Flow injection chemiluminescence determination of copper oxychloride (fungicide) in freshwater and fruits samples employing 1, 10-phenanthroline—H2O2 reaction system

Abstract

A flow injection (FI) method employing the reaction between 1,10-phenanthroline (C12H8N2) and hydrogen peroxide (H2O2) in a basic medium (pH 12) with chemiluminescence (CL) detection has been developed to detect copper oxychloride pesticides in freshwater and fruit samples. The experimental conditions were optimized, and a solid phase extraction (SPE) technique modified with cupron was employed for effective phase separation during extraction. Calibration curves for copper oxychloride standard solutions demonstrated linearity over the range of 0.001 to 10 μg L−1, with the regression equation y = 506681x − 422.29 and a coefficient of determination (R 2) of 0.9973 (n = 9). The limits of detection (LOD) and quantification (LOQ) were determined to be 2.62 × 10−4 μg L−1 and 7.94 × 10−4 μg L−1, respectively. Relative standard deviations (RSDs) ranged from 2.6% to 4.5%, and the method achieved an injection throughput of 120 h−1. When applied to spiked water and fruit samples, the method showed no significant differences at the 95% confidence level compared to established methods. Recoveries for copper oxychloride were found to range from 96% to 120% (RSD = 1.9 − 5.6%) in fruit samples and from 95% to 110% (RSD = 1.5 − 4.8%) in water samples. Additionally, the potential chemiluminescence reaction mechanism was investigated.