The Discrimination Potential of Ultraviolet-Visible Spectrophotometry, Thin Layer Chromatography, and Fourier Transform Infrared Spectroscopy for the Forensic Analysis of Black and Blue Ballpoint Inks
The knowledge of the discriminating power of analytical techniques used for the differentiation of writing inks can be useful when interpreting results. Ultraviolet-visible (UV-VIS) spectrophotometry, thin layer chromatography (TLC), and diffuse reflectance Fourier transform infrared spectroscopy (FT-IR) were used to examine a population of 21 black and 12 blue ballpoint writing inks. Based on corroborative results of these methods, the discrimination power for UV-VIS, TLC, and FT-IR was determined to be 100% and 98% for the black and blue inks, respectively. Generally, TLC and UV-VIS can be used to differentiate the colorant components (i.e., dyes and some pigments) found in inks. As FT-IR can be utilized to identify some of the noncolorant components, it was determined to be an excellent complementary technique that can be implemented into an analytical scheme for ink analysis.
Document Type: Research Article
Affiliations: 1: Dipartimento di Scienze Chimiche dell’Università, via Marzolo 1, 35131 Padova, Italy. 2: Reparto Carabinieri Investigazioni Scientifiche, S.S. 114 Km. 6,400 – 98128 Tremestieri, Messina, Italy. 3: Dipartimento Farmaco Chimico Facoltà di Farmacia dell’Università, viale Annunziata, 98123 Messina, Italy.
Publication date: November 1, 2008