A method for the rapid screening and determination of amphetamine-type designer drugs in saliva by a novel nib-assisted paper spray-mass spectrometry procedure is described. Under optimized conditions, the limit of detections for amphetamine derivatives (model samples: o-, m-, p-chloroamphetamine and o-, m-, p-fluoroamphetamine, respectively) were determined to 0.1 μg/mL by the nib-assisted paper spray-mass spectrometry method. This method is easier and has a higher sensitivity than similar methodologies, including atmospheric pressure/matrix-assisted laser desorption ionization mass spectrometry and electrospray-assisted laser desorption ionization/mass spectrometry. Data obtained using more classical separation methods, including liquid chromatography and capillary electrophoresis, are also reported.

A novel drug-screening system, consisting of paper spray-MS (PS-MS) and a CE-ESI-MS method was developed. This system can be easily switched either to PS-MS for rapidly screening samples or to the traditional CE-ESI-MS method for separation and to obtain detailed mass spectral information, while sharing the same mass spectrometer. In the former case, when a sharp (15°-tip) chromatography paper was used, the optimized distance from the paper tip to the mass inlet was 7.7 mm, whereas the optimized distance for the CE-ESI tip was ∼13.5 mm. Using 4-chloroamphetamine as a model compound, the LODs for PS-MS and CE-ESI-MS were determined to ∼0.1 and 0.25 ppm, respectively. Comparisons of results obtained using PS-MS and CE-ESI-MS and the experimental conditions are described.