A self-separating, analyte-compatible, and efficient clean-up method for QuEChERS extracts was designed and developed based on dispersive solid-phase extraction using a branched polyethylenimine and nanoscale CaSO₄ functionalized carboxylated multi-walled carbon nanotubes (MWCNTs) nanohybrids as sorbent. The feasibility of using a self-separating strategy based on the functionalization of sorbent in a purification procedure was analyzed for the first time in this study. Compared to the traditional QuEChERS method, the proposed method is rapid and convenient without centrifugation of numerous samples in the clean-up process. The use of nanohybrids overcame the issue of low recoveries for planar pesticides, which are easily adsorbed using MWCNTs. A better clean-up capability of the nanohybrids to remove matrix interferences and reduce matrix effect was demonstrated compared with that of traditional clean-up sorbent primary secondary amine. The method was validated by determining twenty-eight pesticides in cucumber, cabbage, apple, and orange. Limits of detections were in the range of 0.0001−0.0026 mg/kg. Spike recoveries of pesticides were within 75.3 − 113.6%, with relative standard deviations less than 14.3% at levels 0.01 mg/kg and 0.1 mg/kg. The developed method was successfully applied to monitor the multi-residues.

基于使用支化聚乙烯亚胺和纳米级 CaSO _{4 的}分散固相萃取，设计和开发了一种自分离、分析物兼容且高效的 QuEChERS 萃取物净化方法功能化羧化多壁碳纳米管（MWCNT）纳米杂化物作为吸附剂。本研究首次分析了在纯化过程中使用基于吸附剂功能化的自分离策略的可行性。与传统的 QuEChERS 方法相比，该方法快速方便，在净化过程中无需对大量样品进行离心。纳米杂化物的使用克服了平面农药回收率低的问题，这些农药很容易被多壁碳纳米管吸附。与传统的净化吸附剂伯仲胺相比，纳米杂化物在去除基质干扰和降低基质效应方面具有更好的净化能力。该方法通过测定黄瓜、卷心菜、苹果和橙子中的 28 种农药得到验证。检测限在 0.0001-0.0026 mg/kg 的范围内。农药的加标回收率在 75.3 - 113.6% 之间，相对标准偏差在 0.01 mg/kg 和 0.1 mg/kg 水平下小于 14.3%。所开发的方法已成功应用于多残留监测。