Gas-chromatographic measurement of codeine and norcodeine in human plasma.

A gas-chromatographic method is described for determination of codeine and norcodeine in human plasma. The method is specific, sensitive, and precise. It was developed for use in bioavailability studies of therapeutic doses of codeine sulfate. After ingestion of a 60-mg codeine sulfate tablet, mean peak codeine concentration in plasma was 107 mug/liter at 1.0 hour. No measurable concentration of norcodeine was found in the plasma by this method.