Ispitivan je nastanak kompleksa L-histidina i bakra u omjeru 1 : 1 u području pH od pH = 4 do pH = 10. Istraživanja su provedena u elektrokemijskoj ćeliji, gdje je kao radna elektroda upotrijebljena ...elektroda od staklastog ugljika, kao referentna Ag/AgCl elektroda te kao protuelektroda platinska žica. Utvrđeno je da kompleks bakra i histidina nastaje u području od pH = 6 do pH = 10 te da se oksidacijski potencijal metalnog iona u kompleksu negativira s povećanjem pH. Struja oksidacijskog strujnog vrha raste do pH = 8 te nakon toga opada, dok se potencijal oksidacijskog strujnog vrha linearno smanjuje s povećanjem vrijednosti pH.
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The main goal of this study was to investigate complexation of L-carnosine and its constituent amino acids β-alanine and L-histidine with copper (II) in a buffer at pH = 10. For this study the ...following methods were used: potentiometry, cyclic and differential pulse voltammetry and UV/VIS spectroscopy. The results have shown that L-histidine and L-carnosine formed a complex with copper in a 1:1 ratio, while no complexation with β-alanine was observed.
In this work oxido-reduction properties of L-histidine were studied by cyclic and differential pulse voltammetry in a pH range from pH 4-10. The results have shown that L-histidine is not ...electroactive in a pH range from pH 4 to pH 9, while oxidation peak of L-histidine's imidazole ring at pH 10 was detected with differential pulse voltammetry. It has been found that the oxidation peak current of L-histidine increased with the increase of its concentration in a solution. Adsorption of oxidation product of L-histidine on a glassy carbon electrode surface was also detected. Voltammetric techniques (cyclic and differential pulse voltammetry) and UV/VIS spectroscopy were used to study formation of L-histidine complexes with transition metals. It has been found that L-histidine formed octahedral complex with metal ion (Co.sup.2+ and Ni.sup.2+) in a 1 : 1 ratio. Keywords: cyclic and differential pulse voltammetry, L-histidine, metal complexes.
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