分子印迹固相萃取技术及其在环境中多环芳烃测定中的应用进展

熊满艳, 王巧环, 王俊杰. 分子印迹固相萃取技术及其在环境中多环芳烃测定中的应用进展[J]. 环境化学, 2022, 41(5): 1522-1529. doi: 10.7524/j.issn.0254-6108.2021120707
引用本文: 熊满艳, 王巧环, 王俊杰. 分子印迹固相萃取技术及其在环境中多环芳烃测定中的应用进展[J]. 环境化学, 2022, 41(5): 1522-1529. doi: 10.7524/j.issn.0254-6108.2021120707
XIONG Manyan, WANG Qiaohuan, WANG Junjie. Recent advances of molecularly imprinted solid-phase extraction technique and its application for the determination of polycyclic aromatic hydrocarbons in environment[J]. Environmental Chemistry, 2022, 41(5): 1522-1529. doi: 10.7524/j.issn.0254-6108.2021120707
Citation: XIONG Manyan, WANG Qiaohuan, WANG Junjie. Recent advances of molecularly imprinted solid-phase extraction technique and its application for the determination of polycyclic aromatic hydrocarbons in environment[J]. Environmental Chemistry, 2022, 41(5): 1522-1529. doi: 10.7524/j.issn.0254-6108.2021120707

分子印迹固相萃取技术及其在环境中多环芳烃测定中的应用进展

    通讯作者: Tel:010-62849387,E-mail:wangqh@rcees.ac.cn; 
  • 基金项目:
    国家重点研发计划项目(2018YFC1800306)资助

Recent advances of molecularly imprinted solid-phase extraction technique and its application for the determination of polycyclic aromatic hydrocarbons in environment

    Corresponding author: WANG Qiaohuan, 39259125@qq.com
  • Fund Project: National Key R&D Program (2018YFC1800306).
  • 摘要: 多环芳烃(Polycyclic aromatic hydrocarbons, PAHs)具有致癌性、致突变性和致畸性等毒性作用,被列为需优先控制的有机污染物。由于持久性和生物蓄积性,环境中存在的PAHs会对人体健康产生不利的影响。本文简要阐述了利用分子印迹聚合物作为吸附剂的固相萃取技术的原理及工作模式,着重介绍了其在环境中多环芳烃检测中的应用进展,并分析了当前存在的问题与应用前景。
  • 加载中
  • 图 1  分子印迹聚合物制备的示意图

    Figure 1.  Illustration on the schematic preparation of the molecular imprinted polymers

    图 2  分子印迹固相萃取技术的原理

    Figure 2.  Principle of molecularly imprinted polymers-based solid-phase extraction technology.

  • [1] HUA L T, GUO S, WANG Y, et al. Simultaneous determination of multiple isomeric hydroxylated polycyclic aromatic hydrocarbons in urine by using ultra-high performance liquid chromatography tandem mass spectrometry [J]. Journal of Chromatography B, 2021, 1184: 122983-122990. doi: 10.1016/j.jchromb.2021.122983
    [2] BENEDETTI B, di CARRO M, MAGI E. Multivariate optimization of an extraction procedure based on magnetic molecular imprinted polymer for the determination of polycyclic aromatic hydrocarbons in sea water [J]. Microchemical Journal, 2019, 145: 1199-1206. doi: 10.1016/j.microc.2018.12.048
    [3] 王勤, 袁月, 邢燕, 等. 水中多环芳烃检测技术及污染现状研究进展 [J]. 预防医学论坛, 2021, 27(7): 558-562.

    WANG Q, YUAN Y, XING Y, et al. Research progress of polycyclic aromatic hydrocarbons detection technology and pollution status in water [J]. Preventive Medicine Tribune, 2021, 27(7): 558-562(in Chinese).

    [4] YIN S, TAN H X, HUI N, et al. Polycyclic aromatic hydrocarbons in leaves of Cinnamomum camphora along the urban-rural gradient of a megacity: Distribution varies in concentration and potential toxicity [J]. Science of the Total Environment, 2020, 732: 139328-139334. doi: 10.1016/j.scitotenv.2020.139328
    [5] JAMHARI A A, LATIF M T, WAHAB M I A, et al. Size-segregated atmospheric polycyclic aromatic hydrocarbons down to PM0.1 in urban tropical environment: Temporal distribution, potential sources and human health risk [J]. Urban Climate, 2021, 40: 100996-101008. doi: 10.1016/j.uclim.2021.100996
    [6] KIM D Y, LEE B E, SHIN H S. Determination of polycyclic aromatic hydrocarbons (PAHs) in smoking cessation aids by using high-performance liquid chromatography [J]. Analytical Biochemistry, 2021, 617: 114119-114125. doi: 10.1016/j.ab.2021.114119
    [7] SABUROUH N, JABBARI A, PARASTAR H. An innovative chemometric approach for simultaneous determination of polycyclic aromatic hydrocarbons in oil-contaminated waters based on dispersive micro-solid phase extraction followed by gas chromatography [J]. Microchemical Journal, 2020, 159: 105407-105416. doi: 10.1016/j.microc.2020.105407
    [8] SÁNCHEZ N E, SALAFRANCA J, CALLEJAS A, et al. Quantification of polycyclic aromatic hydrocarbons (PAHs) found in gas and particle phases from pyrolytic processes using gas chromatography-mass spectrometry (GC-MS) [J]. Fuel, 2013, 107: 246-253. doi: 10.1016/j.fuel.2013.01.065
    [9] GILART N, BORRULL F, FONTANALS N, et al. Selective materials for solid-phase extraction in environmental analysis [J]. Trends in Environmental Analytical Chemistry, 2014, 1: e8-e18. doi: 10.1016/j.teac.2013.11.002
    [10] BRUM D M, CASSELLA R J, PEREIRA NETTO A D. Multivariate optimization of a liquid-liquid extraction of the EPA-PAHs from natural contaminated waters prior to determination by liquid chromatography with fluorescence detection [J]. Talanta, 2008, 74(5): 1392-1399. doi: 10.1016/j.talanta.2007.09.013
    [11] HWANG S, CUTRIGHT T J. Preliminary evaluation of PAH sorptive changes in soil by Soxhlet extraction [J]. Environment International, 2004, 30(2): 151-158. doi: 10.1016/S0160-4120(03)00158-2
    [12] OH J Y, CHOI S D, KWON H O, et al. Leaching of polycyclic aromatic hydrocarbons (PAHs) from industrial wastewater sludge by ultrasonic treatment [J]. Ultrasonics Sonochemistry, 2016, 33: 61-66. doi: 10.1016/j.ultsonch.2016.04.027
    [13] 王春琼, 李苓, 李振杰, 等. 分子印迹固相萃取技术在农药残留检测中的应用进展 [J]. 江西农业学报, 2021, 33(6): 59-64.

    WANG C Q, LI L, LI Z J, et al. Application of molecularly imprinted solid-phase extraction in determination of pesticide residues [J]. Acta Agriculturae Jiangxi, 2021, 33(6): 59-64(in Chinese).

    [14] YU C, WU F S, LUO X G, et al. Porphyrin-based covalent organic framework coated stainless steel fiber for solid-phase microextraction of polycyclic aromatic hydrocarbons in water and soil samples [J]. Microchemical Journal, 2021, 168: 106364-106372. doi: 10.1016/j.microc.2021.106364
    [15] BROWN J N, PEAKE B M. Determination of colloidally-associated polycyclic aromatic hydrocarbons (PAHs) in fresh water using C18 solid phase extraction disks [J]. Analytica Chimica Acta, 2003, 486(2): 159-169. doi: 10.1016/S0003-2670(03)00472-0
    [16] PAN D, WANG J P, CHEN C Y, et al. Ultrasonic assisted extraction combined with titanium-plate based solid phase extraction for the analysis of PAHs in soil samples by HPLC-FLD [J]. Talanta, 2013, 108: 117-122. doi: 10.1016/j.talanta.2013.02.066
    [17] AZIZI A, BOTTARO C S. A critical review of molecularly imprinted polymers for the analysis of organic pollutants in environmental water samples [J]. Journal of Chromatography A, 2020, 1614: 460603-460637. doi: 10.1016/j.chroma.2019.460603
    [18] KRUPADAM R J, KHAN M S, WATE S R. Removal of probable human carcinogenic polycyclic aromatic hydrocarbons from contaminated water using molecularly imprinted polymer [J]. Water Research, 2010, 44(3): 681-688. doi: 10.1016/j.watres.2009.09.044
    [19] MARANATA G J, SURYA N O, HASANAH A N. Optimising factors affecting solid phase extraction performances of molecular imprinted polymer as recent sample preparation technique [J]. Heliyon, 2021, 7(1): e05934-e05945. doi: 10.1016/j.heliyon.2021.e05934
    [20] ZHANG C, XING H F, YANG L R, et al. Development trend and prospect of solid phase extraction technology[J]. Chinese Journal of Chemical Engineering, 2021, 45:245-255.
    [21] MAURI-AUCEJO A, AMORÓS P, MORAGUES A, et al. Comparison of the solid-phase extraction efficiency of a bounded and an included cyclodextrin-silica microporous composite for polycyclic aromatic hydrocarbons determination in water samples [J]. Talanta, 2016, 156/157: 95-103. doi: 10.1016/j.talanta.2016.05.011
    [22] COSTA J A S, de JESUS R A, da SILVA C M P, et al. Efficient adsorption of a mixture of polycyclic aromatic hydrocarbons (PAHs) by Si-MCM-41 mesoporous molecular sieve [J]. Powder Technology, 2017, 308: 434-441. doi: 10.1016/j.powtec.2016.12.035
    [23] ZHAO J, WANG Z Y, ZHAO Q, et al. Adsorption of phenanthrene on multilayer graphene as affected by surfactant and exfoliation [J]. Environmental Science & Technology, 2014, 48(1): 331-339.
    [24] WANG Y X, WANG S H, NIU H Y, et al. Preparation of polydopamine coated Fe3O4 nanoparticles and their application for enrichment of polycyclic aromatic hydrocarbons from environmental water samples [J]. Journal of Chromatography A, 2013, 1283: 20-26. doi: 10.1016/j.chroma.2013.01.110
    [25] XUE S W, TANG M Q, XU L, et al. Magnetic nanoparticles with hydrophobicity and hydrophilicity for solid-phase extraction of polycyclic aromatic hydrocarbons from environmental water samples [J]. Journal of Chromatography A, 2015, 1411: 9-16. doi: 10.1016/j.chroma.2015.07.104
    [26] YAZDANPANAH M, NOJAVAN S. Cyclodextrin-starch hard gel as an efficient green sorbent for dispersive micro solid-phase extraction of eight polycyclic aromatic hydrocarbons from environmental water samples [J]. Microchemical Journal, 2021, 168: 106509-106518. doi: 10.1016/j.microc.2021.106509
    [27] ATIRAH MOHD NAZIR N, RAOOV M, MOHAMAD S. Spent tea leaves as an adsorbent for micro-solid-phase extraction of polycyclic aromatic hydrocarbons (PAHs) from water and food samples prior to GC-FID analysis [J]. Microchemical Journal, 2020, 159: 105581-105587. doi: 10.1016/j.microc.2020.105581
    [28] YANG X P, YIN Y R, ZONG Y Y, et al. Magnetic nanocomposite as sorbent for magnetic solid phase extraction coupled with high performance liquid chromatography for determination of polycyclic aromatic hydrocarbons [J]. Microchemical Journal, 2019, 145: 26-34. doi: 10.1016/j.microc.2018.10.013
    [29] MAJD M, NOJAVAN S. Determination of polycyclic aromatic hydrocarbons in soil, tree leaves, and water samples by magnetic dispersive solid-phase extraction based on β-cyclodextrin functionalized graphene oxide followed by GC-FID [J]. Microchemical Journal, 2021, 171: 106852-106862. doi: 10.1016/j.microc.2021.106852
    [30] YAN X Q, GUO Y N, ZHENG S J, et al. Solid phase extraction of 16 polycyclic aromatic hydrocarbons from environmental water samples by π-hole bonds [J]. Journal of Chromatography A, 2021, 1645: 462067-462074. doi: 10.1016/j.chroma.2021.462067
    [31] 押浩博, 姜博, 邢奕, 等. 分子印迹技术在水环境抗生素富集中的应用进展 [J]. 环境化学, 2021, 40(2): 343-354. doi: 10.7524/j.issn.0254-6108.2020052902

    YA H B, JIANG B, XING Y, et al. Recent advances of molecularly imprinted technology in the enrichment of antibiotics in aquatic environment [J]. Environmental Chemistry, 2021, 40(2): 343-354(in Chinese). doi: 10.7524/j.issn.0254-6108.2020052902

    [32] 许祯毅, 吴玉琼, 范俐, 等. 分子印迹技术在食品安全检测领域的应用进展 [J]. 食品研究与开发, 2021, 42(3): 207-212.

    XU Z Y, WU Y Q, FAN L, et al. Application progress of molecular imprinting technology in food safety detection [J]. Food Research and Development, 2021, 42(3): 207-212(in Chinese).

    [33] MOSTAFA A M, BARTON S J, WREN S P, et al. Review on molecularly imprinted polymers with a focus on their application to the analysis of protein biomarkers [J]. TrAC Trends in Analytical Chemistry, 2021, 144: 116431-116468. doi: 10.1016/j.trac.2021.116431
    [34] XIE J Q, CAI C Q, LAI S Z, et al. Synthesis and application of a molecularly imprinted polymer as a filter to reduce polycyclic aromatic hydrocarbon levels in mainstream cigarette smoke [J]. Reactive and Functional Polymers, 2013, 73(12): 1606-1611. doi: 10.1016/j.reactfunctpolym.2013.09.003
    [35] EGLI S N, BUTLER E D, BOTTARO C S. Selective extraction of light polycyclic aromatic hydrocarbons in environmental water samples with pseudo-template thin-film molecularly imprinted polymers [J]. Analytical Methods, 2015, 7(5): 2028-2035. doi: 10.1039/C4AY02849J
    [36] FLOTRON V, DELTEIL C, PADELLEC Y, et al. Removal of sorbed polycyclic aromatic hydrocarbons from soil, sludge and sediment samples using the Fenton's reagent process [J]. Chemosphere, 2005, 59(10): 1427-1437. doi: 10.1016/j.chemosphere.2004.12.065
    [37] KRUPADAM R J, KORDE B A, ASHOKKUMAR M, et al. Novel molecularly imprinted polymeric microspheres for preconcentration and preservation of polycyclic aromatic hydrocarbons from environmental samples [J]. Analytical and Bioanalytical Chemistry, 2014, 406(22): 5313-5321. doi: 10.1007/s00216-014-7952-z
    [38] KRUPADAM R J, NESTEROV E E, SPIVAK D A. Highly selective detection of oil spill polycyclic aromatic hydrocarbons using molecularly imprinted polymers for marine ecosystems [J]. Journal of Hazardous Materials, 2014, 274: 1-7. doi: 10.1016/j.jhazmat.2014.03.050
    [39] MUNAWAR H, MANKAR J S, SHARMA M D, et al. Highly selective electrochemical nanofilm sensor for detection of carcinogenic PAHs in environmental samples [J]. Talanta, 2020, 219: 121273-121279. doi: 10.1016/j.talanta.2020.121273
    [40] NCUBE S, KUNENE P, TAVENGWA N T, et al. Synthesis and characterization of a molecularly imprinted polymer for the isolation of the 16 US-EPA priority polycyclic aromatic hydrocarbons (PAHs) in solution [J]. Journal of Environmental Management, 2017, 199: 192-200.
    [41] NCUBE S, TAVENGWA N, SOQAKA A, et al. Development of a single format membrane assisted solvent extraction-molecularly imprinted polymer technique for extraction of polycyclic aromatic hydrocarbons in wastewater followed by gas chromatography mass spectrometry determination [J]. Journal of Chromatography A, 2018, 1569: 36-43. doi: 10.1016/j.chroma.2018.07.061
    [42] HIJAZI H Y, BOTTARO C S. Molecularly imprinted polymer thin-film as a micro-extraction adsorbent for selective determination of trace concentrations of polycyclic aromatic sulfur heterocycles in seawater [J]. Journal of Chromatography A, 2020, 1617: 460824-460831. doi: 10.1016/j.chroma.2019.460824
    [43] ÇORMAN M E, ARMUTCU C, UZUN L, et al. Rapid, efficient and selective preconcentration of benzo[a]Pyrene (BaP) by molecularly imprinted composite cartridge and HPLC [J]. Materials Science and Engineering:C, 2017, 70: 41-53. doi: 10.1016/j.msec.2016.08.040
    [44] 王新鑫, 杨军, 谢晟瑜, 等. 基于分子印迹磁性复合材料的基质分散-固相萃取/液相色谱法测定海水中的氯酚类污染物 [J]. 分析测试学报, 2015, 34(11): 1213-1219. doi: 10.3969/j.issn.1004-4957.2015.11.001

    WANG X X, YANG J, XIE S Y, et al. Analysis of chlorophenols in seawater samples by molecular imprinted magnetic composite-based dispersive solid phase extraction coupled with liquid chromatography [J]. Journal of Instrumental Analysis, 2015, 34(11): 1213-1219(in Chinese). doi: 10.3969/j.issn.1004-4957.2015.11.001

    [45] SUN X L, WANG J C, LI Y, et al. Novel dummy molecularly imprinted polymers for matrix solid-phase dispersion extraction of eight fluoroquinolones from fish samples [J]. Journal of Chromatography A, 2014, 1359: 1-7. doi: 10.1016/j.chroma.2014.07.007
    [46] ANSELL R J, MOSBACH K. Magnetic molecularly imprinted polymer beads for drug radioligand binding assay [J]. The Analyst, 1998, 123(7): 1611-1616. doi: 10.1039/a801903g
    [47] LIU Y H, LIAN Z R, LI F F, et al. Review on molecular imprinting technology and its application in pre-treatment and detection of marine organic pollutants [J]. Marine Pollution Bulletin, 2021, 169: 112541-112555. doi: 10.1016/j.marpolbul.2021.112541
    [48] MULLETT W M, MARTIN P, PAWLISZYN J. In-tube moleculary imprinted polymer solid-phase microextraction for the selective determination of propranolol [J]. Analytical Chemistry, 2001, 73(11): 2383-2389. doi: 10.1021/ac0100502
    [49] TURIEL E, MARTÍN-ESTEBAN A. Molecularly imprinted polymers-based microextraction techniques [J]. TrAC Trends in Analytical Chemistry, 2019, 118: 574-586. doi: 10.1016/j.trac.2019.06.016
    [50] LIU Y, HUANG Y T, WANG D M, et al. Molecularly imprinted polymers hydrogel for the rapid risk-category-specific screening of food using SPE followed by fluorescence spectrometric detection [J]. Microchemical Journal, 2020, 159: 105408-105413. doi: 10.1016/j.microc.2020.105408
    [51] FU X, ZHU D L, HUANG L, et al. Superparamagnetic core-shell dummy template molecularly imprinted polymer for magnetic solid-phase extraction of food additives prior to the determination by HPLC [J]. Microchemical Journal, 2019, 150: 104169-104176. doi: 10.1016/j.microc.2019.104169
    [52] CARO E, MARCÉ R M, BORRULL F, et al. Application of molecularly imprinted polymers to solid-phase extraction of compounds from environmental and biological samples [J]. TrAC Trends in Analytical Chemistry, 2006, 25(2): 143-154. doi: 10.1016/j.trac.2005.05.008
    [53] MADIKIZELA L M, TAVENGWA N T, CHIMUKA L. Applications of molecularly imprinted polymers for solid-phase extraction of non-steroidal anti-inflammatory drugs and analgesics from environmental waters and biological samples [J]. Journal of Pharmaceutical and Biomedical Analysis, 2018, 147: 624-633. doi: 10.1016/j.jpba.2017.04.010
    [54] SONG X L, LI J H, XU S F, et al. Determination of 16 polycyclic aromatic hydrocarbons in seawater using molecularly imprinted solid-phase extraction coupled with gas chromatography-mass spectrometry [J]. Talanta, 2012, 99: 75-82. doi: 10.1016/j.talanta.2012.04.065
    [55] 李成, 张雪娜, 师耀龙, 等. 分子印迹固相萃取-气相色谱/质谱联用法测定污泥中多环芳烃 [J]. 环境化学, 2017, 36(1): 190-197. doi: 10.7524/j.issn.0254-6108.2017.01.2016032203

    LI C, ZHANG X N, SHI Y L, et al. Determination of polycyclic aromatic hydrocarbons in sludge by molecular imprinting solid phase extraction and gas chromatography/mass spectrometry [J]. Environmental Chemistry, 2017, 36(1): 190-197(in Chinese). doi: 10.7524/j.issn.0254-6108.2017.01.2016032203

    [56] VILLAR-NAVARRO M, MARTÍN-VALERO M J, FERNÁNDEZ-TORRES R M, et al. Easy, fast and environmental friendly method for the simultaneous extraction of the 16 EPA PAHs using magnetic molecular imprinted polymers (mag-MIPs) [J]. Journal of Chromatography B, 2017, 1044/1045: 63-69. doi: 10.1016/j.jchromb.2016.12.009
    [57] AZIZI A, SHAHHOSEINI F, BOTTARO C S. Magnetic molecularly imprinted polymers prepared by reversible addition fragmentation chain transfer polymerization for dispersive solid phase extraction of polycyclic aromatic hydrocarbons in water [J]. Journal of Chromatography A, 2020, 1610: 460534-460548. doi: 10.1016/j.chroma.2019.460534
  • 加载中
图( 2)
计量
  • 文章访问数:  2478
  • HTML全文浏览数:  2478
  • PDF下载数:  53
  • 施引文献:  0
出版历程
  • 收稿日期:  2021-12-07
  • 录用日期:  2022-04-08
  • 刊出日期:  2022-05-27

分子印迹固相萃取技术及其在环境中多环芳烃测定中的应用进展

    通讯作者: Tel:010-62849387,E-mail:wangqh@rcees.ac.cn; 
  • 中国科学院生态环境研究中心城市与区域生态国家重点实验室,北京,100085
基金项目:
国家重点研发计划项目(2018YFC1800306)资助

摘要: 多环芳烃(Polycyclic aromatic hydrocarbons, PAHs)具有致癌性、致突变性和致畸性等毒性作用,被列为需优先控制的有机污染物。由于持久性和生物蓄积性,环境中存在的PAHs会对人体健康产生不利的影响。本文简要阐述了利用分子印迹聚合物作为吸附剂的固相萃取技术的原理及工作模式,着重介绍了其在环境中多环芳烃检测中的应用进展,并分析了当前存在的问题与应用前景。

English Abstract

  • 多环芳烃(Polycyclic aromatic hydrocarbons, PAHs)是一类具有两个或多个苯环结构的稠环化合物,广泛存在于大气、土壤和水等环境介质中[1]。当前已经发现的PAHs有200多种,多具有致癌性、致突变性、致畸性等毒性作用,其中16种已被美国环境保护署(EPA)列为优先控制的有机污染物[2]。环境中的PAHs主要有两种来源,一是来自火山爆发、森林火灾等自然因素,二是来源于汽车尾气排放和化学燃料不完全燃烧等人为因素[3]。研究表明,人体受到环境中的PAHs的暴露后,可进入消化道、呼吸道和皮肤,进而影响人体健康[4]。同时,PAHs具有高生物蓄积性,这使得环境中微量PAHs暴露也可能会对人体的健康造成严重的威胁[5]。为了更好地监测环境安全,防止PAHs超标带来的环境安全隐患,必须对环境中的多环芳烃进行监测。

    目前,已经构建的PAHs检测方法包括液相色谱法(LC)[6]、气相色谱法(GC)[7]、气相色谱-质谱联用法(GC-MS)等[8],但由于PAHs在大气、水体和土壤中的含量较低,甚至是痕量存在,且环境基质复杂,无论采用何种检测方法,分析复杂环境基质中的痕量PAHs均需进行高效且选择性的样品预处理,以便获得更“纯净”的提取物,从而加强样品中多环芳烃的响应度,并减少复杂基质对检测结果的影响。因此,建立快捷、高效的前处理方法对提高测定PAHs的效率和增强检测结果的可靠性具有重要意义[9].

    目前已经广泛应用于环境中PAHs前处理的方法有液-液萃取[10]、索氏提取[11]和超声辅助提取[12]等,但这些方法往往存在处理时间长和溶剂消耗多等缺点[13],更重要的是这些方法缺乏选择性,导致提取后的样品中含有众多的干扰物质,进而会影响测定的灵敏度和重复性。固相萃取技术(Solid-phase extraction, SPE)自20世纪70年代问世以来,由于操作简便、处理时间短、萃取精度高和易与LC、GC、GC-MS等检测仪器联用等优点,已被成功应用于水和土壤中PAHs的测定[14-16]。然而,传统的固相萃取吸附剂材料依然存在特异性低和重现性差的问题,这也限制了其在测定复杂环境基质中PAHs的应用。为进一步解决这一问题,亟待寻找特异性高、重复性好的吸附材料或方法。近年来,分子印迹聚合物(Molecularly imprinting polymers, MIPs)由于吸附特异性高、制备简单且可重复使用等优点有效弥补了固相萃取传统吸附材料的不足,在PAHs检测中显示出良好的应用前景[17-18]

    本文概述了固相萃取技术、分子印迹聚合物及两者结合应用的原理,着重介绍了其在环境中PAHs检测中的应用进展,并分析了当前存在的问题与应用前景,旨在为快速、有效地测定环境中的PAHs提供参考。

    • SPE因成本低、操作简单[19]在样品前处理领域得到广泛应用,其原理是利用固体吸附材料物理性吸附样品中的目标物质,使其与样品中的“杂质”分离,再利用加热处理或洗脱液洗脱将目标化合物解吸附,从而达到有效分离和富集目标化合物的目的[20]。其中,固体吸附材料对分离和富集目标化合物的效果起着至关重要的作用。常用的固体吸附材料包括活性炭、有机高分子树脂、键合硅胶等,但这些吸附材料往往存在选择性差的弊端,难以从复杂的样品基质中提取富集“纯净”的化合物,为后续的测定工作带来一定的难度。

    • 近年来,介孔有机二氧化硅[21]、介孔二氧化硅纳米颗粒[22]、碳纳米管[23]、金属氧化物纳米颗粒[24]和功能磁性纳米颗粒[25]等一系列新型SPE材料被陆续应用于环境样品中PAHs的预处理。Yazdanpanah等[26]以β-环糊精-淀粉复合物为SPE材料,结合气相色谱-氢火焰离子化检测器(GC-FID)构建了雨水中8种PAHs(萘、苊、芴、菲、蒽、荧蒽、芘和苯并[a]芘)的检测方法,在0.1—1000 ng·mL−1范围内具有良好的线性关系,检测限为0.01—0.07 ng·mL−1,定量限在0.04—0.24 ng·mL−1,富集因子在84—95。Nazir等[27]使用低成本的废弃茶叶作为SPE吸附剂,利用GC-FID成功测定了河水中芴、荧蒽、芘、芘和苯并[a]芘的含量,其线性范围为50—1000 ng·mL−1,回收率为88.0%—111.4%,相对标准偏差为1.0%—9.8%。Yang等[28]制备了一种新型磁性材料Fe3O4@SiO2@MMTA-Au作为SPE的吸附剂,从河流和降水中提取富集了14种目标PAHs(萘、芴、苊、菲、芘、蒽、荧蒽、苯并[a]芘、苯并[a]蒽、苯并[b]荧蒽、苯并[k]荧蒽、二苯并[a,h]蒽、茚并[1,2,3-cd]芘和苯并[g,h,i]苝),然后用HPLC-FLD测定了各PAHs的浓度,其检测限为0.25—37.5 ng·L−1,回收率为87.8%—120.0%,富集因子为80—98。Majd等[29]首次合成了一种纳米复合材料作为SPE吸附剂,结合GC-FID成功应用于土壤、树叶和和水中PAHs(萘、苊、芴、菲、荧蒽、芘、苯并[a]芘)的提取、富集和含量测定,其线性范围为5.0—1000 ng·mL−1,检测限为0.1—0.5 ng·mL−1,回收率为73.0%—97.1%,相对标准偏差小于8.0%,富集因子在46—62。Yan[30]等合成全氟苯键合硅胶用作SPE吸附剂,用于河水和废水中16种PAHs的固相萃取,与传统的十八烷基硅胶吸附剂相比,该吸附剂对具有4—6个苯环的PAHs表现出更高的吸附能力,检测限范围为0.002—0.08 μg·L−1,回收率均提高了约20%。上述研究表明,新型吸附剂确实能有效提高SPE的萃取能力,并可应用于实际环境中PAHs的提取,然而该类吸附剂依然存在选择特异性差的弊端,对后续仪器分析定量检测会造成一定影响。

    • MIPs的制备原理如图1所示,主要涉及模板分子、功能单体、引发剂和交联剂,其中功能单体与模板分子先结合形成配合物,引发剂和交联剂的加入会进一步引发聚合形成高交联度的刚性聚合物,当模板分子被洗脱除去后,聚合物内就会形成与模板分子具有相同形状和大小的空腔[31]。因此,模板分子与MIPs聚合物内的空腔类似于“分子钥匙”和锁,MIPs空穴内“钥匙分子”的结合位点可以重新识别模板分子并与之结合,从而达到精准选择与分离目标化合物的目的。现有研究表明,MIPs在成分复杂的样品基质中有较高的稳定性,对恶劣的环境具有较好的抵抗性[32]、选择性和重复利用率。

      三维网络结构是MIPs的主要结构特征,而功能单体、模板分子、交联剂、引发剂和致孔剂是制备MIPs的必要材料。功能单体在分子印迹中起着至关重要的作用,它们在MIPs的制备和提取过程中需与模板分子和目标分子相结合[33],因此应选择能与目标分子相结合的功能单体。但当前开发的功能单体还较少,常用的有苯基三甲氧基硅烷、甲基丙烯酸、2-乙烯基吡啶,4-乙烯基吡啶、异丙基丙烯酰胺、乙烯基苯、甲基丙烯酸缩水甘油酯、N-异丙基丙烯酰胺、甲基丙烯酸2-羟乙酯、丙烯酸、丙烯酰胺、甲基丙烯酸甲酯、2-甲基丙烯酸羟乙酯等。模板分子既要能与功能单体相聚合,还需要在洗脱过程中容易去除[33],因此理想的模板分子不仅要含有与功能单体相互作用的官能团,而且不能干扰聚合反应。此外,不同反应条件(pH、温度等)也可能会影响模板分子的化学稳定性,进而影响MIPs的结构。交联剂是稳定模板分子与功能单体结合位点并赋予聚合物三维结构机械稳定性的重要因素[33],能保留移除模板分子的记忆;不同的交联剂会导致结合位点的不同,对MIPs的平均粒径和表面均一性也有一定的影响。因此,所选交联剂应该与功能单体具有相似的反应性,且交联剂的浓度不应过低,否则会降低MIPs的机械稳定性,但过高的浓度会减少单位质量MIPs的结合位点数量,且会在交联剂与模板或交联剂与单体之间发生侧向非共价相互作用进而破坏选择性。常用的交联剂有乙二醇二甲基丙烯酸酯、N,N′-亚甲基二丙烯酰胺、二乙烯基苯、四乙氧基硅烷、三羟甲基丙烷三甲基丙烯酸酯、季戊四醇三丙烯酸酯等。引发剂的主要原理是使用自由基来引发聚合反应,这些引发剂通过热分解或紫外线辐射产生自由基,一旦形成,自由基就会通过与所有物质开始连接聚合[33]。最常用引发剂有偶氮二异丁腈、硅酸乙酯、偶氮二异庚腈、过硫酸钾、过氧化苯甲酰、过硫酸铵、3-溴丙基三甲氧基硅烷等。溶剂主要作用是溶解反应中的所有起始材料,并充当成孔剂,有利于模板分子接近MIPs的结合位点[33]。溶剂不仅关乎着键的结合强度,还会影响MIPs的形态。一般来说,极性较小的溶剂,如甲苯和二氯甲烷,更加利于增强MIPs的识别能力。

    • 目前,已经设计出多种PAHs对应的MIPs[34-36],并通过不断优化MIPs的特异性以便能更有效地应用于环境中PAHs的检测。Krupadam等[18]以甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,使用6种PAHs混合物(苯并[a]蒽、苯并[a]芘、苯并[b]荧蒽、䓛、二苯并[a,h]芘、茚并[1,2,3-cd]芘)作为模板,采用本体聚合法构建了MIPs,该材料能有效吸附地下水中的PAHs,最大吸附量达687 mg·g−1,且经10次再生实验后,吸附性能并未受到显著影响。在后续的研究中[37],采用相同的功能单体和交联剂制备MIPs微球,成功从环境水样中选择性分离苯并[a]芘,吸附能力达到75 mg·g−1,比商业使用的活性炭高出近300%。2014年,Krupadam等[38]开发了新的功能性交联剂N,O-双甲基丙烯酰乙醇胺,以芘为模板分子构建了MIPs,发现该MIPs对海水中芘的吸附能力达到35 mg·g−1,是非模板分子印迹聚合物(NIPs)的9.6倍,且对䓛和苯并[a]芘的交叉选择性只有5.5%和7.0%。Munawar等[39]使用4-乙烯基吡啶与目标芘进行电聚合形成芘MIPs薄膜,并基于该薄膜设计了一款传感器用于水中PAHs的测定,其检测限达0.001 ng·L−1,回收率为83%—110%,与其他传感器相比,该基于MIPs的纳米膜传感器具有最高的灵敏度。Ncube等[40]以苯乙烯为功能单体,乙二醇二甲基丙烯酸酯为交联剂,4,4-偶氮(4-氰基戊酸)为引发剂,使用苯并[k]荧蒽和茚并[1,2,3-cd]芘为模板分子构建了两种MIPs,并将其按照1∶1的比例混合,用于环己烷溶液中PAHs的分离,结果发现该方法对所有16种有毒性的PAHs均显示出高选择性和亲和力,其平均提取效率为65% ± 13.3%,当溶液中PAHs过量时,MIPs空腔的总体占据程度能达到128% ± 6.45%,且每个洗脱循环损失率仅为2.9%;在后继研究中,使用该MIPs结合膜辅助索氏提取法及GC-MS实现了对污泥中的16种PAHs的测定,其检测限为0.14—12.86 ng·g−1,相对标准偏差值为0.78%—18%[41]。Hijazi等[42]1-乙烯基咪唑为功能单体制备了一种多孔MIPs薄膜,并用作微萃取吸附剂。结合GC-MS检测,提供了一种适用于测定海水中痕量PAHs硫杂环化合物含量的方法。Corman等[43]以甲基丙烯酸2-羟乙基酯为功能单体,乙二醇二甲基丙烯酸酯为交联剂制备苯并芘MIPs,在水中预富集苯并芘的效率为349.6%,回收率达到87.39%。

    • 分子印迹固相萃取(Molecularly imprinted solid-phase extraction technology,MISPE)技术的原理如图2所示,是以分子印迹聚合物为固相萃取吸附剂的固相萃取技术,克服了传统固相萃取吸附剂选择性差的问题,可以有效提高目标分子的选择性和吸附能力,大大降低痕量分子的检测难度[13]。采用MISPE进行样品预处理包括离线和在线两种模式。离线模式[13]包括MISPE柱子的调节、样品装载、“杂质”洗涤和目标分子洗脱等4个环节,洗脱液用于LC、GC或GC-MS等后继分析,其主要优点是操作简单,溶剂过量对后续分析的影响较小,可以充分洗脱目标分子,但分离、预浓缩等过程中存在目标分子损失和被污染的风险,且操作过程繁琐耗时,可能增加后续测定时的误差。在线模式[13]实现了MISPE的自动化,即自动加载样品、洗涤“杂质”、洗脱目标分子及检测目标分子的含量,减少了实际样品的预处理时间,降低了目标物损失和被污染的风险,从而提高了检测的准确性和重现性。然而,当改变洗脱溶剂的pH时可能会对色谱分离造成一定的影响。

    • 2015年,王新鑫等[44]利用基质分散分子印迹固相萃取技术(MI-MSPD)检测海水中痕量的氯酚,其将磁性MIPs吸附剂与样品通过研磨等方式分散混合后一同填充至固相萃取柱内,再经适当的洗涤步骤除去干扰化合物,最后选用适当溶剂洗脱目标分子。该法所需样品量小,目标分子与洗脱溶剂的接触面较大,溶剂可渗透至样品基质内,有利于充分洗脱目标分子,但研磨的强度、速度和时间等参数对其吸附性能和重复性有较大影响[45]

    • 1998年,Ansell和Mosbach[46]首次将分子印迹与磁性铁氧化物相结合制备了具有超顺磁性的磁性分子印迹聚合物微球(MMIPs),并将其应用于溶液中目标分子的吸附。由于MMIPs可在外加磁场作用下实现与溶液的分离,无需过滤或离心等操作,具有操作简单和耗时短的显著优势,在固相萃取领域得到了极大发展[47]

    • 2001年,Mullet等[48]首次提出了分子印迹技术固相微萃取技术(MISPME),其将MIPs研磨成具有一定粒度的颗粒并装入毛细管中,利用一套自动的在线装置分析尿液中心得安的含量。SPME主要包含吸附和解吸两个过程,吸附过程中目标分子可在纤维涂层外的固定相中通过物理吸附快速达到平衡分配,后续解吸过程则主要取决于所用的检测方法,如与GC联用时采用通过热解吸方法,而与HPLC联用时则可采用溶剂洗脱。SPME技术操作简便,灵敏度高,吸附材料可重复使用,但对目标分子的选择性较差。搅拌棒吸附萃取(SBSE)是基于与SPME相同的原理,将MIPs吸附剂涂覆在磁力搅拌棒上而实现分离的一种技术,它提供了大量的吸附剂相,有助于提高目标分子的回收率,但平衡时间较长[49]

    • 现阶段,基于MIPs的SPE的样品前处理方法已经广泛用于食品和生物领域[50-53],但在检测环境中PAHs方面仍处于起步阶段。Song等[54]以苯基三甲氧基硅烷为功能单体,用四乙氧基硅烷作交联剂,乙酸为引发剂,采用16种PAHs标准品为模板分子制备MIPs作为SPE吸附剂,并结合GC-MS成功测定了海水样品中的16种PAHs,其检测限为5.2—12.5 ng·L−1,回收率达83%—113%,相对标准偏差为3.2%—7.5%。李成等[55]提出了采用16种PAHs标准品为混合模板制备MIPs,并结合SPE与GC-MS实现了对污泥中的多环芳烃的特异性富集、分离与检测,结果显示该方法较为适合测定中环和高环的PAHs。Navarro等[56]提出基于磁性分子印迹聚合物与高效液相色谱相结合测定河水中16种PAHs的方法,其对亲脂性PAHs的回收率为98.8%—100%,但对亲脂性较低PAHs的回收率较差,为46%—60%;其对蒽的检出限最低(1.3 ng·L−1),对苊的检出限最高(969 ng·L−1)。Benedetti等[2]基于沉淀聚合法构建了磁性MIPs固相萃取方法,并与GC-MS相结合用于海水中PAHs的检测,其对低分子量PAHs的回收率为76%—104%,高分子量PAHs的回收率为95%—101%,检出限范围为30—375 ng·L−1,相对标准偏差为3.7%—12.2%。Azizi等[57]使用甲基丙烯酸和异丙基丙烯酰胺作为双功能单体,以乙二醇二甲基丙烯酸酯为交联剂,偶氮二异丁腈为引发剂,通过沉淀聚合法成功构建了MIPs,结合SPE方法对河水样品进行离线处理后,使用气相色谱-大气压化学电离串联质谱(APGC-MS/MS)测定其中PAHs,结果表明该方法的检出限在1—100 ng·L−1,准确度为72%—135%,且对PAHs的吸附能力高于Fe3O4和Fe3O4@SiO2。可以预测,越来越多以PAHs为模板的分子印迹固相萃取技术将应用于环境中的PAHs的检测。

    • MIPs具有选择性高、稳定性好、可重复使用等众多优点,而SPE易与LC和GC等分析仪器联用,因此以MIPs为吸附材料的SPE技术已陆续应用于环境中PAHs的测定。但是,相关研究尚处于起步阶段,有许多问题亟待解决:一是MIPs在制备过程中会用到大量PAHs的模板分子,尽管制备后要经过充分洗脱,但也会有5%左右的模板分子残余在MIPs中,模板分子的泄漏可能会影响痕量化合物后续检测结果;二是MIPs与目标分子的识别和结合主要以氢键作用实现的,而水分子既是氢键受体,又是供体,因此在水溶液中提取目标分子时水分子会竞争性破坏模板和功能单体之间的氢键,导致MIPs的识别能力大大降低,从而使得选择性有所下降;三是MIPs的吸附容量偏低,且用于制备MIPs的功能单体的选择有限。因此,提高模板分子的洗脱率以降低模板分子泄漏对PAHs的测定影响,提供更多的吸附位点以增强对PAHs分子的识别能力,寻找针对性的功能单体分子以克服MIPs在水溶液中的氢键作用,将成为今后针对环境中PAHs分子印迹固相萃取技术的重要研究方向。尽管分子印迹固相萃取技术尚存在一定的局限和不足,但鉴于其出色的选择性、稳定性和可重复利用性,其在检测环境中痕量PAHs的检测中必将发挥更重要的作用。

    参考文献 (57)

目录

/

返回文章
返回