Rapid method for quantitative determination of propoxyphene in serum by gas-liquid chromatography.

Rapid, accurate, and precise gas-chromatographic methods are reported for measurement of propoxyphene (“Darvon”) in serum. A sample of 5 ml of serum is required for quantitation in blood after a therapeutic dose of 130-195 mg of propoxyphene; in cases of overdose of propoxyphene, only 1 ml of serum is required in a “toxic method” variation. Neither serum from healthy controls or from hospitalized patients contains interfering substances. Several commonly used analgesic and sedative drugs, added to a serum pool, also did not interfere.Day-to-day precisionof the therapeutic method, as measured by the coefficientof variation (CV), is 7%; the CV for the method as applied to overdose cases is less than 3%. Propoxyphene added to serum could be about 86% accounted foranalytically.