Abstract
X-ray fluorescence methods are described for the accurate quantitative determination of platinum, gold, and iridium in solution. For the platinum determinations, it is shown how corrections for interelement effects can be applied using background intensities to calculate absorption effects. In an alternative method for the platinum determination, zinc was found to be a satisfactory internal standard For the determination of gold and iridium, platinum is used as variable internal standard. Coefficients of variation of less than one % and from one to three % were obtained for platinum and for gold and iridium determinations respectively