title: Determination of phenobarbital in human saliva by gas chromatography with electron-capture detection.
abstract: A gas chromatographic method for the determination of phenobarbital in saliva has been developed. Phenobarbital is converted into its bispentafluorobenzyl derivative by extractive alkylation at pH 9 with 0.1 M tetrabutylammonium ion as extracting agent and 0.1 M pentafluorobenzyl bromide as alkylating reagent in methylene chloride. A reaction time of 20 min is required. Quantitation is effected by electorn-capture detection in a gas chromatograph equipped with a pre-column venting system for removal of methylene chloride and pentafluorobenzyl bromide. This procedure allows the direct introduction of the reaction mixture into the gas chromatograph. A 60-ng amount of phenobarbital in 100 mul of human saliva can be determined with a precision of 1.9% (S.D.) and a recovery of 93%.
mesh_terms: D000478:Alkylation; D001965:Bromides; D002849:Chromatography, Gas; D006801:Humans; D007202:Indicators and Reagents; D008722:Methods; D010634:Phenobarbital / Q000032:analysis*; D012463:Saliva / Q000032:analysis*
chemical_list: D001965:Bromides; D007202:Indicators and Reagents; D010634:Phenobarbital