Detection of drugs in lifted cyanoacrylate-developed latent fingermarks using two laser desorption/ionisation mass spectrometric methods.

This paper describes a method for lifting cyanoacrylate (CNA)-developed latent fingermarks from a glass surface and the detection of five drugs in lifted marks from fingers that had been in contact with the drugs, using Surface Assisted Laser Desorption Ionisation Time of Flight Mass Spectrometry (SALDI-TOF-MS) or Matrix Assisted Laser Desorption Ionisation TOF-MS (MALDI-TOF-MS). Two drugs of abuse (cocaine and methadone) and three therapeutic drugs (aspirin, paracetamol and caffeine) were used as contact residues. Latent fingermarks spiked with the drugs were subjected to CNA fuming followed by dusting with ARRO SupraNano™ MS black magnetic powder (SALDI-TOF-MS) or 2,5-dihydroxybenzoic acid (DHB) (MALDI-TOF-MS).

Detection of nitro-organic and peroxide explosives in latent fingermarks by DART- and SALDI-TOF-mass spectrometry.

The ability of two mass spectrometric methods, surface-assisted laser desorption/ionization-time of flight-mass spectrometry (SALDI-TOF-MS) and direct analysis in real time (DART-MS), to detect the presence of seven common explosives (six nitro-organic- and one peroxide-type) in spiked latent fingermarks has been examined. It was found that each explosive could be detected with nanogram sensitivity for marks resulting from direct finger contact with a glass probe by DART-MS or onto stainless steel target plates using SALDI-TOF-MS for marks pre-dusted with one type of commercial black magnetic powder. These explosives also could be detected in latent marks lifted from six common surfaces (paper, plastic bag, metal drinks can, wood laminate, adhesive tape and white ceramic tile) whereas no explosive could be detected in equivalent pre-dusted marks on the surface of a commercial lifting tape by the DART-MS method due to high background interference from the tape material.

Separation of fingerprint constituents using magnetic silica nanoparticles and direct on-particle SALDI-TOF-mass spectrometry.

Two types of amorphous, silica nanoparticles have been produced and used as surface assisting agents during laser desorption/ionisation time-of flight-mass spectrometry (SALDI-TOF-MS). The first is hydrophilic possessing surface aminopropyl groups and the second hydrophobic containing surface phenyl groups. Each particle type acts as a solid phase adsorbent, adsorbing analytes according to their charge and hydrophobicity.

Doped amorphous silica nanoparticles as enhancing agents for surface-assisted time-of-flight mass spectrometry.

This article examines the use of doped amorphous silica nanoparticles for surface-assisted laser desorption/ionisation-time of flight-mass spectrometry (SALDI-TOF-MS) of hydrophilic and hydrophobic compounds. A range of particles with surface aliphatic carboxylic, aminophenyl, phenyl or aminopropyl groups have been produced and these have been doped with carbon black, polyaniline or graphite. The effects of surface groups and dopants on the laser desorption/ionisation process were studied.

Environmental nicotine contamination in latent fingermarks from smoker contacts and passive smoking.

Hydrophobic silica nanopowder has been used as an effective latent fingermark development agent and subsequently as an enhancement agent in the surface-assisted laser desorption/ionisation-time of flight (SALDI-TOF) mass spectrometry for analysis of fingermark components. The technique has been used in the detection of nicotine and cotinine in the fingermarks of smokers. In order to have confidence in concluding that the nicotine in such samples is indicative of cigarette usage, it is necessary to establish that contamination by environmental contact or from hand to hand contact with smokers or from passive smoking does not lead to false identification of non-smokers as smokers.