Solid sampling-graphite furnace atomic absorption spectrometry for the direct determination of trace amounts of silicon in polyamide. Comparison of the performance of platinum and palladium as chemical modifiers

Abstract

In this paper, the use of solid sampling-graphite furnace atomic absorption spectrometry for the direct determination of silicon in a polyamide sample at the 10 μg g −1 level has been investigated. The performance of Pt and Pd as chemical modifiers for the reproducible atomization of this element has been compared, both for aqueous solutions and for solid samples. According to the results obtained, it can be concluded that Pt is an interesting alternative to Pd, since it is capable of providing a similar performance with the use of lower modifier amounts (1 μg of Pt vs. 20 μg of Pd for direct analysis of the sample). The method proposed shows important benefits for the determination of such a complicated element: the use of aqueous standards for calibration, low sample consumption (a few milligrams), high sample throughput (20 min per sample), low limit of detection (0.1 μg g −1) and reduced risk of analyte losses and, especially, of contamination, while precision is fit for the purpose (approx. 6% R.S.D.).