Probing the (photo)chemical stability of Emerald Green in paintings by Robert Delaunay and related historical art materials

We propose to exploit µ-XRF mapping and µ-XANES spectroscopy at S K-, Cu K- and As K-edges to perform a spatially resolved study of copper acetoarsenite (aka emerald green, EM) in paint cross-sections from artworks by Robert Delaunay (Centre Pompidou, Paris) and historical paint materials (MUNCH and Gettens Collections). Combined with the previous studies carried out on artificially aged paint mock-ups, this will permit us to elucidate degradation mechanism of EM in Delaunay’s paintings and especially how environmental agents, such as light, may have prompted the pigment’s degradation.