簡単な尿中蓚酸の測定法

Abstract

Oxalate is a major constituent of more than two-thirds of urinary stones, but because of difficulty and complexity in measuring urinary oxalate, it has not been extensively studied. A simple colorimetric method for measuring urinary oxalate is developed, modifying Snell and Snell's qualitative method. Oxalate is reduced to glyoxylate with zinc and hydrochloric acid and glyoxylate is determined by reaction with phenylhydrazine hydrochloride and subsequent oxidation with potassium ferricyanide to give a red-coloured formazan, which is measured colorimetrically at 530mµ. Potassium ferricyanide is used instead of hydrogen peroxide because the colour fades rapidly with the latter. The average excretion of urinary oxalate in non-urolithiasis patients was 31.3± 11.0 (Mean±S.D.) mg/day. Oxalate recovery was 90.2±13.0% (Mean±S.D.). Other similar compounds except glyoxylate did not react with this method. We think that this simple method for determination of urinary oxalate is reliable and useful for routine laboratory examination.