Grades sulfur hexafluoride

Cyclohexane and benzene (Fisher spectranalyzed grade) and nitrous oxide and sulfur hexafluoride (Matheson) were used as supplied. The samples were thoroughly freed from dissolved air and frozen into the cells on a grease and mercury-free vacuum line. Hydrogen and nitrogen were measured using conventional vacuum line techniques and a mass spectrometer. Cyclohexene and bicyclohexyl were determined by gas liquid chromatography (16). 

Sulfur hexafluoride is available for commercial and industrial use in various grades (minimum 99.8 mole percent) having much the same component proportions from one producer to another. 

Sulfur hexafluoride is made commercially by the direct fluorination of molten sulfur. Some higher and lower toxic fluorides formed in the process are removed, and the commercial product is more than 99.5 mole percent pure. A high-purity etchant grade is also available for the electronics industry. Common impurities include small amounts of carbon tetrafluoride, nitrogen, and water vapor. 

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