School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou, 510275, China.
Anal Chem. 2012 Jan 3;84(1):420-7. doi: 10.1021/ac202798w. Epub 2011 Dec 5.
A novel one-step sample preparation technique termed hybrid field-assisted solid-liquid-solid dispersive extraction (HF-SLSDE) was developed in this study. A simple glass system equipped with a condenser was designed as an extraction vessel. The HF-SLSDE technique was a three-phase dispersive extraction approach. Target analytes were extracted from the sample into the extraction solvent enhanced by the hybrid field. Meanwhile, the interfering components were adsorbed by dispersing sorbent. No cleanup step preceded chromatographic analysis. The efficiency of the HF-SLSDE approach was demonstrated in the determination of organochlorine pesticide (OCP) residues in tobacco with a gas chromatography-electron capture detector (GC-ECD). Various operation conditions were studied systematically. Low detection limits (0.3-1.6 μg/kg) and low quantification limits (1.0-4.5 μg/kg) were achieved under the optimized conditions. The recoveries of OCPs ranged from 70.2% to 118.2%, with relative standard deviations of <9.6%, except for the lowest fortification level. Because of the effect of the hybrid field, HF-SLSDE showed significant predominance compared with other extraction techniques. The dispersing sorbent with good cleanup ability used in this study was also found to be a microwave absorption medium, which could heat the nonpolar extraction solvent under microwave irradiation. Different microstructures of tobacco samples before and after extractions demonstrated the mechanism of HF-SLSDE was based on an explosion at the cell level. According to the results, HF-SLSDE was proved to be a simple and effective sample preparation method for the analysis of pesticide residues in solid samples and could potentially be extended to other nonpolar target analytes in a complex matrix.
本研究提出了一种新型的一步样品制备技术，称为混合场辅助固-液-固分散萃取（HF-SLSDE）。设计了一个带有冷凝器的简单玻璃系统作为萃取容器。HF-SLSDE 技术是一种三相分散萃取方法。目标分析物在混合场的增强作用下从样品中被萃取到萃取溶剂中，同时，干扰成分被分散的吸附剂吸附。在进行色谱分析之前，无需进行净化步骤。HF-SLSDE 方法在气相色谱-电子捕获检测器（GC-ECD）测定烟草中的有机氯农药（OCP）残留中得到了验证。系统研究了各种操作条件。在优化条件下，可实现低检测限（0.3-1.6μg/kg）和低定量限（1.0-4.5μg/kg）。OCP 的回收率范围为 70.2%-118.2%，相对标准偏差<9.6%，除了最低加标水平。由于混合场的作用，HF-SLSDE 与其他萃取技术相比具有显著优势。本研究中使用的具有良好净化能力的分散吸附剂也被发现是一种微波吸收介质，可在微波辐射下加热非极性萃取溶剂。萃取前后烟草样品的不同微观结构证明了 HF-SLSDE 的机制基于细胞水平的爆炸。根据结果，HF-SLSDE 被证明是一种用于分析固体样品中农药残留的简单有效的样品制备方法，并且有可能扩展到复杂基质中其他非极性目标分析物。
