Determination of Underivatized Long Chain Fatty Acids Using HPLC with an Evaporative Light-Scattering Detector

A high-performance liquid chromatographic method with an evaporative light-scattering detector has been developed for the separation and quantitative analysis of four underivatized long chain fatty acids in four different oil matrices. An isocratic elution mode using methanol/water/acetic acid and an Agilent Eclipse XDB-C18 analytical column was used. Calibration curves of the four fatty acids (FA) were well correlated (r ² > 0.999) within the range of 1–10 mg mL⁻¹ for linoleic acid, 0.8–10 mg mL⁻¹ for stearic acid and 0.5–10 mg mL⁻¹ for the other FA. Four oil samples were examined; camellia oil, olive oil, Brucea javanica oil and sesame oil. Good agreement was found with the standard gas chromatographic (GC) method. The proposed method offers distinct advantages over the official GC method; better separation and precision, and the sample components do not need to be derivatized.