Spectroscopic evaluation and characterization of different historical writing inks

Systematic investigation of eight historical writing ink samples was performed using FTIR spectroscopy. The pure ingredients of inks were also analysed and the results compared to the inks themselves. The infrared spectra of all samples were recorded using three different techniques (KBr pellet, Si substrate and ZnSe cell). The KBr method was used for the characterization of evaporated to dryness ink samples, while Si substrate and ZnSe cell techniques were used for the analysis of ink aqueous solutions or suspensions. Characterization by FTIR spectroscopy revealed the specific features in historical ink samples prepared under different recipes. Therefore, FTIR spectroscopic evaluation of different ink samples provides a possibility to determine the identity of historical inks regarding their chemical composition. In addition, the evaluation of the results obtained from IR spectroscopy offers the possibility to identify effectively the nature of various ingredients in different ink samples. From all experimental results, there is a clear indication that the KBr method used for the characterization of historical writing ink samples was successful, as was the ZnSe cell technique, but the Si substrate method was unsuccessful.