| Summary: | This study focuses on the extraction of organochlorine pesticides (OCPs) contained in environmental water samples by using encapsulated alginate-silica (Alg-SiO2) composite beads. The composite beads were made by ionic crosslinking interaction between polymeric alginate and silica particles derived from oil palm fronds and were characterized by ATR-FTIR, FESEM, and EDX to study their chemical and physical properties. The Alg-SiO2 composite beads were then used as the sorbent material for the micro-solid phase extraction (μ-SPE) to extract OCPs from aqueous samples. Optimization of method development for extraction of targeted analytes (heptachlor, aldrin, and dieldrin) was done by varying the extraction time, extraction solvent, desorption time, and sorbent mass before the gas chromatography-mass spectrometry analysis. Analytical figures of merit for μ-SPE were calculated under the optimized extraction conditions. Under the optimum conditions of 50 mg of sorbent extracted for 5 mins and desorbed using n-hexane for 7 mins, good linearity was achieved based on the data from method validation, linear ranges of 1–10 mg/L for heptachlor, 0.1–1.0 mg/L for aldrin, and 0.2–1.4 mg/L for dieldrin, with a limit of detection of 0.09–0.85 mg/L. The proposed method was successfully applied to determine organochlorine pesticides in paddy water samples. The wide range of the calibration curves was linear, and the coefficients of regression were all around 0.979-0.993. The recoveries were obtained in a satisfactory range of 82-98%, and the precision RSD value was in the range of 0.19-4.52%. © 2024, Malaysian Society of Analytical Sciences. All rights reserved.
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