Doped silica nanoparticles for the detection of pharmaceutical terbinafine in latent fingerprints by mass spectrometry

Abstract

A detailed study on terbinafine excretion in latent fingerprints of a patient prescribed with the medication was carried out for a period of 14 days. Latent fingerprints collected from the patient were dusted with a fingerprint developing agent consisting of magnetized carbon black doped silica nanoparticles and directly analyzed by surface assisted laser desorption ionization-time of flight-mass spectrometry (SALDI-TOF-MS). MS and MSMS spectra of the latent fingerprints confirmed the presence of terbinafine, with the parent ion at m/z 292 and the fragment ion at m/z 141. Coupled with imaging, a gradual increment in the amount of terbinafine detected on the latent fingerprints from day 0 to day 14 was observed. When compared against commonly used 2,5-dihydroxybenzoic acid (DHB), these nanoparticles were more effective as a matrix for MS analysis of terbinafine, recording improved signal-to-noise values. The results demonstrate the efficacy of this technique for the detection of exogenous pharmaceutical drugs in latent fingerprints, providing information pertaining to the donor which may prove useful in cases of smudged prints.