Ink analysis from typed script of electronic typewriters by high performance thin layer chromatography

Multivariate chemometrics for the forensic discrimination of blue ball-point pen inks based on their Vis spectra

“…Paper chromatography has been among the oldest destructive methods employed in ink analysis and has been used especially for organic dye based inks [5][6][7] since the older iron-gallotanate inks are difficult to separate by chromatography. Thin layer chromatography (TLC) [2,[8][9][10] and its variants, including disk chromatography [11] and high performance thin layer chromatography (HPTLC) [12][13][14], have gradually replaced paper chromatography and have proved to be a satisfactory equivalent for separating ink components. Observation of thin layer chromatograms under alternative light sources, the use of infrared luminescence and microspectrophotometry have also been employed in an attempt to achieve better characterization of the TLC bands [15][16][17].…”

Forensic Science

“…Methods for dating documents have been reviewed (594). The analysis of ink from typewriters was carried out by TLC (595).…”

Forensics Analysis of Typewriter and Typewritten Documents

“…he beauty of letters written on a paper T fascinates the attention of the reader particularly in case of scripts produced by the electronic typewriter in offices and institutions (5). There are various typed and office printed documents which have been produced in different forms for a significant time period.…”