Applications Of Polarography:
Most metal ions are reducible at DME, and multicomponent mixtures can frequent be analysed through selecting an appropriate supporting electrolyte so in which the half-wave potentials of two ions are differed through about -0.2 V vs SCE or by using complexing agents by taking the advantage of complexing ability of the metal ions.
Based on this, polarography is used predominantly for trace metal analysis of alloys, ultra-pure metals, minerals/metallurgy, environmental analysis (air, water, and soil and sea water contaminants), foodstuffs, beverages and body-fluids, toxicology and clinical analysis. Reducible anions such as BrO-, IO3-, and Cr2O2- and NO2- could also be determined using well buffered solutions.
Table 9.1: Different samples and Element or Compound determined
Parts or Compound determined Type of sample
Cu, Pb, Sn, Zn Foodstuffs
Ga, Zn, Cd, Ni high purity aluminium
Cu, Pb, Ni, Co Steels
Sn, Pb Beer and soft drinks
Transition metals High-purity salts
Free sulphur Petroleum fractions
Antioxidants Fuels
Riboflavin Milk, pharmaceuticals
Vitamin C Fruit and vegetables
Oxygen Sea water, gases
It is also meaningfu in the analysis of biological systems to determine vitamins, hormones, alkaloids, terpenoid substances and natural colouring substance, analysis of drugs and pharmaceutical preparations, determination of pesticide or herbicide residues in foods, in the structure determination of several organic compounds etc.