Senior Research Chemist, Forensic Science Center, Ministry of the Interior, Moscow,
(Received 8 September 1992; accepted 24 March 1993)
This paper introduces four techniques developed with the goal of estimating the age of ballpoint inks. These techniques are based on using the microspectrophotometric determination of the rates of color changing in inks as a result of the reaction with chemicals—the older the ink the less the rate (procedure 1); a combination of gas chromatographic (GC) and spectrophotometric methods for determining the masses' ratios “volatile component/dye component” in ink that decrease with the age of inks (procedure 2); a GC method of determining the extent of extraction of ink volatile components that decreases as ink ages on paper (procedure 3); a thin-layer chromatographic method for determining age changes in resins and other colorless nonvolatile ballpoint ink components: these changes are detected by observing the resulting thin-layer chromatograms under UV illumination and can be evaluated by using scanning densitometry (procedure 4). Suggestions for further work are proposed.
Paper ID: JFS13517J