On the dehydroindigo contribution to Maya Blue

A series of data from voltammetric, spectral, and UPLC-MS and Py-GC-MS analyses of extracts from synthetic Maya Blue-type specimens provides evidence on the presence of a significant amount of dehydroindigo, identified on the basis of its MS, FTIR, and UV-Vis signatures, accompanying indigo and other minority compounds, supporting the view of this material as a complex polyfunctional organic-inorganic hybrid material. Estimates of dehydroindigo/indigo in-depth distribution and thermochemical data for the dye association to the clay from chromatographic and voltammetric data are provided.