Analysis of the Aging Processes of Writing Ink: Raman Spectroscopy versus Gas Chromatography Aspects

Abstract

This work is devoted to the extremely popular but poorly developed scientific and forensic problem of the estimation of the actual dates of inscriptions placed on paper and made by ballpoint pens. It is shown that the degradation of writing inks with time may be controlled via Raman spectroscopy and gas chromatography. The time intervals for the implementation of each of these methods were determined using the ratios of the Raman peak intensities as degradation characteristics rather than their absolute values. In turn, this eliminates the effect of the concentration of a dye. The mutual influence of the volatile components and dyes of writing inks was also investigated and the time interval within which such influence is critical was found. According to the obtained results, a new methodological scheme for determining the age of documents, which were created at least 40 months ago, was proposed.

Challenges of Forensic-Technical Expertise of Documents for Determining the Terms of Their Production

“…These problems are briefly illustrated in Table 1. Raman spectroscopy method should be also outlined (Gorshkova et al, 2016;Grechukha et al, 2017).…”

“…Identification of components by spectrum characteristics is hard because of limited volume of added trials, including of preconcentration stage is required; Low sensitivity trials (Shevchenko, Temerdashev, Kiseleva, 2012); Hard to identify components trials (Shevchenko, Temerdashev, Kiseleva, 2012); Because of low signal-noise correlations it is very hard to determine many minor components with high degree of certainty Attenuated total reflection Fourier-Transform Infrared Spectroscopy (ATR FTIR) Signal from paper can be higher that signal from written composition; As any IF spectroscopy it has "fingerprint" as a signal: many peaks from different components that do not fit each other. Written composition must be separated before to be identified and that is not always possible (Dirwono et al, 2010) and have been presented at international conferences, was developed on the basis of Raman spectroscopy (Gorshkova et al, 2016;Grechukha et al, 2017;Kochemirovskiy et al, 2015).…”

“…Only three main types (Gorshkova et al, 2016;Grechukha et al, 2017) Suggested spectral methods of documents' examination allow an expert agency to effectively use modern digital technologies. In particular, they provide an opportunity to create universal digital databases of spectrums of different objects of forensictechnical examination that can be later used as standard or informational data in other objects' analysis.…”

“…• Raman spectroscopy (Mazzella, Buzzini, 2005;Lombardi et al, 2006, Chaplin, Clark, 2006Kalantzis, 2008;Geiman, Leona, Lombardi, 2009;Reisner, Cao, Pandya, 2011;Gorshkova et al, 2016;Grechukha et al, 2017).…”

Applications of liquid‐based separation in conjunction with mass spectrometry to the analysis of forensic evidence

“…Under LC‐MS, however, salts are separated from compounds of interest and most compounds are separated from each other, minimizing the suppression effects and simplifying chemical identification. Moreover, they provide a peak for each compound, simplifying the identification of decomposition products of the dyes and pigments, which have been used for dating . One major factor in consistent dating of ink on paper is variation in applied pressure and the thickness of the ink on paper.…”