Forensic discrimination of automotive sheet glass manufactured in a same production line by quantitative analysis of iron using an ICP-QMS/QMS with an octapole reaction cell

Abstract

 Applications of ICP-QMS/QMS using H₂ as a reaction gas were investigated for the accurate and precise determination of Fe in glass fragments. The maximum signal to background ratio was calculated by dividing ion counts for the sample solution (50 ng mL^－1 Fe in 0.8 mol L^－1 HNO₃) by that obtained for a blank solution (0.8 mol L^－1 HNO₃) at H₂ gas flow rates of 8 and 6 mL min^－1 for m/z＝54 and 56, respectively. The obtained values for ⁵⁴Fe and ⁵⁶Fe in a certified reference glass material (NIST 612) under the optimized condition in the H₂ gas mode showed a good match with the reference value (51±2 μg g^－1) with a precision of <7.1％ by RSD. The number of indistinguishable pairs among the 13 sheet glass samples manufactured using the same production line was limited to 12 of 78 by comparison of only Fe concentrations measured using the method developed herein, demonstrating the potential contribution of Fe analysis to enhanced evidence collection.