A Simple, reversed-phase Ultra performance liquid chromatographic method for the simultaneous determination of Monocrotophos, Thiram, carbendazim, Carbaryl and imidacloprid pesticides by Quechers method in chilli samples.

A simple, reversed-phase Ultra-performance liquid chromatographic (RP-UPLC) method for the simultaneous determination of five pesticides namely Monocrotophos, Thiram, Carbendazim, Carbaryl and Imidacloprid has been developed. This method involves sample preparation by QueCherS method and quantification by ultra performance liquid chromatography with   tunable dual wavelength detector. The mobile phase composition was varied to improve peak resolution and peak sensitivity. Choosing the match between the stationary phase and mobile phase composition, the developed RP-UPLC method not only can simplify the procedure but also significantly reduce the analysis time. The method presents an average recovery of 87.9% and 96.9%, in repeatability and intermediate precision conditions, respectively, with adequate precision (RSD from 0.8 to 20.7%), for all compounds. The method was applied to determine these pesticide residues in chilli samples

Multiresidue pesticide analysis in tomato using GC-MS/MS using modified QuEChERS method with titanium-coated graphite with CNT-ABS nanocomposite as dispersive solid-phase extraction materials

Abstract The presence of pesticide residues in food and vegetables is a growing concern for consumers. To monitor these residues reliably, a selective and sensitive multiresidue system has been developed and validated in tomato by gas chromatography–tandem mass spectrometry (GC-MS/MS). Titanium-coated graphite with carbon nanotube (CNT) in acrylonitrile–butadiene–styrene (ABS) used as reversed-dispersive solid-phase (extraction materials with modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method. Titanium-coated graphite with CNT-ABS is synthesized, characterized by X-ray diffraction and scanning electron microscopy. The clean-up performance of titanium-coated graphite with CNT-ABS was demonstrated to be better to primary secondary amine and graphitized carbon black cartridges. The processing of two multiple reaction monitoring transformations for each analyte is done using GC-MS/MS in electron impact mode. Satisfactory purification and recovery effects (74%–100%) of 35 pesticides were achieved in tomato matrices when using 5 mg of titanium-coated graphite ABS-CNT nanocomposite. It was observed that quinolphos and deltamethrin are present above the maximum residue limit. The technique proved to be reliable and sensitive in tomato samples for the routine testing of 35 pesticides.</jats:p