Simultaneous Detection Method for Mycotoxins and their Metabolites in Animal Urine by Using Impurity Adsorption Purification followed by Liquid Chromatography-Tandem Mass Detection

Abstract

A novel method for simultaneous detection of mycotoxins (e.g., aflatoxin B1) or their metabolic residues in animal urine with impurity adsorption purification followed ultra-performance liquid chromatography coupled tandem mass spectrometry (UPLC-MS/MS) detection has been developed. Extraction of mycotoxins or their metabolites in animal urine sample was performed with 0.1% formic acid-acetonitrile solution after addition of sodium chloride. The extract was then dehydrated and purified with hydrous magnesium sulfate, C18, primary secondary amine, and alumina-A. 3 mL of the supernatant was evaporated and re-dissolved by 0.5 mL of 0.1% formic acid aqueous solution/ acetonitrile (70:30, V/V) for UPLC-MS/MS detection. A C18 reversed-phase chromatographic column was employed for separation of target analytes. In the chromatographic separation of target analytes, 0.1% formic acid aqueous solution and 0.1% formic acid-methanol solution were used as the mobile phases with the optimum gradient elution procedures. Multiple-reaction monitoring (MRM) mode was applied for qualitative and quantitative analysis, and matrix calibration curves obtained with the external-standard method was used for quantitation of target analytes. Under optimized conditions, the linearity range was 0.05-100 ng/mL, and the limit of quantification of the developed method was 0.05-0.25 ng/mL. The recoveries of mycotoxins and their metabolites spiked in urine samples were from 80.8% to 114.3%, and the relative standard deviation was <15%.