NCJ Number
138352
Journal
Journal of Forensic Sciences Volume: 37 Issue: 4 Dated: (July 1992) Pages: 1149-1157
Date Published
1992
Length
9 pages
Annotation
High performance liquid chromatographic (HPLC) systems were developed to examine blue non-ball pen inks; using an isocratic chromatographic system, along with a multiwavelength detection system, over 100 blue non-ball pen inks were distinguished.
Abstract
The chromatogram of each ink was obtained at all wavelengths in the ultraviolet and visible regions. Peak purity was determined by examining the ultraviolet spectrum of each eluting peak in the chromatogram. Comparison of peaks in different chromatograms having similar retention times was achieved by obtaining the absorbance spectrum of the peak, together with its first and second derivatives. The technique involving the isocratic chromatographic system and the multiwavelength detection system was shown to be reproducible by repeated extraction and analysis of each sample. The technique's primary advantage over traditional HPLC detectors was that complete chromatographic and spectral data could be collected simultaneously using a sample size of a few nanograms. The increased sensitivity offered by the technique enables meaningful data to be obtained from ink samples previously considered to be too small to work with. In addition, the improved resolution associated with HPLC separations allows even closely related samples to be differentiated. In turn, this gives the examiner a greater degree of certainty when comparing two ink samples and may result in greater evidential value being placed on this type of analysis. 8 references and 8 figures