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Inhomogeneity and Aging of Ballpoint Pen Inks Inside of Pen Cartridges

NCJ Number
Journal of Forensic Sciences Volume: 50 Issue: 3 Dated: May 2005 Pages: 542-547
Jan Andrasko Ph.D.; Marcin Kunicki M.Sc.
Date Published
May 2005
6 pages
This study examined the aging and inhomogeneities of inks at the tip of various pen cartridges.
Ink dating is an important component of document analysis, where a common task is to investigate whether two or more documents have been written with the same type of ink. The current analysis relied on high pressure liquid chromatography (HPLC) to examine the inhomogeneity and aging of ballpoint pen inks inside of cartridges. Methodology involved making ink entries in the form of asterisks on ordinary white copy paper using various ballpoint pens. Analysis of the ink inside the pen cartridges showed no signs of aging in terms of dye composition changes but the ink entries on the paper were observed to be inhomogeneous in terms of their concentration of phenoxyethanol, a compound commonly found in ballpoint inks. Detectable and sometimes considerable aging of the inks was apparent near the tip of pen cartridges not used for writing for many years; evaporation of phenoxyethanol and aging of cationic dye mixture were apparent when writing with these long-unused pens. The findings suggest that when analyzing ink samples, samples should be taken from several ink entries and samples from the beginning of the writing should be avoided. Tables, figures, references