Določanje vodikovega peroksida v alkalnem mediju

Škufca, Nastja (author), Kolar, Mitja (mentor)

Vodikov peroksid se pogosto uporablja v higienskih in dezinfekcijskih sredstvih, belilih in kot konzervans v hrani. V človeškem organizmu lahko v visokih koncentracijah povzroča različne bolezni in tvorbo hidroksilnih radikalov, ki so znani kot kancerogeni. Zato je natančno in zanesljivo določanje vodikovega peroksida zelo pomembno. Kot učinkovite naprave za določanje vodikovega peroksida so se izkazali elektrokemijski senzorji. V okviru moje diplomske naloge sem se ukvarjala z razvojem amperometričnega senzorja za določanje koncentracije vodikovega peroksida. V sklopu meritev sem optimizirala komercialno SPE elektrodo in preučevala različne bazične oz. puferske raztopine. Za doseg najboljšega delovanja elektrode sem izvedla modifikacijo elektrodne površine, pri tem sem spreminjala razmerje materialov pri pripravi disperzije za modifikacijo in količino nanosa te disperzije. Spremljala sem odziv in občutljivost elektrode na znane dodatke standardne raztopine vodikovega peroksida. Na podlagi teh rezultatov sem določila na kakšen način je najbolje pripraviti elektrodo in izbrala najbolj primeren medij za določanje vodikovega peroksida v realnem vzorcu. Med preiskovanimi raztopinami se je najbolje obnesla raztopina KOH. Nato sem pripravila umeritveno krivuljo za dodatke standardne raztopine vodikovega peroksida v raztopini KOH in določila LOD. Razvit senzor sem nato uporabila pri analizi realnega vzorca vodikovega peroksida sintetiziranega v 0,1 M raztopini KOH.

• Language: Slovenian
• Keywords: elektrokemijski senzor, vodikov peroksid, amperometrija, modifikacija
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2023
• PID: 20.500.12556/RUL-149533
• COBISS.SI-ID: 163780099
• Publication date in RUL: 07.09.2023

Secondary language

• Language: English
• Title: Determination of hydrogen peroxide in alkaline medium

Abstract

Hydrogen peroxide is widely used as a sanitizer, disinfectant, bleach, and as a preservative in food. High concentrations of hydrogen peroxide in human body can cause cellular damage and form hydroxyl radicals known to be involved in carcinogenesis. Therefore, accurate and reliable determination of hydrogen peroxide is critical. Electrochemical sensors have proven to be effective devices for the determination of hydrogen peroxide. In this work, I focused on the development of an amperometric sensor for the determination of hydrogen peroxide concentration. For the measurements, I focused on optimizing the electrode and studying different basic or buffer solutions. To achieve the best electrode performance, I optimized the modification of the electrode surface by adjusting the ratio of deposited materials in the dispersion poured on the electrode surface. The response and sensitivity of the electrode to known additives of standard hydrogen peroxide solution were monitored. Based on these results, I selected the best electrode preparation method and the most suitable solution for the determination of hydrogen peroxide in real samples. Of the solutions studied, the KOH solution showed the best performance. Therefore, a calibration curve for hydrogen peroxide in KOH solution was prepared and the detection limit (LOD) was calculated. The developed sensor was used for the analysis of real samples of hydrogen peroxide synthesized in 0,1 M KOH solution.

• Keywords: electrochemical sensor, hydrogen peroxide, amperometry, modification