Improved gas chromatographic method for the determination of the individual free fatty acids in cheese using a capillary column and a PTV injector

1992 ◽  
Vol 33 (7-8) ◽  
pp. 351-355 ◽  
Author(s):  
M. Juárez ◽  
M. A. de la Fuente ◽  
J. Fontecha
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Chromatographic Method ◽  
Capillary Column ◽  
The Individual ◽  
Gas Chromatographic Method

Capillary Column Gas Chromatographic Determination of Trace Residues of the Herbicide Chlorsulfuron in Agricultural Runoff Water

1987 ◽  
Vol 70 (4) ◽  
pp. 745-748
Author(s):  
Uaz Ahmad
Keyword(s):  
Gas Chromatography ◽  
Chromatographic Method ◽  
Capillary Column ◽  
Methylene Chloride ◽  
Chromatographic Determination ◽  
Agricultural Runoff ◽  
Runoff Water ◽  
Florisil Column ◽  
Gas Chromatographic Method

Abstract A capillary column gas chromatographic method is described for determining parts-per-trillion (ppt) levels of chlorsulfuron in agricultural runoff water. The water sample is acidified with acetic acid and extracted with methylene chloride. The chlorsulfuron in the extract is derivatized to its monomethyl derivative. After Florisil column cleanup, the methylated chlorsulfuron is determined by electron-capture gas chromatography. Recovery of chlorsulfuron from fortified water samples is greater than 80%. Detection limit of the method is 25 ng chlorsulfuron/L water (25 ppt). There are 2 reaction sites on the chlorsulfuron molecule, both of which are susceptible to methylation leading to monomethyl chlorsulfuron and dimethyl chlorsulfuron. A procedure is described to methylate selectively the sulfonamide nitrogen of chlorsulfuron.

Liquid Chromatographic Method for Quantitative Determination of Free Fatty Acids in Butter

1984 ◽  
Vol 67 (4) ◽  
pp. 718-721 ◽  
Author(s):  
Alan W Reed ◽  
Hilton C Deeth ◽  
Donald E Clegg
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Chromatographic Method ◽  
Water System ◽  
Internal Standard ◽  
Detection Range ◽  
Water Solvent ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method has been developed for the determination of free fatty acids in butter. The fatty acids are converted to the p-bromophenacyl esters, via a crown ether-catalyzed reaction, without separation from the other butter components. The esters are separated on a Cis-bonded silica column by using an acetonitrile-water solvent gradient and quantitated using the ester of heptadecanoic acid as internal standard. Cu, and C ,S:i co-elute in the acetonitrile-water system but are separated using an isocratic methanol-acetonitrile-water system. Limits of detection range from 7 ng for butyric acid to 45 ng for linoleic acid. The average coefficient of variation (n = 10) for 10 free fatty acids from,a butter was 5.83%.

scholarly journals Fatty acids and composition of their important groups in milk fat of Czech Pied cattle

2011 ◽  
Vol 51 (No. 5) ◽  
pp. 181-188 ◽  
Author(s):  
M. Pešek ◽  
E. Samková ◽  
J. Špička
Keyword(s):  
Fatty Acids ◽  
Palmitic Acid ◽  
Dairy Cows ◽  
Milk Fat ◽  
Chromatographic Method ◽  
Monounsaturated Fatty Acids ◽  
Fat Composition ◽  
Total Proportion ◽  
The Individual ◽  
Gas Chromatographic Method

In 2003, 2004 and 2005 milk fat composition was determined three times in 55 dairy cows of Czech Pied cattle housed in a byre with stanchions and fed under conditions usual on Czech production farms. Fatty acids were determined by a gas chromatographic method, 26 acids out of the total 37 acids observed in chromatograms were identified. The highest proportions were observed for palmitic acid (29.25 ± 2.98%), oleic acid (24.47 ± 3.27%), myristic acid (12.14 ± 1.80%) and stearic acid (8.91 ± 2.44%). The proportions of saturated, unsaturated and monounsaturated fatty acids were 64.71 ± 4.18, 31.96 ± 4.20 and 27.45 ± 3.42% of total acids, respectively. The total proportion of nutritionally undesirable lauric, myristic and palmitic acid was 45.26 ± 4.77%, while that of the desirable group of polyunsaturated fatty acids was 4.51 ± 1.09%. The observed relatively wide ranges of the individual groups of fatty acids indicate that it is possible to improve the milk fat composition in Czech Pied cows.  

A method for the quantitative determination of individual free fatty acids in milk by ion exchange resin adsorption and gas-liquid chromatography

1983 ◽  
Vol 50 (3) ◽  
pp. 321-329 ◽  
Author(s):  
Eric C. Needs ◽  
Graeme D. Ford ◽  
A. Jane Owen ◽  
Brian Tuckley ◽  
Malcolm Anderson
Keyword(s):  
Fatty Acids ◽  
Liquid Chromatography ◽  
Free Fatty Acids ◽  
Exchange Resin ◽  
Ion Exchange Resin ◽  
Gas Liquid Chromatography ◽  
Internal Standards ◽  
Resin Adsorption ◽  
The Individual

SummaryA quantitative method for rapid routine analysis of individual free fatty acids (FFA) in milk was developed. Lipid was extracted from milk in ether and FFA were recovered by shaking the extract with anion exchange resin Amberlyst 26. The resin-bound FFA were methylated directly and the individual acids quantified, using internal standards, by gas-liquid chromatography. The properties of the resin were measured. The validity of the method was established by extraction of FFA mixtures and milk. Individual acids were, on average, found to be within 6% of the actual concentration present in the mixture. An average coefficient of variation of 4·3% was achieved for the major individual fatty acids on repeated extraction of a single milk sample.

Gas chromatographic method for determining free fatty acids in cheese

1988 ◽  
Vol 25 (2) ◽  
pp. 87-90 ◽  
Author(s):  
M. C. Martin-Hernández ◽  
L. Alonso ◽  
M. Juárez ◽  
J. Fontecha
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Chromatographic Method ◽  
Gas Chromatographic Method
Sign in / Sign up

Export Citation Format

Share Document