Analytical approaches for the characterization of early synthetic organic pigments for artists’ paints

Several analytical techniques have shown use for the identification of historical synthetic organic pigments (SOPs) in samples. However, as differ—for example, extent sample intervention, modes detection, and limits detection—so do they differ results insights into colorants colorant derivatives a sample. Liquid chromatography (LC) is infrequently applied to task SOP identification, despite its ability differentiate similar molecules, detect at low concentrations, separate complex samples established usage dyes. This research compared obtained with micro-Raman spectroscopy pyrolysis gas from ultra-high performance (UP)LC coupled photodiode array detection (UPLC-PDA), high resolution mass spectrometry (UPLC-HRMS) judge quantity quality information by each technique. In this study, 67 were analyzed books (1918–1950), consisting 10 oil paint tubes, 45 oil-bound paint-outs, 13 gum-bound pigment washes using sizes less than milligram. As few studies used LC special attention also paid issues around preparation interpretation UPLC-PDA UPLC-PDA-HRMS results. Finally, archival sources other contemporary documents are contextualize evaluate plausibility The indicate that specific combinations required confident identifications. While Raman accurate independent solubility, relied heavily on database completeness not sensitive mixtures or differences relative amounts SOPs. was an effective complement these shortcomings, except insoluble. HRMS critical elucidation unknown