Semimicro determination of total fatty acids and unsaponifiable matter

1960 ◽  
Vol 37 (9) ◽  
pp. 415-418 ◽  
Author(s):  
James H. Benedict
Keyword(s):  
Fatty Acids ◽  
Unsaponifiable Matter ◽  
Total Fatty Acids

Determination of lipids, including medium-chain fatty acids, in human feces.

1982 ◽  
Vol 28 (4) ◽  
pp. 603-605 ◽  
Author(s):  
W Esteves ◽  
L A Soares ◽  
L Hartman ◽  
A S Pereira
Keyword(s):  
Fatty Acids ◽  
Unsaponifiable Matter ◽  
Potassium Hydroxide ◽  
Total Lipids ◽  
Human Feces ◽  
Medium Chain ◽  
Medium Chain Fatty Acids ◽  
Hexane Solution ◽  
Chain Fatty Acids

Abstract In this method for determining fecal lipids, feces are saponified with ethanolic potassium hydroxide, the ethanol is evaporated, and the acidified residue extracted with hexane. An aliquot of the hexane solution is then titrated with ethanolic sodium hydroxide, the solvents are evaporated, and the residue (soaps and unsaponifiable matter) is weighed. The unsaponifiable matter is extracted with acetone and determined gravimetrically. The method thus permits the determination of milli-equivalents of fatty acids, total lipids, and fatty acids in one sample and is applicable to feces containing medium-chain fatty acids and their triglycerides.

Analysis for Crude Fatty Acids (Total Fatty Acids and Unsaponifiable Matter) in Feed Grade Fats: Report of the Joint AOAC-AOCS Committee on the Analysis of Feed Grade Fats

1972 ◽  
Vol 55 (4) ◽  
pp. 846-850
Author(s):  
F W Quackenbush
Keyword(s):  
Fatty Acids ◽  
Unsaponifiable Matter ◽  
Low Grade ◽  
Yellow Grease ◽  
Chicken Fat ◽  
Liquid Liquid Extraction ◽  
Insoluble Material ◽  
Collaborative Test ◽  
Separate Fraction ◽  
Total Fatty Acids

A method for analysis of total fatty acids plus unsaponifiable matter that employs a newly designed liquid-liquid extraction appar at us has given satisfactory results i n a collaborative test. Seven collaborators analyzed samples of prime tallow, chicken fat, yellow grease, 2 samples of cottonseed fatty acids, and 2 samples of acidulated soap stock. The method permits removal of hexane-soluble unsaponifiable matter as a separate fraction. The 3 animal fat samples yielded results which were close to the theoretical value, 95.6, for a triglyceride with 85% C18 and 15% C16 fatty acids. The 4 samples of hydrolyzed vegetable fats gave lower values, probably because of the presence of dark insoluble material. Nevertheless, the method seems to be acceptable for analysis of such low grade samples. The method has been adopted as official first action.

QUANTITATIVE ANALYSIS OF FATTY ACIDS IN VULCANIZED STYRENE–BUTADIENE RUBBER BY THERMAL DESORPTION AND THERMALLY ASSISTED HYDROLYSIS AND METHYLATION-GC/MS

2014 ◽  
Vol 87 (3) ◽  
pp. 516-525 ◽  
Author(s):  
Atsushi Watanabe ◽  
Chu Watanabe ◽  
Robert Freeman ◽  
Mari Nakajima ◽  
Norio Teramae ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Thermal Desorption ◽  
Methyl Esters ◽  
Analytical Data ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Relative Standard ◽  
Total Fatty Acids ◽  
Styrene Butadiene

ABSTRACT Determination of stearic acid in rubber is very important from the viewpoint of quality control of products. In place of the conventional liquid-phase extraction procedures for the analysis of additives in rubber, stearic and palmitic acids in vulcanized styrene–butadiene rubber (SBR) samples were directly analyzed in the solid state by thermal desorption (TD)–gas chromatography (GC)/mass spectrometry (MS) and thermally assisted hydrolysis and methylation (THM)–GC/MS. It was found that the precision of analytical data was only fair in the TD-GC/MS analysis, with 7.8% relative standard deviation (RSD), because of the interaction between the polar fatty acids and basic sites in the GC chromatographic system. On the other hand, THM-GC/MS, in which the fatty acids are derivatized to the methyl esters using tetramethylammonium hydroxide, can overcome this problem. Under the optimized measurement conditions of this study for THM-GC/MS, the average determined value (0.62 wt%) of total fatty acids in the SBR samples was found to agree well with the compounded amount (0.64 wt%) used in the preparation stage of the SBR samples, and the RSD was 3.2%.

THE TITRIMETRIC DETERMINATION OF PLASMA FATTY ACIDS

1951 ◽  
Vol 29 (5) ◽  
pp. 239-244
Author(s):  
Edouard Pagé ◽  
Loraine Michaud
Keyword(s):  
Fatty Acids ◽  
Blood Plasma ◽  
Plasma Lipids ◽  
Benzene Solution ◽  
Ammonium Hydroxide ◽  
Thymol Blue ◽  
Tetramethyl Ammonium Hydroxide ◽  
Total Fatty Acids ◽  
Titrimetric Determination

A method is described for the determination of total fatty acids in small amounts of blood plasma. The plasma lipids are extracted in an alcohol–acetone mixture. Following saponification and hydrolysis, the fatty acids from an aliquot of their benzene solution are dissolved in alcoholic thymol blue and titrated with tetramethyl ammonium hydroxide as recommended by Schmidt–Nielsen. The method is applicable to the study of alimentary hyperlipemia in rats.

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