Detection of glycosaminoglycans as a copper (II) complex in capillary electrophoresis

Glycosaminoglycans including heparin, heparan sulfate, chondroitin sulfate, dermatan sulfate and hyaluronic acid were analyzed by reversed polarity capillary electrophoresis. Detection was achieved at 240 nm based on the formation of a copper (II) complex in copper sulfate solution at low pH. Glycosaminoglycans having a high ratio of iduronic acid to glucuronic acid, as well as ones having lower molecular weight, gave the highest detection sensitivity using this method. Detection of the copper (II)-heparin complex is extremely sensitive, permitting the analysis of as little as 10^-9 g. This method was also successfully applied to the analysis of heparin oligosaccharides that lacked a chromophore prepared from heparin using controlled, low pH nitrous acid depolymerization.