Elemental Analysis of Packaging Tapes by LA-ICP-MS and LIBS

• NCJ Number: 252066
• Author(s): Claudia Martinez-Lopez, Masataka Sakayanagi, Jose R. Almirall
• Date Published: May 2018
• Length: 9 pages
• Agencies: NIJ-Sponsored
• Award: Characterization and comparison of tape evidence using elemental profiling methods and chemometric analyses

Annotation

This article reports on a project that developed and applied laser induced breakdown spectroscopy (LIBS) and laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS) to the characterization and comparison of eight packaging tape samples manufactured in Asia.

Abstract

The application of LIBS for the analysis of tape samples is reported in this article for the first time. The results of LIBS were compared to LA-ICP-MS as a reference technique and also in assessing whether these techniques complement each other for the analysis of this type of sample. The developed methods can be applied to the forensic analysis of other types of tapes and potentially to the forensic analysis of other polymeric materials. The use of these laser methods enabled the detection of up to 7 elements by LIBS and 11 elements by LA-ICP-MS. In addition, LIBS was especially useful in detecting elements that were problematic for LA-ICP-MS, such as lithium and potassium. Multivariate analysis of the data was used to visualize chemical similarities or differences obtained by each technique. The area under selected peaks was integrated after the spectra were normalized to the signal intensity. This strategy provided the best reproducibility and repeatability. From the comparison criteria evaluated in this study, +5s produced the lower error rates for the comparison of packaging tapes for the selected elements. These results indicate that LIBS is a viable alternative to the previously reported LA-ICP-MS for forensic analyses and comparisons of tape evidence. 1 figure (Publisher abstract modified)