Ultratrace potassium determination in plutonium oxide

A new method improving the detection limit for potassium in plutonium oxide samples in a high acid matrix was developed. Ultratrace detection limits (sub parts per million) for potassium in plutonium oxide digestate were achieved by optimizing several instrument parameters. Using the Horiba Jobin–Yvon Ultima 2 ICP-AES spectrometer different settings and conditions were examined to improve the detection limit for potassium. The optimized parameters of 0.875 L min−1 sheath gas flow, 20/80 µm entrance/exit slit, 8 s MAX mode signal integration, and blank subtraction were able to lower the potassium reporting limit to 10 ng mL−1.