Determination of pretilachlor in soil and rice using matrix solid-phase dispersion extraction by capillary electrophoresis with field amplified sample injection and electrochemiluminescence detection

Abstract

A novel method for pretilachlor determination by capillary electrophoresis (CE) with electrochemiluminescence (ECL) detection is proposed. Matrix solid phase dispersion was employed to extract pretilachlor from solid sample matrices and eliminate the interference from majority impurity. The field amplified sample injection technique was used to improve the sensitivity. The CE separation, ECL detection and sample pretreatment are investigated in detail. The linear range of 0.1–10 μmol L⁻¹ with a detection limit (S/N = 3) of 0.02 μmol L⁻¹ is obtained by CE-ECL with the tris(2,2-bipyridine)-ruthenium(II) (Ru(bpy)₃²⁺–ECL) system. The developed method is successfully applied for the analysis of pretilachlor residues in rice and soil samples. The average recoveries are in the ranges of 88.7–95.5% for rice, and 92.3–93.3% for soil, respectively. The limits of detection of the proposed method were 0.01 mg kg⁻¹ in rice matrix, and 0.008 mg kg⁻¹ in soil matrix, respectively.