Feasibility of using an automated colorimetric procedure for the determination of seawater nitrate in the 0 to 100 nM range: Examples from field and culture

An automatic colorimetric procedure for measuring nanomolar quantities of nitrate and nitrite in seawater has been improved in sensitivity. Application of this method toin situ investigations in the North Atlantic Ocean in January 1989 and algal culture (Skeletonema costatum) experiments in the laboratory demonstrated that one can record concentrations in the 0 to 100 nM range using classical Technicon AutoAnalyzer equipment. In this working range highest precision obtained was ±2.87 and ±1.24 nM for nitrate and nitrite, respectively.