Analytical methods have been developed for the determination of cyanate esters and imidocarbonates, the active species present on CNBr-activated polysaccharide resins. Imidocarbonates are determined by selective acid hydrolysis followed by determination of the liberated ammonia by a modification of the ninhydrin reaction. Cyanate esters are determined by a spectrophotometric procedure based on the reaction with pyridine and employing N,N'-dimethylbarbituric acid as a color-forming reagent. For the determination of the coupling capacity, a procedure is suggested which allows the amount of coupled ligand to be determined directly on the resin and without prior hydrolysis. Using those procedures it was found that the coupling capacity of activated resins toward small ligands can be predicted by determining the amounts of cyanate esters and imidocarbonates present on the resin, and that cyanate esters are predominantly responsible for coupling of ligand to activated Sepharose.
All Science Journal Classification (ASJC) codes
- Molecular Biology