Abstract:
Forensic analysis of writing ink ageing on document is one of the most challenging parts in forensic
investigation. It can significantly prove to be useful in forensic document examination as it helps to build
a timeline of an event or provide link to investigation. The objective of this study was to study the effect
of ageing to gel pen ink on different papers i.e. A4, envelop, newspaper and manila card using Attenuated Reflectant Mode Fourier Transform Infrared (ATR-FTIR) spectroscopy. Inks were deposited on four different types of papers and subsequently subjected to ageing at different interval (7, 14, 30, 60 and 90 days). The aged and fresh inks were compared through visual examination and statistical evaluation using paired t-test was then carried out based on their mean absorbance. The results showed that the gel pen ink deposited on different types of papers subjected to ageing could not be differentiated from their fresh counterpart using ATR-FTIR and statistical analysis. As a conclusion, under the experimental parameters used in this study, the writing inks deposited on different types of papers subjected to ageing could not be differentiated from their fresh counterpart using ATR-FTIR andstatistical analysis.
