Determination of banned AZO colourants in dyed textiles by liquid chromatography-electrospray ionization mass spectrometry

A method has been developed for the determination of the banned AZO colourants in dyed pure worsted fabrics by high-performance liquid chromatography coupled with an electrospray ionization mass spectrometry(HPLC-ESI/MS).After the banned AZO colourants in dyed worsted fabrics were extracted and deoxidized,the separation was performed on a ZORBAX Eclipse XDB-C18 column(150 mm × 2.1 mm I.D.,5 μm)with mobile phase consisting of 5 mmol/L aqueous ammonium acetate-acetic acid /methanol in gradient elution.Detection was carried out by an ion trap mass spectrograph with an ESI interface in the positive mode using external standard method.Simultaneous separation and determination of 21 aromatic amines were realized.The recoveries were between 80.0% ～ 102.4 %,and the RSDs were less than 9.4%.This method was found to be sensitive,fast and accurate,and it can be used for the determination of the banned AZO colourants in dyed textiles samples.