The colorimetric determination of silicate with special reference to sea and natural waters

The optimum conditions for the determination of silicate in natural waters by a molybdenum blue method have been investigated p-Methylaminophenol sulphate has a number of advantages over other reducing agents for the reduction of silicomolybdic acid to molybdenum blue. Beer's law is obeyed up to concentrations of at least 3 mg/l.The interference of several inorganic ions has been investigated; none of those encountered in natural waters is likely to cause error. The method has been applied to the analysis of sea-water and the “salt error” correction evaluated.