Procjena mjerne nesigurnosti određivanja žive u dječjoj hrani atomskom apsorpcijskom spektrometrijom

master's thesis

• Title (english): Estimation of measurement uncertainty for the determination of mercury in baby food by atomic absorption spectrometry
• Author: Jasminka Pongračić Švarbić
• Mentor: Zorana Grabarić (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Chemistry and Biochemistry); (Laboratory for General and Inorganic Chemistry and Electroanalysis); Zagreb
• Defense date and country: 2008-01-29, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Mjerna nesigurnost rezultata određivanja žive u djecjoj hrani atomskom apsorpcijskom spektrometrijom procjenjena je „bottom-up” pristupom i iz podataka dobivenih validacijom metode. Prepoznate su i kvantificirane sastavnice mjerne nesigurnosti: nesigurnost odvage uzorka i nesigurnost otopine standarda žive, kojima su dodane nesigurnosti iskoristivosti, ponovljivosti i istinitosti. Mjernoj nesigurnosti rezultata najviše doprinosi nesigurnost iskoristivosti, dok su doprinosi nesigurnosti otopine standarda žive, ponovljivosti i istinitosti zanemarive. Ispitan je utjecaj matrice uzorka na apsorbanciju žive. Izradeni su kalibracijski pravci pomoću standarda žive različitih matrica. Statističkim testom dokazano je da nema značajne razlike izmedu nagiba kalibracijskih pravaca, odnosno da matrica uzorka nema utjecaja na apsorbanciju. Procjenjena mjerna nesigurnost određivanja žive u dječjoj hrani zadovoljava zahtjev propisan Uredbom Europske Zajednice. Maseni udjel žive određen je u 20 uzoraka dječje hrane analizatorom žive, AMA-254. U svim analiziranim uzorcima udjel žive je manji od zakonom dopuštenih količina.

Abstract (english)

The measurement uncertainty of the results of mercury determination in baby food was estimated following the bottom-up approach combined with the validation data. Uncertainty components were identified and quantified: uncertainty of weight of sample and uncertainty of mercury standard solution. Recovery, repeatibility and trueness were evaluated and added to the measurement uncertainty budget. The measurement uncertainty of the result is mostly influenced by uncertainty of recovery whereas contribution of uncertainty of mercury standard solution, repeatibility and truness being negligible. Influence of sample matrix on apsorbance was also examined. Different matrix mercury standards were used for calibration diagrams. Test-statistics showed no significant difference between calibration slopes and there is no influence on apsorbance by sample matrix, respectively. The evaluated measurement uncertainty in determining baby foods is in line with the EC Regulation. Mercury analyser AMA-254 was used for determination of mercury in 20 baby food samples. Mercury mass fraction values were found to be under legal limits for all of baby food samples.

• Keywords: atomska apsorpcijska spektrometrija; dječja hrana; mjerna nesigunost; živa
• Keywords (english): atomic absorption spectrometry; baby food; measurement uncertainty; mercury
• Language: croatian
• URN:NBN: urn:nbn:hr:159:185663
• Study programme: Title: Biotechnology; specializations in: Biochemical-Microbiology; Course: Biochemical-Microbiology; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer biotehnologije; smjer biokemijsko-mikrobiološki (diplomirani inženjer biotehnologije; smjer biokemijsko-mikrobiološki)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-09-04 13:47:12