Apparatus for continuous extraction: Its application to the determination of unsaponifiable matter in fats and of total fatty acids in soapstock

1938 ◽  
Vol 15 (11) ◽  
pp. 287-291 ◽  
Author(s):  
I. H. Wood ◽  
H. L. Roschen
1982 ◽  
Vol 28 (4) ◽  
pp. 603-605 ◽  
Author(s):  
W Esteves ◽  
L A Soares ◽  
L Hartman ◽  
A S Pereira

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.


1972 ◽  
Vol 55 (4) ◽  
pp. 846-850
Author(s):  
F W Quackenbush

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.


2014 ◽  
Vol 87 (3) ◽  
pp. 516-525 ◽  
Author(s):  
Atsushi Watanabe ◽  
Chu Watanabe ◽  
Robert Freeman ◽  
Mari Nakajima ◽  
Norio Teramae ◽  
...  

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%.


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