Selected ion monitoring analysis of CP-55,940, a cannabinoid derived analgetic agent

A method is described for the quantification in plasma of CP‐55,940, a new non‐opiate oral analgetic agent, using capillary gas chromatography/mass spectrometry. After extraction, derivation of the drug and a structural analog internal standard is carried out with trifluoracetyl imidazole. The derivative exhibited excellent gas chrornatographic properties. Electron impact yielded an abundant high mass ion whose monitoring permitted the sensitive and specific determination of CP‐55,940 down to 0.5 ng ml−1.