Forensic Characterization of Gel Pen Inks with Thin Layer Chromatography and Ultraviolet Spectroscopy Technique

• Published in: Journal of forensic science and medicine Vol. 11; no. 2; pp. 106 - 111
• Main Authors: Kaur, Harjot, Sharma, Tina, Gautam, Archana, Mishra, Vaibhav
• Format: Journal Article
• Language: English
• Published: India Wolters Kluwer - Medknow 01.04.2025; Medknow Publications and Media Pvt. Ltd; Medknow Publications & Media Pvt. Ltd; Wolters Kluwer Medknow Publications
• Edition: 2
• Subjects: Chromatography; forensic science; Forensic sciences; gel pen ink; Methods; Original Article; questioned document; Spectrum analysis; thin layer chromatography; uv spectroscopy; Gel pen ink; forensic science; uv spectroscopy; questioned document; thin layer chromatography
• ISSN: 2349-5014; 2455-0094
• DOI: 10.4103/jfsm.jfsm_149_23

Abstract Background: Using a comprehensive approach that combines Thin Layer Chromatography (TLC), UV-visible spectroscopy, and Adobe Photoshop image manipulation, this study aims to authenticate and identify Gen gel pens. Aim and Objectives: The principal objective is to describe gel pen ink compositions and develop an authentication process for them. Thirty gel pen ink samples total-ten of each for the colors red, black, and blue-are the subject of the study. Goals include applying Adobe Photoshop for improved visual differentiation and using TLC and UV-visible spectroscopy for preliminary characterization. Materials and Methods: To characterize the compositions of thirty gel pen ink samples, Thin Layer Chromatography and UV-visible spectroscopy were applied. To improve the visuals, images were turned upside down and their brightness was changed using Adobe Photoshop. Gel pen ink matching was tested in a blind trial that combined analytical findings with Photoshop-enhanced visual differentiation. Results: 76% of samples could be distinguished clearly, according to analytical data, and 40% of samples showed UV absorption at 237.5 nm regardless of the colour of the ink. Remarkably, on the UV Visible Spectrum, 76.6% showed distinct peaks. A major factor in the ability to visually distinguish ink samples was Adobe Photoshop. Different ink samples could be identified using UV-visible spectroscopy peak variations; 23.3% of the samples showed nonspecific peak patterns that could be seen in photos that had been Photoshopped. Conclusion: The combined findings provide insightful information about gel pen ink differentiation and suggest a possible approach for model identification and authentication. This method combines Adobe Photoshop image manipulation with analytical methods like TLC and UV-visible spectroscopy.