ISSN: 0022-1198
CODEN: JFSCA
Published Online: 1 November 2002
Page Count: 9

Evaluation of Laser Desorption Mass Spectrometry and UV Accelerated Aging of Dyes on Paper as Tools for the Evaluation of a Questioned Document
Grim, DM

Allison, J
Michigan State University, MI

Siegel, J
School of Criminal Justice, Michigan State University, MI

(Received 8 July 2002; accepted 29 June 2002)

Abstract

Laser desorption mass spectrometry (LDMS) may be used for the detection and identification of dyes found in inks. Naturally-aged and artificially-aged blue and black ballpoint pen inks containing the cationic dye methyl violet were analyzed on paper. The average molecular weight of the dye sample was calculated from LD mass spectral data and plotted versus time. The resulting aging curves demonstrate that, as dye degradation increases, the average molecular weight of the dye decreases. Typical variables involved in ink aging, such as the type of paper and ink formulation, were investigated. Results show that these variables influence the rate of dye degradation. Furthermore, UV accelerated aging has been developed and tested as an alternative to thermal approaches.

Keywords:
forensic science, questioned documents, methyl violet, accelerated aging, mass spectrometry, ink, dyes

Paper ID: JFS15558J
DOI: 10.1520/JFS15558J
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