Versatile spectrophotometric method for the determination of silicon.

A versatile spectrophotometric method is described for the determination of microgram levels of silicon, as molybdenum blue. It combines the desirable features of existing spectrophotometric methods with three pretreatment procedures, namely (a) the removal of cations with a cation-exchange resin in the H(+)-form, (b) the conversion of all silicon species into the reactive monomer with an alkaline treatment, and (c) the decomposition of silicon fluoride with boric acid in the presence of cation-exchange resin. These pretreatments coupled with the colour development provide five procedures which are applicable to a wide variety of samples including natural and industrial waters and solutions of various nuclear reactor fuels and components. Provisions are included for the selective determination of total silicon.