Two Pathways for the Degradation of Orpiment Pigment (As₂S₃) Found in Paintings.

ABSTRACT: Paintings are complex objects containing many different chemical compounds that can react over time. The degradation of arsenic sulfide pigments causes optical changes in paintings. The main degradation product was thought to be white arsenolite (As₂O₃), but previous research also showed the abundant presence of As(V) species. In this study, we investigate the influence of the presence of a medium on the degradation mechanism of orpiment (As₂S₃) using synchrotron radiation (SR)-based tomographic transmission X-ray microscopy, SR-based micro-X-ray fluorescence, and X-ray absorption near edge structure spectroscopy. Upon direct illumination of dry orpiment powder using UV-visible light, only the formation of As₂O₃ was observed

SUBMITTER: Broers FTH 

PROVIDER: S-EPMC10141271 | biostudies-literature | 2023 Apr

REPOSITORIES: biostudies-literature