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Determination of selected metals in fruit compotes
Hauerlandová, Petra ; Vespalcová, Milena (referee) ; Diviš, Pavel (advisor)
This diploma thesis deals with the determination of some metals in fruit compotes packed in cans. There is described the production of fruit compotes and metal packaging legislation relating to the studied issues, the possibility of contamination of food packaging components, packaging corrosion, metal migration from packaging and techniques used for the analysis of metals in the food industry. Concentrations of metals in 14 different fruit compotes from a commercial network in the Czech Republic were determined by ICP-MS technique in the experimental part. Concentrations of metals were detected only in the juice of stewed fruit, because the juice is in direct contact with the surface of packaging, and metals are transferred first into it. The measured values were compared with the maximum permissible levels of metals in fruit compote determined by European legislation. In some cases there were found higher concentrations of tin, but other metals did not exceed the allowable amounts. Concentrations of metals in the compote varied depending on the kind of compote, which could be due to a different chemical composition of compotes depending on the origin of food and process of the fruit production, or a different cans coating material.
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Speciation analysis of arsenic-glutathione complexes by ion-pairing HPLC-ICP-MS
Zušťáková, Veronika ; Matoušek, Tomáš (advisor) ; Červený, Václav (referee)
The thesis has focused on the separation of arsenic-glutathione species using ion-pairing high performance liquid chromatography with detection by inductively coupled plasma mass spectrometry. Species were separated on chromatographic column Prodigy ODS (3) using an aqueous mobile phase containing 4.7mM tetrabutylammonium hydroxide (TBAH), 2mM malonic acid and 4% methanol at pH 5.85 in the isocratic mode. Simple arsenic species - arsenite (iAsIII), arsenate (iAsV) monomethylarsenic acid (MAsIII), monomethylarsenous acid (MAsV), dimethylarsenic acid (DMAsIII) and dimethylarsenous acid (DMAsV), which served as arsenic standards to determine retention times, were successfully separated under these conditions. Arsenic-glutathione complexes As(GS)3, MAs(GS)2 and DMAs (GS) were not successfully separated. These complexes provided peaks of simple arsenic species. Peak broadening was observed in the first analysis of As(GS)3 and MAs(GS)2 complexes, which disappeared in subsequent analyses. This broadening probably represents a residual of glutathion complex which disintegrated to single species. Powered by TCPDF (www.tcpdf.org)
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Speciation analysis of arsenic-glutathione complexes by ion-pairing HPLC-ICP-MS
Zušťáková, Veronika ; Matoušek, Tomáš (advisor) ; Červený, Václav (referee)
The thesis has focused on the separation of arsenic-glutathione species using ion-pairing high performance liquid chromatography with detection by inductively coupled plasma mass spectrometry. Species were separated on chromatographic column Prodigy ODS (3) using an aqueous mobile phase containing 4.7mM tetrabutylammonium hydroxide (TBAH), 2mM malonic acid and 4% methanol at pH 5.85 in the isocratic mode. Simple arsenic species - arsenite (iAsIII), arsenate (iAsV) monomethylarsenic acid (MAsIII), monomethylarsenous acid (MAsV), dimethylarsenic acid (DMAsIII) and dimethylarsenous acid (DMAsV), which served as arsenic standards to determine retention times, were successfully separated under these conditions. Arsenic-glutathione complexes As(GS)3, MAs(GS)2 and DMAs (GS) were not successfully separated. These complexes provided peaks of simple arsenic species. Peak broadening was observed in the first analysis of As(GS)3 and MAs(GS)2 complexes, which disappeared in subsequent analyses. This broadening probably represents a residual of glutathion complex which disintegrated to single species. Powered by TCPDF (www.tcpdf.org)
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Determination of selected metals in fruit compotes
Hauerlandová, Petra ; Vespalcová, Milena (referee) ; Diviš, Pavel (advisor)
This diploma thesis deals with the determination of some metals in fruit compotes packed in cans. There is described the production of fruit compotes and metal packaging legislation relating to the studied issues, the possibility of contamination of food packaging components, packaging corrosion, metal migration from packaging and techniques used for the analysis of metals in the food industry. Concentrations of metals in 14 different fruit compotes from a commercial network in the Czech Republic were determined by ICP-MS technique in the experimental part. Concentrations of metals were detected only in the juice of stewed fruit, because the juice is in direct contact with the surface of packaging, and metals are transferred first into it. The measured values were compared with the maximum permissible levels of metals in fruit compote determined by European legislation. In some cases there were found higher concentrations of tin, but other metals did not exceed the allowable amounts. Concentrations of metals in the compote varied depending on the kind of compote, which could be due to a different chemical composition of compotes depending on the origin of food and process of the fruit production, or a different cans coating material.
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