Abstract

                                A simple, sensitive and inexpensive analytical method was developed using solid-phase extraction for the simultaneous determination of five neonicotinoid insecticides in soil matrix using LC-MS/ MS and validated. The samples were extracted with acetonitrile and subsequent cleanup was done by dispersive solid-phase extraction (QuEChERS method). The quantification was carried out by liquid chromatography-tandem mass spectrometry with electrospray ionization source (LC-ESI-MS/MS). After the optimization of the extraction parameters, the method was validated by evaluating, linearity, limits of detection and quantification, precision (repeatability) and accuracy (recovery). Validation was based on analysis at three fortification levels and showed satisfactory recoveries (77.03 to 115.08 %) and high precision (RSDs between 2.01 to 13.83%). Low limits of detection and quantification could be achieved for all the five analytes ranging from 0.0007 to 0.002 and 0.002 to 0.008 μg/g, respectively. The developed method was applied to the analyses of neonicotinoid residues in soil from sugarcane field and pot soil.

Key words : Neonicotinoid insecticides, Multi-residue analysis, Soil, LC/MS/MS.