title: A gas chromatographic method of measuring residual water in freeze-dried smallpox vaccine.
abstract: A new method for the accurate determination of residual water in freeze-dried vaccines is described. Tests may be carried out on very small samples in sealed ampoules. The method is based on the adsorption of water from the vaccine with benzene and its estimation by gas chromatography. It appears that the residual water and total nitrogen content are important factors in the stability of the vaccine.
mesh_terms: D002849:Chromatography, Gas; D005612:Freeze Drying; D008722:Methods; D012900:Smallpox Vaccine / Q000032:analysis*; D014867:Water / Q000032:analysis*
chemical_list: D012900:Smallpox Vaccine; D014867:Water