Separation of silicon and phosphorus with ammonium molybdate and their successive determination

Abstract

A method for the successive determinations of silicon and phosphorus is described. Phosphate is separated cleanly from silicate as ammonium molybdophosphate; phosphate in the precipitate and silicate in the filtrate are determined by conventional quinoline procedures. The method is suitable for the separation and determination of 0·2 to 2 mg of each of the ions. The separation method can be applied to organic materials, after decomposition with peroxide. A study of organic bases for the precipitation of molybdosilicate showed that none is preferable to quinoline.