Direct determination of phosphorus in two different plastic materials (PETand PP) by solid sampling-graphite furnace atomic absorption spectrometry

P is an element that is difficult to determine accurately by most analytica l techniques when present at low levels. In particular, P is an additive in many plastics and its rapid determination is of economic interest. Solid s ampling graphite furnace atomic absorption spectrometry (SS-GFAAS) may be a n approach that combines high sample throughput with an improvement in sens itivity and it is particularly suitable for dealing with organic matrices w hen speed is more important than high precision. In this work, SS-GFAAS was used for the determination of P in PET (polyethyleneterephthalate) and PP (polypropylene) materials, showing the suitability of the approach for this kind of analysis. In order to enable P determination, a combination of Pd and ascorbic acid was used as a chemical modifier. The results obtained can be considered satisfactory with regard to the sensitivity (LOD 2.5 mu g g( -1)) and precision achieved (7.8% RSD for the PET sample with a P content o f about 45 mu g g(-1) and 6.7% RSD for the PP sample with a P content of ab out 1000 mu g g(-1)), values similar to those obtained for less problematic analytes. Previous analysis of the PET material by means of solid sampling -electrothermal vaporization-ICP-MS (SS-ETV-ICP-MS) enabled us to compare t he performance of both methods. Special attention was paid to the peculiar relationship between signal and sample mass that SS-GFAAS is reported to di splay.