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This work investigates the possibility of obtaining Br isotopic information by generating a gaseous diatomic molecule in a graphite furnace and monitoring its absorption spectrum using a high-resolution continuum source device (HR CS GFMAS). Different metals (Al, Ba, and Ca) were investigated to produce this diatomic molecule and the most promising results, both in terms of isotopic shift and sensitivity, were obtained with Ca, thus leaving CaBr as the target species. The results demonstrate that, unlike what occurs when monitoring atomic spectra, which are characterized by very small isotopic shifts that can hardly be detected, using HR CS GFMAS it is feasible to observe several molecular transitions corresponding to Ca79Br and Ca81Br that are spectrally resolved (i.e. they act like two different molecules absorbing at different wavelengths), and can be simultaneously quantified. The method developed relies on the addition of both Pd and Ca (as a chemical modifier and molecule forming agent, respectively), the selection of peak height values and the use of IBC-m (iterative baseline correction for the monitoring of molecules) for setting the baseline. This method enables accurate Br isotopic analysis in 10 mg L−1 solutions with precision values around 2.5% RSD, without requiring any method for mass bias correction. Moreover, it is also demonstrated how the use of isotope dilution for calibration can help in circumventing severe chemical interferences (e.g., deriving from the presence of high amounts of Cl) when aiming at the direct determination of Br in solid samples by HR CS GFMAS. The accuracy of the method was evaluated via analysis of two different reference materials, poly(vinyl chloride) and tomato leaves. [ABSTRACT FROM AUTHOR]

This work examines the new possibilities introduced with the arrival of commercially available high-resolution continuum source atomic absorption spectrometers for the determination of metalloids (B, Si, Ge, As, Se, Sb and Te) and non-metals (P, S, F, Cl, Br, I and N-based species), such as the improved potential to detect and correct for spectral overlaps and the strategies available to correct for matrix effects. In particular, and considering the increasing number of papers reporting on the use of molecular absorption spectrometry using graphite furnaces and flames as vaporizers, the work discusses in detail the advantages and limitations derived from the monitoring of molecular spectra from a practical point of view, in an attempt to guide future users of the technique. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: This paper reports on the use of solid sampling-graphite furnace atomic absorption spectrometry for the direct analysis of synthetic amorphous silica. In particular, determination of hazardous elements such As, Cd, Cr, Cu, Pb and Sb is investigated, as required by regulations of the food industry. The conclusion of the work is that, after proper optimization of the working conditions, paying particular attention to the atomization temperature and the use of proper modifiers (graphite powder, HNO3 or Pd), it is possible to develop suitable procedures that rely on the use of aqueous standard solutions to construct the calibration curves for all the elements investigated. The proposed method shows important benefits for the cost-effective analysis of such difficult samples in routine labs, permitting fast screening of those elements that are very rarely present in this type of sample, but also accurate quantification of those often found, while offering low limits of detection (always below 0.1mgg−1) that comply well with legal requirements, and precision levels that are fit for the purpose (approx. 6–9% R.S.D.). [Copyright &y& Elsevier]