Problems of Forensic Sciences 2010 Vol. 82 (LXXXII) 133-140
INFLUENCE OF STORAGE CONDITIONS ON AGEING OF COLOUR DYE-BASED INKJET PRINTING INKS
Małgorzata SZAFARSKA1, Renata WIETECHA-POSŁUSZNY1, Michał WOŹNIAKIEWICZ1, Craig HUGHES2, Paweł KOŚCIELNIAK1, 3
1Faculty of Chemistry, Jagiellonian University, Kraków, Poland
2Nottingham Trent University, Nottingham, Great Britain
3Department of Criminalistics, Institute of Forensic Research, Kraków, Poland
Streszczenie
An approach to monitoring the degradation of colour inkjet printing inks by UV/Vis spectrometry is presented in this paper. Printouts were kept in various environmental conditions, varying in light, heat and humidity, to determine the effect of these externals on the ageing rate and to find the optimal storage conditions for further examination of inkjet printed questioned documents. Absorption readings were taken regularly for 6 weeks in order to monitor any change in absorption. It was found that ageing effects were only observed for printouts stored in natural light, and the printouts sealed in a bag with silica gel aged slower than the printouts exposed to the room environment. Therefore, the optimal storage conditions to preserve printouts were established as a dry and dark environment. It was found that cyan ink containing substituted phthalocyanine can be considered as a marker of the document age.
Słowa kluczowe
Inkjet printing inks; Document ageing; UV/Vis spectrometry; Ink degradation.