Developments in the Analysis of Writing Inks on Questioned Documents

• NCJ Number: 136031
• Journal: Journal of Forensic Sciences Volume: 37 Issue: 2 Dated: (March 1992) Pages: 612-619
• Author(s): J Harris
• Date Published: 1992
• Length: 8 pages
• Publication Format: Article
• Publication Type: Test/Measurement
• Language: English
• Country: United States of America
• Note: Presented at the 37th Annual Meeting of the Canadian Society of Forensic Sciences, Ottawa, Ontario, Canada, October 1-5, 1990.

Annotation

This article describes the development of a 1-mm-diameter micro-hole punch that permits the rapid collection of paper plugs from documents bearing questioned inks.

Abstract

To reduce the time required to collect micro-plugs for the analysis of ink on a document, the Central Forensic Laboratory of the Royal Canadian Mounted Police designed and produced a 1-mm-diameter micro-hole punch capable of punching out sharply defined 1-mm-diameter plugs of paper; it also collects each punched-out plug directly into a 1-drain vial seated below the punch. It can be easily cleaned with suitable cleaning solvents, and it is capable of obtaining samples anywhere on a 8.5 in. x 14 in. document. The punch is activated with a quick downward tap of the punch head. The next stage in an ink analysis involves extracting ink from paper plugs and spotting the ink on thin-layer chromatography (TLC) plates. The Central Forensic Laboratory uses the Drummond Digital Microdispenser for this step. It combines the use of glass pipettes with an accurate one-step digital dispensing gun. The use of the micro-hole punch and the Drummond Digital Microdispenser combine to improve the precision and accuracy of conventional methods and significantly reduce the time required to analyze writing inks by TLC. 13 figures and 5 references