title: A quantitative gas-liquid chromatographic method for the determination of neostigmine and pyridostigmine in human plasma.
abstract: A sensitive and selective analytical method was used to measure the concentration of neostigmine and pyridostigmine in human plasma. The procedure involved preliminary ion-pair extraction of the drugs into dichloromethane, followed by concentration and anlysis of the ion-pair complex using a gas-liquid chromatographic system fitted with a nitrogen detector. Using the peak area ratio technique, pyridostigmine bromide was used as the internal standard for the quantitation of neostigmine in plasma; neostigmine bromide was the internal marker for the determination of pyridostigmine. The method depends on the thermal dequaternisation of the quaternary amines, and can be used to detect 5 ng/ml in a 3-ml plasma sample. Accurate measurement can be made at levels of 50-1000 ng/ml. This assay procedure has been applied to the separate determination of the plasma concentration of neostigmine and pyridostigmine after single administration of intravenous doses in aneasthetised patients.
mesh_terms: D002849:Chromatography, Gas; D002853:Chromatography, Liquid; D006801:Humans; D013058:Mass Spectrometry; D008722:Methods; D009388:Neostigmine / Q000097:blood*; D011729:Pyridostigmine Bromide / Q000097:blood*
chemical_list: D009388:Neostigmine; D011729:Pyridostigmine Bromide