Rapid Identification of Psychoactive Drugs in Drained Gastric Lavage Fluid and Whole Blood Specimens of Drug Overdose Patients Using Ambient Mass Spectrometry.

Psychoactive drug overdoses are life-threatening and require prompt and proper treatment in the emergency room to minimize morbidity and mortality. Prompt identification of the ingested psychoactive drugs is challenging, since witness recall is unreliable and patients' symptoms do not necessarily explain their loss of consciousness. Gas and liquid chromatography mass spectrometric analyses have been the traditionally employed methods to detect and identify abused substances; however, these techniques are time-consuming and labor-intensive. In this study, thermal desorption electrospray ionization mass spectrometry, an ambient mass spectrometric technique, was applied to rapidly characterize flunitrazepam, lysergic acid diethylamide, and 3,4-methylenedioxy-methamphetamine in drained gastric lavage fluid, and ketamine, cocaine, amphetamine and norketamine in whole blood samples. No pretreatment of the gastric lavage fluid specimens was required and the entire analytical process took less than 30 s per specimen. Liquid-liquid extraction, followed by centrifugation, was performed on the whole blood samples. The corresponding compounds were identified through matching the obtained mass spectrometric data with those provided by commercial databases. The limits-of-detection of the tested drugs in both drained gastric lavage fluid and whole blood samples are at sub ppm levels. This is sensitive enough for emergency medical application, since the quantities of medications ingested by overdosed abusers are much higher than the amounts that were tested.