Direct multi-element analysis of a fluorocarbonpolymervia solid sampling-electrothermal vaporization-inductively coupled plasma mass spectrometry

Abstract

This paper reports on the performance of solid sampling-electrothermal vaporization-inductively coupled plasma mass spectrometry for the direct multi-element analysis of two different perfluorosulfonic acid/TFE copolymer samples, which were selected in order to test the potential of this technique for routine control of fluorocarbon polymers. Careful selection of the most suitable isotopes permits the reliable monitoring of the analytes of interest: Cr, Cu, Fe, K, Mn, Pb and Zn. The use of Pd as chemical modifier allows stabilization of all of these analytes during the pyrolysis step (at 800 °C), enabling adequate matrix removal, while the use of a high vaporization temperature (2700 °C) is required for the efficient simultaneous vaporization of these elements. Moreover, the ¹⁰⁵Pd⁺ signal can be used as internal standard, correcting for possible sensitivity drifts. Under these conditions, straightforward calibration with aqueous standard solutions was feasible for all of the elements investigated. The method thus developed exhibits interesting features, such as a low detection limit (ng g⁻¹ range) for most elements, a high sample throughput (15 min per determination), a low sample consumption (a few milligrams only), precision values usually in the 7–12% RSD range and the absence of any sample pretreatment, with the subsequent lower risk of analyte losses or contamination. Therefore, it seems to offer a promising alternative for the laborious procedures currently in use for analysis of these complex samples.