Chemical depolymerization of dextran sulfate sodium—the application of size‐exclusion or ion‐pair liquid chromatography

We reported previously a method for the separation and quantification of sulfated polysaccharides, dextran sulfate sodium (DSS), using fluorometric labeling and size-exclusion chromatography (SEC). In the present study, we evaluated chemical depolymerization of DSS. In fluorometric analyses using SEC, pyridylamino-DSS (PA-DSS) was depolymerized under acidic conditions, but not under alkaline conditions. In addition, we used ion-pair liquid chromatography (IPLC) and UV analyses for the separation and quantification of sulfate. Sulfate was considerably depleted from DSS under alkaline conditions, but little depleted under acidic conditions. Spectrophotometric studies using toluidine blue revealed that molecular mass is an important factor and a minimum molecular mass of 2500 is needed to induce metachromasia. Fluorometric analyses using SEC and UV analyses using IPLC allow for the detection of DSS, reactants and sulfate.