A simple method to detect contaminating peptides and amino acids in large-scale ganglioside preparations

A reverse-phase liquid chromatography method was developed to analyse the presence of contaminating peptides and amino acids in large-scale monosialoganglioside preparations. Samples were hydrolysed under controlled conditions and derivatized with phenylisothiocyanate. PTC-amino acids were then separated and identified by HPLC. The sensitivity of the method allowed detection of a least 50 pmoles of amino acid per mg of ganglioside with excellent reproducibility and little or no interference of by-products derived from hydrolysis of the glycosphingolipid. The response was consistently linear for each amino acid within the examined analytical range. The ease and speed of performance make this method a useful tool for rapidly monitoring large-scale extraction and purification processes of biologicals obtained from natural sources.