Spectrographic determination of ultramicro amounts of boron in high-purity silicon tetrachloride and trichlorosilane

A new sensitive method is proposed for the determination of boron in highpurity silicon tetra chloride and trichlorosilane. The method consists of complexing boron with triphenylchloromethane, removal of excess silicon tetrachloride, hydrolysis of the complex, and improved spectrographic excitation of liberated boric acid.The best sensitivity attainable is 0.03μg B, which corresponds to 0.06 p.p.b. B for a 500-g sample.