Revealing chemical evidence from fingerprints through matrix-assisted laser desorption/ionization - mass spectrometry imaging

• NCJ Number: 306215
• Author(s): Paige Hinners
• Date Published: 2020
• Length: 124 pages
• Grant Number(s): 2016-DN-BX-0190
• Agencies: NIJ-Sponsored
• Publication Type: Thesis/Dissertation
• Award: Chemical Imaging of Latent Fingerprint for Forensic Evidence

Annotation

This dissertation presents the author’s efforts to advance the application of matrix-assisted laser desorption/ionization - mass spectrometry imaging (MALDI-MSI) to the chemical analysis of latent fingerprints.

Abstract

The first chapter contains a general introduction to MALDI-MSI, with a focus on the application to fingerprint analysis. The final chapter summarizes the presented work and future directions for the research. The second chapter presents the feasibility of using carbon fingerprint development powder (CFP) as an existing MALDI matrix. This study compared the ionization efficiency of CFP and other commonly used MALDI matrices. The data revealed that CFP is comparable or better than the currently utilized MALDI matrices for latent fingerprint analysis. MALDI-MSI was performed on fingerprints dusted with CFP and lifted with forensic lifting tape, demonstrating that more realistic samples can also be analyzed using MALDI-MSI. (Most importantly, it was shown that MALDI-MSI does not destroy the fingerprint during analysis and the fingerprint can be preserved as forensic evidence. The third chapter investigated the use of titanium oxide development powder (TiO2) as a MALDI matrix and elaborates on the impact of adding additional matrices to the signal-to-noise (S/N) ratio of fingerprint compounds. It was demonstrated that TiO2 worked efficiently as an existing MALDI matrix and did not require the use of a high-resolution mass spectrometer. Additional matrices on top of the TiO2 showed limited success and caused a decrease in intensity for some compounds. However, additional matrix did allow the analysis of TiO2 developed fingerprints in negative mode. Importantly this work emphasized the need for knowledge of traditional matrix applicability in fingerprint analysis. (Published abstract provided)