Spectrographic determination of traces of B, Be, Cd, Si and Co in U3O8 by the d.c. arc cathode-region method

Abstract

The cathode region of the d.c. arc emission of U3O8 has been photographed (0.6 mm below the cathode) from 2,200 to 3,400 A, using Scribner-Mullin carrier distillation electrodes. Along with the elemental spectra of trace impurities in U3O8, a well resolved Mulliken band (1Σ u + → 1Σ g + ) of the C2 molecule has been observed in the 2,300 A region and its intensity has been found to follow the excitation conditions of the arc. Using some of the well resolved rotational lines in the Mulliken band of C2 molecule as internal standard lines, the trace impurities with analytical lines in 2,200 –2,500 A region (B, Be, Cd, Si and Co) have been satisfactorily determined. This method offers several advantages compared to the well established “carrier distillation” and also the “cathode region” method described by Avni as it has a “built-in” internal standard.