The assessment of ink age determination by chemical tecniques on naturally and artificially aged papers with regard to forensic document examination

It is aimed to contribute to ink age determination studies by determining the quantity change curve with time of phenoxyethanol (PE), which is one of the ink components, in order to determine the age of a writing or signature applied on the document. In our study; each month for 12 months, lines were drawn on standart A4 papers by the same person using 10 blue and 10 black ballpoint pens, 5 blue and 5 black gel pens in different brand and models. Papers drawn in line were stored at 45-55% humidity and 20-23°C in the air conditioning cabinet. Our archive documents of 0-12 months were analyzed by Gas Chromatography Mass Spectrometry (GC-MS) device for PE quantitation and concentration-time graph was drawn according to the amounts of PE. It is observed that the amount of PE was higher in the 0-day documents than the other months and the loss rate of PE in the 1-month documents reached 90% so this period is determined as "fast drying" phase, and in 2-6 month documents, the loss rate of PE decreased gradually so this period is determined as "slow drying" phase. PE can not be determined in gel pen ink contents so it was understood that a different substance was used as solvent. In the second stage of the experiment, our 0-day documents were artificially aged with a 300 watt light bulb simulating daylight for 50 hours, 10 hours at 60°C in the air conditioning cabinet and 20 seconds with an iron at 95°C.It has been concluded that the documents aged artificially with light, heat and iron are compatible with the amounts of PE, respectively 6-9 months, 5-6 months and 6-7 months naturally aged documents. It was observed that instead of specifying the exact time frame for the creation date of natural and artificially aged documents, estimated time intervals can be given, and the amount of PE can be used to compare the time of creation of writings and signatures in a document. It was concluded that more studies should be done on ink age determination, including volatile components, dyestuffs and resins.