【作者】 陶涌；

【导师】 江桂斌； 刘景富；

【作者基本信息】 中国科学技术大学 ， 环境科学， 2009， 博士

【摘要】 样品前处理技术在有机污染物分析中有着十分重要的地位,它直接影响到分析结果的准确性。为了克服常规使用的液-液萃取等环境有机污染物样品前处理技术操作步骤繁琐、处理时间长、有机溶剂用量大的缺点,分析工作者提出了许多新的前处理技术如固相萃取、固相微萃取、膜萃取、微波辅助萃取、加速溶剂萃取、液相微萃取等,这些技术的共同特点是使用的有机溶剂少,被称为绿色样品前处理技术。本文在对这些技术进行综述的基础上,对基于支载液膜的液相微萃取技术进行了较为系统的研究。中空纤维支载液膜液相微萃取(HF-SLM)是近年来发展起来的一种新型的样品前处理技术,该技术集采样、萃取和浓缩于一体,需要有机溶剂量非常少,是一种环境友好的萃取技术。这种技术主要与气相色谱-或液相色谱-质谱(GC-MS、LC-MS)、高效液相色谱(HPLC)和毛细管电泳(CE)等仪器联用,用于一些难挥发和半挥发性环境污染物以及生物样品中低浓度药物残留的分析。本论文在前人工作的基础上,围绕样品前处理技术,开展了以下几个方面的研究工作:(1)发展了一种中空纤维支载聚丙二醇(PPG)薄膜被动采样装置,用于环境水体中痕量异味化合物2-甲基异茨醇和土腥素的采样分析。实验优化了采样装置的制备材料和方法,考察了采样时间、样品盐度和pH值等对采样效率的影响,发现PPG 4000对2-甲基异茨醇和土腥素较高的分离富集能力。将该被动采样装置与顶空固相微萃取-气相色谱/质谱联用,获得了较低的检测限0.1 ng/L)。该被动采样装置已成功用于太湖水体中2-甲基异茨醇和土腥素的野外被动采样。(2)发展了一种基于中空纤维支载液膜技术同时进行两相和三相萃取的复合微萃取模式,用于分离富集环境水样中的芳香胺类化合物。结合高效液相色谱(HPLC)分析测定,该方法所获得的富集倍数为415-2000,检测限0.5-1.5μg/L,线性范围5-200μg/L(r>0.9976)。同时,对实际环境样品进行了加标回收测定,得到了较好的回收率(80-103%),很好地消除了基质的干扰。(3)利用离子液体的较强极性和对目标化合物的良好溶解性能,将其应用于中空纤维支载液膜三相微萃取体系,通过HPLC/UV检测分析,建立了环境水样中两性磺胺药物残留的分析方法。由于中空纤维支载离子液体液膜具有较好的稳定性,分析测定的结果也具有较好的重现性。对5种环境样品加入5μg/L磺胺类标准,方法测得的相对加标回收率为82.2%-103.2%(RSD≤5%)。更多还原

【Abstract】 Sample pretreatment technology plays an important role in analyzing organic pollutants.The accuracy of the results strongly dependent on the sample pretreatment process.In order to overcome the disadvantage of tedious workup,large amounts of toxic organic solvent usage in the classical LLE extraction of environmental organic pollutants,many novel methods have been developed,such as solid phase extraction （SPE）,solid phase microextraction（SPME）,membrane extraction（ME）,microwave assisted extraction（MAE）,accelerated solvent extraction（ASE）,and liquid phase microextraction（LPME）.As these methods use small or no organic solvents,they are regarded as green pretreatment technology.This thesis systematically studied the application of hollow fiber supported liquid membrane liquid phase microextraction （HF-SLM） in environmental analysis.Hollow fiber supported liquid membrane liquid phase microextraction is a novel sample pretreatment technique developed in recent years.With inexpensive apparatus, LPME virtually uses negligible organic solvents,and combines extraction, preconcentration and sample introduction in one step.This technique has been combined with gas chromatography（GC）,high performance liquid chromatography （HPLC） and capillary electrophoresis（CE） for the analysis of non-volatile and semivolatile environmental contaminations and drugs of low concentration in various samples.This dissertation focus on developments of new models of HF-LPME for the analysis of environmental pollutants:1.A new a passive sampling device based on hollow fiber membrane-supported polypropylene glycol（PPG） was developed for sampling and determining Geosmin and 2-methylisoborneol in surface water.The material and preparation procedure for preparing the sampling device were optimized,and the effects of sampling time, sample salinity and pH on the sampling efficiency were studied.It was found that PPG 4000 exhibited high extraction selectivity and efficiency for the target Geosmin and 2-methylisoborneol.By coupling this sampling device with headspace solid-phase microextraction-GC/MS,very low detection limit（0.1 ng/L） was obtained for Geosmin and 2-methylisoborneol.This developed sampling device was successfully applied to field sampling of Geosmin and 2-methylisoborneol in Taihu lake,China.2.A simultaneously performed two/three-phase hollow fiber-based liquid-phase microextraction（HF-LPME） method was developed for the determination of aromatic amines with a wide range ofpKa（-4.25-4.6） and log Kow（0.9-2.8） in environmental water samples.The mass transfer of the analytes from the donor phase through the organic membrane phase into acceptor phase was driven by both the counter-coupled transport of hydrogen ions and the pH gradient.Afterwards,the hollow fiber was eluted with 50μL methanol to capture the analytes from both the organic membrane and the acceptor phase.The proposed procedure worked very well for real environmental water samples with microgram per liter level of analytes,and good spike recoveries（80-103%） were obtained.3.By using ionic liquid as the membrane liquid and tri-n-octylphosphine oxide （TOPO） as an additive,hollow fiber supported liquid phase microextraction （HF-LPME） was developed for the determination of five sulfonamides in environmental water samples by high performance liquid chromatography with ultraviolet detection.The extraction solvent and the parameters affecting the extraction enrichment factor such as the type and amount of the additive,pH and volume ratio of donor phase and acceptor phase,extraction time,salt-out effect and matrix effect were optimized.Under the optimal extraction conditions（organic liquid membrane phase:[C₈MIM][PF₆]with 14%TOPO（w/v）,donor phase:4 mL,pH 4.5 KH₂PO₄ with 2M Na₂SO₄,acceptor phase:25μL,pH 13 NaOH,extraction time:8 H）,low detection limits（0.1-0.4μg/L,RSD≤5%） and good linear range（1-2000 ng/mL,r²≥0.999） were obtained for all the analytes.The presence of humic acid （0-25 mg/L dissolved organic carbon） and bovine serum albumin（0-100μg/mL） had no significant effect on the extraction efficiency.Good spike recoveries over the range of 82.2-103.2%were obtained when applying the proposed method on five real environmental water samples.These results indicated that this present method was very sensitive and reliable with good repeatabilities and excellent clean-up in water samples.The proposed method confirmed hollow fiber supported ionic liquid membrane based LPME to be robust to monitoring trace levels of sulfadiazine, sulfamerazine,sulfamethazine,sulfadimethoxine and sulfamethoxazole in aqueous samples.更多还原