Determination of cis,cis-Methylene Interrupted Polyunsaturated Fatty Acids in Fats and Oils By Capillary Gas Chromatography

1986 ◽  
Vol 69 (1) ◽  
pp. 65-67
Author(s):  
Albert K Athnasios ◽  
Edward J Healy ◽  
Anthony F Gross ◽  
Gareth J Templeman
Keyword(s):  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Fatty Acid Methyl Esters ◽  
Capillary Column ◽  
Methyl Esters ◽  
Fats And Oils ◽  
Pufa Content ◽  
Acid Methyl ◽  
Relative Standard

Abstract A capillary gas chromatographic (CGC) method is described for the determination of cis,cis-methylene interrupted polyunsaturated fatty acids (cis-PUFA) in fats and oils. The sample is saponified and the liberated fatty acids are esterified to the corresponding methyl esters. The latter are analyzed by CGC using a 60M SP2340 capillary column. Area percent values for 9,12-cis,cis-C18:2 and 9,12,15-cis,cis,cis-C18:3 fatty acid methyl esters are summed to give the total cis-PUFA content. Gas chromatographic results agreed well with those obtained by an enzymatic lipoxygenase method at the 31-48% cis-PUFA levels with a correlation coefficient of 0.98. The method has a precision (relative standard deviation) of 0.33% at a 44.4% cis-PUFA level in margarine oil.

Direct ultrasound-assisted methylation of fatty acids in serum for free fatty acid determinations

2010 ◽  
Vol 88 (9) ◽  
pp. 898-905 ◽  
Author(s):  
Liyan Liu ◽  
Ying Li ◽  
Rennan Feng ◽  
Changhao Sun
Keyword(s):  
Mass Spectrometry ◽  
Fatty Acids ◽  
Gas Chromatography ◽  
Fatty Acid ◽  
Fatty Acid Methyl Esters ◽  
Methyl Esters ◽  
Ultrasonic Waves ◽  
Acid Methyl ◽  
Ultrasound Assisted

A method for simultaneous determination of 16 free fatty acids (FFAs) in serum is described. The method involves conversion of FFAs to fatty acid methyl esters (FAMEs) using the heat of ultrasonic waves followed by gas chromatography and mass spectrometry (GC–MS) analysis. Optimum levels of the variables affecting the yield of FAMEs were investigated. The results indicate that the optimal levels are 55 °C, 60 W, 10% H2SO4/CH3OH, and 50 min. Recoveries ranged from 85.32% to 112.11%, with a detection limit ranging from 0.03 to 0.08 μg mL–1. The linearity, using the linear correlation coefficient, was higher than 0.9914.

Determination of Dimers and Polymers in Heated Fats and Oils by Sublimation

1969 ◽  
Vol 52 (5) ◽  
pp. 958-963
Author(s):  
Anita Huang ◽  
David Firestone
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Methyl Esters ◽  
Methyl Esters ◽  
Fats And Oils ◽  
Dimer Acid ◽  
Fresh Vegetable ◽  
Oxidized Oil ◽  
Acid Methyl ◽  
Common Fatty Acid

Abstract A sublimation procedure is described for separating dimers and polymers from oxidized or polymerized fats and oils. Under the described conditions, involving sublimation at 90°C and 0.02–0.05 mm Hg pressure, common fatty acid methyl esters standards yielded 99–2100% sublimate, methyl esters of commercial vegetable oils yielded 97.4-99.2% sublimate, heated cottonseed oils yielded 64–83% sublimate, a thermal dimer acid yielded 1.0% sublimate, and laboratory-prepared oxidative dimers and polymers yielded 7.5% sublimate. A comparison of the sublimation procedure with urea adduction gave good correlations with thermally oxidized oil samples; however, with fresh vegetable oil or with samples consisting of predominantly thermal or oxidative dimers, sublimation gave more accurate results than urea adduction.

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