Chemical Structure Analysis for Azo Type Disperse Dyes by Mass Spectroscopy and Detection of Dyestuff in Textile Products Causing Allergic Contact Dermatitis

Abstract

Azo-type disperse dyes are considered to be one of the causative agents of the allergic contact dermatitis caused by textile products. It was difficult to identify disperse dyes dyed in textile products, because of a large variety of them. We measured the mass spectra of disperse dyes known to be allergenic. In addition, we developed a method for determining the chemical structures of azo-type disperse dyes that have specific chemical structures for dyeing and coloring by the mass spectra. The developed method was applied to eight cases of textile products causing allergic contact dermatitis. The dyed disperse dyes were purified by high-performance liquid chromatography (HPLC), and the mass spectra were obtained using a direct probe. These results showed that dyes unrecognized as sensitizing disperse dyes develop allergic contact dermatitis. Our study suggests that this method is effective to identify those disperse dyes that cause allergic contact dermatitis.