Abstract

P is an element that is difficult to determine accurately by most analytical techniques when present at low levels. In particular, P is an additive in many plastics and its rapid determination is of economic interest. Solid sampling graphite furnace atomic absorption spectrometry (SS-GFAAS) may be an approach that combines high sample throughput with an improvement in sensitivity and it is particularly suitable for dealing with organic matrices when 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 µg g⁻¹) and precision achieved (7.8% RSD for the PET sample with a P content of about 45 µg g⁻¹ and 6.7% RSD for the PP sample with a P content of about 1000 µg 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 the performance of both methods. Special attention was paid to the peculiar relationship between signal and sample mass that SS-GFAAS is reported to display.