Discrimination of Blue and Black Ballpoint Pens’ Ink and Its Effectiveness in Forensic Investigations

Abstract

The Government of Kenya has made great attempts at fighting corruption. However, document fraud and manipulation are still rampant. This study aimed to determine the profile of the ink of blue and black ballpoint pens commonly used in Kenya. Through an analysis of the ink composition of these frequently used writing instruments, the study intends to identify any possible connections between document security and the instruments that are widely used in Kenya. Understanding of the subtleties of document fraud will aid in the development of focused counter measures. Results will help current anti-corruption efforts and offer useful recommendations for improving document integrity and thwarting fraudulent activity in future. This was a laboratory experimental study design; whereby mixed methods approaches were used to collect both quantitative and qualitative data. The ink analyses which included the composition of the inks, discrimination, and resolution in different solvents were conducted using thin-layer chromatography (TLC), Fourier Transform Infrared Spectroscopy (FTIR), and Ultraviolet-visible UV-vis) spectroscopy. A total of ten ballpoint pens were included in the study. Six were blue ballpoint ink pens and the remaining four were black from distinct manufacturers. The number of pigments identified in ink from blue and black ballpoint pens varied based on TLC analyses. Importantly, the discriminating power (DP) of blue and black ballpoint pens was 0.87 and 0.83, respectively. In addition, UV-Vis spectroscopy attained a discriminating power (DP) of 0.93 for blue ink and 0.67 for black ink, whereas FTIR spectroscopy had a DP of 1.0 for both blue and black ink. Further, the FTIR spectra analyses identified presence of hydroxyl, carboxyl, amino, nitro, and ester/ether functional groups in the ballpoint ink pens. Multivariate analysis at different wavelengths revealed no statistically significant differences between the absorption of the blue and black inks in different solvents (p > 0.05). This study demonstrates the qualitative composition of blue and black ballpoint pen inks and the functional group. More importantly, the study provides baseline data on the chemical composition of ballpoint pen inks that may be used to establish a database suitable for forensic investigations. The study further demonstrates that TLC, FTIR, and UV-Vis spectroscopy might be useful techniques for discriminating ballpoint pen inks in Kenya.