Usporedba atomske apsorpcijske spektrometrije i energetski disperzivne rendgenske fluorescencijske spektrometrije za određivanje sadržaja odabranih metala u uzorcima kave

master's thesis

• Title (english): Comparison of atomic absorption spectrometry and energy dispersive X-ray fluorescence spectrometry for determining the content of selected metals in coffee samples
• Author: Nikolina Hajduk
• Mentor: Jasna Jablan (mentor)
• Committee member: Jasna Jablan (predsjednik povjerenstva)
• Committee member: Suzana Inić (član povjerenstva)
• Committee member: Maja Bival Štefan (član povjerenstva)
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of analytical chemistry); Zagreb
• Defense date and country: 2022-07-18, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry; Analytic Chemistry

Abstract

Kava je najčešće konzumirani funkcionalni napitak i određivanje mineralnog sastava zrna kave može biti od velikog interesa za potrošače i proizvođače. Mineralni sastav kave razlikuje se s obzirom na geografsko porijeklo i vrstu kave. Cink, bakar, mangan i željezo su esencijalni mikronutrijenti koji imaju važnu ulogu u mnogim fiziološkim procesima. Budući da ih ljudski organizam ne može sintetizirati potrebno ih je unositi hranom ili suplementima. Glavni cilj ovog istraživačkog rada je usporediti AAS i EDXRF tehnike za određivanje sadržaja ispitivanih metala u odabranim uzorcima kave. Specifični ciljevi su validirati metodu plamene atomske apsorpcijske spektrometrije i odrediti sadržaj ispitivanih metala primjenom validirane metode u uzorcima kave koji su pripremljeni mokrom i suhom digestijom. Rezultati dobiveni dvjema tehnikama su uspoređeni prema parametrima metode, vremenu potrebnom za analizu te ekonomskom kriteriju. Analizom je utvrđeno da se rezultati dobiveni dvjema različitim analitičkim tehnikama podudaraju. Mokra digestija je brža metoda pripreme uzoraka kod AAS tehnike. Priprema uzoraka u obliku rastresitih prašaka je brža od pripreme peleta kod EDXRF tehnike. Prednost rastresitih prašaka je i što se mogu višekratno koristiti u analizama. EDXRF tehnika pokazala se bržom i ekološki prihvatljivijom. Analizom odabranih uzoraka kave je utvrđeno da su koncentracije ispitivanih metala u korelaciji s rezultatima iz prethodnih istraživanja te da postoje razlike u sadržaju bakra, cinka, željeza i mangana među različitim uzorcima.

Abstract (english)

Coffee is the most commonly consumed functional beverage and determining the mineral composition of coffee beans can be of great interest to consumers and producers. The mineral composition of coffee differs depending on the geographical origin and type of coffee. Zinc, copper, manganese and iron are essential micronutrients that play an important role in many physiological processes. Since the human body cannot synthesize them, it is necessary to take them in with food or supplements. The main goal of this research paper is to compare AAS and EDXRF techniques for determining the content of tested metals in selected coffee samples. The specific objectives are to validate the method of flame atomic absorption spectrometry and to determine the content of tested metals using a validated method in coffee samples prepared by wet and dry digestion. The results obtained by the two techniques were harmonized according to the parameters of the methods, the time required for analysis and the economic criteria. The analysis found that the results obtained by two different analytical techniques match. Wet digestion is a faster method of sample preparation in the AAS technique. The preparation of samples in the form of loose powders is faster than the preparation of pellets with the EDXRF technique. The advantage of loose powders is that they can be used multiple times in the analyses. The EDXRF technique has proven to be faster and more environmentally friendly. The analysis of selected coffee samples showed that the concentrations of the tested metals correlated with the results of previous studies and that there were differences in the content of copper, zinc, iron and manganese between different samples.

• Keywords: kava; cink; bakar; željezo; mangan; atomska apsorpcijska spektrometrija; energetski disperzivna rendgenska fluorescencijska spektrometrija
• Keywords (english): coffee; zinc; copper; iron; manganese; atomic absorption spectrometry; energy dispersive X-ray spectrometry
• Language: croatian
• URN:NBN: urn:nbn:hr:163:498327
• Study programme: Title: Pharmacy; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra farmacije (magistar/magistra farmacije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Embargoed access; Embargo expiration date: 2024-07-18
• Created on: 2022-07-20 08:37:28