Spectrophotometric determination of palladium using iodide and pyronin G

A sensitive and highly selective procedure for the spectrophotometric determination of palladium is described. It is based on the formation of the ternary ion complex Pd-I--pyronin G in a citrate-buffered medium. The colour development is instantaneous and, when stabilized with gelatin, the absorbance remains unchanged for at least 24 h. The colour system obeys Beer's law in the range 1-7 μg of palladium present in a final volume of 25 ml. This method is likely to find widespread use for the determination of palladium in minerals and alloys. © 1983.