Trace Level Quantification of Organophosphorus Pesticides from Fleshy Fruit Samples by Magnetic Solid-phase Extraction Using Fabricated SBA-15/Fe3O4 Coupled with HPLC/UV

A mesoporous silica SBA-15/iron oxide (Fe3O4-SBA-15) nanocomposite was fabricated and employed as a magnetic solid-phase extraction (MSPE) sorbent to determine three types of organophosphorus pesticides (OPPs) in fruit samples. The fabricated nanocomposite was analysed using high-performance liquid chromatography with an ultraviolet detector (HPLC-UV). Meanwhile, the optimisation of extraction efficiency on three OPPs analyses used three different parameters, viz. desorption conditions, extraction time, and sorbent amount. The experimental results showed that the Fe3O4-SBA-15 nanocomposite achieved high analyte recoveries ranging from 89 to 118% with a relative deviation of less than 8.0%. By combining the optimised MSPE conditions with HPLC-UV, a suitable method for determining three OPPs was developed. This study revealed that the proposed method exhibits good coefficients of determination varying from 0.9942 to 0.9980, with low limit detection (LODs) ranging from 0.03 - 0.08 mgL-1 and low limit quantifications (LOQs) of 0.10 - 0.24 mgL-1. Based on these findings, the fabricated Fe3O4-SBA-15 nanocomposite is a suitable sorbent with excellent adsorption capacity for the selected OPPs from fruit matrices.