Identification and Quantitation of Amphetamines, Cocaine, Opiates, and Phencyclidine in Oral Fluid by Liquid Chromatography—Tandem Mass Spectrometry
Abstract
Analytical methods for measuring multiple licit and illicit drugs and metabolites in oral fluid require high sensitivity, specificity, and accuracy. With the limited volume available for testing, comprehensive methodology is needed for simultaneous measurement of multiple analytes in a single aliquot. This report describes the validation of a semi-automated method for the simultaneous extraction, identification, and quantitation of 21 analytes in a single oral fluid aliquot. The target compounds included are amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxy-amphetamine, 3,4-methylenedioxyethylamphetamine, pseudoephedrine, cocaine, benzoylecgonine, codeine, norcodeine, 6-acetylcodeine, morphine, 6-acetylmorphine, hydrocodone, norhydrocodone, dihydrocodeine, hydromorphone, oxycodone, noroxycodone, oxymorphone, and phencyclidine. Oral fluid specimens were collected with the Intercept device and extracted by solid-phase extraction (SPE). Drug recovery from the Intercept device averaged 84.3%, and SPE extraction efficiency averaged 91.2% for the 21 analytes. Drug analysis was performed by liquid chromatography-tandem mass spectrometry in the positive electrospray mode using ratios of qualifying product ions within +/-25% of calibration standards. Matrix ion suppression ranged from -57 to 8%. The limit of quantitation ranged from 0.4 to 5 ng/mL using 0.2 mL of diluted oral fluid sample. Application of the method was demonstrated by testing oral fluid specimens from drug abuse treatment patients. Thirty-nine patients tested positive for various combinations of licit and illicit drugs and metabolites. In conclusion, this validated method is suitable for simultaneous measurement of 21 licit and illicit drugs and metabolites in oral fluid.