Gas chromatographic method for determining very long chain fatty acids that compose D003 in aqueous suspensions from 20 to 200 mg/ml, used in pharmacological and toxicological studies.

D003 is a natural mixture of fatty acids (C(24:0) to C(36:0)), which shows antiplatelet, antithrombotic, and cholesterol-lowering effects in experimental models. A specific gas chromatographic method, using a BPX-5 wide-bore column and 1-nonadecanoic acid as internal standard, was developed and validated to determine the content of D003 in 20-200 mg/ml aqueous suspensions, which are used in pharmacological and toxicological studies. Fatty acids were extracted with chloroform and converted to methyl esters derivatives using 5% aqueous HCl-methanol. The method was linear for suspensions ranging from 10 to 250 mg/ml (correlation coefficient=0.9998) and showed a good accuracy, with average recoveries (98.5-101.28%) no significantly different from 100%, according to the Student t-test (P=0.05). The RSDs were <2.2%, indicating that the method has a good repeatability. The intermediate precision was good too, with RSDs between 1.20 and 2.10%. This method is suitable for quality control of these suspensions.