Differential determination of cinnabar ink by multivariate analysis

Abstract

Thirteen samples of office cinnabar ink made in Japan were measured for the differential determination by microscope photometry. The method was as follows. Each sample was magnified by 50 times and the absorbance values were measured from 380 to 760 nm in 5 nm intervals by a microscope photometer. Each absorbance in a sample was divided by the absorbance at 380 nm. The obtained data of each sample were used for a calculation in a multivariate analysis, such as a cluster analysis, a principal-component analysis, KNN, and SIMCA. A classification of 13 different office cinnabar inks could be made using the cluster analysis, KNN and SIMCA.