Determination of fungicides in bell pepper using solid-liquid extraction with low temperature partitioning

Abstract

A novel method based on solid-liquid extraction with low temperature partition combined with gas chromatography with electron capture detection was established for the determination and quantification of fungicides (azoxystrobin, chlorothalonil and difenoconazole) in bell pepper (Capsicum annum L.). The performance of the method was assessed by studying selectivity, limits of detection and quantification, linearity, accuracy, and precision. Linearity (r > 0.99) was achieved for all compounds when calibration was performed, and the limits of quantification were below the tolerance levels of fungicides set by Brazilian legislation, the European Union, and the Codex Alimentarius. The average recoveries ranged between 97 and 108%, with relative standard deviations ≤12.2%. The proposed analytical method has been successfully applied for the analysis of real bell peppers samples cultivated in Viçosa city, Minas Gerais State, Southeastern Brazil. The residual fungicide concentration in the bell pepper samples was azoxystrobin (0.12 ± 0.01 mg kg−1), difenoconazole (0.18 ± 0.01 mg kg−1) and chlorothalonil (1.73 ± 0.02 mg kg−1).