A single-drop liquid phase micro-extraction procedure using 1-butyl-3-methylimidazolium hexafluorophosphate （[C4MIM][PF6]） was demonstrated for the sensitive determination of four phenols in water samples. Under the...A single-drop liquid phase micro-extraction procedure using 1-butyl-3-methylimidazolium hexafluorophosphate （[C4MIM][PF6]） was demonstrated for the sensitive determination of four phenols in water samples. Under the optimized conditions, the linear range of proposed method was excellent in the range of 0.5-100 μg·L^-1, the reproducibility （RSD, n=6） were in the range 5.4%-8.9% and detection limits （S/N=3） were 0.3, 0.3, 0.5 and 0.5 μg·L^-1 for 2, 4-dichlorophenol, 2-naphthol, 2-nitrophenol and 4-chlorophenol, respectively. The experimental results indicated that the effect of complex matrices natural water samples could be resolved with addition of sodium ethylene diamine tetracetate （EDTA） into the samples. Excellent spiked recoveries were achieved for these four phenols ranged from 86.2%-114.9 %. All these facts demonstrated that the proposed method with merits of low cost, simplicity and easy operating would be a competitive alternative procedure for the determination of such compounds at trace level.展开更多
A convenient,cost-effective and fast method using dynamic microwave-assisted extraction and liquid phase microextraction based on the solidification of a floating drop was proposed to analyze organochlorine pesticides...A convenient,cost-effective and fast method using dynamic microwave-assisted extraction and liquid phase microextraction based on the solidification of a floating drop was proposed to analyze organochlorine pesticides in grains including rice,maize and millet.Twelve samples can be processed simultaneously in the method.During the extraction process,10%acetonitrile-water solutions containing 110μL of n-hexadecane were used to extract organochlorine pesticides.Subsequently,1.0 g sodium chloride was placed in the extract,and then centrifuged and cooled.The n-hexadecane drops containing the analytes were solidifi ed and transferred for determination by gas chromatography-electron capture detector without any further filtration or cleaning process.Limits of detection for organochlorine pesticides were 0.97–1.01μg/kg and the RSDs were in the range of 2.6%–8.5%.The developed technology has succeeded in analyzing six real grains samples and the recoveries of the organochlorine pesticides were 72.2%–94.3%.Compared with the published extraction methods,the developed method was used to analyze organochlorine pesticides in grains,being more environmentally friendly,which is suitable for the daily determination of organochlorine pesticides.展开更多
A novel method was described for the rapid determination of atrazine using dispersive liquid phase microextraction in combination with high performance liquid chromatography （HPLC）. Possible impact parameters such a...A novel method was described for the rapid determination of atrazine using dispersive liquid phase microextraction in combination with high performance liquid chromatography （HPLC）. Possible impact parameters such as sample pH, extraction and disperser solvents, salting-out effect, and extraction time were investigated. The experimental results indicated that proposed method possessed an excellent analytical performance, The linear range, detection limit, and precision （R.S.D.） were 0.1- 50 ng mL- 1 （R2 = 0.9955）, 0.601 ng mL- 1 and 6,4%, respectively. The proposed method was validated with the real water samples, and the spiked recoveries were in the range of 69.9-89.8%, respectively. These results indicated that the established method with high enrichment factor, short extraction time was an excellent alternative for the routine analysis of atrazine in environmental samples. 2007 Qing Xiang Zhou. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
A method was established using hollow fiber-liquid phase microextraction（HF-LPME） followed by high performance liquid chromatography（HPLC） to determine the concentration of the free（unbound） drug in the solution...A method was established using hollow fiber-liquid phase microextraction（HF-LPME） followed by high performance liquid chromatography（HPLC） to determine the concentration of the free（unbound） drug in the solution of the drug and protein. Measurements of drug-protein binding ratios and free drug concentrations were then analyzed with the Klotz equation to determine the equilibrium binding constant and number of binding sites for drug-protein interaction. The optimized method allows one to perform the efficient extraction and separation of free drug from protein-bound drug, protein, and other interfering substances. This approach was used to characterize the binding of the anticholinergic drugs atropine sulfate and scopolamine hydrobromide to proteins in human plasma and bovine serum albumin（BSA）. The results demonstrate the utility of HF-LPME method for measuring free drug concentrations in protein-drug mixtures and determining the protein binding parameters of a pharmacologically important class of drugs.展开更多
Hollow fibre cell fishing with HPLC (HFCF-HPLC) based on the human ovarian cancer cell line SKOV-3, human renal tubular cell line ACHN or hepatoma cell line HepG-2 was employed to screen active groups of coumarin and ...Hollow fibre cell fishing with HPLC (HFCF-HPLC) based on the human ovarian cancer cell line SKOV-3, human renal tubular cell line ACHN or hepatoma cell line HepG-2 was employed to screen active groups of coumarin and volatile oil in Radix angelicae sinensis, Radix angelicae dahuricae and Fructus citri sarcodactylis. Simultaneously, hollow fibre liquid phase microextraction with HPLC (HFLPME-HPLC) was conducted to enrich and determine the contents of active components in the same sample solution. Before application, for HFCF-HPLC, cells growth states and survival rates on the fibre, effect of ethanol concentration in the extract of samples on cell survival rates, non-specific binding between fibre active centres and the target components, positive and negative controls and repeatabilities were validated;for HFLPME, extraction solvent, sample phase pH, agitation speed, extraction time and sample phase volume were investigated. Many active components were screened from three medicines. Some of them, such as scoparone, psoralen, bergapten, oxypeucedanin, imperatorin, ligustilide, were identified by MS. The target fishing factors of active components and the cell apoptosis rates of three cells under the medicines effect were researched. The binding sites of active groups on HepG-2 cells were preliminarily determined. The results demonstrated that HFCF-HPLC, coupled with HFLPME-HPLC, is a simple and universal approach to find bioactive components at the cellular level, determine their content and research traditional Chinese medicines (TCMs) entirety effect of multi-component and multi-target. The approach may provide us a new and good solution to clarify the material basis of anti-cancer effect and conduct personalized quality control for the components associated with efficacy in TCMs.展开更多
A novel temperature controlled ionic liquid dispersive liquid phase microextracfion （TCIL-DLPME） coupled with rapid resolution liquid chromatography-electrospray tandem mass spectrometry （RRLC-ESI-MS-MS） has been ...A novel temperature controlled ionic liquid dispersive liquid phase microextracfion （TCIL-DLPME） coupled with rapid resolution liquid chromatography-electrospray tandem mass spectrometry （RRLC-ESI-MS-MS） has been developed for the enrichment and determination of three hexabromocyclododecane diastereomers （HBCDs） in water samples. Green solvent ionic liquid （IL） was used as extraction solvent instead of toxic organic solvents. This technique also avoided the usage of dispersive solvent. Some important parameters that might affect the extraction efficiency were optimized. Under the optimum conditions, good linear relationship, sensitivity and reproducibility were obtained. All the limits of detection for the three diastereomers were 0.1 ng/ mL. The linear range was obtained in the range of 1-100 ng/mL for the total amount of three HBCD diastereomers. It was satisfactory to analyze real environmental water samples with the recoveries ranging from 77.2% to 99.3%. The main advantage of the method is toxic organic solvent-free.展开更多
A rapid,accurate,and sensitive analytical method,ultrasonication-assisted spraying based fine droplet formationeliquid phase microextractionegas chromatographyemass spectrometry(UA-SFDF-LPME-GCMS),was proposed for the...A rapid,accurate,and sensitive analytical method,ultrasonication-assisted spraying based fine droplet formationeliquid phase microextractionegas chromatographyemass spectrometry(UA-SFDF-LPME-GCMS),was proposed for the determination of trace amounts of hydroxychloroquine sulfate in human serum,urine,and saliva samples.To determine the best extraction strategy,several liquid and solid phase extraction methods were investigated for their efficiencies in isolation and preconcentration of hydroxychloroquine sulfate from biological matrices.The UA-SFDF-LPME method was determined to be the best extraction method as it was operationally simple and provided accurate results.Variables such as the extraction solvent,spraying number,sodium hydroxide concentration and volume,sample volume,mixing method,and mixing period were optimized for the proposed method using the onevariable-at-a-time approach.In addition,Tukey’s method based on a post hoc comparison test was employed to evaluate the significant difference between the parameters inspected.After the optimization studies,the limit of detection(LOD)and limit of quantification(LOQ)were determined to be 0.7 and 2.4 mg/kg,respectively.The sensitivity of the GC-MS system based on the LOD was enhanced approximately 440-fold when the UA-SFDF-LPME method was employed.Spiking experiments were also conducted for the human serum,urine,and saliva samples to determine the applicability and accuracy of the proposed method.Recoveries for the human serum,urine,and saliva samples were found to be in the ranges of 93.9%-101.7%,95.2%-105.0%,and 93.1%-102.3%,respectively.These results were satisfactory and indicated that the hydroxychloroquine sulfate level in the above biological samples could be analyzed using the proposed method.展开更多
Microfluidic solvent extraction （micro SX） of gadolinium was conducted using a mono- and diester mixture （MDEHPA） as the cationic extractant. A microfluidic Y-Y channel was fabricated using CO2- laser technique in...Microfluidic solvent extraction （micro SX） of gadolinium was conducted using a mono- and diester mixture （MDEHPA） as the cationic extractant. A microfluidic Y-Y channel was fabricated using CO2- laser technique in a glass microchip used as the extraction system. Compared with batch extraction, extraction kinetic is found fast, and extraction equilibrium is attained within 15 s. Stoichiometry of the extracted complex is found to be Gd（NOs）3-3MDEHPA using log-log plot method. Additionally, the operating parameters and overall volumetric mass transfer coefficient （kLα） were investigated to determine the mass transfer performance. Optimal condition of microextraction for gadolinium using response surface methodology was determined （feed solutions 31 mg/L adjusted to pH value 2.5, extractant concentration 2.9 vol% and extraction time 13.5 s）. In optimal condition, gadolinium extraction yield is obtained 95.5%. Findings of this study approve simplicity, portability, effectiveness, swiftness, and environmental friendliness microfluidic solvent extraction process and reveal that micro SX is useful in the field of extraction strategic metals present at low concentrations, which are otherwise not technically amenable or economically feasible to extract using current traditional methods.展开更多
文摘A single-drop liquid phase micro-extraction procedure using 1-butyl-3-methylimidazolium hexafluorophosphate （[C4MIM][PF6]） was demonstrated for the sensitive determination of four phenols in water samples. Under the optimized conditions, the linear range of proposed method was excellent in the range of 0.5-100 μg·L^-1, the reproducibility （RSD, n=6） were in the range 5.4%-8.9% and detection limits （S/N=3） were 0.3, 0.3, 0.5 and 0.5 μg·L^-1 for 2, 4-dichlorophenol, 2-naphthol, 2-nitrophenol and 4-chlorophenol, respectively. The experimental results indicated that the effect of complex matrices natural water samples could be resolved with addition of sodium ethylene diamine tetracetate （EDTA） into the samples. Excellent spiked recoveries were achieved for these four phenols ranged from 86.2%-114.9 %. All these facts demonstrated that the proposed method with merits of low cost, simplicity and easy operating would be a competitive alternative procedure for the determination of such compounds at trace level.
基金The study was financially supported by the National Science and Technology Support Program of China(Grant No.2013BAD16B08).
文摘A convenient,cost-effective and fast method using dynamic microwave-assisted extraction and liquid phase microextraction based on the solidification of a floating drop was proposed to analyze organochlorine pesticides in grains including rice,maize and millet.Twelve samples can be processed simultaneously in the method.During the extraction process,10%acetonitrile-water solutions containing 110μL of n-hexadecane were used to extract organochlorine pesticides.Subsequently,1.0 g sodium chloride was placed in the extract,and then centrifuged and cooled.The n-hexadecane drops containing the analytes were solidifi ed and transferred for determination by gas chromatography-electron capture detector without any further filtration or cleaning process.Limits of detection for organochlorine pesticides were 0.97–1.01μg/kg and the RSDs were in the range of 2.6%–8.5%.The developed technology has succeeded in analyzing six real grains samples and the recoveries of the organochlorine pesticides were 72.2%–94.3%.Compared with the published extraction methods,the developed method was used to analyze organochlorine pesticides in grains,being more environmentally friendly,which is suitable for the daily determination of organochlorine pesticides.
基金This work was supported by the Personal Innovation Foundation of Universities in Henan Province （No. [2005] 126）； Natural Science Foundation of Henan Province （No. 072300460010） ；the Fund of Henan Normal University （No, 2006PL06）； the grants from the Henan Key Laboratory for environmental pollution control.
文摘A novel method was described for the rapid determination of atrazine using dispersive liquid phase microextraction in combination with high performance liquid chromatography （HPLC）. Possible impact parameters such as sample pH, extraction and disperser solvents, salting-out effect, and extraction time were investigated. The experimental results indicated that proposed method possessed an excellent analytical performance, The linear range, detection limit, and precision （R.S.D.） were 0.1- 50 ng mL- 1 （R2 = 0.9955）, 0.601 ng mL- 1 and 6,4%, respectively. The proposed method was validated with the real water samples, and the spiked recoveries were in the range of 69.9-89.8%, respectively. These results indicated that the established method with high enrichment factor, short extraction time was an excellent alternative for the routine analysis of atrazine in environmental samples. 2007 Qing Xiang Zhou. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
基金Supported by the National Natural Science Foundation of China(No.81041084)the Natural Science Foundation of Shanxi Province, China(No.2007011086)the Undergraduate Innovation Fund of Taiyuan City, China(No.08122034)
文摘A method was established using hollow fiber-liquid phase microextraction（HF-LPME） followed by high performance liquid chromatography（HPLC） to determine the concentration of the free（unbound） drug in the solution of the drug and protein. Measurements of drug-protein binding ratios and free drug concentrations were then analyzed with the Klotz equation to determine the equilibrium binding constant and number of binding sites for drug-protein interaction. The optimized method allows one to perform the efficient extraction and separation of free drug from protein-bound drug, protein, and other interfering substances. This approach was used to characterize the binding of the anticholinergic drugs atropine sulfate and scopolamine hydrobromide to proteins in human plasma and bovine serum albumin（BSA）. The results demonstrate the utility of HF-LPME method for measuring free drug concentrations in protein-drug mixtures and determining the protein binding parameters of a pharmacologically important class of drugs.
文摘Hollow fibre cell fishing with HPLC (HFCF-HPLC) based on the human ovarian cancer cell line SKOV-3, human renal tubular cell line ACHN or hepatoma cell line HepG-2 was employed to screen active groups of coumarin and volatile oil in Radix angelicae sinensis, Radix angelicae dahuricae and Fructus citri sarcodactylis. Simultaneously, hollow fibre liquid phase microextraction with HPLC (HFLPME-HPLC) was conducted to enrich and determine the contents of active components in the same sample solution. Before application, for HFCF-HPLC, cells growth states and survival rates on the fibre, effect of ethanol concentration in the extract of samples on cell survival rates, non-specific binding between fibre active centres and the target components, positive and negative controls and repeatabilities were validated;for HFLPME, extraction solvent, sample phase pH, agitation speed, extraction time and sample phase volume were investigated. Many active components were screened from three medicines. Some of them, such as scoparone, psoralen, bergapten, oxypeucedanin, imperatorin, ligustilide, were identified by MS. The target fishing factors of active components and the cell apoptosis rates of three cells under the medicines effect were researched. The binding sites of active groups on HepG-2 cells were preliminarily determined. The results demonstrated that HFCF-HPLC, coupled with HFLPME-HPLC, is a simple and universal approach to find bioactive components at the cellular level, determine their content and research traditional Chinese medicines (TCMs) entirety effect of multi-component and multi-target. The approach may provide us a new and good solution to clarify the material basis of anti-cancer effect and conduct personalized quality control for the components associated with efficacy in TCMs.
基金financially supported by National Water Pollution Control and Management Technology Major Projects(No.2009ZX07210-009)Scientific and Technological Developing Project of Shandong Province(No. 2009GG20001021-9)+1 种基金Open Research Fund Program of Shandong Provincial Key Laboratory of Eco-Environmental Science for Yellow River Delta(No.2009KFJJ01)Basic Foundation of Shandong Academy of Sciences and Analysis and Test center of Shandong province
文摘A novel temperature controlled ionic liquid dispersive liquid phase microextracfion （TCIL-DLPME） coupled with rapid resolution liquid chromatography-electrospray tandem mass spectrometry （RRLC-ESI-MS-MS） has been developed for the enrichment and determination of three hexabromocyclododecane diastereomers （HBCDs） in water samples. Green solvent ionic liquid （IL） was used as extraction solvent instead of toxic organic solvents. This technique also avoided the usage of dispersive solvent. Some important parameters that might affect the extraction efficiency were optimized. Under the optimum conditions, good linear relationship, sensitivity and reproducibility were obtained. All the limits of detection for the three diastereomers were 0.1 ng/ mL. The linear range was obtained in the range of 1-100 ng/mL for the total amount of three HBCD diastereomers. It was satisfactory to analyze real environmental water samples with the recoveries ranging from 77.2% to 99.3%. The main advantage of the method is toxic organic solvent-free.
基金supported by the Health Institutes of Turkey(TüSEB)(Project No.2020CV01-8946)。
文摘A rapid,accurate,and sensitive analytical method,ultrasonication-assisted spraying based fine droplet formationeliquid phase microextractionegas chromatographyemass spectrometry(UA-SFDF-LPME-GCMS),was proposed for the determination of trace amounts of hydroxychloroquine sulfate in human serum,urine,and saliva samples.To determine the best extraction strategy,several liquid and solid phase extraction methods were investigated for their efficiencies in isolation and preconcentration of hydroxychloroquine sulfate from biological matrices.The UA-SFDF-LPME method was determined to be the best extraction method as it was operationally simple and provided accurate results.Variables such as the extraction solvent,spraying number,sodium hydroxide concentration and volume,sample volume,mixing method,and mixing period were optimized for the proposed method using the onevariable-at-a-time approach.In addition,Tukey’s method based on a post hoc comparison test was employed to evaluate the significant difference between the parameters inspected.After the optimization studies,the limit of detection(LOD)and limit of quantification(LOQ)were determined to be 0.7 and 2.4 mg/kg,respectively.The sensitivity of the GC-MS system based on the LOD was enhanced approximately 440-fold when the UA-SFDF-LPME method was employed.Spiking experiments were also conducted for the human serum,urine,and saliva samples to determine the applicability and accuracy of the proposed method.Recoveries for the human serum,urine,and saliva samples were found to be in the ranges of 93.9%-101.7%,95.2%-105.0%,and 93.1%-102.3%,respectively.These results were satisfactory and indicated that the hydroxychloroquine sulfate level in the above biological samples could be analyzed using the proposed method.
基金Project supported by Department of Chemical,Petroleum and Gas Engineering,Iran University of Science&Technology(IUST)
文摘Microfluidic solvent extraction （micro SX） of gadolinium was conducted using a mono- and diester mixture （MDEHPA） as the cationic extractant. A microfluidic Y-Y channel was fabricated using CO2- laser technique in a glass microchip used as the extraction system. Compared with batch extraction, extraction kinetic is found fast, and extraction equilibrium is attained within 15 s. Stoichiometry of the extracted complex is found to be Gd（NOs）3-3MDEHPA using log-log plot method. Additionally, the operating parameters and overall volumetric mass transfer coefficient （kLα） were investigated to determine the mass transfer performance. Optimal condition of microextraction for gadolinium using response surface methodology was determined （feed solutions 31 mg/L adjusted to pH value 2.5, extractant concentration 2.9 vol% and extraction time 13.5 s）. In optimal condition, gadolinium extraction yield is obtained 95.5%. Findings of this study approve simplicity, portability, effectiveness, swiftness, and environmental friendliness microfluidic solvent extraction process and reveal that micro SX is useful in the field of extraction strategic metals present at low concentrations, which are otherwise not technically amenable or economically feasible to extract using current traditional methods.
