Page - 105 - in The Vienna Genesis - Material analysis and conservation of a Late Antique illuminated manuscript on purple parchment

Maurizio Aceto, Maria João Melo, Elisa Calà, Paula Nabais, Rita Araújo 105 the purple colour of the parchment. The following analysis enabled the production of a fingerprint identification of the dye. For the study, four techniques were selected. UV-visible diffuse reflectance spectropho- tometry with optic fibres (FORS) was used for the preliminary identification of the dye. Spectrofluorimetry yielded complementary information. Micro-spectrofluorimetry on aged reference samples and on original parchment micro-samples enabled further insight Table 1b: Possible sources for purple dyeing in antiquity and molecular structures for the main chromophores: Chrozophora tinctoria and shellfish purple (Hexaplex trunculus). Dyed parchment samples were irradiated with a Xenon lamp (lirr ≥ 320 nm), photographs and L*a*b* colour coordinates for unaged and 310 h irradiation are given. Fig. 1: Structure of dibromoin- digotine. Open-Access-Publikation im Sinne der CC-Lizenz BY 4.0