Hollow fiber-based liquid phase microextraction followed by analytical instrumental techniques for quantitative analysis of heavy metal ions and pharmaceuticals

Hollow-fiber liquid-phase microextraction(HF-LPME)and electromembrane extraction(EME)are miniaturized extraction techniques,and have been coupled with various analytical instruments for trace analysis of heavy metals,drugs and other organic compounds,in recent years.HF-LPME and EME provide high selectivity,efficient sample cleanup and enrichment,and reduce the consumption of organic sol-vents to a few micro-liters per sample.HF-LPME and EME are compatible with different analytical in-struments for chromatography,electrophoresis,atomic spectroscopy,mass spectrometry,and electrochemical detection.HF-LPME and EME have gained significant popularity during the recent years.This review focuses on hollow fiber based techniques(especially HF-LPME and EME)of heavy metals and pharmaceuticals(published 2017 to May 2019),and their combinations with atomic spectroscopy,UV-VIS spectrophotometry,high performance liquid chromatography,gas chromatography,capillary elec-trophoresis,and voltammetry.

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.

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.

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.

Research of Anti-Cancer Components in Traditional Chinese Medicine on Hollow Fibre Cell Fishing and Hollow Fibre Liquid Phase Microextraction

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.

Hollow Fiber Supported Liquid Membrane for Separation and Recovery of ^152+154Eu and ⁹⁰Sr from Aqueous Acidic Wastes

Separation and recovery of 152+154Eu and 90Sr from radioactive waste using tracer concentration from active material from waste tank in the ET-RR1 Egypt via hollow fiber supported liquid membrane (HFSLM) were achieved. The Polypropylene was used as supporter to carrier 0.5M Cyanex301/kerosene (bis(2,4,4-trimethylpentyl)dithiophosphinic acid and 0.1MEDTA as stripping of 152+154Eu and 90Sr ions from nitrate medium at pH ~3.6. The separation factor was found to be ~4 for 152+154Eu over 90Sr. The aqueous feed of mass transfer coefficient (ki) and the organic mass transfer coefficient (km) were calculated to be (1.52 and 4.5) × 10﹣2cm/s, respectively. In addition, the mass transfer modeling was performed and the validity of the developed model from experimental data was found to join in well with the theoretical values when the Cyanex301 concentration is higher than 1% (v/v). The number of cycles evaluated for complete separation of 152+154Eu and 90Sr is five cycles.

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.

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。

中空纤维液相微萃取-气相色谱-质谱联用法测定纺织品中的芳香胺

本文结合中空纤维液相微萃取(HF-LPME)与气相色谱-质谱(GC-MS)联用技术,建立了纺织品中邻氨基苯甲醚、2-甲氧基-5-甲基苯胺、2-萘胺、4-氨基联苯、3,3’-二氯联苯胺5种芳香胺类物质的分析方法。优化后的液相微萃取条件:样品溶液pH调节为12,以甲苯为萃取溶剂,在室温及300 rpm搅拌速度下,萃取30min。富集倍数最高能达185倍。方法的检测线性范围0.05~10μg·mL^(-1),检出限均低于10 ng·mL^(-1),精密度(RSD,n=6)为3.8~7.9%,回收率为84.0~119.8%。

中空纤维—固相微萃取—高效气相色谱法测定地表水多种苯系物

采用高孔隙率丙烯中空纤维,通过溶胶—凝胶技术将δ-Al_(2)O_(3)-SiO_(2)吸附剂沉积在中空纤维表面,制备得δ-Al_(2)O_(3)-SiO_(2)-HF固相微萃取纤维。建立中空纤维—固相微萃取—高效气相色谱(SPME-GC)法,用于定量分析地表水中苯系物含量。经预处理条件优化得到最优萃取温度55℃、时间20 min,8种苯系物在0.1~50.0μg/L浓度范围内线性良好(R2>0.993),方法检出限0.144~2.253 ng/L,相对标准偏差2.53%~9.62%,加标回收率90.1%~108.9%。经实际样品应用,该方法操作简便,灵敏度较高,精密度及准确度可满足分析需求,具有一定的推广应用价值。

三相中空纤维液相微萃取-高效液相色谱法测定铁皮石斛和金线莲中3种植物生长调节剂

在铁皮石斛和金线莲药材的人工培育过程中通常需要使用各种植物生长调节剂(PGRs),然而使用过量的PGRs不仅会影响药材的品质和疗效,而且会引发一系列的安全性问题,因此建立精准分析测定药材中残留的痕量PGRs技术方法具有重要意义。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铁皮石斛和金线莲药材中吲哚乙酸、吲哚丁酸、萘乙酸3种PGRs的分析方法。首先通过参数优化确定最佳色谱条件,然后采用超声+低温静置的提取手段制备样本溶液,优化影响3P-HF-LPME萃取效果的各个参数。确定的最佳前处理过程如下:以正辛醇作为中间相(萃取剂), pH 11.0的氢氧化钠溶液作为内相,稀盐酸调节外相溶液pH值为3.0,并在外相溶液中添加质量浓度为150 g/L的氯化钠溶液,在温度为40℃、搅拌速度为1 600 r/min条件下萃取2.0 h。3种PGRs采用Welch Ultimate XB-C_(18)色谱柱(250 mm×4.6 mm, 5μm)进行分离,以乙酸水溶液-甲醇(45∶55, v/v)为流动相进行等度洗脱。实验结果表明,在优化的条件下,所测定的3种PGRs在0.5~100.0μg/L范围内线性关系良好(决定系数(r^(2))=0.999 9),检出限(LOD)为0.02~0.15μg/L,加标回收率为88.5%~102.2%,相对标准偏差(RSD)≤3.7%(n=3)。该方法对铁皮石斛和金线莲药材中3种PGRs的萃取效率为42.0%~86.8%,富集倍数为140~289。该方法灵敏、准确、可靠、环保,且富集倍数高,适用于铁皮石斛和金线莲药材中残留的微量酸性PGRs的检测。

氮掺杂碳纳米管增强中空纤维液相微萃取-高效液相色谱法测定生物样本中溴系阻燃剂

该文建立了氮掺杂碳纳米管(N-CNTs)增强中空纤维液相微萃取(HF-LPME)结合高效液相色谱(HPLC)同时检测生物样品中四溴双酚A(TBBPA)和十溴二苯醚(BDE209)的分析方法。分别以15μL甲苯-正辛醇(1∶1,体积比)和甲苯-乙酸乙酯(1∶1,体积比)有机溶剂对血清和尿样在常温下萃取10 min,在萃取过程中,中空纤维膜排阻样品中蛋白质,避免了大分子物质的干扰。目标化合物经Kjnetex EVO C_(18)(2.1 mm×150 mm,5μm)色谱柱分离,以水和乙腈为流动相进行梯度洗脱。考察了不同萃取溶剂、提取时间、氮掺杂碳纳米管用量、样品pH值、搅拌速率、NaCl浓度和解吸溶剂种类对目标化合物萃取效率的影响。结果表明,在最佳条件下,TBBPA和BDE209分别在2~200 ng/mL和10~200 ng/mL范围内具有良好的线性关系,相关系数(r^(2))不小于0.995,检出限分别为0.375 ng/mL和2.8 ng/mL,定量下限分别为9.4 ng/mL和1.25 ng/mL。在3个加标水平下,目标分析物的回收率为84.5%~114%,相对标准偏差为1.4%~7.5%。该方法在富集TBBPA和BDE209的同时可去除生物样品中的蛋白质,方法简单、快速、灵敏度高、重复性好、绿色环保,适用于复杂基质中TBBPA和BDE209的检测。

Separation of Trivalent Samarium through Facilitated Stripping Dispersion Hollow Fiber Liquid Membrane Using p204 as Mobile Carrier

The separation of Sm（III） through stripping dispersion hollow fiber liquid membrane system （SDHFLM） containing feed phase adding acetate buffer solution and dispersion solution with HC1 solution as the stripping solution and membrane solution of di（2-ethylhexyl） phosphoric acid （p204） dissolved in kerosene, has been studied. A set of factors were studied, including pH value, initial concentration of Sm（III） and different ionic strength of feed phase, volume ratio of membrane solution and stripping solution （O/W）, HC1 concentration, carrier concentration, different stripping agents of dispersion phase on Sm（III） separation. Experimental results indicate that the optimum separa- tion conditions of Sm（III） were obtained as that HC1 concentration was 4.00 tool/L, p204 concentration was 0.150 mol/L, and volume ratio of membrane solution and stripping solution （O/W） was 1.00 in the dispersion phase, and pH value was 4.60 in the feed phase. Ionic strength had no obvious effect on separation of Sm（III）. When initial Sm（III） concentration was 1.00 × 10^-4 mol/L, the separation rate of Sm（III） was up to 93.5% in 85 min. The kinetic equation was developed in terms of the law of mass diffusion and the theory of interface chemistry. The modeled results were in good agreement with the experiment data.

Stripping dispersion hollow fiber liquid membrane containing carrier PC-88A and HNO_3 for the extraction of Sm^(3+)

Stripping dispersion hollow fiber liquid membrane system（SDHFLM） containing feed phase adding acetate buffer solution and dispersion solution with HNO_3 solution as the stripping solution and membrane solution of 2-ethyl hexyl phosphoric acid-mono-2-ethylhexyl ester（PC-88A） dissolved in kerosene,has been studied for the extraction of Sm^（3＋）.Many factors including pH value, volume ratio of membrane solution to stripping solution（OAV） and carrier concentration on Sm^（3＋） extraction were investigated. Experimental results indicate that the optimum extraction conditions of Sm^（3＋） were obtained as that PC-88A concentration was 0.120 mol/L,and OAV was 1.00 in the dispersion phase,and pH value was 4.80 in the feed phase.When initial Sm^（3＋） concentration was 1.20×10^（-4） mol/L,the extraction percentage of Sm^（3＋） was up to 92.8%in 160 min.

基于中空纤维的液相微萃取技术的研究进展

基于中空纤维的液相微萃取集采样、萃取、浓缩于一体,具有成本低,溶剂用量少,易与高效液相色谱、气相色谱、毛细管电泳联用等特点。该技术不仅可实现较高的回收率和富集效率,而且具有突出的样品净化功能,是一种环境友好的样品前处理新技术。该文对基于中空纤维的液相微萃取的装置、操作模式、基本原理及近年来应用研究的进展进行了综述。

中空纤维液相微萃取-高效液相色谱法测定水中残留的氨基甲酸酯类农药

应用中空纤维液相微萃取（HP—LPME）技术建立了水样中呋喃丹、西维因、异丙威和乙霉威的高效液相色谱分析方法。对影响HP—LPME的实验条件进行了优化。采用Accurel Q3／2聚丙烯中空纤维，以甲苯为萃取溶剂，于室温、搅拌速度为720r／min条件下在4．5mL样品溶液中萃取20min，萃取物在室温下经氮气流吹于后用流动相溶解进样。采用Baseline C18分离柱（4．6mm×250mm，5．0um），以甲醇-水（体积比为60：40）为流动相，流速为1．0mL／min。呋喃丹、西维因、异丙威和乙霉威的检测波长分别为200，223，200和208nm。该方法对4种氨基甲酸酯类农药的富集倍数均大于45倍；4种氨基甲酸酯类农药在10～100ug／L质量浓度范围内，其质量浓度与峰面积之间有良好的线性关系，相关系数均大于0．99；呋喃丹、西维因、异丙威和乙霉威的检出限（S/N=3）分别为5，1，5和3ug／L；实际水样中的加标回收率为82．0％～102．2％，相对标准偏差为2．0％～6．2％（n=6）。

三相中空纤维膜液相微萃取-高效液相色谱法测定水中痕量双酚A

建立了三相中空纤维膜液相微萃取-高效液相色谱(HF-LPME-HPLC)方法,用于分析测定水中痕量双酚A的含量。设计了三相中空纤维膜液相微萃取系统,优化的HP-LPME最佳萃取条件为:萃取剂为正辛醇,接受相NaOH浓度为0.09mol/L,样品溶液pH=4.0,NaCl加入量为30g/L,搅拌速度为900r/min,萃取时间为60min。萃取后取20!L接受相进行色谱分析。在最佳萃取条件下,方法的线性范围为0.5～200!g/L(r>0.999),检出限(信噪比为3)为0.2!g/L;富集因子为241;方法RSD<3.2%(n=3)。在实际环境水样中添加5,20和50!g/L的双酚A标准物质,加标平均回收率为92.8%～101.9%。表明本方法可用于水中痕量双酚A的快速准确测定。

复杂基质中柠檬酸的液相微萃取

建立了一种利用液相微萃取技术进行样品前处理、高效液相色谱进行测定的复杂基质中柠檬酸分析的简便方法。研究表明,该样品前处理方法集萃取、富集、净化为一步,具有快速、有效、绿色的特点;测定方法的线性范围为0.7~600μg/mL,相关系数为0.999 5,检测限为0.27μg/mL（S/N=3）,相对标准偏差小于5%。

中空纤维三相液相微萃取-高效液相色谱法测定水中的4种酚类化合物

建立了中空纤维液-液-液三相微萃取-高效液相色谱法测定水中4种酚类化合物的方法。实验系统地优化了影响萃取效率的因素（包括有机溶剂种类、接收相浓度、分散相pH值、加盐量、转速及萃取时间）。得到的最佳萃取条件为：萃取剂为正辛醇,接收相NaOH溶液的浓度为0.09mol/L,分散相的pH为4,萃取时间为40min,搅拌速度为600r/min,NaCl加入量达到100g/L。在最佳萃取条件下,该方法对苯酚、4-甲酚、2,4-二甲酚和2-萘酚的检出限（信噪比为3）分别为0.4、0.4、1.2和0.4μg/L,富集因子分别为111.6、129.5、71.0和175.6。在实际环境样品中添加5、50μg/L水平的4种酚类化合物,其加标回收率为85.9%-119.0%。研究结果表明该方法简便、快速、准确,可用于水环境中酚类化合物的测定。

中空纤维膜液相微萃取-气相色谱质谱法快速测定蔬菜汁中15种邻苯二甲酸酯

采用中空纤维膜-液相微萃取结合GC-MS检测蔬菜汁中15种邻苯二甲酸酯。对萃取溶剂、振荡速度、振荡时间进行了优化:在萃取温度为23℃(室温)、搅拌速度为快速、萃取时间为50min的条件下正己烷萃取效果较好;采用DB-5MS石英毛细管柱(30 m×0.25 mm×0.25μm)、气相色谱质谱(EI)进行分离检测。15种邻苯二甲酸酯在此方法条件下的富集倍数在4.2～315.6之间;检出限在0.0001～0.01 mg/L之间。当添加浓度范围在0.05～1 mg/kg时,回收率在71.8%～90.1%之间,RSD为2.1%～18.9%。本方法可用于蔬菜汁中邻苯二甲酸酯的测定。