Determination of Uric Acid: an Automated Analysis Based on a Carbonate Method.

VARIETY of methods is available for tue colorimetric determination of uric acid. In general, these are based on precipitation of proteins, followed by the reduction in an alkaline medium of phosphotungstate by the uric acid ill the protein-free filtrate. Results of colorimetric determinations may at times vary from “true” uric acid values as determined by unease methods. This is because the colonimetric methods of analysis are subject to both positive and negative errors. Positive errors arise because colonimetric methods are not specific for uric acid and are influenced by nonuric acid reducing substances present in serum. Negative errors are the result of variable losses of uric acid during precipitation of serum proteins prior to color development. The purpose of this paper is to describe an automated colorimetric method for the determination of uric acid, based on a carbonate metli0(1. In this method, uric acid is sepal’ated from proteills by dialysis, thereby avoiding loss of uric acid incident to pi’ecijitatioll of proteins.