Determination Of Quinoid Niclosamide (LDS) In Water, Soil And Rice Samples By QuEChERS Extraction With Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

A sensitive,rapid and easy analytical method was developed for the determination of Quinoid niclosamide（LDS）molluscicide in water,rice and soil using QuEC hERS extraction procedure with ultra-performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）detection method.The LDS was extracted using acetonitrile and then cleaned up using dispersive solid-phase extraction with florisil and C18 sorbents.The determination of the target compound was achieved in less than 3 minutes using an electrospray ionization source in negative mode.The overall average recoveries for this method in water,rice,and soil matrix at three fortified levels ranged from 82.54%to99.9%with relative standard deviations in the range of 1.51%to 4.86%（n=5）.The calculated limits of detection were lower than 0.11μgkg^-1 and quantification was 5μgkg^-1,which were much lower than the maximum residue levels established by Australian standard（0.01 mg/kg）.The results of the method validation confirmed that this proposed method is convenient and reliable for the determination of LDS molluscicide in water,rice and soil samples.This study provides a theoretical basis for China to draw up maximum residue level and analytical method for LDS in different agricultural and environmental commodities.