title: Gas chromatographic analysis and storage of gas samples from the middle ear.
abstract: Methods for storage and analysis of gas samples were studied prior to measuring the composition of gas in the human middle ear cavity. Storage and analysis of gas samples are beset with several pitfalls. The dead space of the sampling syringe must be considered and the gas sample can equilibrate with the surrounding atmosphere, especially if the analysis cannot be done immediately. In this study the equilibration rate was found to fit an exponential function with a time constant of 0.004 min-1. The time constant was reduced by more than a factor of ten when butyl rubber stoppers were used to seal the syringes. Silicone rubber stoppers were less efficient. Disposable plastic syringes were found just as efficient as 'gas-tight' syringes.
authors.affiliation: Institute of Biochemistry, Odense University, Denmark.
authors.forename: L
authors.initials: L
authors.lastname: Jørgensen
authors.forename: A
authors.initials: A
authors.lastname: Møller
authors.forename: A
authors.initials: A
authors.lastname: Grøntved
mesh_terms: D002849:Chromatography, Gas / Q000379:methods*; D004432:Ear, Middle / Q000032:analysis*; D005740:Gases / Q000032:analysis*; D006801:Humans; D010313:Partial Pressure; D013048:Specimen Handling / Q000379:methods; D013594:Syringes; D014618:Vacuum
chemical_list: D005740:Gases