Chromatographic analysis is carried out using three systems: a liquid phase high performance chromatographer (CLHP, see photo), a gaseous phase chromatographer (CPG) and an ionic chromatographer. The first two pieces of equipment enable the separation of the components that constitute the organic matter of the works of art: binders, colouring agents, fixing agents, consolidating agents, etc. They also enable the identification and the quantification of the components that are thus separated. The treatment of the data obtained thus leads to the identification of the origin of the organic material. The ionic chromatographic system is dedicated to the identification and the quantification of soluble salts extracted from the masonry.