A reversed-phase high-performance liquid chromatographic method is described for the separation o... more A reversed-phase high-performance liquid chromatographic method is described for the separation of individual classes of phospholipids into subfractions. The separation was achieved with isocratic elution using a Nucleosil-5 C18 column and a mobile phase consisting of methanol, acetonitrile and water. Three commercial C18 packing materials were evaluated before Nucleosil was chosen as the stationary phase. The compounds were detected with a combination of an UV detector and a light-scattering mass detector, which provided quantitative chromatograms reported for the first time. The mass detector also allowed location of the most relevant peaks of the UV chromatogram. Phosphatidylcholine and phosphatidylethanolamine species from egg, and phosphatidylcholine species from rat liver, were resolved into more than 20 peaks. The method can be applied to the separation of phospholipids from different biological sources.
Journal of the American Oil Chemists' Society, Oct 1, 1991
The compositions of positionssn-1, 2 and 3 of triacylglycerols can be determined by partial hydro... more The compositions of positionssn-1, 2 and 3 of triacylglycerols can be determined by partial hydrolysis with ethyl magnesium bromide, derivatization of the total products with (S)-(+)-1-(1-naphthyl)ethyl isocyanate and isolation of the diacyl-sn-glycerol urethane derivatives by chromatography on solid-phase extraction columns containing an octadecylsilyl phase. The diastereomericsn-1,2-and 2,3-diacylglycerol derivatives are separated by high-performance liquid chromatography on silica for determination of their
A highly sensitive and accurate reference method for determination of docosenoic acid (mainly eru... more A highly sensitive and accurate reference method for determination of docosenoic acid (mainly erucic acid, 22:1n-9) in different rapeseed oils is described. A fixed amount of [1-14C] erucic acid methyl ester (about 1 microgram) is added to a fixed amount of oil. After treatment with sodium methoxide/methanol reagent and extraction with hexane, the amount of unlabeled erucic acid is determined from the ratio between the recordings at m/e 320 and m/e 322 obtained after analysis with a combined gas chromatograph-mass spectrometer equipped with an MID (multiple ion detector). The two ions used correspond to the M-32 peak in the mass spectrum of unlabeled and [1-14C] labeled erucic acid methyl ester. The relative standard deviation of the method is about 1.8%. The method was compared with a gas chromatographic method for determination of erucic acid.
Plant lecithins are obtained in the degumming process in the production of vegetable oils. They a... more Plant lecithins are obtained in the degumming process in the production of vegetable oils. They are normally by-products and the crude material consists of a complex mixture of lipids and other components such as pigments and carbohydrates2. The use of lecithins in food is mainly for functional resons, e.g. as emulsifiers. Multicomponent natural products such as the lecithins are also multifunctional and applications are often found through tedious testing procedures. In specific applications it may even be necessary to test production batches before delivery due to batch-to-batch variations which could significantly change the properties of the product in question.
A reversed-phase high-performance liquid chromatographic method is described for the separation o... more A reversed-phase high-performance liquid chromatographic method is described for the separation of individual classes of phospholipids into subfractions. The separation was achieved with isocratic elution using a Nucleosil-5 C18 column and a mobile phase consisting of methanol, acetonitrile and water. Three commercial C18 packing materials were evaluated before Nucleosil was chosen as the stationary phase. The compounds were detected with a combination of an UV detector and a light-scattering mass detector, which provided quantitative chromatograms reported for the first time. The mass detector also allowed location of the most relevant peaks of the UV chromatogram. Phosphatidylcholine and phosphatidylethanolamine species from egg, and phosphatidylcholine species from rat liver, were resolved into more than 20 peaks. The method can be applied to the separation of phospholipids from different biological sources.
Journal of the American Oil Chemists' Society, Oct 1, 1991
The compositions of positionssn-1, 2 and 3 of triacylglycerols can be determined by partial hydro... more The compositions of positionssn-1, 2 and 3 of triacylglycerols can be determined by partial hydrolysis with ethyl magnesium bromide, derivatization of the total products with (S)-(+)-1-(1-naphthyl)ethyl isocyanate and isolation of the diacyl-sn-glycerol urethane derivatives by chromatography on solid-phase extraction columns containing an octadecylsilyl phase. The diastereomericsn-1,2-and 2,3-diacylglycerol derivatives are separated by high-performance liquid chromatography on silica for determination of their
A highly sensitive and accurate reference method for determination of docosenoic acid (mainly eru... more A highly sensitive and accurate reference method for determination of docosenoic acid (mainly erucic acid, 22:1n-9) in different rapeseed oils is described. A fixed amount of [1-14C] erucic acid methyl ester (about 1 microgram) is added to a fixed amount of oil. After treatment with sodium methoxide/methanol reagent and extraction with hexane, the amount of unlabeled erucic acid is determined from the ratio between the recordings at m/e 320 and m/e 322 obtained after analysis with a combined gas chromatograph-mass spectrometer equipped with an MID (multiple ion detector). The two ions used correspond to the M-32 peak in the mass spectrum of unlabeled and [1-14C] labeled erucic acid methyl ester. The relative standard deviation of the method is about 1.8%. The method was compared with a gas chromatographic method for determination of erucic acid.
Plant lecithins are obtained in the degumming process in the production of vegetable oils. They a... more Plant lecithins are obtained in the degumming process in the production of vegetable oils. They are normally by-products and the crude material consists of a complex mixture of lipids and other components such as pigments and carbohydrates2. The use of lecithins in food is mainly for functional resons, e.g. as emulsifiers. Multicomponent natural products such as the lecithins are also multifunctional and applications are often found through tedious testing procedures. In specific applications it may even be necessary to test production batches before delivery due to batch-to-batch variations which could significantly change the properties of the product in question.
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Papers by Bengt Herslöf