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Sample records for solid-phase extraction adsorbent

  1. New macroporous ?-cyclodextrin functionalized ionic liquid polymer as an adsorbent for solid phase extraction with phenols.

    Science.gov (United States)

    Raoov, Muggundha; Mohamad, Sharifah; bin Abas, Mhd Radzi; Surikumaran, Hemavathy

    2014-12-01

    Cyclodextrin-ionic liquid polymer (?CD-BIMOTs-TDI) is a new class of macroporous material and has great potential to be used as an SPE adsorbent material for extraction of phenols in river water samples. Six phenols, as model analytes, were extracted on a ?CD-BIMOTs-TDI SPE cartridge, and then, eluted with 2 mL of methanol containing 1% acetic acid. The optimum experimental condition was 15 mL of sample volume (sample at pH 6) and 2 mL of methanol containing 1% acetic acid as an eluent solvent. The eluent concentration was determined by using Gas Chromatography-Flame Ionization Detector (GC-FID). Under optimized condition, high sensitivity (detection limits 0.23-0.35 µg/L) and good recoveries (87-116%) were achieved with satisfactory relative standard deviation (RSD) (0.1-1.7%). The developed ?CD-BIMOTs-TDI-SPE was then compared with other adsorbents, and the obtained results showed that the ?CD-BIMOTs-TDI exhibited higher extraction recovery due to the unique structure and properties. Finally, the ?CD-BIMOTs-TDI was applied as a solid phase extraction sorbent for phenols determination under optimized condition, in river and tap waters, prior to the GC-FID separation. PMID:25159393

  2. HPLC determination of hesperidin, diosmin and eriocitrin in Iranian lime juice using polyamide as an adsorbent for solid phase extraction.

    Science.gov (United States)

    Saeidi, Iman; Hadjmohammadi, Mohammad Reza; Peyrovi, Moazameh; Iranshahi, Mehrdad; Barfi, Behruz; Babaei, Adel Beig; Dust, Abolghasem Mohammad

    2011-09-10

    Solid phase extraction (SPE) and HPLC were used for simultaneous determination of hesperidin, diosmin and eriocitrin in Iranian lime juice samples. The method involved very simple efficient SPE with polyamide cartridge, the use of mixture of water/acetonitrile/acetic acid (78:19:3, v/v) as a mobile phase at a flow rate of 0.8 mL/min and UV detection at 280 nm. Optimum conditions for SPE were achieved using 8 mL water/methanol (85:15, v/v, pH=3) as the washing solution and 4 mL methanol for elution. SPE parameters, such as maximum loading capacity and breakthrough volume, were also determined for each analyte. Good clean-up and high>90% were observed for all analytes. Limits of detection, limits of quantification, linear range, recovery, repeatability of retention times, and peak areas for hesperidin, diosmin and eriocitrin were 0.0283-0.0512 ?g/mL, 0.0857-0.155 ?g/mL, 0.0283-105.0 ?g/mL (R² > 0.99), 93.3-98.1%, 3.2-4.7% and 2.8-3.6%, respectively. The method was applied to analysis of lime juice samples obtained from different locations of Iran. PMID:21683540

  3. Synthesis, characterization, and application of polystyrene adsorbents containing tri-n-butylphosphate for solid-phase extraction of uranium (VI) from aqueous nitrate solutions

    International Nuclear Information System (INIS)

    Polystyrene adsorbent for solid-phase extraction of U(VI) was developed through in situ copolymerization of styrene and divinylbenzene in the presence of tri-n-butylphosphate and its magnetic form was obtained by addition of fine particles of magnetite in an amount of 15 wt% of the total monomers used. The obtained adsorbents were characterized by means of scanning electron microscope, FTIR spectroscopy and X-ray powder diffraction. The adsorption behavior of U(VI) from aqueous nitrate solutions onto non-magnetic adsorbent RI (St-DVB-TBP) and its magnetic form RII (St-DVB-TBP-Fe3O4) at different experimental condition was studied using batch method. The adsorption results were found to fit Langmuir model. The magnetite-containing adsorbent showed higher uptake values relative to the corresponding magnetite-free one. The adsorption of U(VI) onto RI followed pseudo-first order kinetics whereas the adsorption onto RII followed pseudo-second order. Thermodynamic studies revealed that the adsorption process was a spontaneous exothermic reaction. Desorption of the loaded U(VI) was carried out using distilled water and found to be 97 and 93 % for RI and RII, respectively. (author)

  4. Solid Phase Micro Extraction (SPME)

    Science.gov (United States)

    1998-01-01

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

  5. 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 successfullveloped 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%.

  6. 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 0.5-100ngg(-1) and 0.05-20ngmL(-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 0.25-0.1ngg(-1) and 0.01-0.02ngmL(-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

  7. 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?gL(-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

  8. 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.

  9. 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

  10. Determination of pyrazole and pyrrole pesticides in environmental water samples by solid-phase extraction using multi-walled carbon nanotubes as adsorbent coupled with high-performance liquid chromatography.

    Science.gov (United States)

    Ma, Jiping; Lu, Xi; Xia, Yan; Yan, Fengli

    2015-02-01

    A solid-phase extraction (SPE) method using multi-walled carbon nanotubes as adsorbent coupled with high-performance liquid chromatography was developed for the determination of four pyrazole and pyrrole pesticides (fenpyroximate, chlorfenapyr, fipronil and flusilazole) in environmental water samples. Several parameters, such as extraction adsorbent, elution solvent and volume and sample loading flow rate were optimized to obtain high SPE recoveries and extraction efficiency. The calibration curves for the pesticides extracted were linear in the range of 0.05-10 ?g L(-1) for chlorfenapyr and fenpyroximate and 0.05-20 ?g L(-1) for fipronil and flusilazole, with the correlation coefficients (r(2)) between 0.9966 and 0.9990. The method gave good precisions (relative standard deviation %) from 2.9 to 10.1% for real spiked samples from reservoir water and seawater; method recoveries ranged 92.2-105.9 and 98.5-103.9% for real spiked samples from reservoir water and seawater, respectively. Limits of detection (S/N = 3) for the method were determined to be 8-19 ng L(-1). The optimized method was successfully applied to the determination of four pesticides of pyrazoles and pyrroles in real environmental water samples. PMID:24947489

  11. [Determination of six phthalate acid esters in camellia oil by gas chromatography-mass spectrometry coupled with solid-phase extraction using single-walled carbon nanotubes as adsorbent].

    Science.gov (United States)

    Zhang, Fan; Li, Zhonghai; Zhang, Ying; Huang, Zhiqiang; Wang, Xiaosong

    2014-07-01

    An analytical method based on solid-phase extraction with single-walled carbon nanotubes (SWCNTs) as adsorbent was developed for the simultaneous determination of six phthalate acid esters (PAEs) in camellia oil by gas chromatography-mass spectrometry (GC-MS). The samples were diluted by hexane and then cleaned up with a glass SWCNTs solid phase extraction (SPE) column. The PAEs were measured by GC-MS in selected ion monitoring (SIM) mode, using external standard method for quantitative analysis. The important factors affecting extraction efficiency, such as the dilution volume of hexane, the type of adsorbent material, the dosage of SWCNTs, the volume of wash solution, the type and volume of elution solution were optimized. The optimal conditions were as follows: the dilution volume of hexane was 5 mL, the dosage of SWCNTs was 0.6 g, the wash solution was 20 mL hexane, and the elution solution was 5 mL toluene. The six PAEs had a good linear range from 0.05 mg/L to 1.0 mg/L, with the correlation coefficients (r) all above 0.999 9. The average recoveries of the six targets in spiked camellia oil (from 0.05 mg/kg to 1.0 mg/kg) ranged from 86.4% to 111.7% with the relative standard deviations (RSDs) from 4.2% to 10.4%. The developed method is accurate, quick and suitable for the determination of the six PAEs in camellia oil. PMID:25255566

  12. Magnetic solid phase extraction of non-ionic surfactants from water

    International Nuclear Information System (INIS)

    Magnetic solid phase extraction was tested for the preconcentration of non-ionic surfactants based on oxyethylated nonylphenol, aliphatic alcohols and hydrogenated fatty acid methyl esters from water. Magnetic hydrophobic adsorbents exhibited the best extraction characteristics. Surfactants with the middle oxyethylation level were extracted efficiently while the extraction of surfactants with low and high oxyethylation levels was very low

  13. 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

  14. 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

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yaping [Beijing National Laboratory of Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Graduate School, University of Chinese Academy of Sciences, Beijing 100049 (China); Qi, Li, E-mail: qili@iccas.ac.cn [Beijing National Laboratory of Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Shen, Ying [Beijing National Laboratory of Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Graduate School, University of Chinese Academy of Sciences, Beijing 100049 (China); Ma, Huimin [Beijing National Laboratory of Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-02-06

    Graphical abstract: -- Highlights: •The core@shell Fe{sub 3}O{sub 4}@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 Fe{sub 3}O{sub 4}@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 Fe{sub 3}O{sub 4}@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{sup ?1} for diphenols and 1.56–100 ?g L{sup ?1} for PAHs) with good linearity (r{sup 2} ? 0.989) and low detection limits (0.34–16.67 ?g L{sup ?1} for diphenols and 0.26–0.52 ?g L{sup ?1} for PAHs) were achieved. The advantage of the developed method is that the Fe{sub 3}O{sub 4}@Au NPs could be reutilized for preconcentrating diverse target analytes in different SPE modes sequentially simply through treatment with desired thiol-containing ligands.

  15. Solid-phase extraction (SPE) of Iron using Lanthanum Silicate ion exchange

    International Nuclear Information System (INIS)

    Solid-phase extraction (SPE) is gaining wide use as an effective and speedy technique which reduces solvent usage, disposal costs and extraction time. The analyte is adsorbed from solution onto a solid adsorbent, which is followed by elution of the analyte with a solvent appropriate for instrumental analysis. However, there is an increasing need for new selective adsorbents to expand the area of this technique. Lanthanum silicate ion exchanger, which shows unusual selectivity elements and in this study, it was employed to develop a SPE method for iron ion. Special experiments such as determination of distribution coefficient for iron ion in different solvent systems have been determined

  16. Solid phase micro-extraction in environmental atmosphere

    International Nuclear Information System (INIS)

    Solid phase micro-extraction (SPME) is an advanced technique of sample pretreatment in environmental atmosphere analysis, i.e., a sampling method of extracting volatile organic compounds from environmental gas. According to the primary survey on the theory and application of SPME, a suitable extraction tip, i.e., a coated fused silica fiber, is selected to construct a SPME apparatus. This SPME apparatus is used to extract volatile organic compounds from environmental atmosphere and a qualitative detection is conducted in gas chromatography-mass spectrometer system. Good experimental results are obtained

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

    Energy Technology Data Exchange (ETDEWEB)

    Hamed, Mostafa Mohamed; Attallah, Mohamed Fathy; Metwally, Sayed Sayed [Atomic Energy Authority, Cairo (Egypt). Hot Labs. and Waste Management Center

    2014-07-01

    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 Co{sup 2+}, Sr{sup 2+} and Cs{sup +} 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 Co{sup 2+}, Sr{sup 2+} and Cs{sup +} 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 Co{sup 2+}, Sr{sup 2+} and Cs{sup +} 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 {sup 60}Co and {sup 134}Cs from liquid radioactive waste. The parameters can be used for designing a plant for treatment of wastewater economically.

  18. 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 2iations (R.S.D.) in the range of 2.1-7.8%

  19. Automation of Fluorous Solid-Phase Extraction for Parallel Synthesis

    OpenAIRE

    Zhang, Wei; Lu, Yimin

    2006-01-01

    An automatic fluorous solid-phase extraction (F-SPE) technique is developed by using FluoroFlash SPE cartridges on the RapidTrace workstation. A 10-module workstation has the capability to complete a maximum of one hundred SPEs each round in 1–2 h. Another important feature of the RapidTrace system is that it has the capability to load slurry samples onto the F-SPE cartridges. The F-SPE cartridge charged with 2 g of fluorous silica gel is used to purify up to 200 mg of crude sample. Sample ...

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

    Science.gov (United States)

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

    2015-09-01

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

  1. 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)

  2. 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

  3. Highly selective solid-phase extraction of trace Pd(II) by murexide functionalized halloysite nanotubes

    International Nuclear Information System (INIS)

    Graphical abstract: Murexide functionalized halloysite nanotubes have been developed to separate and concentrate trace Pd(II) from aqueous samples. Parameters that affected the sorption and elution efficiency were studied in column mode, and the new adsorbent presented high selectivity and adsorption capacity for the solid phase extraction of trace Pd(II). Highlights: ? Murexide modified halloysite nanotubes as adsorbent has been reported originally. ? This adsorbent has a unique selectivity for Pd(II) at pH 1.0. ? This adsorbent had high adsorption capacity for Pd(II). ? The precision and accuracy of the method are satisfactory. - Abstract: The originality on the high efficiency of murexide modified halloysite nanotubes as a new adsorbent of solid phase extraction has been reported to preconcentrate and separate Pd(II) in solution samples. The new adsorbent was confirmed by Fourier transformed infrared spectra, X-ray diffraction, scanning electron microscope, transmission electron microscope and N2 adsorption–desorption isotherms. Effective preconcentration conditions of analyte were examined using column procedures prior to detection by inductively coupled plasma-optical emission spectrometry (ICP-OES). The effects of pH, the amount of adsorbent, the sample flow rate and volume, the elution condition and the interfering ions were optimized in detail. Under the optimized conditions, Pd(II) could be retained on the column at pH 1.0 and quantitativcolumn at pH 1.0 and quantitatively eluted by 2.5 mL of 0.01 mol L?1 HCl–3% thiourea solution at a flow rate of 2.0 mL min?1. The analysis time was 5 min. An enrichment factor of 120 was accomplished. Common interfering ions did not interfere in both separation and determination. The maximum adsorption capacity of the adsorbent at optimum conditions was found to be 42.86 mg g?1 for Pd(II). The detection limit (3?) of the method was 0.29 ng mL?1, and the relative standard deviation (RSD) was 3.1% (n = 11). The method was validated using certified reference material, and has been applied for the determination of trace Pd(II) in actual samples with satisfactory results.

  4. Highly selective solid-phase extraction of trace Pd(II) by murexide functionalized halloysite nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Li Ruijun; He Qun; Hu Zheng; Zhang Shengrui [Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou 730000 (China); Zhang Lijun [Faculty of Science and Engineer, Curtin University, Perth, WA 6845 (Australia); Chang Xijun, E-mail: lirj2010@lzu.edu.cn [Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou 730000 (China)

    2012-02-03

    Graphical abstract: Murexide functionalized halloysite nanotubes have been developed to separate and concentrate trace Pd(II) from aqueous samples. Parameters that affected the sorption and elution efficiency were studied in column mode, and the new adsorbent presented high selectivity and adsorption capacity for the solid phase extraction of trace Pd(II). Highlights: Black-Right-Pointing-Pointer Murexide modified halloysite nanotubes as adsorbent has been reported originally. Black-Right-Pointing-Pointer This adsorbent has a unique selectivity for Pd(II) at pH 1.0. Black-Right-Pointing-Pointer This adsorbent had high adsorption capacity for Pd(II). Black-Right-Pointing-Pointer The precision and accuracy of the method are satisfactory. - Abstract: The originality on the high efficiency of murexide modified halloysite nanotubes as a new adsorbent of solid phase extraction has been reported to preconcentrate and separate Pd(II) in solution samples. The new adsorbent was confirmed by Fourier transformed infrared spectra, X-ray diffraction, scanning electron microscope, transmission electron microscope and N{sub 2} adsorption-desorption isotherms. Effective preconcentration conditions of analyte were examined using column procedures prior to detection by inductively coupled plasma-optical emission spectrometry (ICP-OES). The effects of pH, the amount of adsorbent, the sample flow rate and volume, the elution condition and the interfering ions were optimized in detail. Under the optimized conditions, Pd(II) could be retained on the column at pH 1.0 and quantitatively eluted by 2.5 mL of 0.01 mol L{sup -1} HCl-3% thiourea solution at a flow rate of 2.0 mL min{sup -1}. The analysis time was 5 min. An enrichment factor of 120 was accomplished. Common interfering ions did not interfere in both separation and determination. The maximum adsorption capacity of the adsorbent at optimum conditions was found to be 42.86 mg g{sup -1} for Pd(II). The detection limit (3{sigma}) of the method was 0.29 ng mL{sup -1}, and the relative standard deviation (RSD) was 3.1% (n = 11). The method was validated using certified reference material, and has been applied for the determination of trace Pd(II) in actual samples with satisfactory results.

  5. Determination of metals in highly saline matrices by solid phase extraction and slurry sampling ICP/AES

    OpenAIRE

    MENTASTI, Edoardo; ABOLLINO, Ornella; Bruzzoniti, Maria Concetta; ACETO, Maurizio; SARZANINI, Corrado

    1998-01-01

    Matrix removal and preconcentration of metals from liquid samples were obtained with a solid-phase extraction/slurry-sampling procedure applied to inductively coupled plasma-atomic emission spectrometry (ICP-AES) detection. A polymeric, adsorbing resin (Amberlite XAD-2), dispersed in the sample, was used for total sorption of analytes previously complexed with a dithiocarbamate ligand. After filtration, the resin was recovered and re-dispersed by means of a non-ionic surfactant; metals retain...

  6. Spectrometric Determination of Rhodamine B in Chili Powder After Molecularly Imprinted Solid Phase Extraction

    International Nuclear Information System (INIS)

    This paper reports a method using molecularly imprinted polymers that are grafted onto the surface of carboxyl-modified multi-walled carbon nanotubes as the solid-phase extraction adsorbents to detect Rhodamine B in chili powder samples. The polymers were characterized by FTIR and TGA. Various parameters which probably influence efficiency of extraction were optimized. The analytical parameters such as precision, accuracy and linear working range were also determined in optimal experimental conditions. And the proposed method was applied to analysis of Rhodamine B in chili powder samples. The limits of detection and quantification were 2.57 and 8.56 ?g/g, respectively. The recoveries for analytes were higher than 95% and relative standard deviation values were found to be in the range of 0.83-4.15%. This method was successfully applied for the determination of Rhodamine B

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

    Science.gov (United States)

    Sauer, Richard; Rutz, Jeffrey; Schultz, John

    2005-01-01

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

  8. 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.

  9. 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.

  10. 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

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

    International Nuclear Information System (INIS)

    The simple and rapid pre-concentration techniques viz. cloud point extraction (CPE) and solid phase extraction (SPE) were applied for the determination of As3+ and total inorganic arsenic (iAs) in surface and ground water samples. The As3+ was formed complex with ammonium pyrrolidinedithiocarbamate (APDC) and extracted by surfactant-rich phases in the non-ionic surfactant Triton X-114, after centrifugation the surfactant-rich phase was diluted with 0.1 mol L-1 HNO3 in methanol. While total iAs in water samples was adsorbed on titanium dioxide (TiO2); after centrifugation, the solid phase was prepared to be slurry for determination. The extracted As species were determined by electrothermal atomic absorption spectrometry. The multivariate strategy was applied to estimate the optimum values of experimental factors for the recovery of As3+ and total iAs by CPE and SPE. The standard addition method was used to validate the optimized methods. The obtained result showed sufficient recoveries for As3+ and iAs (>98.0%). The concentration factor in both cases was found to be 40.

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

    Energy Technology Data Exchange (ETDEWEB)

    Baig, Jameel A., E-mail: jab_mughal@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080, Sindh (Pakistan); Kazi, Tasneem G., E-mail: tgkazi@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080, Sindh (Pakistan); Shah, Abdul Q., E-mail: aqshah07@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080, Sindh (Pakistan); Arain, Mohammad B. [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080, Sindh (Pakistan); Afridi, Hassan I., E-mail: hassanimranafridi@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080, Sindh (Pakistan); Kandhro, Ghulam A., E-mail: gakandhro@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080, Sindh (Pakistan); Khan, Sumaira, E-mail: skhanzai@gmail.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080, Sindh (Pakistan)

    2009-09-28

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

  13. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Ensafi, Ali A. [College of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)], E-mail: Ensafi@cc.iut.ac.ir; Ghaderi, Ali R. [College of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2007-09-05

    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 HNO{sub 3} 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 {mu}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 HNO{sub 3} 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{sup -1} Cd(II), with an enrichment factor of 1000. The calibration graph was linear in the range of 1-2000 ng mL{sup -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.

  15. 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.

  16. Mixed micelle cloud point-magnetic dispersive ?-solid phase extraction of doxazosin and alfuzosin

    Science.gov (United States)

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

    2015-01-01

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

  17. Selective separation of active inhibitors of epidermal growth factor receptor from Caragana jubata by molecularly imprinted solid-phase extraction.

    Science.gov (United States)

    Zhu, Lili; Xu, Xiaojie

    2003-04-01

    A feasibility research was performed to study the possibilities of using a molecularly imprinted polymer as sorbent material in solid-phase extraction for the separation of active inhibitors of epidermal growth factor receptor (EGRF) from Caragana Jubata, a Chinese traditional Tibetan medicine. A molecularly imprinted polymer using quercetin, an active anti-EGFR inhibitor (IC50 = 15 microM), as the template and acrylamide as the functional monomer was prepared. The polymer was evaluated as a selective sorbent in molecularly imprinted solid-phase extraction. The EtOAc extract of Caragana Jubata was loaded on the polymer, and two novel active anti-EGFR inhibitors were found to be selectively retained after washing the polymer with appropriate solvent to disrupt the non-specific interactions occurring between the sample and the polymer matrix, which were identified as (E)-piceatannol (IC50 =4.9 microM) and butein (IC50 = 10 microM). The present work affords us a new potential method for selective separation of bioactive components from herb by using molecularly imprinted polymer as a solid-phase extraction adsorbent. PMID:12741595

  18. Automated headspace solid-phase dynamic extraction to analyse the volatile fraction of food matrices

    OpenAIRE

    BICCHI, Carlo; SGORBINI, BARBARA; RUBIOLO, Patrizia; LIBERTO, Erica; CORDERO, Chiara Emilia Irma

    2004-01-01

    High concentration capacity headspace techniques (headspace solid-phase microextraction (HS-SPME) and headspace sorptive extraction (HSSE)) are a bridge between static and dynamic headspace, since they give high concentration factors as does dynamic headspace (D-HS), and are as easy to apply and as reproducible as static headspace (S-HS). In 2000, Chromtech (Idstein, Germany) introduced an inside-needle technique for vapour and liquid sampling, solid-phase dynamic extraction (SPDE), also know...

  19. 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.

  20. Solid phase extraction of uranium(VI) onto benzoylthiourea-anchored activated carbon

    International Nuclear Information System (INIS)

    A new solid phase extractant selective for uranium(VI) based on benzoylthiourea anchored to activated carbon was developed via hydroxylation, amidation and reaction with benzoyl isothiocyanate in sequence. Fourier transform infrared spectroscopy and total element analysis proved that benzoylthiourea had been successfully grafted to the surface of the activated carbon, with a loading capacity of 1.2 mmol benzoylthiourea per gram of activated carbon. The parameters that affect the uranium(VI) sorption, such as contact time, solution pH, initial uranium(VI) concentration, adsorbent dose and temperature, have been investigated. Results have been analyzed by Langmuir and Freundlich isotherm; the former was more suitable to describe the sorption process. The maximum sorption capacity (82 mg/g) for uranium(VI) was obtained at experimental conditions. The rate constant for the uranium sorption by the as-synthesized extractant was 0.441 min-1 from the first order rate equation. Thermodynamic parameters (?H0 = -46.2 kJ/mol; ?S0 = -98.0 J/mol K; ?G0 = -17.5 kJ/mol) showed the adsorption of an exothermic process and spontaneous nature, respectively. Additional studies indicated that the benzoylthiourea-anchored activated carbon (BT-AC) selectively sorbed uranyl ions in the presence of competing ions, Na+, Co2+, Sr2+, Cs+ and La3+.

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

    Science.gov (United States)

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

    2011-10-30

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

  2. 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

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

    Science.gov (United States)

    Zhou, Zhengwei; Jiang, Jia Qian

    2012-07-01

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

  4. 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).

  5. A simplified radiometabolite analysis procedure for PET radioligands using a solid phase extraction with micellar medium

    International Nuclear Information System (INIS)

    A solid phase extraction method has been developed for simple and high-speed direct determination of PET radioligands in plasma. Methods: This methodology makes use of a micellar medium and a solid-phase extraction cartridge for displacement of plasma protein bound radioligand and separation of PET radioligands from their radiometabolites without significant preparation. The plasma samples taken from monkey or human during PET measurements were mixed with a micellar eluent containing an anionic surfactant sodium dodecyl sulphate and loaded onto SPE cartridges. The amount of radioactivity corresponding to parent radioligand (retained on the cartridge) and its radioactive metabolites (eluted with micellar eluent) was measured. Results: Under the optimized conditions, excellent separation of target PET radioligands from their radiometabolites was achieved with a single elution and short run-time of 1 min. This method was successfully applied to study the metabolism for 11C-labelled radioligands in human or monkey plasma. The amount of parent PET radioligands estimated by micellar solid phase extraction strongly corresponded with that determined by radio-LC. The improved throughput permitted the analysis of a large number of plasma samples (up to 13 samples per one PET study) for accurate estimation of metabolite-corrected input function during quantitative PET imaging studies. Conclusion: Solid phase extraction together with micellar medium is fast, sensitive and easy to use, and therefore it is an attractive alternative method to determine relative composition of PET radioligands in plasma

  6. Solid phase micro extraction fibers for active or passive sampling of methyl bromide during fumigations

    Science.gov (United States)

    The high diffusivity and volatility of methyl bromide make it an ideal compound for Solid Phase Micro Extraction (SPME)-based sampling of air prior to gas-chromatographic quantifications. SPME fibers can be used as active methyl bromide samplers, with high capacities and an equilibrium time of 1-2 m...

  7. 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

  8. 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.

  9. Solid phase extraction of actinides using graphene oxide beads

    International Nuclear Information System (INIS)

    Separation of actinide ions from dilute nitric acid feed solutions is important from radioactive waste remediation point of view. A large number of separation methods are available in the literature using methods such as precipitation, ion-exchange, solvent extraction, etc. Graphene oxide (GO) are reported to be a very good sorbent for actinide ions from weakly acidic feed solutions. However, it is difficult to handle GO fine particles and any chromatographic separation is bound to be difficult as the sorbent material may be finely dispersed in the aqueous phase. It was thus thought of interest to prepare GO-based resin materials in polyether sulphone (PES) by phase inversion technique. Preparation of resins by phase inversion technique has been found to be quite efficient for metal ion separation including actinide ions. In the present work, GO based PES resin beads were prepared by phase inversion technique and the uptake of actinide and lanthanide ions. In the present work, GO based beads were prepared by phase inversion technique and the uptake of actinide and lanthanide ions (such as Am(III), Eu(III), Th(IV), Pu(IV) and U(VI)) has been studied using radiotracers

  10. Magnetic solid-phase extraction based on modified ferum oxides for enrichment, preconcentration, and isolation of pesticides and selected pollutants.

    Science.gov (United States)

    Wan Ibrahim, Wan Aini; Nodeh, Hamid Rashidi; Aboul-Enein, Hassan Y; Sanagi, Mohd Marsin

    2015-07-01

    Recently, a simple, rapid, high-efficiency, selective, and sensitive method for isolation, preconcentration, and enrichment of analytes has been developed. This new method of sample handling is based on ferum oxides as magnetic nanoparticles (MNPs) and has been used for magnetic solid-phase extraction (MSPE) of various analytes from various matrices. This review focuses on the applications of modified ferum oxides, especially modified Fe3O4 MNPs, as MSPE adsorbent for pesticide isolation from various matrices. Further perspectives on MSPE based on modified Fe3O4 for inorganic metal ions, organic compounds, and biological species from water samples are also presented. Ferum(III) oxide MNPs (Fe2O3) are also highlighted. PMID:25849825

  11. Chemically modified alumina nanoparticles for selective solid phase extraction and preconcentration of trace amounts of Cd(II)

    International Nuclear Information System (INIS)

    We have developed a solid phase extraction method for the determination of cadmium ions in aqueous samples. It is based on the adsorption of Cd(II) on alumina nanoparticles coated with sodium dodecyl sulfate and modified with a newly synthesized Schiff base. Analytical parameters such as pH value, amount of adsorbent, type and concentration of eluent, flow rates of the sample and eluent, sample volume and matrix effects were optimized. Desorption is accomplished with 2 mol L-1 nitric acid. Cd(II) was then determined by flame atomic absorption spectrometry. The maximum enrichment factor is 75. Under the optimum experimental conditions, the detection limit is 0.14 ?g L-1 in original solution. The adsorption capacity of the modified sorbent is 4.90 mg g-1 for cadmium ions. The method was applied to the determination of trace quantities of Cd(II) in water, wastewater, and biological and food samples with satisfactory results. (author)

  12. Simultaneous in situ derivatization and ultrasound-assisted dispersive magnetic solid phase extraction for thiamine determination by spectrofluorimetry.

    Science.gov (United States)

    Tarigh, Ghazale Daneshvar; Shemirani, Farzaneh

    2014-06-01

    A simple and rapid method for the simultaneous in situ derivatizaion, preconcentration and extraction of thiamine (vitamin B1) as a model analyte was developed by a novel quantitative method, namely ultrasound-assisted dispersive magnetic solid phase extraction spectrofluorimetry (USA-DMSPE-FL) from different real samples. This method consists of sample preparation, in situ derivatization, exhaustive extraction and clean up by a single process. High extraction efficiency and in situ derivatization in a short period of time is the main advantages of this procedure. For this purpose, the reusable magnetic multi-wall carbon nanotube (MMWCNT) nanocomposite was used as an adsorbent for preconcentration and determination of thiamine. Thiamine was, simultaneously, in situ derivatized as thiochrome by potassium hexacyanoferrate (III) and adsorbed on MMWCNT in an ultrasonic water bath. The MMWCNTs were then collected using an external magnetic field. Subsequently, the extracted thiochrome was washed from the surface of the adsorbent and determined by spectrofluorimetry. The developed method, which has been analytically characterized under its optimal operating conditions, allows the detection of the analyte in the samples with method detection limits of 0.37 µg L(-1). The repeatability of the method, expressed as the relative standard deviation (RSD, n=6), varies between 2.0% and 4.8% in different real samples, while the enhancement factor is 197. The proposed procedure has been applied for the determination of thiamine in biological (serum and urine), pharmaceutical (multivitamin tablet and B complex syrup) and foodstuff samples (cereal, wheat flour, banana and honey) with the good recoveries in the range from 90% to 105%. PMID:24725866

  13. Determination of banned Sudan dyes in food samples by molecularly imprinted solid phase extraction - high performance liquid chromatography

    OpenAIRE

    GIRAUDI, Gianfranco; Anfossi, Laura; Viscardi, Guido; BAGGIANI, Claudio; BARAVALLE, PATRIZIA DOMENICA; GIOVANNOLI, Cristina; BAROLO, CLAUDIA

    2009-01-01

    A method for molecularly imprinted solid-phase extraction of banned Sudan azo-dyes from food samples was investigated. The molecularly imprinted polymer was obtained by suspension polymerization using 1-(4-chlorophenyl)azonaphthalen-2-ol as the mimic template. The molecular recognition properties of imprinted beads were evaluated for use as a solid-phase extraction sorbent, in order to develop a selective extraction protocol for the Sudan class of dyes. The optimised extraction protocol re...

  14. Dispersive micro-solid phase extraction based on self-assembling, ionic liquid-coated magnetic particles for the determination of clofentezine and chlorfenapyr in environmental water samples.

    Science.gov (United States)

    Peng, Bing; Zhang, Jiaheng; Lu, Runhua; Zhang, Sanbing; Zhou, Wenfeng; Gao, Haixiang

    2013-11-21

    Two ionic liquid-coated-Fe3O4 magnetic particles (IL-Fe3O4 MPs) were developed for use in two types of dispersive micro-solid phase extraction (D-?-SPE) for the high-performance liquid chromatographic analysis of clofentezine and chlorfenapyr in environmental water samples. Self-assembling IL-Fe3O4 MPs were used in D-?-SPE as adsorbents. Two D-?-SPE extraction methods, namely, direct dispersive micro-solid phase extraction (d-D-?-SPE) and in situ solvent formation-based dispersive micro-solid phase extraction (ISF-D-?-SPE), were proposed, using [C8MIM][PF6] to extract analytes through two pathways. Lower IL doses were required in the extraction process compared with those in other IL-based methods. Fe3O4 MPs can also be recycled and reused after extraction and are thus environmentally friendly. These newly developed methods were demonstrated to be feasible for use in the quantitation of clofentezine and chlorfenapyr at trace levels, with lower limit of detection values ranging from 0.4 to 0.5 ng mL(-1) for d-D-?-SPE and 0.4 ng mL(-1) for ISF-D-?-SPE. Finally, relative standard deviations of less than 6.0% were obtained. PMID:24060962

  15. Halogen bonding: A new retention mechanism for the solid phase extraction of perfluorinated iodoalkanes

    International Nuclear Information System (INIS)

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

  16. Preconcentration and separation of nickel, copper and cobalt using solid phase extraction and their determination in some real samples

    International Nuclear Information System (INIS)

    A solid phase extraction method has been developed to separate and concentrate trace amounts of nickel, cobalt and copper ions from aqueous samples for the measurement by flame atomic absorption spectrometry. By the passage of aqueous samples through activated carbon modified by dithioxamide (rubeanic acid) (DTO), Ni2+, Cu2+ and Co2+ ions adsorb quantitatively. The recoveries of analytes at pH 5.5 with 500 mg solid phase were greater than 95% without interference from alkaline, earth alkaline and some metal ions. The enrichment factor was 330. The detection limits by three sigma were 0.50 ?g L-1 for copper, 0.75 ?g L-1 for nickel and 0.80 ?g L-1 for cobalt. The loading capacity was 0.56 mg g-1 for Ni2+, 0.50 mg g-1 for Cu2+ and 0.47 mg g-1 for Co2+. The presented procedure was applied to the determination of analytes in tap, river and sea waters, vegetable, soil and blood samples with successfully results (recoveries greater than 95%, R.S.D. lower than 2% for n = 3)

  17. 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)

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

    OpenAIRE

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

    2002-01-01

    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.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 li...

  19. 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

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

    OpenAIRE

    Ask Reitzel, Lotte; Ledin, Anna

    2006-01-01

    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 meth...

  1. Determination of fungicides in residual tanning floats using solid phase micro extraction

    OpenAIRE

    Font Valle?s, Joaquim; Reyes Reyes, Maria; Cuadros, Sara; Bacardit Dalmases, Anna; Olle? Otero, Llui?s; Marsal Monge, Agusti?n

    2013-01-01

    Solid-phase microextraction (SPME) was optimized for extraction of the leather preservative agents 2-(thiocyanomethylthio)-benzothiazole (TCMTB), 4-chloro-3-methylphenol (PCMC), 2-phenylphenol (OPP), 2-Octyl-3(2H)-isothiazolone (OIT), 2-mercaptobenzothiazol (MBT) and 3-iodo-2-propynyl-butylcarbamate (IPBC) in spent tanning floats. Determination was carried out by high performance liquid chromatography (HPLC) with photo diode array detection (PDA). The following parameters were studied to ach...

  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. PHARMACOKINETIC STUDY OF RISPERIDONE: APPLICATION OF A HPLC METHOD WITH SOLID PHASE EXTRACTION

    OpenAIRE

    Pablo Torres, V.; Jacqueline Sepu?lveda, M. C.; Carlos Von Plessing, R.

    2011-01-01

    A new, simplified solid phase extraction procedure for the determination of risperidone and 9-hydroxyrisperidone in human plasma has been developed. This method involves the use of an optimized extraction protocol developed in Waters OASIS® HLB 30mg 1cc extraction columns using 1 mL of human serum. Separation was performed by HPLC using a Waters XTerra RP-18 (5 µm, 150x4,6 mm) column with a mobile phase consisting in acetonitrile - potassium dihydrogen phosphate 50 mM pH 3.4 (27/73). UV det...

  4. Determination of organophosphorus pesticides using molecularly imprinted polymer solid phase extraction

    International Nuclear Information System (INIS)

    Molecularly imprinted polymer solid phase extraction (MIP-SPE) method has been developed for the determination of organophosphorus pesticides (OPPs) in water samples. The MIP was prepared by thermo-polymerization method using methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as crosslinker, acetonitrile as porogenic solvent and quinalphos as the template molecule. The three OPPs (diazinon, quinalphos and chloropyrifos) were selected as target analytes as they are widely used in agriculture sector. Various parameters affecting the extraction efficiency of the imprinted polymers have been evaluated to optimize the selective preconcentration of OPPs from aqueous samples. The characteristics of the MIP-SPE method were validated by high performance liquid chromatography (HPLC). The accuracy and selectivity of the MIP-SPE process developed were verified using non-imprinted polymer solid phase extraction (NIP-SPE) and a commercial C18-SPE was used for comparison. The recoveries of the target analytes obtained using the MIPs as the solid phase sorbent ranged from 83% to 98% (RSDs 1.05 - 1.98 %; n=3) for water sample. The developed MIP-SPE method demonstrates that it could be applied for the determination of OPPs in water samples. (author)

  5. 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.

  6. Analysis of lead in beverage juice using mesoporous cadmium phosphate as a solid phase adsorbent.

    Science.gov (United States)

    Yin, Ping; Qu, Rongjun; Liu, Xiguang; Dong, Xiaoqi; Xu, Qiang

    2014-04-01

    Toxic heavy metals in beverages can seriously harm human health. In the present work, a facile and eco-friendly biosynthesis of mesoporous cadmium phosphate (MPCP), using bovine serum albumin (BSA), has been successfully developed. BSAs were used to regulate the nucleation and growth of cadmium phosphate; MPCP has been used for lead ions removal from juice beverage solution and it has very excellent adsorption property capacity for Pb(II). Its adsorption kinetics could be modelled by the pseudo second-order rate equation, and the thermodynamic parameters ?G, ?H and ?S were - 5.95 kJ mol(-1), 15.08 kJ mol(-1), and 68.09 J K(-1)mol(-1), respectively. Therefore, the present research work has provided an effective way for lead ion removal in drinks, and the results suggest that MPCP might be used as a promising adsorbent with high efficiency for heavy metal ion uptake in the beverage industry. PMID:24262562

  7. Solid phase extraction (SPE) and high performance liquid chromatography for fungicides

    International Nuclear Information System (INIS)

    Three types of fungicides; oxycarboxin, thiuram disulfide and captafol were analyzed by reversed-phase high performance liquid chromatography (RP-HPLC). The analysis was carried out by using on ODS Hypersil column with acetonitrile-water (40:60) mixture. Solid phase extraction (SPE) was carried out by using a 1000 mg cartridge packed with C sub 18 to extract fungicides from spiked distilled water samples. The detection limits were between 0.5 to 20 ppm for the three fungicides. The percentage recoveries were between 87 to 98%

  8. 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%.

  9. 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%.

  10. 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.

    1166-11-01

    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.

  11. 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

  12. 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.

  13. Halogen bonding: A new retention mechanism for the solid phase extraction of perfluorinated iodoalkanes

    Energy Technology Data Exchange (ETDEWEB)

    Yan Xiaoqing; Shen Qianjin; Zhao Xiaoran; Gao Haiyue; Pang Xue [College of Chemistry, Beijing Normal University, Beijing 100875 (China); Jin Weijun, E-mail: wjjin@bnu.edu.cn [College of Chemistry, Beijing Normal University, Beijing 100875 (China)

    2012-11-13

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

  14. 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.

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

    Science.gov (United States)

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

    2014-01-01

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

  16. Solid-phase extraction and HPLC determination of levamisole hydrochloride in sheep plasma

    OpenAIRE

    Du Preez, J. L.; Lotter, A. P.

    1996-01-01

    The anthelmintic, levamisole, was determined in sheep plasma by means of ion-pair solid-phase extraction (SPE) and reverse-phase liquid chromatography. The SPE columns were conditioned with 2 ml of methanol followed by 1 ml of octane sulphonic-acid buffer. After sample application, the columns were washed with 2 ml of the same buffer, followed by elution with 90/10 acetonitrile: buffer. A phenyl reversephase column (Spherisorb S5 Phenyl, 250 x 4,6 mm) was used with a mobile phase ...

  17. 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. [...

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

    OpenAIRE

    WEIZU YANG; QIUFEN HU; ZHANGJIE HUANG; JIAYUAN YIN; GANG XIE; JING CHEN

    2006-01-01

    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 r...

  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. Solid-phase extraction of mercury(II) with magnetic core-shell nanoparticles, followed by its determination with a rhodamine-based fluorescent probe

    International Nuclear Information System (INIS)

    Magnetic Fe3O4.SiO2 core shell nanoparticles containing diphenylcarbazide in the shell were utilized for solid phase extraction of Hg(II) from aqueous solutions. The Hg(II) loaded nanoparticles were then separated by applying an external magnetic field. Adsorbed Hg(II) was desorbed and its concentration determined with a rhodamine-based fluorescent probe. The calibration graph for Hg(II) is linear in the 60 nM to 7.0 ?M concentration range, and the detection limit is at 23 nM. The method was applied, with satisfying results, to the determination of Hg(II) in industrial waste water. (author)

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

    Science.gov (United States)

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

    2015-05-15

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

  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. 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 piked 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

  4. 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.

  5. Optimization of Solid Phase Micro-Extraction (SPME for Monitoring Occupational Exposure to Ethyl Benzene

    Directory of Open Access Journals (Sweden)

    H. Heidari

    2009-08-01

    Full Text Available AbstractBackground and Objectives: Analytical methods for volatile organic compounds (VOCs in different samples need extraction of compounds, by applying hazardous solvents. Solid phase micro-extraction (SPME is a solvent-free equilibrium extraction method, in which proper calibration can allow quantitative determinations of VOCs at a very good sensitivity without the use of any organic solvent. VOCs are generally present in urine only at trace levels, therefore, a sensitive procedure is needed for their trace determinations. Throughout this study, headspace solid phase micro-extraction (HS-SPME was followed by GC-FID for ethyl benzene in spiked urine was optimized.Methods: In this study, the parameters influencing SPME and gas chromatography of ethyl benzene, including extraction time, temperature, desorption temperature, desorption time, salt addition, sample pH, sample volume and sample agitation were investigated. Results: Extraction procedure was performed at 30°C for 6 min, using 0.2 gml-1 of NaCl in the sample solution. The sample volume and sample pH were optimized at 5 ml and 7 (neutral pH, respectively. Desorption of the ethyl benzene was carried out for 60 sec. at 250°C. The method was also validated with three different spiked urine samples and illustrated an appropriate reproducibility over six consecutive days as well as six within-day experiments. During this investigation, parameters of accuracy, linearity, and detection limits of the procedure were also evaluated.Conclusion: The developed method of HS- SPME-GC-FID proved to be a simple, convenient, and practical procedure, and was successfully used for measuring of ethyl benzene in spiked urine.

  6. 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.

  7. Sample cleanup using solid-phase dispersive extraction for determination of vancomycin in serum.

    Science.gov (United States)

    Sakamoto, Yasuhiro; Jinno, Yuki; Shinodzuka, Ikumi; Iwasaki, Yusuke; Ito, Rie; Saito, Koichi

    2014-01-01

    A cleanup method employing quick and simple solid-phase dispersive extraction (SPDE) was investigated for its potential use in the determination of vancomycin (VCM) in serum by liquid chromatography/mass-spectrometry (LC/MS). SPDE was observed to be more rapid than conventional cartridge-type solid-phase extraction (SPE). In addition, in the analysis of viscous samples such as serum containing many proteins, SPDE could satisfactorily remove proteins even if deproteinization was not performed beforehand. The limit of detection (S/N = 3) and the limit of quantification (S/N > 10) of VCM by LC/MS were 0.05 and 0.2 ng/mL, respectively. The average recoveries of VCM from pooled serum spiked at 2, 10, and 100 ng/mL were 90.0, 90.8, and 98.6%, respectively. The repeatabilities were 7.5, 6.8, and 2.8%, and the intermediate precision values were 8.5, 6.8, and 7.0%, respectively. This suggests that the developed analytical method combing SPDE is useful for the determination of VCM in serum. PMID:24521915

  8. Rapid solid-phase extraction and analysis of resveratrol and other polyphenols in red wine.

    Science.gov (United States)

    Hashim, Shima N N S; Schwarz, Lachlan J; Boysen, Reinhard I; Yang, Yuanzhong; Danylec, Basil; Hearn, Milton T W

    2013-10-25

    Red wine has long been credited as a good source of health-beneficial antioxidants, including the bioactive polyphenols catechin, quercetin, and (E)-resveratrol. In this paper, we report the application of reusable molecularly imprinted polymers (MIPs) for the selective and robust solid-phase extraction (SPE) and rapid analysis of (E)-resveratrol (LOD=8.87×10(-3) mg/L, LOQ=2.94×10(-2) mg/L), along with a range of other polyphenols from an Australian Pinot noir red wine. Optimization of the molecularly imprinted solid-phase extraction (MISPE) protocol resulted in the significant enrichment of (E)-resveratrol and several structurally related polyphenols. These secondary metabolites were subsequently identified by RP-HPLC and ?LC-ESI ion trap MS/MS methods. The developed MISPE protocol employed low volumes of environmentally benign solvents selected according to the Green Chemistry principles, and resulted in the recovery of 99% of the total (E)-resveratrol present. These results further demonstrate the potential of generic protocols for the analysis of target compound with health beneficial properties within the food and nutraceutical industries using tailor-made MIPs. PMID:23871560

  9. Evaluation of single-walled carbon nanohorns as sorbent in dispersive micro solid-phase extraction

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez-Soto, Juan Manuel; Cardenas, Soledad [Department of Analytical Chemistry, Institute of Fine Chemistry and Nanochemistry, Marie Curie Building, Campus de Rabanales, University of Cordoba, 14071 Cordoba (Spain); Valcarcel, Miguel, E-mail: qa1meobj@uco.es [Department of Analytical Chemistry, Institute of Fine Chemistry and Nanochemistry, Marie Curie Building, Campus de Rabanales, University of Cordoba, 14071 Cordoba (Spain)

    2012-02-10

    Highlights: Black-Right-Pointing-Pointer The potential of single walled carbon nanohorns in dispersive solid phase microextraction has been evaluated. Black-Right-Pointing-Pointer The method was characterized for the extraction of PAHs from waters. Black-Right-Pointing-Pointer Single walled carbon nanohorns were better extractant than carbon nanotubes and carbon nanocones. Black-Right-Pointing-Pointer The limits of detection were adequate for the target analytes in environmental waters. - Abstract: A new dispersive micro solid-phase extraction method which uses single-walled carbon nanohorns (SWNHs) as sorbent is proposed. The procedure combines the excellent sorbent properties of the nanoparticles with the efficiency of the dispersion of the material in the sample matrix. Under these conditions, the interaction with the analytes is maximized. The determination of polycyclic aromatic hydrocarbons was selected as model analytical problem. Two dispersion strategies were evaluated, being the functionalization via microwave irradiation better than the use of a surfactant. The extraction was accomplished by adding 1 mL of oxidized SWHNs (o-SWNHs) dispersion to 10 mL of water sample. After extraction, the mixture was passed through a disposable Nylon filter were the nanoparticles enriched with the PAHs were retained. The elution was carried out with 100 {mu}L of hexane. The limits of detection achieved were between 30 and 60 ng L{sup -1} with a precision (as repeatability) better than 12.5%. The recoveries obtained for the analytes in three different water samples were acceptable in all instances. The performance of o-SWNHs was favourably compared with that provided by carboxylated single-walled carbon nanotubes and thermally treated carbon nanocones.

  10. Evaluation of single-walled carbon nanohorns as sorbent in dispersive micro solid-phase extraction

    International Nuclear Information System (INIS)

    Highlights: ? The potential of single walled carbon nanohorns in dispersive solid phase microextraction has been evaluated. ? The method was characterized for the extraction of PAHs from waters. ? Single walled carbon nanohorns were better extractant than carbon nanotubes and carbon nanocones. ? The limits of detection were adequate for the target analytes in environmental waters. - Abstract: A new dispersive micro solid-phase extraction method which uses single-walled carbon nanohorns (SWNHs) as sorbent is proposed. The procedure combines the excellent sorbent properties of the nanoparticles with the efficiency of the dispersion of the material in the sample matrix. Under these conditions, the interaction with the analytes is maximized. The determination of polycyclic aromatic hydrocarbons was selected as model analytical problem. Two dispersion strategies were evaluated, being the functionalization via microwave irradiation better than the use of a surfactant. The extraction was accomplished by adding 1 mL of oxidized SWHNs (o-SWNHs) dispersion to 10 mL of water sample. After extraction, the mixture was passed through a disposable Nylon filter were the nanoparticles enriched with the PAHs were retained. The elution was carried out with 100 ?L of hexane. The limits of detection achieved were between 30 and 60 ng L?1 with a precision (as repeatability) better than 12.5%. The recoveries obtained for the analytes in three different water samples wehree different water samples were acceptable in all instances. The performance of o-SWNHs was favourably compared with that provided by carboxylated single-walled carbon nanotubes and thermally treated carbon nanocones.

  11. 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.

  12. 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 100mg of the adsorbent. Furthermore, the fast separation time (less than 10min) 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 0.1-50ngmL(-1) with low detection limit of 0.03ngmL(-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. PMID:25804513

  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

    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...

  14. Determination of additives in cosmetics by supercritical fluid extraction on-line headspace solid-phase microextraction combined with gas chromatography-mass spectrometry.

    Science.gov (United States)

    Yang, Tzung-Jie; Tsai, Feng-Jie; Chen, Chung-Yu; Yang, Thomas Ching-Cherng; Lee, Maw-Rong

    2010-06-01

    A new hyphenated technique couples supercritical fluid extraction in situ derivatization and on-line headspace solid-phase microextraction to gas chromatography-mass spectrometry (SFE in situ derivatization on-line HS-SPME-GC-MS) for the determination of paraben preservatives and polyphenolic antioxidants in cosmetics. The preservatives and antioxidants were extracted from the cosmetic matrices with supercritical carbon dioxide at a pressure of 13,840 kPa. The supercritical fluid extraction was performed at 55 degrees C for 10 min of static extraction then 15 min of dynamic extraction. The extractant subsequently was derivatized in situ with the silylation reagent N,O-bis(trimethylsilyl)trifluoroacetamide with 0.1% trimethylchlorosilane. The product was then adsorbed on a polyacrylate solid-phase microextraction (SPME) fiber in the headspace. Sea sand was used as a dispersive material in the SFE step. The analytical linear ranges for the preservatives and antioxidants were found to be from 10 to 1000 ng g(-1) with RSD values below 7.8%. The detection limits ranged from 0.5 to 8.3 ng g(-1). These results are better than those obtained by using only SPME or SFE for trace preservatives and antioxidants analysis in cosmetic matrices. The new method was successfully utilized to determine the amounts of preservatives and antioxidants in real cosmetics without the need for tedious pretreatments. PMID:20493297

  15. Determination of chloroacetic acids in drinking water using suppressed ion chromatography with solid-phase extraction.

    Science.gov (United States)

    Yoshikawa, Kenji; Soda, Yuko; Sakuragawa, Akio

    2009-12-01

    Suppressed ion chromatography with a conductivity detector was developed for the determination of trace amounts of underivatized chloroacetic acids (CAAs). When sodium carbonate and methanol were used as a mobile phase, the simultaneous determination of each CAA took approximately 25 min. The linearity, reproducibility and detection limits were determined for the proposed method. For the solid-phase extraction step, the effects of the pH of the sample solution, sample volume and the eluting agent were tested. Under the optimized extracting conditions, the average recoveries for CAAs spiked in tap water were 83-107%, with an optimal preconcentration factor of 20. The reproducibility of recovery rate for CAAs was 1.2-3.8%, based upon 6 repetitions of the recovery experiments. PMID:20009341

  16. Solid phase extraction of 22 drugs of interest in the forensic toxicology field

    Directory of Open Access Journals (Sweden)

    Mélinda Mancebo

    2008-01-01

    Full Text Available Many solid phase extraction columns which are dedicated to the extraction of various drugs associated with their specific protocols are proposed to the analyst. We have optimised a one stage procedure for the extraction from whole blood of acidic, neutral and basic drugs. Each step of the protocol has been optimised so as to obtain the best extraction recovery. The analysis of the extracts (identification and quantification has been realised with the help of High Performance Liquid Chromatography system coupled with a Diode Array Detector (HPLC-DAD. The SPE Evolute ABN column (Acid Base Neutral by Argonaut is the column which does extract the more and the best the different analysed components among all the columns which have been tested. Oasis HLB column (Hydrophilic Lipophilic Balance by Waters also allows the extraction of the whole list of active principles studied but with lower recoveries. The other columns studied (sold by Varian and Phenomenex presented insufficient results for this project. In the last step of the work we checked if the results did fit to the forensic toxicology purpose; detection and quantification limits have been compared to therapeutic and toxic concentrations usually found in forensic toxicology. Implementing this new procedure allowed us to create a method of comprehensive screening of drugs frequently implicated in forensic toxicology.

  17. 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.

  18. 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 assessuse 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

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

    Directory of Open Access Journals (Sweden)

    LukeRemage-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.

  20. Determination of urinary metabolites of alkyl cellosolves by solid phase extraction and GC/FID.

    Science.gov (United States)

    Choi, Hong Soon; Park, Jun Ho; Song, Jae Seok; Cho, Yong Bong

    2004-07-01

    Alkyl cellosolves include ethylene glycol monomethylether, ethylene glycol monoethylether, ethylene glycol monobuthylether. And their urine metabolites are methoxyacetic acid, ethoxyacetic acid and butoxyacetic acid. The current analytical method for urinary alkoxyacetic acid is liquid-liquid phase extraction. But the liquid-liquid phase extraction method needs a more complex pre-treatment process and has a low recovery rate. We determined the appropriate extraction solvent and its flow rate. We also evaluated the non-absorptive rate and recovery rate according to particle size. Finally we developed a convenient solid phase extraction method for the analysis of urine cellosolve metabolites. As a result, the recovery rates for methoxyacetic acid, ethoxyacetic acid and butoxyacetic acid were 100.4 +/- 1.6%, 100.2 +/- 1.8% and 100.7 +/- 10.0% respectively, when acetone was used as the extraction solution. The most appropriate flow rate was 0.1 ml/min. At a particle size of 140-200 mesh, non-absorption percentages for methoxyacetic acid, ethoxyacetic acid, butoxyacetic acid were 3.2 +/- 0.3%, 1.0 +/- 0.1% and 1.1 +/- 0.1%, and the recovery rates according to particle size were similar. Further evaluation of the recovery rate and non-absorptive rate according to the mini column shape, stationary phase and recovery rate with various extracting solutions is required. PMID:15308824

  1. Solid phase gene extraction isolates mRNA at high spatial and temporal resolution.

    Science.gov (United States)

    Scherp, Peter; Hasenstein, Karl H

    2008-08-01

    Rapid, localized changes in gene expression require mRNA extraction at high temporal and spatial resolution. Current small-scale mRNA extractions depend on the removal of the cells/tissue from an organism or preserved specimens. What these methods have in common is that they are destructive and do not distinguish between genomic DNA and RNA. Therefore, extracted (m)RNA is typically contaminated by extracted cytoplasm, nuclear DNA, or other compounds, and the required purification leads to loss of especially low-abundant mRNA. The need to repeatedly remove mRNA from living material has led to the development of solid phase gene extraction (SPGE). SPGE sampling can be achieved using gene-specific or generic sequences and is not species-specific. Here we demonstrate the versatility and validity of this novel RNA extraction by simultaneously profiling nanos and bicoid mRNA in individual Drosophila eggs. The SPGE technique detects previously described distribution profiles of nanos and bicoid. Its low impact is underscored by the normal development of repeatedly sampled eggs. In our study, quantification of actin mRNA in germinating flax seeds linked gene expression to distinct developmental processes. These data demonstrate the universality of SPGE as a simple generic, analytical, and diagnostic procedure. PMID:18687066

  2. Headspace Solid Phase Microextraction in Pesticide Residues Analysis:1. Optimisation of Extraction Conditions

    Directory of Open Access Journals (Sweden)

    Rada ?urovi?

    2007-01-01

    Full Text Available The method of headspace solid phase microextraction (HS/SPME was successfully used in a simultaneous multicomponent analysis of hexachlorobenzene (HCB, tefluthrin, heptachlor, aldrin, chlorpyrifos, fenthion and bifenthrin in aqueous medium. Measurementswere performed using a nonpolar polydimethyl siloxane (PDMS fiber. Detection and quantification were done by gas chromatography/mass spectrometry (GC/MS.Optimal conditions for HS/SPME were determined both by performing extraction at different temperatures and examining extraction time profiles at constant temperature. Optimal extraction temperature for each pesticide studied was determined as follows: 60°C for HCB and for heptachlor, 80°C for aldrin and for chlorpyrifos, fenthion and tefluthrin, and temperature exceeding 80°C for bifenthrin. For the pesticide mixture studied, 60°C was identified as the optimum extraction temperature.Based on the time profiles obtained, it was confirmed that satisfactory extraction sensitivity can be obtained even for extraction times shorter than the time required to reach a sorption equilibrium. This conclusion was confirmed by linear concentration profiles obtained for the following ranges: 0.05-10 ng/ml (HCB, 0.05-25 ng/ml (tefluthrin, 0.05-40 ng/ml (heptachlor, 0.05-40 ng/ml (aldrin, 0.05-25 ng/ml (chlorpyrifos, 0.05-25 ng/ml (fenthionand 0.05-25 ng/ml (bifenthrin.Relative standard deviation (RSD values for triplicate measurements did not exceed 15%.

  3. 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)

  4. 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.

    1354-13-01

    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.

  5. 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 a 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.

  6. 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.

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

    Science.gov (United States)

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

    2015-10-01

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

  8. Headspace Solid Phase Micro Extraction Gas Chromatographic Determination of Fenthion in Human Serum

    Directory of Open Access Journals (Sweden)

    Kyriaki Machera

    2008-05-01

    Full Text Available A simple and effective analytical procedure was developed for the determination of fenthion residues in human serum samples. The sample treatment was performed using the headspace solid-phase micro extraction with polyacrylate fiber, which has the advantage to require low amount of serum (1 mL without tedious pre-treatment. The quantification of fenthion was carried out by gas chromatography-mass spectrometry and the recoveries ranged from 79 to 104% at two spiking levels for 6 replicates. Detection and quantification limits were calculated as 1.51 and 4.54 ng/mL of serum respectively. Two fenthion metabolites − fenoxon and fenthion–sulfoxide − were also identified.

  9. 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.

  10. Solid phase extraction of trans-resveratrol from wines for HPLC analysis.

    Science.gov (United States)

    Mattivi, F

    1993-06-01

    Some recent studies have put forward the hypothesis that the presence of trans-resveratrol (trans-3,5,4'-trihydroxystilbene) in red wine may be related to some of its therapeutic properties. A fundamental step in view of this evaluation is the development of a method for the quick, accurate and precise analysis of this compound. Sample enrichment and purification can be obtained by solid-phase extraction using reverse-phase C18 cartridges. HPLC analysis carried out by means of a photodiode-array detector, with an internal standard method, allows the detection of up to 10 micrograms/L in wine, with a linear range between 0.6 and 300 ng injected and a precision of 3.3%. The results of the first analyses show that the concentrations of trans-resveratrol in wines might be much higher than so far reported in the literature. PMID:8328217

  11. Solid Phase Extraction (SPE) of REE's and uranium using sequestered resin

    International Nuclear Information System (INIS)

    A novel resin has been designed and developed for the pre-concentration and separation of trace amounts of rare earth elements (REE's) from uranium containing aqueous effluent by solid phase extraction technique. Determinations of Gadolinium (Gd) and Uranium (U) have been carried out by ICP-AES. Experiments were carried out using both batch and column techniques. Parameters such as equilibration rate, effect of concentration on sorption and desorption of metal ions have been studied. The maximum separation factor capacities for Gd and U were found to be 0.98 at pH 1.5 for Gd and same for U at pH 1.00 respectively when contacted originally 20 ppm Gadolinium and 10 ppm Uranium containing simulated solution. The designed sequestered resin was reusable even after 10 cycles

  12. Development of magnetic micro-solid phase extraction for analysis of phthalate esters in packaged food.

    Science.gov (United States)

    Makkliang, Fonthip; Kanatharana, Proespichaya; Thavarungkul, Panote; Thammakhet, Chongdee

    2015-01-01

    A novel, simple and low cost magnetic multi-walled carbon nanotubes-poly (vinyl alcohol) cryogel-micro-solid phase extraction (magnetic-MWCNTs-PVA cryogel-?-SPE) sorbent was synthesized by incorporating magnetic particles and MWCNTs into a PVA cryogel. The magnetic-MWCNTs-PVA cryogel-?-SPE sorbent developed, with a large surface area and macro-porous structure, provided good sorbent-to-sorbent reproducibility (%RSDplastic bags were found in the range 0.04-0.15 ?g mL(-1) and 0.03-0.20 ?g mL(-1), respectively, but only DEHP was found in clear chicken soup samples in the range 0.02-0.07 ?g mL(-1). PMID:25053056

  13. Solid phase extraction for sample preparation in trace analysis of ionogenic compounds by capillary isotachophoresis

    International Nuclear Information System (INIS)

    Various sorbents recommended for solid phase extraction (SPE) in sample preparation procedures were studied for use in combination with capillary isotachophoresis (ITP). They were very efficient in achieving trace concentration levels (low ppb, i.e., low parts per 109) for different types of ITP analytes present in environmental and biological matrices. A macroporous carbon sorbent was convenient for sample preparation in ITP analysis of short chain fatty acids (C4-C9) in drinking water. Chelating sorbents based on hydroxyalkyl methacrylate matrix with salicylate, thioglycolate and 8-hydroxyquinolinate functionalities were found to be very suitable for preconcentration of heavy metals with an inherent sample clean-up. An octadecyl-bonded silica sorbent enabled in ITP a photometric detection of ?-aminobutyrate (labeled with a 2,4,6-trinitrophenyl group) at concentrations considerably lower than required for the determination of this amino acid in cerebrospinal fluid (?5*10-8 mol/l). (author) 34 refs.; 3 figs.; 1 tab

  14. 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.

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

    Science.gov (United States)

    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 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. PMID:25277104

  16. Solid-Phase Extraction and Spectrophotometric Determination of Mercury with 6-Mercaptopurine in Environmental Samples

    International Nuclear Information System (INIS)

    A highly selective, sensitive and rapid method for the determination of trace amounts of inorganic mercury based on the reaction of Hg (2) with 6-mercaptopurine and the solid phase extraction of the complex on C18 membrane disks was developed. The 6-mercaptopurine selectively reacts with Hg (2) to form a complex in the pH range of 5-8. This complex was preconcentrated by solid phase extraction with C18 disks. An enrichment factor of 100 was achieved. The molar absorptivity of the complex is 0.26 x10-6 L. mol-1. cm-1 measured at 315 nm. The Beer's law is obeyed in the concentration range of 0.002 - 0.048 ?g mL-1. The relative standard deviation for eleven-replicated measurement of 0.04 ?g mL-1 is 1.5 %. The detection limit is 0.001 ?g mL-1 in the water samples. The advantage of the method is that the determination of Hg (2) is free from interference of almost all the cations and anions found in environment and wastewater samples. The determination of Hg (2) in water samples of different origins and marine sediment were carried out by the present method and cold vapor atomic absorption spectrometry (CVAAS). Also the method's accuracy was investigated by using SRM 2709. The obtained results by the present procedure were in good agreement with those of the CVAAS and certified value, so that the applicability of the proposed method was confirmed for the real samples for the real samples

  17. Optimization of Solid Phase Micro-Extraction (SPME for Monitoring Occupational Exposure to Ethyl Benzene

    Directory of Open Access Journals (Sweden)

    H Heidari

    2012-05-01

    Full Text Available

    Background and Objectives: Analytical methods for volatile organic compounds (VOCs in different samples need extraction of compounds, by applying hazardous solvents. Solid phase micro-extraction (SPME is a solvent-free equilibrium extraction method, in which proper calibration can allow quantitative determinations of VOCs at a very good sensitivity without the use of any organic solvent. VOCs are generally present in urine only at trace levels, therefore, a sensitive procedure is needed for their trace determinations. Throughout this study, headspace solid phase micro-extraction (HS-SPME was followed by GC-FID for ethyl benzene in spiked urine was optimized.

    Methods: In this study, the parameters influencing SPME and gas chromatography of ethyl benzene, including extraction time, temperature, desorption temperature, desorption time, salt addition, sample pH, sample volume and sample agitation were investigated.

    Results: Extraction procedure was performed at 30°C for 6 min, using 0.2 gml-1 of NaCl in the sample solution. The sample volume and sample pH were optimized at 5 ml and 7 (neutral pH, respectively. Desorption of the ethyl benzene was carried out for 60 sec. at 250°C. The method was also validated with three different spiked urine samples and illustrated an appropriate reproducibility over six consecutive days as well as six within-day experiments. During this investigation, parameters of accuracy, linearity, and detection limits of the procedure were also evaluated.

    Conclusion: The developed method of HS- SPME-GC-FID proved to be a simple, convenient, and practical procedure, and was successfully used for measuring of ethyl benzene in spiked urine.

  18. Solid phase microextraction and stir bar sorptive extraction for organotin compounds - a comparison (P9)

    International Nuclear Information System (INIS)

    Full text: Organotin compounds have been largely used in agricultural and industrial applications. Hyphenated techniques were developed for the sensitive and selective determination of such species. For this task GC has been coupled with atomic emission detection. Derivatization to transform the Sn-compounds into sufficiently volatile compounds was necessary and carried out using sodium tetrapropylborate. For sample preparation the application of solid phase microextraction (SPME) give recent advances in comparison to classical liquid-liquid extraction (LEE). A problem in the usage of SPME exists however in the small volume of the PDMS coating for enrichment the analytes. For improvement of both sample enrichment and extraction of the organotin compounds stir bar sorptive extraction (SBSE) was applied. It base on the application of stir bars coated with PDMS. Here the extraction yield is substantially higher. Aim of this study was to compare the capabilities of GC-AED in combination with SPME and SBSE. After optimization of the experimental parameters it was possible to reach detection limits in the pg / 1 - level. A comparison of both methods shows the expected results. By application of SBSE it was possible to increase the detection limits one order of magnitude. With SPME the reproducibility of the analytical results (in the 1 ng / 1 concentration range) was found to be between 10 and 15 %, it could be enhanced to 5-8 % by application of SBSE. These low limits of detection and the good reproducibility allowed the determination of organotin compounds according required regulations. Ref. 1 (author)

  19. Chemically functionalized ? alumina with alizarin red-S for selective complexion solid phase extraction of Pb (II), Ag(I) and determination by flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Complete text of publication follows. A new and efficient solid phase extraction method is described for the preconcentration of Pb(II), Ag(I). ? Alumina was firstly functionalized with sodium dodecyle sulfate and then adding the alizarin red-S solution in ethanol, the solid phase was prepared to adsorb trace heavy metals in the samples. The metal sorption properties of modified alumina were studied towards Pb(II), Ag (I). For batch method, the optimum pH was 7 and the contact times to rich the equilibrium were about 15 min. Various parameter such as amount of adsorbent, ligand, surfactant, eluent type and volume, flow rate of sample solution, volume of the sample solution and matrix interference effect on the retention of the metal ions have been studied. The linear range was 100-1500, and 300-3000 ng mL-1 for lead and silver, respectively. The preconcentration factor 35 and 32 for lead and silver, respectively. The limit of detection was 45 and 150 ng mL-1 for lead and silver respectively. This method was successfully applied for separation and determination of Pb(II), Ag (I) in some real samples.

  20. Improving the solid-phase extraction of "quat" pesticides from water samples. Removal of interferences.

    Science.gov (United States)

    Ibáñez, M; Picó, Y; Mañes, J

    1998-10-01

    A novel strategy, based on the addition of a cationic surfactant, for preventing the interferences associated with a diminution in the efficacy of solid-phase extraction (SPE) with silica cartridges of diquat, paraquat and difenzoquat in water is developed. Conditions for extraction are optimised with respect to pH, cationic surfactant and its concentration. Humic acids, anionic surfactants, inorganic salts and other organic contaminants like pesticides, phenols, polycyclic aromatic hydrocarbons and polychlorinated biphenyls produce the studied interferences. The best performance is shown in the improvement of the "quats" recovery from waters with high levels of humic acids and anionic surfactants (recovery is increased from ca. 30% to more than 80%). Unfortunately, the strong interference from inorganic salts remains. The presence in the water sample of other organic contaminants only affected the extraction efficiency of difenzoquat at high concentrations (more than 1 mg/l). Analytic utility is illustrated by selective measurements of the three herbicides, in real water samples. Overall, the results show that in spite of its drawbacks, SPE is a useful technique that allows the detection and quantification of the "quats" at limits below 100 ng/l as established by the European Union. PMID:9818401

  1. 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)

  2. PHARMACOKINETIC STUDY OF RISPERIDONE: APPLICATION OF A HPLC METHOD WITH SOLID PHASE EXTRACTION

    Directory of Open Access Journals (Sweden)

    PABLO TORRES V

    2011-01-01

    Full Text Available A new, simplified solid phase extraction procedure for the determination of risperidone and 9-hydroxyrisperidone in human plasma has been developed. This method involves the use of an optimized extraction protocol developed in Waters OASIS® HLB 30mg 1cc extraction columns using 1 mL of human serum. Separation was performed by HPLC using a Waters XTerra RP-18 (5 µm, 150x4,6 mm column with a mobile phase consisting in acetonitrile - potassium dihydrogen phosphate 50 mM pH 3.4 (27/73. UV detection at 278 nm was used to quantify analytes, encountering good linearity (r² > 0.999 in the 2-100 ng/mL concentration range. The mean recovery was 92.4 % and 92.8 % for risperidone and 9-hydroxyrisperidone respectively, with an intraday - interday precision below 7%, and accuracy below 115 %. The method has been successfully applied in pharmacokinetic studies that require a large sample number.

  3. PHARMACOKINETIC STUDY OF RISPERIDONE: APPLICATION OF A HPLC METHOD WITH SOLID PHASE EXTRACTION

    Scientific Electronic Library Online (English)

    PABLO, TORRES V; M. JACQUELINE, SEPÚLVEDA C; CARLOS, VON PLESSING R.

    Full Text Available A new, simplified solid phase extraction procedure for the determination of risperidone and 9-hydroxyrisperidone in human plasma has been developed. This method involves the use of an optimized extraction protocol developed in Waters OASIS® HLB 30mg 1cc extraction columns using 1 mL of human serum. [...] Separation was performed by HPLC using a Waters XTerra RP-18 (5 µm, 150x4,6 mm) column with a mobile phase consisting in acetonitrile - potassium dihydrogen phosphate 50 mM pH 3.4 (27/73). UV detection at 278 nm was used to quantify analytes, encountering good linearity (r² > 0.999) in the 2-100 ng/mL concentration range. The mean recovery was 92.4 % and 92.8 % for risperidone and 9-hydroxyrisperidone respectively, with an intraday - interday precision below 7%, and accuracy below 115 %. The method has been successfully applied in pharmacokinetic studies that require a large sample number.

  4. Cyclodextrin polymer/Fe3O4 nanocomposites as solid phase extraction material coupled with UV-vis spectrometry for the analysis of rutin

    Science.gov (United States)

    Gong, Aiqin; Ping, Wenhui; Wang, Jue; Zhu, Xiashi

    2014-03-01

    In this paper, carboxymethyl-hydroxypropyl-?-cyclodextrin polymer modified magnetic particles Fe3O4 (CM-HP-?-CDCP-MNPs) were prepared and applied to magnetic solid phase extraction of rutin combined with UV-visible spectrometry detection. The synthesized magnetic particles were characterized by element analysis, Fourier transform infrared spectra, thermal gravimetric analysis, and transmission electron microscopy. Several variables affecting the extraction and desorption of rutin such as pH, the amount of adsorbent, the type and volume of eluent, extraction and desorption time, and temperature were investigated. The maximum adsorption capacity was 67.0 mg g-1 for rutin with the equilibrium time of 30 min at room temperature, and the adsorbent could be reused for 10 times. A calibration curve was linear in the range of 0.05-8.00 ?g mL-1 with a relative standard deviation of 2.9% (n = 5, c = 4.0 ?g mL-1). The limit of detection was 7.0 ng mL-1. The interaction mechanism between the adsorbent and rutin was also studied. Feasibility of this method was validated by the analysis of rutin tablets and lotus plumule.

  5. 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.

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

    Science.gov (United States)

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

    2007-01-01

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

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

    Science.gov (United States)

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

    2007-01-01

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

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

    Science.gov (United States)

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

    2015-05-01

    In this work, molecularly imprinted magnetic carbon nanotubes (MCNTs@MIPs) was prepared with surface imprinting technique for extraction of levofloxacin in serum samples. The preparation of molecularly imprinted polymers (MIPs) used levofloxacin as template, methacrylic acid as functional monomer, and ethylene glycol dimethacrylate as cross-linker, and the magnetic carbon nanotubes (MCNTs) was synthesized by solvothermal method. The prepared polymers not only can be separated and collected easily by an external magnetic, but also exhibited high specific surface area and high selectivity to template molecules. Kinetic adsorption and static adsorption capacity investigations indicated that the synthesized MCNTs@MIPs had excellent recognition towards levofloxacin. Furthermore, magnetic solid phase extraction (MSPE) using the prepared MCNTs@MIPs as sorbent was then investigated, and an efficient sample cleanup was obtained with recoveries ranged from 78.7?±?4.8?% to 83.4?±?4.1%. In addition, several parameters, including the pH of samples, the amount of MCNTs@MIPs, the adsorption and desorption times, and the eluent, were investigated to obtain optimal extraction efficiency. Under the optimal extraction conditions, the stability of the polymer was also evaluated, and the average recovery reduced less than 7.6% after 5 cycles. MCNTs@MIPs successfully applied in the preconcentration and determination of levofloxacin in serum sample suggested that the MSPE method based on the novel polymers could be a promising alternative for selective and efficient extraction of trace amounts of pharmaceutical substances in bio-matrix samples. Copyright © 2015 John Wiley & Sons, Ltd. PMID:25732346

  9. 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)

  10. 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

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

    Science.gov (United States)

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

  12. 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

  13. Solid Phase Extraction for Monitoring of Occupational Exposure to Cr (III

    Directory of Open Access Journals (Sweden)

    S.J. Shahtaheri

    2007-01-01

    Full Text Available Chromium is an important constituent widely used in different industrial processes for production of various synthetic materials. For evaluation of workers’ exposure to trace toxic metal of Cr (III, 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 analysis. The use of solid-phase extraction (SPE has grown and is a fertile technique of sample preparation as it provides better results than those produced by liquid-liquid extraction (LLE. SPE using mini columns filled with XAD-4 resin was optimized regarding to sample pH, ligand concentration, loading flow rate, elution solvent, sample volume, elution volume, amount of resins, and sample matrix interferences. Chromium was retained on solid sorbent and was eluted with 2 M HNO3 followed by simple determination of analytes by using flame atomic absorption spectrometery. Obtained recoveries of metal ion were more than 92%. The optimized procedure was also validated with three different pools of spiked urine samples and showed a good reproducibility over six consecutive days as well as six within-day experiments. Through this study, suitable results were obtained for relative standard deviation, therefore, it is concluded that, this optimized method can be considered to be successful in simplifying sample preparation for trace residue analysis of Cr in different matrices for evaluation of occupational and environmental exposures. To evaluate occupational exposure to chromium, 16 urine samples were taken, prepared, and analyzed based on optimized procedure.

  14. Magnetic solid phase extraction and gas chromatography-mass spectrometrical analysis of sixteen polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Cai, Ying; Yan, Zhihong; NguyenVan, Manh; Wang, Lijia; Cai, Qingyun

    2015-08-01

    Fluorenyl functionalized superparamagnetic core/shell magnetic nanoparticles (MNPs, Fe3O4@SiO2@Flu) were prepared and characterized by transmission electron microscope, X-ray diffraction and infrared spectroscopy. The MNPs having an average diameter of 200nm were then used as solid-phase extraction sorbent for the determination of 16 priority pollutants polycyclic aromatic hydrocarbons (PAHs) in water samples designated by United States Environmental Protection Agency (U.S. EPA). The main influencing parameters, including sorbent amount, desorption solvent, sample volume and extraction time were optimized. Analyses were performed on gas chromatography-mass spectrometry (GC-MS) using selected ion monitoring (SIM) mode. Method validation proved the feasibility of the developed sorbents for the quantitation of the investigated analytes at trace levels. Limit of detection ranging from 0.5 to 4.0ng/L were obtained. The repeatability was investigated by evaluating the intra- and inter-day precisions with relative standard deviations (RSDs) lower than 13.1%. Finally, the proposed method was successfully applied for the determination of PAHs in water samples with the recoveries in the range of 96.0-106.7%. PMID:26122856

  15. Preconcentration of Lead in Sugar Samples by Solid Phase Extraction and Its Determination by Flame Atomic Absorption Spectrometry

    OpenAIRE

    Saied Saeed Hosseiny Davarani; Neda Sheijooni-Fumani; Amin Morteza Najarian; Mohammad-Ali Tabatabaei; Siavash Vahidi

    2011-01-01

    A simple and sensitive solid phase extraction utilizing C18 filled cartridges incorporated with dithizone for preconcentration of lead and its subsequent determination by flame atomic absorption spectrometry (FAAS) was developed. Several parameters such as type, concentration and volume of eluent, pH of the sample solution, flow rate of extraction and volume of the sample were evaluated. The effect of a variety of ions on preconcentration and recovery was also investigated. At pH = 7.4 and 1....

  16. 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.

    2232-22-01

    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.

  17. [Determination of cholesterol in drainage oil by solid phase extraction-gas chromatography-mass spectrometry].

    Science.gov (United States)

    Zhou, Yongsheng; Luo, Shiping; Kong, Yong

    2012-02-01

    An effective method was developed for the determination of cholesterol in drainage oil by solid phase extraction-gas chromatography-mass spectrometry (SPE-GC-MS). Firstly, the samples were purified by SPE on a column packed with silica. An extraction yield of 97% was obtained when a 20 mL of ethyl ether/n-hexane mixture (0.6: 99.4, v/v) was used for washing the SPE column, and 10 mL of the same solvent mixture (15: 85, v/v) for desorbing cholesterol from the SPE column. Then the final extract was determined by GC-MS with electron impact ion source. The cholesterol was characterized according to retention time and characteristic fragments (m/z 213, 275, 301, 368, 386), and was quantitatively determined by external standard method in selected ion monitoring mode. The fragment of m/z 386 was selected as the target ion, and m/z 213 and m/z 275 were used as the reference ions. The average recovery was from 91.7% to 101%, and the relative standard deviations (RSDs) were below 6%, and the detection limit was 0.01 mg/L. A good linearity was obtained in the cholesterol concentration range of 0.24 - 6.0 mg/L with the correlation coefficient of 0.999 6. The proposed method can be used to determine the cholesterol content in oil accurately, and the detection result can be one of the criteria judging the existence of drainage oil in edible oil. PMID:22679838

  18. Preparation and evaluation of molecularly imprinted polymer of olivetol for solid phase extraction.

    Science.gov (United States)

    Jin, Yafeng; Chen, Na; Liu, Runqiang; Chen, Jun; Bai, Lianyang; Zhang, Yuping

    2013-06-01

    Molecularly imprinted polymer (MIP) was synthesized by bulk polymerization, using olivetol as template molecule, methyl acrylic acid (MAA) as monomer, ethylene glycol dimethacrylate (EDMA) as crosslinker, toluene and dodecanol as solvents. The resulted MIP was characterized by the equilibrium binding experiments, scanning electron microscope (SEM) and Fourier transform infrared spectrometer (FTIR). The polymer was then applied to solid phase extraction (SPE) of olivetol from spiked wheat bran samples. From the equilibrium binding experiments, it was showed that MIP had a better recognizability for the template molecule. Scatchard analysis showed that MIP had specific adsorption to olivetol with two classes of binding sites. The high and low binding sites dissociation constants were 0.021 and 1.002 mmol/L. The corresponding maximum binding capacities were 18.74 and 135.9 micromol/g, respectively. Under the optimum condition of SPE, the recoveries of olivetol on MIP cartridge were in the range of 97.8% - 98.8%. The relative standard deviations (RSDs) were 2.8% -4.2%. The linearity range was between 0.1 and 100 mg/L. The limit of detection (S/N = 3) was 0.062 mg/L. MIP cartridge showed stronger selectivity, higher recovery and purified the sample more drastically compared with non-imprinted polymer (NIP) cartridge and commercial poly (styrene/divinyl-benzene) (PLS) cartridge. PMID:24063201

  19. 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)

  20. 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.

  1. Collecting peptide release from the brain using porous polymer monolith-based solid phase extraction capillaries.

    Science.gov (United States)

    Iannacone, Jamie M; Ren, Shifang; Hatcher, Nathan G; Sweedler, Jonathan V

    2009-07-01

    Porous polymer monolithic (PPM) columns are employed to collect and concentrate neuronal release from invertebrate and vertebrate model systems, prior to their characterization with mass spectrometry. The monoliths are fabricated in fused-silica capillaries from lauryl methacrylate (LMA) and ethylene glycol dimethacrylate (EDMA). The binding capacities for fluorescein and for fluorescently labeled peptides are on the order of nanomoles per millimeter of length of monolith material for a capillary with an inner diameter of 200 microm. To evaluate this strategy for collecting peptides from physiological solutions, angiotensin I and insulin in artificial seawater are loaded onto, and then released from, the monoliths after a desalination rinse, resulting in femtomole limits of detection via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Positioned in the extracellular media near Aplysia californica bag cell neurons, upon electrical stimulation, these LMA-EDMA monoliths are also used to collect and concentrate peptide release, with egg-laying hormones and acidic peptide detected. In addition, the collection of several known peptides secreted from chemically stimulated mouse brain slices demonstrates their ability to collect releasates from a variety of neuronal tissues. When compared to collection approaches using individual beads placed on brain slices, the PPM capillaries offer greater binding capacity. Moreover, they maintain higher spatial resolution, compared to the larger-volume, solid-phase extraction collection strategies. PMID:19485405

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

    Science.gov (United States)

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

    2014-12-01

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

  3. 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.

  4. 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

  5. Tandem Solid Phase Extraction for the Determination of Pharmaceuticals in Wastewater

    International Nuclear Information System (INIS)

    In this study, a simple and rapid tandem solid phase extraction (SPE) was developed for the analysis of seven pharmaceuticals (acetaminophen, caffeine, carbamazepine, diclofenac, naproxen, ibuprofen and metaprolol) in wastewater sample. The novel aspect of coupling SPE cartridge in tandem is the ability to simplify the SPE procedure (sample introduction step) as no single sorbent was able to retain and concentrate all selected compounds since these compounds are of different physicochemical properties. A tandem SPE cartridges using Oasis HLB and octadecyl bonded silica (C18) was found to be efficient with the advantages of minimizing sample volume and reducing analysis time. Using this approach, carbamazepine, diclofenac, naproxen and metaprolol were trapped in the Oasis HLB while acetaminophen, caffeine and ibuprofen were trapped in the second cartridge (C18). The instrumental limits of detection (LOD) ranged from 0.01 to 0.04 ?g/ L and satisfactory recoveries were obtained between 76 % to 104 %. The calibration curves were linear from 0.1 to 5.0 ?g/ mL, with correlation coefficients (R2) in the range of 0.995 to 0.999. The developed method was applied to the analysis of pharmaceuticals in wastewater samples. The amount of pharmaceuticals detected in wastewater samples varied from 0.4 to 24.5 mg/ L. (author)

  6. Identification and fingerprinting of biodiesel blends by solid phase extraction and gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    Interest in biodiesel as a replacement for petroleum diesel fuel is growing. In North America, biodiesels are produced by the methyl esterification of plant and animal triglycerides, resulting in complex mixtures composed of fatty acid methyl esters (FAMEs). It is important for both environmental forensic and remediation purposes to determine diesel and biodiesel origins, and the biodiesel content when it is blended with conventional petroleum diesel. This paper reported on a study that combined 2 methods to determine biodiesel levels in blended fuels. Micro-column fractionation of FAMEs involving solid phase extraction (SPE) was combined with gas chromatography-mass spectrometry (GC/MS) to achieve detailed chemical fingerprinting of blends, including the identification and quantification of individual aliphatic hydrocarbons, aromatic hydrocarbons, fatty acid alkyl esters, and free sterols. Fractionation of the fuel samples was optimized for separation of fatty acid esters, free sterols from petroleum hydrocarbons into 4 fractions, notably aliphatic, aromatic, fatty-acid ester and polar components. A sum of the FAME components was used to determine an unknown blend level in freshly-prepared samples. This study showed that this method has great potential for identifying biodiesel in diesel fuel blends and could form the basis of a method for biodiesel-contaminated environmental samples. 28 refs., 5 tabs., 4 figs.

  7. Dispersive micro solid-phase extraction for the rapid analysis of synthetic polycyclic musks using thermal desorption gas chromatography-mass spectrometry.

    Science.gov (United States)

    Chung, Wu-Hsun; Tzing, Shin-Hwa; Ding, Wang-Hsien

    2013-09-13

    A simple and solvent-free method for the rapid analysis of five synthetic polycyclic musks in water samples is described. The method involves the use of dispersive micro solid-phase extraction (D-?-SPE) coupled with direct thermal desorption (TD) gas chromatography-mass spectrometry (GC-MS) operating in the selected-ion-storage (SIS) mode. The parameters affecting the extraction efficiency of the target analytes from water sample and the thermal desorption conditions in the GC injection-port were optimized using a central composite design method. The optimal extraction conditions involved immersing 3.2mg of a typical octadecyl (C18) bonded silica adsorbent (i.e., ENVI-18) in a 10mL water sample. After extraction by vigorously shaking for 1.0min, the adsorbents were collected and dried on a filter. The adsorbents were transferred to a micro-vial, which was directly inserted into GC temperature-programmed injector, and the extracted target analytes were then thermally desorbed in the GC injection-port at 337°C for 3.8min. The limits of quantitation (LOQs) were determined to be 1.2-3.0ng/L. Precision, as indicated by relative standard deviations (RSDs), was less than 9% for both intra- and inter-day analysis. Accuracy, expressed as the mean extraction recovery, was between 74 and 90%. A preliminary analysis of the river water samples revealed that galaxolide (HHCB) and tonalide (AHTN) were the two most common synthetic polycyclic musks present. Using a standard addition method, their concentrations were determined to in the range from 11 to 140ng/L. PMID:23932027

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

    Science.gov (United States)

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

  9. [Application of molecularly imprinted solid phase extraction in the separation and determination of active constituents from natural compounds].

    Science.gov (United States)

    Chen, Fangfang; Shi, Yanping

    2013-07-01

    The active constituents of natural medicine resources are complicated and in low content, which are difficult to be extracted and separated by general methods. Molecularly imprinted polymers are functional porous materials with molecular-specific recognition sites to a particular target molecule. The molecularly imprinted solid phase extraction has been used as a sample preparation technique for the separation of active constituents from natural medicine resources. The target molecules in a mixture of chemical species can be recognized selectively. In this review, the applications of the molecularly imprinted solid phase extraction for the determination and separation of active constituents (e. g. flavonoids, polyphenols, alkaloids, organic acids, phenylpropanoids, terpenoids, etc. ) from natural compounds in recent years are summarized. PMID:24164030

  10. [Preparation and application of di(2-propylheptyl) phthalate molecularly imprinted solid-phase extraction sorbent].

    Science.gov (United States)

    Wei, Shoulian; Guo, Xiaojun; Yan, Zijun; Liu, Yong; Wang, Hongwu

    2014-05-01

    The molecular imprinted polymer (MIP) with high selectivity to di(2-propylheptyl) phthalate (DPHP) was synthesized by precipitation polymerization with dioctyl phthalate (DOP) as dummy template, methacrylic acid (MAA) as functional monomer and ethylene glycol dimethacrylate (EDMA) as cross-linker. The binding ability of the template and functional monomer was investigated by UV spectrometry. Compared with the functional monomer acrylic acid (AA), MAA showed stronger binding capacity to DOP and the best combination mole ratio of 6 : 1. The selective adsorption performance of MIP for DOP, DPHP, dimethyl phthalate (DMP) and dibutyl phthalate (DBP) was investigated using the prepared MIP as high performance liquid chromatographic column packing. It was found that the prepared MIP showed higher retention ability and selectivity for DPHP. Using the prepared MIP as a solid-phase extraction (SPE) sorbent (MISPE), the effects of the type and amount of washing solvent and elution solvents on the recovery of DPHP were investigated. After optimization of MISPE profile, the DPHP extraction recovery of 96.8% was obtained when the following procedures were applied to MISPE cartridge: conditioning with 2 mL methanol, loading with 1 mL methanol, washing with 1 mL methanol-water (1 : 9, v/v), eluting with 5 mL methanol-acetic acid (9:1, v/v). The recovery of DPHP on non-imprinted polymer (NIP) cartridge was only 52.9%. The developed MISPE-HPLC method was applied to determine the concentrations of DPHP in rabbit serum at different time points after oral administration. It was found that the maximal concentration (c(max)) and time (t(max)) were 5.88 microg/mL and 4 h, respectively. The recoveries of spiked DPHP in rabbit serum ranged from 90.0% to 92.0% with the relative standard deviations less than 5%. PMID:25185304

  11. Molecularly imprinted solid-phase extraction for rapid screening of mycophenolic acid in human plasma.

    Science.gov (United States)

    Yin, Junfa; Wang, Sumin; Yang, Guanqun; Yang, Gengliang; Chen, Yi

    2006-11-21

    A molecularly imprinted solid-phase extraction coupled with high performance liquid chromatography (MISPE-HPLC) method was developed for rapid screening of mycophenolic acid (MPA) in human plasma. MPA imprinted polymers (MPA-MIP) were synthesized and then tested for their performance both in organic and in aqueous solution. MPA was selectively trapped and preconcentrated on the MPA-MIP sorbent using different loading and washing conditions. The good selectivity of MPA-MIP enabled further clean-up of the interfering components in human plasma. For the proposed MISPE-HPLC method, the linearity between responses (peak area) and concentration was found over the range of 1-100microg/ml with a linear regression coefficient (R(2)) of 0.9989. The limit of detection (LOD) and theoretical limit of quantification (LOQ) for MPA in plasma were 0.10 and 0.32microg/ml, respectively. The precisions were 7.3, 3.5 and 4.7% RSD for intra-day assay and 9.2, 4.1 and 5.5% RSD for inter-day reproducibility, respectively, at three concentration levels of MPA in spiked plasma (1, 10 and 100microg/ml). Both recoveries for the extraction (more than 74%) and for the analytical method (more than 87%) were acceptable for screening MPA in plasma samples. Twelve-hour pharmacokinetic profile of MPA for a renal transplant recipient receiving chronic oral dosing of 500mg mycophenolate mofetil (MMF) was investigated. Results indicated that this method could be applied for therapeutic drug monitoring of mycophenolic acid in patient plasma. PMID:16891160

  12. Extraction and analysis of polycyclic aromatic hydrocarbons (PAHs) by solid phase micro-extraction/supercritical fluid chromatography (SPME/SFC)

    Energy Technology Data Exchange (ETDEWEB)

    Lesellier, E. [Institut Universitaire de Technologie, (LETIAM), 91 - Orsay (France)

    1999-05-01

    Solid phase micro-extraction (SPME) is a clean and simple pre-concentration method. Previously used for trace analysis of volatile compounds, the use of SPME was extended to non volatile molecules with the development of an SPME/HPLC interface. This new interface allows the extraction and the analysis of high molecular weight compounds found in aqueous samples. Since superficial fluid chromatography is particularly well suited for analysis of complex mixtures containing non volatile compounds, the feasibility of coupling SPME and SFC has been investigated and applied to PAHs. Several points have been studied: behavior of interface and of fiber to superficial fluid and high pressure required by the analytical method; kind of the compounds transfer from the fiber to the analytical column; relation between the nature of the fibers and the quantity of extracted compounds; effect of salt addition. The results show that the SPME/SFC technic may be used for extraction and analysis of PAHs, since the quantity of extracted compounds reach 30 %. (author) 17 refs.

  13. 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.

  14. 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...

  15. State-of-the-art in solid-phase extraction of biofluids (M10)

    International Nuclear Information System (INIS)

    Full text: A major drawback of many SPE protocols in bioanalytical LC is a rather unselective and/or time consuming clean-up procedure. In order to optimize SPE based sample processing with regard to selectivity and speed we investigated tailor-made SPE adorbents, distinct SPE column hardware as well as a novel software (ChromSword ADS, Merck KGaA) for LC(MS)-integrated SPE using column-switching. Restricted Access Materials (RAM) are one family of such special SPE column packing. RAMs are characterized in that they have a defined size-selective exclusion barrier and a non-adsorptive outer particle surface towards macromolecular matrix components (e.g. proteins, nucleic acids, polysaccharides). Low-molecular compounds (e.g. drugs) have free access to the binding centers and thus can be extracted and enriched prior to their analytical separation and MS detection. A RAM-SPE column (e.g. LiChrospher ADS, Merck KGaA, Germany) allows the direct, multiple injection and fractionation of crude, complex samples such as hemolyzed blood, plasma, serum, milk, saliva, urine, fermentation broth and cell-culture or tissue homogenate supernatant. In order to improve the selectivity, we extended this on-line sample clean-up protocol by coupling a reversed-phase modified RAM-SPE column with a second short column packed with a Molecularly Imprinted Polymeric (MIP) adsorbent. MIP-SPE adsorbents can be compared with immunoaffinity adsorbents. Besides selective/specific molecular recognition properties, these artificial antibodies exhibit a high stability with respect to pressure, pH, temperature as well as organic solvents. These innovative adsorbents are also attractive because of the ease, low-cost and high reproducibility of preparation. Using MIPS in combination with RAMs we developed a generic SPE platform and protocol, respectively, for highly selective clean-up of complex (bio)fluids. Finally, we succeeded in speeding up the RAM fractionation step (e.g. extraction of 50 pl of human plasma in less than 60 seconds) by applying an optimized column size and flow-rate, respectively. In conclusion, tailor-made SPE-column packing and hardware allow a robust and rugged operation of on-line (high speed) SPE-(LC)-MS(MS). Refs. 6 (author)

  16. / 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.

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

    Science.gov (United States)

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

    2015-05-01

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

  18. 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...

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

    DEFF Research Database (Denmark)

    Mysling, Simon; Palmisano, Giuseppe

    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% formic acid (defined as IP(2% FA) ZIC-HILIC SPE), 0.1% TFA and 1% TFA (defined as IP(0.1% TFA) and IP(1% TFA) ZIC-HILIC SPE) all containing 80% acetonitrile. Samples of increasing complexities, i.e., digests of single glycoproteins, a five-glycoprotein mixture, and depleted plasma, were used in the study. The presence of TFA in the mobile phase significantly improved the glycopeptide enrichment for all complexities, as evaluated by enhanced glycopeptide detection using MALDI-TOF MS and RP-LC-ESI-MS/MS, e.g., the glycopeptide ion signals were increased by up to 3.7-fold compared to IP(2% FA) conditions. The enhanced glycopeptide detection was promoted by a substantial depletion of nonglycosylated peptides, offering an almost complete isolation of IgG glycopeptides using a single SPE enrichment step and a reduction from 711 nonglycosylated peptides observed in the IP(2% FA) ZIC-HILIC SPE retained plasma fraction, to only 157 and 97 when 0.1% and 1% TFA was used in the mobile phase. In conclusion, this systematic study has shown that TFA-containing mobile phases increase glycopeptide enrichment efficiency considerably for a broad range of sample complexities when using ZIC-HILIC SPE.

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

    Science.gov (United States)

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

  1. Speciation of copper and manganese in milk by solid-phase extraction inductively coupled plasma-atomic emission spectrometry

    OpenAIRE

    MENTASTI, Edoardo; Bruzzoniti, Maria Concetta; ACETO, Maurizio; ABOLLINO, Ornella; SARZANINI, Corrado

    1998-01-01

    A speciation method was developed to study distribution of copper and manganese species in cow milk. The method is based upon solid-phase extraction of selective fractions of the analytes, followed by elution and determination by inductively coupled plasma-atomic emission spectrometry (ICP-AES), using it as a flow-injection detector. Fractions detected were cationic, anionic, neutral and casein-bound. A different behaviour is observed for the two metals.

  2. Polymer Microchips Integrating Solid Phase Extraction and High Performance Liquid Chromatography Using Reversed-Phase Polymethacrylate Monoliths

    OpenAIRE

    Liu, Jikun; Chen, C F; Tsao, C. W.; Chang, C.C.; Chu, C. C.; DeVoe, D. L.

    2009-01-01

    Polymer microfluidic chips employing in situ photopolymerized polymethacrylate monoliths for high performance liquid chromatography separations of peptides is described. The integrated chip design employs a 15 cm long separation column containing a reversed-phase polymethacrylate monolith as a stationary phase, with its front end seamlessly coupled to a 5 mm long methacrylate monolith which functions as a solid phase extraction (SPE) element for sample cleanup and enrichment, serving to incre...

  3. 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

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

    OpenAIRE

    Seyed Jamaleddin Shahtaheri; Farideh Golbabaei; Abolfazle Barkhordari; Abbas Rahimi–Froushani; Fateme Kargar

    2012-01-01

    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 extract...

  5. Determination of Tripdiolide in Root Extracts of Tripterygium wilfordii by Solid-phase Extraction and Reversed-phase High-performance Liquid Chromatography

    OpenAIRE

    Ma, Jun; Schmidt, Barbara M.; Poulev, Alexander; Raskin, Ilya

    2008-01-01

    Extracts of Tripterygium wilfordii Hook F. have been widely used in China to treat a variety of autoimmune and inflammatory diseases. The diterpenoids triptolide and tripdiolide are two major active components in the T. wilfordii ethyl acetate extract. An efficient solid-phase extraction and high-performance liquid chromatography (SPE-HPLC) method to measure triptolide content in the extract has been previously reported. However, a suitable means of tripdiolide quantification is not available...

  6. Determination of hexanal and heptanal in human urine using magnetic solid phase extraction coupled with in-situ derivatization by high performance liquid chromatography.

    Science.gov (United States)

    Liu, Jiu-Feng; Yuan, Bi-Feng; Feng, Yu-Qi

    2015-05-01

    In this study, magnetic solid phase extraction coupled with in-situ derivatization (MSPE-ISD) was established for the determination of hexanal and heptanal in human urine. 2,4-Dinitrophenylhydrazine (DNPH) was used as the derivatization reagent that was adsorbed onto the surface of magnetite/silica/poly(methacrylic acid-co-ethylene glycol dimethacrylate) (Fe3O4/SiO2/P(MAA-co-EGDMA)). And then simultaneous extraction and derivatization of the aldehydes were performed on the DNPH-adsorbed Fe3O4/SiO2/P(MAA-co-EGDMA). The simple, rapid and sensitive determination of hexanal and heptanal can be accomplished within 9min. Under optimized conditions, the limits of detection (LODs) were 1.7 and 2.5nmol/L for hexanal and heptanal, respectively. The relative recoveries ranged from 72.8% to 91.4% with the intra- and inter-day relative standard deviations (RSDs) being less than 9.6%. Furthermore, the proposed method was successfully applied to determine endogenous hexanal and heptanal in human urine from healthy persons and lung cancer patients. The results showed the higher concentrations of hexanal and heptanal were observed in lung cancer patients compared to healthy controls. Thus, the developed MSPE-ISD method is suitable for the determination of aldehydes in urines. PMID:25702985

  7. Development and validation of an automated solid-phase extraction and liquid chromatographic method for determination of lumefantrine in capillary blood on sampling paper.

    OpenAIRE

    Blessborn, D.; Ro?msing, S.; Annerberg, A.; Sundquist, D.; Bjo?rkman, A.; Lindegardh, N.; Bergqvist, Y.

    2007-01-01

    A bioanalytical method for the determination of lumefantrine in 100 microl blood applied onto sampling paper, by solid-phase extraction and liquid chromatography, has been developed and validated. Whatman 31 ET Chr sampling paper was pre-treated with 0.75 M tartaric acid before sampling capillary blood to enable a high recovery of lumefantrine. Lumefantrine was extracted from the sampling paper, then further purified using solid-phase extraction and finally quantified with HPLC. The between-d...

  8. Determination of trace labile copper in environmental waters by magnetic nanoparticle solid phase extraction and high-performance chelation ion chromatography.

    Science.gov (United States)

    Wei, Z; Sandron, S; Townsend, A T; Nesterenko, P N; Paull, B

    2015-04-01

    Cobalt magnetic nanoparticles surface functionalised with iminodiacetic acid were evaluated as a nano-particulate solid phase extraction absorbent for copper ions (Cu(2+)) from environmental water samples. Using an external magnetic field, the collector nanoparticles could be separated from the aqueous phase, and adsorbed ions simply decomplexed using dilute HNO3. Effects of pH, buffer concentration, sample and sorbent volume, extraction equilibrium time, and interfering ion concentration on extraction efficiency were investigated. Optimal conditions were then applied to the extraction of Cu(2+) ions from natural water samples, prior to their quantitation using high-performance chelation ion chromatography. The limits of detection (LOD) of the combined extraction and chromatographic method were ~0.1 ng ml(-1), based upon a 100-fold preconcentration factor (chromatographic performance; LOD=9.2 ng ml(-1) Cu(2+)), analytical linear range from 20 to 5000 ng mL(-1), and relative standard deviations=4.9% (c=1000 ng ml(-1), n=7). Accuracy and precision of the combined approach was verified using a certified reference standard estuarine water sample (SLEW-2) and comparison of sample determinations with sector field inductively coupled plasma mass spectrometry. Recoveries from the addition of Cu(2+) to impacted estuarine and rain water samples were 103.5% and 108.5%, respectively. Coastal seawater samples, both with and without prior UV irradiation and dissolved organic matter removal were also investigated using the new methodology. The effect of DOM concentration on copper availability was demonstrated. PMID:25640140

  9. Evaluation of Superparamagnetic Silica Nanoparticles for Extraction of Triazines in Magnetic in-Tube Solid Phase Microextraction Coupled to Capillary Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    R. A. González-Fuenzalida

    2014-04-01

    Full Text Available The use of magnetic nanomaterials for analytical applications has increased in the recent years. In particular, magnetic nanomaterials have shown great potential as adsorbent phase in several extraction procedures due to the significant advantages over the conventional methods. In the present work, the influence of magnetic forces over the extraction efficiency of triazines using superparamagnetic silica nanoparticles (NPs in magnetic in tube solid phase microextraction (Magnetic-IT-SPME coupled to CapLC has been evaluated. Atrazine, terbutylazine and simazine has been selected as target analytes. The superparamagnetic silica nanomaterial (SiO2-Fe3O4 deposited onto the surface of a capillary column gave rise to a magnetic extraction phase for IT-SPME that provided a enhancemment of the extraction efficiency for triazines. This improvement is based on two phenomena, the superparamegnetic behavior of Fe3O4 NPs and the diamagnetic repulsions that take place in a microfluidic device such a capillary column. A systematic study of analytes adsorption and desorption was conducted as function of the magnetic field and the relationship with triazines magnetic susceptibility. The positive influence of magnetism on the extraction procedure was demonstrated. The analytical characteristics of the optimized procedure were established and the method was applied to the determination of the target analytes in water samples with satisfactory results. When coupling Magnetic-IT-SPME with CapLC, improved adsorption efficiencies (60%–63% were achieved compared with conventional adsorption materials (0.8%–3%.

  10. Investigating the Retention Mechanisms of Liquid Chromatography Using Solid-Phase Extraction Cartridges

    Science.gov (United States)

    O'Donnell, Mary E.; Musial, Beata A.; Bretz, Stacey Lowery; Danielson, Neil D.; Ca, Diep

    2009-01-01

    Liquid chromatography (LC) experiments for the undergraduate analytical laboratory course often illustrate the application of reversed-phase LC to solve a separation problem, but rarely compare LC retention mechanisms. In addition, a high-performance liquid chromatography instrument may be beyond what some small colleges can purchase. Solid-phase

  11. Molecularly imprinted solid-phase extraction monolithic capillary column for selective extraction and sensitive determination of safranine T in wolfberry.

    Science.gov (United States)

    Su, Zihao; Zhai, Haiyun; Chen, Zuanguang; Zhou, Qing; Li, Jiangmei; Liu, Zhenping

    2014-02-01

    A method was developed to sensitively determine safranine T in wolfberry by molecularly imprinted solid-phase extraction (MISPE) coupled with high-performance liquid chromatography and laser-induced fluorescence detection (HPLC-LIF). The MISPE capillary monolithic column was prepared by water-bath in situ polymerization, using safranine T, methacrylic acid (MAA), and ethylene dimethacrylate (EDMA) as template, functional monomer, and cross-linker, respectively. The properties of the homemade MISPE capillary monolithic column, including capacity and specificity, were investigated under optimized conditions and the morphologies of inner polymers were characterized by scanning electron microscopy (SEM). The mean recoveries of safranine T in wolfberry ranged from 91.2 % to 92.9 % and the intraday and interday relative standard deviation (RSD) values all ranged from 3.4 % to 4.2 %. Good linearity was obtained over 0.001-1.0 ?g mL(-1) (r?=?0.9999) with a detection limit (S/N?=?3) of 0.4 ng g(-1). Under the selected conditions, enrichment factors of over 90-fold were obtained and the extraction on the monolithic column effectively cleaned up the wolfberry matrix. The results demonstrated that the proposed MISPE-HPLC-LIF method could be applied to sensitively determine safranine T in wolfberry. PMID:24343453

  12. Molecularly imprinted solid-phase extraction for selective extraction of bisphenol analogues in beverages and canned food.

    Science.gov (United States)

    Yang, Yunjia; Yu, Jianlong; Yin, Jie; Shao, Bing; Zhang, Jing

    2014-11-19

    This study aimed to develop a selective analytical method for the simultaneous determination of seven bisphenol analogues in beverage and canned food samples by using a new molecularly imprinted polymer (MIP) as a sorbent for solid-phase extraction (SPE). Liquid chromatography coupled to triple-quadruple tandem mass spectrometry (LC-MS/MS) was used to identify and quantify the target analytes. The MIP-SPE method exhibited a higher level of selectivity and purification than the traditional SPE method. The developed procedures were further validated in terms of accuracy, precision, and sensitivity. The obtained recoveries varied from 50% to 103% at three fortification levels and yielded a relative standard deviation (RSD, %) of less than 15% for all of the analytes. The limits of quantification (LOQ) for the seven analytes varied from 0.002 to 0.15 ng/mL for beverage samples and from 0.03 to 1.5 ng/g for canned food samples. This method was used to analyze real samples that were collected from a supermarket in Beijing. Overall, the results revealed that bisphenol A and bisphenol F were the most frequently detected bisphenols in the beverage and canned food samples and that their concentrations were closely associated with the type of packaging material. This study provides an alternative method of traditional SPE extraction for screening bisphenol analogues in food matrices. PMID:25350221

  13. Acrylamide-functionalized graphene micro-solid-phase extraction coupled to high-performance liquid chromatography for the online analysis of trace monoamine acidic metabolites in biological samples.

    Science.gov (United States)

    Yang, Xiaoting; Hu, Yufei; Li, Gongke; Zhang, Zhuomin

    2015-05-01

    Monoamine acidic metabolites in biological samples are essential biomarkers for the diagnosis of neurological disorders. In this work, acrylamide-functionalized graphene adsorbent was successfully synthesized by a chemical functionalization method and was packed in a homemade polyether ether ketone micro column as a micro-solid-phase extraction unit. This micro-solid-phase extraction unit was directly coupled to high-performance liquid chromatography to form an online system for the separation and analysis of three monoamine acidic metabolites including homovanillic acid, 5-hydroxyindole-3-acetic acid, and 3,4-dihydroxyphenylacetic acid in human urine and plasma. The online system showed high stability, permeability, and adsorption capacity toward target metabolites. The saturated extraction amount of this online system was 213.1, 107.0, and 153.4 ng for homovanillic acid, 5-hydroxyindole-3-acetic acid, and 3,4-dihydroxyphenylacetic acid, respectively. Excellent detection limits were achieved in the range of 0.08-0.25 ?g/L with good linearity and reproducibility. It was interesting that three targets in urine and plasma could be actually quantified to be 0.94-3.93 ?g/L in plasma and 7.15-19.38 ?g/L in urine. Good recoveries were achieved as 84.8-101.4% for urine and 77.8-95.1% for plasma with the intra- and interday relative standard deviations less than 9.3 and 10.3%, respectively. This method shows great potential for online analysis of trace monoamine acidic metabolites in biological samples. PMID:25655072

  14. 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

  15. Comparison of liquid-liquid extraction-thin layer chromatography with solid-phase extraction-high-performance thin layer chromatography in detection of urinary morphine

    OpenAIRE

    Ahadi, Ali; Partoazar, Alireza; Abedi-khorasgani, Mohammad-hassan; Shetab-boushehri, Seyed Vahid

    2011-01-01

    Liquid-liquid extraction-thin layer chromatography (LLE-TLC) has been a common and routine combined method for detection of drugs in biological materials. Solid-phase extraction (SPE) is gradually replacing the traditional LLE method. High performance thin layer chromatography (HPTLC) has several advantages over TLC. The present work studied the higher efficiency of a new SPE-HPTLC method over that of a routine LLE-TLC method, in extraction and detection of urinary morphine. Fifty-eight urine...

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

    Science.gov (United States)

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

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

  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

    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.

  18. 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.

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

    Science.gov (United States)

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

    2015-04-01

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

  20. 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%.

  1. A matrix solid-phase dispersion method for the extraction of seven pesticides from mango and papaya.

    Science.gov (United States)

    Navickiene, Sandro; Aquino, Adriano; Bezerra, Débora Santos Silva

    2010-10-01

    A simple and effective extraction method based on matrix solid-phase dispersion was developed to determine trichlorfon, pyrimethanil, methyl parathion, tetraconazole, thiabendazole, imazalil, and tebuconazole in papaya and mango using gas chromatography-mass spectrometry with selected ion monitoring. Different parameters of the method were evaluated, such as type of solid-phase (silica-gel, neutral alumina, and Florisil), the amount of solid-phase, and eluent [dichloromethane, ethyl acetate-dichloromethane (4:1, 1:4, 1:1, 2:3, v/v)]. The best results were obtained using 2.0 g of mango or papaya, 3.0 g of silica as dispersant sorbent, and ethyl acetate-dichloromethane (1:1, v/v) as eluting solvent. The method was validated using mango and papaya samples fortified with pesticides at different concentration levels (0.05, 0.10, and 1.0 mg/kg). Average recoveries (4 replicates) ranged from 80% to 146%, with relative standard deviations between 1.0% and 28%. Detection and quantification limits for mango and papaya ranged from 0.01 to 0.03 mg/kg and 0.05 to 0.10 mg/kg, respectively. The proposed method was applied to the analysis of these compounds in commercial fruit samples from a local market (Aracaju/SE, Brazil), and residues of the pesticides were not detected on the samples. PMID:20875237

  2. 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.

  3. Synthesis of molecularly imprinted polymers via ring-opening metathesis polymerization for solid-phase extraction of bisphenol A.

    Science.gov (United States)

    Wang, Xiaohong; Chen, Lirong; Xu, Xiaojie; Li, Yuanzong

    2011-09-01

    The use of molecularly imprinted polymers (MIPs) prepared by ring-opening metathesis polymerization (ROMP) for bisphenol A (BPA) was reported in this article. The resulting MIPs have high imprinting and adsorption capacities, and can be used for separation and determination of BPA in environmental water samples. The successful application of ROMP in the molecular imprinting field is described here. For the first time, two cross-linkers (dicyclopentadiene and 2,5-norbornadiene) and two Grubbs catalysts (first and second generation) were investigated to compare their effects on the binding performance of MIPs. The ROMP technique is able to create the imprinted polymers within 1 h under mild conditions. Furthermore, it can provide MIPs with obvious imprinting effects towards the template, very fast template rebinding kinetics, high binding capacity and appreciable selectivity over structurally related compounds. The adsorption process for MIPs in this study can be completed within 45 min, which is much faster than that of bulk MIPs synthesized by traditional free-radical polymerization. The resulting imprinting polymer was evaluated for its use as a sorbent support in an off-line solid-phase extraction approach to recover BPA from diluted aqueous samples. The optimized extraction protocol resulted in a reliable MISPE method suitable for selective extraction and preconcentration of BPA from tap water, human urine and liquid milk samples. This article demonstrates the practical feasibility of the MIPs prepared via ROMP as solid-phase extraction materials. PMID:21720736

  4. 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?gL(-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?gL(-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

  5. Novel dispersive micro-solid-phase extraction combined with ultrahigh-performance liquid chromatography-high-resolution mass spectrometry to determine morpholine residues in citrus and apples.

    Science.gov (United States)

    Chen, Dawei; Miao, Hong; Zou, Jianhong; Cao, Pei; Ma, Ning; Zhao, Yunfeng; Wu, Yongning

    2015-01-21

    This paper presents a new analytical method for the determination of morpholine residues in citrus and apples using a novel dispersive micro-solid-phase extraction (DMSPE), followed by ultrahigh-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS). Samples were extracted with 1% formic acid in acetonitrile/water (1:1, v/v) and then cleaned up using the DMSPE procedure. Morpholine from the extract was adsorbed to a polymer cation exchange sorbent and eluted with ammonium hydroxide/acetonitrile (3:97, v/v) through a 1 mL syringe with a 0.22 ?m nylon syringe filter. All of the samples were analyzed by UHPLC-HRMS/MS on a Waters Acquity BEH hydrophilic interaction chromatography column using 0.1% formic acid and 4 mM ammonium formate in water/acetonitrile as the mobile phase with gradient elution. The method showed good linearity (R(2) > 0.999) in the range of 1-100 ?g/L for the analyte. The limit of detection and limit of quantitation values of morpholine were 2 and 5 ?g/kg, respectively. The average recoveries of morpholine from the citrus and apple samples spiked at three different concentrations (5, 20, and 100 ?g/kg) were in a range from 78.4 to 102.7%. PMID:25539135

  6. 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 ...

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

    OpenAIRE

    Cid, Yara P.; Ferreira, Thais P.; Medeiros, Deborah M. V. C.; Oliveira, Rodrigo M.; Silva, Natha?lia C. C.; Magalha?es, Viviane S.; Scott, Fa?bio B.

    2012-01-01

    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 flow 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...

  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. Flame atomic absorption spectrometric determination of ?g amounts of Fe (III) ions after solid phase extraction using modified octadecyl silica membrane disks

    Science.gov (United States)

    Mashhadizadeh, Mohammad Hossein; Azimi, Mansoureh Sadat; Pesteh, Mahnaz; Sheikhshoaei, Iran; Ardakani, Mohammad Mazloum; Karimi, Mohammad Ali

    2008-08-01

    A simple, rapid and reliable method has been developed to selectively separate and concentrate ultra trace amounts of Fe (III) ions from aqueous samples for the measurement by flame atomic absorption spectrometry (FAAS). By the passage of aqueous samples through an octadecyl silica membrane disk modified by a recently synthesized Schiff base (Bis-(4-nitro phenyl azo) salisilidine-1,3-diamino propane), Fe(III) ions adsorb quantitatively and most of matrix elements will pass through the disk to drain. The retained iron ions are then stripped from the disk by minimal amount of 0.1 mol l - 1 sulfuric acid as eluent. Extraction efficiency and the influence of pH, flow rates, amount of ligand, type and least amount of stripping acid as eluent were evaluated. The recovery of the iron from aqueous solution on the membrane disk modified with 3 mg Schiff's base was quantitative over pH 2-4.5. The linear dynamic range of the proposed method for Fe (III) ions was found in a wide concentration range of 0.20 (± 0.05)-680 (± 2) ?g l - 1 . The detection limit and preconcentration factor of this solid phase extraction method were found 20.0 (± 0.7) ng l - 1 and 100 respectively. The reproducibility of the procedure is at the most 1.5%.

  10. Ultrasound assisted microextraction-nano material solid phase dispersion for extraction and determination of thymol and carvacrol in pharmaceutical samples: experimental design methodology.

    Science.gov (United States)

    Roosta, Mostafa; Ghaedi, Mehrorang; Daneshfar, Ali; Sahraei, Reza

    2015-01-15

    In the present study, for the first time, a new extraction method based on "ultrasound assisted microextraction-nanomaterial solid phase dispersion (UAME-NMSPD)" was developed to preconcentrate the low quantity of thymol and carvacrol in pharmaceutical samples prior to their HPLC-UV separation/determination. The analytes were accumulated on nickel sulfide nanomaterial loaded on activated carbon (NiS-NP-AC) that with more detail identified by XRD, FESEM and UV-vis technique. Central composite design (CCD) combined with desirability function (DF) was used to search for optimum operational conditions. Working under optimum conditions specified as: 10 min ultrasonic time, pH 3, 0.011 g of adsorbent and 600 ?L extraction solvent) permit achievement of high and reasonable linear range over 0.005-2.0 ?g mL(-1) (r(2)>0.9993) with LOD of thymol and carvacrol as 0.23 and 0.21 ?g L(-1), respectively. The relative standard deviations (RSDs) were less than 4.93% (n=3). PMID:25484348

  11. Solid-phase extraction and HPLC-MS profiling of pyrrolizidine alkaloids and their n-oxides: A case study of echium plantagineum

    Science.gov (United States)

    Pyrrolizidine alkaloids and their N-oxides can be extracted from the dried methanolic extracts of plant material using dilute aqueous acid. The subsequent integration of solid-phase extraction (with a strong cation exchanger) of the alkaloids and N-oxides from the aqueous acid solution, together wi...

  12. SOLID-PHASE EXTRACTION AND HPLC-MS PROFILING OF PYRROLIZIDINE ALKALOIDS AND THEIR N-OXIDES: A CASE STUDY OF ECHIUM PLANTAGINEUM

    Science.gov (United States)

    Pyrrolizidine alkaloids and their N-oxides can be extracted from the dried methanolic extracts of plant material using dilute aqueous acid. The subsequent integration of solid-phase extraction (with a strong cation exchanger) of the alkaloids and N-oxides from the aqueous acid solution, together wit...

  13. [Determination of ethyl glucuronide in human urine by solid phase extraction-gas chromatography-mass spectrometry].

    Science.gov (United States)

    Yu, Tianxiao; Li, Qing; Wan, Tao; Li, Jianbo; Ding, Shijia

    2011-02-01

    A solid phase extraction (SPE) and gas chromatography (GC) with mass spectrometry (MS) method for determination of ethyl glucuronide (EtG) in human urine was established. One mL urine sample was deproteinated by 100 microL 3 mol/L hydrochloric acid and cleaned up through a solid phase extraction column. The target analytes were eluted from an NH2-column with 4% ammonia solution and then treated with bis (trimethylsilyl) trifluoroacetamide (BSTFA) + trimethylchlorosilane (TMCS) (99:1) for derivatization. The derivatized samples were analyzed by GC-MS. Data were acquired in the selected ion monitoring (SIM) mode and the quantitation of EtG was done through internal standard method. Good linearity was obtained at the mass concentration range of 0.1 - 3.2 mg/L with a correlation coefficient (r) of 0.9921. The limit of detection (LOD) was 28.4 microg/L. The range of recoveries was 92.5% - 108.7%, and the relative standard deviations (RSDs) of intra-day and inter-day were all less than 5%. This method is sensitive, specific, accurate and can be applied to the determination of EtG for medicolegal identification and clinical laboratory. PMID:21598520

  14. 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

  15. 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)

  16. [Determination of short chain chlorinated paraffins in leather products by solid phase extraction coupled with gas chromatography-mass spectrometry].

    Science.gov (United States)

    Zhang, Weiya; Wan, Xin; Li, Lixia; Wang, Chengyun; Jin, Shupei; Xing, Jun

    2014-10-01

    The short chain chlorinated paraffins (SCCPs) are the additives frequently used in the leather production in China, but they have been put into the list of forbidden chemicals issued by European Union recently. In fact, there is not a commonly recognized method for the determination of the SCCPs in the leather products due to the serious matrix interferences from the leather products and the complex chemical structures of the SCCPs. A method of solid phase extraction coupled with gas chromatography-mass spectrometry (SPE-GC-MS) was established for the determination of the SCCPs in the leather products after the optimization of the SPE conditions. It was found that the interferences from the leather products were thor- oughly separated from the analyte of the SCCPs on a home-made solid phase extraction (SPE) column filled with silica packing while eluted with a mixed solvent of n-hexane-methylene chloride (2:1, v/v). With this method, the recoveries for the SCCPs spiked in the real leather samples varied from 90.47% to 99.00% with the relative standard deviations (RSDs) less than 6.7%, and the limits of detection (LODs) were between 0.069 and 0.110 mg/kg. This method is suitable for qualitative and quantitative analysis of SCCPs in the leather products. PMID:25739278

  17. Simultaneous determination of 12 illicit drugs in whole blood and urine by solid phase extraction and UPLC-MS/MS.

    Science.gov (United States)

    Zhang, Lin; Wang, Zhao-Hong; Li, Hong; Liu, Yong; Zhao, Meng; Jiang, Ye; Zhao, Wen-Song

    2014-04-01

    A rapid and sensitive method based on solid phase extraction and ultra performance liquid chromatography-electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) for the simultaneous determination of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylene-dioxymethamphetamine, N-methyl-1-(3,4-methyl-enedioxyphenyl)-2-butanamine, 3,4-methylenedioxyethylamphetamine, p-methoxymethamphetamine, ephedrine, N-methylephedrine, cathinone, methcathinone, and ketamine in whole blood and urine was developed and validated. Following solid phase extraction, the analytes were separated on ACQUITY UPLC BEH Phenyl column (100mm×2.1mm, 1.7?m) under gradient elution using a mobile phase containing of acetonitrile and 0.3% formic acid in water at a flow rate of 0.4mLmin(-1) and analyzed by a triplequadrupole mass spectrometer in the multiple reaction monitoring (MRM) mode. The proposed method was linear for each analyte with correlation coefficients over 0.99. Recovery validation studies showed accuracy bias below 4.4%. Acceptable precision was also obtained with a relative standard deviation below 8.9%. The sensitivity of the assay was found to be adequate for the quantitation of the illicit drugs in whole blood and urine sample and was higher than reported methods. The present method was proved to be reliable and robust for drug screening in forensic toxicological analysis. PMID:24631805

  18. 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.

  19. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of pesticides in water by C-18 solid-phase extraction and capillary-column gas chromatography/mass spectrometry with selected-ion monitoring

    Science.gov (United States)

    Zaugg, Steven D.; Sandstrom, Mark W.; Smith, Steven G.; Fehlberg, Kevin M.

    1995-01-01

    A method for the isolation of 41 pesticides and pesticide metabolites in natural-water samples using C-18 solid-phase extraction and determination by capillary-column gas chromatography/mass spectrometry with selected-ion monitoring is described. Water samples are filtered to remove suspended particulate matter and then are pumped through disposable solid-phase extraction columns containing octadecyl-bonded porous silica to extract the pesticides. The columns are dried using carbon dioxide or nitrogen gas, and adsorbed pesticides are removed from the columns by elution with 3.0 milliliters of hexane-isopropanol (3:1). Extracted pesticides are determined by capillary- column gas chromatography/mass spectrometry with selected-ion monitoring of three characteristic ions. The upper concentration limit is 4 micrograms per liter (g/L) for most pesticides, with the exception of widely used corn herbicides--atrazine, alachlor, cyanazine, and metolachlor--which have upper concentration limits of 20 g/L. Single- operator method detection limits in reagent-water samples range from 0.001 to 0.018 g/L. Average short-term single-operator precision in reagent- water samples is 7 percent at the 0.1- and 1.0-g/L levels and 8 percent at the 0.01-g/L level. Mean recoveries in reagent-water samples are 73 percent at the 0.1- and 1.0-g/L levels and 83 percent at the 0.01-g/L level. The estimated holding time for pesticides after extraction on the solid-phase extraction columns was 7 days. An optional on-site extraction procedure allows for samples to be collected and processed at remote sites where it is difficult to ship samples to the laboratory within the recommended pre-extraction holding time.

  20. Chemically modified polymeric resins for solid-phase extraction and group separation prior to analysis by liquid or gas chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, L.W.

    1993-07-01

    Polystyrene divinylbenzene was modified by acetyl, sulfonic acid, and quaternary ammonium groups. A resin functionalized with an acetyl group was impregnated in a PTFE membrane and used to extract and concentrate phenolic compounds from aqueous samples. The acetyl group created a surface easily wetted, making it an efficient adsorbent for polar compounds in water. The membrane stabilized the resin bed. Partially sulfonated high surface area resins are used to extract and group separate an aqueous mixture of neutral and basic organics; the bases are adsorbed electrostatically to the sulfonic acid groups, while the neutraons are adsorbed hydrophobically. A two-step elution is then used to separate the two fractions. A partially functionalized anion exchange resin is used to separate organic acids and phenols from neutrals in a similar way. Carboxylic acids are analyzed by HPLC and phenols by GC.

  1. Solid-phase extraction of trace metal ions with magnetic nanoparticles modified with 2,6-diaminopyridine

    International Nuclear Information System (INIS)

    We have modified silica-coated Fe3O4 nanoparticles with 2,6-diaminopyridine and used these for selective magnetic solid-phase extraction of trace amounts of metal ions. The nanoparticles were characterized by transmission electron microscopy and Fourier transform infrared spectroscopy. Quantitative extraction of trace amounts of Cu(II) and Zn(II) from mixed-ion solutions was accomplished at an optimal pH value of 6 within less than 10 min. The metal ions were eluted from the sorbent with hydrochloric acid. Common electrolytes and chemically related metal ions do not interfere. The relative standard deviations of the method are <4 %. It was successfully applied to the separation and preconcentration of trace metal ions from the certified reference materials GBW 08301 (river sediment) and GBW 08607 (water solution), in natural water, and in samples of vegetable with satisfying results. (author)

  2. Fast copper speciation screenings with solid-phase extraction cartridges using high-specific activity 64Cu

    International Nuclear Information System (INIS)

    Solid-phase extraction (SPE) cartridges with different functional groups (chelating, ion-exchange, hydrophobic) may be useful for copper speciation determinations of aqueous samples. Provided that each cartridge selectivity extracts one species or a group of species, a fast screening of copper speciation can be achieved by performing a series of extractions with different SPE cartridges and combining the results. For this purpose, the performance of five SPE cartridges was studied with respect to extraction selectivity using samples with known composition. Samples were spiked with a high-specific 64Cu radiotracer to achieve easy detection of extracted copper species. Its high radioactivity per unit of mass ensures preservation of initial chemical equilibria and composition of the sample. Results show that secondary interactions may take place on the extracting phase when relatively clean samples are analyzed. Two natural water samples, viz. a ditch water and a seawater sample, were exposed to a series of extractions as well. Species distributions found for these samples generally correspond to expected distributions. Secondary interactions may be suppressed in these cases, as other metal species compete for these interactions. (author)

  3. 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.

  4. Selective solid-phase extraction of artificial chemicals from milk samples using multiple-template surface molecularly imprinted polymers.

    Science.gov (United States)

    Zhang, Jing; Ni, Yan-Li; Wang, Ling-Ling; Ma, Jin-Qin; Zhang, Zhi-Qi

    2015-08-01

    A novel multiple-template surface molecularly imprinted polymer (MTMIP) was synthesized using ofloxacin and 17?-estradiol as templates and modified monodispersed poly(glycidylmethacrylate-co-ethylene dimethacrylate) (PGMA/EDMA ) beads as the support material. Static adsorption, solid-phase extraction and high-performance liquid chromatography were performed to investigate the adsorption properties and selective recognition characteristics of the polymer templates and their structural analogs. The maximum binding capacities of ofloxacin and 17?-estradiol on the MTMIP were 9.0 and 6.6?mg/g, respectively. Compared with the corresponding nonimprinted polymer, the MTMIP exhibited a much higher adsorption performance and selectivity toward three quinolones and three estrogens, which are common drug residues in food. The MTMIP served as a simple and effective pretreatment method and could be successfully applied to the simultaneous analysis of multiple target components in complex samples. Furthermore, the MTMIP may find useful applications as a solid-phase absorbent in the simultaneous determination of trace quinolones and estrogens in milk samples, as the recoveries were in the range 77.6-98.0%. Copyright © 2015 John Wiley & Sons, Ltd. PMID:25677633

  5. Surfactant-enhanced liquid-liquid microextraction coupled to micro-solid phase extraction onto highly hydrophobic magnetic nanoparticles

    International Nuclear Information System (INIS)

    We are presenting a simplified alternative method for dispersive liquid-liquid microextraction (DLLME) by resorting to the use of surfactants as emulsifiers and micro solid-phase extraction (?-SPE). In this combined procedure, DLLME of hydrophobic components is initially accomplished in a mixed micellar/microemulsion extractant phase that is prepared by rapidly mixing a non-ionic surfactant and 1-octanol in aqueous medium. Then, and in contrast to classic DLLME, the extractant phase is collected by highly hydrophobic polysiloxane-coated core-shell Fe2O3(at)C magnetic nanoparticles. Hence, the sample components are the target analyte in the DLLME which, in turn, becomes the target analyte of the ?-SPE step. This 2-step approach represents a new and simple DLLME procedure that lacks tedious steps such as centrifugation, thawing, or delicate collection of the extractant phase. As a result, the analytical process is accelerated and the volume of the collected phase does not depend on the volume of the extraction solvent. The method was applied to extract cadmium in the form of its pyrrolidine dithiocarbamate chelate from spiked water samples prior to its determination by FAAS. Detection limits were brought down to the low ?g L?1 levels by preconcentrating 10 mL samples with satisfactory recoveries (96.0–108.0 %). (author)

  6. 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: 4min for extraction time, 20mg for sorbent amount, 100mL for initial sample volume, toluene as desorption solvent, 0.6mL for desorption solvent volume, 6min 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?gL(-1) in the real matrix. The calibration curves were linear over the concentration ranges from 0.03 to 80?gL(-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

  7. Extraction of uranium from seawater using magnetic adsorbents

    International Nuclear Information System (INIS)

    A new process for the extraction of uranium from seawater was developed. In the process, uranium adsorption is effected using powdered magnetic adsorbents; the adsorbents are then separated from seawater using magnetic separation technology. This process is superior to a column method using a granulated hydrous titanium oxide adsorber bed in the following ways: (1) a higher rate of adsorption is realized because smaller particles are used in the uranium adsorption; and (2) blocking, which is inevitable in an adsorber bed, is eliminated. The composite hydrous titanium-iron oxide as a magnetic adsorbent having high uranium adsorption capacity and magnetization can be prepared by adding urea to a mixed solution of titanium sulfate and ferrous sulfate. Adsorption and desoprtion of uranium and the removal of the adsorbent using a small-scale uranium extraction plant (about 15 m3/d) is reported, and the feasibility of uranium extraction from seawater by this process is demonstrated. 10 figures

  8. 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.

  9. Determination of atrazine and its major degradation products in soil pore water by solid-phase extraction, chemical derivatization, and gas chromatography/mass spectrometry

    Science.gov (United States)

    Carter, D.S.

    1996-01-01

    This report describes a method for the determination of atrazine, desethylatrazine, deisopropylatrazine, didealkylatrazine, and hydroxyatrazine from soil pore waters by use of solid-phase extractionfollowed by chemical derivatization and gas chromatography/mass spectrometry. The analytes are isolated from the pore-water matrix byextraction onto a graphitized carbon-black cartridge. The cartridge is dried under vacuum, and adsorbed analytes are removed by elution with ethyl acetate followed by dichloromethane/methanol (7:3, volume/volume). Water is removed from the ethyl acetate fraction on an anhydrous sodium sulfate column. The combined fractions are solvent exchanged into acetonitrile, evaporated by use of a nitrogen stream, and derivatized by use of N- methyl-N-(tert-butyldimethylsilyl)- trifluoroacetamide. The derivatized extracts are analyzed by capillary-column gaschromatography/electron-impact mass spectrometry in the scan mode. Estimated method detection limits range from 0.03 to 0.07 micrograms per liter. The mean recoveries of all analytes and surrogates determined at 0.74 to 0.82 micrograms per liter in reagent water in soil pore water were 94 percent and 98 percent, respectively. The mean recoveries of all analytes and surrogates determined at 7.4 to 8.2 micrograms per liter in reagent water and in soil pore water were 96 percent and 97 percent,respectively. Recoveries were 90 percent or higher, regardless of analyte concentration or matrix composition, for all compounds excepthydroxyatrazine, whose recoveries were slightly lower (77 percent) at the low concentration.

  10. Assessment of a new method for the analysis of decomposition gases of polymers by a combining thermogravimetric solid-phase extraction and thermal desorption gas chromatography mass spectrometry.

    Science.gov (United States)

    Duemichen, E; Braun, U; Senz, R; Fabian, G; Sturm, H

    2014-08-01

    For analysis of the gaseous thermal decomposition products of polymers, the common techniques are thermogravimetry, combined with Fourier transformed infrared spectroscopy (TGA-FTIR) and mass spectrometry (TGA-MS). These methods offer a simple approach to the decomposition mechanism, especially for small decomposition molecules. Complex spectra of gaseous mixtures are very often hard to identify because of overlapping signals. In this paper a new method is described to adsorb the decomposition products during controlled conditions in TGA on solid-phase extraction (SPE) material: twisters. Subsequently the twisters were analysed with thermal desorption gas chromatography mass spectrometry (TDS-GC-MS), which allows the decomposition products to be separated and identified using an MS library. The thermoplastics polyamide 66 (PA 66) and polybutylene terephthalate (PBT) were used as example polymers. The influence of the sample mass and of the purge gas flow during the decomposition process was investigated in TGA. The advantages and limitations of the method were presented in comparison to the common analysis techniques, TGA-FTIR and TGA-MS. PMID:24929909

  11. 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

  12. A method to detect diphenylamine contamination of apple fruit and storages using headspace solid phase micro-extraction and gas chromatography/mass spectroscopy.

    Science.gov (United States)

    Song, Jun; Forney, Charles F; Jordan, Michael A

    2014-10-01

    Analysis of headspace concentrations of diphenylamine using solid phase micro-extraction (SPME) was examined for its suitability to detect DPA contamination and off-gassing in apple (Malus domestica) fruit, storage rooms and storage materials. Four SPME fibre coatings including polydimethylsiloxane (PDMS, 100 ?m), PDMS/divinylbenzene (PDMS/DVB), Polyacrylate (PA) and PDMS 7 ?m were evaluated. The average limits of detection and of quantification for head space DPA ranged from 0.13 to 0.72 ?g L(-1) and 0.42 to 2.35 ?g L(-1), respectively. Polyacrylate was identified to be the most suitable and compatible fibre for DPA analysis in apple samples, because of its high sensitivity to DPA and low fruit volatile interferences. SPME techniques were further applied to study contamination of DPA in apples, storage rooms and packaging materials. DPA was found in the air of storage rooms containing apples that were not treated with DPA. Wood and plastic bin material, bin liners, and foam insulation all adsorbed and off-gassed DPA and could be potential sources of contamination of untreated apples. PMID:24799236

  13. Flame Atomic Absorption Spectrometric Determination of Trace Amounts of Zinc and Thallium in Different Matrixes after Solid Phase Extraction on Modified Multiwalled Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Sayed Zia Mohammadi

    2012-05-01

    Full Text Available The potential of modified multiwallcd carbon nanotubes, as a solid-phase extraction sorbent for the simultaneous separation and preconcentration of zinc and thallium has been investigated. Zinc and thallium were adsorbed quantitatively onto modified multiwalled carbon nanotubes in the pH range of 3 - 6.5. Parameters influencing the simultaneous preconcentration of Zn(II and Tl(I ions such as pH of the sample, sample and eluent flow rate, type and volume of elution solution and interfering ions, have been examined and optimized. Linearity was maintained between 0.1 to 20.0 µg?mL–1 for thallium and 20.0 ng?mL–1 to 5.0 µg?mL–1 for zinc in the final solution. The defection limits based on three times the standard deviation of the blank signal (n = 8 for thallium and zinc were 5.1 and 1.4 ng?mL–1, respectively. Seven replicate determination of a mixture of 5.0 and 0.2 µg?mL–1 of thallium and zinc in the final solution gave a mean absorbance of 0.085 and 0.074 with relative standard deviation 1.5% and 1.7%, respectively. The method has been applied for the determination of trace amounts of zinc and thallium in biological and water sample with satisfactory results.

  14. Rapid determination of trace uranium in liquid wastes from spent nuclear-fuel reprocessing plants. Using on-line solid-phase extraction/electrochemical detection

    International Nuclear Information System (INIS)

    An on-line analysis system using a solid-phase extraction column coupled to electrochemical detection has been developed for the rapid determination of small amounts of uranium in liquid waste samples of spent nuclear-fuel reprocessing plants. A sample solution with a concentration of 3 M HNO3 was loaded onto a column: packed with U/TEVA resin. The interference elements were rinsed by passing 3 M HNO3 through the column. The adsorbed uranium was eluted with 0.1 M HNO3. The eluate was directly introduced into a flow-electrolysis cell. The reduction current of U(VI)?U(V) was monitored and recorded. The uranium concentration was calculated from the relation between the peak current and the concentration of the standard uranium solution. The result of five repeated analyses for a standard solution containing 2.5 ?g (0.1 mL at 25 ?g mL-1) of uranium was found to be 2.5 ± 0.025 ?g (mean ±1?). The detection limit calculated from 3-times the standard deviation of the background current was 56 ng. The analysis time required for one sample was within 5 min. The recoveries of uranium in actual nuclear waste reprocessing solutions were 92-112%. (author)

  15. 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.

  16. Cleanup and analysis of sugar phosphates in biological extracts by using solid phase extraction and anion-exchange chromatography with pulsed amperometric detection

    DEFF Research Database (Denmark)

    Smith, Hans Peter; Cohen, A.

    1998-01-01

    A cleanup method based on anion-exchange solid-phase extraction (SPE) was developed to render biological extracts suitable for the analysis of hexose phosphates with a modified anion-exchange chromatography method and pulsed amperometric detection. The method was applied to cell extracts of Saccharomyces cerevisiae obtained by using cold methanol as quenching agent and chloroform as extraction solvent. It was shown that pretreatment of the cell extract with SPE markedly improved the quality of the liquid chromatography analysis with recoveries of the sugar phosphates close to 100%. Furthermore, the method allowed for sample enrichment and the original extraction procedure could be simplified by implementing SPE early in the extraction protocol. (C) 1998 Academic Press.

  17. Streamlined sample cleanup using combined dispersive solid-phase extraction and in-vial filtration for analysis of pesticides and environmental pollutants in shrimp

    Science.gov (United States)

    A new method of sample preparation was developed and is reported for the first time. The approach combines in-vial filtration with dispersive solid-phase extraction (d-SPE) in a fast and convenient cleanup of QuEChERS (quick, easy, cheap, effective, rugged, and safe) extracts. The method was appli...

  18. Comparison of characteristic flavor and aroma volatiles in melons and standards using solid phase microextraction (SPME) and Stir Bar Sorptive Extraction (SBSE) with GC-MS.

    Science.gov (United States)

    Stir bar sorptive extraction (SBSE) is a technique for extraction and analysis of organic compounds in aqueous matrices, similar in theory to solid phase microextraction (SPME). SBSE has been successfully used to analyze several organic compounds, including food matrices. When compared with SPME, ...

  19. Magnetic graphene solid-phase extraction for the determination of carbamate pesticides in tomatoes coupled with high performance liquid chromatography.

    Science.gov (United States)

    Li, Na; Chen, Juan; Shi, Yan-Ping

    2015-08-15

    Graphene-based magnetic nanoparticles, comprising zero-valent iron, iron oxide-oxyhydroxide and graphene, were prepared through a simple one-step synthesis method, and subsequently applied to magnetic solid-phase extraction for the determination of trace carbamate pesticides in tomatoes coupled with high performance liquid chromatography. The properties of the nanocomposites were confirmed by using Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and vibrating sample magnetometer. The components within the nanocomposites endowed the material with high extraction performance and manipulative convenience. Compared with reduced graphene oxide, the as-prepared G-MNPs showed the better extraction efficiencies for the carbamate pesticides thanks to the contribution of the iron-containing magnetic nanoparticles to the adsorption capacity of the nanocomposites. Various experimental parameters affecting the extraction efficiency had been investigated in detail. Under the optimal conditions, the method provided high enrichment factors ranging from 364 to 434, good linearities ranging from 5 to 200ng g(-1) for metolcarb, baygon and methiocarb and 10 to 200ng g(-1) for carbofuran and isoprocarb, low limits of detection ranging from 0.58 to 2.06ng g(-1), and satisfactory spiked recoveries (between 90.34% and 101.98% with the relative standard deviation values from 1.21% to 5.93%). It was confirmed that this novel method was an efficient pretreatment and enrichment procedure and could be successfully applied for extraction and determination of trace carbamate pesticides in complex matrices. PMID:25966405

  20. 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.

    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 a correlation coefficient of 0.9994. The precision expressed as relative standard deviation was better than 2% in this range. The estimated limit of detection was 2 mu g/l and the experimentally verified quantification limit was 5 mu g/l, giving a relative standard deviation less than 2%. (C) 2000 Elsevier Science B.V. All rights reserved

  1. Trace determination of pharmaceuticals and other wastewater-derived micropollutants by solid phase extraction and gas chromatography/mass spectrometry.

    Science.gov (United States)

    Bisceglia, Kevin J; Yu, Jim T; Coelhan, Mehmet; Bouwer, Edward J; Roberts, A Lynn

    2010-01-22

    The presence of pharmaceuticals and other wastewater-derived micropollutants in surface and groundwaters is receiving intense public and scientific attention. Yet simple GC/MS methods that would enable measurement of a wide range of such compounds are scarce. This paper describes a GC/MS method for the simultaneous determination of 13 pharmaceuticals (acetaminophen, albuterol, allopurinol, amitriptyline, brompheniramine, carbamazepine, carisoprodol, ciclopirox, diazepam, fenofibrate, metoprolol, primidone, and terbinafine) and 5 wastewater-derived contaminants (caffeine, diethyltoluamide, n-butylbenzene sulfonamide, n-nonylphenol, and n-octylphenol) by solid phase extraction (SPE) and derivatization with BSTFA. The method was applied to the analysis of raw and treated sewage samples obtained from a wastewater treatment plant located in the mid-Atlantic United States. All analytes were detected in untreated sewage, and 14 of the 18 analytes were detected in treated sewage. PMID:20015510

  2. Enrichment/separation of cadmium(II) and lead(II) in environmental samples by solid phase extraction

    International Nuclear Information System (INIS)

    A preconcentration/separation procedure is presented for the solid phase extraction of trace cadmium and lead ions as their 1-(2-pyridylazo) 2-naphthol (PAN) chelates in environmental samples on Chromosorb-106 resin, prior to cadmium and lead determinations by atomic absorption spectrometry. The preconcentration procedure was optimized by using model solutions containing cadmium and lead ions. The influences of pH of the model solutions, amounts of PAN, eluent type and volume etc. were investigated. Also the effects of the matrix constituents of the samples were also examined. Separation of cadmium and lead from real samples was achieved quantitatively. The procedure presented was checked with the analysis of microwave-digested standard reference materials (IAEA-336 Lichen and SRM 1515 Apple leaves). The preconcentration procedure was applied for the lead and cadmium contents of the natural water samples, some salts with satisfactory results (recoveries >95%, relative standard deviations <8%)

  3. p-tert-Butylcalix[8]arene loaded silica gel for preconcentration of uranium(VI) via solid phase extraction

    International Nuclear Information System (INIS)

    This paper reports silica gel loaded with p-tert-butylcalix[8]arene as a new solid phase extractor for determination of trace level of uranium. Effective extraction conditions were optimized in column methods prior to determination by spectrophotometry using arsenazo(III). The results showed that U(VI) ions can be sorbed at pH 6 in a mini-column and quantitative recovery of U(VI) (>95-98%) was achieved by stripping 0.4 mol L-1 HCl. The sorption capacity of the functionalized sorbent is 0.072 mmol uranium(VI) g-1 modified silica gel. The relative standard deviation and detection limit were 1.2% (n = 10) for 1 ?g uranium(VI) mL-1 solution and 0.038 ?g L-1, respectively. The method was employed to the preconcentration of U(VI) ions from spiked ground water samples. (author)

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

    Directory of Open Access Journals (Sweden)

    Yara P. Cid

    2012-01-01

    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 flow 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.

  5. 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.

    2063-20-01

    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.

  6. 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)

  7. Multi-element pre-concentration of heavy metal ions by solid phase extraction on Chromosorb 108

    International Nuclear Information System (INIS)

    A multi-element preconcentration procedure for solid phase extraction on Chromosorb 108 as bathocuproinedisulfonic acid chelates and flame atomic absorption spectrometric determinations of some heavy metal ions in environmental samples is proposed in the present work. The influences of analytical parameters including pH of the aqueous solution, amounts of reagents, flow rates of sample and eluent solutions, sample volume etc. on the quantitative recoveries of copper, cadmium, lead, zinc, manganese, iron, chromium, nickel and cobalt ions were investigated. The effects of concomitant ions on the retentions of the analytes were also examined. The presented preconcentration procedure was applied to the determination of metal ions in reference standard materials (NRCC-SLRS 4 Riverine Water, SRM 1515 Apple leaves and GBW 07605 Tea) and some real samples including tap and river water, red wine, rice, black tea and honey

  8. 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.

  9. 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 0.005molL(-1) Na2HPO4 contained 1molL(-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

  10. Micro-solid-phase extraction of organochlorine pesticides using porous metal-organic framework MIL-101 as sorbent.

    Science.gov (United States)

    Huang, Zhenzhen; Lee, Hian Kee

    2015-07-01

    In this study, a metal-organic framework material, MIL-101, used as a micro-solid-phase extraction (?-SPE) sorbent for efficient enrichment of five organochlorine pesticides (OCPs), including ?-HCH, Aldrin, ?-Chlordane, Dieldrin and p,p'-DDD from water samples, followed by gas chromatography-mass spectrometry, is reported. This study demonstrated a new application of MIL-101 using ?-SPE, an advantage of the latter being its ability to process complex aqueous matrices, due to the protection of the sorbent afforded by the hollow fiber membrane bag. Key factors affecting extraction efficiency were studied, including elution solvent, extraction and desorption time. Under the optimal extraction conditions, the calibration plots were linear from 0.05 to 50ng/mL for ?-HCH and p,p'-DDD, and 0.1 to 50ng/mL for the other three analytes. The limits of detection were between 0.0025 and 0.016ng/mL. The relative recoveries of the OCPs spiked into real water samples (at 5ng/mL of each analyte) ranged from 87.6 to 98.6% with relative standard deviations of <10%. PMID:25987299

  11. 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

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

    Science.gov (United States)

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

    2014-11-01

    A novel approach for the selective extraction of organic target compounds from water samples has been developed using a mixed-bed solid phase extraction (mixed-bed SPE) technique. The molecularly imprinted polymer (MIP) particles are embedded in a network of silica gel to form a stable uniform porous bed. The capabilities of this method are demonstrated using atrazine as a model compound. In comparison to conventional molecularly imprinted-solid phase extraction (MISPE), the proposed mixed-bed MISPE method in combination with gas chromatography-mass spectrometry (GC-MS) analysis enables more reproducible and efficient extraction performance. After optimization of operational parameters (polymerization conditions, bed matrix ingredients, polymer to silica gel ratio, pH of the sample solution, breakthrough volume plus washing and elution conditions), improved LODs (1.34 µg L(-1) in comparison to 2.25 µg L(-1) obtained using MISPE) and limits of quantification (4.5 µg L(-1) for mixed-bed MISPE and 7.5 µg L(-1) for MISPE) were observed for the analysis of atrazine. Furthermore, the relative standard deviations (RSDs) for atrazine at concentrations between 5 and 200 µg L(-1) ranged between 1.8% and 6.3% compared to MISPE (3.5-12.1%). Additionally, the column-to-column reproducibility for the mixed-bed MISPE was significantly improved to 16.1%, compared with 53% that was observed for MISPE. Due to the reduced bed-mass sorbent and at optimized conditions, the total amount of organic solvents required for conditioning, washing and elution steps reduced from more than 25 mL for conventional MISPE to less than 2 mL for mixed-bed MISPE. Besides reduced organic solvent consumption, total sample preparation time of the mixed-bed MISPE method relative to the conventional MISPE was reduced from more than 20 min to less than 10 min. The amount of organic solvent required for complete elution diminished from 3 mL (conventional MISPE) to less than 0.4 mL with the mixed-bed technique shows its inherent potential for online operation with an analytical instrument. In order to evaluate the selectivity and matrix effects of the developed mixed-bed MISPE method, it was applied as an extraction technique for atrazine from environmental wastewater and river water samples. PMID:25127575

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

    International Nuclear Information System (INIS)

    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-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.

  14. Quantitation of promethazine and metabolites in urine samples using on-line solid-phase extraction and column-switching

    Science.gov (United States)

    Song, Q.; Putcha, L.; Harm, D. L. (Principal Investigator)

    2001-01-01

    A chromatographic method for the quantitation of promethazine (PMZ) and its three metabolites in urine employing on-line solid-phase extraction and column-switching has been developed. The column-switching system described here uses an extraction column for the purification of PMZ and its metabolites from a urine matrix. The extraneous matrix interference was removed by flushing the extraction column with a gradient elution. The analytes of interest were then eluted onto an analytical column for further chromatographic separation using a mobile phase of greater solvent strength. This method is specific and sensitive with a range of 3.75-1400 ng/ml for PMZ and 2.5-1400 ng/ml for the metabolites promethazine sulfoxide, monodesmethyl promethazine sulfoxide and monodesmethyl promethazine. The lower limits of quantitation (LLOQ) were 3.75 ng/ml with less than 6.2% C.V. for PMZ and 2.50 ng/ml with less than 11.5% C.V. for metabolites based on a signal-to-noise ratio of 10:1 or greater. The accuracy and precision were within +/- 11.8% in bias and not greater than 5.5% C.V. in intra- and inter-assay precision for PMZ and metabolites. Method robustness was investigated using a Plackett-Burman experimental design. The applicability of the analytical method for pharmacokinetic studies in humans is illustrated.

  15. Simple and selective spectrophotometric determination of ruthenium after solid phase extraction with some quinoxaline dyes into microcrystalline p-dichlorobenzene

    Science.gov (United States)

    Amin, Alaa S.

    2002-07-01

    A simple selective and highly sensitive extraction method has been developed for the determination of ruthenium spectrophotometrically after extraction of its 2,3-dichloro-6-(3-carboxy-2-hydroxy-1-naphthylazo)quinoxaline (I), 2,3-dichloro-6-(2-hydroxy-3,5-dinitrophenylazo)quinoxaline (II) and 2,3-dichloro-6-(2,7-dihydroxy-naphthylazo)quinoxaline (III) complexes into microcrystalline p-dichlorobenzene. The optimization of experimental conditions for the procedure is studied. The solid p-dichlorobenzene containing the ruthenium-reagent (I-III) complexes is separated by filtration and dissolved in N, N-dimethylformamide. The absorbance is measured at ?max 622, 518 and 542 nm against reagents I, II and III, respectively, as blank. Beer's law is obeyed upto 2.5 ?g ml -1 of ruthenium. The molar absorptivity, Sandell sensitivity, detection and quantification limits are calculated, when compared with those parameters without using solid phase extraction method. The interference of various ions has been studied in detail and the statistical evaluation of the experimental results is reported. The proposed methods have been successfully applied for the determination of trace amount of ruthenium in seawater, ore and metallurgy products.

  16. 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.

    2204-22-01

    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.

  17. 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

  18. A novel magnetic poly(aniline-naphthylamine)-based nanocomposite for micro solid phase extraction of rhodamine B.

    Science.gov (United States)

    Bagheri, Habib; Daliri, Rasoul; Roostaie, Ali

    2013-09-10

    A novel Fe3O4-poly(aniline-naphthylamine)-based nanocomposite was synthesized by chemical oxidative polymerization process as a magnetic sorbent for micro solid phase extraction. The scanning electron microscopy images of the synthesized nanocomposite revealed that the copolymer posses a porous structure with diameters less than 50nm. The extraction efficiency of this sorbent was examined by isolation of rhodamine B, a mutagenic and carcinogenic dye, from aquatic media in dispersion mode. Among different synthesized polymers, Fe3O4/poly(aniline-naphthylamine) nanocomposite showed a prominent efficiency. Parameters including the desorption solvent, amount of sorbent, desorption time, sample pH, ionic strength, extraction time and stirring rate were optimized. Under the optimum condition, a linear spiked calibration curve in the range of 0.35-5.00?gL(-1) with R(2)=0.9991 was obtained. The limits of detection (3Sb) and limits of quantification (10Sb) of the method were 0.10?gL(-1) and 0.35?gL(-1) (n=3), respectively. The relative standard deviation for water sample with 0.5?gL(-1) of RhB was 4.2% (n=5) and the absolute recovery was 92%. The method was applied for the determination of rhodamine B in dishwashing foam, dishwashing liquid, shampoo, pencil, matches tips and eye shadows samples and the relative recovery percentage were in the range of 94-99%. PMID:23972973

  19. A solid-phase extraction method for rapidly determining the adsorption coefficient of pharmaceuticals in sewage sludge

    Science.gov (United States)

    Berthod, Laurence; Roberts, Gary; Whitley, David C.; Sharpe, Alan; Mills, Graham A.

    2014-01-01

    The partitioning of pharmaceuticals in the environment can be assessed by measuring their adsorption coefficients (Kd) between aqueous and solid phases. Measuring this coefficient in sewage sludge gives an indication of their partitioning behaviour in a wastewater treatment plant and hence contributes to an understanding of their subsequent fate. The regulatory approved method for measuring Kd in sewage sludge is the US Environmental Protection Agency's Office of Prevention, Pesticides and Toxic Substances (OPPTS) guideline 835.1110, which is labour intensive and time consuming. We describe an alternative method for measuring the Kd of pharmaceuticals in sewage sludge using a modified solid-phase extraction (SPE) technique. SPE cartridges were packed at different sludge/PTFE ratios (0.4, 6.0, 24.0 and 40.0% w/w sludge) and eluted with phosphate buffer at pH 7.4. The approach was tested initially using three pharmaceuticals (clofibric acid, diclofenac and oxytetracycline) that covered a range of Kd values. Subsequently, the sorption behaviour of ten further pharmaceuticals with varying physico-chemical properties was evaluated. Results from the SPE method were comparable to those of the OPPTS test, with a correlation coefficient of 0.93 between the two approaches. SPE cartridges packed with sludge and PTFE were stable for up to one year; use within one month reduced variability in measurements (to a maximum of 0.6 log units). The SPE method is low-cost, easy to use and enables the rapid measurement of Kd values for a large number of chemicals. It can be used as an alternative to the more laborious full OPPTS test in environmental fate studies and risk assessments. PMID:25299795

  20. 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 froast 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)

  1. 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).…

  2. Methods of analysis by the U. S. Geological Survey National Water Quality Laboratory - determination of organonitrogen herbicides in water by solid-phase extraction and capillary-column gas chromatography/mass spectrometry with selected-ion monitoring

    Science.gov (United States)

    Sandstrom, Mark W.; Wydoski, Duane S.; Schroeder, Michael P.; Zamboni, Jana L.; Foreman, William T.

    1992-01-01

    A method for the isolation of organonitrogen herbicides from natural water samples using solid-phase extraction and analysis by capillary-column gas chromatography/mass spectrometry with selected-ion monitoring is described. Water samples are filtered to remove suspended particulate matter and then are pumped through disposable solid-phase extraction cartridges containing octadecyl-bonded porous silica to remove the herbicides. The cartridges are dried using carbon dioxide, and adsorbed herbicides are removed from the cartridges by elution with 1.8 milliliters of hexaneisopropanol (3:1). Extracts of the eluants are analyzed by capillary-column gas chromatography/mass spectrometry with selected-ion monitoring of at least three characteristic ions. The method detection limits are dependent on sample matrix and each particular herbicide. The method detection limits, based on a 100-milliliter sample size, range from 0.02 to 0.25 microgram per liter. Recoveries averaged 80 to 115 percent for the 23 herbicides and 2 metabolites in 1 reagent-water and 2 natural-water samples fortified at levels of 0.2 and 2.0 micrograms per liter.

  3. Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory - Determination of Moderate-Use Pesticides and Selected Degradates in Water by C-18 Solid-Phase Extraction and Gas Chromatography/Mass Spectrometry

    Science.gov (United States)

    Sandstrom, Mark W.; Stroppel, Max E.; Foreman, William T.; Schroeder, Michael P.

    2001-01-01

    A method for the isolation and analysis of 21 parent pesticides and 20 pesticide degradates in natural-water samples is described. Water samples are filtered to remove suspended particulate matter and then are pumped through disposable solid-phase-extraction columns that contain octadecyl-bonded porous silica to extract the analytes. The columns are dried by using nitrogen gas, and adsorbed analytes are eluted with ethyl acetate. Extracted analytes are determined by capillary-column gas chromatography/mass spectrometry with selected-ion monitoring of three characteristic ions. The upper concentration limit is 2 micrograms per liter (?g/L) for most analytes. Single-operator method detection limits in reagent-water samples range from 0.00 1 to 0.057 ?g/L. Validation data also are presented for 14 parent pesticides and 20 degradates that were determined to have greater bias or variability, or shorter holding times than the other compounds. The estimated maximum holding time for analytes in pesticide-grade water before extraction was 4 days. The estimated maximum holding time for analytes after extraction on the dry solid-phase-extraction columns was 7 days. An optional on-site extraction procedure allows for samples to be collected and processed at remote sites where it is difficult to ship samples to the laboratory within the recommended pre-extraction holding time. The method complements existing U.S. Geological Survey Method O-1126-95 (NWQL Schedules 2001 and 2010) by using identical sample preparation and comparable instrument analytical conditions so that sample extracts can be analyzed by either method to expand the range of analytes determined from one water sample.

  4. Solid-phase extraction using EmporeTM Radium Rad Disks to separate radium from thorium

    International Nuclear Information System (INIS)

    A new method is presented for rapid and selective enrichment of radium in natural samples using 225Ra as a chemical yield tracer. The new technique allows a complete separation of the target nuclide from the sample matrix with high separation factors for thorium and uranium. The use of EmporeTM Radium Rad Disks combines the easy handling of column chromatography with the high selectivity and rapid extraction kinetics of solvent extraction chromatography. Following this new chemical approach, eluates are obtained which are well suited for ?-spectrometric analysis of Ra, Th and U. (author)

  5. Removal of cesium and strontium from nuclear wastes using solid phase extraction membranes

    International Nuclear Information System (INIS)

    Battelle Pacific Northwest Laboratory (PNL), Westinghouse Idaho Nuclear Co. (WINCO), 3M, and IBC Advanced Technologies, Inc. have demonstrated the removal of strontium and cesium from Idaho National Engineering Laboratory (INEL) radioactive acidic waste using 3M web technology. The acidic waste experiments duplicated simulated open-quotes coldclose quotes test results and confirmed selective removal provided by IBC ligand-particles (Sr, Pb) and ion exchange (Cs) membranes. This same technology can be applied to other adsorbents that have been prepared as fine particles, too fine for use in standard ion exchange columns because they would create too much back pressure. The 3M method which was used to incorporate particles into membranes is flexible so that almost any material with an average particle size of 2-80 micrometers can be made into membrane. Therefore, a number of absorbents that could only be made as fine particles can now be utilized. Other absorbents which are large enough for column use can be ground to finer size and incorporated into membranes. They can then be utilized at much higher flow rates to achieve more rapid separations

  6. 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.

  7. 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, st...

  8. Head-Space Solid Phase Micro-extraction Followed by GC/MS Analysis of the Volatile Components in Seeds of Cinnamonum camphora

    OpenAIRE

    Yang Yong; Tao Wenyi

    2005-01-01

    The volatile components in seeds of Cinnamomum camphora were analyzed by Solid Phase Micro-extraction (SPME) combined with GC/MS. Twenty four main kinds of volatile compounds, among which the Sesquiterpene (29%), 3-Hexen-2-one (25%) and Monoterpene (10.22%), were separated and analyzed.

  9. DEVELOPMENT OF METHOD 535 FOR THE DETERMINATION OF CHLOROACETANILIDE AND OTHER ACETAMIDE HERBICIDE DEGRADATES IN DRINKING WATER BY SOLID PHASE EXTRACTION AND LIQUID CHROMATOGRAPHY/TANDEM MASS SPECTROMETRY

    Science.gov (United States)

    EPA Method 535 has been developed in order to provide a method for the analysis of "Alachlor ESA and other acetanilide degradation products" which are listed on U.S. EPA's 1998 Drinking Water Contaminant Candidate List. Method 535 uses solid phase extraction with a nonporous gr...

  10. An absorbing microwave micro-solid-phase extraction device used in non-polar solvent microwave-assisted extraction for the determination of organophosphorus pesticides

    International Nuclear Information System (INIS)

    Highlights: ? An absorbing microwave ?-SPE device packed with activated carbon was used. ? Absorbing microwave ?-SPE device was made and used to enrich the analytes. ? Absorbing microwave ?-SPE device was made and used to heat samples directly. ? MAE-?-SPE was applied to the extraction of OPPs with non-polar solvent only. - Abstract: A single-step extraction-cleanup method, including microwave-assisted extraction (MAE) and micro-solid-phase extraction (?-SPE), was developed for the extraction of ten organophosphorus pesticides in vegetable and fruit samples. Without adding any polar solvent, only one kind of non-polar solvent (hexane) was used as extraction solvent in the whole extraction step. Absorbing microwave ?-SPE device, was prepared by packing activated carbon with microporous polypropylene membrane envelope, and used as not only the sorbent in ?-SPE, but also the microwave absorption medium. Some experimental parameters effecting on extraction efficiency was investigated and optimized. 1.0 g of sample, 8 mL of hexane and three absorbing microwave ?-SPE devices were added in the microwave extraction vessel, the extraction was carried out under 400 W irradiation power at 60 °C for 10 min. The extracts obtained by MAE-?-SPE were directly analyzed by GC–MS without any clean-up process. The recoveries were in the range of 93.5–104.6%, and the relative standard deviations were lower than 8.7%.

  11. 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.

  12. Graphene oxide-based microspheres for the dispersive solid-phase extraction of non-steroidal estrogens from water samples.

    Science.gov (United States)

    Wen, Yingying; Niu, Zongliang; Ma, Yanling; Ma, Jiping; Chen, Lingxin

    2014-11-14

    A modified Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method based on the dispersive solid-phase extraction (dSPE) combined with high performance liquid chromatography (HPLC) was developed for the determination of non-steroidal estrogens in water samples. In this study, graphene oxide-based silica microspheres (SiO2@GO) were used as dSPE material for the preconcentration of analytes. HPLC was used for the separation and detection. This was the first time that the synthesized SiO2@GO microspheres were used as stationary phases for the off-line preconcentration of the non-steroidal estrogens in dSPE. dSPE parameters, such as sample pH, volume and type of eluent were optimized. Application of the developed method to analyze spiked lake, reservoir and tap water samples resulted in good recoveries values ranging from 70 to 106% with relative standard deviation values lower than 7.0% in all cases. Limits of detection were in the range of 0.2-6.1 ?g/L. The combined data obtained in this study recommended that the proposed method is very fast, simple, repeatable and accurate for the detection of non-steroidal estrogens. Furthermore, the SiO2@GO microspheres application could potentially be expanded to extract and pre-concentrate other compounds in various matrices. PMID:25441340

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

    Science.gov (United States)

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

    2015-05-29

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

  14. Multiresidue determination of pesticides in juice by solid-phase extraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Albero, Beatriz; Sánchez-Brunete, Consuelo; Tadeo, José L

    2005-05-15

    A multiresidue method based on solid-phase extraction was developed for the simultaneous determination of 50 pesticides in commercial juices. The extraction procedure was carried out in C(18) columns preconditioned with acetonitrile and water. The subsequent elution of pesticides was performed with a mixture of hexane-ethyl acetate (1:1, v/v) prior to the determination by gas chromatography with electron impact mass spectrometric detection in the selected ion monitoring mode (GC-MS-SIM), using one target and two qualifier ions. Standards were prepared spiking blank juice samples to counteract the observed matrix effect. Average recoveries for all the pesticides studied were higher than 91% with relative standard deviations lower than 9% in the concentration range of 0.02-0.1mug/mL and the detection limits achieved ranged from 0.1 to 4.6mug/L. The proposed method was applied to the analysis of these compounds in commercial juices and diazinon, ethion and procymidone were the pesticides encountered, although the levels found were very low. PMID:18970072

  15. Gamma-ray spectrometry of short-lived radionuclides in rain water collected with solid phase extraction disk

    International Nuclear Information System (INIS)

    An analytical method for short-lived nuclides in rainwater using ?-ray spectrometry combined with solid-phase extraction on an ion-exchange extraction disk has been developed. Rapid pretreatment is important in determining radioactive nuclides in rainwater, because short-lived nuclides disintegrate and decrease for sampling and measurements. The appropriate measurement time for each radioactive nuclide in rainwater was considered. The disk-shaped ion-exchange resin and chelating resin enable a simple concentration of trace metals in environmental water. A rainwater sample was passed through EmporeTM ion-exchange disks of Cation-SR and Anion-SR, pretreated with methanol for 10 minutes. The radioactivity of short-lived nuclides in rainwater samples was determined by using a HP-Ge spectrometer. Several environmental radionuclides (7Be, 131I, 134Cs, 137Cs, 212Pb, 214Pb, 212Bi and 214Bi) were identified on the gamma-ray spectra of rainwater samples. A spike test for three analytes (Tl, Pb and Bi) showed good recoveries (94 - 100%) for rainwater. The present method is more rapid than the conventional method. (author)

  16. 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)

  17. 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.

  18. 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.

  19. A high performance system to study the influence of temperature in on-line solid-phase extraction capillary electrophoresis.

    Science.gov (United States)

    Tascon, Marcos; Benavente, Fernando; Sanz-Nebot, Victoria; Gagliardi, Leonardo G

    2015-03-10

    A novel high performance system to control the temperature of the microcartridge in on-line solid phase extraction capillary electrophoresis (SPE-CE) is introduced. The mini-device consists in a thermostatic bath that fits inside of the cassette of any commercial CE instrument, while its temperature is controlled from an external circuit of liquid connecting three different water baths. The circuits are controlled from a switchboard connected to an array of electrovalves that allow to rapidly alternate the water circulation through the mini-thermostatic-bath between temperatures from 5 to 90 °C. The combination of the mini-device and the forced-air thermostatization system of the commercial CE instrument allows to optimize independently the temperature of the sample loading, the clean-up, the analyte elution and the electrophoretic separation steps. The system is used to study the effect of temperature on the C18-SPE-CE analysis of the opioid peptides, Dynorphin A (Dyn A), Endomorphin1 (END) and Met-enkephalin (MET), in both standard solutions and in spiked plasma samples. Extraction recoveries demonstrated to depend, with a non-monotonous trend, on the microcartridge temperature during the sample loading and became maximum at 60 °C. Results prove the potential of temperature control to further enhance sensitivity in SPE-CE when analytes are thermally stable. PMID:25732315

  20. Determination of selected phenothiazines in human plasma by solid-phase extraction and liquid chromatography with coulometric detection.

    Science.gov (United States)

    Saracino, Maria Addolorata; Amore, Mario; Baioni, Elena; Petio, Carmine; Raggi, Maria Augusta

    2008-08-29

    A new analytical method, based on liquid chromatography with coulometric detection, has been developed and applied to the determination of selected phenothiazines (chlorpromazine, promazine, fluphenazine and levomepromazine) in human plasma. The drugs were separated on a Discovery pentafluorophenylpropyl column, using a mobile phase composed of acetonitrile (32%) and a pH 1.9 phosphate buffer (68%). Promethazine was used as the internal standard. Detection was carried out at an oxidation potential of +0.500 V. A novel clean-up procedure was developed by means of solid-phase extraction, using cyanopropyl cartridges, which gave good extraction yield for all the analytes, with absolute recovery values higher than 91.0%. The detector response was linear over a plasma concentration range of 0.5-250.0 ng mL(-1) for chlorpromazine, promazine and levomepromazine and of 0.2-4.0 ng mL(-1) for fluphenazine. Precision results, expressed by the intra-day and the inter-day relative standard deviation values, were good, being lower than 3.9%. Accuracy data were satisfactory as well. The method has been successfully applied to the analysis of drug plasma levels of psychiatric patients undergoing therapy with selected phenothiazines. PMID:18706338

  1. Direct detection of Mycobacterium tuberculosis in sputum using combined solid phase extraction-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Dang, Ngoc A; Mourão, Marta; Kuijper, Sjoukje; Walters, Elisabetta; Janssen, Hans-Gerd; Kolk, Arend H J

    2015-04-01

    Recently, thermally-assisted hydrolysis and methylation followed by gas chromatography-mass spectrometry (THM-GC-MS) in combination with chemometrics has been used to develop a 20-compound model for fast differentiation of Mycobacterium tuberculosis (MTB) from Non-tuberculous mycobacteria (NTM) in bacterial cultures. This model provided better than 95% accuracy. In our current work a hexane/methanol/water extraction followed by a solid phase extraction (SPE) clean-up procedure was developed for use before THM-GC-MS, to make the test suitable for the identification of mycobacteria in sputum. The 20 biomarker model had to be adapted since many compounds were also found in the sputum of non-tuberculosis patients. An algorithm was established based on tuberculostearic acid, hexacosanoic acid and mycoserosates. The detection limit of the method was approximately 1×10(4) bacteria/mL sputum. Sputum specimens from 32 patients from South Africa who were suspected of having tuberculosis were blindly tested using the new method. Eight of the nine culture-positive sputum specimens were detected by the new SPE-THM-GC-MS method, resulting in a sensitivity of 89%. The specimen that was missed by the new method was also microscopy negative. The specificity of the test was 100%; all 23 microscopy- and culture-negative specimens were correctly identified as negative by SPE-THM-GC-MS. PMID:25728368

  2. 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)

  3. 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)

  4. Detection of urinary creatinine using gold nanoparticles after solid phase extraction

    Science.gov (United States)

    Sittiwong, Jarinya; Unob, Fuangfa

    2015-03-01

    Label-free gold nanoparticles (AuNPs) were utilized in the detection of creatinine in human urine after a sample preparation by extraction of creatinine on sulfonic acid functionalized silica gel. With the proposed sample preparation method, the interfering effects of the urine matrix on creatinine detection by AuNPs were eliminated. Parameters affecting creatinine extraction were investigated. The aggregation of AuNPs induced by creatinine resulted in a change in the surface plasmon resonance signal with a concomitant color change that could be observed by the naked eye and quantified spectrometrically. The effect of AuNP concentration and reaction time on AuNP aggregation was investigated. The method described herein provides a determination of creatinine in a range of 15-40 mg L-1 with a detection limit of 13.7 mg L-1 and it was successfully used in the detection of creatinine in human urine samples.

  5. Detection of urinary creatinine using gold nanoparticles after solid phase extraction.

    Science.gov (United States)

    Sittiwong, Jarinya; Unob, Fuangfa

    2015-03-01

    Label-free gold nanoparticles (AuNPs) were utilized in the detection of creatinine in human urine after a sample preparation by extraction of creatinine on sulfonic acid functionalized silica gel. With the proposed sample preparation method, the interfering effects of the urine matrix on creatinine detection by AuNPs were eliminated. Parameters affecting creatinine extraction were investigated. The aggregation of AuNPs induced by creatinine resulted in a change in the surface plasmon resonance signal with a concomitant color change that could be observed by the naked eye and quantified spectrometrically. The effect of AuNP concentration and reaction time on AuNP aggregation was investigated. The method described herein provides a determination of creatinine in a range of 15-40mgL(-1) with a detection limit of 13.7mgL(-1) and it was successfully used in the detection of creatinine in human urine samples. PMID:25546357

  6. Micro-column solid phase extraction to determine uranium and thorium in environmental samples

    International Nuclear Information System (INIS)

    Extraction chromatographic separation techniques based on U/TEVA and TEVA resins were utilized to separate uranium and thorium isotopes in complex matrices from environmental samples. This approach has the advantages of ease of quantitative analysis, small sample size, an absence of mixed waste solvents, complete separation of U/Th isotopes, acceptable chemical yields and good energy resolution in the alpha spectrum. The procedure for analyzing alpha-emitting isotopes of uranium and thorium in geothermal water from Peito, Taiwan, is illustrated in detail. It involves sample pre-concentration, filtration and separation by highly selective extraction chromatographic resins, followed by electroplating and alpha-spectroscopy. The analytical results show a chemical recovery exceeding 55% for U and 65% for Th, respectively, under optimized conditions. The efficient and cost-effective use of recyclable columns makes the analytical methods simple, accurate, rapid, reliable and robust

  7. Electrospun polymer nanofibers as a solid-phase extraction sorbent for the determination of trace pollutants in environmental water

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Dongjin; Kang, Xuejun; Chen, Liqin [Southeast University, School of Public Health, Nanjing (China); Zhang, Yiyun; Wei, Hongmei; Gu, Zhongze [Southeast University, State Key Laboratory of Molecular and Biomolecular Electronics, Nanjing (China)

    2008-02-15

    This paper describes the novel preparation of three kinds of nanofibers [poly(styrene-co-methacrylic acid), poly(styrene-co-p-styrene sulfonate), polystyrene] investigated as solid-phase extraction (SPE) sorbents to extract six compounds (nitrobenzene, 2-naphthol, benzene, n-butyl p-hydroxybenzoate, naphthalene, p-dichlorobenzene) in environmental water by high-performance liquid chromatography. Parameters affecting extraction efficiency were investigated in detail to explore the extraction mechanism of the nanofibers. Under optimized conditions, six compounds followed an excellent linear relationship in the range 10-5,000 ng mL{sup -1} with coefficients of determination (r {sup 2}) greater than 0.99. The repeatability (expressed as relative standard deviations) was from 3.0 to 7.0%, corresponding to 2.0 mL of water samples at 25 and 500 ng mL{sup -1} spiked levels for the six compounds. The limits of detection varied from 0.01 to 0.15 ng mL{sup -1} (signal-to-noise ratio of3). A comparison of the SPE using nanofibers as sorbents and the most commonly used octadecylsilica SPE cartridges was carried out in terms of absolute recovery, sensitivity, and reproducibility for the compounds investigated. Finally, the method was applied to four real water samples. The results highlighted the importance of functional groups, and the polarity of nanofibers in controlling sorption of target compounds, and clearly showed that the new method could be a viable and environmentally friendly technique for analyzing pollutants in environmental samples. (orig.)

  8. 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.

  9. 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.

    1039-10-01

    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.

  10. A New Solid Phase Extraction for the Determination of Anthocyanins in Grapes

    Directory of Open Access Journals (Sweden)

    Marta Ferreiro-González

    2014-12-01

    Full Text Available A method for the concentration and cleaning of red grape extracts prior to the determination of anthocyanins by UPLC-DAD has been developed. This method is of special interest in the determination of phenolic maturity as it allows the analysis of the anthocyanins present in grapes. Several different SPE cartridges were assessed, including both C-18- and vinylbenzene-based cartridges. C-18-based cartridges presented a very low retention for the glucosylated anthocyanidins while vinylbenzene-based cartridges showed excellent retention for these compounds. The optimized method involves the initial conditioning of the cartridge using 10 mL of methanol and 10 mL of water, followed by loading of up to 100 mL of red grape extract. Ten mL of water was used in the washing step and anthocyanins were subsequently eluted using 1.5 mL of acidified methanol at pH 2. This method simplifies the determination of individual anthocyanins as, on the one hand, it cleans the sample of interference and, on the other hand, it increases the concentration to up to 25:1.5. The developed method has been validated with a range of different grapes and it has also been tested as a means of determining the different anthocyanins in grapes with different levels of maturity.

  11. 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.

    1086-10-01

    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.

  12. Solid Phase Extraction of Trace Copper(II Using Modified Nano Polyacrylonitrile Fiber

    Directory of Open Access Journals (Sweden)

    A. Moghimi

    2012-07-01

    Full Text Available A simple method has been developed for the preconcentration of copper(II based on the adsorption of its Modified nano polyacrylonitrile fiber. Modified nano polyacrylonitrile fiber (PANF was prepared by adding of acrylic fibers to mSethanolamine (MMA with different concentration solutions. The stability of a chemically Modified nano polyacrylonitrile fiber especially in concentrated hydrochloric acid which was then used as a recycling and pre-concentration reagent for further uses of modified nano polyacrylonitrile fiber. The application of this Modified nano polyacrylonitrile fiber for sorption of a series of metal ions was performed by using different controlling factors such as the pH of metal ion solution and the equilibration shaking time by the static technique. Cu (II was found to exhibit the highest affinity towards extraction by these Modified nano polyacrylonitrile fiber phases. The pronounced selectivity was also confirmed from the determined distribution coefficient (Kd of all the metal ions, showing the highest value reported for Cu (II to occur by Modified nano polyacrylonitrile fiber. The potential applications ofModified nano polyacrylonitrile fiber for selective extraction of Cu(II to occur from aqueous solution were successfully accomplished as well as pre- concentration of low concentration of Cu(II (60 pg ml-1 from natural tap water with a pre-concentration factor of 100 for Cu(II off-line analysis by flame atomic absorption analysis.

  13. 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)

  14. Solid phase extraction of Cu(II as diethyldithiocarbamate (DDTC complex by polyurethane foam

    Directory of Open Access Journals (Sweden)

    Sant'Ana Otoniel D.

    2003-01-01

    Full Text Available This paper presents a study about the sorption of copper-diethyldithiocarbamate complex onto polyurethane foam (PUF. It was observed that the maximum sorption of Cu(II (80 or 150 µg L-1 was verified at pH 6.8 in presence of 4.5 x 10-5 mol L-1 DDTC. The shaking time needed to achieve the equilibrium was 40 minutes. From these data, a kinetic characterization was performed by applying three models, which revealed that a film diffusion process was a rate-determining mechanism. Results also indicated that a ether-like solvent extraction was the sorption mechanism. The investigation of many metallic ions as concomitants showed that the sorption by foam is relatively selective and it can be enhanced by using a suitable masking agent or incrementing the foam mass.

  15. 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

    OpenAIRE

    FELIPE BRAVO; DIEGO GONZALEZ; JULIO BENITES

    2011-01-01

    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, in...

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

    OpenAIRE

    Valente Antonio Luiz Pires; Augusto Fabio; Montero Larisse; Rocha Eduardo Carasek da; Pawliszyn Janusz

    1998-01-01

    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 l...

  17. Development and Validation of a Disk Solid Phase Extraction and Gas Chromatography-Mass Spectrometry Method for MDMA, MDA, HMMA, HMA, MDEA, Methamphetamine and Amphetamine in Sweat

    OpenAIRE

    Martinis, Bruno S.; Barnes, Allan J.; Scheidweiler, Karl B.; Huestis, Marilyn A.

    2007-01-01

    We describe the development and validation of a method for the simultaneous quantification of 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), 3-hydroxy-4-methoxymethamphetamine (HMMA), 3-hydroxy-4-methoxyamphetamine (HMA), 3,4-methylenedioxyethylamphetamine (MDEA), methamphetamine (MAMP) and amphetamine (AMP) in sweat. Drugs were eluted from PharmChek™ sweat patches with sodium acetate buffer, extracted with disk solid phase extraction and analyzed using GC/MS...

  18. A novel magnetic poly(aniline-naphthylamine)-based nanocomposite for micro solid phase extraction of rhodamine B

    International Nuclear Information System (INIS)

    Graphical abstract: -- Highlights: •A Fe3O4–aniline-naphthylamine nanocomposite was prepared via a simple route. •The magnetic nanocomposite was applied for isolation of RhB from water. •The nanocomposite applicability was compared with other pristine polymers. •The method was applied for the determination of RhB in different samples. -- Abstract: A novel Fe3O4–poly(aniline-naphthylamine)-based nanocomposite was synthesized by chemical oxidative polymerization process as a magnetic sorbent for micro solid phase extraction. The scanning electron microscopy images of the synthesized nanocomposite revealed that the copolymer posses a porous structure with diameters less than 50 nm. The extraction efficiency of this sorbent was examined by isolation of rhodamine B, a mutagenic and carcinogenic dye, from aquatic media in dispersion mode. Among different synthesized polymers, Fe3O4/poly(aniline-naphthylamine) nanocomposite showed a prominent efficiency. Parameters including the desorption solvent, amount of sorbent, desorption time, sample pH, ionic strength, extraction time and stirring rate were optimized. Under the optimum condition, a linear spiked calibration curve in the range of 0.35–5.00 ?g L?1 with R2 = 0.9991 was obtained. The limits of detection (3Sb) and limits of quantification (10Sb) of the method were 0.10 ?g L?1 and 0.35 ?g L?1 (n = 3), respectively. The relative standard deviation for water sample with 0.5 ?g L?1 of RhB was 4.2% (n = 5) and the absolute recovery was 92%. The method was applied for the determination of rhodamine B in dishwashing foam, dishwashing liquid, shampoo, pencil, matches tips and eye shadows samples and the relative recovery percentage were in the range of 94–99%

  19. Automated determination of tramadol enantiomers in human plasma using solid-phase extraction in combination with chiral liquid chromatography.

    Science.gov (United States)

    Ceccato, A; Chiap, P; Hubert, P; Crommen, J

    1997-09-26

    A sensitive and automated method for the separation and individual determination of tramadol enantiomers in plasma has been developed using solid-phase extraction (SPE) on disposable extraction cartridges (DECs) in combination with chiral liquid chromatography (LC). The SPE operations were performed automatically by means of a sample processor equipped with a robotic arm (ASPEC system). The DEC filled with ethyl silica (50 mg) was first conditioned with methanol and phosphate buffer, pH 7.4. A 1.0-ml volume of plasma was then applied on the DEC. The washing step was performed with the same buffer. The analytes were eluted with 0.15 ml of methanol, and 0.35 ml of phosphate buffer, pH 6.0, containing sodium perchlorate (0.2 M) were added to the extract before injection into the LC system. The enantiomeric separation of tramadol was achieved using a Chiralcel OD-R column containing cellulose tris-(3,5-dimethylphenylcarbamate) as chiral stationary phase. The mobile phase was a mixture of phosphate buffer, pH 6.0, containing sodium perchlorate (0.2 M) and acetonitrile (75:25). The mobile-phase pH and the NaClO4 concentration were optimized with respect to enantiomeric resolution. The method developed was validated. Recoveries for both enantiomers of tramadol were about 100%. The method was found to be linear in the 2.5-150 ng/ml concentration range [r2=0.999 for (+)- and (-)-tramadol]. The repeatability and intermediate precision at a concentration of 50 ng/ml were 6.5 and 8.7% for (+)-tramadol and 6.1 and 7.6% for (-)-tramadol, respectively. PMID:9367204

  20. A novel magnetic poly(aniline-naphthylamine)-based nanocomposite for micro solid phase extraction of rhodamine B

    Energy Technology Data Exchange (ETDEWEB)

    Bagheri, Habib, E-mail: bagheri@sharif.edu; Daliri, Rasoul; Roostaie, Ali

    2013-09-10

    Graphical abstract: -- Highlights: •A Fe{sub 3}O{sub 4}–aniline-naphthylamine nanocomposite was prepared via a simple route. •The magnetic nanocomposite was applied for isolation of RhB from water. •The nanocomposite applicability was compared with other pristine polymers. •The method was applied for the determination of RhB in different samples. -- Abstract: A novel Fe{sub 3}O{sub 4}–poly(aniline-naphthylamine)-based nanocomposite was synthesized by chemical oxidative polymerization process as a magnetic sorbent for micro solid phase extraction. The scanning electron microscopy images of the synthesized nanocomposite revealed that the copolymer posses a porous structure with diameters less than 50 nm. The extraction efficiency of this sorbent was examined by isolation of rhodamine B, a mutagenic and carcinogenic dye, from aquatic media in dispersion mode. Among different synthesized polymers, Fe{sub 3}O{sub 4}/poly(aniline-naphthylamine) nanocomposite showed a prominent efficiency. Parameters including the desorption solvent, amount of sorbent, desorption time, sample pH, ionic strength, extraction time and stirring rate were optimized. Under the optimum condition, a linear spiked calibration curve in the range of 0.35–5.00 ?g L{sup ?1} with R{sup 2} = 0.9991 was obtained. The limits of detection (3S{sub b}) and limits of quantification (10S{sub b}) of the method were 0.10 ?g L{sup ?1} and 0.35 ?g L{sup ?1} (n = 3), respectively. The relative standard deviation for water sample with 0.5 ?g L{sup ?1} of RhB was 4.2% (n = 5) and the absolute recovery was 92%. The method was applied for the determination of rhodamine B in dishwashing foam, dishwashing liquid, shampoo, pencil, matches tips and eye shadows samples and the relative recovery percentage were in the range of 94–99%.

  1. Solid phase extractive preconcentration of some actinide elements using impregnated carbon

    International Nuclear Information System (INIS)

    Apricot stone shells were carbonized under certain chemical and thermal conditions. The produced sorbent had been impregnated with different concentrations of oxalic and succinic acids. They were physically characterized and used for preconcentration of U(VI) and Th(IV) from acidified aqueous solutions. Batch equilibrium studies revealed that a quantitative preconcentration could be achieved at pH ?2 for U(VI) and ?1.3 for Th(IV). The equilibrium time was extended up to 24h for U(VI) and 40 min for Th(IV). The modified sorbent showed a superior extractability for U(VI) and Th(IV) with distribution coefficient mean values of 2084 and 7808 mL g-1, respectively. The sorption capacity values are 2.39 and 8.47 mg g-1 for U(VI) and Th(IV) sorption onto apricot stone anchored with oxalic acid and 2.3 and 9.18 mg g-1 for sorbent anchored with succinic acid. Desorption of loaded uranium ions was effectively achieved using 1 M HNO3 while only 0.5 M HNO3 was recommended to release retained thorium ions. (author)

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

    Science.gov (United States)

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

    2015-04-15

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

  3. 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

  4. A sheath flow gating interface for the on-line coupling of solid-phase extraction with capillary electrophoresis.

    Science.gov (United States)

    Weng, Qianfeng; Fu, Lianjuan; Li, Xintong; An, Ran; Li, Jinxiang

    2015-02-01

    A sheath flow gating interface (SFGI) is presented for the on-line coupling of solid-phase extraction (SPE) with capillary electrophoresis (CE). The design, construction and operation of the SFGI are described in detail. After operating conditions were investigated and selected, the SFGI was evaluated on a SPE-CE-UV setup using hydroxylated poly(glycidyl methacrylate-co-ethylene dimethacrylate) monolith as the absorbent and using three phenols as the test analytes. The preconcentration factors obtained with the SPE-CE-UV system and the SPE-UV part are 530 and 550, respectively. The plate numbers obtained using the SPE-CE-UV system are slightly better than or comparable to those with the CE-UV part. The precisions (RSDs) of 100 consecutive injections are 2.43%, 3.86%, and 4.25% for peak height, peak area and migration time, respectively. The measured recoveries for the river water samples spiked at three different levels are in the range of 93.6-102.8% with the interday RSD values ranging from 2.0 to 4.5% (n=3). These data collectively demonstrate that the SFGI has the ability to exactly and reproducibly transfer nanoliters of fractions from SPE onto CE with no degradation of the efficiencies of SPE and CE, suggesting a great potential to be routinely used for the coupling of SPE, microcolumn LC or FIA with CE. PMID:25604819

  5. Solid-phase extraction and sample stacking-capillary electrophoresis for the determination of quaternary ammonium herbicides in drinking water.

    Science.gov (United States)

    Núñez, O; Moyano, E; Galceran, M T

    2002-02-01

    Conditions for the simultaneous determination of paraquat, diquat and difenzoquat by capillary zone electrophoresis were established by combining two preconcentration procedures. Off-line solid-phase extraction was used for the isolation and preconcentration of quats in drinking water. Quats were then analysed by capillary electrophoresis using sample stacking with matrix removal as on-column preconcentration procedure. Two different porous graphitic carbon cartridges were compared. The breakthrough volumes of the three herbicides were calculated and the loading capacity of the sorbents was compared. Recoveries higher than 80% for difenzoquat and around 40% for paraquat and diquat were obtained when a sample volume of 250 ml was percolated. For the stacking-capillary electrophoresis analysis of quats, 50 mM acetic acid-ammonium acetate (pH 4.0), 0.8 mM cetyltrimethylammonium bromide with 5% (v/v) methanol as carrier electrolyte was used. Detection limits, based on a signal-to-noise ratio of 3:1, were lower than 0.3 microg l(-1) for standards in Milli-Q water, and lower than 2.2 microg l(-1) for drinking water samples. Run-to-run and day-to-day precision of the method were established. The two preconcentration procedures used together was successfully applied to the analysis of the three herbicides in spiked drinking water at concentrations below the maximum admissible US Environmental Protection Agency levels. PMID:11873975

  6. Analysis of volatile compositions of Magnolia biondii pamp by steam distillation and headspace solid phase micro-extraction.

    Science.gov (United States)

    Zeng, Zhi; Xie, Runqian; Zhang, Tao; Zhang, Han; Chen, Jie Yu

    2011-01-01

    The chemical compositions of volatile components from Magnolia biondii Pamp were determined by steam distillation (SD) and headspace solid phase micro-extraction (HS-SPME) followed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analysis. Fifty-six compounds were identified and the major volatile components were d-camphor (0.18-43.26%), 1,8-cineol (13.23-38.02%), ?-terpineol (6.57-12.29%) and ?-cadinene (5.53-15.15%). The comparison of the volatile components from M. biondii Pamp harvested in three regions of China was investigated. Also, the comparison of volatile components by SD and HS-SPME methods in term of isolation time, plant-consuming and chemical compositions was discussed as well. The percentages of the volatile components by HS-SPME method were found to be large difference from the corresponding one by SD method. HS-SPME technique was much faster than SD (60 min (HS-SPME)/420 min (SD)). Although the aromatic profiles between HS-SPME and SD methods showed several quantitative differences, HS-SPME may be applied routinely to analyze aromatic and medicinal plants. PMID:22123239

  7. 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.

  8. Exploring petroleum hydrocarbons in groundwater by double solid phase extraction coupled to gas chromatography-flame ionization detector.

    Science.gov (United States)

    Pindado Jiménez, Oscar; Pérez Pastor, Rosa Ma; Escolano Segovia, Olga; del Reino Querencia, Susana

    2015-01-01

    This work proposes an analytical procedure for measuring aliphatic and aromatic hydrocarbons fractions present in groundwater. In this method, hydrocarbons are solid phase extracted (SPE) twice from the groundwater and the resulting fractions are analyzed by gas chromatography with flame ionization detection. The first SPE disposes the hydrocarbons present in groundwater in organic solvents and the second SPE divides them into aliphatic and aromatic hydrocarbons. The validation study is carried out and its uncertainties are discussed. Identifying the main sources of uncertainty is evaluated through applying the bottom-up approach. Limits of detection for hydrocarbons ranges are below 5 µg L(-1), precision is not above of 30%, and acceptable recoveries are reached for aliphatic and aromatic fractions studied. The uncertainty due to volume of the sample, factor of calibration and recovery are the highest contributions. The expanded uncertainty range from 13% to 26% for the aliphatic hydrocarbons ranges and from 14% to 23% for the aromatic hydrocarbons ranges. As application, the proposed method is satisfactorily applied to a set of groundwater samples collected in a polluted area where there is evidence to present a high degree of hydrocarbons. The results have shown the range of aliphatic hydrocarbons >C21-C35 is the most abundant, with values ranging from 215 µg L(-1) to 354 µg L(-1), which it is associated to a contamination due to diesel. PMID:25281108

  9. Membrane assisted micro-solid phase extraction of pharmaceuticals with amino and urea-grafted silica gel.

    Science.gov (United States)

    Lim, Tze Han; Hu, Lingna; Yang, Cong; He, Chaobin; Lee, Hian Kee

    2013-11-01

    Individual polar sorbents with surface-displayed amino groups (APS) and non-nucleophilic urea-groups (UPS), were prepared by chemical modification of granular silica gel with bifunctional silane coupling reagents. In this preliminary study, they were separately employed for micro-solid phase extraction (?-SPE) of the quarternary salt of Amitriptyline (Ami), Carbamazepine (Cbz), Ketoprofen (Ket) and Diclofenac (Dfn) from aqueous samples in conjunction with high performance liquid chromatography. The resulting enrichment factors for both APS and UPS are comparable and exceeded those of ?-SPE involving commercial C18-silica gel sorbents. The presence of highly polar, but non-basic and non-nucleophilic surfaces on UPS prompted the development of a UPS-based ?-SPE method. Good linear correlation was found over a concentration range of 0-50 ?g L(-1) with limits of detection ranging from 0.66 to 2.36 ?g L(-1)). Limits of quantification between 1.61 and 7.88 ?g L(-1) were obtained. HPLC analyses indicated that relative recoveries of 123% for Ami, 65.6% for Cbz, 71.2% for Ket and 66.5% for Dfn were obtained during ?-SPE of spiked (10 ?g L(-1)) environmental water samples with percentage relative standard deviations (%RSD) of between 2.1% and 12.6%. PMID:24119709

  10. Polymer microchips integrating solid-phase extraction and high-performance liquid chromatography using reversed-phase polymethacrylate monoliths.

    Science.gov (United States)

    Liu, Jikun; Chen, Chien-Fu; Tsao, Chia-Wen; Chang, Chien-Cheng; Chu, Chin-Chou; DeVoe, Don L

    2009-04-01

    Polymer microfluidic chips employing in situ photopolymerized polymethacrylate monoliths for high-performance liquid chromatography separations of peptides is described. The integrated chip design employs a 15 cm long separation column containing a reversed-phase polymethacrylate monolith as a stationary phase, with its front end seamlessly coupled to a 5 mm long methacrylate monolith which functions as a solid-phase extraction (SPE) element for sample cleanup and enrichment, serving to increase both detection sensitivity and separation performance. In addition to sample concentration and separation, solvent splitting is also performed on-chip, allowing the use of a conventional LC pump for the generation of on-chip nanoflow solvent gradients. The integrated platform takes advantage of solvent bonding and a novel high-pressure needle interface which together enable the polymer chips to withstand internal pressures above 20 MPa (approximately 2900 psi) for efficient pressure-driven HPLC separations. Gradient reversed-phase separation of fluorescein-labeled model peptides and BSA tryptic digest are demonstrated using the microchip HPLC system. Online removal of free fluorescein and enrichment of labeled proteins are simultaneously achieved using the on-chip SPE column, resulting in a 150-fold improvement in sensitivity and a 10-fold reduction in peak width in the following microchip gradient LC separation. PMID:19267447

  11. 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.

  12. Characterization and application of SuperLigR 620 solid phase extraction resin for automated process monitoring of 90Sr

    International Nuclear Information System (INIS)

    Characterization of SuperLigR 620 solid phase extraction resin was performed in order to develop an automated on-line process monitor for 90Sr. The main focus was on strontium separation from barium, with the goal of developing an automated separation process for 90Sr in high-level wastes. High-level waste contains significant 137Cs activity, of which 137mBa is of great concern as an interference to the quantification of strontium. In addition barium, yttrium and plutonium were studied as potential interferences to strontium uptake and detection. A number of complexants were studied in a series of batch Kd experiments, as SuperLigR 620 was not previously known to elute strontium in typical mineral acids. The optimal separation was found using a 2 M nitric acid load solution with a strontium elution step of ?0.49 M ammonium citrate and a barium elution step of ?1.8 M ammonium citrate. 90Sr quantification of Hanford high-level tank waste was performed on a sequential injection analysis microfluidics system coupled to a flow-cell detector. The results of the on-line procedure are compared to standard radiochemical techniques in this paper. (author)

  13. 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)

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

  15. 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

  16. Poly(methyloctylsiloxane) immobilized on silica as a sorbent for solid-phase extraction of some pesticides.

    Science.gov (United States)

    Vigna, Camila R M; Morais, Lais S R; Collins, Carol H; Jardim, Isabel C S F

    2006-05-12

    A laboratory-made sorbent for solid-phase extraction (SPE) was obtained by thermal immobilization of poly(methyloctylsiloxane) (PMOS) onto silica. Cartridges packed with the new sorbent were used for the simultaneous determination of imazethapyr, nicosulfuron, diuron, linuron and chlorimuron-ethyl in water. These pesticides were separated and quantified using high-performance liquid chromatography with diode array detection (HPLC-DAD). The recoveries achieved with the laboratory-made PMOS cartridges were compared with those of some commercially available silica-based and polymer-based cartridges having C18, C8 and NH(2) pendant groups. Method validation using the laboratory-made sorbent was performed for the five pesticides at three fortifications levels (1x, 2x and 10x the limit of quantification of each pesticide). The laboratory-made PMOS cartridge has low cost preparation and showed good recoveries (72-111%) for all pesticides. Repeatability and intermediate precision were lower than 15%. Its performance was similar or even better, in some cases, than those of the commercial cartridges. PMID:16600261

  17. Determination of colloidally-associated polycyclic aromatic hydrocarbons (PAHs) in fresh water using C18 solid phase extraction disks

    International Nuclear Information System (INIS)

    A new application of reversed-phase octadecyl (C18) solid phase extraction disks has been developed to separate the colloidally-associated polycyclic aromatic hydrocarbons (PAHs) from those that were truly dissolved in the samples of fresh water. A correction for the retention of small amounts of colloidal material on the C18 disks was required, which would have otherwise lead to minor underestimates in the degree of partitioning between the two phases. Using the humic substance Aldrich Humic Acid (AHA) as a model colloid and the 16 PAHs on the US Enrivonmental Protection Agency priority pollutant list, the partitioning coefficients of the PAHs between the colloidal and truly dissolved phases were shown to be proportional to the hydrophobicity of the PAHs, as measured by their octanol water partition coefficients (Kow). The values for the partition coefficients obtained (cKdoc') were similar to those previously reported in the literature using alternative methods, confirming that the technique was producing acceptable results. The technique allows the in situ partitioning of PAHs between the truly dissolved and colloidal phases in fresh water bodies to be determined. It will provide an invaluable cross-check of the laboratory-based methods which often require substantial manipulation of the sample and potentially alter the partitioning between the phases

  18. 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 extraction with stable isotope dilution analysis LC-MS/MS and found to be in good agreement. The developed SPE-HPLC online system with fluorescence detection allows a reliable, accurate, and sensitive quantification (limit of quantification, 30 ?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

  19. Novel solid-phase membrane tip extraction and gas chromatography with mass spectrometry methods for the rapid analysis of triazine herbicides in real waters.

    Science.gov (United States)

    Sanagi, Mohd Marsin; Muhammad, Sarmad S; Hussain, Iqbal; Ibrahim, Wan Aini Wan; Ali, Imran

    2015-02-01

    Novel, fast, selective, eco-friendly and reproducible solid-phase membrane tip extraction and gas chromatography with mass spectrometry methods were developed and validated for the analysis of triazine herbicides (atrazine and secbumeton) in stream and lake waters. The retention times of atrazine and secbumeton were 7.48 and 8.51 min. The solid-phase membrane tip extraction was carried out in semiautomated dynamic mode on multiwall carbon nanotubes enclosed in a cone-shaped polypropylene membrane cartridge. Acetone and methanol were found as the best preconditioning and desorption solvents, respectively. The extraction and desorption times for these herbicides were 15.0 and 10.0 min, respectively. The percentage recoveries of atrazine and secbumeton were 88.0 and 99.0%. The linearity range was 0.50-80.0 ?g/L (r(2) > 0.994), with detection limits (membrane tip extraction made these methods novel. The Solid-phase membrane tip extraction method was optimized by considering the effect of extraction time, desorbing solvents and time. PMID:25421899

  20. Solid phase extraction of Cu(II) as diethyldithiocarbamate (DDTC) complex by polyurethane foam

    Scientific Electronic Library Online (English)

    Otoniel D., Sant' Ana; Luciene S., Jesuino; Ricardo J., Cassella; Marcelo S., Carvalho; Ricardo E., Santelli.

    2003-10-01

    Full Text Available Neste trabalho é apresentado um estudo referente à sorção do complexo cobre-dietilditiocarbamato, empregando espuma de poliuretano (EPU) como fase sólida. Foi observado que em pH 6,8 e na presença de DDTC 4,5 x 10-5 mol L-1 a sorção de Cu(II) (80 ou 150 µg L-1) foi máxima. O tempo requerido para que [...] o equilíbrio fosse alcançado foi de 40 min. A partir dos dados deste experimento foi realizada uma caracterização cinética através da aplicação de três modelos, que revelaram que a difusão do complexo na interface entre sólido-líquido foi a etapa determinante na velocidade do processo sortivo. Pôde-se também afirmar que a sorção do complexo se dá através de um mecanismo similar aquele observado em extração líquido-líquido, usando éter como solvente. Testes com possíveis interferentes demonstraram a relativa seletividade da extração do complexo metálico, que pode ser melhorada com a presença de um agente mascarante adequado. Abstract in english This paper presents a study about the sorption of copper-diethyldithiocarbamate complex onto polyurethane foam (PUF). It was observed that the maximum sorption of Cu(II) (80 or 150 µg L-1) was verified at pH 6.8 in presence of 4.5 x 10-5 mol L-1 DDTC. The shaking time needed to achieve the equilibri [...] um was 40 minutes. From these data, a kinetic characterization was performed by applying three models, which revealed that a film diffusion process was a rate-determining mechanism. Results also indicated that a ether-like solvent extraction was the sorption mechanism. The investigation of many metallic ions as concomitants showed that the sorption by foam is relatively selective and it can be enhanced by using a suitable masking agent or incrementing the foam mass.

  1. 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)

  2. 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.

  3. Novel molecularly imprinted polymers based on multi-walled carbon nanotubes with binary functional monomer for the solid-phase extraction of erythromycin from chicken muscle.

    Science.gov (United States)

    Zhang, Zhaohui; Yang, Xiao; Zhang, Huabin; Zhang, Minlei; Luo, Lijuan; Hu, Yufang; Yao, Shouzhuo

    2011-06-01

    A new surface imprinting technique was reported to synthesize multi-walled carbon nanotubes-molecularly imprinted polymers (MWNTs-MIPs) using erythromycin as the template, acryloyl-?-cyclodextrin (acryloyl-?-CD) and methacrylic acid (MAA) as the binary functional monomers. The MWNTs-MIPs were characterized by transmission electron microscopy (TEM), scanning electron micrograph (SEM) and Fourier transform-infrared spectroscopy (FT-IR). Adsorption experiments indicated the MWNTs-MIPs prepared with acryloyl-?-CD and MAA have high selective for erythromycin. The feasibility of the MWNTs-MIPs as solid-phase extraction (SPE) sorbent was evaluated, and the results showed that it can selectively extract erythromycin from chicken muscle samples with the recoveries ranging from 85.3% to 95.8%. The molecularly imprinted solid-phase extraction (MISPE) method could be applied for preconcentration and purification of erythromycin from chicken muscle samples. PMID:21498135

  4. 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

  5. Pharmaceuticals in the freshwater invertebrate, Gammarus pulex, determined using pulverised liquid extraction, solid phase extraction and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Miller, Thomas H; McEneff, Gillian L; Brown, Rebecca J; Owen, Stewart F; Bury, Nicolas R; Barron, Leon P

    2015-04-01

    The development, characterisation and application of a new analytical method for multi-residue PPCP determination in the freshwater amphipod, Gammarus pulex are presented. Analysis was performed using pulverised liquid extraction (PuLE), solid phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Qualitative method performance offered excellent limits of detection at diazepam, nimesulide, trimethoprim and warfarin were determined in G. pulex samples at low ng g(-1) (dry weight) concentrations across these sites. Temazepam and diclofenac were also detected, but were not quantifiable. Six pharmaceuticals were quantified in surface waters across the eight sites at concentrations ranging from 3 to 344 ng L(-1). The possibility for confirmatory detection and subsequent quantification of pharmaceutical residues in benthic organisms such as G. pulex will enable further understanding on the susceptibility and ecological effects of PPCPs in the aquatic environment. PMID:25544334

  6. 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.

  7. 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.

    1701-17-01

    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.

  8. Multi-component analysis of polar water pollutants using sequential solid-phase extraction followed by LC-ESI-MS.

    Science.gov (United States)

    Loos, Robert; Hanke, Georg; Eisenreich, Steven J

    2003-06-01

    A multi-component screening analysis method for polar to medium-polar water pollutants was developed. Sample clean-up and group separation are performed by sequential solid-phase extraction (SSPE) using automated SPE with C18 and polymeric sorbent materials. Analyses are performed by liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS) using a single-quadrupole instrument. More than 90 priority compounds of environmental interest--comprising the most important chemical and substance classes: phenols, carboxylic acids, aromatic sulfonates, aromatic amines, pharmaceuticals, surfactants, dyes, and pesticides--have been chosen for the experiments. The compounds are divided by the SSPE procedure into 3 different polarity classes. The extraction recoveries were determined in the 3 fractions for every single substance, and were for most of the analytes in the range of 50-100%. A mixture of hexane-dichloromethane was used for the elution of nonpolar compounds like alkylphenols from C18. Methanol and acetone are well suited for the elution of more polar substances. The limits of detection (LODs) were determined for all compounds. Effluents from municipal and industrial wastewater treatment plants (WWTPs) treating waste water from textile industries; and the corresponding receiving waters (rivers and lakes) have been analysed with the developed method. Urban and industrial pollution was observed in rivers and streams in the area north of Milan, Italy. In the water samples different phenols (nitrophenols, bisphenol A, nonylphenol), alkylphenol ethoxylate surfactants, their metabolites with endocrine disrupting potential, aromatic sulfonates, linear alkylbenzenesulfonate surfactants, dyes, pesticides, pharmaceuticals, and a dichlorobenzidine compound were identified. PMID:12833980

  9. 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.

  10. 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)

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. Polímeros de impressão molecular obtidos através de polimerização por precipitação e sua aplicação na técnica de extração em fase sólida / Molecularly imprinted polymers prepared by precipitation polymerization and their application to solid phase extraction

    Scientific Electronic Library Online (English)

    Bruna Rachel de B., Peçanha; Luiza R. S., Dias; Eliani, Spinelli; Estela M. F., Muri.

    Full Text Available Polímeros de impressão molecular (Molecularly Imprinted Polymers, MIPs) foram sintetizados e aplicados como adsorventes na técnica de extração em fase sólida (EFS). O método de polimerização por precipitação foi usado para sintetizar os polímeros, devido à simplicidade de preparo, altos rendimentos [...] e obtenção de partículas mais uniformes uma vez que o polímero não é triturado. Os MIPs foram sintetizados com ácido metacrílico como monômero funcional, trimetacrilato de trimetilolpropano como agente de reticulação e cloridrato de amilorida como molécula molde. O solvente de elevada polaridade empregado na síntese (THF:MeOH:H2O) possibilita empregar a técnica para moléculas polares como o cloridrato de amilorida. O controle no volume de solvente permitiu obter partículas maiores, de modo que a EFS foi realizada nas condições usuais, o que confere um potencial para aplicação dessa técnica de polimerização na preparação de adsorventes para EFS. Abstract in english Molecularly imprinted polymers (MIPs) were synthesized and applied as adsorbents in the solid-phase extraction (SPE) technique. The polymers were synthesized by precipitation polymerization because of its simplicity, high yields and good control of final particle size. MIPs were synthesized using me [...] thacrylic acid as functional monomer, trimethylolpropane trimethacrylate as crosslinker and amiloride hydrochloride as template. The polar solvent mixture used (THF:MeOH:H2O) permitted polar molecules such as amiloride hydrochloride to be used. The solvent volume control allowed bigger particles to be formed, so that the solid-phase extraction technique could be employed under usual conditions, and therefore this polymerization technique is promising for preparing adsorbents for SPE.

  16. An absorbing microwave micro-solid-phase extraction device used in non-polar solvent microwave-assisted extraction for the determination of organophosphorus pesticides

    Energy Technology Data Exchange (ETDEWEB)

    Wang Ziming, E-mail: wangziming@jlu.edu.cn [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); College of Environment and Resources, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Zhao Xin; Xu Xu; Wu Lijie; Su Rui; Zhao Yajing; Jiang Chengfei; Zhang Hanqi [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Ma Qiang [Chinese Academy of Inspection and Quarantine, Beijing 100123 (China); Lu Chunmei [College of Technology Center, Jilin Entry-Exit Inspection and Quarantine Bureau, Changchun 130062 (China); Dong Deming [College of Environment and Resources, Jilin University, 2699 Qianjin Street, Changchun 130012 (China)

    2013-01-14

    Highlights: Black-Right-Pointing-Pointer An absorbing microwave {mu}-SPE device packed with activated carbon was used. Black-Right-Pointing-Pointer Absorbing microwave {mu}-SPE device was made and used to enrich the analytes. Black-Right-Pointing-Pointer Absorbing microwave {mu}-SPE device was made and used to heat samples directly. Black-Right-Pointing-Pointer MAE-{mu}-SPE was applied to the extraction of OPPs with non-polar solvent only. - Abstract: A single-step extraction-cleanup method, including microwave-assisted extraction (MAE) and micro-solid-phase extraction ({mu}-SPE), was developed for the extraction of ten organophosphorus pesticides in vegetable and fruit samples. Without adding any polar solvent, only one kind of non-polar solvent (hexane) was used as extraction solvent in the whole extraction step. Absorbing microwave {mu}-SPE device, was prepared by packing activated carbon with microporous polypropylene membrane envelope, and used as not only the sorbent in {mu}-SPE, but also the microwave absorption medium. Some experimental parameters effecting on extraction efficiency was investigated and optimized. 1.0 g of sample, 8 mL of hexane and three absorbing microwave {mu}-SPE devices were added in the microwave extraction vessel, the extraction was carried out under 400 W irradiation power at 60 Degree-Sign C for 10 min. The extracts obtained by MAE-{mu}-SPE were directly analyzed by GC-MS without any clean-up process. The recoveries were in the range of 93.5-104.6%, and the relative standard deviations were lower than 8.7%.

  17. Determination of sulfonamides in serum by on-line solid-phase extraction coupled to liquid chromatography with photoinduced fluorescence detection.

    Science.gov (United States)

    Arroyo-Manzanares, Natalia; Lara, Francisco J; Airado-Rodríguez, Diego; Gámiz-Gracia, Laura; García-Campaña, Ana M

    2015-06-01

    An analytical method based on on-line solid-phase extraction coupled to liquid chromatography with photoinduced fluorescence detection has been developed to determine sulfonamides in serum. A home-made setup was used to percolate 3mL of sample through a solid-phase extraction column. Analytes were retained onto the sorbent by an anion exchange mechanism which ensures an optimum compatibility with the subsequent chromatographic separation using a C-18 column and an on-line photoreactor in order to derivatize sulfonamides, which do not present native fluorescence. The method allowed the determination of 7 sulfonamides in serum samples previously deproteinized in less than 18min and with limits of detection ranging between 1.8 and 3.6mg/L. Relative recoveries between 91.5% and 102.1% were obtained with satisfactory precision since relative standard deviations were always below 10.5%. PMID:25863399

  18. On-line ion-pair solid-phase extraction-liquid chromatography-mass spectrometry for the analysis of quaternary ammonium herbicides.

    Science.gov (United States)

    Castro, R; Moyano, E; Galceran, M T

    2000-02-11

    An ion-pair on-line solid-phase extraction procedure using C8 extraction disks, suitable for liquid chromatography-mass spectrometry analysis is developed to determine quaternary ammonium herbicides (quats) in water samples. The separation of these compounds was performed using ion-pair chromatography with heptafluorobutyric acid (15 mM, pH 3.3) and acetonitrile gradient elution. Detection was carried out using a quadrupole mass spectrometer. Water sample volumes up to 50 ml can be preconcentrated with recoveries higher than 70%. Good precision and accuracy (day-to-day and run-to-run) were obtained and the detection limits ranged from 6 to 85 ng l(-1). The proposed on-line ion-pair solid-phase method enables compliance with European Community directives for drinking waters (100 ng l(-1)). PMID:10720257

  19. Analysis of trace Fe in sea water by using inductively coupled plasma mass spectrometry with solid phase chelate extraction technique

    International Nuclear Information System (INIS)

    Field experiments on recovering from barren sea ground called 'Isoyake' by providing Fe in sea water to restore seaweed beds on barren ground, has been carried out. Fe supply source, a mixture of steelmaking slag and compost (humic wood chips), were laid underground in shoreline. A certain amount of restoration of seaweed beds has been confirmed at the locations for several years. Quantitative determination of trace amount of Fe in sea water in necessary to validate the effect of iron source. However, to analyze dissolved Fe in sea water was difficult due to its trace concentration and the interference by high concentration of salts in the analytical samples. We established new analysis method of Fe in sea water, by treating sea water with solid phase chelate extraction and analyzed by inductively coupled plasma mass spectrometry with cool plasma condition. This method was successfully applied for the sea water sample taken from experimental site. Other water quality parameters in the experimental site were also investigated. Fe concentration was significantly highest around the Fe supply source and was decreased with the distance. Although the concentrations of dissolved silica, Mg and Ca were correlated to electrical conductivity of the sample water, Fe concentration was not. According to those results, the concentration of dissolved Fe from steelmaking slag was confirmed, and Fe might be contiguously supplied to the sea water from Fe supply source and promoted the er from Fe supply source and promoted the growth of seaweeds. Therefore, applying a mixture of steelmaking slag and compost as Fe supply source is an effective technique to supply dissolved iron to Isoyake area. (author)

  20. Solid phase extraction-liquid chromatography (SPE-LC) interface for automated peptide separation and identification by tandem mass spectrometry

    Science.gov (United States)

    Hørning, Ole Bjeld; Theodorsen, Søren; Vorm, Ole; Jensen, Ole Nørregaard

    2007-12-01

    Reversed-phase solid phase extraction (SPE) is a simple and widely used technique for desalting and concentration of peptide and protein samples prior to mass spectrometry analysis. Often, SPE sample preparation is done manually and the samples eluted, dried and reconstituted into 96-well titer plates for subsequent LC-MS/MS analysis. To reduce the number of sample handling stages and increase throughput, we developed a robotic system to interface off-line SPE to LC-ESI-MS/MS. Samples were manually loaded onto disposable SPE tips that subsequently were connected in-line with a capillary chromatography column. Peptides were recovered from the SPE column and separated on the RP-LC column using isocratic elution conditions and analysed by electrospray tandem mass spectrometry. Peptide mixtures eluted within approximately 5 min, with individual peptide peak resolution of ~7 s (FWHM), making the SPE-LC suited for analysis of medium complex samples (3-12 protein components). For optimum performance, the isocratic flow rate was reduced to 30 nL/min, producing nanoelectrospray like conditions which ensure high ionisation efficiency and sensitivity. Using a modified autosampler for mounting and disposing of the SPE tips, the SPE-LC-MS/MS system could analyse six samples per hour, and up to 192 SPE tips in one batch. The relatively high sample throughput, medium separation power and high sensitivity makes the automated SPE-LC-MS/MS setup attractive for proteomics experiments as demonstrated by the identification of the components of simple protein mixtures and of proteins recovered from 2DE gels.

  1. 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.

  2. 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; ALOthman, Zeid A.; Mohammad Abulhassan Abdalla; Ayoub A. ALqadami

    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 ...

  3. 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.; 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...

  4. Comprehensive automation of the solid phase extraction gas chromatographic mass spectrometric analysis (SPE-GC/MS) of opioids, cocaine, and metabolites from serum and other matrices

    OpenAIRE

    Lerch, Oliver; Temme, Oliver; Daldrup, Thomas

    2014-01-01

    The analysis of opioids, cocaine, and metabolites from blood serum is a routine task in forensic laboratories. Commonly, the employed methods include many manual or partly automated steps like protein precipitation, dilution, solid phase extraction, evaporation, and derivatization preceding a gas chromatography (GC)/mass spectrometry (MS) or liquid chromatography (LC)/MS analysis. In this study, a comprehensively automated method was developed from a validated, partly automated routine method...

  5. Solid-Phase Micro-Extraction (SPME) in the early detection of potentially active volatile compounds from organic wastes used for the management of soil-borne pathogens

    OpenAIRE

    Fuente, E. La; Di?ez-rojo, M. A.; Soria, A. C.; Garci?a-a?lvarez, A.; Piedra Buena, A.; Almendros, G.; Bello, A.

    2009-01-01

    The complex molecular assemblages were analysed in the soil gas phase after applying pine forest wastes (PFW) or sugarbeet vinasses (SBV) for soil-borne crop pests management. For this purpose, solid-phase micro-extraction (SPME) and gas chromatography (GC) were used coupled with mass spectrometry (MS). The organic wastes were applied either to Calcic Entisol or Haplic Arenosol moistened at field capacity and soil was covered with polyethylene sheet for 28-30 days to retain the ...

  6. A Method for Multiple Mycotoxin Analysis in Wines by Solid Phase Extraction and Multifunctional Cartridge Purification, and Ultra-High-Performance Liquid Chromatography Coupled to Tandem Mass Spectrometry

    OpenAIRE

    Naoki Mochizuki; Masayoshi Tamura; Atsuo Uyama; Ayumi Takahashi

    2012-01-01

    An analytical method using two solid phase extractions and ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) was developed for the identification and quantification of 14 mycotoxins (patulin, deoxynivalenol, aflatoxins B1, B2, G1, G2, M1, T-2 toxin, HT-2 toxin, zearalenone, fumonisins B1, B2

  7. The use of under-loaded C18 solid-phase extraction plates increases reproducibility of analysis of tryptic peptides from unfractionated human plasma

    OpenAIRE

    Guo, Xiaofeng; Kristal, Bruce S.

    2012-01-01

    Bottom-up proteomics requires the digestion of proteins into peptides by processes that use salts for denaturing and buffering purposes. These salts need to be removed prior to mass spectrometry analysis to reduce ion-suppression; solid phase extraction (SPE) is a commonly used strategy. There are many commercially-available SPE sorbent types and sizes, which are generally provided with manufacturer recommendations for use, including protein loading capacity. We found that these general sugge...

  8. Isolation of bound residues of nitrofuran drugs from tissue by solid-phase extraction with determination by liquid chromatography with UV and tandem mass spectrometric detection

    OpenAIRE

    Conneely, A.; Nugent, A.; O Keeffe, M.; Mulder, P. P. J.; Rhijn, J. A.; Kovacsics, L.; Fodor, A.; Mccracken, R. J.; Kennedy, D. G.

    2003-01-01

    Use of nitrofuran drugs in food-producing animals has been prohibited within the EU because they may represent a public health risk. Monitoring compliance with the ban has focused on the detection of protein-bound nitrofuran metabolites which, in contrast to the parent compounds, are stable and persist in animal tissues. This paper describes a solid phase extraction clean-up procedure for the protein-bound metabolite of furazolidone, 3-amino-2-oxazolidone (AOZ), allowing detection of the deri...

  9. 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

  10. 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)

  11. 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...

  12. Fast and easy multiresidue method employing acetonitrile extraction/partitioning and "dispersive solid-phase extraction" for the determination of pesticide residues in produce.

    Science.gov (United States)

    Anastassiades, Michelangelo; Lehotay, Steven J; Stajnbaher, Darinka; Schenck, Frank J

    2003-01-01

    A simple, fast, and inexpensive method for the determination of pesticide residues in fruits and vegetables is introduced. The procedure involves initial single-phase extraction of 10 g sample with 10 mL acetonitrile, followed by liquid-liquid partitioning formed by addition of 4 g anhydrous MgSO4 plus 1 g NaCl. Removal of residual water and cleanup are performed simultaneously by using a rapid procedure called dispersive solid-phase extraction (dispersive-SPE), in which 150 mg anhydrous MgSO4 and 25 mg primary secondary amine (PSA) sorbent are simply mixed with 1 mL acetonitrile extract. The dispersive-SPE with PSA effectively removes many polar matrix components, such as organic acids, certain polar pigments, and sugars, to some extent from the food extracts. Gas chromatography/mass spectrometry (GC/MS) is then used for quantitative and confirmatory analysis of GC-amenable pesticides. Recoveries between 85 and 101% (mostly > 95%) and repeatabilities typically pesticides, including very polar and basic compounds such as methamidophos, acephate, omethoate, imazalil, and thiabendazole. Using this method, a single chemist can prepare a batch of 6 previously chopped samples in < 30 min with approximately 1 dollar (U.S.) of materials per sample. PMID:12723926

  13. Dynamic microwave-assisted extraction coupled on-line with solid-phase extraction and large-volume injection gas chromatography: determination of organophosphate esters in air samples.

    Science.gov (United States)

    Ericsson, Magnus; Colmsjö, Anders

    2003-04-01

    An on-line method was developed for the extraction, cleanup, and analysis of airborne organophosphate esters collected on glass fiber filters. The extraction and cleanup step was performed by conducting the dynamic microwave-assisted extraction (DMAE) coupled to solid-phase extraction (SPE). This system was further connected to include large-volume injection gas chromatography. The Injection interface was a programmable temperature vaporizer. The system performance test was investigated using spiked glass fiber filters. The DMAE-SPE recovery of the organophosphate esters was found to be greater than 97%. The repeatability of the uncorrected peak areas and the retention times was determined to be 4.2-8.0 and 0.03% relative standard deviation, respectively, and limits of detection were in the range 61-186.2 pg/m3. The method was tested in a newly restored office, in which several of the targeted organophosphate esters were detected. The total sampling and analysis time was less than 1.5 h. PMID:12705607

  14. The determination of organochlorine pesticides based on dynamic microwave-assisted extraction coupled with on-line solid-phase extraction of high-performance liquid chromatography

    International Nuclear Information System (INIS)

    A rapid technique based on dynamic microwave-assisted extraction coupled with on-line solid-phase extraction of high-performance liquid chromatography (DMAE-SPE-HPLC) has been developed. A TM010 microwave resonance cavity built in the laboratory was applied to concentrate the microwave energy. The sample placed in the zone of microwave irradiation was extracted with 95% acetonitrile (ACN) aqueous solution which was driven by a peristaltic pump at a flow rate of 1.0 mL min-1. The extraction can be completed in a recirculating system in 10 min. When a number of extraction cycles were completed, the extract (1 mL) was diluted on-line with water. Then the extract was loaded into an SPE column where the analytes were retained while the unretained matrix components were washed away. Subsequently, the analytes were automatically transferred from the SPE column to the analytical column and determined by UV detector at 238 nm. The technique was used for determination of organochlorine pesticides (OCPs) in grains, including wheat, rice, corn and bean. The limits of detection of OCPs are in the range of 19-37 ng g-1. The recoveries obtained by analyzing the four spiked grain samples are in the range of 86-105%, whereas the relative standard deviation (R.S.D.) values are <8.7% ranging from 1.2 to 8.7%. Our method was demonstrated to be fast, accurate, and precise. In addition, only small quantities of solvent and sample were requiredent and sample were required

  15. Quantification by solid phase micro extraction and stable isotope dilution assay of norisoprenoid compounds in red wines obtained from Piedmont rare varieties.

    Science.gov (United States)

    Petrozziello, Maurizio; Borsa, Daniela; Guaita, Massimo; Gerbi, Vincenzo; Bosso, Antonella

    2012-12-15

    A method to identify and quantify megastigmane norisoprenoid compounds in wines was developed using headspace solid phase micro extraction (SPME) coupled with gas-chromatography/mass-spectrometry (GC-MS). Three different compounds were quantified by stable isotope dilution assay (SIDA): ?-damascenone, ?-ionone and ?-ionone. Particular attention was paid to maximising the method's sensitivity while reducing the extraction time. To optimise the extraction conditions, a statistically designed experiment was performed using extraction time, extraction temperature and ethanol content as operating variables. Five different SPME fibres suitable for the analysis of volatile compounds were compared. This study confirmed that the PDMS/DVB coating performs best for the quantification of ?-damascenone and ?-ionone, and the crucial influence of ethanol content of the sample on extraction effectiveness. Finally, the optimised method was applied to the study of various wines derived from rare and autochthonous grape varieties of north-western Italy. PMID:22980832

  16. 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.

  17. 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.

  18. 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)

  19. Comparison of different extraction methods for the determination of essential oils and related compounds from aromatic plants and optimization of solid-phase microextraction/gas chromatography.

    Science.gov (United States)

    Richter, Jana; Schellenberg, Ingo

    2007-03-01

    Different extraction methods for the subsequent gas chromatographic determination of the composition of essential oils and related compounds from marjoram (Origanum majorana L.), caraway (Carum carvi L.), sage (Salvia officinalis L.), and thyme (Thymus vulgaris L.) have been compared. The comparison was also discussed with regard to transformation processes of genuine compounds, particularly in terms of expenditure of time. Hydrodistillation is the method of choice for the determination of the essential oil content of plants. For investigating the composition of genuine essential oils and related, aroma-active compounds, hydrodistillation is not very useful, because of discrimination and transformation processes due to high temperatures and acidic conditions. With cold solvent extraction, accelerated solvent extraction, and supercritical fluid extraction, discrimination of high and non-volatile aroma-active components as well as transformation processes can be diminished, but non-aroma-active fats, waxes, or pigments are often extracted, too. As solid-phase microextraction is a solvent-free fully automizable sample preparation technique, this was the most sparing to sensitive components and the most time-saving method for the rapid determination of the aroma compounds composition in marjoram, caraway, sage, and thyme. Finally, solid-phase microextraction could be successfully optimized for the extraction of the aroma components from the plants for their subsequent gas chromatographic determination. PMID:17221240

  20. On-line coupling of dynamic microwave-assisted extraction to solid-phase extraction for the determination of sulfonamide antibiotics in soil.

    Science.gov (United States)

    Chen, Ligang; Zeng, Qinglei; Wang, Hui; Su, Rui; Xu, Yang; Zhang, Xiaopan; Yu, Aimin; Zhang, Hanqi; Ding, Lan

    2009-08-26

    A rapid technique based on dynamic microwave-assisted extraction (DMAE) coupled on-line with solid-phase extraction (SPE) was developed for the determination of sulfonamides (SAs) including sulfadiazine, sulfameter, sulfamonomethoxine and sulfaquinoxaline in soil. The SAs were first extracted with acetonitrile under the action of microwave energy, and then directly introduced into the SPE column which was packed with neutral alumina for preconcentration of analytes and clean-up of sample matrix. Subsequently, the SAs trapped on the alumina were eluted with 0.3% acetic acid aqueous solution and determined by liquid chromatography-tandem mass spectrometry. The DMAE parameters were optimized by the Box-Behnken design. Maximum extraction efficiency was achieved using 320 W of microwave power; 12 mL of extraction solvent and 0.8 mL min(-1) of extraction solvent flow rate. The limits of detection and quantification obtained are in the range of 1.4-4.8 ng g(-1) and 4.6-16.0 ng g(-1) for the SAs, respectively. The mean values of relative standard deviation of intra- and inter-day ranging from 2.7% to 5.3% and from 5.6% to 6.7% are obtained, respectively. The recoveries of SAs obtained by analyzing four spiked soil samples at three fortified levels (20 ng g(-1), 100ngg(-1) and 500 ng g(-1)) were from 82.6+/-6.0% to 93.7+/-5.5%. The effect of standing time of spiked soil sample on the SAs recoveries was examined. The recoveries of SAs decreased from (86.3-101.9)% to (37.6-47.5)% when the standing time changed from one day to four weeks. PMID:19646585

  1. Analysis of some Chlorinated Pesticides in Jordanian Ground- and Surface Waters by Solid-Phase Extraction and Mass Spectrometric Detection- A Method development

    OpenAIRE

    Shahin, Lara

    2004-01-01

    A solid-phase extraction (SPE) method was developed for the determination of organochlorine pesticides, namely aldrin, alpha-BHC, beta-BHC, delta-BHC, dieldrin, endosulfan I, endosulfan II, endosulfan sulfate, endrin, endrin aldehyde, lindane, heptachlor, heptachlor epoxide, 4,4’-DDD, 4,4’-DDE and 4,4’- DDT in water. The effect of extraction conditions, such as the addition of sodium chloride and methanol to the sample prior to loading was studied. The sample was concentrated by a plain...

  2. 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.

  3. Solid-phase extraction approach for phospholipids profiling by titania-coated silica microspheres prior to reversed-phase liquid chromatography-evaporative light scattering detection and tandem mass spectrometry analysis.

    Science.gov (United States)

    Bian, Juan; Xue, Yun; Yao, Kai; Gu, Xue; Yan, Chao; Wang, Yan

    2014-06-01

    A novel strategy for selectively adsorbing phospholipids (PLs) on titania-coated silica core-shell microspheres (TiO2/SiO2) was developed. The TiO2/SiO2 microspheres were prepared through water-vapor-induced internal hydrolysis and then characterized by SEM, UV-vis spectroscopy, X-ray diffraction, and measurements of Brunauer-Emmett-Teller surface area. Analyses showed that the titania layer was uniformly distributed onto the surface of silica particles. The TiO2/SiO2 microspheres were employed as sorbent in solid-phase extraction (SPE), and their absorptive ability was investigated by reversed-phase liquid chromatography-evaporative light scattering detection (RPLC-ELSD). Important factors that affect the extraction, such as loading buffer, eluting buffer, and elution volume, were investigated in detail and optimized by using standard samples. Results reveal that the developed SPE approach had higher recoveries for PLs than that based on pure TiO2 particles. The proposed SPE method was used for extraction of PLs from serum and showed great potential for identifying more kinds of endogenous PL metabolites by ultra performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-QTOF MS). The proposed SPE method with the composite sorbent was used to screen PLs from a biological matrix with high selectivity and efficiency. This approach is a promising method for selective extraction of PLs in lipidomics or phospholipidomics. PMID:24725887

  4. Simultaneous determination of triclosan, triclocarban, and transformation products of triclocarban in aqueous samples using solid-phase micro-extraction-HPLC-MS/MS.

    Science.gov (United States)

    Shen, Jermiah Y; Chang, Matt S; Yang, Sheng-Hsiung; Wu, Gaston J

    2012-10-01

    The presence of triclosan and triclocarban, two endocrine-disrupting chemicals and antimicrobial agents, and transformation products of triclocarban, 1,3-di(phenyl)urea, 1,3-bis(4-chlorophenyl)urea and 1,3-bis(3,4-dichlorophenyl)urea, in tap water, treated household drinking water, bottled water, and river water samples were investigated using solid-phase micro-extraction coupled with-HPLC-MS/MS, a rapid, green, and sensitive method. Factors influencing the quantity of the analytes extracted onto the solid-phase micro-extraction fiber, such as addition of salt, sample pH, extraction time, desorption time, and sample volume, were optimized using solid-phase micro-extraction-HPLC-MS/MS. The results showed that the method gave satisfactory sensitivities and precisions for analyzing sub-part-per-trillion levels of triclosan, triclocarban, and transformation products of triclocarban in samples collected locally. The recoveries of analytes ranged from 97 to 107% for deionized water samples, and 99 to 110% for river water samples, and limits of detection were in the range of 0.32-3.44 and 0.38-4.67 ng/L for deionized water and river water samples, respectively. On average, the daily consumption of triclosan and triclocarban by an adult by consuming 2 liters of different types of drinking water were estimated to be in the range of 6.13-425 ng/day as a result of the concentrations of triclosan and triclocarban measured in this study. PMID:22907835

  5. 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

    OpenAIRE

    Antonio Luiz Pires Valente; Fabio Augusto; Larisse Montero; Eduardo Carasek da Rocha; Janusz Pawliszyn

    1998-01-01

    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 l...

  6. An Experimental Design Approach for the Analysis of Liquid Phase Products in Water for Hydrogenolysis of Glycerol using Immersed Solid-Phase Micro extraction

    International Nuclear Information System (INIS)

    In this study, a response surface methodology (RSM) was applied to optimize the immersed-solid-phase micro extraction (immersed-SPME) conditions for the first time using a polyacrylate (PA) coated fiber. This was to determine liquid phase compounds in water for hydrogenolysis reaction of glycerol. There are a three-factor response surface experimental design was used to evaluate the interactive effects of extraction temperature (30-70 degree Celsius), extraction time (10-30 minutes) and desorption time (2-18 minutes) on the analysis of liquid phase compounds in water for hydrogenolysis of glycerol using immersed-solid-phase micro extraction (immersed-SPME). The extraction conditions using immersed-SPME were optimized in order to achieve high enrichment of the analytes from aqueous samples. The isolated compounds from the SPME fiber were desorbed and separated on a capillary polar column of a gas chromatography-flame ionization detector (GC-FID). The extraction time and desorption time were found significant in increasing the amount of glycerol in aqueous hydrogenolysis of glycerol. Nevertheless, the effect of extraction temperature was not significant. In terms of interactions between the effects, the relation between extraction temperature and extraction time was the most significant. The optimised immersed-SPME conditions were at extraction temperature of 27 degree Celsius, extraction time of 30 minutes and 15 minutes of desorption time. Thus, the application of SPMorption time. Thus, the application of SPME was found to be a rapid and effective technique in the determination of glycerol and propylene glycol compounds in aqueous hydrogenolysis glycerol. (author)

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

    Science.gov (United States)

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

    2015-05-01

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

  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. A new solid phase micro extraction for simultaneous head space extraction of ultra traces of polar and non-polar compounds.

    Science.gov (United States)

    Alizadeh, Reza; Najafi, Nahid Mashkouri; Kharrazi, Sharmin

    2011-03-01

    The results of the innovative study on a new stationary phase with high efficiency based on ZnO nano and micro rod coating on fused silica are reported in this paper. ZnO nanorods with a diameter in the range of 70-300 nm and the length of about 500 nm, have been grown on fused silica fibers using a hydrothermal process. The extraction properties of the fiber were investigated using headspace solid-phase microextraction (HS-SPME) mode coupled with gas chromatography-mass spectrometry detection (GC-MS) for 1,4-dichloro-nitrobenzene, biphenyl and acenaphthene. The calibration curves were linear up to 10(2)-10(7) ng L(-1) (R(2)>0.995) with detection limits of 10(-3) ng L(-1) for biphenyl and acenaphthene and 10 ng L(-1) for 1,4-dichloro-nitrobenzene. The RSD for single fiber and fiber-to-fiber were less than 7.0 and 11.5%, respectively. The high stability of the ZnO coating is proved at relatively high temperatures (up to 300°C) with a high extraction capacity and long lifespan (more than 100 times). Promising recoveries (91-102%) were obtained in environmental water samples analysis by applying the proposed technique. PMID:21338766

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

    Science.gov (United States)

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

    2015-03-20

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

  11. 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

  12. 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

  13. 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.

  14. Magnetized silane-coupling agent KH-570 based solid-phase extraction followed by gas chromatography-flame ionization detection to determine venlafaxine in human hair and aqueous environmental samples.

    Science.gov (United States)

    Ebrahimi, Mahmoud; Ebrahimitalab, Abdolhossein; Es'haghi, Zarrin; Mohammadinejad, Arash

    2015-02-01

    In the present study, a novel adsorbent, Fe3O4 magnetic nanoparticles (MNPs) functionalized by silane-coupling agent KH-570, was successfully synthesized. The prepared MNPs were characterized by Fourier-transform infrared spectroscopy and transmission electron microscopy. It was applied as functionalized magnetic nano-adsorbent for magnetic solid-phase extraction of trace levels of venlafaxine using gas chromatography with flame ionization detector. This method was developed and optimized for use in analysis of venlafaxine in human hair and aqueous environmental samples. The main factors influencing the extraction efficiency including pH of sample, amount of the MNPs, adsorption time, volume of sample, and desorption conditions such as volume of solvent and desorption time were studied and optimized. Under the optimized experimental conditions, good linearity was observed in the range of 1-1,000 µg L(-1) for aqueous environmental samples with correlation coefficients (R (2)) 0.996. The limits of detection and quantification were 0.1 and 0.5 ?g L(-1), respectively. Good reproducibility with the relative standard deviations (n = 5) 3.21 % was obtained. The developed method was successfully applied to the extraction of venlafaxine from spiked human hair, river water, and surface water samples and the relative recoveries of 89.36, 93.43, and 94.99 % were obtained, respectively. The results indicated that Fe3O4/KH-570 MNPs have a satisfying extraction efficiency and can be served as a sensitive, inexpensive, and reliable method for analysis of antidepressant drugs such as venlafaxine in biological and aqueous environmental samples. PMID:25367213

  15. 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

  16. Flow injection on-line solid phase extraction coupled with inductively coupled plasma mass spectrometry for determination of (ultra)trace rare earth elements in environmental materials using maleic acid grafted polytetrafluoroethylene fibers as sorbent.

    Science.gov (United States)

    Wang, Zhao-Hui; Yan, Xiu-Ping; Wang, Zhi-Peng; Zhang, Zheng-Pu; Liu, Li-Wen

    2006-09-01

    A new sorbent, maleic acid grafted polytetrafluoroethylene fiber (MA-PTFE), was prepared and evaluated for on-line solid-phase extraction coupled with inductively coupled plasma mass spectrometry (ICP-MS) for fast, selective, and sensitive determination of (ultra)trace rare earth elements (REEs) in environmental samples. The REEs in aqueous samples at pH = 3.0 were selectively extracted onto a microcolumn packed with the MA-PTFE fiber, and the adsorbed REEs were subsequently eluted on-line with 0.9 mol l(-1) HNO3 for ICP-MS determination. The new sorbent extraction system allows effective preconcentration and separation of the REEs from the major matrix constituents of alkali and alkali earth elements, particularly their separation from barium that produces considerable isobaric interferences of 134Ba16O1H+, 135Ba16O+, 136Ba16O1H+, and 137Ba16O+ on 151Eu+ and 153Eu+. With the use of a sample loading flow rate of 7.4 ml min(-1) for 120 s preconcentration, enhancement factors of 69-97 and detection limits (3s) of 1-20 pg l(-1) were achieved at a sample throughput of 22 samples h(-1). The precision (RSD) for 16 replicate determinations of 50 ng l(-1) of REEs was 0.5-1.1%. The developed method was successfully applied to the determination of (ultra)trace REEs in sediment, soil, and seawater samples. PMID:16814561

  17. Determination of polycyclic aromatic hydrocarbons in Persian Gulf and Caspian Sea: gold nanoparticles fiber for a head space solid phase micro extraction.

    Science.gov (United States)

    Karimi, Mohammad; Aboufazeli, Forouzan; Zhad, Hamid Reza Lotfi Zadeh; Sadeghi, Omid; Najafi, Ezzatollah

    2013-03-01

    A gold nanoparticles modified fused silica fiber was developed and used for the head space solid phase micro-extraction (HS-SPME) of polycyclic aromatic hydrocarbons (PAHs), including naphthalene, anthracene, acenaphthylene, phenanthrene, fluoranthene and pyrene. The effects of different parameters influencing the extraction efficiency including extraction temperature, extraction time, ionic strength, stirring rate and sample volume were examined and optimized. Linear ranges of 1-300 ?g L(-1) for naphthalene, 0.5-250 ?g L(-1) for anthracene, acenaphthylene and phenanthrene and 0.05-200 ?g L(-1) for fluoranthene and pyrene were obtained. Detection limits were in the range of 10-200 ?g L(-1). Single fiber repeatability and fiber to fiber reproducibility were less than 2.5 %-6.0 % and 8.5 %-13.6 %, respectively. Seawater samples were analyzed as real samples and good recoveries (91.9 %-105.3 %) were obtained for target analytes. PMID:23183967

  18. Multiresidue determination of pesticides in drinking and related waters by solid-phase extraction and liquid chromatography with ultraviolet detection: interlaboratory study.

    Science.gov (United States)

    Van Hoof, François; Van Wiele, Peter; Acobas, Franvoise; Guinamant, Jean-Luc; Bruchet, Auguste; Schmitz, Isabelle; Bobeldijk, Ivana; Sacher, Frank; Ventura, Francesc; Boleda, Rosa

    2002-01-01

    As part of a project funded by the European Commission (EC) for the development and evaluation of multiresidue methods for analysis of drinking and related waters, 17 European laboratories evaluated a method using styrene-divinylbenzene copolymer solid-phase extraction followed by liquid chromatography with diode array detection. The main aim of the study was to evaluate whether the method meets the requirements of EC Drinking Water Directive 98/83 in terms of accuracy, precision, and detection limit for 21 pesticides according to the following requirements: limit of detection, metamitron. However, several compounds (linuron, terbutryn, propazine, metobromuron, and isoproturon) showed recoveries slightly below 75%. PMID:11990022

  19. Determination of etoricoxib in human plasma using automated on-line solid-phase extraction coupled with LC-APCI/MS/MS

    OpenAIRE

    Sérgio Luiz Dalmora; Liberato Brum Junior; Ricardo Machado Ferretto; Paulo Renato de Oliveira; Thiago Barth; Maximiliano da Silva Sangoi

    2008-01-01

    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 (...

  20. Comparative study of the sol-gel based solid phase microextraction fibers in extraction of naphthalene, fluorene, anthracene and phenanthrene from saffron samples extractants

    International Nuclear Information System (INIS)

    We are introducing a method for the determination of some polycyclic aromatic hydrocarbons in aqueous saffron sample by direct immersion solid phase microextraction (SPME) and gas chromatography. A sol-gel technique is used for the preparation of the SPME fibers. Three kinds of sol-gel coatings on the fibers were tested and compared. They are composed of poly(dimethyl siloxane) (PDMS), poly(ethylene glycol) (PEG), and a poly(ethylene glycol) modified with multi-walled carbon nanotubes (PEG/CNTs). The effects of fiber coating, desorption time, desorption temperature, extraction time, stirring speed and salting effect were optimized. Under the optimal conditions, the detection limits (at S/N = 3) are 7-50, 5-50, and 1-10 pg mL-1, respectively, for SPME fibers made from PDMS, PEG and PEG/CNTs. The relative standard deviations for one type of fiber are from 2.1% to 9.6% for all fibers (at n = 5), and in the range from 1.9% to 9.8% from batch to batch (for n = 3). (author)

  1. 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

  2. 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.

  3. 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

  4. 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 satisface 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Lei; Han Fang; Hu Yanyun [Anhui Entry-Exit Inspection and Quarantine Bureau, 329 Tunxi Road, Hefei, Anhui 230029 (China); Anhui Province Key Laboratory of Analysis and Detection for Food Safety, 329 Tunxi Road, Hefei, Anhui 230029 (China); Zheng Ping, E-mail: ahciq_hx@163.com [Anhui Entry-Exit Inspection and Quarantine Bureau, 329 Tunxi Road, Hefei, Anhui 230029 (China) and Anhui Province Key Laboratory of Analysis and Detection for Food Safety, 329 Tunxi Road, Hefei, Anhui 230029 (China); Sheng Xuan; Sun Hao [Anhui Entry-Exit Inspection and Quarantine Bureau, 329 Tunxi Road, Hefei, Anhui 230029 (China); Song Wei; Lv Yaning [Anhui Province Key Laboratory of Analysis and Detection for Food Safety, 329 Tunxi Road, Hefei, Anhui 230029 (China)

    2012-06-04

    Highlights: Black-Right-Pointing-Pointer Hyperchem was used to simulate chloroacetamide herbicides and their metabolites. Black-Right-Pointing-Pointer Clustering analysis was conducted to analyze the structural data. Black-Right-Pointing-Pointer Metolachlor deschloro was selected as the dummy template to synthesize DMIPs. Black-Right-Pointing-Pointer The elution order of herbicides on DMIPs was predicted using clustering analysis. Black-Right-Pointing-Pointer 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.

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

    Science.gov (United States)

    Zhang, Lei; Han, Fang; Hu, Yanyun; Zheng, Ping; Sheng, Xuan; Sun, Hao; Song, Wei; Lv, Yaning

    2012-06-01

    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. PMID:22595431

  7. [Determination of seven pesticide residues in bamboo shoots by high performance liquid chromatography-tandem mass spectrometry coupled with solid-phase extraction].

    Science.gov (United States)

    Ding, Ming; Zhong, Donglian; Tang, Fubin; Fang, Wei

    2013-02-01

    A simple and efficient method based on solid-phase extraction (SPE) and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was developed for the determination of butylene fipronil, chlorpyrifos, chlorantraniliprole, fipronil, imidacloprid, indoxacarb and phoxim residues in bamboo shoots. The sample was extracted with acetonitrile and purified by a primary secondary amine (PSA) solid-phase extraction cartridge. The detection of targets was performed by HPLC-MS/MS with multiple reaction monitoring (MRM) mode. All the seven pesticides were completely separated in 15 min with an excellent linear relationship. The limits of detection and the limits of quantification for the seven pesticides were 0.02-0.5 microg/kg and 0.08-1.5 microg/kg, respectively. The recoveries of the seven pesticides spiked in a bamboo shoot sample at the levels of 4, 8, 32 microg/kg were in the range from 76.0% to 102.6% (the RSD < or = 11.0%, n = 3). The method was successfully applied to the real bamboo shoot samples. The method has high accuracy and sensitivity, and is simple and quick. It can meet the requirement of the simultaneous determination of the seven pesticides in bamboo shoots. PMID:23697174

  8. 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 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

  9. Determination of Sudan dyes in chili pepper powder by online solid-phase extraction with a butyl methacrylate monolithic column coupled to liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Liu, Yao; Wang, Man-Man; Ai, Lian-Feng; Zhang, Chang-Kun; Li, Xin; Wang, Xue-Sheng

    2014-07-01

    A poly(butyl methacrylate-co-ethylene dimethacrylate) monolithic column was fabricated and used as a novel sorbent for online solid-phase extraction coupled to liquid chromatography with tandem mass spectrometry for the simultaneous determination of Sudan I-IV in chili pepper powder. The prepared columns were characterized by scanning electron microscopy, nitrogen adsorption-desorption, and pressure drop measurements. Online solid-phase extraction was performed on the synthesized monolithic column using 10 mM ammonium acetate solution as the loading solution with the aid of an online cleanup chromatography system. The desorption of Sudan I-IV was achieved with acetonitrile as the eluting solution at the flow rate of 0.5 mL/min. The extracted analytes were subsequently eluted into a C18 analytical column for chromatographic separation using a mixture of 10% acetonitrile/90% formic acid (0.5%) solution as the mobile phase. Under the optimized conditions, the developed method had linear range of 1.0-50 ?g/kg, a detection limit of 0.3 ?g/kg, and a quantification limit of 1.0 ?g/kg for each analyte. The intraday and interday recoveries of Sudan I-IV in chili pepper powder samples ranged from 94.8 to 100.9% and 94.9 to 99.4%, respectively. The intraday and interday precision were between 3.37-7.01% and 5.01-7.68%, respectively. PMID:24723310

  10. Graphene oxide-based dispersive micro-solid phase extraction for separation and preconcentration of nicotine from biological and environmental water samples followed by gas chromatography-flame ionization detection.

    Science.gov (United States)

    Mahpishanian, Shokouh; Sereshti, Hassan

    2014-12-01

    Graphene oxide (GO) has showed great potential to use as an adsorbent in sample preparation procedures. In this research, GO was used as an effective adsorbent in a simple GO-based dispersive micro-solid phase extraction (GO-D-µ-SPE) method for isolation and preconcentration of nicotine prior to gas chromatography-flame ionization detection (GC-FID). The prepared GO was characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM), thermogravimetric analysis/differential thermal analysis (TGA/DTA), and ultraviolet-visible (UV-vis) absorption spectroscopy techniques. Various experimental parameters affecting the extraction recovery, including the amount of GO, extraction time, pH of the sample solution, salt concentration, and desorption conditions were investigated and optimized. Under the optimized conditions, a linear response was obtained in the concentration range of 5-2000 ng mL(-1) with a determination coefficient of 0.9987. The limit of detection (LOD) of the method at a signal to noise ratio of 3 was 1.5 ng mL(-1). The linearity was in the concentration range of 5-2000 ng mL(-1) with a determination coefficient of 0.9987. Intraday and inter-day precisions were obtained equal to 2.7% and 5.2%, respectively. The method was successfully applied to the nicotine analysis in biological and water samples with the recoveries in the range of 88.7-109.7%. PMID:25159381

  11. 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.

  12. Determination of Low Concentrations of Acetochlor in Water by Automated Solid-Phase Extraction and Gas Chromatography with Mass-Selective Detection

    Science.gov (United States)

    Lindley, C.E.; Stewart, J.T.; Sandstrom, M.W.

    1996-01-01

    A sensitive and reliable gas chromatographic/mass spectrometric (GC/MS) method for determining acetochlor in environmental water samples was developed. The method involves automated extraction of the herbicide from a filtered 1 L water sample through a C18 solid-phase extraction column, elution from the column with hexane-isopropyl alcohol (3 + 1), and concentration of the extract with nitrogen gas. The herbicide is quantitated by capillary/column GC/MS with selected-ion monitoring of 3 characteristic ions. The single-operator method detection limit for reagent water samples is 0.0015 ??g/L. Mean recoveries ranged from about 92 to 115% for 3 water matrixes fortified at 0.05 and 0.5 ??g/L. Average single-operator precision, over the course of 1 week, was better than 5%.

  13. 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.

  14. 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.

  15. Extraction en phase solide de 22 médicaments d'intérêt en toxicologie médico-légale Solid phase extraction of 22 drugs of interest in the forensic toxicology field

    Directory of Open Access Journals (Sweden)

    Mancebo Mélinda

    2008-06-01

    Full Text Available De nombreuses colonnes d'extraction en phase solide dédiées à l'extraction des toxiques et leurs protocoles spécifiques sont proposées à l'analyste. Nous avons optimisé l'un de ces protocoles pour l'extraction à partir de sang total – en une seule étape – de principes actifs de médicaments acides, neutres et basiques. Chaque niveau du protocole a été conçu de manière à obtenir les meilleurs rendements d'extraction. L'analyse des extraits (identification et quantification a été réalisée à l'aide d'un système de High Performance Liquid Chromatography system with Diode Array Detector (HPLC-DAD. La colonne SPE Evolute ABN$^{ext{extregistered}}$ (Acid Base Neutral fournie par Argonaut est celle qui extrait le mieux les différents composés analysés parmi toutes les cartouches testées. La colonne Oasis HLB$^{ext{extregistered}}$ (Hydrophilic Lipophilic Balance proposée par Waters permet également l'extraction de la totalité des molécules mais avec des rendements inférieurs. Quant aux autres colonnes étudiées (distribuées par Varian et Phenomenex, elles ont présenté des résultats insuffisants dans le cadre de ce projet. Les limites de détection et de quantification obtenues avec ce protocole optimisé ont été comparées aux concentrations thérapeutiques et toxiques habituellement retrouvées. La mise au point de cette nouvelle procédure a permis d'optimiser une méthode de dépistage large (criblage de médicaments fréquemment rencontrés dans les matrices biologiques en toxicologie clinique et médico-légale. Many solid phase extraction columns which are dedicated to the extraction of various drugs associated with their specific protocols are proposed to the analyst. We have optimised a one stage procedure for the extraction from whole blood of acidic, neutral and basic drugs. Each step of the protocol has been optimised so as to obtain the best extraction recovery. The analysis of the extracts (identification and quantification has been realised with the help of High Performance Liquid Chromatography system coupled with a Diode Array Detector (HPLC-DAD. The SPE Evolute ABN$^{ext{extregistered}}$ column (Acid Base Neutral by Argonaut is the column which does extract the more and the best the different analysed components among all the columns which have been tested. Oasis HLB$^{ext{extregistered}}$ column (Hydrophilic Lipophilic Balance by Waters also allows the extraction of the whole list of active principles studied but with lower recoveries. The other columns studied (sold by Varian and Phenomenex presented insufficient results for this project. In the last step of the work we checked if the results did fit to the forensic toxicology purpose; detection and quantification limits have been compared to therapeutic and toxic concentrations usually found in forensic toxicology. Implementing this new procedure allowed us to create a method of comprehensive screening of drugs frequently implicated in forensic toxicology.

  16. 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: 1.7ngL(-1) (metoprolol) - 1321ngL(-1) (tramadol) in influent,

  17. 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

  18. New sorbent in the dispersive solid phase extraction step of quick, easy, cheap, effective, rugged, and safe for the extraction of organic contaminants in drinking water treatment sludge.

    Science.gov (United States)

    Cerqueira, Maristela B R; Caldas, Sergiane S; Primel, Ednei G

    2014-04-01

    Recent studies have shown a decrease in the concentration of pesticides, pharmaceuticals and personal care products (PCPs) in water after treatment. A possible explanation for this phenomenon is that these compounds may adhere to the sludge; however, investigation of these compounds in drinking water treatment sludge has been scarce. The sludge generated by drinking water treatment plants during flocculation and decantation steps should get some special attention not only because it has been classified as non-inert waste but also because it is a very complex matrix, consisting essentially of inorganic (sand, argil and silt) and organic (humic substances) compounds. In the first step of this study, three QuEChERS methods were used, and then compared, for the extraction of pesticides (atrazine, simazine, clomazone and tebuconazole), pharmaceuticals (amitriptyline, caffeine, diclofenac and ibuprofen) and PCPs (methylparaben, propylparaben, triclocarban and bisphenol A) from drinking water treatment sludge. Afterwards, the study of different sorbents in the dispersive solid phase extraction (d-SPE) step was evaluated. Finally, a new QuEChERS method employing chitin, obtained from shrimp shell waste, was performed in the d-SPE step. After having been optimized, the method showed limits of quantification (LOQ) between 1 and 50 ?g kg(-1) and the analytical curves showed r values higher than 0.98, when liquid chromatography tandem mass spectrometry was employed. Recoveries ranged between 50 and 120% with RSD?15%. The matrix effect was evaluated and compensated with matrix-matched calibration. The method was applied to drinking water treatment sludge samples and methylparaben and tebuconazole were found in concentration

  19. Uranium extraction from sea water with composite adsorbents, (3)

    International Nuclear Information System (INIS)

    Measurements were made of the extent of magnetization shown by composite hydrous titanium (IV)-iron (II) oxide adsorbents for use in uranium extraction from sea water. The possibility of removing the adsorbent by means of high-gradient magnetic separation was demonstrated by calculations based on a force balance model. Removal experiments were also carried out, which demonstrated that the composite hydrous oxide can be trapped effectively: A composite hydrous oxide with 1:1 Ti-to-Fe mole ratio, of 400 -- 625 mesh particle size, proved to be removed to 99.9% by a magnetic field of 2.5 kOe, with the slurry flowing at 20 cm/s through a filter matrix 50 cm long packed to 90% void with 100 ?m diameter nickel wire stuffing. Together with the evaluations made of the electric power consumed by the high-gradient magnetic separators, the experimental results indicated the possibility of economically extracting uranium from sea water using these separators in combination with magnetic adsorbents. (author)

  20. Analysis of trace levels of sulfonamide and tetracycline antimicrobials in groundwater and surface water using solid-phase extraction and liquid chromatography/mass spectrometry

    Science.gov (United States)

    Lindsey, M.E.; Meyer, M.; Thurman, E.M.

    2001-01-01

    A method has been developed for the trace analysis of two classes of antimicrobials consisting of six sulfonamides (SAs) and five tetracyclines (TCs), which commonly are used for veterinary purposes and agricultural feed additives and are suspected to leach into ground and surface water. The method used solid-phase extraction and liquid chromatography/mass spectrometry (LC/MS) with positive ion electrospray. The unique combination of a metal chelation agent (Na2EDTA) with a macroporous copolymer resulted in quantitative recoveries by solid-phase extraction (mean recovery, 98 ?? 12%) at submicrogram-per-liter concentrations. An ammonium formate/formic acid buffer with a methanol/water gradient was used to separate the antimicrobials and to optimize the signal intensity. Mass spectral fragmentation and ionization characteristics were determined for each class of compounds for unequivocal identification. For all SAs, a characteristic m/z 156 ion representing the sulfanilyl fragment was identified. TCs exhibited neutral losses of 17 amu resulting from the loss of ammonia and 35 amu from the subsequent loss of water. Unusual matrix effects were seen only for TCs in this first survey of groundwater and surface water samples from sites around the United States, requiring that TCs be quantitated using the method of standard additions.

  1. 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.

  2. 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 reange 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.

  3. High-performance liquid chromatographic determination of famotidine in human plasma using solid-phase column extraction

    Directory of Open Access Journals (Sweden)

    DRAGICA ZENDELOVSKA

    2003-11-01

    Full Text Available A rapid, specific and sensitive high-performance liquid chromatographic method for the determination of famotidine in human plasma has been developed. Famotidine and the internal standard were chromatographically separated from plasma components using a Lichrocart Lichrospher 60 RP selec B cartridge for solid-phase separation with a mobile phase composed of 0.1 % (v/v triethylamine in water (pH 3 and acetonitrile (92:8, v/v. UV detection was set at 270 nm. The calibration curve was linear in the concentration range of 10.0 ? 350.0 ng mL-1. The method was implemented to monitor the famotidine levels in patient samples.

  4. Estrógenos em água: otimização da extração em fase sólida utilizando ferramentas quimiométricas / Estrogens in water: optimization of solid phase extraction by chemometric tools

    Scientific Electronic Library Online (English)

    G., Girotto; K. L., Nogueira; J. A., Moura; J. B., Souza; L. L., Giacometti; M. R.R., Marchi; J. O., Tognolli.

    Full Text Available Muitos métodos analíticos estão sendo desenvolvidos visando à determinação de contaminantes orgânicos, especialmente alteradores endócrinos. Tais métodos baseiam-se geralmente na extração em fase sólida (SPE) seguida por determinação cromatográfica (CG ou HPLC). No presente trabalho utilizou-se ferr [...] amentas quimiométricas no processo de SPE para avaliar os principais fatores que influenciam tal processo e as interações entre os mesmos. Foram analisadas matrizes de água subterrânea fortificada com hormônios (17 b estradiol, estrona e 17 b etinilestradiol) e a determinação analítica foi feita por HPLC/Fluorescência. Um planejamento fatorial completo foi utilizado. Os fatores escolhidos incluíram: condicionamento da fase sólida, concentração dos analitos, volume da amostra e solvente de eluição. As melhores condições obtidas foram: 500 mL da amostra, condicionamento da fase sólida (C18) com acetona (4mL), metanol (6 mL) e água pH 3(10 mL), e eluição dos analitos com 4 mL de acetona. Abstract in english Several analytical methods have been proposed for organic pollutants determination in water, specially endocrine disrupters. These methods are frequently based in solid phase extraction (SPE) followed by chromatographic determination (GC or HPLC). In this work it was used chemometric tools on experi [...] mental design and experimental data treatment to evaluate the principal factors in SPE process and their interactions. It was used water matrices fortified with hormones (17 b estradiol, estrone and 17 b ethinylestradiol) and HPLC/Fluorescence did analytical determination. It was used a factorial complete design. The choosed factors included: solid phase type, analytes concentration, sample volumen, eluent composition, analytes concentration and solvents to solid phase conditioning. The best condition obtained in this initial procedure included: 500 mL sample, conditioning SPE cartridge with acetone (4mL), methanol (6 mL) and water pH 3(10 mL), and analytes elution with acetone.

  5. 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, anilintivity. 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)

  6. 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)

  7. Rapid analysis of trace organic compounds in water by automated online solid-phase extraction coupled to liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Anumol, Tarun; Snyder, Shane A

    2015-01-01

    A fully automated online solid-phase extraction (SPE) with directly coupled liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for analysis of 34 trace organic compounds in diverse water matrices has been developed. The current method offers several advantages over traditional offline SPE methods including low sample volume (1.7 mL), decreased solvent use, higher throughput, and increased reproducibility. The method uses simultaneous positive and negative ESI for analysis of all compounds in one injection, which reduces cycle time (extraction+analysis) to retention time locking and use of two transitions for most compounds increased the specificity. The applicability of the method was tested on samples across treatment points from two wastewater plants, a septic tank, surface water and groundwater. PMID:25476282

  8. Simultaneous Detection of Sulfamethoxazole, Diclofenac, Carbamazepine, and Bezafibrate by Solid Phase Extraction and High Performance Liquid Chromatography with Diode Array Detection

    Science.gov (United States)

    Zhou, Z.; Jiang, J.-Q.

    2014-05-01

    A method of solid phase extraction (SPE) coupled with high performance liquid chromatography and diode array detection (HPLC-DAD) was studied for the simultaneous determination of sulfamethoxazole (SMX), diclofenac (DCF), carbamazepine (CBZ), and bezafi brate (BZF) in test solutions. The target compounds were extracted by SPE from samples, and the resulting elutes were analyzed using a HPLC-DAD system at wavelengths of 270, 280, 290, and 230 nm for SMX, DCF, CBZ, and BZF, respectively. This method shows good recoveries for SMX, DCF, CBZ, and BZF with mean recoveries of 89.7 ± 9.3%, 86.1 ± 7.6%, 95.0 ± 6.5%, and 94.0 ± 5.4%, respectively.

  9. 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.

  10. 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

  11. 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.)

  12. 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)

  13. Aroma quality assessment of Korean fermented red pepper paste (gochujang) by aroma extract dilution analysis and headspace solid-phase microextraction-gas chromatography-olfactometry.

    Science.gov (United States)

    Kang, Kyung-Mo; Baek, Hyung-Hee

    2014-02-15

    The objective of this study was to assess aroma quality of gochujang using purge and trap, simultaneous steam distillation and solvent extraction (SDE), and headspace solid-phase microextraction (HS-SPME), followed by gas chromatography-olfactometry (GC-O). Nineteen and 28 aroma-active compounds were detected by aroma extract dilution analysis of purge and trap and SDE, respectively. Diallyl disulfide and 3-isobutyl-2-methoxypyrazine played a significant role in the aroma quality of gochujang. Twelve aroma-active compounds were detected by HS-SPME-GC-O based on sample dilution analysis. Methional, diallyl disulfide, and 3-isobutyl-2-methoxypyrazine were the most intense aroma-active compounds. 3-Isobutyl-2-methoxypyrazine was identified for the first time in gochujang. PMID:24128505

  14. Forensic analysis of a single particle of partially burnt gunpowder by solid phase micro-extraction-gas chromatography-nitrogen phosphorus detector.

    Science.gov (United States)

    Burleson, Garrett Lee; Gonzalez, Brittney; Simons, Kelsie; Yu, Jorn C C

    2009-05-29

    Solid phase micro-extraction (SPME) was adopted to extract organic gun shot residues (OGSRs) from a single particle of partially burnt gunpowder. The partially burnt particle samples were collected from gun shot residue (GSR) deposited near the target areas. OGSRs, such as diphenylamine (DPA), methyl centralite (MC), ethyl centralite (EC), from only one single particle of partially burnt gunpowder were successfully extracted by SPME and analyzed by a gas chromatography coupled to a nitrogen phosphorus detector (GC-NPD). The results confirmed that the new extraction procedure is capable of extracting trace amount of MC and EC as signature molecules for the identification of GSR. The method represents a solvent-free extraction as a complementary analytical procedure for the forensic analysis of GSR-related evidences. The new extraction scheme with the capability of analyzing single particle of partially burnt gunpowder can also be applied to the identification of explosive residues, such as in post-blast investigations of improvised explosive devices. PMID:19375082

  15. 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)

  16. Liquid Metering Centrifuge Sticks (LMCS): A Centrifugal Approach to Metering Known Sample Volumes for Colorimetric Solid Phase Extraction (C-SPE)

    Science.gov (United States)

    Gazda, Daniel B.; Schultz, John R.; Clarke, Mark S.

    2007-01-01

    Phase separation is one of the most significant obstacles encountered during the development of analytical methods for water quality monitoring in spacecraft environments. Removing air bubbles from water samples prior to analysis is a routine task on earth; however, in the absence of gravity, this routine task becomes extremely difficult. This paper details the development and initial ground testing of liquid metering centrifuge sticks (LMCS), devices designed to collect and meter a known volume of bubble-free water in microgravity. The LMCS uses centrifugal force to eliminate entrapped air and reproducibly meter liquid sample volumes for analysis with Colorimetric Solid Phase Extraction (C-SPE). C-SPE is a sorption-spectrophotometric platform that is being developed as a potential spacecraft water quality monitoring system. C-SPE utilizes solid phase extraction membranes impregnated with analyte-specific colorimetric reagents to concentrate and complex target analytes in spacecraft water samples. The mass of analyte extracted from the water sample is determined using diffuse reflectance (DR) data collected from the membrane surface and an analyte-specific calibration curve. The analyte concentration can then be calculated from the mass of extracted analyte and the volume of the sample analyzed. Previous flight experiments conducted in microgravity conditions aboard the NASA KC-135 aircraft demonstrated that the inability to collect and meter a known volume of water using a syringe was a limiting factor in the accuracy of C-SPE measurements. Herein, results obtained from ground based C-SPE experiments using ionic silver as a test analyte and either the LMCS or syringes for sample metering are compared to evaluate the performance of the LMCS. These results indicate very good agreement between the two sample metering methods and clearly illustrate the potential of utilizing centrifugal forces to achieve phase separation and metering of water samples in microgravity.

  17. Solid phase extraction in tandem with GC/MS for the determination of semi-volatile organic substances extracted from pharmaceutical packaging/delivery systems via aqueous solvent systems.

    Science.gov (United States)

    Zdravkovic, Steven A

    2015-08-10

    An extractable survey is one of several studies performed on a pharmaceutical storage/delivery system as part of the process of demonstrating that the system is suitable for its intended use. In this paper, a solid phase extraction method for the preparation of aqueous extracts generated during an extractable survey is presented. The method offers a convenient means to isolate semi-volatile organic extractable compounds from aqueous extraction solvents for analysis by gas chromatography/mass spectrometry. Following the solid phase extraction procedure, derivatization is performed to convert problematic functionalities (such as amines and acids) into appropriate chromatographically friendly derivatives. Demonstration of method performance is achieved in three ways using a set of 31 commonly observed extractable substances as model compounds. First, a breakthrough experiment was performed with a 2 solvent system consisting of water and 10/90 isopropanol/water over a range of 6mL to 100mL. Results from this experiment show only caprolactam possessed a significant level of breakthrough in either solvent over the range of volumes evaluated. Second, a formal accuracy/precision study was conducted using a three solvent system consisting of water, 10/90 isopropanol/water and 1% polysorbate 80. This experiment demonstrates the quantitative ability of the method at levels ranging from 20ng/mL to 50?g/mL. Recovery values of 70% to 130% of the theoretical concentration, with relative standard deviation values of less than 15% for replicate preparations, are obtained for a majority of the compounds evaluated. Finally, a case study involving the extraction of an intravenous drug delivery bag with multiple aqueous solvent systems further demonstrates the viability of solid phase extraction for use in an extractables survey. PMID:25978495

  18. 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.

  19. Silica chemically bonded N-propyl kriptofix 21 and 22 with immobilized palladium nanoparticles for solid phase extraction and preconcentration of some metal ions

    International Nuclear Information System (INIS)

    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?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

  20. Trimethylsilyldiazomethane derivatization coupled with solid-phase extraction for the determination of alendronate in human plasma by LC-MS/MS.

    Science.gov (United States)

    Chen, Meixia; Liu, Ke; Zhong, Dafang; Chen, Xiaoyan

    2012-01-01

    Alendronate is an important representative of bisphosphonates, strongly polar compounds that lack chromophores. With rare exceptions, derivatization of the analytes is necessary for bioanalysis. In this study, a rapid liquid chromatography-tandem mass spectrometry method employing pre-column derivatization was developed and validated for the determination of alendronate concentrations in human plasma. The procedure was based on derivatization with trimethylsilyldiazomethane during solid-phase extraction on a weak anion-exchange solid-phase cartridge, which integrated sample purification and derivatization into one step. The alendronate derivative was eluted with methanol. Chromatographic separation was performed on a Capcell PAK-C18 column. The total run time was 6.5 min. The calibration curve was linear in the range 1.00-1,000 ng/mL using d6-alendronate as the internal standard. The lower limit of quantification was 1.00 ng/mL. The intra- and inter-assay precision (in RSD) calculated from quality control samples was less than 15%, and the accuracy was between 98.1% and 100.2%. The validated method was successfully applied to characterize the pharmacokinetic profiles of alendronate following the intravenous infusion of 5 or 10 mg alendronate sodium to healthy volunteers. PMID:22002562

  1. 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.

  2. The use of polyphenolic compounds from Black tea for the solid phase extraction and determination of trace iron in drinking water

    Energy Technology Data Exchange (ETDEWEB)

    Maleki, Ramin [Departmant of Chemistry, Faculty of Science, Urmia University, Urmia (Iran); Research Department of Chromatography, Iranian Academic Center for Education, Culture and Research (ACECR), Urmia Branch, Urmia (Iran); Nikkhahi, Yousef [Research Department of Chromatography, Iranian Academic Center for Education, Culture and Research (ACECR), Urmia Branch, Urmia (Iran); Farhadi, Khalil

    2009-11-15

    A simple and selective solid phase extraction procedure for the trace analysis of iron(III) in water samples has been developed. Sodium dodecyl sulfate coated alumina, modified with polyphenolic compounds (extracted from black tea) was used for the extraction and preconcentration of iron(III) from water samples before determination by flame atomic absorption spectrometry. Due to the complexation reaction between iron(III) and polyphenol compounds, iron(III) was quantitatively extracted on the proposed sorbent and then eluted by 2.0 mL of HCl (1.0 mol/L). The effects of extraction parameters, such as pH and volume of sample solution, amount of polyphenolic compounds, type of eluting agent and the effect of interfering ions on the extraction of iron(III), were investigated. It was found that the proposed method had a good linear range (15.0-100.0 {mu}g/L) and a low detection limit (10.0 {mu}g/L). The procedure was successfully applied for iron determination in drinking water samples. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  3. 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

  4. Preconcentration and separation of copper, nickel and zinc in aqueous samples by flame atomic absorption spectrometry after column solid-phase extraction onto MWCNTs impregnated with D2EHPA-TOPO mixture

    International Nuclear Information System (INIS)

    A solid phase extraction method has been developed for the determination of copper, nickel and zinc ions in natural water samples. This method is based on the adsorption of copper, nickel and zinc on multiwalled carbon nanotubes (MWCNTs) impregnated with di-(2-ethyl hexyl phosphoric acid) (D2EHPA) and tri-n-octyl phosphine oxide (TOPO). The influence of parameters such as pH of the aqueous solution, amount of adsorbent, flow rates of the sample and eluent, matrix effects and D2EHPA-TOPO concentration have been investigated. Desorption studies have been carried out with 2 mol L-1 HNO3. The copper, nickel and zinc concentrations were determined by flame atomic absorption spectrometry. The results indicated that the maximum adsorption of copper, nickel and zinc is at pH 5.0 with 500 mg of MWCNTs. The detection limits by three sigma were 50 ?g L-1 for copper, 40 ?g L-1 for nickel and 60 ?g L-1 zinc. The highest enrichment factors were found to be 25. The adsorption capacity of MWCNTs-D2EHPA-TOPO was found to be 4.90 mg g-1 for copper, 4.78 mg g-1 for nickel and 4.82 mg g-1 for zinc. The developed method was applied for the determination of copper, nickel and zinc in electroplating wastewater and real water sample with satisfactory results (R.S.D.'s <10%).

  5. Isotachophoretic determination of short-chain fatty acids in drinking water after solid-phase extraction with a carbonaceous sorbent.

    Science.gov (United States)

    Hutta, M; Simunicová, E; Kaniansky, D; Tkacova, J; Brtko, J

    1989-05-24

    A macroporous carbon sorbent, packed into disposable columns (Separcol-Carb), was investigated for the off-line preconcentration of short-chain fatty acids from drinking water in conjunction with their determination by capillary isotachophoresis (ITP). Of the acids investigated (C1-C9), butyric acid and higher homologues could be enriched into a high degree from samples of drinking water. Their detection limits from the ITP conductivity detector were in the low parts per 10(9) range when an amount equivalent to 8 ml of the sample was taken for analysis. The lowest homologues (C1-C3) were not adsorbed sufficiently to achieve their reasonable enrichment by the sorbent under the working conditions employed (acidification of the sample to pH 2.0). Acetone and diethyl ether were employed for the elution of the adsorbed analytes. The latter was more convenient in the analysis of practical samples as it co-eluted a considerably smaller number of the adsorbed anionic constituents. Octadecyl-bonded silica, evaluated in parallel, was found to be of only very limited utility for the same purpose. PMID:2738142

  6. Determination of trace amounts of plutonium in low-active liquid wastes from spent nuclear-fuel reprocessing plants by flow injection-based solid-phase extraction/electrochemical detection system

    International Nuclear Information System (INIS)

    A flow injection-based electrochemical detection system coupled to a solid-phase extraction column was developed for the determination of trace amounts of plutonium in low-active liquid wastes from spent nuclear-fuel reprocessing plants. The oxidation state of plutonium in a sample solution was adjusted to Pu(VI) by the addition of silver(II) oxide. A sample solution was made up in 3 mol L-1 HNO3 and loaded onto a column packed with UTEVAR with 3 mol L-1 HNO3 as the carrier. Plutonium(VI) was adsorbed onto the resin, and interfering elements were removed by rinsing the column with 3 mol L-1 HNO3. Subsequently, the adsorbed Pu(VI) was eluted with 0.01 mol L-1 HNO3, and then introduced directly into the flow-through electrolysis cell with boron-doped diamond electrode. The eluted Pu(VI) was detected by an electrochemical amperometric method at a working potential of 0.1 V (vs. Ag/AgCl). The current produced on reduction of Pu(VI) was continuously monitored and recorded. The plutonium concentration was calculated from the relationship between the peak area and concentration of plutonium. The relative standard deviation of ten analyses was 1.1% for a plutonium solution of 25 ?g L-1 containing 50 ng of Pu. The detection limit calculated from three-times the standard deviation was 0.82 ?g L-1 (1.6 ng of Pu). (author)or)

  7. 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)

  8. 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 tivity, 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)

  9. 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

  10. Separation of americium from plutonium-solvent extraction raffinate by extraction chromatography using TODGA adsorbent

    International Nuclear Information System (INIS)

    Separation of americium from plutonium-solvent extraction raffinate is planed to supply americium for the research on the high-temperature chemistry of TRU. An extraction chromatography technique was adopted to recover americium from the americium-containing raffinate. Efforts were made to separate neptunium from americium. As the result of chromatographic experiments using trivalent neodymium as a substitute for americium and the raffinate, it was concluded that new adsorbent TODGA is superior to CMPO adsorbent in regard to separation of americium from the raffinate. (authors)

  11. Determination of submicrogram-per-liter concentrations of caffeine in surface water and groundwater samples by solid-phase extraction and liquid chromatography

    Science.gov (United States)

    Burkhardt, M.R.; Soliven, P.P.; Werner, S.L.; Vaught, D.G.

    1999-01-01

    A method for determining submicrogram-per-liter concentrations of caffeine in surface water and groundwater samples has been developed. Caffeine is extracted from a 1 L water sample with a 0.5 g graphitized carbon-based solid-phase cartridge, eluted with methylene chloride-methanol (80 + 20, v/v), and analyzed by liquid chromatography with photodiode-array detection. The single-operator method detection limit for organic-free water samples was 0.02 ??g/L. Mean recoveries and relative standard deviations were 93 ?? 13% for organicfree water samples fortified at 0.04 ??g/L and 84 ?? 4% for laboratory reagent spikes fortified at 0.5 ??g/L. Environmental concentrations of caffeine ranged from 0.003 to 1.44 ??g/L in surface water samples and from 0.01 to 0.08 ??g/L in groundwater samples.

  12. Micro-solid phase extraction coupled with high-performance liquid chromatography-tandem mass spectrometry for the determination of stimulants, hallucinogens, ketamine and phencyclidine in oral fluids.

    Science.gov (United States)

    Sergi, Manuel; Compagnone, Dario; Curini, Roberta; D'Ascenzo, Giuseppe; Del Carlo, Michele; Napoletano, Sabino; Risoluti, Roberta

    2010-08-24

    A confirmatory method for the determination of illicit drugs based on micro-solid phase extraction with modified tips, made of a functionalized fiberglass with apolar chains of octadecylsilane into monolithic structure, has been developed in this study. Drugs belonging to different chemical classes, such as amphetamine, methamphetamine, methylenedioxyamphetamine, methylenedioxyethylamphetamine, methylenedioxymethylamphetamine, cocaine, benzoylecgonine, ketamine, mescaline, phencyclidine and psilocybine were analyzed. The quantitation was performed by liquid chromatography-tandem mass spectrometry and the analytes were detected in positive ionization by means of an electrospray source. The limits of quantification ranged between 0.3 ng mL(-1) for cocaine and 4.9 ng mL(-1) for psilocybine, with coefficients of determination (r(2)) >0.99 for all the analytes as recommended in the guidelines of Society of Forensic Toxicologists-American Association Forensic Sciences. PMID:20800724

  13. Chromium and iron determinations in food and herbal plant samples by atomic absorption spectrometry after solid phase extraction on single-walled carbon nanotubes (SWCNTs) disk.

    Science.gov (United States)

    Soylak, Mustafa; Unsal, Yunus Emre

    2010-06-01

    A preconcentration-separation procedure has been established based on solid phase extraction of Fe(III) and Cr(III) on single-walled carbon nanotubes (SWCNTs) disk. The analyte ions were quantitatively recovered at pH 8.0 on single-walled carbon nanotubes disk that contains 30 mg of nanotube. The influences of matrix components were tolerable. The detection limits for iron and chromium were calculated as 2.12 and 4.08 microg/l, respectively. The presented method was validated by the analysis of lichen (IAEA-336), CRM025-050 Metals on soil and BCR-032 Moroccan Phosphate rock certified reference materials. The method was successfully applied to the preconcentration and separation of iron and chromium in some food and herbal plant samples from Turkey. PMID:20304024

  14. Determination of etoricoxib in human plasma using automated on-line solid-phase extraction coupled with LC-APCI/MS/MS

    Scientific Electronic Library Online (English)

    Sérgio Luiz, Dalmora; Liberato, Brum Junior; Ricardo Machado, Ferretto; Paulo Renato de, Oliveira; Thiago, Barth; Maximiliano da Silva, Sangoi.

    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.

  15. Direct modification of hydrogen/deuterium-terminated diamond particles with polymers to form reversed and strong cation exchange solid phase extraction sorbents.

    Science.gov (United States)

    Yang, Li; Jensen, David S; Vail, Michael A; Dadson, Andrew; Linford, Matthew R

    2010-12-01

    We describe direct polymer attachment to hydrogen and deuterium-terminated diamond (HTD and DTD) surfaces using a radical initiator (di-tert-amyl peroxide, DTAP), a reactive monomer (styrene) and a crosslinking agent (divinylbenzene, DVB) to create polystyrene encapsulated diamond. Chemisorbed polystyrene is sulfonated with sulfuric acid in acetic acid. Surface changes were followed by X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and diffuse reflectance Fourier transform infrared spectroscopy (DRIFT). Finally, both polystyrene-modified DTD and sulfonated styrene-modified DTD were used in solid phase extraction (SPE). Percent recovery and column capacity were investigated for both phenyl (polystyrene) and sulfonic acid treated polystyrene SPE columns. These diamond-based SPE supports are stable under basic conditions, which is not the case for silica-based SPE supports. PMID:21047639

  16. Selective separation and preconcentration of copper (II) in environmental samples by the solid phase extraction on multi-walled carbon nanotubes

    International Nuclear Information System (INIS)

    A solid phase extraction method for selective separation-preconcentration of copper (II) on multi-walled carbon nanotubes (MWNTs) prior to its flame atomic absorption spectrometric determinations has been investigated. The adsorption was achieved quantitatively on MWNTs column at pH 7.0, then the retained Cu(II) contents on the column were quantitatively eluted with 2 M HNO3. The effects of analytical parameters including pH of the solution, eluent type, sample volume, flow rates of eluent, matrix ions etc. were investigated for optimization of the presented procedure. The preconcentration factor was 60. The detection limit for copper (II) was found as 1.46 ?g/L. The method was applied to the determination of copper in environmental samples and reproducible results were obtained.

  17. 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.

  18. Preconcentration of Nd, Eu and Lu by using 5,7-dichloroquinoline-8-ol modified naphthalene as solid phase extractant material

    International Nuclear Information System (INIS)

    The preparation of solid reagent 5,7-dichloroquinoline-8-ol functionalized naphthalene for preconcentration of Nd, Eu and Lu is described. This material enriches Nd, Eu and Lu quantitatively from dilute aqueous and synthetic sea water solutions in the pH range 8.0 ± 0.2. The solid mixture consisting of the enriched metal ion along with the solid phase extractant were dissolved in 5 ml of DMF and individual Rare Earth Element (REE) content was established by Flame Atomic Absorption Spectrometry. The detection limits (corresponding to 3 times the standard deviation of blank) and enrichment factor were found to be 40, 4.0 and 30 ?g/l and 200, 200 and 200 for Nd, Eu and Lu respectively. The Nd, Eu and Lu contents in sea water was established by ICP-MS in conjunction with the above developed preconcentration procedure. (author)

  19. A novel solid phase extraction--ultra high performance liquid chromatography-tandem mass spectrometry method for the quantification of ochratoxin A in red wines.

    Science.gov (United States)

    Mariño-Repizo, Leonardo; Kero, Frank; Vandell, Victor; Senior, Adam; Isabel Sanz-Ferramola, M; Cerutti, Soledad; Raba, Julio

    2015-04-01

    A novel and advanced technology on solid phase extraction column prior to liquid chromatography coupled to tandem mass spectrometry has been used for the determination of ochratoxin A in red wine samples. Due to the need of a reliable and rugged method according to current regulations and with the aim of minimize heuristic efforts associated with analytical method development, the statistical design of experiment was employed. On other hand, the method validation according to European Commission 2002/657/EC was achieved. The values obtained for decision limit (CC?), detection capability (CC?), limits of detection and quantification were 0.07 ?g L(-1), 0.14 ?g L(-1), 0.13 ?g L(-1) and 0.41 ?g L(-1), respectively. The recoveries values were ranged from 95.7% to 107.2%. These values were compatible with the 2.0 ?g L(-1) maximum allowable concentration limit established by different international regulations. PMID:25442604

  20. 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.

  1. Definitive Screening Design Optimization of Mass Spectrometry Parameters for Sensitive Comparison of Filter and Solid Phase Extraction Purified, INLIGHT Plasma N-Glycans.

    Science.gov (United States)

    Hecht, Elizabeth S; McCord, James P; Muddiman, David C

    2015-07-21

    High-throughput, quantitative processing of N-linked glycans would facilitate large-scale studies correlating the glycome with disease and open the field to basic and applied researchers. We sought to meet these goals by coupling filter-aided-N-glycan separation (FANGS) to the individuality normalization when labeling with glycan hydrazide tags (INLIGHT) for analysis of plasma. A quantitative comparison of this method was conducted against solid phase extraction (SPE), a ubiquitous and trusted method for glycan purification. We demonstrate that FANGS-INLIGHT purification was not significantly different from SPE in terms of glycan abundances, variability, functional classes, or molecular weight distributions. Furthermore, to increase the depth of glycome coverage, we executed a definitive screening design of experiments (DOE) to optimize the MS parameters for glycan analyses. We optimized MS parameters across five N-glycan responses using a standard glycan mixture, translated these to plasma and achieved up to a 3-fold increase in ion abundances. PMID:26086806

  2. Fluorinated carbon tag derivatization combined with fluorous solid-phase extraction: a new method for the highly sensitive and selective mass spectrometric analysis of glycans.

    Science.gov (United States)

    Li, Lulu; Jiao, Jing; Cai, Yan; Zhang, Ying; Lu, Haojie

    2015-05-19

    The sensitive and specific detection of glycans via mass spectrometry (MS) remains a significant challenge due to their low abundance in complex biological mixtures, inherent lack of hydrophobicity, and suppression by other, more abundant biological molecules (proteins/peptides) or contaminants. A new strategy for the sensitive and selective MS analysis of glycans based on fluorous chemistry is reported. Glycan reducing ends were derivatized with a hydrophobic fluorinated carbon tag, increasing glycan ionization efficiency during MS by more than an order of magnitude. More importantly, the fluorinated carbon tag enabled efficient fluorous solid-phase extraction (FSPE) to specifically enrich the glycans from contaminated solutions and protein mixtures. Finally, we successfully analyzed the N-glycome in human serum using this new method. PMID:25884104

  3. Speciation analysis of organotin compounds in human urine by headspace solid-phase micro-extraction and gas chromatography with pulsed flame photometric detection.

    Science.gov (United States)

    Valenzuela, Aníbal; Lespes, Gaëtane; Quiroz, Waldo; Aguilar, Luis F; Bravo, Manuel A

    2014-07-01

    A new headspace solid-phase micro-extraction (HS-SPME) method followed by gas chromatography with pulsed flame photometric detection (GC-PFPD) analysis has been developed for the simultaneous determination of 11 organotin compounds, including methyl-, butyl-, phenyl- and octyltin derivates, in human urine. The methodology has been validated by the analysis of urine samples fortified with all analytes at different concentration levels, and recovery rates above 87% and relative precisions between 2% and 7% were obtained. Additionally, an experimental-design approach has been used to model the storage stability of organotin compounds in human urine, demonstrating that organotins are highly degraded in this medium, although their stability is satisfactory during the first 4 days of storage at 4 °C and pH=4. Finally, this methodology was applied to urine samples collected from harbor workers exposed to antifouling paints; methyl- and butyltins were detected, confirming human exposure in this type of work environment. PMID:24840433

  4. Preconcentration of trace manganese from natural waters by complexation with dithiocarbamate and adsorption onto C18-solid phase extraction column for neutron activation analysis

    International Nuclear Information System (INIS)

    A method was developed for the preconcentration and separation of trace manganese from natural water samples by complexation with dithiocarbamate followed by adsorption onto C18-solid phase extraction column prior to irradiation. The Mn recovery was better than 99.8% without interference from iron(III) at 5 mg x l-1, copper(II), zinc(II), aluminum(III) and cobalt(II) at 0.5 mg x l-1 and sodium(I), potassium(I), magnesium(II) and calcium(II) at 1 mg x l-1. The separation factor was 100 and the detection limit was 0.01 ?g x l-1 with good precision and accuracy with a relative error lower than 3%. The method was applied to the determination of Mn in tap, well, river and treated water samples. (author)

  5. Headspace (HS et micro-extraction en phase solide (SPME. Théorie et applications Headspace (HS and solid phase micro-extraction (SPME. Theory and applications

    Directory of Open Access Journals (Sweden)

    Mura Patrick

    2010-08-01

    Full Text Available Les techniques headspace et la micro-extraction en phase solide sont individuellement des modes de préparation d’échantillon très utilisés dans de nombreux domaines industriels et en biologie. Leur association permet d’augmenter la sensibilité des analytes recherchés et quantifiés et ainsi d’abaisser les limites de quantification et de détection. La technique headspace ou espace de tête est basée sur la volatilité de l’analyte recherché dans une matrice complexe non chromatographiable. Elle peut prendre deux aspects, soit statique, où le prélèvement se fait dans l’espace de tête directement avec un volume constant, soit dynamique après piégeage de l’analyte sur un support que l’on désorbe par un choc thermique. La micro-extraction permet de piéger des analytes avec une aiguille rétractable recouverte d’une phase adaptée aux analytes dans un milieu ambiant ou confiné (par exemple un espace de tête. Cette aiguille est introduite à l’intérieur d’un injecteur et les analytes sont désorbés thermiquement ou élués en fonction de la technique analytique utilisée. Deux applications sont présentées : le dosage des alcools dans le sang total et le suivi des esters d’éthyle dans le whisky. La diversité de ces deux exemples illustre bien l’écclectisme de ces deux types de préparation d’échantillon. Il s’agit donc de deux méthodes de préparation simples et rapides qui permettent de doser les substances volatiles. Associées, elles permettent d’augmenter la sensibilité et donc d’abaisser les limites de quantification et de détection. Headspace and solid phase micro-extraction are two methods of sample preparation widely used in industrial fields and biology. Their combination helps to increase the sensitivity of analytes and consequently to obtain lower limits of quantification and detection. The headspace technique is based on the volatility of the analyte present in a complex matrix. It can take two forms, either static where the volatil analyte is sampled directly in the headspace with a constant volume or dynamic after trapping the analyte on a support which is desorbed by thermic shock. The micro-extraction allows trapping of analytes with a retractable needle covered with a suitable phase in a confined environment (such as headspace. The needle is inserted inside an injector and the analytes are thermally desorbed or eluted according to the analytical technique used. Two applications are presented: the determination of various alcohols in whole blood and the monitoring of ethyl esters in whiskey. The diversity of these two examples illustrates the eclecticism of these two types of sample preparation. Both preparation methods allow simple and rapid assay of volatile substances. Combined, they can increase the sensitivity and therefore lower limits of quantification and detection are observed.

  6. 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.

  7. 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.

    1098-11-01

    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.

  8. Determination of sulfadiazine in phosphate- and DOC-rich agricultural drainage water using solid-phase extraction followed by liquid chromatography-tandem mass spectrometry

    DEFF Research Database (Denmark)

    Bouyou, P.A. Léon; Weisser, Johan Juhl

    2014-01-01

    Trace levels of the veterinary antibiotic compound sulfadiazine (SDZ) can be determined in agricultural drainage water samples with this new method. Optimized sample pretreatment and solid-phase extraction was combined with liquid chromatography coupled to tandem mass spectrometry (SPE LC-MS/MS) using positive electrospray ionization. The linear dynamic range for the LC-MS/MS was assessed from 5 ?g/L to 25 mg/L with a 15-point calibration curve displaying a coefficient of correlation r2=0.9915. Agricultural drainage water spiked at a concentration of 25 ng/L gave recoveries between 63 and 98% (relative standard deviation 15%), while at 10 ng/L, it showed a lower recovery of 32% (relative standard deviation 47%). The final SPE LC-MS/MS method had a limit of detection (LOD)Method and a limit of quantification (LOQ)Method of 7.5 and 23 ng/L agricultural drainage water, respectively. Determination of SDZ, spiked at a realistic concentration of 50 ?g/L, in artificial drainage water (ADW) containing common and high levels of phosphate (0.05, 0.5, and 5 mg/L) gave recoveries between 70 and 92% (relative standard deviation 7.4–12.9%). Analysis of the same realistic concentration of SDZ in ADW, spiked with common and high levels of dissolved organic carbon (2, 6, and 15 mg/L) confirmed the possible adaptation of a tandem solid-phase extraction (strong anion exchange (SAX)-hydrophilic-lipophilic balance (HLB)) followed by liquid chromatography-tandem mass spectrometry methodology.

  9. 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

  10. Determination of mitragynine in plasma with solid-phase extraction and rapid HPLC-UV analysis, and its application to a pharmacokinetic study in rat.

    Science.gov (United States)

    Parthasarathy, Suhanya; Ramanathan, Surash; Ismail, Sabariah; Adenan, Mohd Ilham; Mansor, Sharif Mahsufi; Murugaiyah, Vikneswaran

    2010-07-01

    A new solid phase extraction method for rapid high performance liquid chromatography-UV determination of mitragynine in plasma has been developed. Optimal separation was achieved with an isocratic mobile phase consisting of acetonitrile-ammonium acetate buffer, 50 mM at pH 5.0 (50:50, v/v). The method had limits of detection and quantification of 0.025 and 0.050 microg/mL, respectively. The method was accurate and precise for the quantitative analysis of mitragynine in human and rat plasma with within-day and between-day accuracies between 84.0 and 109.6%, and their precision values were between 1.7 and 16.8%. Additional advantages over known methods are related to the solid phase extraction technique for sample preparation which yields a clean chromatogram, a short total analysis time, requires a smaller amount of plasma samples and has good assay sensitivity for bioanalytical application. The method was successfully applied in pharmacokinetic and stability studies of mitragynine. In the present study, mitragynine was found to be fairly stable during storage and sample preparation. The present study showed for the first time the detailed pharmacokinetic profiles of mitragynine. Following intravenous administration, mitragynine demonstrated a biphasic elimination from plasma. Oral absorption of the drug was slow, prolonged and was incomplete, with a calculated absolute oral bioavailability value of 3.03%. The variations observed in previous pharmacokinetic studies after oral administration of mitragynine could be attributed to its poor bioavailability rather than to the differences in assay method, metabolic saturation or mitragynine dose. PMID:20454783

  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. 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 de 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...

  13. 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.

  14. Multiresidue method for determination of 90 pesticides in fresh fruits and vegetables using solid-phase extraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Stajnbaher, Darinka; Zupancic-Kralj, Lucija

    2003-10-10

    A multiresidue method for analysis of 90 pesticides with different physico-chemical properties in fruits and vegetables was developed. The method involves a rapid and small-scale extraction procedure with acetone using vortex mixing. Solid-phase extraction (SPE) on a highly cross-linked polystyrene divinylbenzene column (LiChrolut EN) was used for clean-up and pre-concentration of the pesticides from the water-diluted acetone extracts. For most fruit and vegetable samples this partial clean-up was sufficient, but some of them with more co-extracting substances need further clean-up (cereals, spinach, carrots, etc.). Diethylaminopropyl (DEA) modified silica was used for efficient removal of interferences caused by various organic acids, sugars, etc. The pesticide residues were determined by gas chromatography with a mass selective detector (GC-MS). The majority of pesticide recoveries for various fruits and vegetables were >80% in the concentration range from 0.01 to 0.50 mg/kg, except for the most polar pesticides (methamidophos, acephate, omethoate) which cannot be determined by this method. The limit of quantitation for most of the pesticides was 0.01 mg/kg with majority of relative standard deviations (R.S.D.s) below 10%. PMID:14570330

  15. Optimization and application of headspace-solid-phase micro-extraction coupled with gas chromatography-mass spectrometry for the determination of volatile compounds in cherry wines.

    Science.gov (United States)

    Xiao, Zuobing; Zhou, Xuan; Niu, Yunwei; Yu, Dan; Zhu, Jiancai; Zhu, Guangyong

    2015-01-26

    A simple, rapid and solvent-free multi-residue method has been developed and applied to confirm and quantify a series of volatile compounds in five cherry wines by gas chromatography coupled with mass spectrometry (GC-MS). Four parameters (e.g., coating material of fiber, temperature and time of extraction, and addition of sodium chloride in the solution) of headspace solid-phase micro-extraction (HS-SPME) were optimized, resulting in the best extraction condition including 50/30 ?m DVB/CAR/PDMS fiber, 45 min and 50 °C of SPME, and 2g of sodium chloride addition in the wine during the extraction. The SPME had LODs and LOQs ranging from 0.03 to 7.27 ?g L(-1) and 0.10 to 24.24 ?g L(-1) for analytic compounds, respectively. Repeatability and reproducibility values were all below 19.8%, with mean values of 12.7% and 10.5%, respectively. Regression coefficients (R(2)) of detective linearity of the standard curves was higher than 0.9852. Moreover, relative recoveries of analytical targets were achieved in a range of 60.7-125.6% with good relative standard deviation values (?20.6%). In addition, a principal component analysis (PCA) was used to analyze the aroma profiles of the wines, which indicated that five samples were distinctly divided into two groups based on their different geographical origins and volatile compounds. PMID:25544009

  16. Determination of organophosphorus flame retardants in fish by pressurized liquid extraction using aqueous solutions and solid-phase microextraction coupled with gas chromatography-flame photometric detector.

    Science.gov (United States)

    Gao, Zhanqi; Deng, Yuehua; Yuan, Wenting; He, Huan; Yang, Shaogui; Sun, Cheng

    2014-10-31

    A novel method was developed for the determination of organophosphorus flame retardants (PFRs) in fish. The method consists of a combination of pressurized liquid extraction (PLE) using aqueous solutions and solid-phase microextraction (SPME), followed by gas chromatography-flame photometric detector (GC-FPD). The experimental parameters that influenced extraction efficiency were systematically evaluated. The optimal responses were observed by extracting 1g of fish meat with the solution of water:acetonitrile (90:10, v/v) at 150°C for 5min and acid-washed silica gel used as lipid sorbent. The obtained extract was then analyzed by SPME coupled with GC-FPD without any additional clean-up steps. Under the optimal conditions, the proposed procedure showed a wide linear range (0.90-5000ngg(-1)) obtained by analyzing the spiked fish samples with increasing concentrations of PFRs and correlation coefficient (R) ranged from 0.9900 to 0.9992. The detection limits (S/N=3) were in the range of 0.010-0.208ngg(-1) with standard deviations (RSDs) ranging from 2.0% to 9.0%. The intra-day and inter-day variations were less than 9.0% and 7.8%, respectively. The proposed method was successfully applied to the determination of PFRs in real fish samples with recoveries varying from 79.8% to 107.3%. The results demonstrate that the proposed method is highly effective for analyzing PFRs in fish samples. PMID:25282313

  17. 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

  18. A new approach to the application of solid phase extraction disks with LC-MS/MS for the analysis of drugs on a 96-well plate format.

    Science.gov (United States)

    Cudjoe, Erasmus; Pawliszyn, Janusz

    2009-11-01

    A new 96-well disk solid phase extraction sample preparation technique which does not involve vacuum pumps integrated with liquid chromatographic tandem mass spectrometric (LC-MS/MS) was developed for high throughput determination of benzodiazepines (nordiazepam, diazepam, lorazepam and oxazepam). In addition, the method completely allows the re-use of the SPE disk membranes for subsequent analyses after re-conditioning. The method utilizes a robotic autosampler for parallel extractions in a 96-well plate format. Results have been presented for independent extractions from three matrices; phosphate buffer solution, urine, and plasma. Factors affecting data reproducibility, extraction kinetics, sample throughput, and reliability of the system were investigated and optimized. A total time required per sample was 0.94 min using 96-well format. Method reproducibility was < or =9% relative standard deviation for all three matrices. Limits of detection and quantitation recorded were respectively in the range 0.02-0.15 and 0.2-2.0 ng/mL with linearity ranging from 0.2 to 500 ng/mL for all matrices. PMID:18771872

  19. Quantitative determination of phenothiazine derivatives in human plasma using monolithic silica solid-phase extraction tips and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Kumazawa, Takeshi; Hasegawa, Chika; Uchigasaki, Seisaku; Lee, Xiao-Pen; Suzuki, Osamu; Sato, Keizo

    2011-05-01

    Solid-phase extraction (SPE) using micropipette tips is a useful technique to prepare samples prior to mass spectrometry. However, most commercial SPE tips have loading capacities that are insufficient for quantitative determination. In this paper, we describe a rapid method for quantitative microanalysis of five phenothiazine derivatives, chlorpromazine, levomepromazine, promazine, promethazine and trimeprazine, using a recently introduced C(18) monolithic silica SPE tip, the MonoTip C(18), for extraction from human plasma. The drugs could be extracted within 5 min from 0.1-mL plasma samples, eluted with methanol, and the eluate injected directly into a gas chromatograph prior to mass spectrometry analysis. Only 0.7 mL of solvent was required for each step of the extraction process. The recoveries of the five phenothiazines spiked into plasma were 91-95% and the limits of quantification for each drug were between 0.25 and 2.0 ng/0.1 mL. The maximum intra- and inter-day coefficient of variation was 11%. The validated method was successfully used to quantify the plasma concentration of levemepromazine in a human subject after oral administration of the drug. This new method is expected to have wide applications as a pretreatment for the rapid, quantitative determination of drug concentrations in plasma samples. PMID:21429493

  20. Dispersive micro-solid-phase extraction of herbicides in vegetable oil with metal-organic framework MIL-101.

    Science.gov (United States)

    Li, Na; Zhang, Liyuan; Nian, Li; Cao, Bocheng; Wang, Zhibing; Lei, Lei; Yang, Xiao; Sui, Jiaqi; Zhang, Hanqi; Yu, Aimin

    2015-03-01

    Dispersive microsolid-phase extraction based on metal-organic framework has been developed and applied to the extraction of triazine and phenylurea herbicides in vegetable oils in this work. The herbicides were directly extracted with MIL-101 from diluted vegetables oils without any further cleanup. The separation and determination of herbicides were carried out on high performance liquid chromatography. The effects of experimental parameters, including volume ratio of n-hexane to oil sample, mass of MIL-101, extraction time, centrifugation time, eluting solvent, and elution time were investigated. The Student's t test was applied to evaluate the selected experimental conditions. The limits of detection for the herbicides ranged from 0.585 to 1.04 ?g/L. The recoveries of the herbicides ranged from 87.3 to 107%. Our results showed that the present method is rapid, simple, and effective for extracting herbicides in vegetable oils. PMID:25665636

  1. Solid phase extraction and spectrophotometric determination of mercury by adsorption of its diphenylthiocarbazone complex on an alumina column

    Science.gov (United States)

    Rajesh, N.; Gurulakshmanan, G.

    2008-02-01

    A simple method has been developed for the preconcentration of mercury based on the adsorption of its diphenylthiocarbazone complex on a neutral alumina column. The influence of acidity, eluting agents, stability of the column, sample volume and interfering ions has been investigated in detail. The adsorbed complex could be eluted using environmentally benign polyethylene glycol (PEG 400) and the concentration of mercury was determined by visible spectrophotometry at a wavelength maximum of 520 nm. A detection limit of 4 ?g L -1 could be achieved and the developed procedure was successfully applied for the determination of mercury in spiked water samples and city waste incineration ash (CRM176). The preconcentration factor attainable for quantitative recovery (>95%) of mercury(II) was 100 for a 1000 mL sample volume.

  2. Simultaneous determination of the antipsychotic drugs levomepromazine and clozapine and their main metabolites in human plasma by a HPLC-UV method with solid-phase extraction.

    Science.gov (United States)

    Mercolini, Laura; Bugamelli, Francesca; Kenndler, Ernst; Boncompagni, Giancarlo; Franchini, Livia; Raggi, Maria Augusta

    2007-02-01

    A HPLC method with UV detection has been developed for the simultaneous determination of levomepromazine, clozapine and their main metabolites: N-desmethyl-levomepromazine, levomepromazine sulphoxide, O-desmethyl-levomepromazine, N-desmethylclozapine and clozapine N-oxide. The analytes were separated on a C8 reversed-phase column using a mobile phase composed of acetonitrile and a pH 2.0, 34 mM phosphate buffer containing 0.3% triethylamine (29:71, v/v). Loxapine was used as the internal standard. A reliable biological sample pre-treatment procedure by means of solid-phase extraction on C1 cartridges was implemented, which allows to obtain good extraction yields (>91%) for all analytes and appropriate sample purification from endogenous interference. The method was validated in terms of extraction yield, precision and accuracy. These assays gave RSD% values for precision always lower than 4.9% and mean accuracy values higher than 92%. The method is suitable for the therapeutic drug monitoring (TDM) of patients undergoing polypharmacy with levomepromazine and clozapine. PMID:17045854

  3. QuEChERS Method Followed by Solid Phase Extraction Method for Gas Chromatographic-Mass Spectrometric Determination of Polycyclic Aromatic Hydrocarbons in Fish

    Science.gov (United States)

    Khorshid, Mona; Souaya, Eglal R.; Hamzawy, Ahmed H.; Mohammed, Moustapha N.

    2015-01-01

    A gas chromatography equipped with mass spectrometer (GCMS) method was developed and validated for determination of 16 polycyclic aromatic hydrocarbons (PAHs) in fish using modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method for extraction and solid phase extraction for sample cleanup to remove most of the coextract combined with GCMS for determination of low concentration of selected group of PAHs in homogenized fish samples. PAHs were separated on a GCMS with HP-5ms Ultra Inert GC Column (30?m, 0.25?mm, and 0.25?µm). Mean recovery ranged from 56 to 115%. The extraction efficiency was consistent over the entire range where indeno(1,2,3-cd)pyrene and benzo(g,h,i)perylene showed recovery (65, 69%), respectively, at 2?µg/kg. No significant dispersion of results was observed for the other remaining PAHs and recovery did not differ substantially, and at the lowest and the highest concentrations mean recovery and RSD% showed that most of PAHs were between 70% and 120% with RSD less than 10%. The measurement uncertainty is expressed as expanded uncertainty and in terms of relative standard deviation (at 95% confidence level) is ±12%. This method is suitable for laboratories engaged daily in routine analysis of a large number of samples. PMID:25873966

  4. QuEChERS Method Followed by Solid Phase Extraction Method for Gas Chromatographic-Mass Spectrometric Determination of Polycyclic Aromatic Hydrocarbons in Fish.

    Science.gov (United States)

    Khorshid, Mona; Souaya, Eglal R; Hamzawy, Ahmed H; Mohammed, Moustapha N

    2015-01-01

    A gas chromatography equipped with mass spectrometer (GCMS) method was developed and validated for determination of 16 polycyclic aromatic hydrocarbons (PAHs) in fish using modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method for extraction and solid phase extraction for sample cleanup to remove most of the coextract combined with GCMS for determination of low concentration of selected group of PAHs in homogenized fish samples. PAHs were separated on a GCMS with HP-5ms Ultra Inert GC Column (30?m, 0.25?mm, and 0.25?µm). Mean recovery ranged from 56 to 115%. The extraction efficiency was consistent over the entire range where indeno(1,2,3-cd)pyrene and benzo(g,h,i)perylene showed recovery (65, 69%), respectively, at 2?µg/kg. No significant dispersion of results was observed for the other remaining PAHs and recovery did not differ substantially, and at the lowest and the highest concentrations mean recovery and RSD% showed that most of PAHs were between 70% and 120% with RSD less than 10%. The measurement uncertainty is expressed as expanded uncertainty and in terms of relative standard deviation (at 95% confidence level) is ±12%. This method is suitable for laboratories engaged daily in routine analysis of a large number of samples. PMID:25873966

  5. Optimization and validation of solid phase micro-extraction (SPME) method for analysis of polycyclic aromatic hydrocarbons in rainwater and stormwater

    Science.gov (United States)

    Rianawati, Elisabeth; Balasubramanian, Rajasekhar

    This paper is about development of a simple and rapid solid-phase microextraction (SPME) method coupled with gas chromatography-mass spectrometry (GC-MS) for the quantitative determination of 16 polycyclic aromatic hydrocarbons (PAHs) in rainwater and stormwater samples. In this study the condition of PAHs extractions using SPME was optimized for achieving high enrichment of the analytes from aqueous samples. This condition was optimized by varying the stirring rate, salt concentration, fiber exposure time, sample pH, and sample temperature consecutively. The analysis revealed that optimal operating conditions occurred at condition of 0.5 M of sodium monochloroacetate, 65 °C, pH 7.0, agitation of 720 rpm, and an extraction time of 60 min. A desorption time of 15 min was shown to eliminate carry-over. The satisfactory linearity, detection limits and a high enrichment factor obtained prove that the method is a sensitive tool for trace level measurement. In the next step, the newly developed SPME-GC-MS method was validated for the analysis of PAHs in rainwater and stormwater samples, which resulted in high extraction recoveries from spiked synthetic rainwater and stormwater samples. This corroborates that the method is feasible for analysis of PAHs in real rainwater and stormwater analysis.

  6. Hybridization of commercial polymeric microparticles and magnetic nanoparticles for the dispersive micro-solid phase extraction of nitroaromatic hydrocarbons from water.

    Science.gov (United States)

    Reyes-Gallardo, Emilia M; Lasarte-Aragonés, Guillermo; Lucena, Rafael; Cárdenas, Soledad; Valcárcel, Miguel

    2013-01-01

    In this article, the combination of commercial polymeric microparticles (OASIS MCX) and cobalt ferrite nanoparticles is evaluated in dispersive micro-solid phase extraction (D-?SPE) for the determination of six nitroaromatic hydrocarbons in water. The high affinity of the polymeric material toward the target analytes as well as the magnetic behavior of cobalt ferrite nanoparticles are combined in a synergic way to developed an efficient and simple D-?SPE approach. The sorptive performance of the hybrid material is compared with that most usual sorbents and the effect of its synthesis steps on the extraction capability is also evaluated in depth. After the optimization of selected variables, D-?SPE method was assessed in terms of linearity, sensitivity, precision and accuracy. The new extraction method allows the determination of the target compounds with limits of detection in the range from 0.12 to 1.26 ?g/L and relative standard deviations lower than 9.6%. The recovery study was performed in two different water samples obtaining percentages from 71 to 103%, which demonstrated the applicability of the hybrid sorbent for the selected analytical problem. PMID:23237711

  7. Determination of Aflatoxin M1 in Milk Powder by Ultrasonic-Assisted Extraction and Dispersive Solid-Phase Clean-up.

    Science.gov (United States)

    Manoochehri, Mahboobeh; Asgharinezhad, Ali Akbar; Safaei, Mahdi

    2015-07-01

    This work describes the application of ultrasound-assisted dispersive solid-phase extraction (UA-DSPE) as a sample preparation approach for aflatoxin M1 (AFM1) and also its subsequent determination by HPLC-fluorescence detection. A Box-Behnken design in combination with response surface methodology was implemented to determine the variables affecting the extraction procedure. The effects of different variables, including type and quantity of clean-up phase, ultrasonication time, ultrasonication temperature, nature and volume of the leaching solvent, were investigated in the optimization study. Primary secondary amine (PSA) and acetonitrile were selected as the clean-up phase and the leaching solvent, respectively. The obtained optimized values were 30 mg of PSA, 10 min ultrasonication time, 32°C ultrasonication temperature and 10 mL of acetonitrile. Under the optimal conditions, the limit of detection and limit of quantification were 0.0012 and 0.0045 µg kg(-1), respectively. The recoveries of the UA-DSPE procedure ranged from 80 to 92%, with relative standard deviations lower than 10% in all cases. Eventually, this method was successfully applied to the extraction of AFM1 in milk powder samples. PMID:25378372

  8. Simultaneous determination of 15 steroidal oral contraceptives in water using solid-phase disk extraction followed by high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Sun, Li; Yong, Wei; Chu, Xiaogan; Lin, Jin-Ming

    2009-07-10

    A rapid, accurate and sensitive method for simultaneous determination of 15 steroidal hormones including four estrogens (estrone, 17beta-estradiol, 17alpha-ethynylestradiol, estriol) and eleven progestogens (17beta-estradiol-3-benzoate, 19-norethindrone, gestodene, levonorgestrel, medroxyprogesterone, cyproterone acetate, megestrol-17-acetate, progesterone, norethindrone acetate, chlormadinone-17-acetate, and hydroxy progesterone caproate) in environmental waters was developed by coupling solid-phase disk extraction (SPDE) to ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) with electrospray ionization. Among three types of extraction tested (C(8) SPDE, C(18) SPDE and C(18) SPE), the most satisfactory result was achieved using C(18) SPDE for its satisfactory recovery (75.6 to 101.4%) and short extraction time (15 min for 1L deionised water). The validity of this method was investigated and good analytical performance for all the analytes was obtained, including low limits of method detection (0.5-3.4 ng/L) and excellent linear dynamic range (1.0-50.0 ng/L). The method was applied to determine the steroidal hormones in 10 environmental waters including tap water, river water, lake water and waste water in Beijing. No progestogen was detected in all samples and estrone, estriol, 17alpha-ethynylestradiol were found in most samples at levels between 1.8 and 127.9 ng/L. PMID:19497575

  9. An accurate and precise high performance liquid chromatography method for the rapid quantification of the novel HIV integrase inhibitor raltegravir in human blood plasma after solid phase extraction

    Science.gov (United States)

    Rezk, Naser L.; White, Nicole; Kashuba, Angela D.M.

    2015-01-01

    The quantification of the HIV integrase inhibitor raltegravir in blood plasma is described using solid phase extraction (SPE) coupled with an accurate high-performance liquid chromatography assay with ultraviolet (UV) detection. The method was validated over the range of 20–10,000ng/mL using simple sample preparation and chromatography. The SPE method was optimized to be selective and highly efficient. The buffer’s ionic strength and pH were optimized for retaining RAL and the internal standard on the column, the percentage of methanol was optimized in the cleaning step to remove unwanted plasma contaminants, and the type and amount of acid was optimized for complete elution of the compounds. This method has no interference with other potentially co-administered antiretrovirals or common drugs. Average recoveries for the extraction method were consistently high: 90% for raltegravir and 90% for the internal standard diazepam. This method was found to be accurate and precise. Within day (n=6) and between day (n=18) accuracies ranged from 97.5% to 104.4%. Within-day (n=6) and between-day (n=18) precision ranged from 1.4% to 3.8%, and from 2.4% to 7.9%, respectively. This is the first published method to use simple UV technology and reliable SPE extraction methodology for the quantification of raltegravir in human plasma. This method can be easily implemented in most bioanalytical laboratories. PMID:18929009

  10. Headspace solid phase microextraction in-situ supercritical fluid extraction coupled to gas chromatography-tandem mass spectrometry for simultaneous determination of perfluorocarboxylic acids in sediments.

    Science.gov (United States)

    Liu, Wen-Lin; Hwang, Bao-Huey; Li, Zu-Guang; Jen, Jen-Fon; Lee, Maw-Rong

    2011-10-28

    Headspace solid phase microextraction (HS-SPME) in-situ supercritical fluid extraction (SFE) was investigated for the determination of trace amounts of perfluorocarboxylic acids (PFCAs) in sediments. Quantitation was performed by using gas chromatography coupled to negative chemical ionization-tandem mass spectrometry (GC-NCI-MS/MS). The optimum conditions of HS-SPME following SFE were obtained using 500 ?L n-butanol as a derivatization reagent in supercritical carbon dioxide with static extraction for 10 min, then dynamic extraction for 20 min at 30 MPa and 70 °C and simultaneous collected with 100 ?m film thickness PDMS fiber. The linear range of proposed method was from 5 to 5000 ng g(-1), with limit of detection ranging from 0.39 to 0.54 ng g(-1) and limit of quantitation ranging from 1.30 to 1.80 ng g(-1). The developed method was successfully applied to analyze PFCAs in sediments from rivers and beach near industrial areas. The concentrations of PFCAs determined are from 282 to 4473 ng g(-1). PMID:21924729

  11. 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.

  12. 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.

  13. 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)

  14. 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)

  15. The use of copper(II) isonicotinate-based micro-solid-phase extraction for the analysis of polybrominated diphenyl ethers in soils

    International Nuclear Information System (INIS)

    Highlights: ? A Cu(4-C5H4N-COO)2(H2O)4-based ?-SPE device was developed for determining PBDEs. ? Extraction parameters for determination of PBDEs using ?-SPE in soils were optimized. ? The ?-SPE showed a high selectivity to PBDEs, especially lower brominated PBDEs. ? The ?-SPE is a promising microextraction technique for monitoring PBDEs in soils. - Abstract: A micro-solid-phase extraction (?-SPE) device was developed by filling copper(II) isonicotinate coordination polymer (Cu(4-C5H4N-COO)2(H2O)4) into a porous polypropylene envelope, and the ?-SPE, coupling with gas chromatography (GC) with a micro-cell electron capture detector (?-ECD), was used for extraction and determination of PBDEs in soils. Variables affecting extraction procedures, including temperature, water volume, extraction time, and desorption time, were investigated in a spiked soil, and the parameters were optimized. Under the optimal experimental conditions, the method detection limits for seven PBDEs (BDE-28, 47, 99, 100, 153, 154, and 183) were in the range of 0.026–0.066 ng g?1, and the reproducibility was satisfactory with the relative standard deviation in range of 1.3–10.1%. Good linear relationship between PBDEs concentrations and GC signals (defined as peak area) was obtained in the range between 0.1 and 200 ng g?1. The recovery of the sevrecovery of the seven PBDEs by ?-SPE varied from 70 to 90%, which was comparable to that determined by accelerated solvent extraction method. Finally, the proposed method was used to determine PBDEs in several field-contaminated soils, and it was suggested that the ?-SPE is a promising alternative microextraction technique for the detection of PBDEs in soils.

  16. 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 ...

  17. ?-cyclodextrin functionalized meso-/macroporous magnetic titanium dioxide adsorbent as extraction material combined with gas chromatography-mass spectrometry for the detection of chlorobenzenes in soil samples.

    Science.gov (United States)

    Zhang, Jiabin; Gan, Ning; Chen, Si; Pan, Muyun; Wu, Dazhen; Cao, Yuting

    2015-07-01

    A high-performance and selective adsorbent was developed for simultaneous extraction of 6 chlorobenzenes residues in soil samples by using magnetic solid phase extraction (MSPE) combined with automated SPE followed by gas chromatography-mass spectrometry (GC-MS). The adsorbent was synthesized by grafting carboxymethyl-?-cyclodextrin (CM-?-CD) on the surface of porous core-shell magnetic Fe3O4@flower like TiO2 microspheres (Fe3O4@fTiO2-CMCD), used as a carrier. The main factors (adsorbent amount, adsorption time, elution solvent, elution volume, and elution flow rate) affecting the extraction efficiency were investigated in detail. The adsorbent exhibited high loading capacity (25.6mgg(-1) for 1,3-dichlorobenzene). This maybe due to meso-/macroporous TiO2 having high specific surface area; as a carrier of the ?-cyclodextrin film, it could obviously increase the number of recognition sites. The newly developed adsorbent also showed good selectivity towards chlorobenzenes based on host-guest interactions between ?-cyclodextrin (on adsorbent's surface) and targets, which can minimize complex matrix interference in soil samples. The proposed method was successfully applied for the analysis of environmental soil samples with recovery ranging from 87.3 to 104.3%. All target compounds showed good linearities with correlation coefficients (r) higher than 0.996. The limits of quantitation for the 6 CBs were 0.03-0.09?gkg(-1). These findings confirmed meso-/macroporous structure Fe3O4@fTiO2-CMCD as a highly effective extraction material for use in trace CB analyses in complex soil samples. PMID:25990351

  18. 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)

  19. On-line coupling of solid-phase extraction to gas chromatography-mass spectrometry to determine musk fragrances in wastewater.

    Science.gov (United States)

    Vallecillos, Laura; Borrull, Francesc; Pocurull, Eva

    2014-10-17

    An on-line coupling solid-phase extraction (SPE) has been developed for the first time to preconcentrate trace amounts of 17 musk fragrances extensively used in personal care products (6 polycyclic musks, 3 nitro musks, 7 macrocyclic musks and 1 polycyclic musk degradation product) from wastewater samples, prior to analysis by gas chromatography and mass spectrometry through an on-column interface. A 10 mm × 2 mm I.D. precolumn packed with Oasis HLB (60 ?m) or C18 (60 ?m) was compared for the optimization of the solid-phase extraction process. The parameters affecting the transfer of the analytes from the precolumn to the GC system (e.g. flow-rate, temperature and solvent vapor exit time) as well as SPE parameters (e.g. sample flow, sample volume, elution solvent, etc.) were optimized. An organic modifier such as methanol was added to the sample before the extraction process to avoid adsorption problems. The use of the MS detector under selected ion monitoring acquisition enabled the analytes to be quantified at low ng L(-1) levels, preconcentrating only 10 mL of sample, and the limits of detection were between 1 and 30 ng L(-1). The method was applied for the determination of musk fragrances in wastewater samples from three urban wastewater treatment plants (WWTPs). The analysis of influent urban wastewater revealed that galaxolide, tonalide and ambrettolide were the most abundant musk compounds with concentrations ranging between 18 ng L(-1) and 45,091 ng L(-1), 852 ng L(-1) and 49,904 ng L(-1) and 507 ng L(-1) and 21,528 ng L(-1) respectively. The remaining musks were present at lower concentrations and two of the macrocyclic musk studied (musk MC4 and civetone) were not detected. The analysis of effluent wastewater showed a decrease in the concentrations of all of the compounds present in influent samples, with the decrease being more significantly in the case of polycyclic and nitro musks than for macrocyclic musks. Only HHCB-lactone remained constant or increased its concentration. PMID:25240651

  20. Molecularly imprinted solid phase extraction for simultaneous determination of ?9-tetrahydrocannabinol and its main metabolites by gas chromatography-mass spectrometry in urine samples.

    Science.gov (United States)

    Nesti?, Marina; Babi?, Sandra; Pavlovi?, Dragana Mutavdži?; Sutlovi?, Davorka

    2013-09-10

    In presented paper analytical method based on solid-phase extraction using molecularly imprinted polymer and gas chromatography-mass spectrometry has been developed and validated for the confirmation of THC, THC-OH and THC-COOH in urine samples. Non-covalent molecularly imprinted polymers of THC-OH were prepared using different functional monomers (methacrylic acid, 4-vinylpyridine, and 2-hydroxyethyl methacrylate), ethylene glycol dimethacrylate as a cross-linker and 2,2'-azobis-isobutyronitrile as an initiator of radical polymerization. Analytes were extracted from urine samples using prepared polymer sorbent with highest binding selectivity and capability. Before extraction, urine samples were hydrolyzed with alkaline. Elution was performed with chloroform:ethyl acetate (60:40, v/v). Dry extracts were silylated with BSTFA+1% TMCS. Detection and quantification were performed using gas chromatography-mass spectrometry in single ion recording mode. The developed method was linear over the range from LOQ to 150 ng mL(-1) for all three analytes. For THC, THC-OH and THC-COOH LOD was 2.5, 1 and 1 ng mL(-1), and LOQ was 3, 2 and 2 ng mL(-1), respectively. The precision, accuracy, recovery and matrix effect were investigated at 5, 25 and 50 ng mL(-1). In the investigated concentration range recoveries were 71.9% for THC, 78.6% for THC-OH and 75.2% for THC-COOH. Matrix effect was not significant (<10%) for all analytes in the concentration range from 5 ng mL(-1) to 50 ng mL(-1). Extraction recovery on non-imprinted polymer was relatively high indicating high non-specific binding. Optimized and validated method was applied to 15 post-mortem urine samples. PMID:23890655

  1. 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.

  2. A METHOD FOR AUTOMATED ANALYSIS OF 10 ML WATER SAMPLES CONTAINING ACIDIC, BASIC, AND NEUTRAL SEMIVOLATILE COMPOUNDS LISTED IN USEPA METHOD 8270 BY SOLID PHASE EXTRACTION COUPLED IN-LINE TO LARGE VOLUME INJECTION GAS CHROMATOGRAPHY/MASS SPECTROMETRY

    Science.gov (United States)

    Data is presented showing the progress made towards the development of a new automated system combining solid phase extraction (SPE) with gas chromatography/mass spectrometry for the single run analysis of water samples containing a broad range of acid, base and neutral compounds...

  3. 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.

  4. Determination of phosphoric acid mono- and diesters in municipal wastewater by solid-phase extraction and ion-pair liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Quintana, José Benito; Rodil, Rosario; Reemtsma, Thorsten

    2006-03-01

    The first analytical method for the determination of 13 phosphoric acid mono- and diesters from aqueous samples is presented. The method consists of solid-phase extraction (SPE) and ion-pair liquid chromatographic separation with tri-n-butylamine coupled to electrospray ionization tandem mass spectrometry in the negative ion mode. Due to a lack of pure standards, only 3 of the 13 esters could be quantified. SPE recoveries ranged from 71 to 112% for di-n-butyl phosphate, diphenyl phosphate, and di-(2-ethylhexyl) phosphate (DEHP) with limits of quantification from 7 to 14 ng/L for 100-mL samples. At analyte concentrations >or=1 microg/L, aqueous samples can be analyzed by direct injection without extraction. In municipal wastewater, six diesters and one monoester were unambiguously identified by comparison with synthesized reference material. DEHP showed highest concentrations of 60 and 5 microg/L in raw and treated wastewater, respectively. The detection of monoethylhexyl phosphate was confirmed by LC-Q-TOF-MS analysis, and it was found at a concentration level comparable to DEHP. Laboratory degradation tests show that phosphoric acid diesters can be formed as intermediates in the microbial degradation of trialkyl phosphates that are being used as flame retardants and plasticizers. PMID:16503618

  5. 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.

  6. Multi-walled carbon nanotubes-dispersive solid-phase extraction combined with nano-liquid chromatography for the analysis of pesticides in water samples.

    Science.gov (United States)

    Asensio-Ramos, María; D'Orazio, Giovanni; Hernandez-Borges, Javier; Rocco, Anna; Fanali, Salvatore

    2011-05-01

    In this work, the simultaneous separation of a group of 12 pesticides (carbaryl, fensulfothion, mecoprop, fenamiphos, haloxyfop, diclofop, fipronil, profenofos, fonofos, disulfoton, nitrofen, and terbufos) by nano-liquid chromatography with UV detection is described. For the analyses, a 100 ?m internal diameter capillary column packed with silica modified with phenyl groups was used. Experimental parameters, including the use of a trapping column for increasing the sensitivity, were optimized and validated. A preliminary study of the applicability of a rapid and practical dispersive solid-phase extraction (DSPE) procedure was developed for the extraction of some of these pesticides (carbaryl, fensulfothion, fenamiphos, fipronil, profenofos, fonofos, disulfoton, nitrofen, and terbufos) from Milli-Q water samples using multi-walled carbon nanotubes (MWCNTs). The method was validated through a recovery study at three different levels of concentration, obtaining limits of detection in the range 0.016-0.067 ?g/L (below European Union maximum residue limits) for the majority of the pesticides. In this work, MWCNTs were reused up to five times, representing an important reduction of the waste of stationary phase. Furthermore, DSPE permitted a clear diminution of the total sample treatment time with respect to conventional SPE. PMID:21461621

  7. Preparation and application of poly(2-amino thiophenol)/MWCNTs nanocomposite for adsorption and separation of cadmium and lead ions via solid phase extraction.

    Science.gov (United States)

    Nabid, Mohammad Reza; Sedghi, Roya; Bagheri, Akbar; Behbahani, Mohammad; Taghizadeh, Mohsen; Abdi Oskooie, Hossein; Heravi, Majid M

    2012-02-15

    A new method which utilizes a multiwalled carbon nanotubes/poly(2-amino thiophenol) nanocomposites as an effective sorbents in solid-phase extraction has been developed for separation and preconcentration of Cd(II) and Pb(II) trace levels in environmental samples. The method is based on the adsorption of heavy metals on macromolecular chains due to sharing an electron pair of N and S groups of conducting polymer with cadmium and lead ions. The results indicate the novel nanocomposite presents a high affinity for heavy metals due to the presence of several good extractive sites (S and N) which are introduced to the synthesized nanocomposite. Some parameters including sample condition such as: pH, flow rate, sample volume, and eluent condition such as: type, volume, and concentration: moreover adsorption capacity of matrix ions was investigated on the recovery of Cd(II) and Pb(II). The maximum adsorption capacity of MWCNTs/P2AT nanocomposite as sorbents at optimum conditions for cadmium and lead ions was found to be 178.7 mg g(-1) and 186.4 mg g(-1), respectively. The detection limits of this method were 0.3 and 1 ng mL(-1) for Cd(II) and Pb(II), respectively. The validation of the presented procedure was checked by reference material analysis. Finally, the presented procedure was applied for determination of Cd(II) and Pb(II) in some environmental samples. PMID:22206975

  8. 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.