Improved chromatographic performance in red chilli powder pesticide residue quantitation by retention gap introduction in gas chromatography tandem mass spectrometry

Abstract

Analysis of agrochemical residues in red chilli powder is always considered difficult because of higher matrix interference due to carotenoid pigments and other co-extractives. During the sample preparation, matrix components were co-extracted along with the target compounds leading to frequent source cleaning, changing of liner and column. Efforts were made to improve the chromatographic performance by optimizing sample preparation, choosing matrix-free transitions and introducing a retention gap. The Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) extraction was experimented using different dispersive adsorbents and the purified extract was analyzed by gas chromatography tandem mass spectrometry (GC–MS/MS) system. 84 pesticides under different class were validated and established a limit of quantification of 0.002–0.007 mgkg−1. The recovery was between 70 and 110% at 0.01, 0.025 and 0.05 mgkg−1 fortification level and corresponding precision was between 3 and 16% RSD. Suitability of the validated method was established through analysis of market samples of chilli powder for the quantitation of targeted pesticide residues.