20.500.12556/DKUM-77074 Validacija metode za določanje Zn(II), Cd(II) in Pb(II) z uporabo internega standarda diplomsko delo univerzitetnega študijskega programa I. stopnje Method validation for Zn(II), Cd(II) and Pb(II) determination using internal standard. Diplomsko delo predstavlja delno validacijo metode za določanje Zn(II), Cd(II) in Pb(II) v sledovih z uporabo modifikatorja in internega standarda Bi(III). Za izvajanje elektrokemijskih meritev smo uporabili modificirano delovno elektrodo iz steklastega ogljika z Bi-prevleko (tvorjena in-situ), Ag/AgCl(nasičen KCl) referenčno elektrodo ter platinasto žičko kot pomožno elektrodo. Elektrokemijske meritve smo izvedli s square-wave anodno stripping voltametrijo, kjer smo z namenom izboljšanja natančnosti in točnosti metode ter doseganja širšega linearnega koncentracijskega območja uporabili signal modifikatorja kot signal internega standarda. V okviru delne validacije metode smo določili meje zaznavnosti in meje določljivosti na podlagi razmerij signal/šum, ki sta znašali 3,8 μg/L in 5,7 μg/L za Zn(II), 0,8 μg/L in 2,7 μg/L za Cd(II) ter 0,4 μg/L in 1,2 μg/L za Pb(II). Linearna koncentracijska območja metode smo določili brez in z upoštevanjem signala za interni standard. Ugotovili smo, da metoda z upoštevanjem signala internega standarda v primerjavi z metodo brez upoštevanja le-tega razširi koncentracijsko linearno območje za vse analizirane ione. Točnost smo preverjali z določevanjem koncentracije analitov z uporabo metode večkratnega standardnega dodatka, kjer smo ugotovili, da je metoda z uporabo internega standarda Bi(III) pokazala slabšo točnost za Zn(II) in Cd(II), kot v primerjavi z metodo brez upoštevanja le-tega. Za Pb(II) ion smo opazili obraten trend vpliva internega standarda, saj se je točnost metode z njegovo uporabo izboljšala. Pri preverjanju natančnosti metode smo ugotovili, da je uporaba Bi(III) vplivala na izboljšanje natančnosti za vse tri analite. The thesis presents a partial method validation for trace Zn(II), Cd(II), and Pb(II) determination using Bi(III) as the electrode modifier and as the internal standard. For electrochemical measurements, a modified Bi-film glassy carbon working electrode (formed in-situ), an Ag/AgCl(saturated KCl) reference electrode, and a platinum wire counter electrode were employed. Electrochemical measurements were performed by square-wave anodic stripping voltammetry, using a signal for the modifier as the signal of the internal standard to improve the accuracy and precision of the method and to achieve a wider linear concentration range. Within the partial method validation, the limits of detection and the limits of quantification were determined based on the signal-to-noise ratio to be 3.8 μg/L and 5.7 μg/L for Zn(II), 0.8 μg/L and 2.7 μg/L for Cd(II) and 0.4 μg/L and 1.2 μg/L for Pb(II). The linear concentration ranges of the method were determined without and with consideration of the signal of the internal standard. We found that the method using the signal of the internal standard widens the linear concentration range for all analytes compared with the method without considering the internal standard. Accuracy was checked by concentration determination of the analytes using the multiple standard addition method. We found that the method using the internal standard Bi(III) showed lower accuracy for Zn(II) and Cd(II) compared with the method without consideration of the internal standard. For the Pb(II) ion, we observed an opposite trend of the internal standard influence, where the accuracy of the method was improved by using the internal standard. Moreover, the precision of the method using the Bi(III) signal as the internal standard was improved for all three analytes. anodna stripping voltametrija elektroda iz steklastega ogljika analiza težkih kovin interni standard anodic stripping voltammetry glassy carbon electrode heavy metal analysis internal standard true true false [A. Novak] Slovenski jezik Angleški jezik Diplomsko delo/naloga 2020-08-14 14:37:38 2020-10-09 07:00:45 2022-08-09 14:19:44 2020-10-16 03:15:47 2020 0 Maribor 0 Maribor IX, 28 str. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 543.552(043.2) 32448003 URN:SI:UM:DK:D5SB0MIP UN_Novak_Anze_2020.pdf UN_Novak_Anze_2020.pdf 1 A32C551AEC8A59D70F19FE77E7067997 511c332f676b399edc9f1e6efbfe5d0454cf915abc234d6611971b4507a6ab94 e4391755-7c11-11eb-bb7a-00155d0001ca 20.500.12556/dkum/ddfb9eef-ca8b-4d0f-ae22-f691177b2402 https://dk.um.si/Dokument.php?lang=slv&id=146392 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0