Some Separations of Black and Red Water Soluble Fiber-Tip Pen Inks by Capillary Zone Electrophoresis and Thin-Layer Chromatography

• NCJ Number: 131266
• Journal: Journal of Forensic Sciences Volume: 36 Issue: 4 Dated: (July 1991) Pages: 1192-1197
• Author(s): S Fanali; M Schudel
• Date Published: 1991
• Length: 6 pages
• Publication Format: Article
• Publication Type: Test/Measurement
• Language: English
• Country: United States of America

Annotation

Capillary zone electrophoresis (CZE) is applied to the analysis of inks.

Abstract

Electropherograms of internal standards of known inks were obtained by CZE and compared with electropherograms of a mixture of inks separated by CZE for a qualitative comparison. The electropherogram will show the results of the electrophoretic separation of the mixture. In another method, the dyes of the inks are separated by reversed phase thin layer chromatography (TLC). Dye spots barely discernible on the chromatographic plate could be extracted and compared by CZE. Application of the second method to ink samples included chromatography, addition of each of the separated spots to part of the whole ink sample, and separation by CZE. This allowed a comparison of the TLC extracted dye to one of the dyes in the ink mixture on the electropherograms. The proposed technique could be useful in the examination of questioned documents. 2 figures and 21 references (Author abstract modified)