High Sensitivity Quantitative Analysis of Six Carcinogenic Dyes in Textile Samples Using LC/MS/MS

Synthetic dyes are commonly used in manufacturing such as the textile and leather industries. Some of these chemical dyes are known to be carcinogenic, allergenic and/or hazards. Due to potential health risks, legislations such as European Union (EU) 2002/37/EC and Oeko-Tex Standard 100 were introduced to restrict the use of some synthetic dyes in textiles. Analysis methods for detection and quantitation of synthetic dyes using HPLC and LCMS have been reported. We reported previously a MRM-based LC/MS/MS method for quantitative screening of 47 commonly-used synthetic dyes in textiles, including azodyes, disperse and basic dyes. In this study, a new LC/MS/MS method was developed for quantitative analysis of six specific carcinogenic dyes in textiles, which could not be analysed steadily by the previous method established for 47 synthetic dyes on LCMS-8040. These six dyes are Acid Red 26, Direct Red 28, Direct Black 38, Direct Blue 6, Direct Brown 95 and Basic Blue 26. The first five compounds are aromatic azodyes with two or more -SO3-Na+ groups. The Basic Blue 26 is a chloride of amine with three aromatic amine groups in the structure. Both the large molecular sizes and multi-ionic groups of the six dyes make them difficult to be analysed with a single LC/MS/MS method. We describe here a new MRM method optimized for enabling simultaneous analysis of the six dyes in textiles with high sensitivity.