Abstract:

A new method is described for following the inhibitory effect in artificial urine of polymeric dicarboxylic amino acids and other polyanionic derivs. on Ca oxalate crystn. The technique is based on using a Ca-specific electrode to measure Ca++ ion activity in soln. to assess the formation of Ca oxalate ppt. The retardation effect of poly-L-glutamic acid Na salt and poly-L-aspartic acid Na salt occurred in a 5-100 ppm concn. range. Blocking of the free carboxylic groups on the polymers eliminated the retardation effect. The retardation appears to be an inhibition of seed crystal growth rate. Normal urine retarded the pptn. but pathol. urine did not. [on SciFinder(R)]