The differentiation of commercial inks on the bases of physical and chemical analysis by the Video Spectral Comparator and Thin Layer Chromatography

Differentiating inks by chemical and physical analysis is an essential forensic step in question document investigation. This article aims to further differentiation methods by using a video spectral comparator. Inks were first subject to thin layer chromatography and observed in the video spectral comparator under normal, ultraviolet, and infrared light. Each ink was then used to write the word “Forensics” and observed under the same conditions. Finally, the inks were overlapped, and observed under the various lights to see if distinguishability was possible. Most successful under infrared light, this method allowed for differentiation between 12 of the 15 inks based on fluorescent activity