ISSN: 0022-1198
CODEN: JFSCA
Page Count: 14

Analysis of Ballpoint Pen Inks by Diffuse Reflectance Infrared Spectrometry
Bartick, EG
Chemist and research chemist, Forensic Science Research Unit, FBI Laboratory, FBI Academy, VA

Merrill, RA
Chemist and research chemist, Forensic Science Research Unit, FBI Laboratory, FBI Academy, VA

(Received 20 July 1991; accepted 4 September 1991)

Abstract

The primary method for the analysis of inks is thin-layer chromatography (TLC), which only permits comparison of dye components. Studies have been done on the usefulness of diffuse reflectance (DR) with Fourier transform infrared (FT-IR) spectrometry, using a direct deposit sampling technique for the analysis of ballpoint pen inks. This technique allows screening of a composite ink as a whole, including its dye components, resins, and other additives. A total of 184 ink samples were analyzed by FT-IR, and searchable spectral libraries were created of both whole and extracted inks. The results indicate that the additional information provided by the DR analysis, combined with the complementary information from the TLC analysis, provides enhanced value to the forensic examination of inks.

Keywords:
questioned documents, inks, spectroscopic analysis, ballpoint pen ink, diffuse reflectance, infrared spectrometry, dyes, resins, spectral library

Paper ID: JFS13260J
DOI: 10.1520/JFS13260J
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