Abstract:

A simple, efficient and sensitive method for the simultaneous determination of nitrofurantoin (NFT), furazolidone (FZD) and nitrofurazone (NFZ) in feed and water samples was developed by stir bar sorptive extraction (SBSE) coupled to high performance liquid chromatography with diode array detection. The SBSE based on poly (vinylimidazole-divinylbenzene) (VIDB) monolithic material as coating was used to concentrate the three target analytes. To obtain the optimum extraction performance, several VIDB-SBSE parameters were investigated and studied, including pH value, ionic strength of sample matrix, extraction and desorption time. Under the optimized experimental conditions, the linear ranges were 0.5-200 μg/L for FZD, 0.25-200 μg/L for NFT and NFZ. The limits of detection (S/N=3) were in the range of 0.068-0.11 μg/L for the three analytes. The precision of the proposed method was evaluated in terms of intra- and inter-day repeatability calculated as RSD, and it was found that the RSDs were all below 6%. The developed method was successfully applied to the determination of nitrofuran residues in animal feed and water samples. The satisfactory recoveries of the spiked target compounds were in the range of 80.6%-108%.

Key words: feed, high performance liquid chromatography (HPLC), monolithic material, nitrofuran residues, stir bar sorptive extraction (SBSE), water samples