What Can Insects Tell Us about the Use of Pesticides? The Detection and Quantification of Chlorpyrifos via QuEChERS and HEADSPACE-SPME Methods Using GC/MS/MS

Abstract

The global use of pesticides, exceeding 4 million tons annually, poses substantial threats to public health and the environment. Numerous studies emphasize the correlation between pesticide exposure, genotoxicity, and neurobehavioral effects, which particularly impact children and agricultural workers. Recent research underscores the health risks associated with moderately toxic pesticides like chlorpyrifos. Chlorpyrifos contamination in crops, a result of extensive pesticide use since the 1960s, raises significant concerns regarding human health and the environment. Given its potential atmospheric volatilization from crops, alternative detection methods are imperative. This study employs gas chromatography coupled with mass spectrometry (GC/MS) in MS/MS mode, focusing on detecting chlorpyrifos in Chilean lettuce, using insects as indicators. Two extraction methods, micro-QuEChERS and HEADSPACE-SPME, were compared, with HEADSPACE-SPME demonstrating superior sensitivity (6.77 ng/mg per sample vs. 3.99 ng/mg per sample) and offering time- and solvent-saving advantages. Additionally, HEADSPACE-SPME preserves samples for future research, enhancing its utility. The study confirms the presence of pesticide residues in insects from lettuce crops, with 52.3% displaying chlorpyrifos when the SPME method was used. Predatory and parasitoid insect families like Braconidae and Ichneumonidae show high pesticide loads. The findings of this study emphasize the widespread contamination of chlorpyrifos in lettuce crop insects and highlight the efficacy of SPME for detection, suggesting its broader applicability for evaluating pesticide residues in horticultural systems. This optimized method holds promise for advancing chlorpyrifos contamination detection in agroecosystems, contributing to environmental monitoring and food security.