20.500.12556/DKUM-94208 Evaluating the aging of blue pen inks using ToF-SIMS and multivariate statistical analysis This study presents an analytical methodology for the differentiation and identification of blue pen inks aged over a one-year period. The main aim was to determine whether blue pen strokes made one year apart using the same six commercially available blue pens could still be reliably assigned to those specific blue pens. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to acquire both spectral and imaging data from blue pen strokes made one year apart, which were then analyzed using multivariate statistical tools, i.e., principal component analysis (PCA) and multivariate curve resolution (MCR). These analyses enabled the extraction of unique features for each blue pen ink. The results showed that blue pen inks remained distinguishable even after one year, despite detectable aging effects. Moreover, the secondary ion signals that were previously identified as unique chemical markers at specific m/z values persisted throughout the one-year interval and were used for PCA scaling. Effective separation of blue pens by PCA was achieved only after applying customized spatial and spectral scaling. Furthermore, MCR analysis independently confirmed the grouping of blue pen strokes made one year apart. This work confirms that the combined ToF-SIMS and multivariate statistical analysis (MVSA) methodology retains its discriminative power over the extended time period, enabling the exact attribution of aged blue pen inks to their original writing. The methodology has significant advantages for forensic investigations involving dated or disputed handwriting signatures. Tof-SIMS MVSA MCR PCA document forgery ink aging ponarejanje dokumentov staranje črnila modro črnilo za nalivnik true false true Elsevier Angleški jezik Slovenski jezik https://www.sciencedirect.com/journal/microchemical-journal © 2025 The Authors Članek v reviji 2025-08-08 10:46:32 2025-08-08 10:46:32 2025-08-09 03:20:03 0000-00-00 00:00:00 2025 0 0 11 str. Vol. 216, [article no.] 114777 2025 0000-00-00 Zaloznikova Objavljeno NiDoloceno 2025-07-05 2025-08-01 2025-08-05 544.5/.6 245200899 10.1016/j.microc.2025.114777 1095-9149 1-s2.0-S0026265X25021241-main.pdf 1-s2.0-S0026265X25021241-main.pdf 1 1443F4765C0994E33049A493ED832B6B fc8a6d4dd3564473e8ae51676e37fcb0bd9a1417442b216d579a1d1d79b04c54 af432859-7434-11f0-bafb-00155d000105 https://dk.um.si/Dokument.php?lang=slv&id=194944 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0