Residual determination of spirotetrament and imidacloprid in onion and tomato crop by mass spectrometery

Abstract

ABSTRACT Persistence of spirotetramat and imidacloprid residues on tomato and onion after three applications of a combination formulation, spirotetramat 12% + imidacloprid 12%, @ 625 and 1250 mL ha−1 is reported. An easy and simple methodology was standardised for the extraction of residues in tomato, onion and soil followed by estimation and confirmation on LC-MS/MS using C18 column by keeping the positive mode of electrospray. The methodology was validated for selectivity, linearity, precision, repeatability, reproducibility and its limit of detection and quantification. The limit of quantification (LOQ) was worked out to be 0.05 mg kg−1. The results of recovery studies were consistent and more than 80% in all the matrices. No residues above LOQ were detected in tomato sample after 3rd day and after 7th day for onion samples.