Optimization of the hydrolysis of freshwater polysaccharides

Three techniques of acid hydrolysis are verified for their ability to effic iently hydrolyse freshwater polysaccharides. Polysaccharides isolated from two eutrophic lakes were hydrolysed rapidly as compared to model or marine polysaccharides. No single technique is 100% satisfactory for all polysacch arides (i.e. complete hydrolysis with no degradation). Hydrolysis by 0.1 M HCl appeared to give the best results while acceptable results were also ob tained for 1.2 M H2SO4. The results suggest that it is prudent to hydrolyse freshwater polysaccharides under the least drastic conditions and for as s hort of a time as possible in order to minimize decomposition of the sample , (esp. uronic acids). Interferences due to humic acids did not appear to i ncrease as a function of hydrolysis time.