Screening of antimony in PVC by solid sampling-graphite furnace atomic absorption spectrometry

Origins and carriers of Sb, As, Cd, Cl, Cr, Co, Pb, Hg, and Ni in mixed solid waste - A literature-based evaluation

Antimony, arsenic, cadmium, chlorine, chromium, cobalt, lead, mercury, nickel and their compounds are commonly used in the industrial production of various goods. At the end of the product life cycle, these elements enter the waste system as constituents of the products. Mixed municipal and commercial wastes are landfilled, biologically treated, incinerated, and/or processed in mechanical treatment plants to yield solid recovered fuel (SRF). In all these cases, inorganic contaminants that are present in the input waste material play a significant role. In mechanical waste treatment, materials containing high concentrations of these elements (contaminant carriers) can be selectively removed (e.g. by infrared sorters) to improve the output quality, but prior knowledge about the contaminant carriers is required. This paper reviews several waste-related publications in order to identify carriers of Sb, As, Cd, Cl, Cr, Co, Pb, Hg, and Ni in mixed municipal and commercial waste. Identified contaminant carriers are listed alongside ranges for expected concentrations. Furthermore, the data are combined with information on industrial applications and contaminant concentrations in products in order to discuss the reasons for the presence of the respective elements in the carriers. Generally, besides inerts or metals, identified contaminant carriers often include plastics, composite materials, leather products, textiles, rubber, electronic waste, and batteries. Moreover, it is evaluated how individual contaminant carriers are reflected by chemical waste analyses. While the findings of the paper can be applied to different waste treatment options, the discussion focuses on SRF, which is the main output of mechanical treatment plants.

Progress in direct solid sampling analysis using line source and high-resolution continuum source electrothermal atomic absorption spectrometry

The literature about direct solid sample analysis of the past 10-15 years using electrothermal atomic absorption spectrometry has been reviewed. It was found that in the vast majority of publications aqueous standards were reported as having been used for calibration after careful program optimization. This means the frequently expressed claim that certified reference materials with a matrix composition and analyte content close to that of the sample have to be used for calibration in solid sample analysis is not confirmed in the more recent literature. There are obviously limitations, and there are examples in the literature where even calibration with certified reference materials did not lead to accurate results. In these cases the problem is typically associated with spectral interferences that cannot be corrected properly by the systems available for conventional line source atomic absorption spectrometry, including Zeeman-effect background correction. Using high-resolution continuum source atomic absorption spectrometry, spectral interferences become visible owing to the display of the spectral environment at both sides of the analytical line at high resolution, which makes program optimization straightforward. Any spectrally continuous background absorption is eliminated automatically, and even rapidly changing background absorption does not cause any artifacts, as measurement and correction of background absorption are truly simultaneous. Any kind of fine-structured background can be eliminated by "subtracting" reference spectra using a least-squares algorithm. Aqueous standards are used for calibration in all published applications of high-resolution continuum source atomic absorption spectrometry to direct solid sample analysis.