Rapid determination of flunitrazepam in alcoholic beverages by desorption electrospray ionization-mass spectrometry

Desorption electrospray ionization-mass spectrometry (DESI-MS), a novel ambient ionization technique, was used in this study for determining flunitrazepam in various alcoholic beverages. Using this technique, no pretreatment of the samples was necessary and identification of the drug was accomplished in individual samples in minutes. In addition, the acquired mass spectra provide the information of the identity of the drink based on the detected characteristic ions from the matrices. This study also demonstrates the capability of DESI-MS to perform quantitative analysis of simulated evidence samples with a limit of quantification of 3μg/mL. Furthermore it has been shown that this method can be used for high-throughput analysis whereby six samples were analyzed in a row within 6 minutes and no observable sample carry-over was noted. DESI-MS shows potential as a rapid, sensitive, and selective technique for forensic analysis of spiked beverages which are typical evidence of drug facilitated sexual assault and robbery cases.