OXYGEN Irish

The level of soluble thallium present in the sea (e.g. Pacific Ocean, Atlantic Ocean, Irish Sea, Australian Coast) is between 9 and 16 ng/L (Matthews and Riley, 1970). This is remarkably lower than in fresh waters. In natural sea water (pH 8.1), the oxygen content is sufficient to oxidize Tl(l) to Tl(lll). because formation of chloro-complexes stabilizes the trivalent state. In the Pacific Ocean, 80% of the thallium was found to occur as Tl(lll), and only 20% as the sum of Tl(l) and alkylthallium compounds (Batley and Florence, 1975). As Tl(lll) is easily adsorbed and coprecipitated, it continuously moves down to the sediments. 

The thiourea derivative, l-[3,5-di(trifluoromethyl)phenyl]-2-thiourea (Tl) was purchased from Fluorochem Ltd (Derbyshire, UK). A 1000 ppm spectrosol solution of Au as an AuCV solution was obtained from BDH Chemicals Ltd. (Poole, England). All CO2 gas cylinders were fitted with dip tubes and bought from Irish Oxygen (Cork, Ireland). All extracted samples after SFE were collected in either methyl iso-butyl ketone (MIBK), DMSO (bodi purchased from BDH) or methanol (Merck, Germany) as indicated. 

Dutta I, Carpenter MK, Balogh MP, Ziegelbauer JM, Moylan TE, Atwan MH, Irish NP (2010) Electrochemical and stmctnral study of a chemically dealloyed PtCu oxygen reduction catalyst. J Phys Chem C 114(39) 16309-16320... 

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