支撐液膜萃取及其在食品安全檢測中的應(yīng)用

劉 嘉，項(xiàng)錦欣，劉洵妤1,，趙國華1,,*

(1.西南大學(xué)食品科學(xué)學(xué)院，重慶 400715；2.重慶市農(nóng)產(chǎn)品加工技術(shù)重點(diǎn)實(shí)驗(yàn)室，重慶 400715；3.重慶理工大學(xué)化學(xué)與生物工程科學(xué)學(xué)院，重慶 400050)

支撐液膜萃取及其在食品安全檢測中的應(yīng)用

劉 嘉1,2，項(xiàng)錦欣3，劉洵妤1,3，趙國華1,3,*

(1.西南大學(xué)食品科學(xué)學(xué)院，重慶 400715；2.重慶市農(nóng)產(chǎn)品加工技術(shù)重點(diǎn)實(shí)驗(yàn)室，重慶 400715；3.重慶理工大學(xué)化學(xué)與生物工程科學(xué)學(xué)院，重慶 400050)

支撐液膜作為一種新穎的萃取技術(shù)，以其選擇性好、重現(xiàn)性好、節(jié)省有機(jī)溶劑等優(yōu)點(diǎn)，逐漸成為萃取技術(shù)研究的主要方向。本文在介紹支撐液膜的工作原理、結(jié)構(gòu)以及萃取影響因素的基礎(chǔ)上，就支撐液膜萃取技術(shù)在食品中農(nóng)藥、化學(xué)污染物、重金屬、食品添加劑及其他食品安全檢測方面的應(yīng)用和今后研究的重點(diǎn)進(jìn)行綜述，以期為食品安全控制技術(shù)研究提供有益的參考。

支撐液膜；萃取；檢測；食品

液膜萃取技術(shù)是20世紀(jì)中后期發(fā)展起來的一種高效、快速、節(jié)能的新興萃取技術(shù)。與固體膜分離技術(shù)相比，液膜萃取技術(shù)具有選擇性強(qiáng)、傳質(zhì)面積大、分離效率高等優(yōu)勢。常見的液膜分離方式主要包括乳化液膜和支撐液膜。雖然乳化液膜的分離效果也非常優(yōu)良，但因其操作復(fù)雜、液膜穩(wěn)定性不高、分離后目標(biāo)物質(zhì)的回收困難等缺陷嚴(yán)重限制了應(yīng)用。20世紀(jì)70年代，Bloch等[1]研究發(fā)展了支撐液膜，才使液膜萃取技術(shù)的應(yīng)用得到空前的發(fā)展。與乳化液膜相比，支撐液膜擁有更好的液膜穩(wěn)定性、選擇性以及富集效果。近年來，在廣泛深入研究的基礎(chǔ)上，支撐液膜分離技術(shù)在環(huán)境分析、生物制品分離、醫(yī)學(xué)以及食品安全分析中顯示出了廣闊的應(yīng)用前景。本文在論述支撐液膜分離特點(diǎn)、技術(shù)原理和操作類型的基礎(chǔ)上，詳細(xì)介紹了支撐液膜技術(shù)在食品安全分析中的應(yīng)用，以期為推動我國食品安全先進(jìn)分析技術(shù)的研究提供參考。

1 支撐液膜萃取技術(shù)的原理

支撐液膜通常選用疏水性微孔膜作為支撐體，用特定有機(jī)溶劑浸泡時(shí)，微孔膜通過毛細(xì)孔力將有機(jī)溶劑束縛在其孔內(nèi)，從而形成以固體載體支撐的有機(jī)溶劑液膜。從工作原理上看，支撐液膜分離技術(shù)實(shí)際上是由兩個(gè)液液萃取構(gòu)成的。一般將支撐液膜分離的被萃取液體相稱為供體，用于接受被萃取物質(zhì)的相稱為受體。在分離過程中，樣品液(供體)中的目標(biāo)分離物質(zhì)(B)首先通過供體與縛束在微孔中的液態(tài)有機(jī)溶劑形成的液液萃取過程轉(zhuǎn)移至有機(jī)液膜中。接著，目標(biāo)物質(zhì)再通過微孔中的液態(tài)有機(jī)溶劑與受體形成的液液萃取轉(zhuǎn)移至受體相中，從而實(shí)現(xiàn)目標(biāo)物質(zhì)的分離。圖1為利用支撐液膜萃取酸性物質(zhì)的原理圖。

圖2 含載體支撐液膜萃取示意圖(以酸性物質(zhì)為例)Fig.2 Schematic diagram of supported liquid membrane extraction

為實(shí)現(xiàn)目標(biāo)物質(zhì)從供體相轉(zhuǎn)移至液膜，再從液膜中轉(zhuǎn)入接受相，一般需要在形成有機(jī)液膜的溶劑中加入能特異性轉(zhuǎn)移目標(biāo)物質(zhì)的載體。含載體的液膜萃取的過程實(shí)際上是一個(gè)反應(yīng)萃取的過程(圖2)。為實(shí)現(xiàn)分離，首先調(diào)節(jié)供體相的pH值至3使目標(biāo)分離物質(zhì)完全轉(zhuǎn)變成分子狀態(tài)(BH)，處于分子狀態(tài)的目標(biāo)分離物質(zhì)與溶解在有機(jī)液膜(如正己基醚)中的載體三辛基氧化磷 (TOPO)在液膜內(nèi)側(cè)形成氫鍵耦合物(BH…TOPO)，進(jìn)而被轉(zhuǎn)移至液膜內(nèi)。在濃度梯度的推動下氫鍵耦合物從液膜內(nèi)側(cè)擴(kuò)散至液膜外側(cè)。而在液膜外側(cè)高pH值堿液的中和作用使耦合作用破壞，氫鍵耦合物分解，目標(biāo)萃取物被轉(zhuǎn)移至受體相，同時(shí)分子態(tài)目標(biāo)萃取物(BH)被中和成離子態(tài)(B－)。由于離子態(tài)目標(biāo)萃取物無法與TOPO形成耦合物，也就無法再回到液膜中，從而實(shí)現(xiàn)了目標(biāo)物質(zhì)的定向轉(zhuǎn)移分離。解耦合后的TOPO擴(kuò)散到液膜外側(cè)再次利用。

2 支撐液膜的結(jié)構(gòu)及萃取影響因素

2.1 支撐液膜的結(jié)構(gòu)

支撐液膜的主體結(jié)構(gòu)包括液膜及支撐體。液膜通常選取一些具有較高沸點(diǎn)及表面張力的有機(jī)溶劑，例如高級烷烴、苯、醚等。支撐體可分為兩種構(gòu)型，即平板膜和中空纖維膜。平板膜(圖3)是通過供體相在支撐液膜的一側(cè)不斷地流動或者在供體相一端添加壓力，從而加快了分析物在液膜中的傳遞。由于在兩端添加了隔板，平板膜通?？梢赃B續(xù)使用。中空纖維膜(圖4)擁有相當(dāng)高的填充比，并且單位料液體積的接觸面積也大于平板膜，萃取效率更高。

圖3 平板式支撐液膜Fig.3 Flat-type supported liquid membrane

圖4 中空纖維式支撐液膜Fig.4 Hollow-fiber-type supported liquid membrane

2.2 影響支撐液膜萃取的因素

2.2.1 溫度

支撐液膜萃取的操作溫度通常控制在室溫或者稍高(25～35℃)。升高支撐液膜萃取的操作溫度，可增加擴(kuò)散系數(shù)，從而提高對目的物質(zhì)的傳質(zhì)。液膜有機(jī)溶劑的沸點(diǎn)不高是限制操作溫度的主要因素。有研究將離子液體應(yīng)用到支撐液膜[2]，一方面由于離子液體的沸點(diǎn)較高，可以通過提高操作溫度以加快液膜對分析物的萃取速率；另一方面由于離子液體的黏度大，能有效地阻止液膜溢出，從而加強(qiáng)了支撐液膜的穩(wěn)定性。

2.2.2 有機(jī)溶劑及載體

支撐液膜中被用于形成液膜的有機(jī)溶劑要求在供體相及受體相中的溶解性小，這樣能較好地溶解分析物與載體，并且與支撐體有較好的兼容性[3]。有機(jī)溶劑的極性和對分析物的溶解能力對萃取效果的影響很大，可按一定比例混合使用多種有機(jī)溶劑[4]或選擇使用合適的載體[5]。載體一方面可以大幅度提高萃取的選擇性，另一方面能使萃取效率提高數(shù)十倍[6]。同時(shí)，為使液膜更為綠色、環(huán)保，有報(bào)道使用植物油作為液膜分離水中的苯酚[7]和染料[8]。

2.2.3 支撐體

常用于支撐液膜中支撐體的高分子材料包括聚四氟乙烯、聚丙烯、聚砜等低溶脹性及高孔隙率的疏水性材料，其厚度從幾微米到幾百微米不等。一般平板型支撐液膜的支撐體較中空纖維型更厚[9]。若需提高支撐體穩(wěn)定性可選用較小孔徑的材料，而要獲得較好的通量則需選取較大孔徑的材料。

2.2.4 其他因素

在萃取酸性物質(zhì)時(shí)，供體相中的p H值應(yīng)足夠低，以確保目的物質(zhì)質(zhì)子化后能穿過液膜。接受相的pH值則根據(jù)實(shí)驗(yàn)具體要求進(jìn)行調(diào)節(jié)，需要考慮對檢測器的干擾且是否有利于載體釋放分析物等因素。另外，對于平板模型的支撐體，適當(dāng)調(diào)整其供體相流速能有效地增加料液與膜之間的接觸時(shí)間，從而提高萃取效果[10]。

3 支撐液膜萃取技術(shù)在食品安全檢測中的應(yīng)用

作為一種優(yōu)秀的萃取分離技術(shù)，支撐液膜萃取技術(shù)以其高富集能力與高選擇性等特色已發(fā)展成為一種食品安全樣品前處理技術(shù)，可用于農(nóng)藥、化學(xué)污染物、重金屬、抗生素、食品添加劑等檢測。

3.1 農(nóng)藥檢測

研究表明利用支撐液膜進(jìn)行樣品前處理可用于包括氨基甲酸酯類、聯(lián)啶類、硝基酚類、鹵代苯氧類等農(nóng)藥的檢測(表1)。Zhu等[11]利用支撐液膜富集分離了牛奶中鹵代苯氧型除草劑，檢測結(jié)果的相對平均偏差低于7.1%，檢測在1～200ng/L范圍內(nèi)線性關(guān)系好，被檢測物的富集倍數(shù)可達(dá)700。Piriyapittaya等[12]使用溶有載體(季胺化合物-336)的正己基醚作為膜液萃取純水中草甘膦和胺甲基磷酸。目標(biāo)物的萃取效果好，其富集倍數(shù)可達(dá)853。Msagati等[13]發(fā)現(xiàn)支撐液膜對苯并咪唑進(jìn)行富集分離的回收率高于固相微萃取。此外，支撐液膜還可用于對紅酒中果汁[10]、殺蟲劑[14]、和水[15]中三嗪除草劑的富集分離。

表1 支撐液膜技術(shù)在農(nóng)藥檢測上的應(yīng)用Table 1 Application of supported liquid membrane in the inspection of pesticides

3.2 化學(xué)污染物檢測

支撐液膜可以用于水體中氯化消毒副產(chǎn)物(鹵乙酸)、多環(huán)芳烴類、氯酚類等污染物的檢測(表2)。Kou等[2]使用離子液體作為膜液富集分離水中鹵乙酸類污染物，富集倍數(shù)在300～3000之間，且萃取率高于50%。Liu等[4]以三氯甲烷作為膜液，實(shí)現(xiàn)了對水體中5種氯酚類化合物的分離。Peng等[19]發(fā)現(xiàn)以離子液體作為膜液時(shí)，重復(fù)性更好。

表2 支撐液膜技術(shù)在化學(xué)污染物檢測上的應(yīng)用Table 2 Application of supported liquid membrane in the inspection of chemical contaminants

3.3 重金屬檢測

可利用支撐液膜技術(shù)對水樣中銅、鉻、鉛等重金屬進(jìn)行富集分離(表3)。Parthasarathy等[25]在對微量銅、鉛、鉻的富集分離中，以甲苯和苯基己烷的混合溶液作為膜液，富集倍數(shù)可達(dá)1000。Peng等[26]研究了以雙硫腙作為萃取載體富集分離鉻，其富集倍數(shù)可達(dá)387。Cukrowska等[27]以四乙基硼酸鈉為載體對氯化三苯錫、氯化三叔丁基錫、三氯化叔丁基錫、二氯化二叔丁基錫等有機(jī)錫進(jìn)行富集分離，富集倍數(shù)可達(dá)1000～4000。

表3 支撐液膜技術(shù)在重金屬檢測上的應(yīng)用Table 3 Application of supported liquid membrane in the inspection of heavy metals

3.4 抗生素檢測

抗生素是當(dāng)前動物性食品重點(diǎn)的污染物，在分析監(jiān)控磺胺類、乳胺類等時(shí)可用支撐液膜對樣品進(jìn)行分離富集(表4)。Msagati等[5]利用支撐液膜富集分離了水、牛奶和牛肝腎等多種樣品中的磺胺類藥物。同時(shí)，他們還發(fā)現(xiàn)利用支撐液膜萃取分離β-乳胺類抗生素的萃取效率比固相微萃取好，可使目標(biāo)物質(zhì)的檢測限大幅度降低。Raich等[30]應(yīng)用支撐液膜富集分離雙氫除蟲菌素，其萃取效率與固相微萃取相當(dāng)，但萃取時(shí)間更短、有機(jī)溶劑使用更少。

表4 支撐液膜技術(shù)在抗生素檢測上的應(yīng)用Table 4 Application of supported liquid membrane in the inspection of antibiotics

3.5 食品添加劑檢測

Luque-Perez等[32]將支撐液膜應(yīng)用于咖啡因的富集，并設(shè)計(jì)出一套流動進(jìn)樣系統(tǒng)，實(shí)現(xiàn)了對目標(biāo)物的在線檢測。Zougagh等[33]使用十一烷與己醚作為膜液萃取分離咖啡和茶葉中的咖啡因，并把壓電晶體、分子印跡聚合物等技術(shù)應(yīng)用于檢測。結(jié)果表明，目標(biāo)物的回收率為90%～109%，分子印跡技術(shù)增強(qiáng)了分離的選擇性，而壓電晶體提高了方法的檢測限。Avila等[34]還利用支撐液膜對食品中香草醛進(jìn)行了富集。Luque等[35]將支撐液膜與安培計(jì)結(jié)合，分別對糖果、巧克力涂層餅干、巧克力3種食品中的香草醛進(jìn)行檢測，富集倍數(shù)可達(dá)700。3.6 其他方面檢測

Liu等[36]利用支撐液膜富集分離了自來水、河水、城市污水樣品中的雙酚A類激素，在萃取30min后，3種樣品的回收率在76%～116%之間。Almeda等[37]使用辛醇作為膜液富集分離了紅酒中赭曲霉毒素并結(jié)合毛細(xì)管電泳進(jìn)行檢測，提高了測定的靈敏度，并且測定的相對標(biāo)準(zhǔn)偏差在5%以內(nèi)。

4 結(jié) 語

支持液膜萃取是一種極具發(fā)展?jié)摿Φ沫h(huán)境友好型萃取技術(shù)。與傳統(tǒng)的溶劑萃取相比，它具有傳質(zhì)速度快、富集倍數(shù)高、選擇性強(qiáng)、節(jié)省樣品、節(jié)省有機(jī)溶劑等優(yōu)點(diǎn)。該技術(shù)目前被廣泛研究應(yīng)用于環(huán)境分析、生化分析、分子相互作用分析、食品安全分析等領(lǐng)域。在食品安全領(lǐng)域中，它可用于食品中農(nóng)藥、化學(xué)污染物、重金屬、食品添加劑的檢測。但目前支撐液膜的應(yīng)用主要集中在環(huán)境分析中，在食品分析中的研究仍相對偏少，還有很大發(fā)展空間。難于自動化和萃取的穩(wěn)定性是限制當(dāng)前支持液膜萃取的主要技術(shù)因素。便攜式小型支撐液膜萃取裝置、液膜穩(wěn)定技術(shù)以及支撐液膜與現(xiàn)代分析儀器偶聯(lián)技術(shù)的深度開發(fā)對支撐液膜在工業(yè)分析中大面積應(yīng)用至關(guān)重要。

[1] BLOCH R, FROMMER M A. The mechanism for formation of skinned membranes I. Structure and properties of membranes cast from binary solutions[J]. Desalination, 1970, 7(2): 259-264.

[2] KOU D, WANG X Y, MITRA S. Supported liquid membrane microextraction with high-performance liquid chromatography-UV detection for monitoring trace haloacetic acids in water[J]. Journal of Chromatography A, 2004, 1055(1/2): 63-69.

[3] KHROLENKO M V, WIECZOREK P P. Determination of glyphosate and its metabolite aminomethylphosphonic acid in fruit juices using supported-liquid membrane preconcentration method with high-performance liquid chromatography and UV detection after derivatization withp-toluenesulphonyl chloride[J]. Journal of Chromatography A, 2005, 1093(1/2): 111-117.

[4] LIU Jingfu, XIA Liang, CHI Yuguang, et al. High performance liquid chromatography determination of chlorophenols in water samples after preconcentration by continuous flow liquid membrane extraction on-line coupled with a precolumn[J]. Analytica Chimica Acta, 2003, 487(2): 129-135.

[5] MSAGATI T A M, NINDI M M. Multiresidue determination of sulfonamides in a variety of biological matrices by supported liquid membrane with high pressure liquid chromatography-electrospray mass spectrometry detection[J]. Talanta, 2004, 64(1): 87-100.

[6] LIU Jingfu, TORANG L, JONSSON J A. Passive extraction and cleanup of phenoxy acid herbicides in samples from a groundwater plume using hollow fiber supported liquid membranes[J]. Journal of Chromatography A, 2007, 1160(5): 56-63.

[7] VENKATESWARAN P, PALANIVELU K. Recovery of phenol from aqueous solution by supported liquid membrane using vegetable oils as liquid membrane[J]. Journal of Hazardous Materials B, 2006, 131(1/3): 146-152.

[8] MUTHURAMAN G, PALANIVELU K. Transport of textile dye in vegetable oils based supported liquid membrane[J]. Dyes and Pigments, 2006, 70(2): 99-104.

[9] MULUGETA M, MEGERSA N. Carrier-mediated extraction of bipyridilium herbicides across the hydrophobic liquid membrane[J]. Talanta, 2004, 64(1): 101-108.

[10] KHROLENKO M, DZYGIEL P, WIECZOREK P. Combination of supported liquid membrane and solid-phase extraction for sample pretreatment of triazine herbicides in juice prior to capillary electrophoresis determination[J]. Journal of Chromatography A, 2002, 975(1): 219-227.

[11] ZHU Lingyan, EE K H, ZHAO Limian, et al. Analysis of phenoxy herbicides in bovine milk by means of liquid-liquid-liquid microextraction with a hollow-fiber membrane[J]. Journal of Chromatography A, 2002, 963(1/2): 335-343.

[12] PIRIYAPITTAYA M, JAYANTA S, LEEPIPATPIBOON N, et al. Micro-scale membrane extraction of glyphosate and aminomethylphosphonic acid in water followed by high-performance liquid chromatography and post-column derivatization with fluorescence detector[J]. Journal of Chromatography A, 2008, 1189(1/2): 483-492.

[13] MSAGATI T A M, NINDI M M. Comparative study of sample preparation methods; supported liquid membrane and solid phase extraction in the determination of benzimidazole anthelmintics in biological matrices by liquid chromatography-electrospray-mass spectrometry[J]. Talanta, 2006, 69(1): 243-250.

[14] HYOTYLAINEN T, LUTHJE K, RAUTIAINEN R M, et al. Determination of pesticides in red wines with on-line coupled microporous membrane liquid-liquid extraction-gas chromatography[J]. Journal of Chromatography A, 2004, 1056(1/2): 267-271.

[15] BJARNI B, LUKE C, PATRIK O, et al. Enzyme flow immunoassay using a Protein G column for the screening of triazine herbicides in surface and waste water[J]. Analytica Chimica Acta, 2001, 426(2): 197-207.

[16] LAMBROPOULOU D A, ALBANIS T A. Application of hollow fiber liquid phase microextraction for the determination of insecticides in water[J]. Journal of Chromatography A, 2005, 1072(1): 55-61.

[17] SANDAHL M, MATHIASSON L, JONSSON J A. Determination of thiophanate-methyl and its metabolites at trace level in spiked natural water using the supported liquid membrane extraction and the microporous membrane liquid-liquid extraction techniques combined on-line with high-performance liquid chromatography[J]. Journal of Chromatography A, 2000, 893(1):123-131.

[18] BERHANU T, LIU J F, JONSSON J A K, et al. Determination of trace levels of dinitrophenolic compounds inenvironmental water samples using hollow fiber supported liquidmembrane extraction and high performance liquid chromatography[J]. Journal of Chromatography A, 2006, 1103(1): 1-8.

[19] PENG Jinfeng, LIU Jingfu, HU Xialin, et al. Direct determination of chlorophenols in environmental water samples by hollow fiber supported ionic liquid membrane extraction coupled with high-performance liquid chromatography[J]. Journal of Chromatography A, 2007, 1139 (2): 165-170.

[20] HSIEH Y N, HUANG P C, KUEI C H. Nafion membrane-supported ionic liquid-solid phase microextraction for analyzing ultra trace PAHs in water samples[J]. Analytica Chimica Acta, 2006, 557(2): 321-328.

[21] VORA-ADISAK N, VARANUSUPAKUL P. A simple supported liquid hollow fiber membrane microextraction for sample preparation of trihalomethanes in water samples[J]. Journal of Chromatography A, 2006, 1121(2): 236-241.

[22] WANG Xiaoyan, KOU Dawen, MITRA S. Continuous on-line monitoring of haloacetic acids via membrane extraction[J]. Journal of Chromatography A, 2005, 1089(2): 39-44.

[23] TUDORACHE M, EMNEUS J. Selective immuno-supported liquid membrane (ISLM) extraction,enrichment and analysis of 2,4,6-trichlorophenol[J]. Journal of Membrane Science, 2005, 256(1/2): 143-149.

[24] ALMEDA S, NOZAL L, VALCARCEL M. Direct determination of chlorophenols present in liquid samples by using a supported liquid membrane coupled in-line with capillary electrophoresis equipment[J]. Analytica Chimica Acta, 2007, 587(1): 97-103.

[25] PARTHASARATHY N, PELLETIER M, BUFFLE J. Hollow fiber based supported liquid membrane: a novel analytical system for trace metal analysis[J]. Analytica Chimica Acta, 1997, 350(1/2): 183-195.

[26] PENG Jinfeng, LIU Rui, LIU Jingfu, et al. Ultrasensitive determination of cadmium in seawater by hollow fiber supported liquid membrane extraction coupled with graphite furnace atomic absorption spectrometry [J]. Spectrochimica Acta Part B, 2007, 62(5): 499-503.

[27] CUKROWSKA E, CHIMUKA L, NSENGIMANA H, et al. Application of supported liquid membrane probe for extraction and preconcentration of organotin compounds from environmental water samples[J]. Analytica Chimica Acta, 2004, 523(1): 141-147.

[28] NDUNGU K, DJANE N K, MATHIASSON L. Determination of trace metal ions by ion-pair chromatography after enrichment using supported liquid membrane[J]. Journal of Chromatography A, 1998, 826(1): 103-108.

[29] DJANE N K, NDUNGU K, MATHIASSON L, et al. Chromium speciation in natural waters using serially connected supported liquid membranes [J]. Talanta, 1999, 48(5): 1121-1132.

[30] RAICH M J, KROGH K A, GRANADOS M, et al. Determination of ivermectin and transformation products in environmental waters using hollow fibre-supported liquid membrane extraction and liquid chromatography-mass spectrometry/mass spectrometry[J]. Journal of Chromatography A, 2008, 1187(1/2): 275-280.

[31] MSAGATI T A M, NINDI M M. Determination ofβ-lactam residues in foodstuffs of animal origin using supported liquid membrane extraction and liquid chromatography-mass spectrometry[J]. Food Chemistry, 2007, 100(2): 836-844.

[32] LUQUE-PEREZ E, RIOS A, VALCARCEL M, et al. Spectrophotometric flow injection determination of caffeine in solid and slurry coffee and tea samples using supported liquid membranes[J]. Laboratory Automation and Information Management, 1999, 34(2): 131-142.

[33] ZOUGAGH M, RIOS A, VALCARCEL M. Automatic selective determination of caffeine in coffee and tea samples by using a supported liquid membrane-modified piezoelectric flow sensor with molecularly imprinted polymer[J]. Analytica Chimica Acta, 2005, 539(1/2): 117-124.

[34] AVILA M, ZOUGAGH M, RIOS A, et al. Supported liquid membranemodified piezoelectric flow sensor with molecularly imprinted polymer for the determination of vanillin in food samples[J]. Talanta, 2007, 72 (4): 1362-1369.

[35] LUQUE M, LUQUE-PEREZ E, VALCARCEL M, et al. Supported liquid membranes for the determination of vanillin in food samples with amperometric detection[J]. Analytica Chimica Acta, 2000, 410(1/2): 127-134.

[36] LIU Jingfu, XIA Liang, JIANG Guibin, et al. Evaluation of an on-line coupled continuous flow liquid membrane extraction and precolumn system as trace enrichment technique by liquid chromatographic determination of bisphenol A[J]. Talanta, 2003, 60(6): 1155-1161.

[37] ALMEDA S, ARCE L, VALCARCEL M. Combined use of supported liquid membrane and solid-phase extraction to enhance selectivity and sensitivity in capillary electrophoresis for the determination of ochratoxin A in wine[J]. Electrophoresis, 2008, 29(7): 1573-1581.

Supported Liquid Membrane Extraction and Its Application in Food Safety Inspection

LIU Jia1,2，XIANG Jin-xin3，LIU Xun-yu1,3，ZHAO Guo-hua1,3,*
(1. College of Food Science, Southwest University, Chongqing 400715, China；2. Chongqing Key Laboratory of Agricultural Product Processing, Chongqing 400715, China；3. College of Chemical and Bioengineering, Chongqing Technology University, Chongqing 400050, China)

Supported liquid membrane extraction, a novel extract technique with advantages of economic organic solvents, high selectivity and good reproducibility has been attracted extensive attention. In this paper, working principle, structure and factors of this extraction technique were introduced and its applications in the detection of pesticides, chemical pollutants, heavy metals, and other toxic substances in food was discussed, which will provide valuable references for food safety control and inspection.

supported liquid membrane；extraction；inspection；food

TS201.21

A

1002-6630(2010)13-0321-05

2009-12-03

重慶市自然科學(xué)基金項(xiàng)目(CSTC 2007BB1393)

劉嘉(1985—)，男，碩士研究生，研究方向?yàn)槭称坊瘜W(xué)。E-mail：mcgrady456@163.com

*通信作者：趙國華(1971—)，男，教授，博士，研究方向?yàn)槭称坊瘜W(xué)。E-mail：zhaoguohua1971@163.com