Rapid screening of abused drugs by direct analysis in real time (DART) coupled to time-of-flight mass spectrometry (TOF-MS) combined with ion mobility spectrometry (IMS)

- A method based on non-radioactive DAPP-IMS and DART-TOFMS was first described.
- The method screen abused drugs less than 2 min with minimal sample pretreatment.
- A standardized screening procedure was built with criteria to detect abused drugs.
- The method was successfully applied to 50 actual seized drug samples.

Increasing in cases involving drugs of abuse leads to heavy burden for law enforcement agencies, exacerbating demand for rapid screening technique. In this study, atmospheric pressure ionization technologies including direct analysis in real time (DART) ion source coupled to a time-of-flight mass spectrometer (DART-TOF-MS)as well asdopant-assisted positive photoionization ion mobility spectrometry (DAPP-IMS) without radioactivity were utilized together as the powerful analytical tool for the rapid screening and identification of 53 abused drugs.The limits of detection (LOD) were 0.05-2 μg/mL when using DART-TOF-MS and 0.02-2 μg when using DAPP-IMS which could satisfy the actual requirement in forensic science laboratory. The advantages of this method included fast response, high-throughput potential, high specificity, and minimal sample preparation. A screening library of reduced mobility (K0), accurate mass of informative precursor ion ([M+H]+) and fragment ions was established respectively by employing a bench-top DAPP-IMS and TOF-MS in-source collision induced dissociation (CID) mode. Then the standardized screening procedure was developed with criteria for the confirmation of positive result. A total of 50 seized drug samples provided by local forensic laboratory we reanalyzed to testify the utility of the method. This study suggests that a method combing DART-TOF-MS and DAPP-IMS is promising for the rapid screening and identification of abused drugs with minimal sample preparation and absence of chromatography.