Determination of Carbendazim in Food Products Using a Sequential Injection Analysis Optosensor

Carbendazim (CBZ) is a widely used broad-spectrum benzimidazole fungicide used to control plant diseases in cereals, vegetables, and fruits. It has been recently found that it is useful for the control of aflatoxin contamination in chili peppers (Capsicum annuum). In addition, it is useful against other diseases in peppers and tomatoes (Solanum lycopersicum). A flow-through optosensor using C₁₈ silica gel as solid support is here presented for the fluorimetric (λ _exc/λ _em?=?276/306) determination of CBZ in Capsicum powder and dried tomatoes. The proposed system has been developed using sequential injection analysis, so improving the repeatability and automation of the system and minimizing wastes generation. The method presents a detection limit of 3 μg?L^?1, a sample throughput of 16 samples per hour and interday relative standard deviation lower than 6 %. Taking into account that the maximum residue limit specified in the Codex Alimentarius for dried peppers is 20 mg?kg^?1, recovery experiments have been carried out for CBZ concentrations in the 15–40 mg?kg^?1 range, obtaining satisfactory results. Therefore, the proposed method fulfills the current legislation and could be used as an alternative to other analytical methods, such as chromatographic ones.