Studying of Handwritten Strokes Aging Kinetics by High-Performance Liquid Chromatography-Mass Spectrometry

One of central problems of the technical and forensic examination of documents is the determination of the time and sequence of ink depositions by such conventional writing instruments as ballpoint pens. To solve it, it is necessary to obtain information on the composition of the ballpoint pen ink used for recordings, on what qualitative and quantitative changes the ink components underwent in the time after application and under the action of environmental or external sources, such as photo, thermal, UV, IR, or microwave exposure. The purpose of this work was to develop an approach that enables the identification of changes in the composition of inks that occur in the strokes over time and to determine the time dependences ensuring the evaluation of the time of application. The possibilities of liquid chromatography-mass spectrometry in revealing changes in the composition of inks of BIC Original, Corvina 51, and Pilot ballpoint pens were estimated. The dye degradation processes under the effect of UV radiation on strokes was simulated, and the kinetic parameters describing the degree of dye conversion were determined.