X-Ray spectrographic determination of tantalum in niobium by electron excitation

An X-ray method is proposed for the determination of tantalum in niobium by direct electron excitation. The optimum excitation conditions for greatest sensitivity are given. The limit of detection for a counting time of 400 sec was found to be 20 p.p.m. The relative standard deviation in the 0.4–5% concentration range was ±2%.