Simultaneous Determination of Calcium, Lithium, and Potassium in High-Purity Thorium Dioxide

Abstract

In the determination of calcium, lithium, and potassium in a refractory matrix such as thorium dioxide, the task can be accomplished using a carrier distillation technique with gallium oxide or silver chloride as the carrier. Complications arise, however, if low concentrations require the use of the most sensitive analytical lines of each: e.g., Ca 3933.67, Li 6707.84, and K 7664.91. The resultant need for broad wavelength coverage at highest sensitivity would require two or three separate exposure conditions with three different photographic plate emulsions. Ideally, Ca 3933.67 A would require an SA-1 emulsion; Li 6707.84 A would require a II-F, usually with a filter to remove scattered light; and K 7664.91 A would require a 1-N with a filter (Corning Glass 3484) mounted in front of the slit to remove interfering second-order cyanogen bands.