Office of the Armed Forces Medical Examiner, Division of Forensic Toxicology, Armed Forces Institute of Pathology, Washington, D.C., USA
* Varian Chromatography Systems, Walnut Creek, CA, USA

To that end, a gas chromatography/tandem mass spectrometry (GC/MS/MS) method was developed using an internal ionization ion trap MS for the detection of underivatized LSD. Following solid phase extraction of 5mL of urine, extracts are injected into a temperature-programmable injector with a 0.5mm I.D. direct-injection insert. The injection port is optimized to reduce analyte loss by injecting at low temperatures followed by rapid heating. Collision-induced dissociation (CID) of the isolated 323 m/z parent ions of LSD and lysergic acid methylpropylamide (LAMPA, internal standard) is achieved by resonant dissociation for 30msec at 0.61v. The product ions 280, 222, and 196 m/z are monitored for both LSD and LAMPA with 222 m/z as the quantifying ion.

The method was linear over the concentration range 20-2000 pg/mL with a correlation coefficient of 0.999. The observed limit of detection was 20 pg/mL with an 80 pg/mL limit of quantitation. Intra-day stability assessed over 12 injections gave a %CV=5.0. The method was successfully applied to both DoD Quality Control Laboratory samples and previously confirmed LSD positive samples.

Ion trap MS/MS has been demonstrated as a favorable tool for low level drug confirmation in biological samples. It provides the necessary sensitivity with lower complexity of operation over alternate instrumental methods.