Determination of trace elements in solid plastic materials by laser ablation–inductively coupled plasma mass spectrometry

Abstract

The application of laser ablation inductively coupled plasma mass spectrometry (ICP-MS) to the direct determination of trace elements in solid plastic materials has been studied. A neodymium:yttrium aluminium garnet (Nd:YAG) laser was used to ablate the samples and the particulate matter thus produced was transported to the plasma torch of the ICP-MS system for measurement. The system was applied to the examination of polypropylene, polyester, poly(vinyl chloride), nylon and polyethylene, containing a variety of fillers and other additives. It was found that by using carbon-13 as an internal standard, in order to adjust for variations in ablation and transport of the different sample types, semi-quantitative analysis could be achieved with an accuracy that was within a factor of 2 of the known value for most of the elements investigated. Quantitative measurements made using laser ablation–ICP-MS, and with calibration standards of matrix composition similar to that of the materials being analysed, showed good agreement with known values. The application of the technique to the investigation of the spatial distribution of elements is briefly explored.