The Application of the Potentiometric Stripping Analysis to Determine Traces of M(II) Metals (Cu, Zn, Pb and Cd) in Bioinorganic and Similar Materials

The development and application of new technologies in all spheres of life and work carries with it the ever-increasing pollution of the environment through harmful and toxic substances. Pesticides and heavy metals are among some of the more prominent pollutants of the environment. Heavy metals significantly contribute to human environment pollution due to the impossibility of their biodegradation, and because some of them have cumulative toxic properties. Sources of contamination by means of metals are numerous, the most important ones being combustion products in the chemical industry and metallurgy, industrial waste waters and landfills, agrochemicals, and exhaust gasses of motor vehicles. People are, therefore, exposed to toxic metals that act both directly through the contaminated air and drinking water, and indirectly through the soil, underground waters and poisoned plants and animals found in food, the pharmaceutical and cosmetic industry. Copper and zinc are essential bioelements which, in addition to their biological role and their importance for the development of the human body, also have a toxic effect when found in amounts higher than normal in the human body. Lead and cadmium are highly toxic metals, even when found only in traces (Goyer, 1997; Goyer & Klaassen, 1995). Copper is one of the essential biometals necessary for the growth, development and normal functioning of the human body, for the synthesis of hemoglobin, melanin, and the mineralization and development of bones. The lack of copper can lead to serious illnesses. Nevertheless, its presence in the human body in values greater than 10-6 mol/dm3 inhibits certain enzymes, which hinders the bonding of other essential microelements, or even leads to bonding with certain cofactors. The increased content of copper in the human body leads to coronary and vascular disease, arteriosclerosis, hypertension and various forms of damage to the central nervous system (Uauy, et al., 1998; Hart, et al. 1928; Chapman, 2008). Zinc is an essential oligoelement which is found in significant amounts in the human body (0.02 – 0.03 g/kg of body weight). It is necessary for the synthesis of proteins and nucleic acids, DNA replication, the human reproductive ability, and maintaining high level healthy immune function. A shortage of zinc in the human body can lead to the harmful effect of