The detection and quantification of lorazepam and its 3‐O‐glucuronide in fingerprint deposits by LC‐MS/MS

Abstract

The use of fingerprints as an alternative biological matrix to test for the presence of drugs and/or their metabolites is a novel area of research in analytical toxicology. This investigation describes quantitative analysis for the benzodiazepine lorazepam and its 3-O-glucuronide conjugate in fingerprints following the oral administration of a single 2 mg dose of lorazepam to five volunteers. Creatinine was also measured to investigate whether the amount of drug relative to that of creatinine would help to account for the variable amount of secretory material deposited. Fingerprints were deposited on glass cover slips and extracted by dissolving them in a solution of dichloromethane/methanol, containing tetradeuterated lorazepam as an internal standard. The samples were evaporated, reconstituted with mobile phase and analysed by LC-MS/MS. Chromatography was achieved using an RP (C18) column for the analysis of lorazapem and its glucuronide, and a hydrophilic interaction column (HILIC) for the analysis of creatinine. Lorazepam and its glucuronide were only detected where ten prints had been combined, up to 12 h following drug administration. In every case, the amount of lorazepam glucuronide exceeded that of lorazepam, the peak amounts being 210 and 11 pg, respectively. Adjusting for creatinine smoothed the elimination profile. To our knowledge, this represents the first time a drug glucuronide has been detected in deposited fingerprints.

Trends in fingerprint analysis

“…It has also been used to detect lorazepam in fingerprints from healthy volunteers that were given oral doses of lorazepam. The results of this study showed that the appearance of the drug in the fingerprint content was directly caused by the intake of the drug [29]. Also, one of the more recent techniques, MeV-SIMS, has been used for fingerprint imaging as well.…”

DNA Fingerprints: Advances in their Forensic Analysis Using Nanotechnology

“…Techniques such as mass spectroscopy in addition to chromatography are used to identify the molecular ion of explosive residues or prohibited drugs important for forensic detection [10]. Other methods used for fingerprint analysis are Surface Assisted Laser Desorption/ Ionization (SALDI) coupled with mass spectroscopy [11], Desorption Electrospray Ionization (DESI) mass spectroscopy [12], Matrix Assisted Laser Desorption/ Ionization mass spectroscopy (MALDI) [13], Raman spectroscopy, Infrared spectroscopy [1].…”

Hydrophilic stationary phases: A practical approach for the co‐analysis of compounds with varying polarity in biological matrices

“…Blood from one set of volunteers was collected into heparin tubes, the plasma separated by centrifugation. Single-deposited fingerprints were collected as described previously [4] from another set of volunteers together with urine sampled simultaneously. Plasma, urine and fingerprint residues were stored at À801C, until analysis.…”

“…This HILIC approach may be additionally used in SPE to extract creatinine from plasma and urine, where these complex matrices contain many potential interferents, as also described herein. As an aside, the application of SPE for fingerprint deposits appears not to be necessary, as LC-MS/ MS analysis appears to be relatively successful, subsequent to dissolving the residue in an organic solvent, then evaporation and reconstituting in a mobile phase [4].…”

“…The blood concentration of creatinine is maintained within narrow limits, and creatinine is excreted at a constant rate, and thus it is an indicator of the glomerular filtration rate of the kidney [3]. Apart from compensating for varying urinary volume in un-timed urine samples, where a ratio of the concentration of a drug and/or metabolite to creatinine may be calculated, there is some indication that such a ratio may also apply in the analysis of drugs in sweat deposited as fingerprints [4]. The concentration of drugs and their metabolites in an extract of a deposited fingerprint is far less than in blood and urine, hindering multiple analysis as the extract volume has to be kept small in order to maintain sufficient concentration for detection.…”