A sensitive and efficient procedure for the high throughput determination of banned aromatic amines in textiles and leather products aided by advanced sample composition

A highly sensitive procedure for the efficient routine control of aromatic amines derived from banned azo dyes in textile and leather products was developed and optimized. The procedure involves the extraction and reduction of azo dyes from solid samples following the sample preparation protocols outlined in EN 14362-1:2003, EN 14362-2:2003, and ISO/TS 17234:2003 standards, and cleanup and concentration of aromatic amines by solid-phase extraction, with Oasis HLB and ENVI-Carb sorbents in series. The elution was carried out with the cartridges connected in series, although the positions of the cartridges were reversed and the ENVI-Carb cartridge was placed in the backflush mode. Extracted and concentrated aromatic amines were separated and analyzed by liquid chromatography (LC)-tandem mass spectrometry (MS). The chromatographic separation was optimized by means of computer-assisted method development with a special chemometric tool (the PREGA LC-MS module), developed specifically for LC-MS systems. This system enables the unattended optimization of separations after a few priming isocratic and gradient experiments. The optimized separation program enables accurate detection and measurement of all the 23 aromatic amines considered, at very low quantification limits and without any notable matrix effects. Strategic sample composition was applied as an efficient means of reducing the costs and work involved in the control of aromatic amines in finished textile and leather products. The benefits of strategic sample composition are demonstrated by means of a case study of 20 sample specimens.