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Determination of low level trans unsaturation in physically refined vegetable oils by capillary GLC — Results of 3 intercomparison studies
Author(s) -
Buchgraber Manuela,
Ulberth Franz
Publication year - 2002
Publication title -
european journal of lipid science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.614
H-Index - 94
eISSN - 1438-9312
pISSN - 1438-7697
DOI - 10.1002/1438-9312(200212)104:12<792::aid-ejlt792>3.0.co;2-b
Subject(s) - chromatography , reproducibility , derivatization , degree of unsaturation , chemistry , rapeseed , linoleic acid , gas chromatography , capillary action , relative standard deviation , fatty acid , high performance liquid chromatography , organic chemistry , detection limit , food science , materials science , composite material
The analytical performance of capillary gas‐liquid chromatographic (GLC) methods for the quantitative determination of trans fatty acids (TFA) in physically refined rapeseed and soybean oils was evaluated by 3 intercomparison studies. The participants were allowed to use their own methodology regarding derivatization and GLC conditions and were not requested to follow a fixed method protocol. However, certain requirements relating to the separation efficiency (chromatographic separation of critical pairs) and the accuracy (validation of the response factors using a certified reference material) of the method(s) applied, had to be fulfilled. All 12 participating laboratories employed fused silica capillary columns coated with cyanopropyl polysiloxane for the separation of fatty acid methyl esters. Analytical precision was sufficient (relative standard deviation for reproducibility 13%) for the quantification of trans isomers occurring at levels >0.1 g/100 g in physically refined vegetable oils, i.e. trans isomers of linolenic acid. For TFA levels <0.1 g/100 g ( trans isomers of oleic and linoleic acid) precision dropped sharply (relative standard deviation for reproducibility >30%).