Študij stabilnosti različnih formulacij vodikovega peroksida

Andrejašič, Martina (author), Cerkovnik, Janez (mentor)

Vodikov peroksid je preprosta molekula, ki se uvršča med okolju prijazne spojine, saj pri razpadu nastaneta kisik in voda. Uporablja se za čiščenje odpadne in pitne vode, za sterilizacijo embalaže v prehrambni industriji, za dezinfekcijo v zdravstvu in farmaciji, kot belilno sredstvo, za razgradnjo industrijskih odpadnih snovi, kot gorivo, za sintezo farmacevtskih izdelkov in v kozmetiki. Zaradi raznolike uporabe ga pripravljajo v zelo različnih formulacijah. V prisotnosti nečistoč, kot so kovinski ioni in delci v zraku, pri povišani temperaturi, pri višjih pH vrednostih in izpostavljenosti sončni svetlobi, pride do katalitičnega eksotermnega razpada te molekule. Tudi voda deluje kot nečistoča, zato vodne raztopine z nižjo koncentracijo H2O2 hitreje razpadajo, kar se kaže kot glavna pomanjkljivost, da bi vodikov peroksid zadostil zahtevam za široko komercialno uporabo. Za izboljšanje stabilnosti H2O2 dodajajo različne stabilizatorje, največkrat stanate in fosfate, med temi pa sta v zadnjem času komercialno najpogosteje uporabljena ATMP in HEDP. V magistrskem delu sem spremljala stabilnost vodikovega peroksida različnih koncentracij v različnih medijih in raziskovala možnosti stabiliziranja z namenom ohraniti njegovo stabilnost v širokem koncentracijskem območju in v različnih topilih. Pripravila sem razredčene raztopine komercialnega vodikovega peroksida v zmeseh različnih alkoholov z vodo. Njihovo stabilnost sem spremljala pri sobni temperaturi, 40 in 60 °C tako, da sem spremljala koncentracijo vodikovega peroksida z jodometrično titracijo. Pri raziskavah vpliva stabilizatorjev na stabilnost vodikovega peroksida sem uporabljala 40 ut.% nestabilizirano surovo vodno raztopino vodikovega peroksida in iz nje pripravila razredčene raztopine z dodatki različnih organskih kislin kot stabilizatorjev. Njihov stabilizacijski učinek sem spremljala s t. i. stresnim testom stabilnosti raztopin vodikovega peroksida pri temperaturi 96 °C 16 ur s prej omenjeno volumetrično metodo. Raziskovala sem tudi možnost spektrofotometričnega določevanja tvorbe perokso kompleksov vodikovega peroksida z metiltrioksorenijem(VII) in tvorbe kompleksov med železovimi in tiocianatnimi ioni v prisotnosti vodikovega peroksida.

• Language: Slovenian
• Keywords: vodikov peroksid, določevanje koncentracije, stabilizacija, spektrofotometrija, titracija
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2022
• PID: 20.500.12556/RUL-137882
• COBISS.SI-ID: 116265987
• Publication date in RUL: 05.07.2022

Secondary language

• Language: English
• Title: Stability studies of different formulations of hydrogen peroxide

Abstract

Hydrogen peroxide is a simple molecule that is classified as an environmentally friendly compound because it decomposes to produce oxygen and water. It is used for wastewater and drinking water treatment, sterilization of packaging in the food industry, disinfection in health care and pharmacy, bleaching, decomposition of industrial waste, as a fuel and for the synthesis of drugs and cosmetics. Due to its wide range of applications, it is produced in a variety of formulations. In the presence of impurities such as metal ions and particles in the air, at elevated temperatures, higher pH values and in the presence of sunlight, catalytic exothermic decomposition of this molecule occurs. Water also acts as an impurity, so aqueous solutions with a lower H2O2 concentration decompose more rapidly, which proves to be a major disadvantage for hydrogen peroxide if it is to meet the requirements for widespread commercial use. To improve the stability of H2O2, various stabilizers are added, usually stanates and phosphates, of which ATMP and HEDP are the most commonly used. In my Master's thesis, I studied the stability of hydrogen peroxide at various concentrations in different media and explored stabilization over a wide range of concentrations in different solvents. Dilute solutions of commercial hydrogen peroxide in mixtures of various alcohols with water were prepared. Their stability was monitored at room temperature, 40 and 60 °C by monitoring the hydrogen peroxide concentration by iodometric titration. In studies on the effect of stabilizers on the stability of hydrogen peroxide, 40 wt% unstabilized aqueous solution of hydrogen peroxide was used and dilute solutions were prepared from it with the addition of various organic acids as stabilizers. Their stabilizing effect was monitored by the stress test for the stability of hydrogen peroxide solutions at 96 °C for 16 hours using the above volumetric method. I also investigated the possibility of spectrophotometric determination of the formation of peroxocomplexes of hydrogen peroxide with methyltrioxorenium(VII) and the formation of iron complexes by thiocyanate ions in the presence of hydrogen peroxide.

• Keywords: hydrogen peroxide, concentration determination, stabilization, spectrophotometry, titration