sung Cho

    2011-03-01

    Full Text Available The Korean government has regulated emission of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fsin waste water of manufacturing facilities producing chlorinated compounds since 2009. As this regulation is expected to bereinforced in 2013 to 50 pg I-TEQ/L, a large sample volume is required for the analysis of trace amounts of PCDD/Fs in wastewater. Liquid-liquid extraction (LLE is used to extract PCDD/Fs from aqueous samples; however, its low efficiency makes itinadequate for analyzing large sample volumes. Herein, we present a disk-type solid-phase extraction (SPE method for the analysisof dioxin at a part per quadrillion level in waste water. This SPE system contains airtight glass covers with a decompressionpump, which enables continuous semi-automated extraction. Small (0.5 L and large (7 L samples were extracted using LLE andSPE methods, respectively. The method detection limits (MDLs were 0.001?0.25 and 0.015?4.1 pg I-TEQ/L for the SPE andLLE methods, respectively. The concentrations of detected congeners with both methods were similar. However, the concentrationsof several congeners that were not detected with the LLE method were quantified using the SPE method

  19. Simultaneous determination of nucleosides and their bases in Cordyceps sinensis and its substitutes by matrix solid-phase dispersion extraction and HPLC.

    Science.gov (United States)

    Wang, Zhibing; Li, Na; Wang, Min; Wang, Yue; Du, Lin; Ji, Xiaofeng; Yu, Aimin; Zhang, Hanqi; Qiu, Fangping

    2013-07-01

    Nine nucleosides and nucleobases, including uracil, adenine, thymine, uridine, adenosine, thymidine, cytidine, guanosine, and cordycepin in natural Cordyceps sinensis, cultured Cordyceps mycelia, and Cordyceps fruiting bodies were extracted by matrix solid-phase dispersion (MSPD) and determined by HPLC. The experimental conditions for the MSPD extraction were optimized. Florisil was used as dispersant, petroleum ether as washing solvent, and methanol as elution solvent. The Florisil-to-sample ratio was selected to be 4:1 and no additional clean-up sorbent was needed. The calibration curves had good linear relationships (r > 0.9997). The LOD and LOQ were in the range of 12?79 and 41?265 ng/mL, respectively. The intra- and interday precision were lower than 8.3%. The recoveries were between 61.5 and 93.2%. The present method consumed less sample compared with ultrasonic extraction and heating reflux extraction (HRE). The extraction yields obtained by using the present method are much higher than those obtained by UE and comparable to those obtained by HRE. PMID:23677705

  20. Determination of residual volatile organic compounds migrated from polystyrene food packaging into food simulant by headspace solid phase micro extraction-gas chromatography

    International Nuclear Information System (INIS)

    The residual styrene and other volatile organic compounds (VOCs) present in the polystyrene food packaging are of concern as these compounds have the potential to migrate into the food in contact. This work describes a method for quantitative determination of VOCs, namely styrene, toluene, ethyl benzene, iso-propylbenzene and n-propylbenzene that have migrated from polystyrene food packaging into food stimulant by gas chromatography-flame ionization detection (GC-FID). Headspace solid phase micro extraction (HS-SPME) technique was applied for migration test using water as food stimulant. The effects of extraction variables including sample volume, eluotropic strength, extraction temperature, extraction time, desorption time, sample agitation, and salt addition on the amounts of the extracted analyses were studied to obtain the optimal HS-SPME conditions. The optimized method was applied to test the VOCs migrated from polystyrene bowls and cups at storage temperatures ranging from 24 to 80 degree Celsius for 30 min. Styrene and ethyl benzene were found to migrate from the samples into the food stimulant. The migration of analyze was found to be strongly dependent upon the storage temperature. The HS-SPME is useful as an alternative method to determine the migration of VOCs from food packaging material into food stimulant. (author)

  1. Carboxylated graphene oxide/polyvinyl chloride as solid-phase extraction sorbent combined with ion chromatography for the determination of sulfonamides in cosmetics.

    Science.gov (United States)

    Zhong, Zhixiong; Li, Gongke; Luo, Zhibin; Liu, Zhe; Shao, Yijuan; He, Wanwen; Deng, Jianchao; Luo, Xingling

    2015-08-12

    A carboxylated graphene oxide/polyvinyl chloride (CGO/PVC) material was prepared as a sorbent for the selective extraction of sulphonamides from complex sample. After being dispersed in buffer solution, sample was transferred into the prefabricated solid-phase extraction (SPE) column, which integrated extraction and cleanup into one single-step. A multi-response optimization based on the Box-Behnken design was used to optimize factors affecting extraction efficiency. Compared with the commonly commercial sorbents including MCX, WCX and C18, CGO/PVC hybrid material had higher extraction selectivity and capacity to sulphonamides. The limits of detection and quantification for seven target compounds were in the range of 3.4-7.1 ?g/L and 11.4-23.7 ?g/L, respectively. The self-assembly SPE cartridge was successfully used to enrich seven analytes in anti-acne cosmetics prior to ion chromatography detection with good recoveries of 87.8-102.0% and relative standard deviations of 1.2-6.4%, implying that this method was suitable for routine analysis of cosmetics. PMID:26320961

  2. Method development for determination of herbicides and insecticides in surface waters using solid-phase extraction and high performance liquid chromatography

    International Nuclear Information System (INIS)

    Determination of low concentrations of pesticides in surface and ground waters requires high sensitivity analytical techniques. Solid-Phase Extraction (SPE) has been successfully employed to pre concentrate and extract pesticides compounds from water samples. High Performance Liquid Chromatography (HPLC) coupled with UV/Vis detector was used to separate and quantify the extracted compounds. In this work, samples of surface waters with known concentrations of herbicides (atrazine, simazine and trifluralin) and insecticides (aldicarb, carbofuran and carbaryl) were extracted by using SPE off-line technique. The compounds were separated and quantified by reverse phase HPLC with UV detection at 220 ?m. The extraction efficiency was compared between two columns filled with different materials: C18-bonded silica phase (500 mg) and copolymer styrenedivynilbenzene resin (250 mg). The results were evaluated as the percent recovery of compounds obtained using different solvents at different concentrations. The results showed that recovery of the analytes greater than 80 % were obtained in SPE columns filled with C18 bonded silica phase with 6 mL of acetonitrile. Once the optimum conditions were chosen for simulate water samples, the method was validated through analytical and statistical procedures and applied for surface waters. The suitability of the method was verified for the studied compounds showing good sensitivity, i. e., concentrations within the range of 0.4 to 4.0 ?gL-1 of pesticides could be quantified attending the limits proposed by official regulations. (author)

  3. Determination of etoricoxib in human plasma using automated on-line solid-phase extraction coupled with LC-APCI/MS/MS

    Directory of Open Access Journals (Sweden)

    Sérgio Luiz Dalmora

    2008-01-01

    Full Text Available A liquid chromatography-tandem mass spectrometry method with atmospheric pressure chemical ionization (LC-APCI/MS/MS was validated for the determination of etoricoxib in human plasma using antipyrin as internal standard, followed by on-line solid-phase extraction. The method was performed on a Luna C18 column and the mobile phase consisted of acetonitrile:water (95:5, v/v/ammonium acetate (pH 4.0; 10 mM, run at a flow rate of 0.6 mL/min. The method was linear in the range of 1-5000 ng/mL (r²>0.99. The lower limit of quantitation was 1 ng/mL. The recoveries were within 93.72-96.18%. Moreover, method validation demonstrated acceptable results for the precision, accuracy and stability studies.

  4. Determination of As(III), As(V), MMA and DMA in drinking water by solid phase extraction and neutron activation

    International Nuclear Information System (INIS)

    A combination of solid phase extraction, coprecipitation, and neutron activation techniques has been used to develop a speciation analysis method based on green chemistry for the major arsenic species in drinking water. Arsenate as As(V), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) are separated and preconcentrated by strongly anion and cation exchange columns in tandem while As(III) remains in the effluent. These species are then selectively eluted and As(III) coprecipitated with bismuth sulphide. This simple method has been applied to the analysis of water reference materials with good results. The detection limits are 0.9, 1.7, 1.6, 3.8 and 16 ng mL-1 for As(III), As(V), MMA, DMA and total arsenic, respectively, using a neutron flux of 2.5 x 1011 cm-2 s-1 at the Dalhousie University SLOWPOKE-2 reactor (DUSR) facility and anti-coincidence gamma-ray spectrometry. (author)

  5. Utilizing thin-film solid-phase extraction to assess the effect of organic carbon amendments on the bioavailability of DDT and dieldrin to earthworms

    Science.gov (United States)

    Andrade, Natasha A.; Centofanti, Tiziana; McConnell, Laura L.; Hapeman, Cathleen J.; Torrents, Alba; Anh, Nguyen; Beyer, W. Nelson; Chaney, Rufus L.; Novak, Jeffrey M.; Anderson, Marya O.; Cantrell, Keri B.

    2014-01-01

    Improved approaches are needed to assess bioavailability of hydrophobic organic compounds in contaminated soils. Performance of thin-film solid-phase extraction (TF-SPE) using vials coated with ethylene vinyl acetate was compared to earthworm bioassay (Lumbricus terrestris). A DDT and dieldrin contaminated soil was amended with four organic carbon materials to assess the change in bioavailability. Addition of organic carbon significantly lowered bioavailability for all compounds except for 4,4?-DDT. Equilibrium concentrations of compounds in the polymer were correlated with uptake by earthworms after 48d exposure (R2 = 0.97; p 40yr of aging. Results show that TF-SPE can be useful in examining potential risks associated with contaminated soils and to test effectiveness of remediation efforts.

  6. Determination of quinolone residues in infant and young children powdered milk combining solid-phase extraction and ultra-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Herrera-Herrera, Antonio V; Hernández-Borges, Javier; Rodríguez-Delgado, Miguel A; Herrero, Miguel; Cifuentes, Alejandro

    2011-10-21

    The present work describes a method based on solid-phase extraction (SPE) and ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) for the simultaneous determination of three quinolones (pipemidic acid, oxolinic acid and flumequine) and twelve fluoroquinolones (marbofloxacin, fleroxacin, pefloxacin, levofloxacin, norfloxacin, ciprofloxacin, enrofloxacin, danofloxacin, lomefloxacin, difloxacin, sarafloxacin, and moxifloxacin) in different infant and young children powdered milks. After suitable deproteination of the reconstituted powdered samples, a SPE procedure was developed providing recovery values higher than 84% (RSDs lower than 13%) for all the analytes, with limits of detection between 0.04 and 0.52 ?g/kg. UPLC-MS/MS analyses were carried out in less than 10 min. Sixteen infant and young children powdered milk samples of different origin, type and composition bought at Spanish markets were analyzed. Residues of the selected antibiotics were not detected in any of the analyzed samples. PMID:21683365

  7. Novel solid phase extraction procedure for gold(III) on Dowex M 4195 prior to its flame atomic absorption spectrometric determination

    International Nuclear Information System (INIS)

    A method for solid phase extraction (SPE) of gold(III) using Dowex M 4195 chelating resin has been developed. The optimum experimental conditions for the quantitative sorption of gold(III), pH, effect of flow rates, eluent types, sorption capacity and the effect of diverse ions on the sorption of gold(III) have been investigated. The chelating resin can be reused for more than 100 cycles of sorption-desorption without any significant change in sorption of gold(III) ions. The recovery values for gold(III) and detection limit (LOD) of gold were greater than 95% and 1.61 ?g L-1, respectively. The preconcentration factor was 31. The relative standard deviation of the method was -1. The proposed method has been applied for the determination of gold(III) in some real samples including water, soil and sediment samples

  8. Magnetic Fe3O4-C nanoparticles modified with 1-(2-thiazolylazo)-2-naphthol as a novel solid-phase extraction sorbent for preconcentration of copper (II)

    International Nuclear Information System (INIS)

    We report on a new magnetic nanosorbent for solid phase extraction of Cu(II) before its determination by flame atomic absorption spectrometry. The magnetic sorbent is composed of carbon-coated magnetite nanoparticles (Fe3O4-C) synthesized by a single-step solvothermal reaction and then loaded with the chelator 1-(2-thiazolylazo)-2-naphthol. It was used for the preconcentration of Cu(II) ions from water and food samples. The effects of pH value and volume of sample, of type and volume of eluent, and of interfering ions were investigated. Under the optimum conditions, the calibration graph is linear in the 4.0–400 ?g L?1 concentration range, with a detection limit of 1.5 ?g L?1. The method was validated by using a certified reference material (NIST 1566b; oyster tissue) and applied to the determination of trace copper in spiked water and food samples. (author)

  9. Bacillus sp. immobilized on Amberlite XAD-4 resin as a biosorbent for solid phase extraction of thorium prior to UV-vis spectrometry determination

    International Nuclear Information System (INIS)

    A method has been developed for the preconcentration of Th prior to its determination by UV-vis spectrophotometry after complexation with Arsenazo III. A column was packed with Amberlite Xa-4 resin containing immobilized Bacillus sp. as a solid phase extractant. Parameters such as ph of the solution and sample, the concentration of Th, the volume and type of eluent, flow rate and effect of matrix interference were studied. The optimum ph for the sorption of Th is 5. 0, and quantitative evaluation occurs with 1 mol L-1 HCl. The tolerance limits of some electrolytes were also studied. The loading capacity was determined to be 17. 2 mg g-1. The method was applied to the determination of Th in real ore sample and validated by analyzing a certified reference samples (Ncs Dc-73350; poplar leaves). (author)

  10. Trapping the Pasture Odorscape Using Open-Air Solid-Phase Micro Extraction, a Tool to Assess Grassland Value

    Science.gov (United States)

    Cornu, Agnès; Farruggia, Anne; Leppik, Ene; Pinier, Centina; Fournier, Florence; Genoud, David; Frérot, Brigitte

    2015-01-01

    Besides supporting cattle feeding, grasslands are home to a diversity of plants and insects that interact with each other by emitting volatile compounds. The aim of this work was to develop a method to determine permanent grassland odorscape and relate it to flower-visiting insects. Two grasslands were chosen for their contrasting levels of botanical diversity, resulting from differing grazing managements. Measurements were made over two periods of three consecutive days at the beginning of grazing, and just after the cows had left the plots. Volatile compounds were trapped using solid-phase microextraction (SPME) fibers exposed eight hours a day in three exclosures per plot, and then analyzed by gas-chromatography-mass spectrometry (GC-MS). Insects were trapped using pan traps and a net, sorted and counted. The open air SPME method yielded volatile compound profiles that were richer than maize field profiles, comprising the common green leaf volatiles (GLV) and more specific ones. Differences between the odorscapes of the two grasslands were found, but they were not as marked as expected from their botanical composition. By contrast, there were sharp differences between the two periods, resulting from the combined effects of changes in weather conditions, plant phenological stage and grazing progress. Several correlations between insect counts and volatile compounds were found. Although their correlation coefficients were low, some of them were confirmed when tested by Spearman rank correlation, and could be logically explained. This method of grassland odorscape deserves to be developed because it can provide information on many aspects of grassland function and on the stresses that grassland plants undergo. PMID:26536369

  11. Comparison between a commercial solid-phase extraction cartridge and a home-made silver containing charcoal column: purification of Mo-99 from I-131 and Te-121

    International Nuclear Information System (INIS)

    Among the radioisotopes used for medical application in Nuclear Medicine, 99mTc, readily available from the elution of 99Mo/99mTc generators, is the most used, responsible for more than eighty percent of the total applications. These generators use the 99Mo radioisotope that is produced in nuclear reactors and IPEN imports all the 99Mo used in Brazil, mainly from Canada (Nordion). Due to the increasing needs of the Nuclear Medicine in Brazil and the world shortage of 99Mo observed since 2008, IPEN decided to construct a new research reactor named Brazilian Multipurpose Reactor (BMR) as well as to develop the production of 99Mo through the route of 235U fission using a CINTICHEM modified separation process. The 99Mo obtained from this process contains some contaminants and need to be purified. The aim of this work is to compare the preliminary results of the purification step of the solution containing 99Mo and the contaminants, 131I and 121Te in the silver containing charcoal column and a solid-phase extraction cartridge. The purification process of 99Mo coming from fission LEU foils was performed by adsorption chromatography using a home-made activated charcoal containing silver column (AC-Ag) and a commercial solid-phase extraction cartridge (OnGuard II Ag). High yields of 99Mo elution and high retention of 131I were achieved in the AC-Ag column and silver cartridge but 121Te was more retained in the cartridge than in the AC-Ag column. (author)

  12. Ultraviolet vapor generation atomic fluorescence spectrometric determination of mercury in natural water with enrichment by on-line solid phase extraction

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Deyuan [Beijing Titan Instruments Co., Ltd., Beijing 100015 (China); Gao, Feng; Zhang, Zhaohui [Beijing Entry–Exit Inspection and Quarantine Bureau, Beijing 100026 (China); Zhao, Liqian [Beijing Titan Instruments Co., Ltd., Beijing 100015 (China); Liu, Jixin, E-mail: ljx2117@gmail.com [Beijing Titan Instruments Co., Ltd., Beijing 100015 (China); Ye, Jianping; Li, Junwei; Zheng, Fengxi [Beijing Titan Instruments Co., Ltd., Beijing 100015 (China)

    2013-10-01

    A novel method, which coupled an on-line solid phase extraction (SPE) enrichment with ultraviolet vapor generation (UVG) atomic fluorescence spectrometry (AFS), was developed to improve the sensitivity of mercury determination and to remove the interference of some anion and organics to UVG of mercury. A high mercury retention efficiency and maximum exclusion of inorganic and organic matrix in water samples were achieved by using C{sub 18} SPE mini cartridge modified with sodium diethyldithiocarbamate (DDTC). Fast and efficient elution from the cartridge was found by using L-cysteine mixing solution. Furthermore, through the investigation of different UV reactor designs, the most important factor was the structure of the reactor (which corresponded roughly to the photon flux) wherein the tubing was sintered into the UV lamp to give the highest UV generation efficiency. The second factor was the materials of the tubing (which roughly corresponded to the working wavelength). Synthetic quartz, characterized by the highest transparency at 185 nm, attained the highest UVG efficiency, suggesting that the most favorable wavelength for UVG was 185 nm. Under optimum conditions, the achievable detection limit (3?) with sample loadings of 10.0 mL was 0.03 ng L{sup ?1} and 0.08 ng L{sup ?1} with different manifolds, respectively. The method was successfully applied to the determination of Hg in tap water, river water and lake water samples. - Graphical abstract: An interference free ultraviolet vapor generation based method was applied to determine ultratrace mercury in water sample. - Highlights: • Hg was enriched by on-line solid phase extraction. • Hg was detected by ultraviolet vapor generation AFS. • The interference of some anion and some organics was removed. • The effects of details of UV set were systemically discussed.

  13. [Simultaneous determination of 23-antibiotics in mariculture water using solid-phase extraction and high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Du, Juan; Zhao, Hongxia; Chen, Jingwen

    2015-04-01

    A method for the determination of 23 antibiotics from 6 categories in water was developed by using solid-phase extraction and high performance liquid chromatography-tandem mass spectrometry (SPE-HPLC-MS/MS). Water samples were enriched and cleaned-up by solid-phase extraction cartridges. The MS detection parameters of the analyzed antibiotics, the pH values of loading buffers and the volumes of the eluents were optimized by comparing the sample recoveries under different conditions. All antibiotics were separated by gradient elution with the mobile phases of 0.1% (v/v) formic acid and 1 g/L ammonium formate in water and aceto-nitrile-methanol (1:1, v/v) mixture. The eluate was then analyzed by HPLC-MS/MS in both positive and negative electrospray ionization conditions with multiple reaction monitoring (MRM) mode. The method detection limits (MDLs) were in the range of 0.1-2.9 ng/L and the recoveries of 23 antibiotics in water ranged from 47.3% to 132.6%. The developed method was applied to the analysis of 5 water samples from mariculture ponds located in Dongying City, Shandong Province. The results showed that the antibiotics could be detected in all water samples. The trimethoprim showed the highest detection rate, and the florfenicol had the highest mass concentration which reached 261. 0 ng/L. The results showed that the developed method is efficient, sensitive and reliable, which is suitable for the detection of antibiotics in seawater samples. PMID:26292403

  14. Ultraviolet vapor generation atomic fluorescence spectrometric determination of mercury in natural water with enrichment by on-line solid phase extraction

    International Nuclear Information System (INIS)

    A novel method, which coupled an on-line solid phase extraction (SPE) enrichment with ultraviolet vapor generation (UVG) atomic fluorescence spectrometry (AFS), was developed to improve the sensitivity of mercury determination and to remove the interference of some anion and organics to UVG of mercury. A high mercury retention efficiency and maximum exclusion of inorganic and organic matrix in water samples were achieved by using C18 SPE mini cartridge modified with sodium diethyldithiocarbamate (DDTC). Fast and efficient elution from the cartridge was found by using L-cysteine mixing solution. Furthermore, through the investigation of different UV reactor designs, the most important factor was the structure of the reactor (which corresponded roughly to the photon flux) wherein the tubing was sintered into the UV lamp to give the highest UV generation efficiency. The second factor was the materials of the tubing (which roughly corresponded to the working wavelength). Synthetic quartz, characterized by the highest transparency at 185 nm, attained the highest UVG efficiency, suggesting that the most favorable wavelength for UVG was 185 nm. Under optimum conditions, the achievable detection limit (3?) with sample loadings of 10.0 mL was 0.03 ng L?1 and 0.08 ng L?1 with different manifolds, respectively. The method was successfully applied to the determination of Hg in tap water, river water and lake water samples. - Graphical abstract: An interference free ultraviolet vapor generation based method was applied to determine ultratrace mercury in water sample. - Highlights: • Hg was enriched by on-line solid phase extraction. • Hg was detected by ultraviolet vapor generation AFS. • The interference of some anion and some organics was removed. • The effects of details of UV set were systemically discussed

  15. Efficient tandem solid-phase extraction and liquid chromatography-triple quadrupole mass spectrometry method to determine polar benzotriazole, benzothiazole and benzenesulfonamide contaminants in environmental water samples.

    Science.gov (United States)

    Herrero, P; Borrull, F; Pocurull, E; Marcé, R M

    2013-09-27

    An analytical method has been developed that allows the simultaneous determination of five benzotriazole (BTRs), four benzothiazole (BTs) and five benzenesulfonamide (BSAs) derivates. The method is based on tandem solid-phase extraction (SPE) with Oasis HLB followed by a clean-up step with Florisil. The chromatographic analysis was performed in less than 15min and detection was carried out with a triple quadrupole mass analyser operating in multiple reaction monitoring (MRM) mode. A comparison was performed between Oasis HLB and Oasis MAX sorbents for the solid-phase extraction, with Oasis HLB being the sorbent that gave the highest recoveries, ranging between 75% and 106%, depending on the compound and the matrix analysed. The proposed clean-up with Florisil sorbent reduced the matrix effect to below 20%. The repeatability (%RSD, 50-3000ng/L, n=3) of the method was less than 15% for all of the compounds in all of the matrices. The limits of detection (LODs) achieved ranged from 1ng/L for BTR in river water up to 100ng/L for BT in influent sewage. All of the compounds were determined in environmental waters such as river water and sewage. The highest concentrations determined corresponded to influent sewage samples in which the sum of concentrations for all compounds were between 4.6?g/L and 8.0?g/L. These concentrations were slightly reduced in secondary effluent and tertiary effluent sewage. Moreover, samples from tertiary effluent sewage based on ultra-filtration membrane treatments were also analysed and preliminary results seem to indicate that these treatments may be most effective for removing BTR, BT and BSA derivates. PMID:23972459

  16. Trace analysis of endocrine disrupting compounds in environmental water samples by use of solid-phase extraction and gas chromatography with mass spectrometry detection.

    Science.gov (United States)

    Azzouz, Abdelmonaim; Ballesteros, Evaristo

    2014-09-19

    A novel analytical method using a continuous solid-phase extraction system in combination with gas chromatography-mass spectrometry for the simultaneous separation and determination of endocrine disrupting compounds (EDCs) is reported. The method was applied to major EDCs of various types including parabens, alkylphenols, phenylphenols, bisphenol A and triclosan in water. Samples were preconcentrated by using an automatic solid-phase extraction module containing a sorbent column, and retained analytes eluted with acetonitrile for derivatization with a mixture of N,O-bis(trimethylsilyl)trifluoroacetamide and trimethylchlorosilane. A number of variables potentially influencing recovery of the target compounds such as the type of SPE sorbent (Silica gel, Florisil, RP-C18, Amberlite XAD-2 and XAD-4, Oasis HLB and LiChrolut EN), eluent and properties of the water including pH and ionic strength, were examined. LiChrolut EN was found to be the most efficient sorbent for retaining the analytes, with ?100% efficiency. The ensuing method was validated with good analytical results including low limits of detection (0.01-0.08ng/L for 100mL of sample) and good linearity (r(2)>0.997) throughout the studied concentration ranges. The method exhibited good accuracy (recoveries of 90-101%) and precision (relative standard deviations less than 7%) in the determination of EDCs in drinking, river, pond, well, swimming pool and waste water. Waste water samples were found to contain the largest number and highest concentrations of analytes (3.2-390ng/L). PMID:25129389

  17. Determination of the hydrophobic fraction of Ca, Fe, Mg and Zn in dark color honeys using solid phase extraction and flame atomic absorption spectrometry

    Scientific Electronic Library Online (English)

    Pawel, Pohl; Helena, Stecka; Krzysztof, Greda; Piotr, Jamroz.

    2012-06-01

    Full Text Available Neste estudo, avaliou-se a fração hidrofóbica de Ca, Fe, Mg e Zn em méis escuros por meio de extração em fase sólida utilizando material à base de sílica gel com grupos ativos fenil ligados monomericamente. Verificou-se que Fe está associado com esta fração, provavelmente compostos polifenólicos, no [...] mais alto grau. A contribuição da fração hidrofóbica no conteúdo total deste elemento nos méis analisados representou 7-43%. A confiabilidade destes resultados foi verificada através de extração em fase sólida utilizando material à base de sílica gel com grupos ativos octadecil ligados polimericamente (SupercleanÔ ENVI DSC-18). Além disso, estabeleceu-se uma forte correlação positiva entre a concentração de Fe na fração hidrofóbica avaliada e a densidade óptica dos méis escuros, indicando uma possível contribuição dos complexos azuis deste metal com substâncias fenólicas para a cor global do mel. Abstract in english In this study, the hydrophobic fraction of Ca, Fe, Mg and Zn in dark honeys was assessed by means of solid phase extraction using silica gel based material with monomerically bonded phenyl active groups (Discovery® DSC-Ph tubes). It was found that Fe is associated with this fraction, likely polyphen [...] olic compounds, to the highest degree. The contribution of the hydrophobic fraction to the total content of this element in analyzed honeys accounted for 7-43%. The reliability of these results was verified using for solid phase extraction silica gel based material with polymerically bonded octadecyl active groups (SupercleanÔ ENVI DSC-18). Additionally, a strong positive correlation was established between the concentration of Fe in the hydrophobic fraction assessed and the optical density of dark honeys, indicating a possible contribution of blue complexes of this metal with phenolic substances to the overall color of honey.

  18. Salicylic acid functionalized silica-coated magnetite nanoparticles for solid phase extraction and preconcentration of some heavy metal ions from various real samples

    Directory of Open Access Journals (Sweden)

    Afkhami Abbas

    2011-07-01

    Full Text Available Abstract A method for the preconcentration of trace heavy metal ions in environmental samples has been reported. The presented method is based on the sorption of Cu(II, Cd(II, Ni(II and Cr(III ions with salicylic acid as respective chelate on silica-coated magnetite nanoparticles. Prepared adsorbent was characterized by XRD, SEM, BET and FT-IR measurements. The metals content of the sorbed complexes are eluted using 4.0 mL of 1.0 mol L-1 nitric acid. The influences of the analytical parameters including pH, amount of solid phase and condition of eluting solution, the effects of matrix ions on the retention of the analytes were examined. The accuracy and precision of suggested method were tested by analyzing of certified reference materials. The detection limits (3Sb/m, N = 8 for Cu(II, Cd(II, Ni(II and Cr(III ions are 0.22, 0.11, 0.27 and 0.15 ?g L-1, respectively, and the maximum preconcentration factor is 200. The method was successfully applied to the evaluation of these trace and toxic metals in various waters, foods and other samples.

  19. Solid-phase extraction of copper, iron and zinc ions on Bacillus thuringiensis israelensis loaded on Dowex optipore V-493

    Energy Technology Data Exchange (ETDEWEB)

    Tuzen, Mustafa; Melek, Esra [Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250 Tokat (Turkey); Soylak, Mustafa [Erciyes University, Faculty of Science and Arts, Chemistry Department, 38039 Kayseri (Turkey)], E-mail: msoylak@gmail.com

    2008-11-30

    Bacillus thuringiensis israelensis loaded on Dowex optipore V-493 as new adsorbent for the separation-preconcentration of heavy metal ions has been proposed. The analytical conditions for the quantitative recoveries of copper(II), iron(III) and zinc(II) including pH, amounts of adsorbent, sample volume, etc. were investigated. The influences of alkaline and earth alkaline ions were also reported. The recovery values for the analytes are generally higher than 95%. The preconcentration factor was 37. The limit of detections of the analyte ions (k = 3, N = 21) were 1.14 {mu}g L{sup -1} for copper, 2.01 {mu}g L{sup -1} for iron and 0.14 {mu}g L{sup -1} for zinc. The relative standard deviations of the determinations were found to be lower than 9%. The procedure was validated by analyzing copper, iron and zinc contents in two certified reference materials, NRCC-SLRS-4 Riverine water and NIST SRM 1515 Apple leaves. Agreements between the obtained results and the certified values were achieved. The developed preconcentration method was applied in the flame atomic absorption spectrometric determination of copper, iron and zinc in several samples including a multivitamin-multimineral tablet, dialysis solutions, natural waters and some food samples.

  20. Solid-phase extraction of copper, iron and zinc ions on Bacillus thuringiensis israelensis loaded on Dowex optipore V-493

    International Nuclear Information System (INIS)

    Bacillus thuringiensis israelensis loaded on Dowex optipore V-493 as new adsorbent for the separation-preconcentration of heavy metal ions has been proposed. The analytical conditions for the quantitative recoveries of copper(II), iron(III) and zinc(II) including pH, amounts of adsorbent, sample volume, etc. were investigated. The influences of alkaline and earth alkaline ions were also reported. The recovery values for the analytes are generally higher than 95%. The preconcentration factor was 37. The limit of detections of the analyte ions (k = 3, N = 21) were 1.14 ?g L-1 for copper, 2.01 ?g L-1 for iron and 0.14 ?g L-1 for zinc. The relative standard deviations of the determinations were found to be lower than 9%. The procedure was validated by analyzing copper, iron and zinc contents in two certified reference materials, NRCC-SLRS-4 Riverine water and NIST SRM 1515 Apple leaves. Agreements between the obtained results and the certified values were achieved. The developed preconcentration method was applied in the flame atomic absorption spectrometric determination of copper, iron and zinc in several samples including a multivitamin-multimineral tablet, dialysis solutions, natural waters and some food samples

  1. Sistema limpo em linha para extração em fase sólida de contaminantes emergentes em águas naturais An in-line clean system for the solid-phase extraction of emerging contaminants in natural waters

    Directory of Open Access Journals (Sweden)

    Fernando F. Sodré

    2010-01-01

    Full Text Available A solid-phase in-line extraction system for water samples containing low levels of emerging contaminants is described. The system was specially developed for large volume samples (up to 4 L using commercial solid-phase extraction (SPE cartridges. Four sets containing PTFE-made connectors, brass adapters and ball valves were used to fit SPE cartridges and sample bottles to a 4-port manifold attached to a 20 L carboy. A lab-made vacuum device was connected to the manifold cap. The apparatus is robust and less expensive than the typical available system. Its also provides less experimental handling, avoiding cross contamination and sample losses.

  2. Sistema limpo em linha para extração em fase sólida de contaminantes emergentes em águas naturais An in-line clean system for the solid-phase extraction of emerging contaminants in natural waters

    OpenAIRE

    Fernando F. Sodré; Marco Antonio F. Locatelli; Wilson F. Jardim

    2010-01-01

    A solid-phase in-line extraction system for water samples containing low levels of emerging contaminants is described. The system was specially developed for large volume samples (up to 4 L) using commercial solid-phase extraction (SPE) cartridges. Four sets containing PTFE-made connectors, brass adapters and ball valves were used to fit SPE cartridges and sample bottles to a 4-port manifold attached to a 20 L carboy. A lab-made vacuum device was connected to the manifold cap. The apparatus i...

  3. Trace-chitosan-wrapped multi-walled carbon nanotubes as a new sorbent in dispersive micro solid-phase extraction to determine phenolic compounds.

    Science.gov (United States)

    Cao, Wan; Hu, Shuai-Shuai; Ye, Li-Hong; Cao, Jun; Xu, Jing-Jing; Pang, Xiao-Qing

    2015-04-17

    This report describes the use of trace-chitosan-wrapped multi-walled carbon nanotubes (CS-MWCNTs) as a sorbent material in dispersive micro solid-phase extraction (DMSPE), which was combined with ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry to analyze phenolic compounds in chrysanthemum tea and a chrysanthemum beverage. In this study, for the first time, CS-MWCNTs were used as a sorbent for this microextraction mode. Moreover, the proposed method exhibits the advantages of simplicity, rapidity, small sample amount and ease of operation. Furthermore, all of the important parameters that affect the extraction efficiency, such as the sorbent, pH, extraction time and type of elution solvent, were investigated and optimized in the DMSPE. Under the optimized extraction condition, the limit of detection, which was calculated based on a signal-to-noise ratio of 3, was 0.22-16.19ngmL(-1). Satisfactory recovery values of 89-106% were obtained for the tested samples. The results show that the developed method was successfully applied to determine the content of chlorogenic acid and flavonoids in complex chrysanthemum samples. PMID:25748543

  4. Ampholine-functionalized hybrid organic-inorganic silica material as sorbent for solid-phase extraction of acidic and basic compounds.

    Science.gov (United States)

    Wang, Tingting; Chen, Yihui; Ma, Junfeng; Chen, Mingliang; Nie, Chenggang; Hu, Minjie; Li, Ying; Jia, Zhijian; Fang, Jianghua; Gao, Haoqi

    2013-09-20

    A novel sorbent for solid-phase extraction (SPE) was synthesized by chemical immobilization of ampholine on hybrid organic-inorganic silica material. The ampholine-functionalized hybrid organic-inorganic silica sorbent is consisted of aliphatic amine groups, carboxyl groups and long carbon chains, allowing for extraction of both acidic and basic compounds. The retention properties of the developed sorbent were evaluated for 1-hydroxy-2-naphthoic acid (HNA), 1-naphthoic acid (NA), 3-hydroxybenzoic acid (HBA), benzoic acid (BA), sorbic acid (SA), vanillic aldehyde (VA), butyl 4-hydroxybenzoate (BHB), propyl 4-hydroxybenzoate (PHB), ethyl 4-hydroxybenzoate (EHB), and methyl 4-hydroxybenzoate (MHB). The results show that such a sorbent has three types of interaction, i.e., electrostatic interaction, hydrophobic interaction, and hydrogen bonding, exhibiting high extraction efficiency towards the compounds tested. The adsorption capacities of the analytes ranged from 0.61 to 6.54?gmg(-1). The reproducibility of the sorbent preparation was evaluated at three spiking concentration levels, with relative standard deviations (RSDs) of 1.0-10.5%. The recoveries of ten acidic and basic compounds spiked in beverage Coca-Cola(®) sample ranged from 82.5% to 98.2% with RSDs less than 5.8%. Under optimum conditions, the ampholine-functionalized hybrid organic-inorganic silica sorbent rendered higher extraction efficiency for acidic compounds than that of the commercially available ampholine-functionalized silica particles, and was comparable to that of the commercial Oasis WAX and Oasis WCX. PMID:23953713

  5. A cadmium(II)-based metal-organic framework material for the dispersive solid-phase extraction of polybrominated diphenyl ethers in environmental water samples.

    Science.gov (United States)

    Su, Hao; Wang, Ze; Jia, Yuqian; Deng, Liulin; Chen, Xiangfeng; Zhao, Rusong; Chan, T-W Dominic

    2015-11-27

    In this study, a stable cadmium(II)-based metal-organic framework (MOF) material was designed and used as a sorbent for the dispersive solid-phase extraction (dSPE) of polybrominated diphenyl ethers (PBDEs) in environmental water samples. Gas chromatography coupled with triple quadrupole mass spectrometer (GC-MS/MS), working in the negative chemical ionization mode, was used to quantify the target analytes. Characterization of the material was performed by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), elementary analyses (EA) and thermogravimetric analyses (TGA). The synthesized rod shape MOF is on the micro level in size and has excellent chemical and solvent stability. The extraction conditions, including the extraction time, temperature and ionic strength, were examined systematically using response surface methodology (RSM). Under optimized conditions, the method that was developed showed an excellent extraction performance. Good linearity (R(2)>0.99) within the concentration range of 0.25-250ngL(-1) was obtained. Low limits of detection (0.08-0.15ngL(-1), signal-to-noise ratio=3:1) and good precision (relative standard deviation <12%, n=6) were achieved. The developed method was applied to analyze natural and spiked environmental water samples. PMID:26522746

  6. Solid-phase extraction followed by dispersive liquid-liquid microextraction for the sensitive determination of ecstasy compounds and amphetamines in biological samples

    Directory of Open Access Journals (Sweden)

    H. A. Mashayekhi

    2014-09-01

    Full Text Available A novel approach for the determination of ecstasy and amphetamines (3,4-methylenedioxymethylamphetamine (MDMA, Ecstasy, 3,4-methylenedioxyamphetamine (MDA, 3,4-methylenedioxyethylamphetamine (MDEA and 3,4-methylenedioxypropylamphetamine (MDPA in biological samples is presented. The analytes were extracted from the matrix and transferred to a small volume of a high density, water insoluble solvent using solid-phase extraction (SPE followed by dispersive liquid-liquid microextraction (DLLME. This combination not only resulted in a high enrichment factor, but also it could be used in complex matrices (biological samples. Some important extraction parameters, such as sample solution flow rate, sample pH, type and volume of extraction and disperser solvents as well as the salt addition, were studied and optimized. Under the optimized conditions, the calibration graphs were linear in the range of 0.5-500 µg L-1 and 1.0-500 µg L-1 with detection limits in the range of 0.1-0.3 µg L-1 and 0.2-0.7 µg L-1 in urine and plasma samples, respectively. The results showed that SPE-DLLME is a suitable method for the determination of ecstasy components and amphetamines in biological and water samples. DOI: http://dx.doi.org/10.4314/bcse.v28i3.3

  7. Solid-Phase Extraction Followed by Dispersive Liquid-Liquid Microextraction Based on Solidification of Floating Organic Drop for the Determination of Parabens.

    Science.gov (United States)

    Hashemi, Beshare; Shamsipur, Mojtaba; Fattahi, Nazir

    2015-09-01

    A dispersive liquid-liquid microextraction based on solidification of floating organic drop method combined with solid-phase extraction (500-mg C18 sorbent) was developed for preconcentration and determination of some parabens. The experimental parameters influencing the extraction efficiency such as the type of extraction and disperser solvents, as well as their volumes, breakthrough volume, flow rate and salt addition were studied and optimized. The optimum experimental conditions found included: sample volume, 100 mL; KCl concentration, 1% (w/v); extraction solvent (1-undecanol) volume, 20 µL and disperser solvent (acetone) volume, 250 µL. Under the optimum experimental conditions, calibration graphs were linear in the range of 1-200 µg L(-1) with limits of detection ranged from 0.3 to 1.7 µg L(-1). The relative standard deviations were in the range of 1.2-3.1% (n = 5). The enrichment factors and absolute recoveries of parabens in different matrices were 245-1886 and 9.0-69.8%, respectively. The method was applied to the simultaneous determination of parabens in different matrices. The relative recoveries from water, shampoo and mouth rinse samples, which have been spiked at different levels of parabens, were 87.83-112.25%, 82.80-108.40% and 90.10-97.60%, respectively. PMID:25716984

  8. Development and validation of an HPLC-method for determination of free and bound phenolic acids in cereals after solid-phase extraction.

    Science.gov (United States)

    Irakli, Maria N; Samanidou, Victoria F; Biliaderis, Costas G; Papadoyannis, Ioannis N

    2012-10-01

    Whole cereal grains are a good source of phenolic acids associated with reduced risk of chronic diseases. This paper reports the development and validation of a high-performance liquid chromatography-diode array detection (HPLC-DAD) method for the determination of phenolic acids in cereals in either free or bound form. Extraction of free phenolic acids and clean-up was performed by an optimised solid-phase extraction (SPE) protocol on Oasis HLB cartridges using aqueous methanol as eluant. The mean recovery of analytes ranged between 84% and 106%. Bound phenolic acids were extracted using alkaline hydrolysis with mean recoveries of 80-95%, except for gallic acid, caffeic acid and protocatechuic acid. Both free and bound phenolic extracts were separated on a Nucleosil 100 C18 column, 5 ?m (250 mm × 4.6 mm) thermostated at 30 °C, using a linear gradient elution system consisting of 1% (v/v) acetic acid in methanol. Method validation was performed by means of linearity, accuracy, intra-day and inter-day precision and sensitivity. Detection limits ranged between 0.13 and 0.18 ?g/g. The method was applied to the analysis of free and bound phenolic acids contents in durum wheat, bread wheat, barley, oat, rice, rye, corn and triticale. PMID:25005991

  9. Solid-phase spectrophotometry

    International Nuclear Information System (INIS)

    The results of developing the method of solid-phase spectrophotometry for the last 6 years are reviewed and trends in its development are indicated. Special emphasis is laid on the measurement techniques of light absorption by solid phase and on basic, including the novel ones, procedures of sample preparation. Analytical characteristics of the above method used for the determination of Be, Cd, Mo, Nb, Ru, Th, U, Zr, etc, are presented. 54 refs., 2 figs., 2 tabs

  10. Use of activated charcoal in a solid-phase extraction technique for analysis of pesticide residues in tomatoes

    OpenAIRE

    Kaipper Beatriz I. A.; Madureira Luiz A. S.; Corseuil Henry X.

    2001-01-01

    The present work describes extraction and purification methods that were developed to determine and to monitor the content of organophosphorus pesticides in tomato crops from the agricultural district of Florianópolis, Brazil. SPE technique with activated charcoal was used for purification and recovery of the pesticides methamidophos, acephate, malation and methyl parathion. The solvents used for sample extraction and elution were chosen after several comparative tests. Best results were achi...

  11. A nanoparticle-based solid-phase extraction procedure followed by spectrofluorimetry to determine carbaryl in different water samples

    Energy Technology Data Exchange (ETDEWEB)

    Tabrizi, Ahad Bavili, E-mail: a.bavili@tbzmed.ac.ir, E-mail: abavilitabrizia@gmail.com [Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Rashidi, Mohammad Reza [Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz, (Iran, Islamic Republic of); Ostadi, Hadi [Department of Chemistry, Payam-e-noor University, Ardabil Branch, Ardabil (Iran, Islamic Republic of)

    2014-04-15

    In this study, a new method based on Fe{sub 3}O{sub 4} magnetite nanoparticles (MNPs) has been developed for the extraction, preconcentration and determination of trace amounts of carbaryl from environmental water samples. Fe{sub 3}O{sub 4} MNPs were synthesized and modified by the surfactant sodium dodecyl sulfate (SDS), then successfully applied for the extraction of carbaryl and its determination by spectrofluorimetry. Main factors affecting the adsolubilization of carbaryl such as the amount of SDS, pH value, standing time, desorption solvent and maximal extraction volume were optimized. Under the selected conditions, carbaryl could be quantitatively extracted. Acceptable recoveries (84.5-91.9%) and relative standard deviations (6.2%) were achieved in analyzing spiked water samples. A concentration factor of 20 was achieved by the extraction of 100 mL of environmental water samples. The limit of detection and quantification were found to be 2.1 and 6.9 ?g L{sup -1}, respectively. The proposed method was successfully applied for the extraction and determination of carbaryl in environmental water samples. (author)

  12. Is Solid Phase Microextraction (SPME) an appropriate method for extraction of volatile oxidation products from complex food systems.

    DEFF Research Database (Denmark)

    Jacobsen, Charlotte; Horn, Anna Frisenfeldt

    Volatile secondary lipid oxidation products can be identified and quantified by GC-FID or GC-MS. An extraction step is, however, needed before GC analysis. A range of different extraction methods are available such as static headspace, dynamic headspace and SPME. Each of these methods has its advantages and drawbacks. Among the advantages of the SPME method are its high sensitivity compared to static headspace and that it is less laborious than the dynamic headspace method. For these reasons, the use of SPME has increased in both academia and industry during the last decade. The extraction efficiency obtained with the SPME method can be affected by different factors such as fiber type, stirring of sample versus not stirring, extraction temperature and time. These factors can easily be controlled and optimized to obtain the highest possible extraction efficiency. However, extraction efficiency can also be affected by uncontrollable factors such as batch to batch variation between fibers of the same type and presence of compounds in the sample matrix, which competes with the compounds of interest for adsorption to the SPME fiber. The latter factor is particularly a problem when SPME is used for analysis of lipid oxidation during storage of complex food matrices. Examples on how uncontrollable factors have affected results obtained with the SPME method in the authors’ lab will be given and the appropriateness of the SPME method for the analysis of volatile oxidation products in selected food systems will be discussed.

  13. Solid phase microextraction (SPME) for extraction of volatile oxidation products from complex food systems – Pros and cons

    DEFF Research Database (Denmark)

    Jacobsen, Charlotte; Horn, Anna Frisenfeldt

    Volatile secondary lipid oxidation products can be identified and quantified by GC-FID or GC-MS. An extraction step is, however, needed before GC analysis. A range of different extraction methods are available such as static headspace, dynamic headspace and SPME. Each of these methods has its advantages and drawbacks. Among the advantages of the SPME method are its high sensitivity compared to static headspace and that it is less laborious than the dynamic headspace method. For these reasons, the use of SPME has increased in both academia and industry during the last decade. The extraction efficiency obtained with the SPME method can be affected by different factors such as fiber type, stirring of sample versus not stirring, extraction temperature and time. These factors can easily be controlled and optimized to obtain the highest possible extraction efficiency. However, extraction efficiency can also be affected by uncontrollable factors such as batch to batch variation between fibers of the same type and presence of compounds in the sample matrix, which competes with the compounds of interest for adsorption to the SPME fiber. The latter factor is particularly a problem when SPME is used for analysis of lipid oxidation during storage of complex food matrices. Examples on how uncontrollable factors have affected results obtained with the SPME method in the authors’ lab will be given and the appropriateness of the SPME method for the analysis of volatile oxidation products in selected food systems will be discussed.

  14. A nanoparticle-based solid-phase extraction procedure followed by spectrofluorimetry to determine carbaryl in different water samples

    International Nuclear Information System (INIS)

    In this study, a new method based on Fe3O4 magnetite nanoparticles (MNPs) has been developed for the extraction, preconcentration and determination of trace amounts of carbaryl from environmental water samples. Fe3O4 MNPs were synthesized and modified by the surfactant sodium dodecyl sulfate (SDS), then successfully applied for the extraction of carbaryl and its determination by spectrofluorimetry. Main factors affecting the adsolubilization of carbaryl such as the amount of SDS, pH value, standing time, desorption solvent and maximal extraction volume were optimized. Under the selected conditions, carbaryl could be quantitatively extracted. Acceptable recoveries (84.5-91.9%) and relative standard deviations (6.2%) were achieved in analyzing spiked water samples. A concentration factor of 20 was achieved by the extraction of 100 mL of environmental water samples. The limit of detection and quantification were found to be 2.1 and 6.9 ?g L-1, respectively. The proposed method was successfully applied for the extraction and determination of carbaryl in environmental water samples. (author)

  15. Simultaneous determination of metabolites of trimethylbenzenes, dimethylbenzylmercapturicacid and dimethylhippuric acid, in human urine by solid-phase extraction followed by liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Moriwaki, Hiroshi; Watanabe, Ayumi; Arakawa, Ryuichi; Tsujimoto, Yuji; Shimizu, Mitsuru; Noda, Tsutomu; Warashina, Munehiro; Tanaka, Masanobu

    2002-11-01

    We describe a novel method for the determination of three kinds of dimethylbenzylmercapturic acids (DMM) and six kinds of dimethylhippuric acids (DMH), found in urine as metabolites of trimethylbenzenes, based on liquid chromatography/electrospray ionization tandem mass spectrometry. A solid-phase extraction procedure was used for the extractions of DMM and DMH from a urine sample, and the separation was performed on a reversed-phase C(30) column. The analytes were ionized by electrospray in the positive-ion mode. Operating in the multiple reaction monitoring mode, the linearity of the relative mass spectrometric responses to the internal standard versus analyte concentrations were established in the range 0.1-100 ng ml(-1). The extraction procedure was rapid and the relative standard deviations were below 5%. The detection limits of DMM and DMH in the urine by the proposed method were in the ranges 0.26-0.41 and 0.42-2.0 ng l(-1), respectively. Furthermore, DMM and DMH were detected in a urine sample from an individual who did not suffer from occupational exposure to trimethylbenzenes, by using this method. PMID:12447892

  16. Surface modified magnetic Fe{sub 3}O{sub 4} nanoparticles as a selective sorbent for solid phase extraction of uranyl ions from water samples

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi, Susan, E-mail: ssadeghi@birjand.ac.ir [Department of Chemistry, Faculty of Science, University of Birjand, P.O. Box. 97175/615, Birjand (Iran, Islamic Republic of); Azhdari, Hoda [Department of Chemistry, Faculty of Science, University of Birjand, P.O. Box. 97175/615, Birjand (Iran, Islamic Republic of); Arabi, Hadi [Magnetism and Superconducting Research Lab, Department of Physics, Faculty of Science, University of Birjand, P.O. Box. 97175/615, Birjand (Iran, Islamic Republic of); Moghaddam, Ali Zeraatkar [Department of Chemistry, Faculty of Science, University of Birjand, P.O. Box. 97175/615, Birjand (Iran, Islamic Republic of)

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer A new sorbent based on functionalized magnetite nanoparticles with quercetin is reported. Black-Right-Pointing-Pointer The quercetin based magnetic nanoparticles could be used as a sorbent to remove toxic uranyl ions from water samples. Black-Right-Pointing-Pointer The sorbent provides a rapidly and easy separation of uranyl ions only by using a permanent magnet. Black-Right-Pointing-Pointer This technique is considered more efficient separation compared to conventional filtering or centrifuging methods for the removing of the sorbent. - Abstract: In this study, silica-coated magnetic nanoparticles modified with quercetin were synthesized by a sol-gel method. These magnetic nanoparticles were assessed as a new solid phase sorbent for extraction of uranyl ions from aqueous solutions. The crystal and chemical structures and magnetic property of the new sorbent were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectrophotometer (FT-IR), and vibration sample magnetometer (VSM). The experimental parameters affecting the extraction efficiency of uranyl ions from aqueous solutions using the synthesized sorbent were optimized by means of the response surface methodology. The adsorption equilibrium of uranyl ions onto the sorbent was explained by Langmuir isotherm and maximum monolayer adsorption capacity was found 12.33 mg/g. The synthesized sorbent was applied to extraction of uranyl ions from different water samples.

  17. Determination of validamycin A in agricultural food samples by solid-phase extraction combined with liquid chromatography-atmospheric pressure chemical ionisation-tandem mass spectrometry.

    Science.gov (United States)

    Wang, Chuanxian; Zhang, Zhigang; Shen, Yan; Tian, Zhengan; Xu, Dunming; Han, Chao

    2015-02-15

    For the first time, a rapid, sensitive and accurate liquid chromatography-atmospheric pressure chemical ionisation-tandem mass spectrometry (LC-APCI-MS/MS) method was developed for determination of validamycin A in agricultural food samples (rice, agaric, almond, cabbage, green onion, carrot, tomato, cucumber and spinach). The validamycin A residue was extracted with methanol-water (9/1, v/v) or methanol by vortex, and a HLB solid-phase extraction cartridge was used for cleaning up the extracts. LC-APCI-MS/MS data acquisition was carried out in multiple reaction monitoring (MRM) mode. A series of matrix-matched calibration solutions ranging from 2.5 to 50ngmL(-1) were used to record calibration curve. The limit of quantification (LOQ) was 10?gkg(-1). The average recoveries, measured at three concentrations levels (10.0, 50.0, 100.0?gkg(-1)) were in the range 83.5-109.6%. The proposed method offers the best sensitivity and specificity for the routine analysis of validamycin A in agricultural food samples. PMID:25236210

  18. Determination of polybrominated diphenyl ethers and polychlorinated biphenyls in fishery and aquaculture products using sequential solid phase extraction and large volume injection gas chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Lu, Dasheng; Lin, Yuanjie; Feng, Chao; Wang, Dongli; Qiu, Xinlei; Jin, Yu'e; Xiong, Libei; Jin, Ying; Wang, Guoquan

    2014-01-15

    A new method was developed to determine polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in fishery and aquaculture products. Samples were extracted by an accelerated solvent extraction system and cleaned up by sequential solid phase extraction (SPE) including dispersive SPE (D-SPE) and tandem SPE. PBDEs and PCBs were analyzed by a large-volume injection gas chromatography triple quadrupole mass spectrometry (LVI-GC-QqQ-MS/MS). Good linearity (R(2)?0.9958) was achieved. Method detection limits (MDLs) were 0.16-3.3pgg(-1) (wet weight, ww) for PBDEs and 0.13-0.97pgg(-1)ww for PCBs. Mean recoveries were 60-140% with relative standard deviations (RSDs) of less than 20% in weever fish, scallop and shrimp samples spiked at a lower level of 13-31pgg(-1)ww and a higher level of 50-125pgg(-1)ww. Certified reference materials were analyzed with acceptable results. The method reduced solvent consumption, analytical time and labor, and is suitable for the routine analysis of PBDEs and PCBs in fishery and aquaculture products. PMID:24321764

  19. Trace monitoring of silver ions in food and water samples by flame atomic absorption spectrophotometry after preconcentration with solvent-assisted dispersive solid phase extraction.

    Science.gov (United States)

    Omidi, Fariborz; Behbahani, Mohammad; Shahtaheri, Seyed Jamaleddin; Salimi, Sara

    2015-06-01

    In this research, a new sample treatment technique termed solvent-assisted dispersive solid phase extraction (SADSPE) was developed. The new method was based on the dispersion of the sorbent into the sample to maximize the contact surface. In this approach, the dispersion of the sorbent at a very low milligram level was achieved by injecting a mixture solution of the sorbent and disperser solvent into the aqueous sample. Thereby, a cloudy solution formed. The cloudy solution resulted from the dispersion of the fine particles of the sorbent in the bulk aqueous sample. After extraction, the cloudy solution was centrifuged and the enriched analytes in the sediment phase dissolved in ethanol and determined by FAAS. Under the optimized conditions, the detection limit for silver ions was 0.8 ?g L(-1). The relative standard deviations for six separate extraction experiments for determination of 5 and 200 ?g L(-1) of silver ions was 3.4 and 3.1 %. The preconcentration factor was found to be 61.7. SADSPE was successfully applied for trace determination of silver ions in water and food samples. PMID:25980728

  20. Simultaneous Determination of 10 Adulterants in Antihypertensive Functional Foods Using Multi-Walled Carbon Nanotubes-Dispersive Solid-Phase Extraction Coupled with High Performance Liquid Chromatography.

    Science.gov (United States)

    Zeng, Li; Li, Yongxin; Wu, Xin; Zhang, Jing; Xie, Juan; Sun, Chengjun

    2015-10-01

    Consumption of functional foods based on extracts from selected herbs to alleviate hypertension is an increasingly common practice in China. Adulteration of these foods with pharmaceuticals can significantly impact a consumer's health. To control the quality of the functional foods effectively, a method for the simultaneous determination of 10 common adulterants including chlortalidone, hydrochlorothiazide, indapamide, metoprolol, nifedipine, nimodipine, nitrendipine, reserpine, triamterene and valsartan in antihypertensive functional foods was developed. The target chemicals in samples were ultrasonically extracted with acetonitrile, and then cleaned-up with multi-walled carbon natotubes-dispersive solid-phase extraction. Finally, the analytes were separated with a C18 column using binary mobile phases consisting of acetonitrile and 0.03 mol/L KH2PO4 solutions (pH 3.0). The flow rate of the mobile phase was 0.80 mL/min, and the column temperature was 35°C. The detection wavelength was set at 220 nm. The limits of detection and quantification of the method ranged from 0.014 to 0.053 and 0.047 to 0.178 ?g/mL, respectively. The recoveries of the method were in the range of 80.1-98.1% with relative standard deviations <9.53%. The method was successfully applied to the determination of the target chemicals in real samples and simulated samples, and respirine was detected in one tonic wine sample with a concentration of 56.8 ± 1.2 mg/L. PMID:25840433

  1. 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

    International Nuclear Information System (INIS)

    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 %. (author)

  2. Application of solid-phase extraction coupled with freezing-lipid filtration clean-up for the determination of endocrine-disrupting phenols in fish

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Yun Gyong [Hazardous Substance Research Team, Korea Basic Science Institute, Seoul 136-701 (Korea, Republic of); Department of Civil Environment Engineering, Korea University, Seoul 136-701 (Korea, Republic of); Shin, Jeoung Hwa; Kim, Hye-Young [Hazardous Substance Research Team, Korea Basic Science Institute, Seoul 136-701 (Korea, Republic of); Khim, Jeehyeong [Department of Civil Environment Engineering, Korea University, Seoul 136-701 (Korea, Republic of); Lee, Mi-Kyoung [College of Pharmacy, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Hong, Jongki [College of Pharmacy, Kyung Hee University, Seoul 130-701 (Korea, Republic of)], E-mail: jhong@khu.ac.kr

    2007-11-05

    An analytical method has been developed for the determination of endocrine-disrupting phenols (eight alkylphenols and bisphenol A) in fish samples. The extraction of nine phenols from fish samples was carried out by ultrasonification. After the extraction, high levels of lipids were removed by freezing-lipid filtration instead of the traditional methods of column chromatography or saponification. During freezing-lipid filtration, about 90% of the lipids were eliminated without any significant loss of phenolic compounds. For further purification, hydrophilic-lipophilic balanced copolymer (HLB) sorbent with a poly(divinylbenzene-co-N-vinylpyrrolidone) phase and Florisil-solid-phase extraction (SPE) cartridges were used to eliminate the remaining interferences. Silyl-derivatization, with N,N'-methyl-(tert-butyldimethylsilyl) trifluoroacetamide (MTBSTFA), was applied to enhance the sensitivity of detection of phenolic compounds. Quantification was performed by gas chromatography/mass spectrometry (GC/MS)-selected ion monitoring (SIM) mode, using deuterium-labeled internal standards. Spiking experiments were carried out to determine the recovery, precision and detection limit of the method. The overall recoveries ranged between 70 and 120%, with relative standard deviations of 3-17% for the entire procedure. The detection limits of the method for the nine phenols ranged from 0.02 to 0.41 ng g{sup -1}. The method provided simultaneous screening and accurate confirmation of each phenol when applied to biological samples.

  3. Application of solid-phase extraction coupled with freezing-lipid filtration clean-up for the determination of endocrine-disrupting phenols in fish

    International Nuclear Information System (INIS)

    An analytical method has been developed for the determination of endocrine-disrupting phenols (eight alkylphenols and bisphenol A) in fish samples. The extraction of nine phenols from fish samples was carried out by ultrasonification. After the extraction, high levels of lipids were removed by freezing-lipid filtration instead of the traditional methods of column chromatography or saponification. During freezing-lipid filtration, about 90% of the lipids were eliminated without any significant loss of phenolic compounds. For further purification, hydrophilic-lipophilic balanced copolymer (HLB) sorbent with a poly(divinylbenzene-co-N-vinylpyrrolidone) phase and Florisil-solid-phase extraction (SPE) cartridges were used to eliminate the remaining interferences. Silyl-derivatization, with N,N'-methyl-(tert-butyldimethylsilyl) trifluoroacetamide (MTBSTFA), was applied to enhance the sensitivity of detection of phenolic compounds. Quantification was performed by gas chromatography/mass spectrometry (GC/MS)-selected ion monitoring (SIM) mode, using deuterium-labeled internal standards. Spiking experiments were carried out to determine the recovery, precision and detection limit of the method. The overall recoveries ranged between 70 and 120%, with relative standard deviations of 3-17% for the entire procedure. The detection limits of the method for the nine phenols ranged from 0.02 to 0.41 ng g-1. The method provided simultaneous screening and accurate confirmation of each phenol when applied to biological samples

  4. Simultaneous Determination of Perfluorinated Compounds in Edible Oil by Gel-Permeation Chromatography Combined with Dispersive Solid-Phase Extraction and Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Yang, Lili; Jin, Fen; Zhang, Peng; Zhang, Yanxin; Wang, Jian; Shao, Hua; Jin, Maojun; Wang, Shanshan; Zheng, Lufei; Wang, Jing

    2015-09-30

    A simple analytical method was developed for the simultaneous analysis of 18 perfluorinated compounds (PFCs) in edible oil. The target compounds were extracted by acetonitrile, purified by gel permeation chromatography (GPC) and dispersive solid-phase extraction (DSPE) using graphitized carbon black (GCB) and octadecyl (C18), and analyzed by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ES-MS/MS) in negative ion mode. Recovery studies were performed at three fortification levels. The average recoveries of all target PFCs ranged from 60 to 129%, with an acceptable relative standard deviation (RSD) (1-20%, n = 3). The method detection limits (MDLs) ranged from 0.004 to 0.4 ?g/kg, which was significantly improved compared with the existing liquid-liquid extraction and cleanup method. The method was successfully applied for the analysis of all target PFCs in edible oil samples collected from markets in Beijing, China, and the results revealed that C6-C10 perfluorocarboxylic acid (PFCAs) and C7 perfluorosulfonic acid PFSAs were the major PFCs detected in oil samples. PMID:26357966

  5. Simultaneous determination of fifteen low-dosed benzodiazepines in human urine by solid-phase extraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Borrey, D; Meyer, E; Lambert, W; Van Peteghem, C; De Leenheer, A P

    2001-12-25

    A gas chromatographic-mass spectrometric method was developed for the simultaneous analysis of 15 low-dosed benzodiazepines, both parent compounds and their corresponding metabolites, in human urine. The target compounds are alprazolam, alpha-hydroxyalprazolam, 4-hydroxyalprazolam, flunitrazepam, 7-aminoflunitrazepam, desmethylflunitrazepam, flurazepam, hydroxyethylflurazepam, nitrogen-desalkylflurazepam, ketazolam, oxazepam, lormetazepam, lorazepam, triazolam and alpha-hydroxytriazolam. Nitrogen-methylclonazepam is used as the internal standard. The urine sample preparation involves enzymatic hydrolysis of the conjugated metabolites with Helix pomatia beta-glucuronidase for 1 h at 56 degrees C followed by solid-phase extraction on a phenyl-type column. The extracted benzodiazepines are subsequently analyzed on a polydimethylsiloxane column using on-column injection to enhance sensitivity. The extraction efficiency exceeded 80% for all compounds except for oxazepam, lorazepam and 4-hydroxyalprazolam which had recoveries of about 60%. The LODs ranged from 13 to 30 ng/ml in the scan mode and from 1.0 to 1.7 ng/ml in the selected ion monitoring (SIM) mode. Linear calibration curves were obtained in the concentration ranges from 50 to 1000 ng/ml in the scan mode and from 5 to 100 ng/ml in the SIM mode. The within-day and day-to-day relative standard deviations at three different concentrations never exceeded 15%. PMID:11767312

  6. Simultaneous determination of phenolic acids and flavonoids in rice using solid-phase extraction and RP-HPLC with photodiode array detection.

    Science.gov (United States)

    Irakli, Maria N; Samanidou, Victoria F; Biliaderis, Costas G; Papadoyannis, Ioannis N

    2012-07-01

    An analytical method based on an optimized solid-phase extraction procedure and followed by high-performance liquid chromatography (HPLC) separation with diode array detection was developed and validated for the simultaneous determination of phenolic acids (gallic, protocatechuic, 4-hydroxy-benzoic, vanillic, caffeic, syringic, p-coumaric, ferulic, sinapic, and cinnamic acids), flavanols (catechin and epicatechin), flavonols (myricetin, quercetin, kaempferol, quercetin-3-O-glucoside, hyperoside, and rutin), flavones (luteolin and apigenin) and flavanones (naringenin and hesperidin) in rice flour (Oryza sativa L.). Chromatographic separation was carried out on a PerfectSil Target ODS-3 (250 mm × 4.6 mm, 3 ?m) column at temperature 25°C using a mobile phase, consisting of 0.5% (v/v) acetic acid in water, methanol, and acetonitrile at a flow rate 1 mL min(-1) , under gradient elution conditions. Application of optimum extraction conditions, elaborated on both Lichrolut C(18) and Oasis HLB cartridges, have led to extraction of phenolic acids and flavonoids from rice flour with mean recoveries 84.3-113.0%. The developed method was validated in terms of linearity, accuracy, precision, stability, and sensitivity. Repeatability (n = 5) and inter-day precision (n = 4) revealed relative standard deviation (RSD) <13%. The optimized method was successfully applied to the analysis of phenolic acids and flavonoids in pigmented (red and black rice) and non-pigmented rice (brown rice) samples. PMID:22761138

  7. Ultrasound-assisted magnetic solid-phase extraction for the determination of some transition metals in Orujo spirit samples by capillary electrophoresis.

    Science.gov (United States)

    Peña Crecente, Rosa M; Lovera, Carlha Gutiérrez; García, Julia Barciela; Latorre, Carlos Herrero; Martín, Sagrario García

    2016-01-01

    Ultrasound-assisted magnetic solid-phase extraction coupled to capillary electrophoresis was optimized for the preconcentration and determination of Zn(II), Cu(II), Mn(II) and Cd(II) as their complexes with 1,10-phenanthroline (Phen). Both pre- and on-capillary complexations were employed to obtain stable metal-Phen complexes. The parameters that have an influence on the electrophoretic separation and the MSPE process were studied and optimized using different experimental designs. Metals were extracted from 10 mL of sample at pH 5 using 3mg of magnetic particles functionalized with carboxylic groups. The metals were eluted as metal-Phen complexes and analyzed by capillary electrophoresis. The method showed low limits of detection for metals 0.49-2.19 ?g L(-1), and high preconcentration factors, 39-44, The efficiencies of the extraction method were in the range 77.1-87.5% and the precision (RSD < 10%) and accuracy were between 98.2% and 101.6%. The method was applied to the determination of the aforementioned metals in Galician Orujo spirit samples. PMID:26212969

  8. Polypyrrole/magnetic nanoparticles composite as an efficient sorbent for dispersive micro-solid-phase extraction of antidepressant drugs from biological fluids.

    Science.gov (United States)

    Asgharinezhad, Ali Akbar; Karami, Sara; Ebrahimzadeh, Homeira; Shekari, Nafiseh; Jalilian, Niloofar

    2015-10-15

    In this study, polypyrrole/magnetic nanoparticles composites in the presence of two different dopants were synthesized with the aid of chemical oxidative polymerization process for dispersive-?-solid phase extraction (D-?-SPE). The synthesized magnetic sorbents were characterized by various techniques. The results exhibited that the nanocomposite modified by polypyrrole with sodium perchlorate as a dopant demonstrated higher extraction efficiency for citalopram (CIT) and sertraline (STR) as the model compounds. This nanosorbent in combination with high performance liquid chromatography-UV detection was applied for extraction, preconcentration and determination of CIT and STR in urine and plasma samples. The effect of various parameters on the extraction efficiency including: sample pH, amount of sorbent, sorption time, eluent and its volume, salt content, and elution time were investigated and optimized. The opted conditions were: sample pH, 9.0; sorbent dosage, 10mg; sorption time, 7min; elution solvent and its volume, 0.06molL(-1) HCl in methanol, 120?L; elution time, 2min and without addition of salt to the sample. The calibration curves were linear in the concentration range of 1-800?gL(-1). The limits of detection (LODs) were obtained in the range of 0.2-1.0?gL(-1) for CIT and 0.3-0.7?gL(-1) for STR, respectively. The percent of extraction recoveries and relative standard deviations (n=5) were in the range of 93.4-99, 4.8-8.4 for CIT and 94-98.4, 4.3-9.2 for STR, respectively. Finally, the applicability of the method was successfully confirmed by the extraction and determination of CIT and STR in human urine and plasma samples. PMID:26253373

  9. IR spectroscopic study of scandium extraction from sulfuric acid by solid-phase extractants based on tributyl phosphate, di-2-ethylhexylphosphoric acid, dibenzo-18-crown-6 and their mixtures

    International Nuclear Information System (INIS)

    Solid-phase extractants (TVEKS) containing tributyl-phosphate (I), di(2-ethylhexyl)phosphoric acid (II), dibenzo-18-crown-6 (III) and their mixtures were prepared, their use for scandium extraction from sulfuric acid solutions with 6 mol/l concentration was studied. By the method of IR spectroscopy it was ascertained that during scandium extraction by TVEKS-III Sc3+ ions are integrated into microcycle cavity, forming a host-guest type complex. Mechanism of scandium extraction by TVEKS-I can be described as hydrate-solvate one: [I · H3O]x+[Sc(SO4)y]·zHSO4-. IR spectroscopy data suggest cation exchange mechanism of scandium extraction by TVEKS-II. In TVEKS-(III+II) and TVEKS-(III+I) interaction between crown other and organophosphoric compound takes place giving rise to antisynergetic effect during metal ion extraction

  10. Use of activated charcoal in a solid-phase extraction technique for analysis of pesticide residues in tomatoes

    Directory of Open Access Journals (Sweden)

    Kaipper Beatriz I. A.

    2001-01-01

    Full Text Available The present work describes extraction and purification methods that were developed to determine and to monitor the content of organophosphorus pesticides in tomato crops from the agricultural district of Florianópolis, Brazil. SPE technique with activated charcoal was used for purification and recovery of the pesticides methamidophos, acephate, malation and methyl parathion. The solvents used for sample extraction and elution were chosen after several comparative tests. Best results were achieved using ethyl acetate for extraction and dichloromethane - ethyl acetate (7:3 for elution. Average recoveries from the matrices fortified with 0.20 to 0.60 mug g-1 ranged from 85.2 to 100 % with overall coefficients of variation of 1.3 to 6.3 %. The limits of detection of the method varied between 0.04 and 0.12 ng g-1. Activated charcoal demonstrated to be efficient for tomato matrix purification and for quantitative recovery of the analytes.

  11. Headspace Sorptive Extraction (HSSE), Stir Bar Sorptive Extraction (SBSE) and Solid Phase Micro-Extraction (SPME) applied to the analysis of roasted Arabica coffee and coffee brew

    OpenAIRE

    Bicchi, Carlo; RUBIOLO, Patrizia

    2002-01-01

    Headspace sorptive extraction (HSSE) and stir bar sorptive extraction (SBSE), two recently introduced solventless enrichment techniques, have been applied to the analysis of the headspace of Arabica roasted coffee and of the headspace of the brew and of the brew itself. In both HSSE and SBSE enrichment is performed on a thick film of poly(dimethylsiloxane) (PDMS) coated onto a magnet incorporated in a glass jacket. Sampling is done by placing the PDMS stir bar in the headspace (gas phase extr...

  12. A multi-element solid-phase extraction method for trace metals determination in environmental samples on Amberlite XAD-2000

    Energy Technology Data Exchange (ETDEWEB)

    Bulut, Volkan Numan [Department of Chemistry, Giresun Faculty of Arts and Sciences, Karadeniz Technical University, 28049 Giresun (Turkey); Gundogdu, Ali [Department of Chemistry, Faculty of Arts and Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey); Duran, Celal [Department of Chemistry, Faculty of Arts and Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey); Senturk, Hasan Basri [Department of Chemistry, Faculty of Arts and Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey); Soylak, Mustafa [Department of Chemistry, Faculty of Arts and Sciences, Erciyes University, 38039 Kayseri (Turkey)]. E-mail: msoylak@gmail.com; Elci, Latif [Department of Chemistry, Faculty of Arts and Sciences, Pamukkale University, 20020 Denizli (Turkey); Tufekci, Mehmet [Department of Chemistry, Faculty of Arts and Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey)

    2007-07-19

    A method for the preconcentration of some transition elements at trace level was proposed using a column filled with Amberlite XAD-2000 resin. Metal ions were adsorbed on XAD-2000 as their diethyldithiocarbamate chelates, then analytes retained on the resin were eluted by 1 mol L{sup -1} nitric acid in acetone and determined by flame atomic absorption spectrometry (FAAS). The influences of some analytical parameters including pH of sample solution, ligand amount, the type, concentration and volume of elution solution, flow rates of the sample and eluent solutions, adsorption capacity of the resin and sample volume on the preconcentration efficiency have been investigated. The influences of some matrix elements were also examined. The detection limit (N = 20, 3 sigma) for Mn(II), Fe(II), Co(II), Cu(II), Cd(II), Zn(II), Pb(II) and Ni(II) were found as 0.20, 0.35, 0.25, 0.20, 0.20, 0.15, 0.45 and 0.25 {mu}g L{sup -1}, respectively. The validation of the procedure was carried out by analysis of certified reference materials. The proposed method was applied to natural waters and kale vegetable (Brassica oleracea var. acephala)

  13. A multi-element solid-phase extraction method for trace metals determination in environmental samples on Amberlite XAD-2000

    International Nuclear Information System (INIS)

    A method for the preconcentration of some transition elements at trace level was proposed using a column filled with Amberlite XAD-2000 resin. Metal ions were adsorbed on XAD-2000 as their diethyldithiocarbamate chelates, then analytes retained on the resin were eluted by 1 mol L-1 nitric acid in acetone and determined by flame atomic absorption spectrometry (FAAS). The influences of some analytical parameters including pH of sample solution, ligand amount, the type, concentration and volume of elution solution, flow rates of the sample and eluent solutions, adsorption capacity of the resin and sample volume on the preconcentration efficiency have been investigated. The influences of some matrix elements were also examined. The detection limit (N = 20, 3 sigma) for Mn(II), Fe(II), Co(II), Cu(II), Cd(II), Zn(II), Pb(II) and Ni(II) were found as 0.20, 0.35, 0.25, 0.20, 0.20, 0.15, 0.45 and 0.25 ?g L-1, respectively. The validation of the procedure was carried out by analysis of certified reference materials. The proposed method was applied to natural waters and kale vegetable (Brassica oleracea var. acephala)

  14. Head Space Solid Phase Micro-Extraction (HS - SPME) of volatile organic compounds produced by Sporidiobolus salmonicolor (CBS 2636) Microextração em Fase Sólida (MEFS) de compostos voláteis produzidos por Sporidiobolus salmonicolor (CBS 2636)

    OpenAIRE

    Eunice Valduga; Alexsandra Valerio; Helen Treichel; Irajá Nascimento Filho; Agenor Fúrigo Júnior; Marco Di Luccio

    2010-01-01

    The aim of the present study was the assessment of volatile organic compounds produced by Sporidiobolus salmonicolor (CBS 2636) using methyl and ethyl ricinoleate, ricinoleic acid and castor oil as precursors. The analysis of the volatile organic compounds was carried out using Head Space Solid Phase Micro-Extraction (HS - SPME). Factorial experimental design was used for investigating extraction conditions, verifying stirring rate (0-400 rpm), temperature (25-60 ºC), extraction time (10-30 m...

  15. Speciation of As(III)/As(V) in water samples by a magnetic solid phase extraction based on Fe?O?/Mg-Al layered double hydroxide nano-hybrid followed by chemiluminescence detection.

    Science.gov (United States)

    Abdolmohammad-Zadeh, Hossein; Talleb, Zeynab

    2014-10-01

    A novel magnetic solid phase extraction method was developed for the speciation of As(III)/As(V) in aqueous solutions utilizing Fe3O4-doped Mg-Al layered double hydroxide (LDH) as a nano-sorbent. The method is based on the separation and pre-concentration of As(V) by Fe3O4/Mg-Al LDH nano-hybrid prior to determination by a chemiluminescence (CL) technique. The CL route involves the oxidation of luminol by vanadomolybdoarsenate heteropoly acid in a basic media. Since the existing cations cannot be adsorbed by positively charged layers of the LDH and other potentially interferent anions had no considerable effect on the CL reaction, it provides a very selective and sensitive determination approach for As(V). The determination of total arsenic and hence indirectly As(III) involve the pre-oxidation of As(III) to As(V) by a mixture of hydrogen peroxide and potassium hydroxide. Several factors affecting the extraction and determination of the analyte were investigated and optimized. Under optimum conditions, the calibration graph was linear in the range of 5.0-5000 ng L(-1). The limit of detection and enrichment factor was 2.0 ng L(-1) and 80, respectively. The method was validated by the analysis of a standard reference material (NIST SRM 1643e), and successfully applied to the speciation of arsenic in several water samples with recoveries in the range of 93.3-106.7% for the spiked samples. PMID:25059142

  16. Zinc oxide/polypyrrole nanocomposite as a novel solid phase microextraction coating for extraction of aliphatic hydrocarbons from water and soil samples.

    Science.gov (United States)

    Amanzadeh, Hatam; Yamini, Yadollah; Moradi, Morteza

    2015-07-16

    In this work, ZnO/PPy nanocomposite coating was fabricated on stainless steel and evaluated as a novel headspace solid phase microextraction (HS-SPME) fiber coating for extraction of ultra-trace amounts of environmental pollutants; namely, aliphatic hydrocarbons in water and soil samples. The ZnO/PPy nanocomposite were prepared by a two-step process including the electrochemical deposition of PPy on the surface of stainless steel in the first step, and the synthesis of ZnO nanorods by hydrothermal process in the pores of PPy matrix in the second step. Porous structure together with ZnO nanorods with the average diameter of 70 nm were observed on the surface by using scanning electron microscopy (SEM). The effective parameters on HS-SPME of hydrocarbons (i.e., extraction temperature, extraction time, desorption temperature, desorption time, salt concentration, and stirring rate) were investigated and optimized by one-variable-at-a-time method. Under optimized conditions (extraction temperature, 65±1°C; extraction time, 15 min; desorption temperature, 250°C; desorption time, 3 min; salt concentration, 10% w/v; and stirring rate, 1200 rpm), the limits of detection (LODs) were found in the range of 0.08-0.5 ?g L(-1), whereas the repeatability and fiber-to-fiber reproducibility were in the range 5.4-7.6% and 8.6-10.4%, respectively. Also, the accuracies obtained for the spiked n-alkanes were in the range of 85-108%; indicating the absence of matrix effects in the proposed HS-SPME method. The results obtained in this work suggest that ZnO/PPy can be promising coating materials for future applications of SPME and related sample preparation techniques. PMID:26073809

  17. Magnetic solid phase extraction of brominated flame retardants and pentachlorophenol from environmental waters with carbon doped Fe3O4 nanoparticles

    Science.gov (United States)

    Yang, Jing; Li, Jia-yuan; Qiao, Jun-qin; Cui, Shi-hai; Lian, Hong-zhen; Chen, Hong-yuan

    2014-12-01

    Carbon doped Fe3O4 nanoparticles (Fe3O4/C) prepared by a facile hydrothermal reaction of glucose with iron resource have been applied as magnetic solid-phase extraction (MSPE) sorbent, for the first time, to extract trace brominated flame retardants (BFRs) and pentachlorophenol (PCP) from environmental waters. Various MSPE parameters were optimized including amount of Fe3O4/C nanoparticles, pH of sample solution, enrichment factor of analytes and reusability of Fe3O4/C sorbent. The reliability of the MSPE method was evaluated by the recoveries of BFRs and PCP in spiked water samples. Good recoveries (80.0-110.0%) were achieved with the relative standard deviations range from 0.3% to 6.8%. In this paper, the extraction characteristics of Fe3O4/C sorbent were further elucidated. It is found that the adsorption process of Fe3O4/C to analytes predominates the MSPE efficiency. There is hybrid hydrophobic interaction and hydrogen bonding or dipole-dipole attraction between Fe3O4/C and analytes. Notably, the chemical components of carbon layer on the surface of Fe3O4 nanoparticles were identified by X-ray photoelectron spectroscopy and thermogravimetry-mass spectrometry, and in consequence the covalent bonds between Fe3O4 and the coated carbon have been observed. In addition, the straight influence of synthesis condition of Fe3O4/C nanoparticles including glucose concentration and hydrothermal reaction time on extraction performance for BFRs and PCP has been investigated. It is confirmed that the existence of organic carbon containing functional groups over Fe3O4/C sorbent is responsible for the MSPE extraction.

  18. Graphitic carbon nitrides modified hollow fiber solid phase microextraction for extraction and determination of uric acid in urine and serum coupled with gas chromatography-mass spectrometry.

    Science.gov (United States)

    Sun, Ying-Pei; Chen, Juan; Qi, Huan-Yang; Shi, Yan-Ping

    2015-11-01

    An elevated uric acid (UA) in urine or serum can affect renal function and blood pressure, which is an indicator of gout, cardiovascular and renal diseases, hypertension, etc. In this work, a new type of mixed matrix membrane (MMM), based on graphitic carbon nitrides (g-CNs) and hollow fiber (HF), was prepared and combined with solid phase microextraction (SPME) mode to determine UA in urine and serum followed by gas chromatography-mass spectrometry (GC/MS). The porous g-CNs were dispersed in ammonia, and then the exfoliated g-CNs nanosheets were held in the pores of HF by capillary forces and sonification. The prepared g-CNs modified HF (g-CNs-HF) was immersed in biofluid directly to extract UA with SPME mode and the solvent-free mode is convenient for further derivatization and analysis. To achieve the highest extraction efficiency (EF), main extraction and derivatization parameters, such as g-CNs-HF immobilizing time, sonification power and time of extraction, derivatization and desorption time, were optimized. Under the optimum extraction conditions, a favorable linearity of UA was obtained in the range 0.1-200?gmL(-1) with correlation coefficients higher than 0.9990, and the average recoveries at three spiked levels of UA in urine and serum ranged from 80.7% to 121.6%, from 84.7% to 101.1%, respectively. The obtained results demonstrated the developed g-CNs-HF-SPME is a simple, rapid, cost-effective, solvent-free method for the analysis of UA in biofluid. PMID:26444336

  19. Solid Phase Micro-extraction (SPME) with In Situ Transesterification: An Easy Method for the Detection of Non-volatile Fatty Acid Derivatives on the Insect Cuticle.

    Science.gov (United States)

    Kühbandner, Stephan; Ruther, Joachim

    2015-06-01

    Triacylglycerides (TAGs) and other non-volatile fatty acid derivatives (NFADs) occur in large amounts in the internal tissues of insects, but their presence on the insect cuticle is controversially discussed. Most studies investigating cuticular lipids of insects involve solvent extraction, which implies the risk of extracting lipids from internal tissues. Here, we present a new method that overcomes this problem. The method employs solid phase micro-extraction (SPME) to sample NFADs by rubbing the SPME fiber over the insect cuticle. Subsequently, the sampled NFADs are transesterified in situ with trimethyl sulfonium hydroxide (TMSH) into more volatile fatty acid methyl esters (FAMEs), which can be analyzed by standard GC/MS. We performed two types of control experiments to enable significant conclusions: (1) to rule out contamination of the GC/MS system with NFADs, and (2) to exclude the presence of free fatty acids on the insect cuticle, which would also furnish FAMEs after TMSH treatment, and thus might simulate the presence of NFADs. In combination with these two essential control experiments, the described SPME technique can be used to detect TAGs and/or other NFADs on the insect cuticle. We analyzed six insect species from four insect orders with our method and compared the results with conventional solvent extraction followed by ex situ transesterification. Several fatty acids typically found as constituents of TAGs were detected by the SPME method on the cuticle of all species analyzed. A comparison of the two methods revealed differences in the fatty acid compositions of the samples. Saturated fatty acids showed by trend higher relative abundances when sampled with the SPME method, while several minor FAMEs were detected only in the solvent extracts. Our study suggests that TAGs and maybe other NFADs are far more common on the insect cuticle than usually thought. PMID:26025161

  20. A nanoparticle-based solid-phase extraction procedure followed by spectrofluorimetry to determine carbaryl in different water samples

    Scientific Electronic Library Online (English)

    Ahad Bavili, Tabrizi; Mohammad Reza, Rashidi; Hadi, Ostadi.

    2014-04-01

    Full Text Available Nesse estudo, um novo método baseado em nanopartículas de magnetita Fe3O4 (MNPs) foi desenvolvido para a extração, preconcentração e determinação de traços de carbaril de amostras de água do meio ambiente. Fe3O4 MNPs foram sintetizadas e modificadas pelo surfactante dodecil sulfato de sódio (SDS) e [...] aplicadas com sucesso na extração de carbaril e na sua determinação através de espectrofluorimetria. Fatores que afetam a adsolubilização do carbaril, como quantidade de SDS, pH, tempo de espera, solvente de desorção e volume máximo de extração foram otimizados. Sob as condições selecionadas, foi possível extrair carbaril quantitativamente. Recuperações (84,5-91,9%) e desvio padrão relativo (6,2%) aceitáveis foram alcançados ao analisar amostras de água adulterada. Um fator de concentração de 20 foi obtido na extração de 100 mL de amostras de água do meio ambiente. Os limites de detecção e quantificação encontrados foram 2,1 e 6,9 µg L-¹, respectivamente. O método proposto foi aplicado com sucesso na extração e determinação de carbaril em amostras de água do meio ambiente. Abstract in english In this study, a new method based on Fe3O4 magnetite nanoparticles (MNPs) has been developed for the extraction, preconcentration and determination of trace amounts of carbaryl from environmental water samples. Fe3O4 MNPs were synthesized and modified by the surfactant sodium dodecyl sulfate (SDS), [...] then successfully applied for the extraction of carbaryl and its determination by spectrofluorimetry. Main factors affecting the adsolubilization of carbaryl such as the amount of SDS, pH value, standing time, desorption solvent and maximal extraction volume were optimized. Under the selected conditions, carbaryl could be quantitatively extracted. Acceptable recoveries (84.5-91.9%) and relative standard deviations (6.2%) were achieved in analyzing spiked water samples. A concentration factor of 20 was achieved by the extraction of 100 mL of environmental water samples. The limit of detection and quantification were found to be 2.1 and 6.9 µg L- 1, respectively. The proposed method was successfully applied for the extraction and determination of carbaryl in environmental water samples.

  1. Strontium-90 determination in air dust filter using solid phase extraction after the accident of FD-NPS

    International Nuclear Information System (INIS)

    Radioactivities of Sr-90 in air-dust filters collected in Hitachi, Kawasaki and Toyonaka were determined using solid state extraction method and low background beta-ray counting system. In Hitachi, though the Sr-90 activity concentration was decreased with time, the activity rates of Sr-90/Cs-137 kept about 10-3 order. This fact suggests that Sr-90 transportation behavior in the atmosphere is similar to that of Cs-137 during the time of sample collection. (author)

  2. New poly(styrene/divinylbenzene) based stationary phases for the solid phase extraction of pesticides and the chromatography of carbohydrates

    International Nuclear Information System (INIS)

    The introduced sorbents based on poly(styrene/divinylbenzene) are studied regarding their extraction behavior of pesticides out of water. The sorbents are prepared with different porogens like n-octanol, n-decanol, n-dodecanol and acetone. The comparison of the extraction properties of these substances shows that the use of n-octanol as a porogen leads to the best recoveries. Furthermore this sorbent is compared to a stationary phase prepared via ring opening metathesis polymerization (ROMP) and to commercially available silica-C18. It is shown that the poly(styrene/divinylbenzene) based material on average yields higher recoveries as the other materials. Only the extraction of relatively polar pesticides works better with the ROMP based sorbent. For the chromatography of carbohydrates nonporous particles with diameters of about 3 ?m were synthesized via poly(styrene/divinylbenzene) using the activated swelling method. Quaternary ammonia functional groups were introduced into the poly(styrene/divinylbenzene) particles via their nitration, reduction and quaternization. The applicability of these stationary phases for anion exchange chromatography is shown by separation of different kinds of sugars using a pulsed amperometric detection system. Monosaccharides are isocratically separated using an eluent containing sodium hydroxide, separations of disaccharides and oligosaccharides are performed using sodium acetate gradients. Linearity, detection limits and reproducibility of the system are investigated by the analysis of glucose, sucrose and fructose out of the real samples Coca Cola and apple juice. (author)

  3. Analysis of estrogens in wastewater using solid-phase extraction, QuEChERS cleanup, and liquid chromatography/ tandem mass spectrometry.

    Science.gov (United States)

    Gunatilake, Sameera R; Craver, Shelby; Kwon, Jeong-Wook; Xia, Kang; Armbrust, Kevin; Rodriguez, Jose M; Mlsna, Todd E

    2013-01-01

    We present an improved method for trace level quantification of five estrogens including estriol, estrone, 17alpha-estradiol, 17beta-estradiol, and 17alpha-ethinylestradiol in wastewaters. Our method includes sample preparation using SPE followed by a Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) cleanup step, a derivatization, and LC/MS/MS determination. Sample extraction was carried out using Oasis HLB cartridges and a dispersive solid-phase cleanup pack containing MgSO4 and primary-secondary amine and C18 sorbents. The resulting extract was derivatized with dansyl chloride. Separation was achieved on an Agilent Zorbax Extend C18, Narrow Bore RR 2.1 x 100 mm, 3.5 pm column; quantification was accomplished in the positive ion mode using multiple reaction monitoring. The cleanup method is quick, efficient, inexpensive, and requires only 200 mL of water. Reliable linearities were obtained for all calibration curves (r2 > 0.995). Matrix effects calculated were less than 12% for all analytes, and, hence, matrix matched calibration curves were not needed. The recoveries for the estrogens ranged from 81-103%, with a high repeatability (n = 3, RSD < or = 9%) and low LOQs (0.6-0.9 ng/L). The method was used to analyze effluent and influent wastewaters in Mississippi wastewater treatment plants, but it is broadly applicable for the determination of trace estrogens in any municipal wastewater samples. PMID:24645527

  4. Monitoring of gamma radiolytic degradation products of methoxychlor pesticide in water by solid phase micro-extraction using hplc and GC-MS (abstract)

    International Nuclear Information System (INIS)

    Monitoring, removal and management of toxic chemicals is an essential area of study regarding sustainable progress. Different approaches are adopted to eliminate these water born toxics from water and waste water. Among these gamma radiolytic is an emerging option. This ionization radiation generates highly reactive radicals that reacts with pollutants and hence eliminates these. A solid-phase micro-extraction (SPME) procedure has been developed for the successful preconcentration of organic pollutant irradiated water. A SPME fused-silica fiber coated with Polyacrylate was used as a probe to extract the organic pollutant after irradiation. In this reference, degradation of priority organic pollutant methoxychlor (1, 1, 1-Trichloro 2, 2-bis (p-methoxyphenyl) ethane, in water by gamma irradiation under varied experimental conditions has been investigated. The degree of gamma radiolytic degradation was monitored by HPLC-UV and GC-MS. For 4 kGy and 5 kGy gamma radiation dose at a rate of 200 kGyh/sup -1/ greater or equal to 95 % and 98 % MXC was degraded respectively. The degradation products were identified by Mass Spectrometry after comparing their MS spectras with the NIST 98 library. The major degradation occurs via dechlorination, dehydro chlorination, by the detachment of methoxyphenyl from MXC and by interaction of other radicals generated by the water radiolysis. (author)

  5. Mixed-mode solid-phase extraction followed by acetylation and gas chromatography mass spectrometry for the reliable determination of trans-resveratrol in wine samples

    Energy Technology Data Exchange (ETDEWEB)

    Montes, R.; Garcia-Lopez, M. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain); Rodriguez, I., E-mail: isaac.rodriguez@usc.es [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain); Cela, R. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain)

    2010-07-12

    This work presents an advantageous analytical procedure for the accurate determination of free trans-resveratrol in red and white wines. The proposed method involves solid-phase extraction (SPE), acetylation of the analyte in aqueous media and further determination by gas chromatography (GC) with mass spectrometry detection (MS). The use of a mixed-mode SPE sorbent provides an improvement in the selectivity of the extraction step; moreover, the presence of several intense ions in the electron impact mass spectra of its acetyl derivative guarantees the unambiguous identification of trans-resveratrol. Considering a sample intake of 10 mL, the method provides a limit of quantification (LOQ) of 0.8 ng mL{sup -1} and linear responses for concentrations up to 2.5 {mu}g mL{sup -1}, referred to wine samples. The average recovery, estimated with samples fortified at different concentrations in the above range, was 99.6% and the inter-day precision stayed below 8%. Trans-resveratrol levels in the analyzed wines varied from 3.4 to 1810 ng mL{sup -1}. Cis-resveratrol was also found in all samples. In most cases, equal or higher responses were measured for this latter form than for the trans-isomer. The reduced form of resveratrol, dihydro-resveratrol, was systematically identified in red wines.

  6. Mixed-mode solid-phase extraction followed by acetylation and gas chromatography mass spectrometry for the reliable determination of trans-resveratrol in wine samples

    International Nuclear Information System (INIS)

    This work presents an advantageous analytical procedure for the accurate determination of free trans-resveratrol in red and white wines. The proposed method involves solid-phase extraction (SPE), acetylation of the analyte in aqueous media and further determination by gas chromatography (GC) with mass spectrometry detection (MS). The use of a mixed-mode SPE sorbent provides an improvement in the selectivity of the extraction step; moreover, the presence of several intense ions in the electron impact mass spectra of its acetyl derivative guarantees the unambiguous identification of trans-resveratrol. Considering a sample intake of 10 mL, the method provides a limit of quantification (LOQ) of 0.8 ng mL-1 and linear responses for concentrations up to 2.5 ?g mL-1, referred to wine samples. The average recovery, estimated with samples fortified at different concentrations in the above range, was 99.6% and the inter-day precision stayed below 8%. Trans-resveratrol levels in the analyzed wines varied from 3.4 to 1810 ng mL-1. Cis-resveratrol was also found in all samples. In most cases, equal or higher responses were measured for this latter form than for the trans-isomer. The reduced form of resveratrol, dihydro-resveratrol, was systematically identified in red wines.

  7. Direct Zinc Determination in Brazilian Sugar Cane Spirit by Solid-Phase Extraction Using Moringa oleifera Husks in a Flow System with Detection by FAAS.

    Science.gov (United States)

    Alves, Vanessa N; Borges, Simone S O; Coelho, Nivia M M

    2011-01-01

    This paper reports a method for the determination of zinc in Brazilian sugar cane spirit, (cachaça in Portuguese), using solid-phase extraction with a flow injection analysis system and detection by FAAS. The sorbent material used was activated carbon obtained from Moringa oleifera husks. Flow and chemical variables of the proposed system were optimized through multivariate designs. The factors selected were sorbent mass, sample pH, sample flow rate, and eluent concentration. The optimum extraction conditions were obtained using a sample pH of 4.0, a sample flow rate of 6.0?mL?min(-1), 30.0?mg of sorbent mass, and 1.0?mol?L(-1) HNO(3) as the eluent at a flow rate of 4.0?mL?min(-1). The limit of detection for zinc was 1.9??g?L(-1), and the precision was below 0.82% (20.0??g?L(-1), n = 7). The analytical curve was linear from 2 to 50??g?L(-1), with a correlation coefficient of 0.9996. The method developed was successfully applied to spiked Brazilian sugar cane spirit, and accuracy was assessed through recovery tests, with results ranging from 83% to 100%. PMID:21785595

  8. Hydrophilic interaction chromatography based solid-phase extraction and MALDI TOF mass spectrometry for revealing the influence of Pseudomonas fluorescens on phospholipids in salmon fillet.

    Science.gov (United States)

    Shen, Qing; Yang, Qi; Cheung, Hon-Yeung

    2015-02-01

    Salmon is a popular food but it is easily susceptible to spoilage by contamination with microorganisms. In this study, a method using hydrophilic interaction chromatography (HILIC)-based solid-phase extraction (SPE) and matrix-assisted laser desorption and ionization time-of-flight/time-of-flight mass spectrometry was developed and applied to reveal the effect of Pseudomonas fluorescens on salmon fillet during the shelf-life period by measuring the changes in the levels of phosphatidylcholine and phosphatidylethanolamine. Fresh samples were inoculated with P. fluorescens (10(6) cfu g(-1)) for 30 s, and lipids were extracted at 0, 24, 48, and 72 h. A homemade SPE cartridge packed with HILIC sorbent (silica derivatized with 1,2-dihydroxypropane) was used for matrix cleanup prior to analysis by mass spectrometry. In total, 30 phospholipids and 16 lysophospholipids were detected and elucidated. The results revealed that the content of phospholipids decreased significantly, whereas that of lysophospholipids increased initially, followed by a gradual reduction as the cold storage time increased. The contamination by P. fluorescens negatively affected the quality of fresh salmon without obvious physical changes, but it posed a potential threat to human health. This study suggests that the well-established method could be used for detecting phospholipids in salmon fillet and perhaps other foods as well. PMID:25492091

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

    Science.gov (United States)

    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.

  10. Simultaneous analysis of chlorophenols, alkylphenols, nitrophenols and cresols in wastewater effluents, using solid phase extraction and further determination by gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Padilla-Sánchez, J A; Plaza-Bolaños, P; Romero-González, R; Barco-Bonilla, N; Martínez-Vidal, J L; Garrido-Frenich, A

    2011-10-15

    An analytical methodology has been developed for the simultaneous extraction of 13 phenolic compounds, including chlorophenols (CPs), nitrophenols (NTPs), cresols and alkylphenols (APs) in different types of wastewater (WW) effluents. A solid-phase extraction (SPE) method has been optimized prior to the determination by gas chromatography coupled to triple quadrupole tandem mass spectrometry (GC-QqQ-MS/MS). Due to the complexity of the matrix, a comparison study of matrix-matched-calibration (MMC) and standard addition calibration (SAC) was carried out for quantification purposes. The optimized procedure was validated using the SAC approach since it provided the most adequate quantification results (in terms of recovery and precision values). Recoveries were in the range 60-135% (0.5 ?g L(-1)), 70-115% (1 ?g L(-1)), and 78-120% (5 ?g L(-1)), with precision values (expressed as relative standard deviation, RSD) ? 30% (except for 2-nitrophenol) involving intra-day and inter-day precision studies. Limits of detection (LODs) and quantification (LOQs) were also evaluated, and LOQs ranged from 0.03 ?g L(-1) to 2.5 ?g L(-1). The proposed method was applied to the analysis of 8 real WW effluent samples, finding some phenolic compounds (e.g. 2-chlorophenol, 2,4,6-trichlorophenol and 4-tert-octylphenol) at concentrations higher than the established LOQs. PMID:21962659

  11. Evaluation of ultrasound-assisted in situ sorbent formation solid-phase extraction method for determination of arsenic in water, food and biological samples.

    Science.gov (United States)

    Ezoddin, Maryam; Majidi, Behrooz; Abdi, Khosrou

    2015-01-01

    A simple and rapid ultrasound-assisted in situ sorbent formation solid-phase extraction (UAISFSPE) coupled with electrothermal atomic absorption spectrometry detection (ET-AAS) was developed for preconcentration and determination of arsenic (As) in various samples. A small amount of cationic surfactant is dissolved in the aqueous sample containing As ions, which were complexed by ammonium pyrrolidinedithiocarbamate After shaking, a little volume of hexafluorophosphate (NaPF6) as an ion-pairing agent was added into the solution by a microsyringe. Due to the interaction between surfactant and ion-pairing agent, solid particles are formed. The alkyl groups of the surfactant in the solid particles strongly interact with the hydrophobic groups of analytes and become bound. Sonication aids the dispersion of the sorbent into the sample solution and mass transfer of the analyte into the sorbent, thus reducing the extraction time. The solid particles are centrifuged, and the sedimented particles can be dissolved in an appropriate solvent to recover the absorbed analyte. After separation, total arsenic (As(III) and As(V)) was determined by ET-AAS. Several experimental parameters were investigated and optimized. A detection limit of 7?ng?L(-1) with preconcentration factor of 100 and relative standard deviation for 10 replicate determinations of 0.1?µg?L(-1) As(III) were 4.5% achieved. Consequently, the method was applied to the determination of arsenic in certified reference materials, water, food and biological samples with satisfactory results. PMID:25420432

  12. Determination of phthalate esters from environmental water samples by micro-solid-phase extraction using TiO2 nanotube arrays before high-performance liquid chromatography.

    Science.gov (United States)

    Zhou, Qingxiang; Fang, Zhi; Liao, Xiangkun

    2015-07-01

    We describe a highly sensitive micro-solid-phase extraction method for the pre-concentration of six phthalate esters utilizing a TiO2 nanotube array coupled to high-performance liquid chromatography with a variable-wavelength ultraviolet visible detector. The selected phthalate esters included dimethyl phthalate, diethyl phthalate, dibutyl phthalate, butyl benzyl phthalate, bis(2-ethylhexyl)phthalate and dioctyl phthalate. The factors that would affect the enrichment, such as desorption solvent, sample pH, salting-out effect, extraction time and desorption time, were optimized. Under the optimum conditions, the linear range of the proposed method was 0.3-200 ?g/L. The limits of detection were 0.04-0.2 ?g/L (S/N = 3). The proposed method was successfully applied to the determination of six phthalate esters in water samples and satisfied spiked recoveries were achieved. These results indicated that the proposed method was appropriate for the determination of trace phthalate esters in environmental water samples. PMID:25944027

  13. Solid Phase Extraction of Inorganic Mercury Using 5-Phenylazo-8-hydroxyquinoline and Determination by Cold Vapor Atomic Fluorescence Spectroscopy in Natural Water Samples

    Science.gov (United States)

    Daye, Mirna; Halwani, Jalal; Hamzeh, Mariam

    2013-01-01

    8-Hydroxyquinoline (8-HQ) was chosen as a powerful ligand for Hg solid phase extraction. Among several chelating resins based on 8-HQ, 5-phenylazo-8-hydroxyquinoline (5Ph8HQ) is used for mercury extraction in which the adsorption dynamics were fully studied. It has been shown that Hg(II) is totally absorbed by 5Ph8HQ within the first 30 minutes of contact time with t1/2 5 minutes, following Langmuir adsorption model. At pH 4, the affinity of mercury is unchallenged by other metals except, for Cu(II), which have shown higher Kd value. With these latter characteristics, 5Ph8HQ was examined for the preconcentration of trace levels of Hg(II). The developed method showed quantitative recoveries of Hg(II) with LOD = 0.21?pg?mL?1 and RSD = 3–6% using cold vapor atomic fluorescence spectroscopy (CV-AFS) with a preconcentration factor greater than 250. PMID:24459417

  14. Liquid carry-over in an injection moulded all-polymer chip system for immiscible phase magnetic bead-based solid-phase extraction

    DEFF Research Database (Denmark)

    Kistrup, Kasper; SØrensen, Karen Skotte

    2014-01-01

    We present an all-polymer, single-use microfluidic chip system produced by injection moulding and bonded by ultrasonic welding. Both techniques are compatible with low-cost industrial mass-production. The chip is produced for magnetic bead-based solid-phase extraction facilitated by immiscible phase filtration and features passive liquid filling and magnetic bead manipulation using an external magnet. In this work, we determine the system compatibility with various surfactants. Moreover, we quantify the volume of liquid co-transported with magnetic bead clusters from Milli-Q water or a lysis-binding buffer for nucleic acid extraction (0.1 (v/v)% Triton X-100 in 5 M guanidine hydrochloride). A linear relationship was found between the liquid carry-over and mass of magnetic beads used. Interestingly, similar average carry-overs of 1.74(8) nL/µg and 1.72(14) nL/µg were found for Milli-Q water and lysis-binding buffer, respectively.

  15. Determination of phthalate esters in environmental water by magnetic Zeolitic Imidazolate Framework-8 solid-phase extraction coupled with high-performance liquid chromatography.

    Science.gov (United States)

    Liu, Xiaomei; Sun, Zhiwei; Chen, Guang; Zhang, Wanwan; Cai, Yiping; Kong, Rongmei; Wang, Xiaoyan; Suo, Yourui; You, Jinmao

    2015-08-28

    In this study, the magnetic Zeolitic Imidazolate Framework-8 (ZIF-8) microspheres were successfully synthesized and applied as an effective sorbent for preconcentration of several typical phthalate esters (PAEs) from environmental water samples. Firstly, the solvothermal treatment method was used for preparation of Fe3O4 nanoparticles. Then, mercaptoacetic acid (MAA) was served as the functionalized chemical to modify Fe3O4 nanoparticles. The Fe3O4@ZIF-8 core-shell microspheres were synthesized through coating the MAA-capped Fe3O4 nanoparticles with ZIF-8. By coupling magnetic solid-phase extraction (MSPE) with high-performance liquid chromatography (HPLC), a reliable, sensitive and cost-effective method for simultaneous determination of five main PAEs including dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), benzyl butyl phthalate (BBP), and dioctyl phthalate (DOP) was developed. Good linearity was observed in the range of 1.0-100.0?g/L. The limits of detection (S/N=3) and limits of quantification (S/N=10) were in the range of 0.08-0.24 and 0.3-0.8?g/L, respectively. The relative standard deviations were less than 5.5% and the accuracies of the method for the PAEs were in the range from 85.6% to 103.6%. Finally, the Fe3O4@ZIF-8 was successfully applied for rapid extraction of trace amounts of PAEs in environmental water samples. PMID:26228850

  16. A general screening method for doping agents in human urine by solid phase extraction and liquid chromatography/time-of-flight mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Kolmonen, Marjo [Forensic Toxicology Division, Department of Forensic Medicine, University of Helsinki (Finland) and Doping Control Laboratory, United Laboratories Ltd., Helsinki (Finland)]. E-mail: marjo.kolmonen@helsinki.fi; Leinonen, Antti [Doping Control Laboratory, United Laboratories Ltd., Helsinki (Finland); Pelander, Anna [Forensic Toxicology Division, Department of Forensic Medicine, University of Helsinki (Finland); Ojanperae, Ilkka [Forensic Toxicology Division, Department of Forensic Medicine, University of Helsinki (Finland)

    2007-02-28

    A general screening method based on solid phase extraction (SPE) and liquid chromatography/time-of-flight mass spectrometry (LC/TOFMS) was developed and investigated with 124 different doping agents, including stimulants, {beta}-blockers, narcotics, {beta}{sub 2}-adrenergic agonists, agents with anti-estrogenic activity, diuretics and cannabinoids. Mixed mode cation exchange/C8 cartridges were applied to SPE, and chromatography was based on gradient elution on a C18 column. Ionization of the analytes was achieved with electrospray ionization in the positive mode. Identification by LC/TOFMS was based on retention time, accurate mass and isotopic pattern. Validation of the method consisted of analysis of specificity, analytical recovery, limit of detection and repeatability. The minimum required performance limit (MRPL), established by World Anti-Doping Agency (WADA), was attained to 97 doping agents. The extraction recoveries varied between 33 and 98% and the median was 58%. Mass accuracy was always better than 5 ppm, corresponding to a maximum mass error of 0.7 mDa. The repeatability of the method for spiked urine samples, expressed as median of relative standard deviations (RSD%) at concentrations of MRPL and 10 times MRPL, were 14% and 9%, respectively. The suitability of the LC/TOFMS method for doping control was demonstrated with authentic urine samples.

  17. A general screening method for doping agents in human urine by solid phase extraction and liquid chromatography/time-of-flight mass spectrometry

    International Nuclear Information System (INIS)

    A general screening method based on solid phase extraction (SPE) and liquid chromatography/time-of-flight mass spectrometry (LC/TOFMS) was developed and investigated with 124 different doping agents, including stimulants, ?-blockers, narcotics, ?2-adrenergic agonists, agents with anti-estrogenic activity, diuretics and cannabinoids. Mixed mode cation exchange/C8 cartridges were applied to SPE, and chromatography was based on gradient elution on a C18 column. Ionization of the analytes was achieved with electrospray ionization in the positive mode. Identification by LC/TOFMS was based on retention time, accurate mass and isotopic pattern. Validation of the method consisted of analysis of specificity, analytical recovery, limit of detection and repeatability. The minimum required performance limit (MRPL), established by World Anti-Doping Agency (WADA), was attained to 97 doping agents. The extraction recoveries varied between 33 and 98% and the median was 58%. Mass accuracy was always better than 5 ppm, corresponding to a maximum mass error of 0.7 mDa. The repeatability of the method for spiked urine samples, expressed as median of relative standard deviations (RSD%) at concentrations of MRPL and 10 times MRPL, were 14% and 9%, respectively. The suitability of the LC/TOFMS method for doping control was demonstrated with authentic urine samples

  18. Determination of melamine in milk and dairy products by microchip-based high-field asymmetric ion mobility spectrometry combined with solid-phase extraction.

    Science.gov (United States)

    Zhao, Wei-jun; Wang, Yonghuan; Li, Juan; Li, Ling-feng; Wang, Qi; Han, Ke; Zhang, Yuang; Li, Xin; Li, Peng; Luo, Jikui; Wang, Xiaozhi

    2015-12-01

    This article presents a method for sensitive, fast and quantitative determination of melamine in milk and dairy products using high-field asymmetric ion mobility spectrometry (FAIMS). The solid-phase extraction (SPE) technology was used for purification after the sample was extracted by organic solvents, and followed by the analysis of FAIMS. The measurement parameters and variables that affect the FAIMS detection have been investigated, and optimum conditions have been obtained as follows: the carrier gas flow rate is 1.6 L min(-1), the headspace sampler temperature is 150 °C, the pressure is 1 atm, and the humidity is 2.0 g m(-3). The results showed that the SPE-FAIMS method can detect melamine in samples with a concentration down to 0.1 mg kg(-1). The ion intensity has a linear relationship with melamine concentration in the range from 0.3 mg L(-1) to 25 mg L(-1), with a good linearity of 0.9975. The limits of detection (LOD) and limits of quantification (LOQ) are 0.1 mg kg(-1) and 0.3 mg kg(-1) in milk and dairy products, respectively, and the relative standard deviation is less than 8.0%. The results demonstrated that FAIMS has great potential as a powerful tool for food analysis and safety inspection. PMID:26041222

  19. Determination of benzodiazepines, related pharmaceuticals and metabolites in water by solid-phase extraction and liquid-chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Racamonde, Inés; Rodil, Rosario; Quintana, José Benito; Villaverde-de-Sáa, Eugenia; Cela, Rafael

    2014-07-25

    This work presents a method for the simultaneous determination of 23 benzodiazepines, metabolites and related pharmaceuticals (zolpidem, methylphenidate and ritalinic acid) by solid-phase extraction (SPE) followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Different SPE cartridges were considered: hydrophilic modified reversed-phase (Oasis HLB) and their modified versions containing also a cationic-exchange group (Oasis MCX) or anionic-exchange (Oasis MAX) funcionalities. Stability of analytes and the impact of the final eluate volume on the matrix effects on LC-MS/MS were also considered. In the final method, 100-200 mL of sample are extracted with Oasis MCX (60 mg), eluted with 5 mL of methanol (1.25% NH3) and the eluate concentrated and analyzed by LC-MS/MS. Under these conditions, LOQs were established between 0.1 and 18 ng L(-1) for influent wastewater. The use of surrogated deuterated internal standards allows obtaining recoveries in the 84-122% range. Finally the method was applied to determinate the analytes in wastewater and surface water and 10 compounds were detected in the range of 0.5-170 ng L(-1), being the ritalinic acid (the main metabolite of methylphenidate) the analyte detected in the highest concentrations. PMID:24925453

  20. Determination of gabapentin in human plasma by capillary electrophoresis-laser induced fluorescence detection with and without solid-phase extraction

    International Nuclear Information System (INIS)

    We have developed two methods for the quantitation of gabapentin in human plasma. They are based on capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) with and without solid-phase extraction (SPE) and the derivatizing reagent 5-(4,6-dichlorotriazinyl)amino fluoresencin. The conditions for derivatization, separation and extraction were investigated in detail, and the optimal labeling conditions include a temperature of 400C, a reaction time of 30 min, and the use of a borate buffer of pH 9.0 as the reaction medium. A borate buffer of pH 9.2 served as a background electrolyte for CE separations. The CE-LIF and SPE-CE-LIF methods have linear ranges of 5-200 nmol L-1 and 0.2-10 nmol L-1, respectively, and the limits of detection are 0.5 and 0.02 nmol L-1, respectively. The SPE-CE-LIF method was successfully applied to the determination of gabapentin in blood plasma samples. (author)

  1. Determination of eight pesticides of varying polarity in surface waters using solid phase extraction with multiwalled carbon nanotubes and liquid chromatography-linear ion trap mass spectrometry

    International Nuclear Information System (INIS)

    We describe a MWCNT-based method for the solid-phase extraction of eight pesticides from environmental water samples. The analytes are extracted from 100 mL samples at pH 5.0 (containing 5 mmol L?1 of KCl) by passing the solution through a column filled with 20 mg of multiwalled carbon nanotubes. Following elution, the pesticides were determined by LC and electrospray ionization hybrid quadrupole linear ion trap MS. Two selected reaction monitoring transitions were monitored per compound, the most intense one being used for quantification and the second one for confirmation. In addition, an information-dependent acquisition experiment was performed for unequivocal confirmation of positive findings. Matrix effect was not found in real waters and therefore the quantitation was carried out with calibration graphs built with solvent based standards. Except for cymoxanil, the detection and quantitation limits in surface waters are in the range from 0.3 to 9.5 ng L?1 and 1.6 to 45.2 ng L?1, respectively. Recoveries from spiked ultrapure water are ?100 %, except for the most polar pesticides methomyl and cymoxanil. The same behavior is found for real water samples (except for phosalone). The relative standard deviation is <10 % in all cases. (author)

  2. Magnetic molecularly imprinted polymer nanoparticles for the solid-phase extraction of paracetamole from plasma samples, followed its determination by HPLC

    International Nuclear Information System (INIS)

    We are presenting magnetic molecularly imprinted polymer nanoparticles (m-MIPs) for solid-phase extraction and sample clean-up of paracetamole. The m-MIPs were prepared from magnetite (Fe3O4) as the magnetic component, paracetamole as the template, methacrylic acid as a functional monomer, and 2-(methacrylamido) ethyl methacrylate as a cross-linker. The m-MIPs were then characterized by transmission electron microscopy, FT-IR spectroscopy, X-ray diffraction and vibrating sample magnetometry. The m-MIPs were applied to the extraction of paracetamole from human blood plasma samples. Following its elution from the column loaded with the m-MIPs with an acetonitrile-buffer (9:1) mixture, it was submitted to HPLC analysis. Paracetamole can be quantified by this method in the 1 ?g L?1 to 300 ?g L?1 concentration range. The limit of detection and limit of quantification in plasma samples are 0.17 and 0.4 ?g L?1. The preconcentration factor of the m-MIPs is 40. The HPLC method shows good precision (4.5 % at 50 ?g L?1 levels) and recoveries (between 83 and 91 %) from spiked plasma samples. (author)

  3. Determination of aromatic amine mutagens, PBTA-1 and PBTA-2, in river water by solid-phase extraction followed by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Moriwaki, Hiroshi; Harino, Hiroya; Hashimoto, Hiroyuki; Arakawa, Ryuichi; Ohe, Takeshi; Yoshikura, Taro

    2003-05-01

    We describe a novel method for the determination of two kinds of aromatic amine mutagens, 2-[2-(acetylamino)-4-[bis(2-methoxyethyl)-amino]-5-amino-7-bromo-4-chloro-2H-benzotriazole (PBTA-1) and 2-[2-(acetylamino)-4-[bis(2-cyanoethyl)-ethylamino]-5-amino-7-bromo-4-chloro-2H-benzotriazole (PBTA-2), in river water based on liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS-MS). A solid-phase extraction procedure was used for the extraction of PBTA-1 and PBTA-2 from river water. The procedure was rapid and the relative standard deviations were below 4%. The detection limits of PBTA-1 and PBTA-2 in river water using the proposed method were found to be 1 and 2 ng/l, respectively. The compounds were detected by this method in river water taken from two sites in the Yodo River system at the ng/l level. PMID:12800941

  4. Dispersive solid phase extraction combined with ion-pair ultra high-performance liquid chromatography tandem mass spectrometry for quantification of nucleotides in Lactococcus lactis

    DEFF Research Database (Denmark)

    Magdenoska, Olivera; Martinussen, Jan

    2013-01-01

    Analysis of intracellular metabolites in bacteria is of utmost importance for systems biology and at the same time analytically challenging due to the large difference in concentrations, multiple negative charges, and high polarity of these compounds. To challenge this, a method based on dispersive solid phase extraction with charcoal and subsequent analysis with ion-pair liquid chromatography coupled with electrospray ionization tandem mass spectrometry was established for quantification of intracellular pools of the 28 most important nucleotides. The method can handle extracts where cells leak during the quenching. Using a Phenyl-Hexyl column and tributylamine as volatile ion-pair reagent, sufficient retention and separation was achieved for mono-, di-, and triphosphorylated nucleotides. Stable isotope labeled nucleotides were used as internal standards for some analytes. The method was validated by determination of the recovery, matrix effects, accuracy, linearity, and limit of detection based on spiking of medium blank as well as standard addition to quenched Lactococcus lactis samples. For standard addition experiments, the isotope-labeled standards needed to be added in similar or higher concentrations as the analytes. L. lactis samples had an energy charge of 0.97±0.001 which was consistent with literature, whereas some differences were observed compared with legacy data based on 33P labeling.

  5. Determination of neonicotinoid pesticides residues in agricultural samples by solid-phase extraction combined with liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Xie, Wen; Han, Chao; Qian, Yan; Ding, Huiying; Chen, Xiaomei; Xi, Junyang

    2011-07-15

    This work reports a new sensitive multi-residue liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for detection, confirmation and quantification of six neonicotinoid pesticides (dinotefuran, thiamethoxam, clothiandin, imidacloprid, acetamiprid and thiacloprid) in agricultural samples (chestnut, shallot, ginger and tea). Activated carbon and HLB solid-phase extraction cartridges were used for cleaning up the extracts. Analysis is performed by LC-MS/MS operated in the multiple reaction monitoring (MRM) mode, acquiring two specific precursor-product ion transitions per target compound. Quantification was carried by the internal standard method with D(4)-labeled imidacloprid. The method showed excellent linearity (R(2)?0.9991) and precision (relative standard deviation, RSD?8.6%) for all compounds. Limits of quantification (LOQs) were 0.01 mg kg(-1) for chestnut, shallot, ginger sample and 0.02 mg kg(-1) for tea sample. The average recoveries, measured at three concentrations levels (0.01 mg kg(-1), 0.02 mg kg(-1) and 0.1 mg kg(-1) for chestnut, shallot, ginger sample, 0.02 mg kg(-1), 0.04 mg kg(-1) and 0.2 mg kg(-1) for tea sample), were in the range 82.1-108.5%. The method was satisfactorily validated for the analysis of 150 agricultural samples (chestnut, shallot, ginger and tea). Imidacloprid and acetamiprid were detected at concentration levels ranging from 0.05 to 3.6 mg kg(-1). PMID:21641601

  6. Application of solid phase extraction with the use of silica modified with polyaniline film for pretreatment of samples from plant material before HPLC determination of triterpenic acids.

    Science.gov (United States)

    Sowa, Ireneusz; Wójciak-Kosior, Magdalena; Rokicka, Kamila; Kocjan, Ryszard; Szymczak, Gra?yna

    2014-05-01

    The new sorbent based on silica gel coated with a film of polyaniline (Si-PANI) was obtained in a process of in situ polymerization directly on carrier particles and its potential application for pretreatment of plant material samples with the use of solid phase extraction (SPE) was investigated. Parameters such as cartridge conditioning, the volume and concentration of the sample, the type and volume of the elution solvent were optimized and compared with parameters obtained for RP-18 and aminopropyl silica cartridges. The high recovery values above 97% after the SPE procedure with the use of Si-PANI cartridges proves their utility for analysis of triterpenic acids. The sorbent tested was successfully used for clean-up of extracts from Salvia officinalis L., Syzygium aromaticum (L.) Merrill., and Origanum vulgare L. prior to HPLC-DAD determination of oleanolic, ursolic and betulinic acid. The efficiency of sample purification was verified by monitoring of chromatograms in the region between 190 nm and 400 nm during the gradient elution. The fewest components or their lowest concentrations were observed for all the investigated samples after the SPE procedures. PMID:24720961

  7. Determination of salbutamol using on-line solid-phase extraction and sequential injection analysis. Comparison of chemiluminescence and fluorescence detection.

    Science.gov (United States)

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

    2003-06-01

    Determination of salbutamol using sequential injection analysis (SIA) with chemiluminescence and fluorescence detection has been devised. The chemiluminescence signal was emitted during the oxidation of salbutamol by potassium permanganate in sulfuric acid medium. Sodium polyphosphate was used as chemiluminescence enhancer. The fluorescence signal (excitation wavelength 230 nm) was also measured in sulfuric acid medium. Both detection techniques were compared with respect to the application of the methods to the determination of salbutamol in biological materials. The sample pre-treatment takes place directly in the SIA system, when salbutamol is adsorbed on the solid-phase (Baker-carboxylic acid) microcolumn integrated into the system. Sulfuric acid serves both as the reagent and the eluent. The lab-made SIA system consisted of a 2.5-mL Cavro syringe pump, ten-port Vici Valco selection valve and Spectra-Physics FS 970 fluorescence detector, which was lab-modified for chemiluminescence detection. The system was controlled by a PC using originally compiled LabVIEW-supported software. Concentrations, volumes of reagents and flow rates were optimised by a simplex method. Salbutamol was determined in the linear range 0.05-10 microg mL(-1) (RSD 1.53%), with the detection limit (3 sigma) 0.03 microg mL(-1) and sample throughput of 42 samples per hour with chemiluminescence detection in standard solutions. The fluorescence detection enabled the determination of salbutamol in standard solutions in the linear range 0.5-100 microg mL(-1) (RSD 2.69%), with the detection limit 0.2 microg mL(-1) and sample throughput of 24 h(-1). The proposed methods were applied to the determination of salbutamol in human serum and urine. However, serum is a very complicated matrix and the SIA-SPE analysis did not provide satisfactory results. It was possible to determine salbutamol in human urine using this technique. Better recovery was achieved with fluorescence detection. PMID:12819847

  8. Cold vapor atomic absorption spectrometric determination of cadmium after solid phase extraction on modified TiO2 nanoparticles

    Scientific Electronic Library Online (English)

    Reza Hafezi, Moghaddam; Ali Mohammad Haji, Shabani; Shayessteh, Dadfarnia; Neda, Baghban.

    2014-11-01

    Full Text Available O cádmio de uma amostra aquosa foi quantitativamente adsorvido em uma microcoluna empacotada com cadion imobilizado em nanopartículas de TiO2 recobertas por dodecilsulfato de sódio. O cádmio retido foi eluido com uma solução de ácido clorídrico 2,5 mol L-1 e medido por espectroscopia de absorção atô [...] mica com vapor frio (CVAAS). As influências de diferentes variáveis, como pH, taxas de fluxo da amostra e do eluente, quantidade do sorvente e volume da amostra, na recuperação do cádmio foram investigadas. Sob condições ótimas, um volume de 200 mL de amostra resultou em um fator de pré-concentração de 100. A precisão (RSD%, n = 8) em 0,05 µg L-1 de cádmio foi 3,6% e o limite de detecção, baseado em três vezes o desvio padrão do branco (3Sb), foi de 1,3 ng L-1. O método foi aplicado com sucesso à determinacão de cádmio em amostras de arroz, peixe, leite e água. Abstract in english Cadmium was quantitatively adsorbed from aqueous sample onto a microcolumn packed with cadion immobilized on sodium dodecyl sulfate-coated TiO2 nanoparticles. The retained cadmium was eluted with 2.5 mol L-1 hydrochloric acid solution and measured by cold vapor atomic absorption spectrometry (CVAAS) [...] . The influences of different variables such as pH, sample and eluent flow rates, amount of the sorbent and volume of the sample on the recovery of cadmium were investigated. Under the optimum conditions, a sample volume of 200 mL resulted in a preconcentration factor of 100. The precision (RSD%, n = 8) at the 0.05 µg L-1 level of cadmium was 3.6% and the limit of detection based on three times the standard deviation of blank solution (3Sb) was 1.3 ng L-1. The method was successfully applied to the determination of cadmium in rice, fish, milk, and water samples.

  9. Use of activated charcoal in a solid-phase extraction technique for analysis of pesticide residues in tomatoes

    Scientific Electronic Library Online (English)

    Beatriz I. A., Kaipper; Luiz A. S., Madureira; Henry X., Corseuil.

    2001-08-01

    Full Text Available No presente trabalho foram desenvolvidos métodos de extração e purificação a fim de determinar e monitorar as concentrações dos pesticidas organofosforados mais utilizados em tomates na grande Florianópolis. A técnica de EFS com carvão ativo foi utilizada para a purificação e recuperação dos pestici [...] das metamidofós, acefato, malation e paration metílico. Os solventes para a extração e eluição foram escolhidos após diversas análises, sendo que os melhores resultados foram alcançados através da extração dos pesticidas com acetato de etila e eluição com CH2Cl2 - acetato de etila (7:3). A média recuperada dos analitos das matrizes fortificadas com 0,20 - 0,60 mig g-1 variou entre 85,2 e 100 %, com coeficientes de variação entre 1,3 e 6,3 %. Os limites de detecção foram de 0,04 a 0,12 ng g-1. O adsorvente carvão ativo mostrou-se eficiente para a purificação da matriz de tomate e para a recuperação quantitativa dos analitos, especialmente os mais polares. Abstract in english The present work describes extraction and purification methods that were developed to determine and to monitor the content of organophosphorus pesticides in tomato crops from the agricultural district of Florianópolis, Brazil. SPE technique with activated charcoal was used for purification and recov [...] ery of the pesticides methamidophos, acephate, malation and methyl parathion. The solvents used for sample extraction and elution were chosen after several comparative tests. Best results were achieved using ethyl acetate for extraction and dichloromethane - ethyl acetate (7:3) for elution. Average recoveries from the matrices fortified with 0.20 to 0.60 mug g-1 ranged from 85.2 to 100 % with overall coefficients of variation of 1.3 to 6.3 %. The limits of detection of the method varied between 0.04 and 0.12 ng g-1. Activated charcoal demonstrated to be efficient for tomato matrix purification and for quantitative recovery of the analytes.

  10. Evaluation of magnetic nanoparticles to serve as solid-phase extraction sorbents for the determination of endocrine disruptors in milk samples by gas chromatography mass spectrometry.

    Science.gov (United States)

    Synaridou, Maria-Evangelia S; Sakkas, Vasilios A; Stalikas, Constantine D; Albanis, Triantafyllos A

    2014-06-27

    A rapid magnetic solid-phase extraction (MSPE) is proposed based on C18-functionalized magnetic silica nanoparticles as sorbents, for the determination of endocrine disruptors - 20 organochlorine pesticides and 6 polychlorinated biphenyls - in milk samples. Magnetic nanoparticles are characterized by several techniques, such as Scanning Electron Microscopy, X-Ray diffraction, Brunauer-Emmett-Teller and Fourier transform-infrared. The MSPE is performed by dispersion of the Fe3O4@SiO2@C18 nanoparticles in milk samples with sonication, after protein precipitation. Then, the sorbent is collected by applying an external magnetic field and the analytes are desorbed by n-hexane. Several parameters affecting the extraction efficiency of target analytes by the magnetic nanoparticles are investigated, including washing and elution solvents, amount of sorbents, time of extraction and elution, sample and elution solvent volume. The proposed method is optimized by means of experimental design and response surface methodology. When coupled with gas chromatography-mass spectrometry detection and under optimum extraction conditions, average recoveries of target analytes are found to be in the range of 79% to 116%. The proposed MSPE-GC-MS analytical method has a linear calibration curve for all target analytes with coefficients of determination to range from 0.9950 to 0.9999. The limits of quantification are found to be between 0.2 and 1?g/L ensuring compliance with the maximum residue limits established by European Commission and Codex Alimentarius, for OCPs and PCBs residues in milk. The proposed method is applied to the determination of target analytes in milk samples from local markets. PMID:24837417

  11. [Analysis of 112 pesticide residues in vegetables using dispersive-solid phase extraction and gas chromatography-triple quadrupole mass spectrometry].

    Science.gov (United States)

    Shi, Jiawei; Li, Jige; Wang, Yufei; Fan, Jianzhong

    2012-06-01

    A method was developed and validated for the simultaneous analysis of 112 pesticide residues in vegetables by gas chromatography coupled with triple quadrupole mass spectrometry (GC-QQQ-MS/MS). It is demonstrated that the optimized conditions could provide a more accurate quantitation and lower limit of quantification of the analysis by dispersive-solid phase extraction (D-SPE) cleanup. The samples were extracted with acetonitrile and toluene (8: 1, v/v), and cleaned up by D-SPE. To every 5 mL extraction solution, 0.8 g MgSO4, 0.05 g graphitized carbon black (GCB), 0.1 g ethylenediamine-N-propyl silyl (PSA) and 0.05 g C18 were added. The extracts were analyzed by GC-QQQ-MS/MS using internal standard method. The recoveries of the 112 pesticides at three spiked levels of 20, 50 and 200 microg/kg were ranged from 53.1% to 138.7%, and among which those of 86 pesticides were from 65.0% to 120.0%. The relative standard deviations (RSD) were less than 12%. The limits of quantifications (LOQs) (signal/noise at 10) were between 1.6 and 13.4 microg/kg. The vegetable samples collected from the market such as garlic chives, cucumber and purple cabbage were analyzed, and the residues of triazophos and fenpropathrin were detected in some of these samples. The method can be applied to the routine analysis for the determination of the 112 pesticides in vegetable samples. PMID:23016295

  12. [Determination of 23 phthalate esters in scallion and other vegetables by solid-phase extraction coupled with gas chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Wang, Huifeng; Dong, Xiaohai; Jia, Bin; Feng, Shuhui; Liu, Jinxi; Zhong Hongjian

    2015-05-01

    A method for the simultaneous determination of 23 phthalate esters in vegetables by solid-phase extraction coupled with gas chromatography-triple quadrupole mass spectrometry (SPE-GC-MS/MS) was developed and evaluated. The samples were extracted with acetonitrile, and cleaned-up with glass Florisil SPE columns, and diluted with n-hexane. The separation was performed on a DB-5MS UI capillary column (30 m x 0.25 mm x 0.25 µm) with temperature programming. The identification and quantification were performed by GC-MS/MS in selected reaction monitoring (SRM) mode. The external standard method was used. The processes of extraction and clean-up of scallion and other vegetables were investigated, and the chromatographic and MS parameters were optimized. The matrix effect was compensated by matrix spiked calibration. The extraction processes were investigated. The calibration curves of the phthalate esters showed good linearities in the ranges of 0.02-1 mg/L (0.1-5 mg/L for diisononyl phthalate (DINP) and diisodecyl-o-phthalate (DIDP)) with the correlation coefficients (r) over 0.99 except for bis(2-methoxyethyl) phthalate (DMEP). The limits of detection of phthalate esters in samples ranged from 0.01 to 0.05 mg/kg (S/N = 3) and the limits of quantification ranged from 0.02 to 0.1 mg/kg (S/N = 10). The average recoveries of the 23 analytes spiked in scallions ranged from 81.3% to 104.2% with the relative standard deviations (RSDs, n = 6) of 3.2%-11.2%. The method is suitable for the determination of the 23 phthalate esters simultaneously in vegetables with easy operation, high accuracy and precision. PMID:26387215

  13. Screening procedure for organochlorine and organophosphorus pesticide residues in milk using matrix solid phase dispersion (MSPD) extraction and gas chromatographic determination.

    Science.gov (United States)

    Schenck, F J; Wagner, R

    1995-01-01

    A rapid technique for the extraction and gas chromatographic determination of five organochlorine and five organophosphorus pesticide residues in milk is described. Milk (5.0 ml) is blended with 2.0 g of C18 [octadecylsilyl-derivatized silica] and 1.5 ml acetonitrile in a syringe barrel. After the aqueous phase is removed from the column by vacuum aspiration, the pesticide residues are eluted from the C18/milk matrix with acetonitrile which is then eluted through a Florisil solid phase extraction (SPE) column. The acetonitrile is evaporated under nitrogen and the residue is dissolved in petroleum ether. This extract is directly analysed for organophosphorus pesticides by gas chromatography with flame photometric detection. After further clean-up of the extract on a mini-Florisil column, the organochlorine pesticide residues are determined by gas chromatography with electron capture detection. Grade A homogenized and raw milk samples were fortified with five organochlorine and five organophosphorus pesticide residues. The average recoveries of fortified organochlorine pesticide residues (2.0-20 ppb) ranged from 76.0% to 97.8%. The average recoveries of fortified organophosphorus pesticide residues (10-50 ppb) ranged from 75.0% to 104.5%. The MSPD and the AOAC International multiresidue method for pesticides in milk produced comparable results for milk samples containing incurred organochlorine pesticide residues. The use of the MSPD method results in a 90% reduction in organic solvent consumption and a 95% reduction in the hazardous waste generated when compared with the AOAC method. PMID:7589717

  14. Analysis of pesticides residues in environmental water samples using multiwalled carbon nanotubes dispersive solid-phase extraction.

    Science.gov (United States)

    González-Curbelo, Miguel Ángel; Herrera-Herrera, Antonio V; Hernández-Borges, Javier; Rodríguez-Delgado, Miguel Ángel

    2013-02-01

    In this manuscript, a dispersive SPE method based on the use of multiwalled carbon nanotubes has been developed for the determination of 15 organophosphorus pesticides residues 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) from real environmental waters (run-off, mineral and tap water) by GC with nitrogen phosphorus detection. Factors that affect the enrichment efficiency such as sample volume, multiwalled carbon nanotubes amount, and volume of eluent were studied. The optimized method was validated in terms of matrix-matched calibration, recovery, precision, and accuracy for the three analyzed samples. In this last case, the developed Student's t test demonstrated that there were no significant differences between real and spiked concentrations. Optimum dispersive SPE conditions (extraction of 200 mL of water, pH 6.0, with 130 mg of multiwalled carbon nanotubes, elution with 25 mL of dichloromethane for run-off and tap water and 30 mL for mineral water) allowed the quantitative extraction of analytes at levels lower than the maximum residues limits legislated by the European Union, with LODs between 1.16 and 93.6 ng/L. Absolute recovery values achieved were in the range of 67-107% (RSD values <10.1%). PMID:23303564

  15. Synthesis and application of vinylpyridine containing ion-imprinted copolymer gel microbeads for Cu(II) solid-phase extraction.

    Science.gov (United States)

    Dakova, Ivanka; Karadjova, Irina; Georgieva, Ventsislava; Georgiev, George

    2012-10-01

    The influence of polymer matrix on the extraction efficiency for Cu(II) and selectivity against metal ions such as Ni(II), Cd(II), Pb(II) of Cu(II) imprinted copolymer gels was described. The functional monomers investigated include the weakly basic 4-vinylpyridine (4-VP) and its mixure with the acidic and hydrogen binding methacrylic acid. Copolymer gels were prepared by dispersion cross-linking copolymerization using Cu(II)-4-(2-pyridylazo)resorcinol complex, Cu(II), or 4-(2-pyridylazo)resorcinol as templates. The chemical structure and morphology of the Cu(II)-imprinted microbeads are defined using elemental analysis, Fourier transform infrared spectroscopy, and scanning electron microscopy. Extraction efficiencies of newly synthesized sorbents were studied by batch procedure. The prepared copolymer gel with 4-VP as monomer and Cu(II)-4-(2-pyridylazo)resorcinol complex has higher capacity and selectivity toward Cu(II) than the copolymer gels prepared using the mixture of methacrylic acid and 4-VP. This new sorbent can be used as an effective SPE material for the highly selective preconcentration and separation of Cu(II) in sea water samples. It shows high mechanical and chemical stability. PMID:22961780

  16. Ultrasound-assisted extraction and solid-phase extraction as a cleanup procedure for organochlorinated pesticides and polychlorinated biphenyls determination in aquatic samples by gas chromatography with electron capture detection.

    Science.gov (United States)

    Sun, Xiumei; Hu, Hongmei; Zhong, Zhi; Jin, Yanjian; Zhang, Xiaojun; Guo, Yuanming

    2015-02-01

    The feasibility of developing a quick, easy, efficient procedure for the simultaneous determination of organochlorinated pesticides and polychlorinated biphenyls in aquatic samples using gas chromatography with electron capture detection based on solid-phase extraction was investigated. The extraction solvent (n-hexane/acetone, cyclohexane/ethyl acetate, n-hexane/dichloromethane, n-hexane) for ultrasound-assisted solid-liquid extraction and solid-phase extraction columns (florisil, neutral alumina, acidic alumina, aminopropyl trimethoxy silane, propyl ethylenediamine, aminopropyl trimethoxy silane/propyl ethylenediamine, graphitized carbon black and silica) for cleanup procedure were optimized. The gas chromatography with electron capture detection method was validated in terms of linearity, sensitivity, reproducibility, and recovery. Mean recoveries ranged from 75 to 115% with relative standard deviations <13%. Quantification limits were 0.20-0.40 ng/g for organochlorinated pesticides and polychlorinated biphenyls. The satisfactory data demonstrated the good reproducibility of the method with relative standard deviations lower than 13%. In comparison to other related methods, this method requires less time and solvent and allows for rapid isolation of the target analytes with high selectivity. This method therefore allows for the screening of numerous samples and can also be used for routine analyses. PMID:25529797

  17. Determination of steroid hormones and related compounds in filtered and unfiltered water by solid-phase extraction, derivatization, and gas chromatography with tandem mass spectrometry

    Science.gov (United States)

    Foreman, William T.; Gray, James L.; ReVello, Rhiannon