Gas Chromatography of Free Fatty Acids, II. Packed Columns with Inert Support Material

1963 ◽  
Vol 1 (9) ◽  
pp. 17-18 ◽  
Author(s):  
F. J. Kabot ◽  
L. S. Ettre
Keyword(s):  
Fatty Acids ◽  
Gas Chromatography ◽  
Free Fatty Acids ◽  
Packed Columns ◽  
Support Material ◽  
Inert Support

Gas Chromatography of Free Fatty Acids.

1964 ◽  
Vol 36 (12) ◽  
pp. 2244-2248 ◽  
Author(s):  
J. G. Nikelly
Keyword(s):  
Fatty Acids ◽  
Gas Chromatography ◽  
Free Fatty Acids

scholarly journals Potential Interference by Free Fatty Acids in Determination of Tricyclazole in Brown Rice by Gas Chromatography with Flame Thermionic Detection

1996 ◽  
Vol 79 (6) ◽  
pp. 1471-1476
Author(s):  
Yukari Tsumura ◽  
Yumiko Nakamura ◽  
Yasuhide Tonogai ◽  
Tadashi Shibata
Keyword(s):  
Fatty Acids ◽  
Gas Chromatography ◽  
Linoleic Acid ◽  
Free Fatty Acids ◽  
Brown Rice ◽  
Peak Height ◽  
Silica Cartridge ◽  
Limit Of Quantitation ◽  
First Time

Abstract A convenient method is described for the determination of tricyclazole in brown rice, and the interference of free fatty acids with flame thermionic detection (FTD) is reported for the first time. Brown rice is extracted with acetone, the extract is filtered, and the filtrate is evaporated. To the residue is added 10% (w/v) NaCI solution, and the mixture is extracted with ethyl acetate. The extract is charged on a Sep-Pak Plus silica cartridge. Free fatty acids are removed from the rice by washing with diethyl ether, and tricyclazole is eluted with acetone-n-hexane (1 + 1). Tricyclazole is determined on a DB-1 capillary column by gas chromatography with FTD (GC–FTD). Linoleic acid and oleic acid, which have essentially the same retention time as tricyclazole, cannot be detected by FTD. Thus, without the Sep- Pak Plus silica cleanup, the peak height of tricyclazole in the chromatogram decreased, the extent depending on the concentration of linoleic acid, n-Hexane–acetonitrile partitioning was not used for cleanup because it could not remove 50% of the free fatty acids. Recoveries (mean ± standard deviation, n = 5) of tricyclazole from rice fortified at 2 and 0.1 ppm were 90.5 ±9.4% and 81.3±10.6%, respectively. The limit of quantitation was 0.05 ppm.

Solena amplexicaulis (Cucurbitaceae) flower surface wax influencing attraction of a generalist insect herbivore, Aulacophora foveicollis (Coleoptera: Chrysomelidae)

2016 ◽  
Vol 36 (02) ◽  
pp. 70-81 ◽  
Author(s):  
Amarnath Karmakar ◽  
Anandamay Barik
Keyword(s):  
Fatty Acids ◽  
Gas Chromatography ◽  
Free Fatty Acids ◽  
Economic Losses ◽  
Undecanoic Acid ◽  
Generalist Herbivore ◽  
Solena Amplexicaulis ◽  
Aulacophora Foveicollis ◽  
Surface Waxes ◽  
Nonadecanoic Acid

AbstractAulacophora foveicollisLucas causes economic losses to creeping cucumber [Solena amplexicaulis(Lam.) Gandhi] growers in India and Bangladesh because adults feed on the leaves and flowers causing death of the plant. The insect is a generalist herbivore as it also causes damage to pumpkin, bottle gourd, sponge-gourd and gac fruit production by feeding on leaves and flowers of these plants. At present, insects are controlled with insecticides, which are harmful to human health and the environment. We studied the behavioural responses of adultA. foveicollisto flower surface waxes and synthetic compounds mimicking flower surface waxes to determine their potential for monitoring this pest. The gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detector (GC-FID) analyses ofS. amplexicaulisflower (50 g) surface waxes indicated presence of 17.9 and 3.1 mg alkanes and free fatty acids, respectively. Seventeenn-alkanes fromn-C15ton-C34and 16 free fatty acids from C10:0 to C22:0 were detected in the flower surface waxes. Heptacosane was predominant amongn-alkanes representing 2748.1 µg; whereas, pentadecanoic acid was the major fatty acid accounting for 466.6 µg.Aulacophora foveicolliswere attracted to the flower surface waxes at concentrations of 4 to 8 μg/ml, as demonstrated by a Y-tube olfactometer bioassay. Using a dose response bioassay, the insect was shown to be attracted to individual synthetic pentadecane, heptacosane, nonacosane, undecanoic acid and nonadecanoic acid at 0.70, 0.70, 1.20, 1.60 and 1.40 µg/ml, respectively. The insect displayed highest attraction to a synthetic mixture of 0.70, 1.23, 0.77, 0.84, 0.94 and 0.74 µg/ml of pentadecane, heptacosane, nonacosane, undecanoic acid, lauric acid and nonadecanoic acid, respectively, and hence, this combination might be used for insect pest management such as in baited traps.

Effect of External Lipids on the Process of Wool Yellowing

1992 ◽  
Vol 62 (10) ◽  
pp. 580-585 ◽  
Author(s):  
Elżbieta Wojciechowska ◽  
Anna Pielesz ◽  
Andrzej Wlochowicz
Keyword(s):  
Fatty Acids ◽  
Gas Chromatography ◽  
Free Fatty Acids ◽  
Lipid Composition ◽  
Ester Fraction

We have made an analysis of the lipids deposited on the surface of wool staple fibers divided into tip and base sections prior to investigation. The analysis is limited to a determination of free fatty acids and the ester fraction by gas chromatography and mass spectrography. The findings show that the changes in lipid composition, both quantitative and qualitative, depend on the location from which the lipids have been sampled.

scholarly journals 106 Cellulose Coatings Reduce Rancidity of Pecans

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 407B-407
Author(s):  
E.A. Baldwin ◽  
Bruce W. Woods
Keyword(s):  
Fatty Acids ◽  
Gas Chromatography ◽  
Free Fatty Acids ◽  
Unsaturated Fatty Acids ◽  
Oxidative Cleavage ◽  
Carya Illinoinensis ◽  
Edible Coatings ◽  
Ambient Conditions ◽  
Off Flavors ◽  
Hydrolysis Of

Pecans (Carya illinoinensis) are full of unsaturated fatty acids, which are subject to oxidative cleavage. This results in the development of rancid off-flavors, which render the nuts unmarketable. For this reason, pecans must be stored under costly refrigerated conditions. Furthermore, pecans usually undergo retail distribution and marketing at ambient conditions, which promote development of off-flavors. Application of cellulose-based edible coatings reduced off-flavor, and improved overall flavor scores while adding shine to the nuts during 14 months of storage under ambient conditions. Development of rancidity involves hydrolysis of glycerides into free fatty acids, oxidation of double bonds of unsaturated fatty acids to form peroxides and then autooxidation of the free fatty acids once the peroxides reach a sufficient level to perpetuate this reaction. One of the products of autooxidation is hexanal which is, thus, a good indicator of rancidity. Analysis of pecans by gas chromatography revealed that hexanal levels were reduced in coated nuts by 5- to over 200-fold compared to uncoated controls, depending on the coating treatment. Some of the coating treatments affected nut color, but overall flavor and appearance were improved by certain formulations.

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