Humic substances chromium

Wittbrodt, P.R. and C.D. Palmer. 1996. Effect of temperature, ionic strength, background electrolytes, and Fe(IH) on the reduction of hexavalent chromium by soil humic substances. Environ. Sci. Technol. 30, 2470-2477. 

Speciation studies have been focused on relatively few elements, mainly aluminum, antimony, arsenic, chromium, lead, mercury, selenium, and tin. The primary species of these elements studied with ICP-MS detection are presented in Table 3 and they include different oxidation states, alkylated metal and/or metalloid compounds, selenoaminoacids, and selenopeptides. In addition, applications in studies of the pharmacokinetics of metal-based drugs (Pt, V, Au), metalloporphyrins (Ni, V, Fe, etc.), heavy metals in phytochelatins (Cd, Cu, Zn, Hg, etc.) and in humic substances should be mentioned. 

Yamazaki, H., Hohda, S., and Nishikawa, Y. (1980). Chemical forms of chromium in natural water—interaction of chromium(III) and humic substances in natural water. J. Oceanogr. Soc. Japan 35, 233-240. 

Van De Velde K, Ferrari C, Barbante C, Mret I, Bellomi X Hong S, and Boutron C (1999) A 200 year record of atmospheric cobalt, chromium, molybdenum, and antimony in high altitude alpine firn and ice. Environ SdTechnol 33 3495-3501. Var F, Narita Y and Tanaka S (2000) The concentration, trend and seasonal variation of metals in the atmosphere in 16 Japanese cities shown by the results of National Air Surveillance Network (NASN )from 1974 to 1996. Atmos Environ 34 2755-2770. VoELKER B, Morel F and Sulzberger B (1997) Iron redox cycling in surface waters ffects of humic substances and light. Environ Sd Tedmol 31 1004-1011. 

In Figure 3 the metal concentrations in the various extracts are related to the percentages of the extracted carrier material in the grain size fractionated samples (humic substances, hydrous iron oxides, manganese oxides, carbonate minerals, organic and inorganic residues). For lead, copper, and chromium, the moderately reducible fraction dominates... 

In species-unspecific isotope dilution techniques, an isotopically enriched standard solution is added post-column, and the data evaluation is performed as described in Section 7.3.4 for CE coupling. Species-unspecific isotope dilution for HPLC coupling has been described for the determination of Cd, Cu and Zn in metallothioneins extracted from eel liver, while Fe, Cu and Zn were determined in proteins separated from human serum. This technique has also been applied to iodine determination in humic substances,as well as selenium speciation in human serum. Species-specific isotope dilution using HPLC-ICP-MS has been described for selenium analysis, the analysis of organotin species in sediments, methylmercury in fish tissue, trimethyllead in water, and chromium speciation. Overviews to this topic have been published, e.g. by Heumann and Hill. ... 

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