Identification of unknown colorants in pre-Columbian textiles dyed with American cochineal (Dactylopius coccus Costa) using high-performance liquid chromatography and tandem mass spectrometry

• DOI: 10.1007/s00216-014-8107-y
• Publication Date: 2014-09-11T03:25:32Z
• Authors: Katarzyna Lech; Katarzyna Witkoś; Beata Wileńska; Maciej Jarosz
• Keywords: Moiety

The present study concerns the identification of nine thus-far unknown derivatives carminic acid extracted from pre-Columbian Peruvian textiles dyed with American cochineal-these are not found in commercially available preparations dye. These compounds probably represent a unique fingerprint this region, as they have never been reported to occur other fabrics historical value. They were separated by reversed-phase high-performance liquid chromatography (phenyl column) and detected using UV/vis spectrophotometer two tandem mass spectrometers. Peaks observed chromatograms registered at 450 500 nm further identified ESI QqQ MS (mainly negative ion mode), supported high-resolution QIT/ToF data. characteristic fragmentation pathways isolated its provided additional information concerning lost neutrals thus functional groups substituents parent molecules. This mainly related multiple cleavages hexoside moiety (initially cross-ring cleavage), which C-glucosides (loss 90, 120, 148 Da). is accompanied elimination H2O well loss 60 Da moiety. Moreover, losses carbonyl (44 CO2 loss, 62 ethylene glycol 32 O2 138 hydroxybenzoic acid, 120 oxomethylene cyclohexadienone) more specific about structures acid.