The determination of thebaine in Papaver bracteatum Lindl by gas-liquid chromatography

Several solvents have been examined in the process of developing a convenient method for extracting powdered material and removing interfering pigments to produce an extract of Papaver bracteatum suitable for g.l.c. assay. The most suitable extracting solvent was aqueous acetic acid (5%); the assay method gave satisfactory reproducibility with a wide range of plant materials (coefficient of variation 0.63 to 3.33%). The accuracy was checked by recovery experiments with pure thebaine and by examination of exhausted marcs. The presence of other alkaloids did not interfer with the assay. There were substantial differences in the amounts of thebaine extracted from capsule and root samples by ammoniacal methanol and by aqueous acetic acid, indicating the presence of thebaine in a "bound" form. The minimum amount of thebaine that could readily be determined by the g.l.c. method was 0.3 mg in the sample of powder used for the assay.