Identification of early synthetic dyes in historical Chinese textiles of the late nineteenth century by high-performance liquid chromatography coupled with diode array detection and mass spectrometry

In the present study, five classes of synthetic dyes - nitrophenol (picric acid), azo (Orange II), diarylmethane (auramine O), triarylmethine (fuchsine, methyl violet, and malachite green), and anthraquinone (alizarin) dyes - were identified in late-nineteenth-century textiles from the China National Silk Museum by high-performance liquid chromatography coupled with diode array detection and mass spectrometry. Data-dependent acquisition of tandem mass spectra provided some information not only on the molecular mass but also on the fragment ions obtained from precursor ions. These fragmentation patterns, obtained in a single experiment, proved to be useful for identification of the synthetic dyes extracted from the textile samples. In addition, it is worth noting that two anthraquinones, which are probably anthrapurpurin and flavopurpurin, and which were detected in printed cotton, can be used as the markers for distinguishing synthetic alizarin from natural alizarin.