Application of laser induced breakdown spectroscopy to examination of writing inks for forensic purposes

Agnieszka Kula; Renata Wietecha-Posłuszny; Katarzyna Pasionek; Małgorzata Król; Michał Woźniakiewicz; Paweł Kościelniak

doi:10.1016/j.scijus.2013.09.008

Application of laser induced breakdown spectroscopy to examination of writing inks for forensic purposes

Sci Justice. 2014 Mar;54(2):118-25. doi: 10.1016/j.scijus.2013.09.008. Epub 2013 Oct 19.

Authors

Agnieszka Kula¹, Renata Wietecha-Posłuszny², Katarzyna Pasionek³, Małgorzata Król⁴, Michał Woźniakiewicz⁵, Paweł Kościelniak⁶

Affiliations

¹ Jagiellonian University, Department of Analytical Chemistry, Laboratory for Forensic Chemistry, 3 Ingardena St., 30-060 Krakow, Poland. Electronic address: solarz@chemia.uj.edu.pl.
² Jagiellonian University, Department of Analytical Chemistry, Laboratory for Forensic Chemistry, 3 Ingardena St., 30-060 Krakow, Poland. Electronic address: wietecha@chemia.uj.edu.pl.
³ Jagiellonian University, Department of Analytical Chemistry, Laboratory for Forensic Chemistry, 3 Ingardena St., 30-060 Krakow, Poland. Electronic address: kasiapas205@wp.pl.
⁴ Jagiellonian University, Department of Analytical Chemistry, Laboratory for Forensic Chemistry, 3 Ingardena St., 30-060 Krakow, Poland. Electronic address: krolm@chemia.uj.edu.pl.
⁵ Jagiellonian University, Department of Analytical Chemistry, Laboratory for Forensic Chemistry, 3 Ingardena St., 30-060 Krakow, Poland. Electronic address: wozniaki@chemia.uj.edu.pl.
⁶ Jagiellonian University, Department of Analytical Chemistry, Laboratory for Forensic Chemistry, 3 Ingardena St., 30-060 Krakow, Poland; Institute of Forensic Research, 9 Westerplatte St., 31-033 Krakow, Poland. Electronic address: koscieln@chemia.uj.edu.pl.

PMID: 24630321
DOI: 10.1016/j.scijus.2013.09.008

Abstract

The research was focused on the analysis of writing inks using the laser induced breakdown spectroscopy (LIBS) technique. 34 samples of blue, 30 of black, and 21 of red writing inks were analyzed under optimized conditions to determine the variation of chemical composition of inks between different colours, brands and types. Nine elements (Ba, Cr, Cu, Fe, Li, Mo, Mn, Ni and W) were taken into account during comparative analysis of inks. Because of the strong effect of the paper spectrum, elements often found in inks (Ca, Al, Mg, Na, Ti, and Si) were eliminated from LIBS analysis of inks. It was determined that the LIBS method is capable of revealing qualitative elemental differences between ink samples. The discrimination power of this method was found to be 83, 82 and 61% for blue, black and red inks, respectively. Inks produced by the same producer were able to be differentiated in some cases. The results showed the potential of LIBS for forensic purposes as an effective and robust technique, requiring a small amount of sample and giving analytical information in a very short time.

Keywords: Elemental analysis; Forensic science; Ink analysis; Laser induced breakdown spectroscopy; Questioned document examination; Writing inks.

Publication types

Research Support, Non-U.S. Gov't