Key Laboratory of Global Change and Marine Atmospheric Chemistry, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005, Fujian, China.
Anal Bioanal Chem. 2022 Aug;414(19):5869-5876. doi: 10.1007/s00216-022-04152-x. Epub 2022 Jun 1.
A simple resorcinol method to determine nitrate (NO) in seawater using a microplate reader with a 48-well plate was established. The method involved the nitration of resorcinol in sulfuric acid to form a pink product that was detected at 505 nm. Reagent concentrations were optimized, and the effect of salinity on NO determination was investigated. The detection limit of this method was 0.8 µM, while the upper limit of the linear range was 100 µM. The recoveries ranged from 91.5 to 109.7% for spiked seawater samples with different salinities. The proposed method was compared with two reference methods, and the results revealed a good correlation. Compared to conventional methods that require the preparation of reactants, the proposed method used aqueous solutions as reagents for the reaction, which was simpler and more convenient. Compared to the methods that used organic solvents for the direct determination of NO, the proposed method was suitable for estuarine and coastal water samples with large salinity variations. All results indicated that the proposed method can satisfy the requirements of laboratory analysis and demonstrate high application potential for use in field determination.
建立了一种使用微孔板读取器和 48 孔板测定海水中硝酸盐（NO）的间苯二酚法。该方法涉及在硫酸中硝化物间苯二酚形成粉红色产物，在 505nm 处检测。优化了试剂浓度，并研究了盐度对 NO 测定的影响。该方法的检测限为 0.8µM，线性范围的上限为 100µM。对于不同盐度的加标海水样品，回收率范围为 91.5%至 109.7%。将所提出的方法与两种参考方法进行了比较，结果显示出良好的相关性。与需要制备反应物的传统方法相比，该方法使用水溶液作为反应试剂，更简单、更方便。与使用有机溶剂直接测定 NO 的方法相比，该方法适用于盐度变化较大的河口和沿海水样。所有结果表明，该方法可以满足实验室分析的要求，并具有在现场测定中应用的高潜力。
