The Combined Use of Ion Chromatography and Scanning Electron Microscopy to Assess Salt-affected Mineral Materials in Cultural Heritage

ABSTRACT Careful sampling, sample preparation, and subsequent measurements are key steps in handling complex, salt-affected mineral materials. Chemical analyses of ionic components in aqueous solutions (ion chromatography – IC) are nearly always affected by the presence of components originating mostly from the substrate; this causes discrepancies when calculating the equivalent concentrations. This study uses IC and scanning electron microscopy (SEM-EDS) results from the investigation of two historical, salt-laden buildings from Austria to determine the influence of different mineral substrates on the inorganic ionic compositions. Results show that besides carbonate substrates, also seemingly pure salt crusts may include impurities distorting the results and thus the interpretation of data by using the ECOS Runsalt model. The combined use of IC and SEM-EDS provided a reliable solution to assess complex salt-affected building materials.