Liu T Z, Khayam-Bashi H
Clin Chem. 1979 May;25(5):788-90.
We report the effect of major catecholamine metabolites such as homovanillic acid and vanilmandelic acid, normally present in urine, on quantitation of urinary uric acid by the direct acid ferric-reduction procedure [(Am. J. Clin. Pathol. 60, 691 (1973)]. When aqueous uric acid standards containing a mixture of these two metabolites, in concentrations comparable to those in a normal human 24-h urine, were added to Fe3+-phenanthroline or Fe3+-2,4,6-tripyridyl-s-triazine reaction mixture, the resulting absorbances at 505 or 593 nm considerably exceeded those of standards without such additions. Moreover, quantitation of urinary uric acid by the direct acid ferric-reduction procedure gave values that significantly exceeded those determined by the uricase method. Interference by the two metabolites was eliminated by extracting urine specimens with ethyl acetate before quantitation. Spectral scans revealed that homovanillic acid or vanilmandelic acid alone could also effectively reduce Fe3+-chelator complex and that the effect of these compounds on the analytical reaction was additive.
我们报告了尿中通常存在的主要儿茶酚胺代谢产物如高香草酸和香草扁桃酸，对采用直接酸铁还原法（《美国临床病理学杂志》60, 691 (1973)）定量测定尿尿酸的影响。当向Fe³⁺ - 邻菲罗啉或Fe³⁺ - 2,4,6 - 三吡啶基 - s - 三嗪反应混合物中加入含有这两种代谢产物混合物的尿酸水溶液标准品，其浓度与正常人24小时尿液中的浓度相当，在505或593 nm处得到的吸光度显著超过未添加此类物质的标准品的吸光度。此外，采用直接酸铁还原法对尿尿酸进行定量测定得到的值显著超过用尿酸酶法测定的值。在定量前用乙酸乙酯萃取尿标本可消除这两种代谢产物的干扰。光谱扫描显示，单独的高香草酸或香草扁桃酸也能有效还原Fe³⁺ - 螯合剂络合物，并且这些化合物对分析反应的影响是相加的。
