土壤中甲胺磷、亚磷酸二甲酯和O,O-二甲基二硫代磷酰氯的同时测定

Simultaneous Determination of Methamidophos,Dimethylphosphite and Dimethyl Chlorothiophosphate in the Soil

为建立一种同时测定土壤中甲胺磷、亚磷酸二甲酯和O,O-二甲基二硫代磷酰氯的方法,采用简单的甲醇萃取,并使用液相色谱-三重四极杆质谱联用方法对萃取液进行检测,外标法定量,该方法甲胺磷、亚磷酸二甲酯和二甲基硫代磷酰氯的检出限为0.02~1.49 ng/g,达到土壤中残留量痕量检测水平。在实际土壤样品中模拟不同的农药残留水平进行低、中、高加标,基体的加标回收率范围集中在90.2%~110.5%,平行测定方法精密度RSD范围为1.18%~2.49%,回收率好并且稳定,方法精密度高。建立了高灵敏度和高重现性的检测方法,前处理简单。其中,亚磷酸二甲酯和二甲基硫代磷酰氯的检测方法较少文献报道,对于结构类似的有机磷农药或其中间体的检测具有参考价值。

In this paper,a method is developed to simultaneously determine the residues of organophosphorus pesticides as well as their intermediates and metabolites.Methanol is applied as extractant while the extract is analyzed using LC-MS/MS,and the results are quantified by external reference methods.The detection limits of this method for methamidophos,dimethylphosphite and dimethyl chlorothiophosphate fall into the range from 0.02ng/g to 1.49ng/g,which meets the standard for trace detection of soil residues.Different levels of standard solutions were added to actual soil samples to simulate low,intermediate and high residual levels,with results of recoveries achieved at a range from 90.2%to 110.5%,and the range of the relative standard deviation(RSD)of parallel determinations was 1.18%~2.49%,which indicates that the recovery rate is high and dependable and the detection method is precise.This method hence works as a simple and practical option to simultaneously detect several organophosphorus insecticides and their intermediates and metabolites with excellent sensitivity and reproducibility.There is relatively little research in available literature on the detection of dimethylphosphite and dimethyl chlorothiophosphate.Therefore,this method is of great value and can be used for reference for detecting similarly structured organophosphorus pesticides or their intermediates.