Determination of trace amounts of phosphorus in trichloro- and tetrachlorosilane
Abstract
A method is described for the determination of phosphorus below the parts per million level in halosilanes. The sample is hydrolysed in an enclosed vessel and the silicic acid formed is volatilised off. Phosphorus is extracted as molybdophosphate into chloroform-n-butanol mixture. The molybdenum associated with the extracted phosphorus is determined by the thiocyanate method.