Note 20 — Chapter XI · URICÆMIA IN GOUT
Reading edition
Criticising the colorimetric method on the ground that “different workers obtain on the same blood samples results which vary considerably,” L. J. Curtman and A. Lehrman have devised a new volumetric method for the determination of uric acid in blood. The following is the summary of their researches:—
(1) An experimental study of a number of metallic salts as precipitants for uric acid in a solution alkaline with sodium carbonate was made. The results showed that nickel is the best of those tried.
(2) A 0·0004 N iodine solution was found suitable for the estimation of small amounts of uric acid provided certain conditions are adhered to.
(3) Based upon the above considerations, a new method has been developed for the determination of uric acid in blood, the chief features of which are (a) the precipitation of the uric acid by means of nickel acetate in a solution alkaline with sodium carbonate. (b) The estimation of the uric acid in the precipitate by means of a dilute solution of iodine.
(4) The method was applied with good results to aqueous solutions of uric acid as well as to blood serum to which known amounts of uric acid were added.
(5) Low and inconsistent results were obtained when the method was applied to sheep’s blood to which known amounts of uric acid were added. This was shown to be due to the inadequacy of the procedure generally employed, for the coagulation and preliminary treatment of the blood. The colorimetric method when used in the analysis of samples of the same blood also gave low and inconsistent results for the same reason.
(6) Comparison tests show that the volumetric method is fully as accurate as the colorimetric method, and possesses the advantage of requiring no special apparatus.