Avtomatizacija potenciometričnih titracij za določanje kislin v tehnoloških procesih

Košir, Patrik (author), Kolar, Mitja (mentor)

V diplomskem delu smo študirali različne potenciometrične titracije in njihovo uporabnost v različnih tehnoloških procesih, predvsem v živilski industriji (pecilni prašek, soda bikarbona, citronska kislina, jedilni kis, vinski kamen, kola,…). Primerjali smo rezultate, dobljene s klasično titracijo z bireto in s titracijo z uporabo avtomatskega titratorja ter ugotavljali odstopanja in napake določitev. Rezultati so pokazali, da dajeta obe vrsti titracij točne in natančne rezultate, ki so med seboj dobro primerljivi. Obe vrsti titracij lahko uporabljamo za določanje vsebnosti HCl, H3PO4, CH3COOH itd. Za analize realnih vzorcev pa se, zaradi ne tako izrazitega preskoka, bolje obnesejo avtomatske titracije (tudi določitev ekvivalentne točke je lažja zaradi manjših dodanih volumnov v bližini ekvivalentne točke). Ugotovili smo tudi, da so za titracije poznanih vzorcev še vedno najboljša izbira klasične titracije z bireto, saj so hitre, natančne in najcenejše. V primeru razredčenih in nepoznanih vzorcev so boljša izbira avtomatske titracije, v kolikor pa imamo opravka z zmesmi več kislin, pa je določitev bolj smiselno opraviti z drugo metodo (v mojem primeru atomsko emisijsko spektroskopijo), saj je iz titracijske krivulje težko pravilno določiti množino posamezne kisline.

• Language: Slovenian
• Keywords: potenciometrija, titracije, titracijska krivulja, ekvivalentna točka, atomska emisijska spektroskopija
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2019
• PID: 20.500.12556/RUL-109199
• COBISS.SI-ID: 1538298819
• Publication date in RUL: 26.08.2019

KOŠIR, Patrik, 2019, Avtomatizacija potenciometričnih titracij za določanje kislin v tehnoloških procesih [online]. Bachelor’s thesis. [Accessed 11 April 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=109199

Secondary language

• Language: English

Abstract

The field of my graduation work was study of different potentiometric titrations and their partial validation. I evaluated the purpose of the potentiometric titrations for different tehnological systems, mainly in the food processing industry (baking powder, baking soda, citric acid, eating vinegar, wine stone). I compared the results obtained by classical titration (manual titrations use a glass burette) and automatic titration and noted deviations and errors of determinations. The differencies between both methods as well as advantages and disadvantages of both titration methods were identified. As can be seen from the results, both titration methods reproduce the accurate and precise results, which are well comparable to each other. I would like to point out that both titration methods are suitable for laboratory samples (solutions of Hydrochloric acid (HCl), solutions Glacial acetic acid (CH3COOH), solution of Phosphoric acid (H3PO4), etc. In case of real samples, the better choice is automatic titration method because it determines the exact volume at the end-point. It can be concluded that in case of known composition of samples, the best choice is classical titration (use a glass burette) due to the analysis speed, accuracy and costs. In case of diluted samples and unknown samples, it is better to use automatic titrations. If we have the samples which include mixtures of several acids, it will be very difficult from the titration curve to calculate the value of individual acid. According to the above-mentioned facts it can be concluded that for the samples which include mixtures of several acids, the correct choice of the method will be atomic emission spectroscopy.

• Keywords: potentiometry, titration, titration curve, equivalent point, atomic emission spectroscopy