Carbon‐Based Fingerprint Powder as a One‐Step Development and Matrix Application for High‐Resolution Mass Spectrometry Imaging of Latent Fingerprints

Carbon‐based materials are often used as matrices for matrix‐assisted laser desorption/ionization mass spectrometry ( MALDI ‐ MS ) and its imaging ( MALDI ‐ MSI ). However, researchers have refrained from using carbon‐based fingerprint powder ( CFP ) as a matrix due to high background and contamination. In this work, the compatibility of CFP is reevaluated with MALDI ‐ MSI using a high‐resolution mass spectrometer ( HRMS ) and compared to traditional organic matrices. Relevant fingerprint compounds were easily distinguished from carbon cluster peaks when using HRMS . For fair comparison, half of a fingerprint was dusted with CFP while the other half was dusted with traditional organic matrices. All compounds studied had comparable, or higher, signal‐to‐noise (S/N) ratios when CFP was used as the matrix. Additionally, chemical image qualities closely followed the trend of S/N ratios. CFP proved to be an effective one‐step development and matrix application technique for MALDI ‐ MSI of latent fingerprints, when carbon cluster peaks are well separated by a HRMS .