The U.S. Bureau of Mines has developed a thin-film x-ray fluorescence technique to rapidly determine cu, ni, CO, fe, and cr in superalloy leach liquors. Total analysis time per sample was less than 15 min, as opposed to several hours for traditional wet chemical methods. Precision and accuracy were checked by replicate analyses of solutions similar in composition to leach liquors, whose analyte concentrations were well known. Coefficients of variation for all elements were found to be less than 2 pct. With the exception of the results for fe, all relative errors of estimation were also found to be less than 2 pct. Bulk liquids are not introduced into the spectrometer; thus, the potential for damage to the instrument by leakage of corrosive liquids is eliminated.