Determination of multiclass pesticides in river sediments via matrix solid-phase dispersion extraction and gas chromatography-tandem mass spectrometry.

Abstract

A fast and environment-friendly analytical method was implemented to determine multiclass pesticides in river sediments. Twenty-three pesticides-organochlorine pesticides, organophosphorus pesticides, and triazines-were extracted via matrix solid-phase dispersion (MSPD) and analyzed by gas chromatography-tandem mass spectrometry (GC-MS/MS). Florisil demonstrated excellent analytes uptake capability as the extractant phase, with suitable selectivity for treating complex sediment samples. Under defined extraction conditions, the MSPD-GC-MS/MS method demonstrated robustness in the n inter-day analysis of sediments from different sources, providing limit of quantifications (LOQs) between 5 and 15ng/g, linear responses in the range between LOQs and 150ng/g, extraction recoveries of 71%-106%, and precision, assessed as relative standard deviation below 20%. The MSPD significantly reduced samples and solvents' consumption, providing critical environmental gains compared to traditional extraction methods like Soxhlet. Finally, the method was applied to analyze sediment samples from three different collection areas of the Subachoque River (Cundinamarca, Colombia), demonstrating a fast, efficient, confident, and profitable analytical tool for pollution control and monitoring in environmental samples. The method allowed us to determine the current use in Colombia of banned pesticides under the 2001 Stockholm Convention.