V n aginsky dating and characterizing writing stamp pad android

The aim of this work was to study the drying process of ballpoint ink, characterised by the disappearance of volatile solvents from the ink entry.Phenoxyethanol is of particularly high interest as it is found in more than 80% of the blue ballpoint pens at different concentrations.

It was also observed that the dyes from the ink strokes did not show significant degradation after one year of storage in the dark.In conclusion, the storage conditions of a questioned document and the initial composition of the dyes in the ink have to be known for correct interpretation of the age of an ink entry.Humidity also increases degradation, which can be explained by the basicity of the paper.The influence of heat on the degradation process was found to be rather weak.Moreover, it is possible to analyze the dye from a stroke directly from the paper (LDI-MS), so the sample preparation is minimized.

The degradation of the dyes methyl violet and ethyl violet in strokes from a ballpoint pen was studied under laboratory conditions influenced by different factors such as light, wavelength of light, heat, and humidity.Measurements over longer periods of time are necessary to follow the degradation of dyes exempt from light exposure.LDI was found adequate and very useful for the analysis of ballpoint dyes directly from paper without further pretreatment.This work also suggests that the court and scientific requirements for standards of reliability are not yet fulfilled by actual ink dating methods for regulatory use in expert testimony.The relative and absolute age of roller and gel ink entries determined by gas chromatography (GC) and UV–vis methods are presented in this paper.The amount of ethoxyethanol stopped decreasing after about 10 days (quantities reached the nanogram range for a 1 cm ballpoint entry), while the aging curves of dipropylene glycol, phenoxyethanol and phenoxyethoxyethanol level off considerably after 2 weeks.