Quantitation of cis- and trans-Monounsaturated Fatty Acids in Dairy Products and Cod Liver Oil by Mass Spectrometry in the Selected Ion Monitoring Mode
| Autor: | Simone Hauff, Walter Vetter |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Spectrometry
Mass Electrospray Ionization Cod Liver Oil Sensitivity and Specificity Gas Chromatography-Mass Spectrometry Fatty Acids Monounsaturated chemistry.chemical_compound Isomerism Cheese Animals Humans Selected ion monitoring chemistry.chemical_classification Animal fat Chromatography Milk Human Goats food and beverages Fatty acid General Chemistry Cod liver oil Fish oil Oleic acid chemistry lipids (amino acids peptides and proteins) Dairy Products Gas chromatography–mass spectrometry General Agricultural and Biological Sciences Cis–trans isomerism |
| Zdroj: | Journal of Agricultural and Food Chemistry. 57:3423-3430 |
| ISSN: | 1520-5118 0021-8561 |
| DOI: | 10.1021/jf803665u |
| Popis: | Monounsaturated fatty acids (MUFAs) are important constituents of dietary fats. While cis-configurated isomers belong to the classic fatty acids of food, trans-fatty acids are suspected to pose a risk to human health. In either case, a thorough assessment of both positional and geometrical isomers of MUFAs is an important task in food and life sciences. For this purpose, a method suitable for routine analysis was developed. After lipid extraction and conversion of fatty acids into corresponding fatty acid methyl esters, cis and trans isomers of MUFAs were separated on silver-ion-impregnated cartridges. Fractions containing either cis- or trans-MUFAs were determined by gas chromatography-electron ionization mass spectrometry in the selected ion monitoring (GC/EI-MS-SIM) mode using [M-32](+) as quantification ions and [M-74](+) as well as M(+) as qualifier ions. A total of 14 MUFAs were available as reference standards, but a total of 40 MUFAs (22 cis and 18 trans isomers) were identified with high selectivity in samples of cheese, goat fat, human milk, and cod liver oil. The 18:1 and 16:1 isomers contributed most to both the cis- and trans-MUFAs. Application of internal standards allowed for the quantification of MUFAs only in the food samples. The amount of trans-fatty acids was determined to be 0.9- 4.3 g/100 g, with the lowest levels in human milk fat and the highest levels in Roquefort cheese. After exclusion of oleic acid, the concentrations of trans- and cis-MUFAs were at the same level in samples from ruminants and human milk fat. |
| Databáze: | OpenAIRE |
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