title: Use of refractometry to determine nitrogen accumulation in close d circuits.
abstract: We have described a technique by which a portable interference refractometer may be used to determine the accumulation of nitrogen in a totally closed anaesthetic circuit. The inspired mixture contained halothane, oxygen, nitrous oxide and nitrogen. The concentrations of the first two were controlled with u.v. paramagnetic analysers respectively. It was then possible to determine the percentage of nitrous oxide replaced by nitrogen by measuring the refractive power of the mixture.
mesh_terms: D000776:Anesthesiology / Q000295:instrumentation*; D004578:Electron Spin Resonance Spectroscopy; D006221:Halothane / Q000032:analysis; D006813:Humidity; D008722:Methods; D009584:Nitrogen / Q000032:analysis*; D009609:Nitrous Oxide / Q000032:analysis; D010100:Oxygen / Q000032:analysis; D011312:Pressure; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature
chemical_list: D009609:Nitrous Oxide; D009584:Nitrogen; D010100:Oxygen; D006221:Halothane