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Novel method for the determination of five carbamate pesticides in water samples by dispersive liquid-liquid microextraction combined with high performance liquid chromatography 被引量:10
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作者 Zhi Mei Liu Xiao Huan Zang Wei Hua Liu Chun Wang Zhi Wang 《Chinese Chemical Letters》 SCIE CAS CSCD 2009年第2期213-216,共4页
A novel method for the determination of five carbamate pesticides (metolcarb, carbofuran, carbaryl, isoprocard and diethofencard) in water samples was developed by dispersive liquid-liquid microextraction (DLLME) ... A novel method for the determination of five carbamate pesticides (metolcarb, carbofuran, carbaryl, isoprocard and diethofencard) in water samples was developed by dispersive liquid-liquid microextraction (DLLME) coupled with high performance liquid chromatography-diode array detector (HPLC-DAD). Some experimental parameters that influence the extraction efficiency were studied and optimized to obtain the best extraction results. Under the optimum conditions for the method, the calibration curve was linear in the concentration range from 5 to 1000 ng mL^-1 for all the five carbamate pesticides, with the correlation coefficients (r^2) varying from 0.9984 to 0.9994. Good enrichment factors were achieved ranging from 80 to 177- fold, depending on the compound. The limits of detection (LODs) (S/N = 3) were ranged from 0.1 to 0.5 ng mL^-1. The method has been successfully applied to the analysis of the pesticide residues in environmental water samples. 展开更多
关键词 Carbamate pesticides High performance liquid chromatography Diode array detection dispersive liquid-liquid microextraction Water samples
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Ionic liquid based dispersive liquid-liquid microextraction of aromatic amines in water samples 被引量:13
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作者 Yun Chang Fan Zheng Liang Hu +2 位作者 Mei Lan Chen Chao Shen Tu Yan Zhu 《Chinese Chemical Letters》 SCIE CAS CSCD 2008年第8期985-987,共3页
In this work, a new microextraction method termed ionic liquid based dispersive liquid-liquid microextraction (IL-DLLME) was demonstrated for the extraction of 2-methylaniline, 4-chloroaniline, 1-naphthylamine and 4... In this work, a new microextraction method termed ionic liquid based dispersive liquid-liquid microextraction (IL-DLLME) was demonstrated for the extraction of 2-methylaniline, 4-chloroaniline, 1-naphthylamine and 4-aminobiphenyl in aqueous matrices. After extraction the ionic liquid (IL) phase was injected directly into the high performance liquid chromatography (HPLC) system for determination. Some parameters that might affect the extraction efficiency were optimized. Under the optimum conditions, good linear relationship, sensitivity and reproducibility were obtained. The limits of detection (LOD, S/N = 3) for the four analytes were in the range of 0.45-2.6 μg L^-1. The relative standard deviations (R.S.D., n = 6) were in the range of 6.2-9.8%. This method was applied for the analysis of the real water samples. The recoveries ranged from 93.4 to 106.4%. The main advantages of the method are high speed, high recovery, good repeatability and volatile organic solvent-free. 展开更多
关键词 Ionic liquid (IL) dispersive liquid-liquid microextraction (DLLME) High performance liquid chromatography (HPLC) Aromatic amines
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Dispersive liquid-liquid microextraction,an effective tool for the determination of synthetic cannabinoids in oral fluid by liquid chromatography-tandem mass spectrometry 被引量:4
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作者 Pierpaolo Tomai Alessandra Gentili +3 位作者 Roberta Curini Rossella Gottardo Franco Tagliaro Salvatore Fanali 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2021年第3期292-298,共7页
In the present work,dispersive liquid-liquid microextraction(DLLME)was used to extract six synthetic cannabinoids(JWH-018,JWH-019,JWH-073,JWH-200,or WIN 55,225,JWH-250,and AM-694)from oral fluids.A rapid baseline sepa... In the present work,dispersive liquid-liquid microextraction(DLLME)was used to extract six synthetic cannabinoids(JWH-018,JWH-019,JWH-073,JWH-200,or WIN 55,225,JWH-250,and AM-694)from oral fluids.A rapid baseline separation of the analytes was achieved on a bidentate octadecyl silica hydride phase(Cogent Bidentate C18;4.6 mm×250 mm,4μm)maintained at 37℃,by eluting in isocratic conditions(water:acetonitrile(25:75,V/V)).Detection was performed using positive electrospray ionization-tandem mass spectrometry.The parameters affecting DLLME(pH and ionic strength of the aqueous phase,type and volume of the extractant and dispersive solvent,vortex and centrifugation time)were optimized for maximizing yields.In particular,using 0.5 mL of oral fluid,acetonitrile(1 mL),was identified as the best option,both as a solvent to precipitate proteins and as a dispersing solvent in the DLLME procedure.To select an extraction solvent,a low transition temperature mixture(LTTM;composed of sesamol and chlorine chloride with a molar ratio of 1:3)and dichloromethane were compared;the latter(100μL)was proved to be a better extractant,with recoveries ranging from 73%to 101%by vortexing for 2 min.The method was validated according to the guidelines of Food and Drug Administration bioanalytical methods:intra-day and inter-day precisions ranged between 4%and 18%depending on the spike level and analyte;limits of detection spanned from 2 to 18 ng/mL;matrixmatched calibration curves were characterized by determination coefficients greater than 0.9914.Finally,the extraction procedure was compared with previous methods and with innovative techniques,presenting superior reliability,rapidity,simplicity,inexpensiveness,and efficiency. 展开更多
关键词 microextraction techniques dispersive liquid-liquid microextraction Illicit drugs Synthetic cannabinoids Silica C-based column
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Dispersive Liquid-liquid Microextraction Combined with High-performance Liquid Chromatography for the Determination of Clozapine and Chlorpromazine in Urine 被引量:3
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作者 陈静 熊朝梅 +1 位作者 阮金兰 苏邹 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2011年第2期277-284,共8页
A simple method has been proposed for the determination of clozapine (CLZ) and chlorpromazine (CPZ) in human urine by dispersive liquid-liquid microextraction (DLLME) in combination with high-performance liquid ... A simple method has been proposed for the determination of clozapine (CLZ) and chlorpromazine (CPZ) in human urine by dispersive liquid-liquid microextraction (DLLME) in combination with high-performance liquid chromatography-ultraviolet detector (HPLC-UV). All important variables influencing the extraction efficiency, such as pH, types of the extraction solvent and the disperser solvent and their volume, ionic strength and centrifugation time were investigated and optimized. Under the optimal conditions, the limit of detection (LODs) and quantification (LOQs) of the method were 13 and 39 ng/mL for CLZ, and 2 and 6 ng/mL for CPZ, respectively. The relative standard deviations (RSDs) of the targets were less than 5.1% (C=0.100 μg/mL, n=9). Good linear behaviors over the tested concentration ranges were obtained with the values of R20.999 for the targets. The absolute extraction efficiencies of CLZ and CPZ from the spiked blank urine samples were 98.3% and 97.8%, respectively. The applicability of the technique was validated by analyzing urine samples and the mean recoveries for spiked urine samples ranged from 93.3% to 105.0%. The method was successfully applied for the determination of CLZ and CPZ in real human urine. 展开更多
关键词 dispersive liquid-liquid microextraction CLOZAPINE CHLORPROMAZINE high-performance liquid chromatography human urine
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Utilization of Dispersive Liquid-Liquid Microextraction Coupled with HPLC-UV as a Sensitive and Efficient Method for the Extraction and Determination of Oleanolic Acid and Ursolic Acid in Chinese Medicinal Herbs 被引量:2
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作者 Yaomei Hao Xuan Chen +2 位作者 Shuang Hu Xiaohong Bai Deshuang Gu 《American Journal of Analytical Chemistry》 2012年第10期675-682,共8页
Isomeric triterpenic acids of oleanolic acid (OA) and ursolic acid (UA) both have very low ultraviolet absorption and always exist in the same plant, so the separation and simultaneous determination of them have been ... Isomeric triterpenic acids of oleanolic acid (OA) and ursolic acid (UA) both have very low ultraviolet absorption and always exist in the same plant, so the separation and simultaneous determination of them have been a difficult task. In this study, a sensitive method combining dispersive liquid-liquid microextraction (DLLME) with HPLC-UV was developed for the extraction and determination of OA and UA in traditional Chinese medicinal herbs (CMHs). Variables influencing DLLME such as type and volume of extraction solvent, volume of dispersive solvent, ionic strength, aqueous phase pH, extraction time, centrifugation speed and time, and sample volume were investigated and optimized. Under the optimum conditions, both OA and UA attained favorable extraction efficiencies with enrichment factors 1378 and 933, respectively. The linear dynamic ranges of 0.07 - 30.4 μg?mL–1 for OA and 0.08 - 33.6 μg?mL–1 for UA were obtained with square correlation coefficients of 0.9963. The detection limits of OA and UA were both 0.02 μg?mL–1. The method recoveries ranged between 88.2% - 116.2% for OA and 85.7% - 108.2% for UA with the RSDs (n = 5) lower than 8.6%. The proposed method was successfully applied to concentrate and simultaneously determine these two triterpenic acids in Hedyotis diffusa and Eriobotrya japonica samples. 展开更多
关键词 dispersive liquid-liquid microextraction High Performance Liquid Chromatography Enrichment Factor Triterpenic ACIDS Chinese MEDICINAL HERBS
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Determination of Cobalt in Food, Environmental and Water Samples with Preconcentration by Dispersive Liquid-Liquid Microextraction 被引量:1
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作者 Catalina Bosch Ojeda Fuensanta Sánchez Rojas José Manuel Cano Pavón 《American Journal of Analytical Chemistry》 2012年第2期125-130,共6页
A new method for the determination of cobalt was developed by dispersive liquid-liquid microextraction preconcentra-tion and flame atomic absorption spectrometry. In the proposed approach, 1,5-bis(di-2-pyridyl) methyl... A new method for the determination of cobalt was developed by dispersive liquid-liquid microextraction preconcentra-tion and flame atomic absorption spectrometry. In the proposed approach, 1,5-bis(di-2-pyridyl) methylene thiocarbohydrazide (DPTH) was used as a chelating agent, and chloroform and ethanol were selected as extraction and dispersive solvents. Some factors influencing the extraction efficiency of cobalt and its subsequent determination, including extraction and dispersive solvent type and volume, pH of sample solution, concentration of the chelating agent, and extraction time, were studied and optimized. Under the optimum conditions, a preconcentration factor of 8 was reached. The detection limit for cobalt was 12.4 ng?mL–1, and the relative standard deviation (RSD) was 3.42% (n = 7, c = 100 ng?mL–1). The method was successfully applied to the determination of cobalt in food, environmental and water samples. 展开更多
关键词 COBALT dispersive liquid-liquid microextraction Flame Atomic Absorption Spectrometry Water ENVIRONMENTAL and FOOD Samples
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Evaluation of Response Surface Methodology in Dispersive Liquid-Liquid Microextraction for Lead Determination Using Ionic Liquids
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作者 Behrooz Majidi Farzaneh Shemirani Rouhollah Khani 《American Journal of Analytical Chemistry》 2011年第8期892-901,共10页
This paper describes a dispersive liquid–liquid microextraction (DLLME) procedure using room temperature ionic liquids (RTILs) coupled with flame atomic absorption spectrometry detection with microsample intro-ductio... This paper describes a dispersive liquid–liquid microextraction (DLLME) procedure using room temperature ionic liquids (RTILs) coupled with flame atomic absorption spectrometry detection with microsample intro-duction system capable of quantifying trace amounts of lead. In the proposed approach, ammonium pyr-rolidine dithiocarbamate (APDC) was used as a chelating agent and 1-hexyl-3-methylimmidazolium bis (trifluormethylsulfonyl)imid as an extraction solvent was dissolved in acetone as the disperser solvent. The binary solution was then rapidly injected by a syringe into the water sample containing Pb2+ complex. Some factors influencing the extraction efficiency of Pb2+ and its subsequent determination, including extraction and dispersive solvent type, pH of sample solution, concentration of the chelating agent and salt effect were inspected by a full factorial design to identify important parameters and their interactions. Next, a central composite design was applied to obtain the optimum points of the important parameters. Under the optimum conditions, the limit of detection (LOD) was 0.2 μg/L. The relative standard deviation (R.S.D) was 1.4% for 5 μg/L of Pb2+ (n = 7). The relative recovery of lead in seawater, blood, tomato and black tea samples was measured. 展开更多
关键词 IONIC Liquid dispersIVE liquid-liquid microextraction Microsample INJECTION Experimental Design
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Determination of organochlorine pesticides from juice samples using magnetic biochar-based dispersive micro-solid phase extraction in combination with dispersive liquid-liquid microextraction
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作者 Kero Assefa Ago Shimeles Addisu Kitte Abera Gure 《Emerging Contaminants》 CSCD 2024年第1期126-138,共13页
Analysis of pesticide residue levels in juice beverages is important to ensure safe consumption and avoid global trade concerns associated to pesticide contaminations.A simple,inexpensive and effective method was deve... Analysis of pesticide residue levels in juice beverages is important to ensure safe consumption and avoid global trade concerns associated to pesticide contaminations.A simple,inexpensive and effective method was developed for the determination of organochlorine pesticides(OCPs)in bottled juice drinks using GC-MS.Sample pretreatment was performed using dispersive solid-phase microextraction(D-μ-SPE)for matrix desorption and dispersive liquid-liquid microextraction(DLLME)for analyte enrichment.In this study,an affordable and effective sorbent for the adsorption of OCPs from juice samples was synthesized from avocado seeds mixed with magnetic precursors for D-μSPE.The ground avocado seeds combined with a magnetic precursor nanocomposite were characterized using various instruments including scanning electron microscopy(SEM),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),and Brunauer-Emmett-Teller(BET)analysis.The solution obtained from D-μ-SPE desorption was used as a dispersant for the subsequent DLLME,which made the combination of D-μ-SPE with DLLME much easier.The effectiveness of the method was enhanced by optimizing the influential parameters in both D-μ-SPE and DLLME.Then after,the optimal values were determined for the real sample analysis.Accordingly,there was good linear dynamic range with a coefficient of determination(r2)≥0.9989.The limit of detection and quantification were 0.02–0.69 and 0.06–2.10 ng/L respectively.The method showed high enrichment factors ranging from 96 to 313 with recoveries of 87–100%.Intraday and interday precisions were≤4%.Compared with other reported methods,this method is a one-step,simple,cheap,fast,and environmentally friendly alternative and straightforward method for adsorbing organochlorine pesticides from sample solutions.These results demonstrates the high potential of the proposed method for the extraction and cleanup of contaminants in selected juices and other related samples. 展开更多
关键词 dispersive micro solid phase extraction dispersive liquid-liquid microextraction Juice samples Magnetic biochar Organochlorine pesticides Gas chromatography-mass spectrometry
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Determination of Vanadyl Porphyrins by Liquid-liquid Microextraction and Nano-baskets of p-tert-Calix[4]arene Bearing Di-[N-(X)sulfonye Carboxamide] and Di-(1-propoxy) in Ortho-cone Conformation
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作者 MOKHTARI Bahram POURABDOLLAH Kobra 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2012年第5期807-813,共7页
Dispersive liquid-liquid microextraction technique was introducd to remove the centrifuging step and conduct inclusion microextraction of charged porphyrins by nano-baskets. For nano-baskets of p-tert-calix[4]arene be... Dispersive liquid-liquid microextraction technique was introducd to remove the centrifuging step and conduct inclusion microextraction of charged porphyrins by nano-baskets. For nano-baskets of p-tert-calix[4]arene bearing di-[N-(X)sulfonyl carboxamide] and di-(1-propoxy) in ortho-cone conformation was synthesized and used. The related parameters including ligand concentration, the volume of water disperser, salt effect, and extraction time were optimized. The linear range, detection limit(S/N=3) and precision(RSD, n=6) were determined to be 0.2―50, 0.07 μg/L and 5.3%, respectively. The results reveal that the new approach is competitive analytical tool and an alternative of the traditional methods in the crude oil and related systems. 展开更多
关键词 NANO-BASKET dispersive liquid-liquid microextraction Vanadyl porphyrin CALIX[4]ARENE
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A novel method for the determination of trace copper in cereals by dispersive liquid-liquid microextraction based on solidification of floating organic drop coupled with flame atomic absorption spectrometry 被引量:5
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作者 Chun Xia Wu Qiu Hua Wu Chun Wang Zhi Wang 《Chinese Chemical Letters》 SCIE CAS CSCD 2011年第4期473-476,共4页
A novel,simple,rapid,efficient and environment-friendly method for the determination of trace copper in cereal samples was developed by using dispersive liquid-liquid microextraction based on solidification of floatin... A novel,simple,rapid,efficient and environment-friendly method for the determination of trace copper in cereal samples was developed by using dispersive liquid-liquid microextraction based on solidification of floating organic drop(DLLME-SFO) followed by flame atomic absorption spectrometry.In the DLLME-SFO,copper was complexed with 8-hydroxy quinoline and extracted into a small volume of 1-dodecanol,which is of low density,low toxicity and proper melting point near room temperature. The experimental parameters affecting the extraction efficiency were investigated and optimized.Under the optimum conditions, the calibration graph exhibited linearity over the range of 0.5—500 ng/mL with the correlation coefficient(r) of 0.9996.The enrichment factor was 122 and the limit of detection was 0.1 ng/mL.The method was applied to the determination of copper in the complex matrix samples such as rice and millet with the recoveries for the spiked samples at 5.0 and 10.0 u,g/g falling in the range of 92.0-98.0%and the relative standard deviation of 3.9-5.7%. 展开更多
关键词 dispersive liquid-liquid microextraction based on solidification of floating organic droplet Flame atomic absorption spectrometry Copper Cereal samples
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Orthogonal array optimization of ionic liquid based dispersive liquid-liquid microextraction for toxic anilines in foods 被引量:2
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作者 YANG Peng REN HaiXia +2 位作者 WEI Zheng LIU Xia JIANG ShengXiang 《Science China Chemistry》 SCIE EI CAS 2012年第2期277-284,共8页
A simple and rapid method of ionic liquid based dispersive liquid-liquid microextraction (DLLME) combining with high performance liquid chromatography (HPLC) was developed for the analysis of four toxic anilines i... A simple and rapid method of ionic liquid based dispersive liquid-liquid microextraction (DLLME) combining with high performance liquid chromatography (HPLC) was developed for the analysis of four toxic anilines in flour steamed bread and maize steamed bread. Several possible influential factors such as the type of ionic liquid and disperser solvent, extraction time, sample pH, ionic strength and the volume of ionic liquid and disperser solvent were optimized using single factor experiments and orthogonal array design (OAD) with OA25(54) matrix. Analysis of variance (ANOVA) and percent contribution (PC) were used to investigate the significance of the factors of OAD. Sample pH and ionic strength are statistically demonstrated two chief factors. Under the optimum condition, the method exhibits a good linearity (r2 〉 0.99) over the studied range (50-1000 ng g-l) for anilines. The extraction factors and recoveries for the anilines in two kinds of steamed breads ranged between 34.1%-73.3% and 44.3%-95.3%, respectively. The limit of detections (LODs) and limit of quantitations (LOQs) ranged be- tween 10-15 ng g-1 and 30--45 ng g-1. 展开更多
关键词 ANILINE ionic liquid dispersive liquid-liquid microextraction orthogonal array optimization
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Optimization and Application of Liquid Chromatography Determination of Dispersive Liquid-liquid Microextraction Purified Astaxanthin in Shrimp Waste 被引量:2
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作者 ZHU Tao ROW Kyung-ho 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2013年第3期429-433,共5页
A new molecularly imprinted solid-phase extraction(MISPE) monolithic cartridge was synthesized, and MISPE-DLLME(DLLME=dispersive liquid-liquid microextraction) was developed for purification of astaxanthin in shri... A new molecularly imprinted solid-phase extraction(MISPE) monolithic cartridge was synthesized, and MISPE-DLLME(DLLME=dispersive liquid-liquid microextraction) was developed for purification of astaxanthin in shrimp waste. The eluent(methanol) from MISPE was used as the dispersive solvent in subsequent DLLME for further purifying and enriching the analyte prior to high-performance liquid chromatography(HPLC) analysis. The mobile phase was methanol-acetonitrile-water-dichloromethane(85:5:5:5, volume ratio), flow rate was 0.7 mL/min and UV wavelength was 476 nm. Under optimal conditions, good linearity was obtained in a range of 0.2--200.0 lug/mL(r2=0.9998) with a limit of detection(LOD) of 0.08 Hg/mL, and the extraction recoveries at three spiked levels ranged from 88.3%--92.5% with a relative standard deviation(RSD) less than 4.3%. Moreover, the mean contents of astaxanthin in the three batches of shrimp waste were 95.9, 85.4 and 77.2 μg/g, respectively. This method combining the advantages of MISPE and DLLME results in high selectivity and low cost, which was applied to determining the astaxanthin level in shrimp waste samples. 展开更多
关键词 Molecularly imprinted solid-phase extraction dispersive liquid-liquid microextraction ASTAXANTHIN Shrimp waste
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Dispersive Liquid-liquid Microextraction for Simultaneous Determination of Six Parabens in Aqueous Cosmetics
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作者 WEI Hongmin YANG Jinjuan ZHANG Hanqi SHI Yuhua 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2014年第3期368-373,共6页
A simple and rapid sample preparation method of dispersive liquid-liquid microextraction(DLLME) was applied in the simultaneous determination of six parabens in the aqueous cosmetics. The analysis was performed on g... A simple and rapid sample preparation method of dispersive liquid-liquid microextraction(DLLME) was applied in the simultaneous determination of six parabens in the aqueous cosmetics. The analysis was performed on gas chromatography coupled with a flame ionization detection(GC-FID). The mixed solution containing 30 μL of chloroform(extraction solvent) and 300 μL of tetrahydrofuran(dispersive solvent) was rapidly injected into the sample solution for the purpose of microextraction. After that, the solution mentioned above was centrifuged at 4000 r/min for 10 min, and then the organic sediment phase was detected by GC-FID. The effects of experimental parameters, such as the extraction solvent and the volume of it, and the dispersive solvent and the volume of it, on the yield of the extraction were studied in detail. Under the optimum conditions, the enrichment factors of the target analytes range from 87 to 214. Linearity ranges are 0.05-10.0μg/mL for methylparaben and 0.025--5.0 μg/mL for the other five parabens. The relative standard deviations(RSDs) are lower than 8.2%(n=6). The proposed method was applied to the analysis of six parabens in eleven aqueous cosmetics. The recoveries of the target analytes in the spiked real samples are in the range of 81.0%-103%. 展开更多
关键词 dispersive liquid-liquid microextraction PARABENS Aqueous cosmetic Gas chromatography-flame ionization detector
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Determination of multiple drugs of abuse in human urine using dispersive liquid–liquid microextraction and capillary electrophoresis with PDA detection
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作者 Liang Meng Shuhai Ye +1 位作者 Yilin Wu Linda You 《Forensic Sciences Research》 CSCD 2022年第2期265-271,共7页
A new method was developed for pre-concentration and determination of multiple drugs of abuse in human urine using dispersive liquid–liquid microextraction(DLLME)and capillary electrophoresis(CE)with photodiode array... A new method was developed for pre-concentration and determination of multiple drugs of abuse in human urine using dispersive liquid–liquid microextraction(DLLME)and capillary electrophoresis(CE)with photodiode array detection.The method was based on the formation of tiny droplets of an organic extractant in the prepared sample solution using water-immiscible organic solvent(chloroform)dissolved in water-miscible organic dispersive solvent(isopropyl alcohol).The organic phase,which extracted eight drugs of abuse from the prepared urine solution,was separated by centrifugation.The sedimented phase was transferred into a small volume CE auto-sampler vial with 10μL of 1%HCl methanol solution and evaporated to dryness.The residue was reconstituted in lidocaine hydrochloride(internal standard)aqueous solution and introduced by electrokinetic injection into CE.Under the optimum conditions,acceptable linear relationship was observed in the range of 3.0–500 ng/mL with the correlation coefficient(r)of 0.9982–0.9994 for spiked urine samples.The limit of detection(LOD)(S/N=3)was estimated to be 1.0 ng/mL.A recovery of 75.7%–90.6%was obtained for spiked samples.The mean relative error(MRE)was within±7.0%and the relative standard deviation(RSD)was less than 6.9%.The proposed DLLME-CE procedure offers an alternative analytical approach for the sensitive detection of drugs of abuse in real urine samples. 展开更多
关键词 Forensic sciences forensic toxicology dispersive liquid-liquid microextraction capillary electrophoresis drugs of abuse urine sample
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分散液液微萃取-反相液液微萃取-扫集-胶束电动色谱法测定红酒中的3种氯酚类物质 被引量:7
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作者 孙建芝 贺晖 刘书慧 《色谱》 CAS CSCD 北大核心 2014年第3期256-262,共7页
建立了分散液液微萃取(DLLME)-反相液液微萃取(RP-LLME)-扫集-胶束电动色谱富集模型,并用于红酒中五氯酚(PCP)、2,4,6-三氯酚(TCP)和2,4-二氯酚(DCP)3种氯酚的测定。实验考察了两步微萃取的萃取参数对氯酚萃取率的影响和... 建立了分散液液微萃取(DLLME)-反相液液微萃取(RP-LLME)-扫集-胶束电动色谱富集模型,并用于红酒中五氯酚(PCP)、2,4,6-三氯酚(TCP)和2,4-二氯酚(DCP)3种氯酚的测定。实验考察了两步微萃取的萃取参数对氯酚萃取率的影响和样品分离富集的电泳条件。最佳萃取条件 DLLME 为:3.5 mL 红酒( pH 3.0,120 g / L NaCl),300μL 正己烷(萃取剂);RP-LLME 为:25μL 0.16 mol / L NaOH(萃取剂)。最佳电泳条件:25 mmol / L NaH2 PO4,100 mmol / L 十二烷基硫酸钠( SDS),30%( v / v)乙腈,pH 2.3;分离电压-15 kV;样品基质为80 mmol / L NaH2 PO4;压力进样20 s×20.67 kPa(3 psi)。PCP 和 TCP 的线性范围为0.5~100μg / L( r≥0.9910), DCP 的线性范围为1.5~80μg / L(r =0.9851)。3种分析物的检出限( S / N =3)为0.035~0.114μg / L,加标回收率为75.2%~104.7%,相对标准偏差≤6.17%。该方法富集倍数高、灵敏度高、重现性好、分析速度快,可为不同样品基质中痕量氯酚污染物及某些弱酸性有机污染物测定提供参考。 展开更多
关键词 分散液液微萃取 反相液液微萃取 扫集 胶束电动色谱 氯酚 红酒 dispersive liquid-liquid microextraction( DLLME ) reversed phase liquid-liquid microextraction( RP-LLME ) micellar electrokinetic chromatography ( MEKC ) chlorophenols(CPs)
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Ultrasound-Assisted Low-Density Solvent Dispersive Liquid-Liquid Extraction for the Determination of Amphetamines in Biological Samples Using Gas Chromatography-Mass Spectrometry
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作者 Liang Meng Wenwen Zhang +1 位作者 Pinjia Meng Yuxian Liu 《Journal of Forensic Science and Medicine》 2015年第2期114-118,共5页
In order to control drug crime effectively,it is necessary to develop selective analytical methods suitable for unambiguous identification and determination of drugs in illicit samples and biological matrices.A novel ... In order to control drug crime effectively,it is necessary to develop selective analytical methods suitable for unambiguous identification and determination of drugs in illicit samples and biological matrices.A novel microextraction technique based on ultrasound-assisted low-density solvent dispersive liquid-liquid microextraction,(UA-LDS-DLLME)has been applied to the determination of four amphetamines(methamphetamine,amphetamine,3,4-methylenedioxymethamphetamine,and 3,4-methylenedioxyamphetamine)in urine samples by gas chromatography-mass spectrometry.The parameters affecting extraction efficiency have been investigated and optimized.UA-LDS-DLLME used ultrasound energy to assist in the emulsification process without any disperser solvent.Under the optimized conditions,linearity was observed for all analytes in the 0.15-10 p,g/mL range with correlation coefficients(R)ranging from 0.9886 to 0.9894.The recoveries of75.6-91.4%with relative standard deviations of 2.5-4.0%were obtained.The limits of detection(S/N=3)were estimated to be in the 5-10 ng/mL range.The UA-LDS-DLLME technique had the advantages of shorter extraction time,suitability for simultaneous pretreatments of batches of samples,and the higher extraction efficiency.It was successfully applied to the analysis of amphetamines in real human urine samples. 展开更多
关键词 AMPHETAMINES biological samples dispersive liquid-liquid microextraction gas chromatography-mass spectrometry ultrasonication
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