Desorption electrospray ionisation mass spectrometry: A rapid screening tool for veterinary drug preparations and forensic samples from hormone crime investigations

Hormone and veterinary drug screening and forensics can benefit from the recent developments in desorption electrospray ionisation (DESI) mass spectrometry (MS). In this work the feasibility of DESI application has been studied. Using a linear ion trap or quadrupole time-of-flight (TOF) MS instrument both full-scan and data-dependent collision-induced dissociation MSn spectra were acquired in seconds without sample preparation. Preliminary data are presented for the rapid screening of (pro)hormone supplement samples, an illegal steroid cocktail and forensic samples from veterinary drug investigations. The potential of this DESI approach is clearly demonstrated since compounds observed could be independently confirmed by liquid chromatography/TOFMS with accurate mass measurement, and/or proton nuclear magnetic resonance spectroscopy. Specific concerns related to false-positive and false-negative findings due to limitations in quantification and memory-effects are briefly discussed. It is envisaged that DESI will achieve a prominent role in hormone and veterinary drug analysis in the near future.