Quantitative determination of C-polysaccharide in Streptococcus pneumoniaecapsular polysaccharides by use of high-performance anion-exchange chromatography with pulsed amperometric detection

Capsular polysaccharides of Streptococcus pneumoniae are used to formulate polyvalent pneumococcal vaccines. A sensitive method, using high-performanc e anion-exchange chromatography with pulsed amperometric detection (HPAEC-P AD), has been developed to quantify the contamination of pneumococcal capsu lar polysaccharides (PnPs) with the C-polysaccharide (C-Ps). As this polysa ccharide is highly immunogenic, and since anti C-Ps antibodies are not prot ective, the need to monitor and reduce its level is of uppermost importance . The method is based on the quantification by HPAEC-PAD of ribitol, which is released by a two-step hydrolysis of the PnPs using aqueous hydrofluoric acid (HF) followed by trifluoroacetic acid hydrolysis (TFA). This simple m ethod has been shown to provide both qualitative and quantitative informati on about the purity of polysaccharide preparations. (C) 2001 Elsevier Scien ce Ltd. All rights reserved.