ZINCON指示薬と自動光度滴定装置によるサンゴ礁海水中のカルシウム濃度の精密測定

概要

論文の詳細を見る
The carbonate chemistry plays an important role in the carbon cycle, but still not specified quantitatively. To know the change and cycle of calcium concentration is essential to the oceanic carbonate chemistry. A high precision titration method using Zincon indicator reagent and an autooptical sensor was used for the determination of concentration of calcium in sea water. The optimal conditions for the determination was examined. It was found that for the highest precision titration, better than ± 0.05% for 10.20mmol Ca l^<-1> in sea water, the best pH is 9.76 to 9.84 and the amount of Zincon is 0.5 to 0.7ml. The end point of this method was determined by an optical sensor with a filter of 620nm. This method was applied to sea water samples taken around a coral reef in Miyako Island. The temporal change of calcium concentration was observed to range from 9.98 to 10.2 mmol Ca l^<-1>. The lower concentration of calcium in coral reef waters was found during day time. It was confirmed that the present method provides precise data of calcium concentration in sea water.
日本地球化学会の論文
1997-08-04