以乙二胺-N-丙基硅烷(PSA)为吸附剂,乙腈为萃取溶剂,建立新型的基质分散固相萃取农残样品前处理技术,实现样品快速制备;利用LC-MS同时定量蔬菜和水果中的氨基甲酸酯和有机磷农药,并与常用固相萃取吸附剂ODS进行对比.选取4种代表性的蔬菜和水果,采用加标回收的方法,测定回收率和精密度,检验该方法的准确性和可靠性.对于绝大多数农药,在不同基质中,回收率为80%~110%,精密度为0.3%~8.0%.以西红柿为基质,检出限可达0.5~35 μg/kg.研究表明,本方法法简单、快速、经济并具有较高灵敏度.采用本方法可对当地市场上常见时令蔬菜及水果进行监测.
A liquid chromatography-mass spectrometry (LC-MS) method was established for the simultaneous determination of carbamate and organophosphorus pesticides (OPPs) in fruits and vegetables by dispersive solid phase extraction using acetonitrile as extraction solvent and primary secondary amine (PSA) as sorbent instead of octadecyl bonded silica (ODS). Four common representative samples ( tomato, apple, carrot and cabbage) were selected from the supermarket in order to validate the method by recovery and precision. The obtained recoveries were, with a few exceptions, in the range of 80% - 110% with RSDs less than 8% ; and limits of detection ranged from 0.5 to 35μg/kg in tomato. In addition, the method was applied to pesticides residue detection in vegetables and fruits obtained from local markets.