Shanghai Key Laboratory of Functional Materials Chemistry, East China University of Science and Technology, Shanghai, PR China.
J Sep Sci. 2012 Sep;35(18):2430-7. doi: 10.1002/jssc.201200260. Epub 2012 Aug 9.
A simple and effective preconcentration method based on magnetic core-shell silica nanoparticles with C(18)-modified surface was developed for the analysis of pesticide residues in environmental water samples by gas chromatography-mass spectrometry. Several kinds of organophosphorous and pyrethroid pesticides including methamidophos, dichlorvos, orthene, phorate, dimethoate, carbofuran, bifenthrin, fenpropathrin, cypermethrin, fenvalerate, and deltamethrin were used as model compounds to systematically evaluate the method. Various parameters, including the amounts of magnetic nanoparticles absorbents, extraction time, eluting solvent, eluting volume, and sample pH values were optimized. The optimized method affords low detection limits (signal-to-noise ratio = 3) from 0.001 to 0.008 μg/L, and shows good linearity with correlation coefficients over 0.9990 in the concentration range of 0.025-0.5 μg/L. Average recoveries at three spiked levels were in the range of 70.2-110.2% with relative standard deviations below 9.6%. A maximum enrichment factor of 1015 times was achieved. Analysis results of poisoned pond water indicate that this method is fast, convenient, and efficient for the detections of low-concentration pesticides in aqueous samples.
基于 C(18)修饰表面的磁性核壳二氧化硅纳米粒子的一种简单有效的预浓缩方法，被开发用于通过气相色谱-质谱法分析环境水样中的农药残留。几种有机磷和拟除虫菊酯类农药，包括甲胺磷、敌敌畏、氧乐果、甲拌磷、乐果、涕灭威、高效氯氟氰菊酯、氯菊酯、氯氰菊酯、溴氰菊酯和溴氰菊酯，被用作模型化合物来系统地评价该方法。优化了各种参数，包括磁性纳米粒子吸附剂的用量、提取时间、洗脱溶剂、洗脱体积和样品 pH 值。优化后的方法提供了从 0.001 到 0.008μg/L 的低检测限（信噪比=3），在 0.025-0.5μg/L 的浓度范围内具有良好的线性关系，相关系数均大于 0.9990。在三个加标水平下的平均回收率在 70.2-110.2%之间，相对标准偏差低于 9.6%。最大富集因子达到 1015 倍。对中毒池塘水的分析结果表明，该方法快速、方便、高效，适用于检测水样中低浓度的农药。
