ABSTRACT
Analytical chemists have realized that the determination of the total amount (concentration) of specifi c chemical elements cannot provide the required information about the mobility, bioavailability and the impact of the specifi c chemical element on the ecological systems or biological organisms. Only knowledge about the exact concentration of the specifi c compounds can lead to an understanding of chemical and biochemical behavior involving these compounds. These will provide correct information about dose-linked “toxicity” or “essentiality” of different “species” of the same element in biological systems. The growing awareness of the strong dependence of the toxicity of elements on their specifi c chemical forms has led to an increasing interest in the qualitative and quantitative methods of determination of specifi c species.
