Question

5 applications of polarography

Answer 1

II. Investigation of structure and the effect of substituents on the reactivity of organic compounds 342

III. Detection of hydrogen bonds and chelate rings 347

IV. Study of tautomeric changes 348

V. Study of the stereoisomerism of organic compounds 351

VI. Study of the kinetics of chemical reactions 353

Answer 2

The half-wave reduction potentials of a range of nitroheterocyclic compounds were measured polarographically and compared with their radiosensitizing abilities in a simple radiation biochemical assay for damage to 5'-GMP. The chemical enhancement ratio for sensitization of inorganic phosphate release from irradiated 5'-GMP, increased with sensitizer electron affinity, but in a non-linear manner. An onset of sensitization was observed for nitroheterocyclics with half-wave potentials less negative then -0.05V vs. standard calomel electrode and maximum sensitization, approaching the oxygen effect, was obtained at a sensitizer half-wave potential of -0.25 V vs. standard calomel electrode. Nitroheterocyclic sensitizers with half-wave potentials in this range may be potential clinical radiotherapeutic agents.