Natural waters, ecotoxic metals

For most tasks in the trace chemistry of natural waters, voltammetric determination requires preconcentration, because in a group of simultaneously determined ecotoxic heavy metals one usually has levels below 0.1 p,g/l. 

Valenta P (1988) Potentialities and applications of voltammetry in the determination of ecotoxic trace metals in natural waters, body fluids and food. GIT Fachz Lab 32 312-317. 

Midpoint indicatois Climate change. Ozone depletion. Photochemical oxidant formation. Particulate matter formation. Ionising radiation. Terrestrial acidification. Human toxicity. Terrestrial ecotoxicity. Freshwater ecotoxicity. Marine ecotoxicity. Metal depletion. Fossil depletion. Water depletion. Freshwater eutrophication. Marine eutrophication. Agricultural land occupation. Urban land occupation and Natural land transformation. Endpoint indicators Human health. Ecosystem diversity and Resource availability. 

Sulfur dioxide and NOj , which also act as a major precursor of acid rain as well as ecotoxic heavy metals and metalloids (Cd, Pb, Hg, Cu, Ni, Zn, As, Se, etc.) have gained considerable significance with regard to the ecotoxic burden on vegetation, soil, natural waters, and as air pollutants. The SO2 emission in the F.R.G. in 1984 had reached the limit of 3.5 million tons a year. ... 

The area where voltammetry offers most particular potentialities and is frequently the most superior method of determination and investigation is the chemistry of ecotoxic metals in all types of natural waters[15]. 

W. Niirnberg, Trace analytical procedures with modern voltammetric determination methods for the investigation and monitoring of ecotoxic heavy metals in natural waters and atmospheric precipitates, Sci.Tot.Environ., 37 9 (1984). 

Resource availability Ecosystem diversity Human health Natural land transformation Urban land occupation Agricultural land occupation Marine eutrophication Freshwater eutrophication Water depletion Fossil depletion Metal depletion Marine ecotoxicity Freshwater ecotoxicity Terrestrial ecotoxicity Human toxicity Terrestrial acidification Ionising radiation Particulate matter formation Photochemical oxidant formation Ozone depletion Climate change L -10%... 

Water is a natural solvent of choice for biocatalysis. However, considering the rather hydrophobic nature of most substrate/product couples used, water seems a rather unsuitable solvent. From the ecotoxicity aspect, water can be easily contaminated by organic and metallic impurities from the reaction, and thus generally requires prior waste treatment before released into the environment... 

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