Determination of seven fatty acids in plasma of rats after oral administration of Xanthoceras sorbifolia bunge oil by GC-MS and pharmacokinetic study

This work aims to establish a highly selective, sensitive, and accurate gas chromatography-mass spectrometry (GC-MS) method for detecting concentrations of seven representative fatty acids absorbed into the bloodstream after a single gavage of 10 mL/kg Xanthoceras sorbifolia Bunge (X.sorbifolia) oil in rats and conducting pharmacokinetic studies. The plasma samples were processed using two-step derivatization with NaOH and BF₃-CH₃OH, with an Agilent HP-88 capillary column serving as the stationary phase. Concentrations of seven fatty acids, namely hexadecanoic acid (palmitic acid, C16:0), octadecenoic acid (stearic acid, C18:0), cis-9-octadecenoic acid (oleic acid, C18:1), cis-9,12-octadecadienoic acid ( linoleic acid, C18:2), cis-11-eicosenoic acid (gondoic acid, C20:1), cis-13-docosaenoic acid (erucic acid, C22:1), and cis-15-tetracosenoic acid (nervonic acid, C24:1), were quantitatively determined under programmed temperature and ion detection mode. The results showed that the seven fatty acids were well separated and exhibited a good linear relationship between concentration and peak area ratio within the detection range (R² > 0.99). The precision and accuracy within and between batches were both less than 15%. After derivatization, the plasma samples remained stable at -20 °C, 4 °C, and 10 °C; The matrix effect did not affect the quantitative analysis, and the extraction recovery rate ranged from 100.3% to 107.76%. After gavage administration of X.sorbifolia oil to rats, the levels of unsaturated fatty acids in the blood were significantly increased compared to those in the blank control group. The peak concentration (T max) was 7–8 h, and the mean retention time (MRT) was 10–12 h. This experiment provides a basis for elucidating the potential material basis of the nutritional efficacy of X. sorbifolia oil after oral administration.