Differentiation of Red and Black Ballpoint Pen Inks using High Performance Thin Layer Chromatography and Gas Chromatography-Mass Spectrometry

Abstract

The present study aims to distinguish the blue, black, red and green gel pen inks on the basis of their chemical constituents using High Performance Thin Layer Chromatography (HPTLC) and Gas Chromatography-Mass Spectrometry (GC-MS). HPTLC found suitable for studying dye base gel pen inks whereas GC-MS was used for both pigment and dye based gel pen inks. Interpretation of results was done on the basis of major components followed by minor components present in an ink sample. Maximum differentiation was achieved by the minor components as compared to major components. The results obtained from GC-MS were found to be more discriminating than HPTLC. Excellent differentiation was achieved within pens from the models of same make. The major advantage of present study is the limited damage caused to the document. The methodology adopted in present study could be applied in the alteration cases in the suspected documents.