Abstract
On the determination of molybdate by polarograph, we found out that the phosphoric acid of 15-70% gave the most ideal polarogram of molybdate as the supporting eletrolyte. So we studied on the undireet method, that is the determination of excess molybdate which was contained in the supernatant solution on the ammonium molybdate method. On this supporting electrolytes, the height of wave as proportionate to the concentration of molybdate.Although the first wave was affected by cl ion, the second wave was not affected by any ion. Therfore we adopted the second wave for the determination of molybdate and used 50% phosphoric acid as supporting electrolyte. This method was examined to the determination of phosphoric acid in fertilizers and a desirable results were obtained.
