Interlaboratory test on polymers: determination of antioxidants in polyolefins

The relative repeatability of the determinations was between 1.3 and 5.5%, and the relative reproducibility was in-between 12 and 28% for both antioxidants. No matrix or analyte dependence was observed. The combined calculated uncertainty of measurement (uc) in all laboratories was between 36 and 86%. Therefore analysts in different laboratories have to expect large variations in results when comparing the results of antioxidant analysis on the same polymer.