Development of a modified copper-cadmium reduction method for rapid assay of total nitric oxide

[摘要] The biomolecule, nitric oxide (NO) is short lived and is converted to two stable products—nitrite (NO2) and nitrate (NO3). NO3 can be measured by colorimetric procedure involving enzymatic conversion to NO2 and by HPLC. But these methods, though sensitive and specific, require expensive reagents or equipment. Reduction of NO3 to NO2 by copper-coated cadmium granules is a popular method devised by Cortas and Wakid (Clin. Chem., 1990, 36, 1440), but it takes 120 min. Our aim of this study is to modify the Cortas and Wakid method for rapid reduction of NO3 to NO2 for total NO estimation in serum. After reduction, NO2 is estimated by Griess reaction. As per our results, complete reduction of NO3 could be achieved by both the methods, but it took only 5 min by our method. Standard graphs were linear by both of the methods. Factors were found to be 143.4 and 196.7 by the Cortas and Wakid method and by our method, respectively. Recovery of NO2 from NO3 was found to be 105% and 106%, respectively. We measured total NO2 in sixteen sera by both the methods and our method's coefficient of correlation was found to be 0.9924. Our method is comparable to that of Cortas and Wakid for complete reduction of NO3 with the greatest advantage of decrease in the time span from 120 to 5 min. This is due to our development of an increased copper coating method on cadmium granules. Our rapid method saves much time for total NO estimation...

[学科分类] 分析化学