Halogen analysis of sulphide minerals at the ultratrace level – first applications of the Dresden Super-SIMS

The integration of an ion source having very high spatial resolution with a tandem accelerator is a long-standing concept for improving analytical selectivity and sensitivity by orders of magnitude [1]. Translating this design concept into reality has its challenges [e.g. 2,3], meaning this approach has seldom been employed for mineralogical and geochemical research [e.g. 4].
Supporting a strong focus on natural, metallic and mineral resources, the Helmholtz Institute Freiberg for Resource Technology installed a so-called Super-SIMS at the Ion Beam Center at HZDR in Dresden-Rossendorf; this highly novel tool is devoted to the characterization of minerals and ores. The secondary ion beam from a CAMECA IMS 7f-auto is injected into the 6MV Dresden Accelerator Mass Spectrometry [5] facility, which effectively eliminates all molecular species from the ion beam.
We will present the current status of this initiative and will report our first results from halogen determinations (F, Cl, Br, I) in both sphalerite and galena. These data demonstrate a systematic and significant change in the counting rates of all halogens in mineralogically distinct areas of both minerals. Furthermore, we will describe our concepts for the quantification of these data at ultratrace levels.

[1] Matteson (2008) Mass Spec Rev 27, 470-484. [2] Ender et al. (1997) NIMB 123, 575-578. [3] Fahey et al. (2016) Anal Chem 88, 7145-7153. [4] Sie et al. (2000) NIMB 172, 228-234. [5] Rugel et al. (2016) NIMB 370, 94-100.