Magnetic Solid-Phase Extraction (MSPE) Using Magnetite-Based Core-Shell Nanoparticles with Silica Network (SiO2) Coupled with GC-MS/MS Analysis for Determination of Multiclass Pesticides in Water

Abstract

Abstract Background For the analysis of pesticide residues in water samples, various extraction techniques are available. However, liquid–liquid extraction (LLE) and solid-phase extraction (SPE) are most commonly used. LLE and SPE extraction techniques each have their own disadvantages. Objective The aim of the study was to develop an environment-friendly multi-residue method for determination of multiclass pesticides in environmental water samples (ground water, agricultural field/irrigation run-off water, etc.). Methods The magnetic solid-phase extraction (MSPE) technique using surface-fabricated magnetic nano-particles was used for extraction of water samples, followed by quantification by gas chromatography tandem mass spectrometry. The developed multi-residue method was validated in terms of linearity, LOD, LOQ, recovery, and repeatability. Results Recovery data were obtained at the spiking concentration level of 1, 5, and 10 µg/L, yielding recoveries in the range of 70–120%. Overall, non-polar pesticides from all the groups, i.e., synthetic pyrethroid, organophosphorus, organochlorine, herbicides, and fungicides, show acceptable recovery percentages. Good linearity (r2 value ≥ 0.99) was observed at the concentration range of 0.5–100 µg/L. RSD values were found ≤ 18.8. Conclusions The study shows that the method is specific, rapid, and low cost, as well as having a good linearity and recovery; thus, this method is applied in routine purposes for the analysis of pesticide residue in real water samples. Highlights Due to better adsorption ability, permeability, and magnetic separability, the functionalized nano-particles were found effective in the enrichment of 22 multiclass pesticides including organo-phosphorus, organo-chlorine, synthetic pyrethroid, herbicides, and fungicides.