20.500.12556/RUL-180361 Vplivi redčenja mineralne in morske vode na profile vrhov pri kationski kromatografiji Influence of mineral and seawater dilution on peak profiles in cation chromatography V magistrskem delu sem raziskala vplive redčenja kompleksnih vzorcev na profile kro-matografskih vrhov. Za raziskavo sem uporabila vzorce mineralne vode Donat Mg in morske vode, ki se razlikujeta po koncentracijskem razponu in razmerjih kationov. Za vsak vzorec sem pripravila po 6 različno redčenih raztopin in jih analizirala s kationsko kromatografijo. Pridobljene kromatograme sem ustrezno obdelala, integrirala in iz njih pridobila rezultate za ploščine, višine in retencijske čase vrhov. Te podatke sem računsko in vizualno (s pomočjo izrisa grafov z orodjem MS Excel) analizirala. Potrdila sem, da ima redčenje pomemben vpliv na ploščino, višino in retencijske čase kromatografskih vrhov, kar je neposredno povezano z ionsko močjo vzorca ter interakcijami med ioni v koloni. Pri obeh kompleksnih vzorcih se z redčenjem signali sistematično zmanjšujejo, medtem ko se retencijski časi podaljšujejo. Izjema je natrijev ion, pri katerem se retencij-ski čas z redčenjem krajša, kar je moč pripisati preobremenitvi kolone ter vplivu visoke koncentracije dvovalentnih ionov. Idealni kromatografski vrh ima Gaussovo obliko, je simetričen, dobro ločen od sosednjih vrhov in ima stabilen retencijski čas. V tej nalogi lahko opazimo, da je prišlo do pojava čelnosti, ki je značilen za preobremenitev kolone, ter repatosti kot posledice počasne desorpcije analita z izmenjevalnih mest. Posledično na kromatogramih opazimo prekrivanje posameznih kromatografskim vrhov, kar oteži kvantitativno določitev, lahko pa celo kvalitativno (v primeru stroncijevega iona). Iz primerjave različnih integracijskih metod, ki jih ponuja programsko orodje PeakNet, sem prišla do ugotovitve, da je v mojem primeru najboljša integracijska metoda tangentnega posnemanja. Za oba vzorca sem na podlagi vizualne presoje in statistične analize podat-kov ploščin ter višin vrhov (izračun RSD za posamezne vrhove ionov) določila najpri-mernejši raztopini za določanje sestave kompleksnih vzorcev. Za Donat Mg je to razto-pina A3 s faktorjem redčenja 60,73, za morsko vodo pa raztopina z oznako A5 s faktor-jem redčenja 23,80. S pridobljenimi rezultati v tem magistrskem delu se odpirajo možnosti za razširitev razi-skav. Smiselno bi bilo vključiti še druge kompleksne vzorce z različno ionsko sestavo in tako preveriti, če ti potrjujejo ugotovitve iz tega dela. In my work, I examined the effects of dilution of complex samples on chromatographic peak profiles. For the study, I used samples of Donat Mg mineral water and seawater, which differ in concentration range and cation ratios. For each sample, I prepared six differently diluted solutions and analyzed them by cation chromatography. The resulting chromatograms were appropriately processed, integrated, and used to derive results for peak areas, heights, and retention times. These data were then analyzed both computati-onally and visually (by plotting graphs using MS Excel). The results confirmed that dilu-tion has a significant effect on the peak areas, heights, and retention times of chromato-graphic peaks, which is directly related to the ionic strength of the sample and to in-teractions between ions within the chromatographic column. For both complex samples, increasing dilution led to a systematic decrease in signal intensity, while the retention times of most ions increased. An exception is the sodium ion, for which the retention time shortens upon dilution, likely due to column overloading and the influence of high concentrations of divalent ions. An ideal chromatographic peak has a Gaussian shape, is symmetrical, well separated from adjacent peaks, and exhibits a stable retention time. In this study, the occurrence of peak fronting was observed, which is characteristic of co-lumn overloading, as well as peak tailing resulting from the slow desorption of the analyte from the ion-exchange sites. As a consequence, overlapping of individual chro-matographic peaks is observed in the chromatograms, which complicates quantitative determination and may even hinder qualitative identification, as in the case of strontium ion. By comparing different integration methods available in the PeakNet software, it was determined that the tangential skim integration method was the most suitable for this study. Based on visual inspection of the chromatograms and statistical analysis of peak areas and heights (calculation of relative standard deviation for each ion), the most appropriate solutions for reliable determination of the composition of complex samples were identified for each sample. For Donat Mg mineral water, solution A3 with a dilu-tion factor of 60.73 was found to be optimal, while for seawater the optimal solution was A5 with a dilution factor of 23.80. The results obtained in this master’s thesis open possibilities for further research. It wo-uld be reasonable to include additional complex samples with different ionic composi-tions in order to verify whether they confirm the conclusions drawn in this study. redčenje kompleksni vzorci profili kromatografskih vrhov repatost dekonvolucija dilution complex samples chromatographic peak profiles tailing deconvolution true false false Slovenski jezik Angleški jezik Magistrsko delo/naloga 2026-03-06 12:30:02 2026-03-06 12:30:18 2026-03-13 14:19:47 0000-00-00 00:00:00 2026 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 25683 271653635 Smrekar_Katja_-_Vplivi_redcenja_mineralne_in_morske_vode_na_profile_vrhov_pri_kationski_kromatog.pdf Smrekar_Katja_-_Vplivi_redcenja_mineralne_in_morske_vode_na_profile_vrhov_pri_kationski_kromatog.pdf 1 B44E33F77F5121CD4EEE68AF8940EF18 a97cf30f62a07824d1356270550c89613b8536f56a8e942f5a2efb658f91411a 76be8976-194f-11f1-a1ba-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=229679 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0