Determination of trace amounts of boron in steel by high frequency plasma torch spectrometry

Trace amount of boron in steel were determined by means of emission spectrometry using high frequency plasma torch. The sensitivity of this method depended on the kind of solvent used, and methyl alcohol gave the best sensitivity. The determination limit of boron in methanol was 0.002μg/ml. The established method utilized the high sensibility of the plasma torch and the easy distillation of boron in methanol as trimethylborate {B(OCH3)3}. The sample was dissolved by acids and dehydrated by hot H2SO4 and H3PO4. After cooling and addition of methanol (60 ml), the solution was distilled to obtain 40 ml of the distillate. The amount of boron in the distillate was determined by the intensity of the spectral line of B 2497. 73 Å excited by plasma torch. This method was rapid and accurate, particularly in determining trace amounts of boron and the determination range of boron in steel was 0.2 to 150 ppm. This method was also appliciable to stainless steels and other alloys.