title: How Much Can a Forensic Laboratory Do to Discriminate Questioned Ink Entries?
abstract: Questioned document examiners are frequently required to determine whether the questioned ink entries on a document are written with the same ink, either for forged document identification or relative ink dating. How many methods are sufficient to discriminate potentially different inks? In this paper, 18 blue ballpoint inks were first nondestructively examined with a video spectral comparator. The ink entries were subsequently extracted with organic solvents for analysis of the volatile solvents and dyes by GC/MS, TLC, and LC-MS/MS. The 18 ink samples were divided into 10, 9, 12, and 14 categories by these four methods, respectively. With the combined results, there were only two inks that remained indistinguishable, but they were further differentiated by microscopy. Therefore, to achieve effective discrimination of ballpoint ink entries, the authors suggest that a complete examination should include an analysis of their optical features, volatile solvents, and dyes as well as the ink quality.
authors.affiliation: Institute of Forensic Science, Ministry of Justice, No. 1347 West Guangfu Road, Shanghai, 200063, China.|Department of Forensic Science, Shanghai Medical College, Fudan University, No. 138 Yi Xue Yuan Road, Shanghai, 200032, China.
authors.forename: Qiran
authors.initials: Q
authors.lastname: Sun
authors.affiliation: Institute of Forensic Science, Ministry of Justice, No. 1347 West Guangfu Road, Shanghai, 200063, China.
authors.forename: Yiwen
authors.initials: Y
authors.lastname: Luo
authors.affiliation: Institute of Forensic Science, Ministry of Justice, No. 1347 West Guangfu Road, Shanghai, 200063, China.
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Institute of Forensic Science, Ministry of Justice, No. 1347 West Guangfu Road, Shanghai, 200063, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Yang
authors.affiliation: Institute of Forensic Science, Ministry of Justice, No. 1347 West Guangfu Road, Shanghai, 200063, China.
authors.forename: Che
authors.initials: C
authors.lastname: Xu
keywords: ballpoint ink discrimination; dye; forensic science; optical feature; questioned document examination; solvent