Simultaneous Determination of Imidacloprid and Its Metabolites in Cotton and Soil

Abstract

An easy, simple and efficient analytical method for the estimation of residues of imidacloprid and its metabolites like 6-chloronicotinic acid (6-CNA), nitroguanidine, olefin, nitrosamine, urea and 5-hydroxy, in different fractions of cotton comprising cotton leaves, lint, oil, seed cake and soil is reported. Sample preparation consisted of extraction of residues from matrices using acetonitrile followed by clean up by dispersive solid phase tube. The residues were estimated using high performance liquid chromatograph (HPLC) equipped with PDA detector system, C18 column and confirmed by Liquid Chromatograph Tandem Mass Spectrometry (LC-MS/MS). HPLC grade acetonitrile: water (30: 70) was used as mobile phase @ 0.3 mL min−1. The recoveries of imidacloprid and its metabolites spiked at 0.01, 0.05 and 0.1μg g−1 levels were in the range of 80 to 94 per cent. The limit of quantification (LOQ) of the method was worked out to be 0.01 mg kg−1. The analytical method was validated in terms of parameters including selectivity, linearity, repeatability, reproducibility and accuracy.