锌镉还原法的海水硝酸盐浓度

按照《海洋调查规范》(1991)中锌镉还原法 ,用三对基体来配制NO3 -标准溶液 :NaCl水 (31gNaCl加纯水至 1L)与无氮东海海水ECS、《海洋调查规范》(1991)人工海水SAS(NaCl水加MgSO4)与ECS和Strick land Parsons(1972 )人工海水SP72 (SAS加NaHCO3 )与ECS。经测定 ,且忽略标准曲线方程的截距 ,纯水与ECS的NO3 -还原率比为 0 .2 6 6 ,NaCl水与ECS的比为 0 .70 6 ,SAS与ECS的比为 0 .90 1,而SP72与ECS的比则为1.0 0 9。显然 ,用ECS和等价的SP72定出的值最接近天然海水中NO3 -的浓度。由《海洋调查规范》(1991)SAS定出的浓度须乘上 0 .90 1～ 0 .95 6后才接近海水中NO3 -浓度。

Nitrate concentration in seawater by zinc cadmium reduction method

By the zinc cadmium reduction method of China National Specifications, NO 3-N standard solution was made in pair the nitrate working calibration equations of NaCl water, or Specification's artificial seawater (SAS as NaCl water plus MgSO 4), or Strickland-Parsons'artificial seawater (SP72 as SAS plus NMaHCO 3), to low-nutrient East China Sea seawater (ECS). If calibration equation's intercept is neglected, the ratio of the reduction efficiencies between pure water and ECS matrix is 0.266; between NaCl water and ESC is 0.706; between SAS and ECS is 0.901; between SP72 and ECS reaches 1.007. Since the concentration from low-nutrient ECS's approaches the natural one, the SP72 is equivalent to the ECS. Multiply the concentration from SAS by at least 0.901, thus getting the nitrate value of the closer natural one.