Analysis of non‐polar lipids by HPLC on a diol column

Elfman‐Börjesson, Inger; Härröd, Magnus

doi:10.1002/jhrc.1240200911

Cited by 15 publications

(9 citation statements)

References 4 publications

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“…18 The use of a mild solvent (ethyl acetate) and zinc reduction procedure has greatly improved the ozonolysis-and hydrogenation-based technology and yielded a polyol with higher hydroxyl value and lower acidity content than that of the polyol previously made. The composition of the polyol was determined by an analysis protocol developed in our laboratory on the basis of the HPLC procedure developed by Elfman-Borjesson and Harrod 19 for the analysis of lipid derivatives. The polyol contained about 60%, 26%, and 5% (on a mass basis) of triol, diol, and monool, respectively.…”

Section: Resultsmentioning

confidence: 99%

Physical Properties of Polyurethane Plastic Sheets Produced from Polyols from Canola Oil

2007

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Polyurethane (PUR) plastic sheets were prepared by reacting polyols synthesized from canola oil with aromatic diphenylmethane diisocyanate. The properties of the material were measured by dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) as well as tensile properties measurements. The effect of stoichiometric balance (i.e., OH/NCO molar ratio) on the final properties was evaluated. The concentration of elastically active network chains (EANCs), ν e , of the polymer networks was calculated using rubber elasticity theory. The glass transition temperatures (T g ) for the plastic sheets with OH/NCO molar ratios of 1.0/1.0, 1.0/1.1, and 1.0/1.2 were found to be 23, 41, and 43°C, respectively. The kinetic studies of the degradation process of the PUR plastics showed three well-defined steps of degradation. The PUR plastic sheets with OH/NCO molar ratio 1.0/1.1 had the highest ν e , lowest number-average molecule weight between crosslinks, M C , and excellent mechanical properties, indicating that this is the optimum ratio in the PUR formulations.

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Section: Resultsmentioning

confidence: 99%

Physical Properties of Polyurethane Plastic Sheets Produced from Polyols from Canola Oil

2007

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“…The composition of the reaction mixture (FFA, TG, 1,3-DG, 1,2-DG, MG) was analyzed in an HPLC system (model SCL 6B; Shimadzu, Tokyo, Japan) equipped with a diol column (LiChrospher ® 100 diol, 5 µm, 4 × 125 mm; Merck) and an evaporative light-scattering detector (model 750/14; Applied Chromatography Systems Ltd., Macclesfield, Cheshire, England). The injected volume was 20 µL and the sample was eluted with n-heptane, acetic acid, and 2propanol at 55°C, as described elsewhere (25). An integration system (Kontron Instruments, Milano, Italy) was used for data collection and integration.…”

Section: Methodsmentioning

confidence: 99%

Synthesis of monoglycerides by glycerolysis of rapeseed oil using immobilized lipase

Elfman‐Börjesson

Härröd

1999

J Americ Oil Chem Soc

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Reaction conditions for the synthesis of monoglycerides (MG) by enzyme-catalyzed glycerolysis of rapeseed oil using Lipozyme ® IM have been studied. Silica gel was used to adsorb the glycerol to overcome the problems of low glycerol solubility in the organic phase. An experimental design was used where temperature, time, the ratio of silica gel to glycerol (w/w), the water activity (a w ), the isooctane concentration, and the ratio of glycerol to triglycerides (mol/mol) were varied. Response surface methodology was used to evaluate initial reaction rate and yield for the different products. The best yield of MG achieved under the studied conditions was 17.4% (mol fatty acid in substance/total mol fatty acid in mixture) (75°C, 20 h, silica gel/glycerol 2:1, a w = 0.17, 48% isooctane, glycerol/ triglycerides 6:1). The same conditions yielded 36.8% diglycerides, 13.6% free fatty acids (FFA), and 36.9% triglycerides. This is at the same level as the equilibrium yield. The yield of MG is low compared to the final yield achieved with solidphase glycerolysis. However, in solid-phase glycerolysis the reaction mixture becomes solid, and therefore the solid-phase process is not suitable for industrial application. The formation of FFA was very fast compared to the synthesis of MG. Equilibrium for FFA was reached within 2 h, and the yield was strongly affected by the a w . Increasing a w greatly increased the formation of FFA. In the a w ratio 0.06-0.3, the yield of FFA increased from 4 to 19% while the yield of MG was nearly unaffected. As FFA is an undesired product, it is important to keep the a w as low as possible.Paper no. J8908 in JAOCS 76, 701-707 (June 1999).

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“…The composition of the reaction mixture in terms of WE, FAME, and FOH were analyzed by HPLC on a Shimadzu SCL6B equipped with a diol column (Lichrospher 100 diol, 5 µm, 4 × 250 mm, Merck) and a Light Scattering Mass Detector 750/14 (ACS). The sample was eluted using a gradient of heptane, isopropanol, and acetic acid as described before (16).…”

Section: Methodsmentioning

confidence: 99%

Enzymatic synthesis of wax esters from rapeseed fatty acid methyl esters and a fatty alcohol

Hallberg

Daobin

Härröd

1999

J Americ Oil Chem Soc

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Wax esters were transesterified from fatty acid methyl esters of rapeseed and a fatty alcohol (1-hexadecanol, 16:0). The amounts of both the substrates were fixed to 0.1 mmol and an immobilized enzyme, Lipozyme, was used as catalyst. The experiment was performed following a statistic central composite design with five variables. The enzyme/lipid ratio was varied between 0.3-0.9 of the substrate weight and the enzyme was equilibrated to different water activities varying from 0.11 to 0.44. A temperature range of 50-80°C was investigated and the reaction time lasted up to 40 min. A solvent, isooctane, constituted 0-30% of the substrate weight. The first experimental series was performed in small closed test tubes. In the second series the caps of the test tubes were off to evaporate the methanol produced during the reaction. The highest initial reaction rate was 9.6 g wax esters /g enzyme · h. It appeared when: the enzyme/lipid ratio was low, 0.3, the temperature was high, 80°C; no isooctane was present; and the water activity was below 0.11. The initial reaction rate was independent of the caps on the test tubes. With the large amount of enzyme the yield of wax esters was above 70% after 10 min in both experimental series. In the reaction with caps, the reaction reached equilibrium at 83% after 20 min at 80°C. However, without caps the continuous evaporation of methanol increased the equilibrium constantly, and after 40 min at 80°C a yield of 90% was reached.

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Analysis of non‐polar lipids by HPLC on a diol column

Cited by 15 publications

References 4 publications

Physical Properties of Polyurethane Plastic Sheets Produced from Polyols from Canola Oil

Physical Properties of Polyurethane Plastic Sheets Produced from Polyols from Canola Oil

Synthesis of monoglycerides by glycerolysis of rapeseed oil using immobilized lipase

Enzymatic synthesis of wax esters from rapeseed fatty acid methyl esters and a fatty alcohol

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