Determination of 4-Aminoazobenzene in Paper Packaging by Liquid Chromatography Tandem Mass Spectrometry Combining with Liquid-Liquid Extraction and Dispersive Solid-Phase Extraction

A liquid chromatography-tandem mass spectrometric(LC-MS/MS), method for the quick detection of 4-Aminoazobenzene released from azo dyes in food wrappers, has been established. Sodium dithionite was added to sodium hydroxide solution to reduce and decompose the possible azo dyes. The extract was analyzed by liquid chromatography with tandem mass chromatography for the quantification and confirmation after a liquid-liquid extraction and dispersive solid-phase extraction. The chromatographic separations were performed on a ZORBAX Eclipse XDB-C18 column with gradient elution. In this method the conditions of chromatographic separation, mass spectrum, liquid-liquid extraction and dispersive solid-phase extraction were optimized. The detection limit was 0.13 mg/kg and the quantification limit was 0.42 mg/kg under optimal conditions, the spiking standard recoveries were ranged from 90%~95% with relative standard deviations (RSDs)≤5%.