Problems of Forensic Sciences 2017 Vol. 110 (CX) 111-137
ANALYSIS OF THE ELEMENTAL COMPOSITION OF GLASS FRAGMENTS BY LA-ICP-MS METHOD. PART I. OPTIMAL CONDITIONS FOR MICRO-SAMPLING OF CONTAINER GLASS FOR FORENSIC PURPOSES
Dariusz WILK1,2, Ewa BULSKA1
1Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland
2Department of Criminalistics, Faculty of Law and Administration, Jagiellonian University, Krakow, Poland
Streszczenie
Laser ablation inductively coupled plasma with mass spectrometry (LA-ICP-MS) allows for elemental analysis of the glass. LA-ICP-MS measurements are capable for providing reliable information about main and trace elements content, when optimal laser ablation conditions are applied and heterogeneity of evidence and control samples is taken into account during micro-sampling. The aim of the research was to set optimum conditions and proper methodology of micro-sampling for elemental analysis of glass fragments, particularly of samples taken from brown and green containers. The studies were focused on heterogeneous layers of container glass, which were created during manufacture processes (hot-end coatings) and corrosion processes.
The research shows that laser ablation in point mode with 20 Hz repetition rate allows for micro-sampling of representative part of the material, i.e. bulk analysis, without preparation of the sample. Many important elements for discrimination purposes (Fe2O3, Cr2O3, K2O), including traces, can be determined in small glass fragments during LA-ICP-MS analysis with 20 Hz repetition rate. Applicability and suitability of CRM NIST 610 and CRM NIST 612 in analysis of container glass samples was confirmed within studies. It was also confirmed that elemental analysis of container glass can be performed with the use of 213 and 266 nm laser wavelength. Nevertheless lower fractionation effect, especially during measurements of colorless glass, was observed with 213 nm laser wavelength.
Słowa kluczowe
Glass fragments, Container glass, Laser ablation, ICP-MS, Optimization.