Table IV. Thorium Contents of Typical Commercial (NH& Ce(NO& “Reagent,” Primary Standard,” and “Standard of Reference” Grade Samples. Sample Th in Ce, 0.96 Reagent Grade #l Reagent Grade #2 0.69 Reagent Grade #3 0.52 Reagent Grade #4 0.30 0.28 Reagent Grade #5 0.38 Primary Standard Grade #1 Primary Standard Grade #2 0.34 Primary Standard Grade #3 0.24 Primary Standard Grade #4 0.03 Primary Standard Grade #5 0.01 Primary Standard Grade #6
