NCJ Number
77027
Journal
Canadian Society of Forensic Science Volume: 14 Issue: 1 Dated: (March 1981) Pages: 23-31
Date Published
1981
Length
9 pages
Annotation
Forged admission tickets were linked to the press that printed them through a technique for differentiating papers by thin layer chromatography of fluorescent brightners contained in white papers and of dyes present in colored papers.
Abstract
The technique was used in a recent British case where forged admission tickets to a cricket test match were differentiated from the genuine tickets by a preliminary physical examination with a stereomicroscope using direct, transmitted, and ultraviolet light. A similar physical examination established that the paper of the forged tickets was similar to blank papers that the police had seized from a printing press alleged to have been used in printing the forged tickets, but the results could not be considered conclusive. Since the ultraviolet examination revealed that all of the papers contained fluorescent brightners, the thin layer chromatography test was applied to compare the brightners and the dyes. The methods of extracting the brightners and dyes from the papers and of applying the thin layer chromatography are described, and the results for white, pink, brown, and green papers are presented. However, the presence of similar origin since different manufacturing companies may use similar substances. Other physicochemical tests and fiber analysis are necessary before a final conclusion can be reached. Thin layer chromatography is more sensitive than other chemical methods and causes only minimum damage to documents. The method is also quick and its results may be used as evidence in court. Photographs, data tables, and a 13-item reference list are included.