Toxic Pesticide Residue Analysis in Environmental Water Samples Using Silica Nanoparticles Coupled with Gas Chromatography–Mass Spectrometry

The study investigates the application of silica nanoparticles synthesized through Stöber's mechanism to enhance the adsorption capacity in pre-concentrating pesticide residues in environmental water samples. These nanoparticles, characterized by SEM, TEM, and XRD, range from 50 to 250 nm. Solid phase extraction cartridges were developed using 200 mg of nanoparticles within PTFE frits, optimized to reduce pore size for effective retention. The method evaluates the pre-concentration of pyrethroid pesticides such as transfluthrin, metofluthrin, and esbiothrin. Key parameters such as temperature, sample volume, flow rate, pH, and ionic strength were examined to optimize the adsorption process. Comparisons with commercial C18 cartridges demonstrate the method's efficacy, and separation parameters were established for simultaneous pesticide residue analysis using GC-EI-MS. The method's validation includes assessments of linearity, precision, and accuracy, with determined limits of detection and quantification. This study presents a novel approach to enhancing analytical methods for environmental monitoring of pesticide residues.