Manganese volatile elements

Chemical ingenuity in using the properties of the elements and their compounds has allowed analyses to be carried out by processes analogous to the generation of hydrides. Osmium tetroxide is very volatile and can be formed easily by oxidation of osmium compounds. Some metals form volatile acetylacetonates (acac), such as iron, zinc, cobalt, chromium, and manganese (Figure 15.4). Iodides can be oxidized easily to iodine (another volatile element in itself), and carbonates or bicarbonates can be examined as COj after reaction with acid. 

The bulk compositions of chondrites closely match the compositions of the solar photosphere, with the exception of a few highly volatile elements (hydrogen, carbon, nitrogen, helium) and lithium (see Chapter 1.03). The chondrite groups also show different levels of depletions in moderately volatile elements (e.g., manganese, sodium, potassium, gallium, antimony, selenium. 

The concentrations of four typical moderately volatile elements—manganese, sodium, selenium, and zinc—in the various classes of chondritic meteorites are shown in Figure 12, where elements are normalized to magnesium and CI-chondrites. Again there is excellent agreement between solar abundances and Cl-meteorites. A characteristic feature of the chemistry of carbonaceous chondrites is the simultaneous depletion of sodium and manganese in all types of carbonaceous chondrites, except Cl. Ordinary and enstatite chondrites are not or only slightly... 

In Figure 13 the Earth s mantle seems to extend the trend of the moderately volatile elements to lower abundances, at least for sodium, manganese, and zinc (zinc behaves as a lithophile element in the Earth s mantle (see Dreibus and Palme, 1996)). The elements lithium, potassium, and rubidium which are not plotted here, show similar trends. The carbonaceous chondrite trend of iron is not extended to the Earth, as most of the iron of the Earth is in the core. The magnesium abundance of the Earth shows a slightly different trend. If the core had 5% silicon (previous section) and if that would be added to the bulk Earth silicon, then the bulk Mg/Si ratio of the Earth would be the same as that of carbonaceous chondrites (Eigure 10) and the silicon abundance of the Earth s mantle in Figure 13 would coincide with the magnesium abundance. 

The depletion of moderately volatile elements such as manganese, sodium, rubidium in the... 

In summary, it appears from Figure 17 that the bulk composition of the Earth is related to the carbonaceous chondrites, suggesting the same event of manganese depletion for carbonaceous chondrites and the Earth. This supports the hypothesis that the depletion of volatile elements in the various solar system materials is a nebular event at the beginning of formation of the solar system as suggested by Palme et al. (1988), Humayun and Cassen (2000), and Nyquist et al. (2001). 

In the case of cobalt, 1.6 ng cobalt are added to the diesel sample, as the element shows a lower sensitivity in comparison to manganese and iron. Limit of detection and quantitation of cobalt are affected by the low sensitivity of THFA for low volatile elements (Table 4). 

Hopke, et al. (4) and Gaarenstroom, Perone, and Moyers (7) used the common factor analysis approach in their analyses of the Boston and Tucson area aerosol composition, respectively. In the Boston data, for 90 samples at a variety of sites, six common factors were identified that were interpreted as soil, sea salt, oil-fired power plants, motor vehicles, refuse incineration and an unknown manganese-selenium source. The six factors accounted for about 78 of the system variance. There was also a high unique factor for bromine that was interpreted to be fresh automobile exhaust. Large unique factors for antimony and selenium were found. These factors may possibly represent emission of volatile species whose concentrations do not oovary with other elements emitted by the same source. 

---