Sector field ICP-MS applied to the forensic analysis of commercially available adhesive packaging tapes

An analytical method to determine trace element concentrations and their ratios in the glue of brown PSA packaging tapes is described. The method relies on acid digestion in quartz vessels inside a closed microwave unit and measurement by sector field ICP-MS. This methodology was applied to nine tape rolls purchased from three different shops of three different chain stores. It was possible to discriminate both between brands and within brand for all three brands. In the case of one brand, for rolls originating from the same product line but from different production batches, it was shown that the 'between batch' difference is detectable whilst there is no statistically significant difference within rolls from the same production batch. This combination of 'between batch' differences and 'within batch' consistency may provide the forensic scientist with the means to discriminate between tape rolls even if they come from the same product line.