Determination of Niclosamide in Aquatic Animal Tissue by a Novel Extraction Procedure and High-Performance Liquid Chromatography-Heated Electrospray Ionization-Tandem Mass Spectrometry

Niclosamide is a mollusicide used for aquaculture on a large scale in China. However, it has high toxicity to aquatic animals and may cause damage to DNA. A modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) extraction procedure with high-performance liquid chromatography-heated electrospray ionization-tandem mass spectrometry method was developed for its determination. Samples were extracted with ammoniated acetonitrile, and anhydrous magnesium sulfate was added to remove moisture and precipitate proteins. The extracts were further purified with octadecylsilane. The recoveries of niclosamide in fortified muscle tissue at concentrations of 0.5 to 20 mu g/kg were between 76.40% and 95.60% with relative standard deviations less than 9.54%. The limits of detection and quantification were 0.2 mu g/kg and 0.5 mu g/kg, respectively. The developed method was used to study the adsorption of niclosamide in channel catfish after administration.