Colorimetric determination of free fatty acids in biological fluids

Colorimetric Determination of Free Fatty Acids in Biological Fluids.

Following the introduction by Duncombe of a colorimetric micromethod for the determination of free fatty acids (FFA) dissolved in chloroform, we studied the optimum conditions for chloroform extraction of FFA from blood or other biological fluids. A degree and rate of extraction similar to those with Dole’s extraction mixture were obtained. Phospholipids are not extracted by the procedure descr...

Automated colorimetric determination of free fatty acids in biologic fluids.

HE MOST FREQUENTLY USED procedure for the determination of free fatty acids (FFA) in body fluids or biologic media is that of Dole (4). This method is based on the extraction of fatty acids with organic solvents followed by titration with dilute alkali. Despite improvements in specificity (3, 5, 6), this method is subject to error resulting from dissolved atmospheric carbon dioxide. When applie...

Colorimetric Ultramicro Method for the Determination of Free Fatty Acids.

Rapid colorimetric micromethod for free fatty acids.

Free fatty acids (FFA), the uranyl ion, and the basic dye Rhodamine B form colored complexes, which are extractable into toluene or benzene. Fatty acids of different chain lengths above C(10) and different degrees of unsaturation gave constant molar yield. Complexes in toluene alone are unstable, especially in the light, but a small amount of aqueous uranyl acetate stabilizes them sufficiently ...

A more sensitive and stable colorimetric determination of free fatty acids in blood.

A sensitive method is proposed for the colorimetric determination of free fatty acids (FFA). Diphenylcarbazide containing diphenylcarbazone is used as the color developing reagent instead of diethyldithiocarbamate which was employed in the previous method (1965). J. Lipid Res. 6: 16-20). The present method was successfully applied to the determination of FFA present in as little as 40 microlite...