Electrothermal atomizer laser-excited atomic fluorescence spectrometry for the determination of phosphorus in polymers by direct solid analysis and dissolution

Abstract

Electrothermal atomizer laser-excited atomic fluorescence spectrometry (ETA-LEAFS) with direct solid analysis was used to measure phosphorus in polymers that consisted mainly of poly(ethylene terephthalate). The ETA-LEAFS detection limit for phosphorus was 8 pg, and the linear dynamic range extended over approximately five orders of magnitude. Electrothermal atomic absorption spectrometry (ETAAS) and inductively coupled plasma atomic emission spectrometry (ICP-AES) were used to validate quantitative results obtained. A novel dissolution method that utilized trifluoroacetic acid and toluene was used for validation purposes. Of the three techniques investigated, only ETA-LEAFS, with either direct solid analysis or dissolution, could measure the phosphorus content of all the samples over the range 2–3000 µg g–1; ETAAS and ICP-AES were limited by a relatively poor linear dynamic range and/or poor detection limit. The relative standard deviation for the ETA-LEAFS analyses by dissolution and direct solid analysis was in the range 5–11% and 11–12%, respectively. A general comparison was made between the use of ETA-LEAFS and alternative techniques for the direct solid analysis of polymers.