Control of components of bacterial polysaccharide vaccines by physical methods

Analysis of polysaccharide components of meningococcal- and pneumococcal vaccines was carried out by proton n.m.r. spectroscopy and gas chromatography. The meningococcal polysaccharides were of high purity but showed differences in degree and position of O-acetylation between manufacturers. The level of contamination of the pneumococcal polysaccharides by C-substance was quantified. These methods provide an alternative to immunological methods for determining serotype and purity.