An on-line LC-GC method for the analysis of mono-, di-, and triacylglycerols in vegetable oil methyl esters has been developed. The concentrations of these components have turned out to be key parameters for the quality of diesel fuel substitutes. Separation of all classes of acylglycerols from the
Analysis of free and esterified sterols in vegetable oil methyl esters by capillary GC
β Scribed by Plank, Christina ;Lorbeer, Eberhard
- Publisher
- John Wiley and Sons
- Year
- 1993
- Tongue
- English
- Weight
- 507 KB
- Volume
- 16
- Category
- Article
- ISSN
- 0935-6304
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β¦ Synopsis
Abstract
The introduction of quality standards for vegetable oil methyl esters is gaining in importance due to their increased use as diesel fuel substitutes and as technical products. Free and esterified sterols, the main constituents of the unsaponifiable matter in vegetable oils, are recovered in vegetable oil methyl esters and may influence the technical properties of vegetable oil methyl ester products. A rapid gas chromatographic method for the qualitative and quantitative determination of free and esterified sterols in vegetable oil methyl esters has therefore been developed.
The concentration of the free sterols as well as their qualitative and quantitative composition and the concentration of the sterol esters have been determined in rape seed oil methyl ester samples by GCβFID. Prior to analysis, the free sterols were silylated with N,Oβbis(trimethylsilyl)trifluoroacetamide with 1% of trimethylchlorosilane; betulinol was used as an internal standard. Calibration was performed by analysis of standard solutions containing Ξ²βsitosterol, cholesteryl stearate, and betulinol. The reproducibility of the quantitative results has been evaluated by repeated injections of the same test solution and by repeated complete analysis of the same sample.
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