色谱

色谱 ›› 2013, Vol. 31 ›› Issue (11): 1076-1080.DOI: 10.3724/SP.J.1123.2013.06008

• 研究论文 • 上一篇    下一篇

溶剂去乳化-悬浮固化分散液液微萃取-气相色谱-质谱联用测定水中的有机氯农药

王宇, 朱成华, 邹晓莉, 黄黎志, 严冬   

  1. 四川大学华西公共卫生学院, 食品安全监测与风险评估四川省重点实验室, 四川 成都 610041
  • 收稿日期:2013-06-04 修回日期:2013-07-11 出版日期:2013-11-28 发布日期:2013-12-05
  • 通讯作者: 邹晓莉
  • 基金资助:

    四川大学本科科研训练项目(20131462,504).

Solvent demulsification-dispersive liquid-liquid microextraction based on solidification of floating organic drop coupled with gas chromatography-mass spectrometry for simultaneous determination of organochlorine pesticides in aqueous samples

WANG Yu, ZHU Chenghua, ZOU Xiaoli, HUANG Lizhi, YAN Dong   

  1. West China School of Public Health, Sichuan University, Key Laboratory of Food Safety Risk Assessment and Monitoring of Sichuan Province, Chengdu 610041, China
  • Received:2013-06-04 Revised:2013-07-11 Online:2013-11-28 Published:2013-12-05

PDF

211

被引次数

16

摘要：

建立了溶剂去乳化-悬浮固化分散液液微萃取技术结合气相色谱-质谱联用技术同时测定水样中8种有机氯农药的方法。以正十六烷作为萃取剂,将其与分散剂丙酮混合后,快速注入水样,获得乳化体系并完成萃取;然后加入丙酮作为去乳化剂破坏乳化体系,不需要经过离心即能使两相分层;经冰浴冷冻使其固化后,取出上层凝固的有机相(正十六烷)在室温下融化,取上清液进行GC-MS分析。考察了萃取剂、分散剂、去乳化剂的种类和体积,水样盐浓度和pH值对萃取效率的影响。结果表明,8种有机氯农药在0.025~2.00 μg/L范围内有良好的线性关系(r=0.9995~0.9999), 8种有机氯农药的检出限为0.012~0.024 μg/L,精密度为3.15%~4.53%,富集倍数为96~101。将该方法应用于农田池塘水的测定,加标回收率为96.77%~102.93%,精密度为2.68%~4.86%。方法快速灵敏,有机溶剂消耗少,对环境友好,操作简便,适用于水中有机氯农药的批量分析,并为实现其样品前处理的自动化提供了技术和方法学的支持。

关键词: 气相色谱-质谱, 溶剂去乳化, 水样, 悬浮固化分散液液微萃取, 有机氯农药

Abstract:

A novel method for simultaneous determination of eight organochlorine pesticides in aqueous samples by solvent demulsification-dispersive liquid-liquid microextraction based on solidification of floating organic drop coupled with gas chromatography-mass spectrometry (GC-MS) was established. A mixture of extractant (n-hexadecane) and dispersive agent (acetone) at the ratio of 1/5 (v/v) was injected into aqueous sample to form an emulsion and an extraction process was accomplished. The demulsifier (750 μ L acetone) was then injected to break up the emulsion. The two phases were separated quickly without centrifugation. After being solidified in an ice-bath, the upper layer (n-hexadecane) was transferred into an Eppendorf tube and analyzed by GC-MS after melted at room temperature. Factors affecting extraction efficiency such as the type and volume of extractant, dispersive agent and demulsifier, also ionic strength and pH value of extraction system were studied. Under the optimized conditions, the working curve of the proposed method provided a good linearity in the range of 0.025-2.00 μg/L (r=0.9995-0.9999). The detection limits of the organochlorine pesticides calculated by Hubaux-Vos method were 0.012-0.024 μg/L and the relative standard deviations (RSDs) ranged from 3.15% to 4.53%. The enrichment factors (EF) were 96-101. When the method was applied to the determination of farmland water, the average spiked recoveries were 96.77%-102.93% with the relative standard deviations of 2.68%-4.86%. The proposed method is sensitive and fast. It also has the advantage of little organic solvent consumption so that it is friendly to environment and suitable for batch analysis of organochlorine pesticides in aqueous samples. Meanwhile, it provides technical and methodological support for achieving the automation of sample pretreatment.

Key words: aqueous sample, dispersive liquid-liquid microextraction based on solidification of floating organic drop, gas chromatography-mass spectrometry (GC-MS), organochlorine pesticides, solvent demulsification

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