Comparison of high-pressure liquid chromatography (HPLC) and Griess reagent-spectroscopic methods for the measurement of nitrate in serum from healthy individuals in the Nordic countries

Bioavailability of NO can be estimated by measuring the concentration of nitrate (NO(3)) in serum. However, the methods used for the measurement NO(3) in plasma or serum show a great degree of variation. Therefore, we compared two analytical methods for the measurement of NO(3) in serum.The concentration of NO(3) in 600 serum samples collected from healthy individuals was determined by the HPLC and by the Griess reagent-spectroscopic method.The concentration of NO(3) in the samples was 29.4+/-16.1 micromol/L and 26.2+/-14.0 micromol/L (mean+/-SD) measured by HPLC and Griess reagent-spectroscopic method respectively (p0.0001). We detected a significant correlation between the two methods (R=…

Reply to: On the importance of the use of proper approaches for comparison of analytical methods for serum nitrate and evaluation of reference concentrations. By Dr. Dimitrios Tsikas and Dr. Jens M Hohlfeld