POTENTIOMETRIC DETERMINATION OF Cu 2+ USING ION SELECTIVE ELECTRODES

V diplomskem delu je predstavljena uporaba elektrode pripravljene iz ogljikove paste z dodatki bakrovih soli. Elektrode smo uporabili za potenciometrično določanje koncentracije bakra z direktno potenciometrijo in s potenciometričnimi titracijami. Pri direktni potenciometriji smo meritve izvajali v koncentracijskem območju od 10-5 do 10-1 mol/L. Preverili smo tudi odzivne čase elektrod in ugotavljali v katerem mediju je najbolje hraniti elektrodo pred uporabo in po uporabi. Izmed vseh elektrod se je najbolje odzvala elektroda, ki smo jo pripravili iz 200 mg ogljikove paste in 120 mg Cu2S. Cu2S je bil pripravljen s sonokemijsko metodo. Ta elektroda je bila selektivna, izmerjen potencial pa je premosorazmerno naraščal s koncentracijo bakrovih raztopin. Naklon pri tej elektrodi je znaša -22 ± 0,16 in je bil nekoliko nižji od teoretičnega.The following diploma dissertation describes the use of the carbon paste electrode modified with copper salts. The electrodes were used for the potentiometric determination of copper concentrations by direct potentiometry and potentiometric titrations. When using direct potentiometry, we took measurements in the concentration range from 10-5 to 10-1 mol/L. We also analyzed the response times of the electrodes and determined which medium is the most appropriate to store the electrode in before and after its use. Out of all the electrodes tested, the one prepared with 200 mg of carbon paste and 120 mg Cu2S proved to be the most responsive. Cu2S was prepared using the sonochemical method. This electrode was selective and its measured potential increased proportionally to the concentration of copper solutions. The slope of the electrode was -22 ± 0.16 and was slightly lower than the theoretical one