Simultaneous qualitative and quantitative determination of 104 fat-soluble synthetic dyes in foods using disperse solid-phase extraction and UHPLC-Q-Orbitrap HRMS analysis.

Abstract

Public exposure to synthetic dyes through foods has attracted ongoing and serious attention. Here we developed and validated a simultaneous screening and quantitation method for the analysis of fat-soluble synthetic dyes that most frequently found in foods, using C18 d-SPE clean-up and UHPLC-Q-Orbitrap HRMS on Full-MS/dd-MS2 mode. During a single run, 104 dyes including 6 pairs of isomers were distinguished based on chromatographic separation and unique product ions. The method showed satisfactory linearity (R>0.99), recoveries (61.3%-118.8%), precision (<20%) and limit of quantification (0.05-0.5mg/kg). For 98% of test dyes, screening detection limits ranged from 2.5 to 25μg/kg. The validated method was successfully applied to real commercial foodstuffs revealing the presence of two selected illegal dyes in three samples.