Research on Flow Injection Analytical Method Suited for Full Automatic Determining Nitrate Nitrogen and Nitrite Nitrogen in Water; general methods of test for pigments: determination of water-soluble sulphates, chlorides and nitrates 适用于全自动在线监测水体中硝酸盐和亚硝酸盐的流动注射分析方法的研究水溶性硫酸盐、氯化物、硝酸盐测定