A method for the determination of Al2O3, Fe2O3, TiO2, MnO, CaO, and MgO by atomic absorption is described. A 0.5 to 1.0 g sample is put into solution by treatment with HF, followed by fusion of the HF residue with K2S2O7 and solution of the fused material with HCl. Determination of the various elements is then made using an acetylene-nitrous oxide flame and a premix type burner. The method was developed to eliminate the necessity of changing flame parameters because of the refractory and nonrefractory elements involved. National Bureau of Standards 1-A, G-1, W-1, and U. S. Geological Survey standards BRC-1 and PCC-1 were analyzed by the methods described herein and the results obtained agree within 0.1% or less of the listed values. Standard deviations and coefficients of variation were also calculated for all elements determined on each sample and found to be within acceptable limits.
O. Karmie Galle, "Routine Determination of Major Constituents in Geologic Samples by Atomic Absorption," Appl. Spectrosc. 22, 404-408 (1968)