Handheld X-Ray Technology Unveils New Forensic Tool

In a leap forward for forensic analysis, a study by researchers at the University of Porto has revealed that handheld X-ray fluorescence spectrometers (HHXRF) can be used to analyze cigarette ash. This innovation offers a new way to identify suspects and witnesses in criminal investigations. The study, published in Forensic Science International, demonstrates how this technology can distinguish between different tobacco brands based on their ash’s elemental concentration, providing valuable forensic evidence while preserving the integrity of the sample (1).

X-ray fluorescence analysis of cigarette ash © MarijaBazarova - stock.adobe.com

Read More: Cigarette Analysis Using Spectroscopic Techniques

The Study and Its Findings

Cigarette butts have long been recognized as critical pieces of forensic evidence due to the potential for DNA analysis. However, cigarette ash has not been as extensively studied, particularly in terms of its inorganic elemental composition. The research team, including Beatriz P. Senra, Helena Ribeiro, and Alexandra Guedes from the Department of Public Health and Forensic Sciences at the University of Porto, aimed to fill this gap. They focused on the elemental concentration of cigarette ash to determine whether it could be used to differentiate between various tobacco brands (1,2).

The researchers conducted a survey among 190 people in Portugal to identify the 10 most smoked tobacco brands. They purchased packs of these brands and used the Oxford Instruments X-MET7500 HHXRF spectrometer to analyze the ash. The spectrometer’s non-destructive nature allows for onsite analysis, minimizing contamination and sample loss, a significant advantage over traditional, more invasive methods (1).

Methodology

The study utilized an HHXRF spectrometer with a detection range suitable for a comprehensive elemental analysis. Each cigarette was smoked, and the resulting ash was collected and placed in a plastic cylinder box for analysis. The spectrometer, calibrated with certified reference materials, provided the elemental concentration of each sample in parts per million (ppm).

Five replicate measurements were taken for each sample, resulting in a total of 275 analyses. The elements analyzed included aluminum, calcium, chlorine, copper, iron, potassium, manganese, phosphorus, rubidium, sulfur, silicon, strontium, titanium, and zinc. These elements were chosen because they were found in the highest concentrations, allowing for robust analysis and comparison (1).

Statistical Analysis

Data analysis was performed using IBM SPSS Statistics. Average concentrations and standard deviations for each element were calculated. A normality test (Kolmogorov-Smirnov) confirmed the data's suitability for parametric statistical analysis. The researchers conducted a one-way ANOVA test followed by Tukey’s post-hoc test to identify significant differences in elemental concentrations both within each brand and among different brands (1).

Additionally, hierarchical cluster classification was employed to determine if the distinct brands could be discriminated based on their elemental profiles. This analysis used standardized values to reduce scale effects and revealed that the HHXRF could successfully differentiate between the brands (1).

Conclusion

The study concludes that HHXRF technology can effectively analyze cigarette ash to differentiate between tobacco brands, providing a valuable new tool for forensic investigations. This method’s non-destructive nature and ability to perform on-site analysis represent significant advancements over traditional techniques. By enabling rapid, accurate, and cost-effective analyses, HHXRF opens new possibilities for forensic science, particularly in linking suspects to crime scenes through cigarette ash (1).

The work of Senra, Ribeiro, and Guedes marks a significant step forward in forensic analysis, offering law enforcement a new, efficient method to gather and analyze evidence. This study not only highlights the potential of HHXRF technology but also underscores the importance of continuous innovation in forensic science to enhance investigative capabilities (1,2).

References

(1) Senra, B. P.; Ribeiro, H.; Guedes, A. 2024. Application of Handheld X-ray Fluorescence Spectrometers in Forensic Analysis of Cigarette Ash. Forensic Sci. Int. 2024, 361, 112083. DOI: 10.1016/j.forsciint.2024.112083

(2) Chakraborty, S. A. Review on Chemical Composition and Forensic Analysis of Tobacco and Ash in Cigarettes and Bidis. Innovation and Integrative Research Center Journal 2024, 2 (6), 165–183. Home Page.https://iircj.org/wp-content/uploads/2024/06/18.A-Review-on-Chemical-Composition-and-Forensic-Analysis-of-Tobacco-and-Ash-in-Cigarettes-and-Bidis.pdf (accessed 2024-08-07)