Quantitative Screening of Twenty Six Aromatic Amines Originated from Azo Dyes by LC/MS Method

Introduction

Azo dyes are synthetic organic colorants that contain at least one azo group (-N=N-) in the chemical structure. Azo dyes are widely used in the textile and leather industries for the outstanding color fastness and wide spectrum. However, they may undergo cleavage reaction under reductive conditions and, as a result, release aromatic amines if the azo group bonding with aromatic species. Many aromatic amines are known to be carcinogenic to humans. The European Union (EU) started new regulation on the use of azo dyes in consumer goods in Sep 2003, prohibiting the use of those azo dyes which can break down to release aromatic amines. A total of 22 aromatic amines from azo dyes had been listed in the Annex I of Directive 2002/61/EC. There are two analytical approaches: direct analysis of the banned azo dyes and indirect analysis of the listed aromatic amines produced from azo dyes under reductive conditions. The EU directives also set a limit of 30 ppm for each of the 22 aromatic amines in the final articles or parts when analyzed according to the official methods. This application news reports a quantitative screening method targeted for 26 aromatic amines using simultaneous SIM/scan modes on Shimadzu ultra fast LCMS-2020. However, sample pretreatment to convert azo dyes to amines was not included.

June 6, 2014 GMT