Comparison Study of Commonly Used Seawater Nitrate Determination Methods
At present,more and more attention has been paid to the problems of Marine ecological environment.Nitrogen and phosphorus have become the main substances exceeding the standard of Marine ecological water bodies,among which seawater nitrate is one of the most important form of inorganic nitrogen.In order to select suitable monitoring methods in seawater monitoring work and ensure the authenticity and accuracy of nitrate monitoring data,the paper compares the cadmium column reduction method,zinc cadmium reduction method and flow analysis method used in daily work to determine nitrate in seawater.The conclusion is that the zinc-cadmium reduction method is not recommended.If it is necessary to use,the optimized ammonium zinc-cadmium reduction method can be selected,and the method should be verified before use.Cadmium column reduction method is a commonly used method,which has complicated operation steps,long determination process and low operation and maintenance cost,and is suitable for the determination of a small number of samples.Flow analysis method is recommended as the preferred method at present,which has high sensitivity,simple operation and high operation and maintenance cost,and is suitable for the determination of a large number of routine samples.
nitrate nitrogencadmium column reductionzinc and cadmium reductionflow analysisecological environmentmarine chemical industry