Flow injection chemiluminescence determination of acetochlor and cartap‐HCl in freshwater samples using an acidic KMnO4–rhodamine‐B reaction system

Abstract

AbstractA flow injection (FI) methodology using the acidic potassium permanganate (KMnO4)–rhodamine‐B (Rh‐B) reaction with chemiluminescence (CL) detection was established to determine acetochlor and cartap‐HCl pesticides in freshwater samples. Experimental parameters were optimized, and Chelex‐100 cationic exchanger mini column and solid‐phase extraction (SPE) were used as phase separation techniques. Linear calibration curves were observed for the standard solutions of acetochlor and cartap‐HCl over the ranges 0.005–2.0 mg L−1 [y = 1155.8x + 57.551, R2 = 0.9999 (n = 8)] and 0.005–1.0 mg L−1 [y = 979.76x + 14.491, R2 = 0.9998 (n = 8)] with LODs and LOQs of 7.5 × 10−4 and 8.0 × 10−4 mg L−1 (3σ blank) and 2.5 × 10−3 and 2.7 × 10−3 mg L−1 (10σ blank), respectively, with an injection throughput of 140 h−1. These methods were used to estimate acetochlor and cartap‐HCl with or without the SPE procedure, respectively, in spiked freshwater samples. Results obtained were not significantly different at a 95% confidence level to those of other reported methods. Recoveries for acetochlor and cartap‐HCl were obtained over the ranges 93–112% (RSD = 1.9–3.6%) and 98–109% (RSD = 1.7–3.8%), respectively. The most probable CL reaction mechanism was explored.