Improving the detection limit of silicon, magnesium and aluminum in neutron activation analysis of polymers using a TRIGA^® reactor

Abstract

The measurement of impurities, specifically; the combination of magnesium, silicon and aluminum, in polymers and in mixed additives is a common problem for industrial application of neutron activation analysis (NAA). Typically this problem can be addressed using XRF and ICP. However, in some cases, the available sample size, desired detection limit and the desired accuracy prohibit the use of XRF or ICP. Therefore under these requirements, as in the measurement of talc in milligram size polymer fibers, using NAA has become a niche for nuclear analytical applications. Other important advantages, apart from high precision and lower detection limit, are the non-destructive nature of the analysis and the minimal sample preparation necessary to carry out the measurement. Therefore, polymers such as polyethylene, polystyrene or poly-carbonate can be analyzed for these metals as organic solutions, beads, films, pellets or powders. This paper highlights some of the recent improvements made to the Dow NAA measurement facility to accomplish this task.