Microwave-assisted aqua regia digestion for determining platinum, palladium, rhodium and lead in catalyst materials

► HCl + HNO3 and HCl + HNO3 + HF digestion procedures were developed for catalyst materials. ► Good recoveries for Pd, Pt, Rh and Pb were obtained at 160 °C. ► Temperature-controlled extraction can be used to separate Pd, Pt, Rh and Pb from the major elements in catalyst materials.