Določanje acesulfama K in saharina v brezalkoholnih gaziranih pijačah

Mikše, Laura (avtor), Kočar, Drago (mentor)

V svojem diplomskem delu sem določila nekatera umetna sladila v brezalkoholnih gaziranih pijačah. Najprej sem optimizirala ločbo na inštrumentu HPLC. V različnih člankih sem poiskala metode za hkratno določanje sladil. Odločila sem se za določanje acesulfama K in saharina. Uporabila sem reverzno nepolarno stacionarno fazo C$_8$ in polarno mobilno fazo z gradientnim ločevanjem acetonitrila in 0,5 % fosforjeve(V) kisline. Volumen injiciranja je bil 10 µL in konstanten pretok 0,700 mL/min. Valovno dolžino detektorja sem nastavila na 220 nm, da sem lahko določila acesulfam K in saharin. Naredila sem umeritveno krivuljo v koncentracijskem območju med 1-50 mg/L za oba standarda. Določila sem mejo zaznave in mejo določljivosti. Meja zaznave je znašala 0,1 mg/L, meja določljivosti pa 0,3 mg/L. Nato sem določila koncentracije acesulfama K in saharina v štirih vzorcih brezalkoholnih gaziranih pijač. Acesulfam K je bil prisoten v vseh vzorcih, medtem ko sem saharin zaznala samo v enem vzorcu. Metoda je bila ustrezna, saj sem imela ponovljivost vzorcev primerljivo med sabo. Vse vrednosti RSD so bile pod 5 %. Koncentracije acesulfama K in saharina v vzorcih so bile zelo nizke in nižje od sprejemljivega dnevnega vnosa. Med eksperimentalnim delom sem zasledila tri dodatne kromatografske vrhove, ki sem jih želela identificirati. Na deklaraciji sem preverila možne spojine, ki bi lahko pripadale tem kromatografskim vrhovom: askorbinsko kislino, citronsko kislino, fenilalanin, jabolčno kislino, kalijev sorbat in kofein. Od teh spojin sem dokazala dve. To sta bili kalijev sorbat in kofein.

• Jezik: Slovenski jezik
• Ključne besede: acesulfam K, saharin, HPLC, brezalkoholne gazirane pijače
• Vrsta gradiva: Diplomsko delo/naloga
• Tipologija: 2.11 - Diplomsko delo
• Organizacija: FKKT - Fakulteta za kemijo in kemijsko tehnologijo
• Leto izida: 2024
• PID: 20.500.12556/RUL-160169
• COBISS.SI-ID: 205771523
• Datum objave v RUL: 22.08.2024

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Determination of sweeteners in non-alcoholic carbonated beverages

Izvleček

In my thesis, I identified some artificial sweeteners in soft drinks. First, I optimized the separation on the HPLC instrument. In various articles, I have found methods for simultaneous determination of sweeteners. I decided to determine acesulfame K and saccharin. I used reverse non-polar stationary phase C$_8$ and polar mobile phase with gradient separation of acetonitrile and 0,5 % phosphoric(V) acid. The injection volume was 10 µL and a constant flow rate of 0,700 mL/min. I set the wavelenght of the detector to 220 nm so that I could determine acesulfame K and saccharin. I made a calibration curve in the concentration range between 1-50 mg/L for both standards. I set the Limit of Detection and Limit of Quantitation. The Limit of Detection was 0,1 mg/L and the Limit of Quantitation was 0,3 mg/L. Then I determined the cocentrations of acesulfame K and saccharin in four samples of soft drinks. Acesulfame K was present in all samples, while saccharin was detected in only one sample. The method was appropriate, as I had the repeatability of the samples were comparable to each other. All RSD values were below 5 %. The concentrations of acesulfame K and saccharin in the samples were very low and below the acceptable daily intake. During the experimental work, I spotted 3 chromatographic peaks that I wanted to identify. I looked at the declaration for possible compounds that could belong to these chromatographic peaks: ascorbic acid, citric acid, phenylalanine, malic acid, potassium sorbate and caffeine. Of these compounds, I proved two. These were potassium sorbate and caffeine.

• Ključne besede: acesulfame K, saccharin, HPLC, non – alcoholic carbonated beverages