Application of solid-phase extraction materials from ion liquids for the analysis of carbamate pesticide

In this study, ionic liquid immobilised onto silica gel material SiO2-(CH2)3-N(Oct)3Br was successfully synthesised and characterised by Fourier-transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). This material was applied as the stationary phase of solid-phase extraction for the enrichment of trace amounts of carbamate pesticides in water. The cartridge was eluted with 5 ml of acetonitrile (ACN), blow-dried with nitrogen gas, and re-dissolved in ACN:H2O (40:60, v/v) and analysed by high-performance liquid chromatography - ultraviolet (HPLC-UV) at 210 and 245 nm. Within this process, elution of the cartridge with 5 ml of acetonitrile (ACN) was followed by nitrogen gas blow-drying and subsequent re-dissolution in ACN:H2O (40:60, v/v), culminating in analysis by HPLC-UV at 210 and 245 nm. Optimisation of conditions facilitated the analysis of carbamate pesticides, with the limit of quantitation (LOQ)ranging from 0.36-2.00 μg/l for tap water and 0.4-3.5 μg/l for river water. Furthermore, the method exhibited favourable repeatability, with a relative standard deviation (RSD) of less than 10%, thereby meeting the Association of Official Analytical Collaboration (AOAC) standards.