Determination of zirconium traces in polymers by ICP-IDMS - a powerful andfast method for routine testing of zirconium residues in polyolefins

Zirconium trace analyses play an important role for polyolefins produced by modern catalytic processes with zirconium metallocenes. A reliable and fas t routine testing method by inductively coupled plasma isotope dilution mas s spectrometry (ICP-IDMS) was therefore developed, which allows the determi nation of zirconium in polymers down to the low ng/g level. With respect to its precision, accuracy, and time-consumption this method is suitable for routine testing of production processes. A spike solution, enriched in the stable isotope Zr-91, was prepared and used for the isotope dilution proced ure, which has the advantage of being an internal "one point" calibration m ethod. The polyolefin samples were dissolved by microwave assisted digestio n with a mixture of concentrated HNO3/HF.