Early synthetic textile dyes of the late 19th century from the "Primo Levi" Chemistry Museum (Rome): A multi-technique analytical investigation

In the present work a historical collection of early synthetic dyes, stored at the "Primo Levi" Chemistry Museum of the Universita La Sapienza di Roma, the so-called coloreria, was investigated through different analytical techniques: Fourier-transform Infrared (FTIR), UV-visible, Raman and surface-enhanced Raman (SERS) spectroscopies, CHN elemental analysis, electron-spray ionization mass spectrometry (ESI-MS) and X-ray diffraction (XRD). The aim was to characterise five dyes of unknown composition, produced by one of the main dye manufacturers of the 19th century, the Leopold Cassella & Co. The combination of the different methods led to the identification of the five colourants as Chrysoidine G, Amaranth, Direct Scarlet B, Acid Fuchsin and Nile Blue, and extensive bibliographic research confirmed the reliability of the hypotheses formulated on the basis of the analytical data.(c) 2022 Consiglio Nazionale delle Ricerche (CNR). Published by Elsevier Masson SAS. All rights reserved.