Mass spectrometry imaging of illicit drugs in latent fingerprints by matrix-free and matrix-assisted desorption/ionization techniques

Abstract

Compared with classical matrix-assisted laser-desorption ionization mass spectrometry (MALDI), the matrix free-based strategies generate a cleaner background, without significant noise or interference coming from an applied matrix, which is beneficial for the analysis of small molecules, such as drugs of abuse. In this work, we probed the detection efficiency of methamphetamine, heroin and cocaine in nanostructure-assisted laser desorption-ionization (NALDI) and desorption electrospray ionization and compared the sensitivity of these two matrix-free tools with a standard MALDI mass spectrometry experiment. In a typical mass spectrometry imaging (MSI) setup, papillary line latent fingerprints were recorded as a mixture a common skin fatty acid or interfering cosmetics with a drug. In a separate experiment, all drugs (1 µL of 1 μM standard solution) were detected by all three ionization techniques on a target. In the case of cocaine and heroin, NALDI mass spectrometry was the most sensitive and revealed signals even from 0.1 μM solution. The drug/drug contaminant (fatty acid or cosmetics) MSI approach could be used by law enforcement personnel to confirm drug abusers of having come into contact with the suspected drug by use of fingerprint scans at time of apprehension which can aid in reducing the work of lab officials.

Methodologies Applied to Fingerprint Analysis

“…This technique requires spraying a matrix on the sample, so that ionization can occur. Research in this field is important not only for an efficient technique but also for matrix efficiency and the search for sustainable and cheaper materials (). A good matrix is essential for MALDI‐MS/ MSI analysis, since the matrix will support the ionization of the analytes in the sample.…”

The forensic exploitation of fingermark chemistry: A review

“…Amphetamines: amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine (Ecstasy) Day, Edwards, Dobrowski, and Voice (2004a), Day, Edwards, Dobrowski, and Voice (2004b), Szynkowska, Czerski, Rogowski, Paryjczak, and Parczewski (2009), West and Went (2009), Szynkowska, Czerski, Rogowski, Paryjczak, and Parczewski (2010), Clemons et al (2013), Groeneveld, de Puit, Bleay, Bradshaw, and Francese (2015), Muramoto, Forbes, van Asten, and Gillen (2015), Skriba and Havlicek (2018), Souza, de Oliveira, Oliveira, Silva, and Rubim (2018), Hudson et al (2019) Aspirin Day et al (2004aDay et al ( , 2004b, West and Went (2008), Ng, Walker, Tahtouh, and Reedy (2009), Banas et al (2012), Banas, Banas, Breese, Loke, andLim (2014), Sundar and Rowell (2014), Sundar and Rowell (2015) Barbital Day et al (2004aDay et al ( , 2004b Benzodiazepines: diazepam, flunitrazepam, lorazepam [3-Oglucuronide], nitrazepam Day et al (2004aDay et al ( , 2004b, Goucher, Kicman, Smith, and Jickells (2009), Ng et al (2009), Moule et al (2017) Caffeine [paraxanthine, theobromine, theophylline] Day et al (2004aDay et al ( , 2004b, West and Went (2008), Ng et al (2009), Bradshaw et al (2012), Clemons et al (2013), Kuwayama et al (2013), Sundar and Rowell (2014),…”

Interpol review of fingermarks and other body impressions 2016–2019

“… Preliminary/Pilot studies : The following articles aim at detecting contaminants in fingermarks without ridge pattern imaging. For this reason, they are not extensively described: hyperspectral SRS to image exogenous compounds in spiked fingermarks (i.e., gun powder and benzoic acid) [ 193 ], PS-MS to detect illicit drugs in spiked fingermarks [ 469 ] or from fingermarks left by drug users [ 470 ], IR laser ablation coupled to vacuum capture and MALDI-MS to detect caffeine and condom lubricant in spiked fingermarks [ 471 ], silver sputtering combined with MALDI-MSI to detect flunitrazepam-spiked fingermarks [ 472 ], PDMS-PDA-Ag sandwich applied to fingermarks and further removed to allow Raman imaging of artificially-contaminated fingermarks (i.e., R6G and 4-ATP) [ 473 ], a combination of fingermark lifting (directly from the fingertip or from a surface, using an adhesive enriched with gold NPs) and SERS imaging of artificially-contaminated fingermarks (i.e., R6G and cotinine) [ 474 ], SERS applied to artificially-contaminated fingermarks (i.e., TNT, RDX, PETN) [ 475 ], MALDI-ToF-MSI applied to fingermarks contaminated with plant-derived psychoactive biomarkers [ 476 ], MALDI-MSI applied to spiked fingermarks (i.e., solubilized TNT and medical drug powder) post CA-fuming [ 241 ], an LC-MS method aiming at establishing a cut-off between drug users and environmental contamination [ 477 ], degradation with time of explosives and illicit drugs in fingermarks using FTIR spectroscopy imaging [ 478 ], use of LA-ICP-MSI to image gunshot-related metals in fingermarks [ 479 ], NALDI-MSI, MALDI-MSI and DESI-MSI were compared to image spiked fingermarks (i.e., methamphetamine, cocaine and heroin in solution) [ 480 ], SERS imaging of sebum-rich fingermarks spiked with methamphetamine (i.e., contact with solution) and left on an agarose gel [ 481 ], FT-ICR-MS to identify TATP in secretion residue after explosive handling [ 482 ], electrochemiluminescence to image fingermarks spiked with nicotine and TNT (i.e. solution dropped onto existing latent fingermarks) [ 483 ], SRXRF applied to sunscreen-contaminated fingermarks [ 484 ], antibody-functionalized polystyrene NPs applied to drug-spiked fingermarks (i.e., ketamine and amphetamine in solution on the fingertip) [ 414 ], and MALDI-MSI to image cocaine-contaminated fingermarks left on £5 polymer banknotes [ 427 ] – see section 3.2.19 for details.…”