Electron-capture gas chromatography of methadone after oxidation to benzophenone

✍ Scribed by Per Hartvig; Barbro Näslund

• Book ID: 104145578
• Publisher: Elsevier Science
• Year: 1975
• Tongue: English
• Weight: 553 KB
• Volume: 111
• Category: Article
• ISSN: 1873-3778
• DOI: 10.1016/s0021-9673(00)99284-7

✦ Synopsis

A procedure for the determination of low levels of methadone (6-dimethylamino-4,4-diphenylheptanone-3) in serum has been developed. Methadone is extracted from serum into n-heptane and re-extracted into an acidic aqueous phase. Methadone is oxidized to benzopheone with barium peroxide in sulphuric acid, during which procedure an n-heptane phase is present into which the oxidation product is continuously extracted. The benzophenone formed is determined by means of electron-capture gas chromatography. The recoveries are 100 +/- 3% and 100 +/- 4.5% at the 120 and 16 ng levels, respectively. The minimum amount that can be determined in 1 ml of serum is 4 ng. Interferences from possible metabolies are probably minor. The main cyclic metabolite is only co-determined to a minor extent if the oxidation time is optimized. Comparison of this oxidation method with a combined gas chromatographic-mass spectrometric determination with selected ion monitoring showed identical serum levels.