Spectrochemical Analysis of Refined Rhodium
Techniques for spectrographic determination of minor constituents in refined rhodium are described. These involve preparation of spectrographic standards in both sponge and black forms and conversion of refinery samples to the same forms for analysis. Principal contaminants are: iridium, :palladium, iron, nickel, and silica, but platinum, ruthenium, gold, silver, copper, tin, lead, zinc, and cobalt may also be present. The ranges of concentration covered are those necessary for analysis of refinery production samples. Samples are mixed with graphite powder and pressed into pellets. Excitation is provided by either high-voltage spark or direct-current arc discharges as required for adequate sensitivity.