Šiame darbe naudojamas Epsilon potenciastato modelis, sujungtas su Epsilon EC-2000-XP(Ver. 1.40.67_NT) programa ir kompiuteriu. Tyrimo metu naudojama trijų elektrodų celė. Darbiniu ir pagalbiniu elektrodais naudojami platinos elektrodas. Palyginamuoju naudojamas Ag/AgCl/KClsot elektrodas. Visos potencialų vertės nurodomos palyginamojo elektrodo atžvilgiu. POT sluoksnis nusodintas potenciostatiniu ir potenciodinaminiu būdu ant platinos elektrodo, keičiant eksperimento sąlygas. Potenciodinaminiai dengimo matavimai atlikti keičiant elektrodo potencialą nuo -0,1V iki 1,0V ir nuo -0,1V iki 1,2V. Dengiant Pt elektrodą buvo atliekama 10 arba 20 ciklų. Potencialo skleidimo greitis – 10, 20, 50 ir 100 mV/s. Potenciostatiniai dengimo matavimai atlikti esant pastoviam potencialui Econst 0,9V, 1,0V ir 1,2V ir dengimo laikui (tdeng) 1, 3 arba 5 minutės. Poli(o-metilanilinu) modifikuoti elektrodai gali būti naudojami askorbo rūgšties analizei tirpaluose, kurių pH 5,5. Askorbo rūgšties koncentracijų intervale nuo 0,1mM iki 1mM gaunama tiesinė oksidacijos ribinių srovių priklausomybė nuo koncentracijos, jei askorbo rūgšties matavimai atliekami potenciostatinėmis sąlygomis. Žemiausia askorbo rūgšties nustatymo riba – 0,1mM. / The Epsilon potentiometer model combined with a PC running Epsilon EC-2000-XP (Ver. 1.40.67_NT) software was used in these theses. During the research, a three-electrode cell was used. A platinum electrode was utilised as the working and auxiliary electrode. An Ag/AgCl/KClsot electrode was used as reference electrode. All values of the potentials refer to this electrode. An POT layer was deposited under potentiostatic or potentiodynamic conditions on platinum electrode by varying parameters of the experiment. Potentiodynamic polymer formation measurements were performed by alternating the electrode potential from 0.1V to 1.0V and from 0.1V to 1.2V. When modifying Pt electrode, 10 or 20 potential cycles were performed. The potential scan rate was 10, 20, 50, and 100 mV/s. Potentiostatic polymer formation measurements were performed under the constant potential Econst 0.9V, 1.0V, and 1.2V, and the time of coating (tcoating) was 1, 3 or 5 minutes. Poly (o-methylaniline) modified electrodes can be used for the analysis of ascorbic acid in solutions with pH values 5,5. Within the concentration interval of ascorbic acid between 0,1mM and 1mM, a linear dependence between oxidation limit currents and concentration was observed when ascorbic acid measurements were carried out potentiostatic conditions. The lowest sensing limit of ascorbic acid was 0,1mM.
| Identifer | oai:union.ndltd.org:LABT_ETD/oai:elaba.lt:LT-eLABa-0001:E.02~2009~D_20090629_130203-74269 |
| Date | 29 June 2009 |
| Creators | Griškalauskaitė, Jolanta |
| Contributors | Malinauskas, Albertas, Jurevičiūtė, Irena, Ščit, Olga, Gefenas, Vladas, Giraitis, Raimondas, Vitėnienė, Irena, Šalkus, Bronislovas, Tumkevičius, Sigitas, Vilnius Pedagogical University |
| Publisher | Lithuanian Academic Libraries Network (LABT), Vilnius Pedagogical University |
| Source Sets | Lithuanian ETD submission system |
| Language | Lithuanian |
| Detected Language | English |
| Type | Master thesis |
| Format | application/pdf |
| Source | http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2009~D_20090629_130203-74269 |
| Rights | Unrestricted |
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