New gas chromatogrphic assay for the quantification of methadone. Application in human and animal studies.
A new gas chromatographic assay utilizing 2-dimethylamino-4,4-diphenyl-5-nonanone as the internal standard was developed for the quantification of methadone. The method involved extraction of methadone with 1-chlorobutane from tissue at pH 9.8, re-extraction of an aliquot of the organic solvent with 0.5 M sulphuric acid, alkalinization and final extraction into chloroform. The assay was used to determine the concentration of methadone (i) in whole blood samples from a normal volunteer following a single 9.4-mg oral dose of d-methadone hydrochloride, (ii) in whole blood, saliva and gastric juice from a methadone addict maintained on 90 mg of dimethadone hydrochloride per day, (iii) in mouse liver microsomes incubated with methadone, and (iv) in the perfusate of the isolated perfused rat liver.
D000818:Animals; D002849:Chromatography, Gas; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008099:Liver / Q000032:analysis / Q000378:metabolism; D008297:Male; D008691:Methadone / Q000032:analysis* / Q000378:metabolism; D008722:Methods; D051379:Mice; D008862:Microsomes, Liver / Q000032:analysis / Q000378:metabolism; D051381:Rats; D012995:Solubility; D013237:Stereoisomerism; D019966:Substance-Related Disorders / Q000378:metabolism; D013997:Time Factors
D008691:Methadone