Gas-liquid chromatography of fatty acids

R. Ackman, in Methods in Enzymology, Vol. XIV, J. Lowenstein, Editor (1969), Aia demic Press (New York), pp. 329-381. Gas-liquid chromatography of fatty acid esters... 

Table 4.6 Formation of geometrical isomers of y-linolenic acid in borage oil deodorized at different temperatures as determined by gas liquid chromatography of fatty acid isopropyl esters on a 30 m long DB-wax capillary column...

Woodford, F. P., and C. M. van Gent Gas-liquid chromatography of fatty acid methyl esters The carbon-number as a parameter for comparison of columns. J. Lipid Res. 1, 188 (1960). 

Total fatty acids were liberated by subjecting Salmonella minnesota Re lipopolysaccharide (or free lipid A) to acidic (4 N HC1, 5 h, 100°C) followed by alkaline (1 N NaOH, 1 h, 100°C) hydrolysis. After extraction (chloroform), the free fatty acids were converted into their methyl esters (diazomethane) and analysed by combined gas-liquid chromatography/mass spectrometry. Alternatively, the fatty acids of lipid A are transesterified by treatment of lipopolysaccharide with methanolic HC1 (2 N HC1 in water-free CHaOH, 18 h, 85°C). By these procedures the following fatty acids were identified (in approximate amounts relative to 2 moles glucosamine) dodecanoic (12 0, 1.1 mole), tetradecanoic (14 0, 0.8 mole), hexadecanoic (16 0, 0.9 mole), 2-hydroxytetradecanoic (2-OH-l4 0, 0.1 mole), and 3-hydroxytetradecanoic acid (3-OH-14 0, 4 moles). In total, therefore, approximately 7 moles of fatty acids are present per mole of lipid A backbone. The stereochemistry of the hydroxylated fatty acids was determined by gas-liquid chromatography of their diastereomeric methoxyacyl-L-phenylethylamide derivatives (24). It was found that 2-hydroxyte-tradecanoic acid possesses the-Ts), and the predominating 3-hydroxytetradecanoic acid the (R) configuration. 

Agate, A.D. and Vishniac, W., 1973. Characterisation of Thiobacillus species by gas-liquid chromatography of cellular fatty acids. Arch. Mikrobiol., 89 257—267. 

Johnson AR, Fogerty AC, Hood RL, Kozuharov S, Ford GL. Gas-liquid chromatography of ethyl ester artifacts formed during preparation of fatty acid methyl esters. J Lipid Res 1976 17 431—432. 

Oette, K., and Ahrens, E. H., Quantitative gas-liquid chromatography of short-chain fatty acids as 2-chloroethanol esters. Anal. Chem. 33, 1847-1851 (1961). 

The fatty acids obtained by hydrolysis of the single types of galactocerebrosides were analyzed by gas-liquid chromatography of, for example, their methyl esters. The main fatty acid in each group was... 

Standard Test Method for Fatty Acid Composition by Gas-Liquid Chromatography of Methyl Esters Oils and Oil Acids in Solvent-Redncible Paints Standard Test Method for Analysis of High-Pnrity n-Heptane and Isooctane by Capillary GC Standard Test Method for C8 Aromatic Hydrocarbons by GC... 

Moss, C.W. Dees, S.B. Guerrant, G.O. (1980). Gas-liquid chromatography of bacterial fatty acids with a fused-silica capillary column. Journal of Clinical Microbiology. Vol.l2, No.l, pp.127-130, ISSN 1098-660X. 

The fatty acid composition of oils is determined by the gas-liquid chromatography of the methyl esters of the fatty acids. Saponification (hydrolysis) followed by methylation is a... 

Plasma lipids were extracted by the method of Folch et alP- after the addition of an internal standard. Standards of phytanic acid were similarly treated. Constituent fatty acids were then converted to their methyl esters and analysed by gas-liquid chromatography. The phytanic acid content was calculated by comparison of the ratio of the peak heights of phytanate to internal standard for the test with those for the standard. Phytanic acid was also calculated as a percentage of all fatty acids from C,4 to Cjo by comparison of peak areas calculated from the product of peak height and retention time. The results are shown in Table 8.1 where it can be seen that phytanic acid accounts for 50% of the total plasma fatty acids. 

Ackmann, R. G., Eaton, C. A. and Sipos, J. C. (1975). Recent Advances in the Gas-Liquid Chromatography of Docosenoic 22 1) Fatty Acids of Marine and Rapeseed Oils. Technical Report No. 577. Environment Canada, Fisheries and Marine Service. 

Lambert, M. A. and Moss, C.W. (1972), Gas-liquid chromatography of short chain fatty acids on Dexsil 300 GC. J. Chromatogr.y 74,335. 

Another chromatographic method is pyrolysis/gas-liquid chromatography. The sample is mixed with P205 and heated to 400°C. This technique yields the chain length distribution of the fatty acids initially used [107],... 

Suzuki, M. and Lund, C.W. (1980) Improved gas-liquid chromatography for simultaneous determination of volatile fatty acids and lactic acid in silage. Journal of Agricultural and Food Chemistry 28,... 

Chlorella sorokiniana var. pacificensis were treated with 180 ppm O3 for 50 min in autotrophic media. Lipids were extracted by using Chloroform/methanol and prepared for gas-liquid chromatography (GLC) as described by Frederick and Heath (24). The average % concentration of fatty acids were calculated from 3 GLC runs in 5 separate samples. The O3/O2 column refers to ratios of average % concentration and represents standard deviation. Confidence Level was calculated by least squares analysis. 

NT544 Court, W. A., and J. G. Hendel. Determination of nonvolatile organic and fatty acids in flue-cured tobacco by gas liquid chromatography. J Chromatogr Sci 1978 16 314-317. 

C. S. Preparation of Methyl Esters of Fatty Acids for Gas-Liquid Chromatography Anal. Chem., 1961, 3, 1513. 

Gas-liquid chromatography separates volatile components of a mixture according to their relative tendencies to dissolve in the inert material packed in the chromatography column and to volatilize and move through the column, carried by a current of an inert gas such as helium. Some lipids are naturally volatile, but most must first be derivatized to increase their volatility (that is, lower their boiling point). For an analysis of the fatty acids in a sample of phospholipids, the lipids are first... 

Gas liquid chromatography is still the method of choice for the routine separation and tentative identification of common milk fatty acids, as well as for the resolution of the less abundant and less common acids. Although several hundred fatty acids are listed here and elsewhere as being present in milk, we remind the reader that not all of these have been rigorously identified. Some of the pitfalls in qualitative and quantitative GLC of milk fatty acids are discussed by Jensen et al. (1967) and those of fatty acids in general by Ackman (1980). 

Iverson, J. L., Eisner, J. and Firestone, D. 1965. Detection of trace fatty acids in fats and oils by urea fractionation and gas-liquid chromatography. J. Am. Oil Chem. Soc. 42, 1063-1068. 

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