NCJ Number
218675
Date Published
July 2005
Length
17 pages
Annotation
This study examined the use of capillary electrophoresis as an analytical tool for forensic analysis of dyes contained in ballpoint pen inks.
Abstract
Capillary electrophoresis has been shown to be a powerful analytical tool for forensic analysis of dyes contained in ballpoint pen inks. The anionic capillary electrophoresis buffer was found to effectively separate black ballpoint ink dye components with higher sensitivity, faster analysis time, and more definitive chemical identification than thin-layer chromatography procedures. Capillary electrophoresis also can detect solvents and other ink additives that are not dyes in the same experiment. Capillary electrophoresis allows ease of sample preparation with the ability to separate and identify dye compounds based on a calculated electrophoretic mobility and a characteristic ultraviolet-visible spectrum. Determining ink sources used on a variety of documents is a key priority for forensic document examiners. Inks are complex mixtures of colorants, vehicles, and additives, which are adjusted in composition to produce the desired writing characteristics. This study examined capillary electrophoresis with ultraviolet –visible photodiode array detection (190-600 nm) as an alternative separation and identification tool for forensic ink examination. Various dye compounds and black ballpoint pen inks were investigated to survey possible samples encountered by forensic ink examiners. References