Simultaneous LC-MS/MS screening for multiple phenethylamine-type conventional drugs and new psychoactive substances in urine.

New psychoactive substances are being launched in the drug market at a rapidly growing pace. More than 950 new psychoactive substances have been reported to the United Nations Office on Drugs and Crime. The development of new psychoactive substance abuse has drawn risks on public health and safety. Phenethylamines, along with other stimulants, accounted for the majority of the new psychoactive substances being reported in the past decade. This study presents a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous screening of 74 conventional and artificial phenethylamines in urine samples. The chromatographic analysis was performed by a direct dilute-and-shoot procedure using a Phenomenex Kinetex® Phenyl-Hexyl column (10 cm × 2.1 mm i.d., 1.7 µm) and two mobile phases (A: 0.1% formic acid aqueous solution with 5 mM ammonium acetate, B: 0.1% formic acid methanolic solution). The mass fragments were collected under the multiple reaction monitoring mode. The linearity range located in 1.0-50.0 ng/mL for quantitative analysis. The limit of detection and lower limit of quantification for 74 phenethylamines were 0.5 ng/mL and 1.0 ng/mL, respectively. The method was validated and further applied to analyze authentic urine samples. Twenty samples were tested positive of seven phenethylamines from 67 samples, whereas the contents detected were 9.8 ng/mL to 147.1 µg/mL with dilution factors of 40 to 20,000 folds.