Combination of hollow fiber-based liquid-phase microextraction with sweeping techniques in micellar electrokinetic chromatography for the determination of Strychnos alkaloids in human urine

A new method for the enrichment of Strychnos alkaloids in biological samples via liquid-phase microextxaodon （LPME） based on porous polypropylene hollow fibers in combination with on-line sweeping in micellar electrokinodc chromatography was developed. The calibration curve was linear over the range of 20-200 ng mL^-1 for both strychnine and brucine in human urine sample. The detection limits （S/N = 3：1） for strychnine and brucine were 1 ng mL^-1 and 2 ng mL^-1, respectively. The LPME-sweeping method has been successfully applied to the analysis of strychnine and brucine in real urine samples.

Trace Determination of Tamoxifen in Biological Fluids Using Hollow Fiber Liquid-Phase Microextraction Followed by High-Performance Liquid Chromatography-Ultraviolet Detection

The applicability of hollow fiber liquid-phase microextraction (HF-LPME) combined with high-performance liquid chromatography-ultraviolet detection (HPLC-UV) was evaluated for the extraction and determination of tamoxifen (TAM) in biological fluids including human urine and plasma. The drug was extracted from a 15 mL aqueous sample (source phase;SP) into an organic phase impregnated in the pores of the hollow fiber (membrane phase;MP) followed by the back-extraction into a second aqueous solution (receiving phase;RP) located in the lumen of the hollow fiber. The effects of several factors such as the nature of organic solvent, compositions of SP and RP solutions, extraction time, ionic strength and stirring rate on the extraction efficiency were examined and optimized. An enrichment factor of 360 along with substantial sample clean up was obtained under the optimized conditions. The calibration curve showed linearity in the range of 1 - 500 ng?mL–1 and the limit of detection was found to be 0.5 ng?mL–1 in aqueous medium. A reasonable relative recovery (≥89%) and satisfactory intra-assay (3.7% - 4.2%, n = 3) and inter-assay (7.5% - 7.8%, n = 3) precision illustrated good performance of the analytical procedure in spiked human urine and plasma samples.

Extraction and Determination of Three Chlorophenols by Hollow Fiber Liquid Phase Microextraction - Spectrophotometric Analysis, and Evaluation Procedures Using Mean Centering of Ratio Spectra Method

A method termed hollow fiber liquid phase microextraction (HF-LPME) was utilized to extract three chlo- rophenols, 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP) and 2,4,6- trichlorophenol (2,4,6-TCP), separately from water. The extracted chlorophenols were then separated, identified, and quantified by UV-Vis spectrophotometry with photodiode array detection (UV-Vis/DAD). In the study, experimental con-ditions such as organic phase identity, acceptor phase volume, sample agitation, extraction time, acceptor phase NaOH concentration, donor phase HCl concentration, salt addition, and UV absorption wavelength were optimized. The statistical parameters of the proposed method were investigated under the selected con-ditions. The analytical characteristics of the method such as detection limit, accuracy, precision, relative standard deviation (R.S.D.) and relative standard error (R.S.E.) was calculated. The results showed that the proposed method is simple, rapid, accurate and precise for the analysis of ternary mixtures.

HS-LPME-GC法在烟用香精香料质量控制中的应用

采用顶空液相微萃取法(HS-LPME)对8个不同批次及掺兑不同比例其他烟用香精香料的1148#样品的挥发性成分进行提取并用气相色谱法分析,同时研究了不同萃取溶剂、萃取时间、萃取温度对分析结果的影响,确定了最佳条件:样品在70℃下平衡1.0h,搅拌速度300r/min,以4.0μL正十二烷作萃取剂,萃取时间为10min,并通过主成分分析(PCA)法对不同批次及掺兑样品进行模式识别。结果表明:此法能成功地将掺兑样品区分开来,可以成为烟用香精香料1148#质量控制的有效手段之一。

Combination of dynamic hollow fiber liquid-phase microextraction with HPLC analysis for the determination of UV filters in cosmetic products

A simple method based on hollow fiber liquid-phase microextraction (HF-LPME) followed by high performance liquid chro-matography (HPLC) analysis was successfully developed for the determination of UV filters in cosmetic products. A canular extractor was assembled by mounting a hollow fiber inside an external tube with a tee-connector. The organic solvent was immobilized into the fiber to form a liquid membrane as the acceptor phase. The sample was continuously injected into the extractor and the UV filters were extracted from the aqueous sample into organic acceptor phase. The main parameters affecting HF-LPME including extraction solvent, sample volume, sample flow rate, pH values and ionic strength were investigated. Toluene has been verified to be suitable as the acceptor phase. Under the optimized HF-LPME conditions, the enrichment factors of five UV filters varying from 24 to 57 were achieved. The limits of detection for the five UV filters were in the range of 1-100 μg L-1 .The relative standard deviations (RSDs) of HF-LPME and HPLC analysis were lower than 5.2%. The proposed method has been successfully applied to the analysis of the varied cosmetic products.

Combination of ionic liquid dispersive liquid-phase microextraction and high performance liquid chromatography for the determination of triazine herbicides in water samples

A temperature-controlled ionic liquid dispersive liquid-phase microextraction in combination with high performance liquid chromatography was developed for the enrichment and determination of triazine herbicides such as cyanazine,simazine,and atrazine in water samples.1-Octyl-3-methylimidazolium hexafluorophosphate（[C8MIM][PF6]） was selected as the extraction solvent.Several experimental parameters were optimized.Under the optimal conditions,the linear range for cyanazine was in the concentration range of 0.5–80 mg/L and the linear range for simazine and atrazine was in the range of1.0–100 mg/L.The limit of detection（LOD,S/N = 3） was in the ranges of 0.05–0.06 mg/L,and the intra day and inter day precision（RSDs,n = 6） was in the ranges of 3.2%–6.6% and 4.8%–8.9%,respectively.Four real water samples were analyzed with the developed method,and the experimental results showed that the spiked recoveries were satisfactory.All these exhibited that the developed method was a valuable tool for monitoring such pollutants.

三相中空纤维-液相微萃取-高效液相色谱法快速测定烟用香精中9种防腐剂

烟用香精不仅可应用于传统卷烟,其在电子烟、加热卷烟及口含烟等新型烟草制品中均有着广泛应用。烟用香精的含水量较高,为避免香精产品在生产、储存和运输环节发生霉变,往往加入一定量的防腐剂(如山梨酸、苯甲酸及对羟基苯甲酸酯类化合物),以抑制细菌的生长。然而,若超标添加上述防腐剂,亦会对消费者健康带来不良影响。本研究基于三相中空纤维-液相微萃取(3P-HF-LPME)-高效液相色谱法,建立了一种同时测定烟用香精中山梨酸、苯甲酸及7种对羟基苯甲酸酯类防腐剂的分析方法。对仪器参数和HF-LPME条件进行优化,采用Agilent Poroshell 120 EC-C18色谱柱(100 mm×3 mm,2.7μm)对9种防腐剂进行分离,以甲醇、0.02 mol/L乙酸铵水溶液(含0.5%乙酸)和乙腈作为流动相进行梯度洗脱,检测波长为226 nm(苯甲酸)和258 nm(山梨酸和7种对羟基苯甲酸酯类化合物)。以二己醚为萃取溶剂,15 mL样品溶液(pH 4)为样品相,氢氧化钠水溶液(pH 12)为接受相,在800 r/min下搅拌萃取30 min。实验结果表明,9种目标分析物在各自的线性范围内线性关系良好,相关系数(r)≥0.9967,检出限为0.02~0.07 mg/kg,定量限为0.08~0.24 mg/kg,富集倍数为30.6~91.1,在3个加标水平下的回收率为82.2%~115.7%,相对标准偏差(n=5)≤15.0%。该方法简单高效,准确可靠,灵敏度高,适用于烟用香精中防腐剂的快速筛查。

微萃取技术在环境分析中的应用

微萃取技术是近年来出现的绿色样品前处理技术。它具有操作简便、环境友好等优点,并且在环境、医药及食品等领域得到广泛的应用。本文仅就固相微萃取和液相微萃取在环境分析中的应用作一简要综述。

液相微萃取-高效液相色谱联用分析化妆品中痕量的雌激素

建立了液相微萃取-高效液相色谱联用(LPME-HPLC)测定爽肤水中痕量的雌三醇、雌二醇、炔雌醇和雌酮的分析方法,研究了萃取溶剂种类、接受相体积、搅拌速度、萃取时间等对萃取效率的影响。结果表明,该方法对4种雌激素的富集倍数可达到247-343倍,方法的线性范围为1-200μg/L,检出限为0.4-1.0μg/L,6次平行测定的相对标准偏差为3.6%-7.3%,爽肤水中的加标回收率为101.2%-114.9%。方法简单快速、灵敏度高、环境友好,满足痕量雌激素分析的要求。

超高效液相色谱-串联质谱法同时测定尿样中4种痕量的乌头类生物碱

建立了超高效液相色谱-串联质谱(UPLC-MS/MS)结合中空纤维微萃取(HF-LPME)同时检测尿样中痕量的乌头碱、次乌头碱、新乌头碱和滇乌头碱等4种生物碱的方法。采用HF-LPME对尿样进行提取、纯化和富集,富集倍数达102～301。同时采用电喷雾电离(ESI)、多反应监测(MRM)进行含量测定,显著提高了尿液中乌头类生物碱的检测灵敏度,4种乌头类生物碱的定量限达到0.01～0.1 ng/L,可大大延长中毒患者尿样中乌头类生物碱的检测时间窗。方法验证结果表明,尿液中乌头碱、新乌头碱和滇乌头碱在0.01～10 ng/L、次乌头碱在0.1～100 ng/L范围内线性关系良好,提取回收率为80.2%～109%,相对标准偏差小于4.6%。该方法适用于乌头类生物碱中毒案件的检测,为痕量乌头类生物碱分析提供了灵敏的分析方法。

液相微萃取/高效液相色谱法测定环境水样中的痕量苯脲类除草剂

建立了液相微萃取/高效液相色谱联用（LPME/HPLC）技术同时测定环境水中痕量异丙隆、秀谷隆和灭草隆除草剂的分析方法。考察了不同萃取条件及测定条件对检测结果的影响。优化后的萃取条件为：6μL正辛醇作萃取剂,液滴体积3μL,搅拌速度450 r/min,萃取30 min。结果表明,在优化条件下,3种除草剂的质量浓度在0.5~800μg/L范围内与其峰面积呈良好线性,相关系数为0.995 8~0.998 3,异丙隆、秀谷隆和灭草隆的富集倍数分别为510、490和350倍,检出限分别为0.2、0.2、0.4μg/L,加标回收率为62%~92%,相对标准偏差（RSD）为4.3%~7.7%。该法灵敏度高、操作简单、快速,能满足环境水样中痕量苯脲类除草剂残留的分析要求。

中空纤维膜液相微萃取技术/气相色谱-质谱法对食品中防腐剂与抗氧化剂的测定

将中空纤维膜液相微萃取技术与气相色谱-离子阱质谱联用,测定食品中的4种防腐剂(对羟基苯甲酸甲酯(MP)、对羟基苯甲酸乙酯(EP)、对羟基苯甲酸丙酯(PP)及对羟基苯甲酸丁酯(BP))和3种抗氧化剂(叔丁基-4-羟基苯甲醚(BHA)、叔丁基苯二酸(TBHQ)、2,6-二叔丁基对甲酚(BHT))。优化的萃取条件:以15%(质量分数)Na2SO4的盐溶液为稀释溶剂,5μL甲苯为萃取溶剂,搅拌速率为1200r/min,萃取时间为15min。该方法的线性范围为0.4～80mg/kg,检出限为0.002～8.0μg/kg,加标回收率为94%～115%,相对标准偏差为4.38%～9.34%。

微波辅助-顶空液相微萃取在线联用-高效液相色谱法测定环境水样中的敌敌畏

基于微波辅助-顶空液相微萃取联用(MAE-HS-LPME)这一样品前处理方法,采用高效液相色谱法(HPLC)对水样中的敌敌畏残留量进行了测定。对影响萃取的因素如萃取剂、微波辐射功率、萃取时间、离子强度和样品基质的pH值等进行了考察。萃取条件为:选用二甲苯作萃取剂,萃取时间为15min,微波辐射功率300W,NaCl含量为5%,pH为2.5。在最佳条件下,敌敌畏的检出限(信噪比为3时)为0.96μg/L,定量限(信噪比为10时)为3.20μg/L,萃取富集倍数为54,实际水样的加标回收率为87.4%～103%。与传统的前处理方法相比,本方法具有简便、快速、高效、节省溶剂、选择性好、应用范围广的特点。

中空纤维液相微萃取-超高效液相色谱-串联质谱法测定儿童玩具中6种致敏香豆素类化合物

建立了超高效液相色谱-串联质谱测定儿童玩具中6种致敏香豆素类化合物(香豆素、7-甲基香豆素、7-甲氧基香豆素、7-乙氧基-4-甲基香豆素、4,6-二甲基-8-叔丁基香豆素和六氢香豆素)的分析方法。样品前处理采用中空纤维液相微萃取技术,优化后的萃取实验条件为:萃取剂正辛醇,搅拌速度700 r/min,萃取时间50 min,氯化钠加入量0.7 g。萃取液经ACQUITY UPLC BEH Phenyl色谱柱(150 mm×2.1 mm,1.7μm)分离,目标化合物在电喷雾离子源正离子模式下电离,采用多反应监测模式进行定性定量分析。结果表明,6种致敏香豆素类化合物的定量限为2μg/kg(7-乙氧基-4-甲基香豆素、4,6-二甲基-8-叔丁基香豆素)或10μg/kg(香豆素、六氢香豆素、7-甲基香豆素、7-甲氧基香豆素),在10~120μg/kg范围内不同加标水平下的平均回收率为70.8%~118.9%,相对标准偏差为0.19%~16.34%(n=6)。该法准确、灵敏、可靠,适用于玩具产品的实际检验工作和产品质量控制。

止咳糖浆中磷酸可待因含量的测定

目的:为控制复方可待因药品的质量和非治疗性使用,建立磷酸可待因含量的测定方法。方法:采用气相色谱法(GC)/中空纤维膜-液相微萃取(liquid phase microextraction supposed by hollow fiber membrane,LPME-HFM)测定止咳糖浆中磷酸可待因的含量。结果:磷酸可待因浓度在1.0～50.0μg·mL^(-1)间有良好的线性关系,平均回收率为102.7%,RSD为4.2%。结论:方法简单、快速、微量,灵敏度高,可用于控制药品质量和监管复方可待因止咳药水的滥用。

液相微萃取在法庭科学中的研究进展

液相微萃取集采样、萃取、富集于一体,具有成本低,溶剂用量少,易与高效液相色谱、气相色谱、毛细管电泳、质谱等多种分析仪器联用等特点。而且回收率和富集效率都较高,样品的净化功能强大,特别适用于物证检材中痕量、超痕量目标分析物的提取。本文对液相微萃取原理、装置和操作模式以及近年来在物证分析中的研究进展进行了综述。

顶空液相微萃取/气相色谱-质谱对中药枳壳中有机挥发物的快速分析

建立了顶空液相微萃取/气相色谱-质谱联用测定中药枳壳中有机挥发物的方法。在顶空液相微萃取实验条件优化的基础上,确定了最佳实验条件:以正辛烷作为有机萃取剂,体积为2μL,样品用量为0.3g,液滴距离样品表面0.8 cm处,萃取8 m in后直接进样。与固相微萃取/气相色谱-质谱法相比,顶空液相微萃取法定性了30种成分,固相微萃取法定性了24种成分,顶空液相微萃取法操作简单、快速,实验结果灵敏度更高,且萃取效率高,重复性好,可用于中药枳壳中有机挥发物的快速分析。

中空纤维液相微萃取技术及其在食品有机污染物检测中的应用

中空纤维液相微萃取作为一种环境友好的新型样品前处理技术,集萃取、净化、浓缩为一体,具有装置简单,成本低,易于与多种仪器联用,富集倍数、检测限低等特点。中空纤维液相微萃取技术在国内的应用还较少。本文综述了中空纤维液相微萃取的装置、模式、原理及在食品有机污染物检测中的应用。

中空纤维膜液相微萃取及常规分析用于气相色谱-质谱分析白酒中的正己酸乙酯的比较研究

应用中空纤维膜液相微萃取技术（HF-LPME），及常规分析法与气相色谱一质谱（GC-MS）联用分别测定了3种浓香型白酒中的正己酸乙酯。两种方法都采用内标法定量，内标物为乙酸正戊酯。中空纤维膜液相微萃取的优化条件为：萃取溶剂为4．0扯L正己烷，搅拌速度为1000r／min，萃取时间为20min。中空纤维膜液相微萃取法及常规前处理分析法的线性范围分剐为25～400mg／L、5．0～500mg／L，检出限分别为0．25mg／L、0．03mg／L，加标回收率分别为83．7％～1189／6、78．4％～94．2％，相对标准偏差分别为9．4％～15．6％、3．5％～4．9％。

悬浮固化液相微萃取-高效液相色谱联用测定水样中甲硝唑和氯霉素

建立了悬浮固化液相微萃取-高效液相色谱法同时测定水样中甲硝唑和氯霉素的分析方法。采用正交实验设计对萃取多因素进行考查,如萃取剂的种类及用量、萃取温度、NaCl浓度、pH值和搅拌速度等进行优化,在最佳萃取条件下,甲硝唑和氯霉素浓度在10～400μg/mL范围内具有良好线形关系,线形相关系数分别为0.995和0.997,检出限分别为0.48μg/mL和0.98μg/mL(S/N=3),加标回收率在79.5～82.9%。方法简便、准确、专属性强,可用于测定水样中甲硝唑和氯霉素。