Forensic Discrimination of Blue Gel Pen Inks by UV-Visible Spectroscopy and Chemometrics.

Bhattacharya, Nikita; Dey, Amrita; Sharma, Spriha

Introduction: In the realm of questioned documents, the domain of ink examination plays a crucial role. Examiners make every effort to compare and identify inks that stem from various writing instruments. The detection of the ink source used in disputed documents, including anonymous letters, insurance frauds, and will frauds, is considered a high priority in questioned document examinations. Materials and Method: In the present study a novel and efficient technique has been presented using UV-Visible spectroscopy combined with chemometrics such as principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) to distinguish between 38 different commercially available blue gel pen inks. Results: The visual analysis of the spectroscopic peaks resulted in a discriminating power (DP) of 94%. Applying PCA and PLS-DA to the spectra delivered 99% and 100% DP respectively. High R-square value (0.967) and low RMSE value (0.057) was observed. Conclusion: The results show that by utilizing the low-cost technique of UV-Visible spectroscopy and employing multivariate data analysis, reliable and replicable differentiation between blue gel pen inks can be achieved.

PRINCIPAL components analysis; INSURANCE crimes; DISCRIMINANT analysis; ULTRAVIOLET-visible spectroscopy; MULTIVARIATE analysis

Journal of Punjab Academy of Forensic Medicine & Toxicology, 2024, Vol 24, Issue 1, p98

0972-5687

Academic Journal

10.5958/0974-083X.2024.00016.5