Dispersive microextraction based on "magnetic water" coupled to gas chromatography/mass spectrometry for the fast determination of organophosphorus pesticides in cold-pressed vegetable oils.
Dispersive microextraction based on "magnetic water" coupled to gas chromatography/mass spectrometry for the fast determination of organophosphorus pesticides in cold-pressed vegetable oils.
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DOI：
10.1021/jf400870m
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发表时间：
2013-05
影响因子：
6.1
通讯作者：
Qin Zhao;Q. Lu;Qiongwei Yu;Yuqi Feng
中科院分区：
文献类型：
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作者：
Qin Zhao;Q. Lu;Qiongwei Yu;Yuqi Feng
本文介绍了一种基于“磁水”（m-water）的分散微萃取的新应用，用于从冷榨植物油中纯化有机磷农药（甲胺磷、氧化乐果、久效磷）。在本研究中，微量的水（萃取剂）通过亲水相互作用被吸附在裸露的 Fe3O4 上，形成 m-水。当中水在剧烈涡流的帮助下分散在样品溶液中时，可以实现快速提取。萃取后，吸附了分析物的m水可以很容易地通过磁铁从样品溶液中分离出来，这可以大大简化操作并减少整个预处理时间。研究了影响提取效率的几个参数，并在优化条件下，通过气相色谱/质谱（GC/MS）联用建立了一种简单有效的农药分析方法。该方法的线性范围为2-100 ng/g，相关系数(R)为0.9997-0.9998，目标化合物的定量限(LOQ)在0.70-1.27 ng/g范围内。此外，通过评估日内和日间精密度来获得再现性，相对标准偏差 (RSD) 分别小于 7.2% 和 6.5%。最后，所建立的“磁水”微萃取方法成功应用于多种冷榨植物油中农药残留的测定。
This article presents a novel application of dispersive microextraction based on "magnetic water" (m-water) for the purification of organophosphorus pesticides (methamidophos, omethoate, monocrotophos) from cold-pressed vegetable oils. In the present study, a trace amount of water (extractant) was adsorbed on bare Fe₃O₄ by hydrophilic interaction to form m-water. Rapid extraction can be achieved while the m-water is dispersed in the sample solution with the aid of a vigorous vortex. After extraction, the analyte-adsorbed m-water can be readily isolated from the sample solution by a magnet, which could greatly simplify the operation and reduce the whole pretreatment time. Several parameters affecting the extraction efficiency were investigated, and under the optimized conditions, a simple and effective method for pesticide analysis was established by coupling with gas chromatography/mass spectrometry (GC/MS). The linearity range of the proposed method was 2-100 ng/g with satisfactory correlation coefficients (R) of 0.9997-0.9998, and the limits of quantification (LOQ) for the target compounds were in the range of 0.70-1.27 ng/g. In addition, the reproducibility was obtained by evaluating the intra- and interday precisions with relative standard deviations (RSDs) less than 7.2% and 6.5%, respectively. Finally, the established "magnetic water" microextraction method was successfully applied for the determination of pesticide residues in several kinds of cold-pressed vegetable oils.