Determination of trace elements in zirconium base alloy by inductively coupled plasma mass spectrometry

The application of inductively coupled plasma mass spectrometry (ICP-MS) to the determination of trace elements in NBS SRM 360a Zircaloy-2 (Zr-2) reference material is described. The constant temperature control system of the instrument was modified to reduce mass calibration drift. Accurate determination of Ti, Cr, Mn, Fe and Cu were achieved using standard calibrations. The standard addition method was used to determine hafnium. Standard addition results were also compared for Ti and Fe, which were not measured with the most abundant isotopes in direct calibration measurements. In both cases, the matrix Zr was not separated. Traces of uranium at the ICP-MS detection limit after dilution, were determined with the stable isotope dilution method. For these determinations, only one tenth of the man-hours are needed compared with conventional methods. The relative standard deviation is within 5%. Effects of an internal standard for ICP-MS with Zr matrix are also discussed. Spectra. 11 ref.--AA