Rapid and quantitative determination of fentanyls and pharmaceuticals from powdered drug samples by paper spray mass spectrometry.

Paper spray mass spectrometry is presented as a direct, quantitative tool for the measurement of pharmaceutical drugs and a variety of fentanyl analogs in solid samples and powder slurries with the ultimate goal of providing meaningful harm-reduction drug checking. Method development and validation was carried out for fentanyl analog slurries as a proxy for street drug samples. Lower limits of quantitation were determined to be 3.6-7.4 ng/g for fentanyl analogs in the pharmaceutical slurry matrix. Using 1 mg of solid sample, the method can quantify picogram quantities of these drugs, well below required thresholds for even the most potent fentanyl analogs. Quality control samples were prepared and used to assess method validity according to the Scientific Working Group for Forensic Toxicology (SWGTOX) guidelines. Performance metrics for both precision and accuracy were found to be within SWGTOX-recommended guidelines. Additionally, pharmaceutical tablets were used to demonstrate the applicability of the developed paper spray methodology for the direct qualitative and quantitative analysis of active ingredients in pharmaceutical powders deposited directly onto the paper spray substrate. A proposed workflow for rapid solid drug sample measurements is presented with potential applications for point-of-use street drug measurements and other solid sample matrices.