Simultaneous determination of 18 psychoactive agents and 6 metabolites in plasma using LC-MS/MS and application to actual plasma samples from conscription candidates.

In Korea, an increasing number of people attempt to evade military conscription by posing as mental health patients. To verify the authenticity of mental illness, there is a need to detect wide range of psychoactive agents in biological specimens of conscription candidates. In this study, we developed and validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous determination of 18 psychoactive agents and 6 metabolites in human plasma. The method was characterized by the use of a simple, fast and cheap protein precipitation as sample preparation, a rapid run time (11min) and a low volume of plasma sample (200μL). The analytes were monitored under the scheduled multiple reaction monitoring (sMRM) positive and negative mode using electrospray ionization (ESI). The essential validation parameters including selectivity, linearity, accuracy, precision, matrix effect and recovery were satisfactory. The limit of detection ranged from 0.0005 to 0.001μg/mL, and limit of quantitation ranged from 0.005 to 0.025μg/mL. The developed method was successfully applied to 323 actual plasma samples submitted by Korea central physical examination center of military manpower administration in 2016, and is expected to contribute to the rapid and accurate disposition of military service.