Quantitative determination of 58 aromatic amines and positional isomers in textiles by high-performance liquid chromatography with electrospray ionization tandem mass spectrometry.

A straightforward method for simultaneous determination of 58 aromatic amines (AAs) in clothing textiles is described. Of the tested amines, 22 are known carcinogens and regulated under European law. Further unregulated amines, which are suspected to be carcinogenic or mutagenic, are also expected to occur in textiles. The focus of this study was to obtain a multimethod with regulated and unregulated AAs and to separate different positional isomers of specific amines. To achieve this goal, the HPLC parameters such as column phase chemistry and mobile phase pH were optimized. All other amines were separated with the same conditions evaluated for the positional isomers. The sample preparation was reduced to a minimum in accordance to DIN EN 14362-1. After reductive cleavage and dilution of the extracts, the samples were prepared for LC-MS/MS analysis. Further cleanup of the samples with diatomaceous earth was no longer required with this modified sample preparation. The method was validated by spiking the extracts of blank textiles with the chosen amines. Lower Limits of Quantification (LLOQs) ranged from 1 to 10 mg kg-1. Excellent linearity from 10 to 500 µg L-1 was obtained with coefficients (r) higher than 0.99 allowing a one-point calibration (300 µg L-1 corresponding to 60 mg kg-1 in textiles) forced through zero for the samples. Recovery ranged from 88 to 116% with intra- and inter-day precision values of 1.8-12.1%. The accuracy of this method was tested by a certified reference material (iis18A03, Institute for laboratory Studies, the Netherlands) and showed excellent recoveries higher than 95%. Finally, the described method was successfully applied on 150 real samples with different textile fibres and colours. Positive results were confirmed by means of the spectral library and with the ion ratios.