ABSTRACT
A new method based on ultraperformance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) was developed for the simultaneous determination of 22 endocannabinoids(eCBs) and relevant compounds in ovariectomized rat plasma. After being extracted by solid-phase column(SPE), the plasma samples were detected by using UPLC-MS/MS. Analysis was carried out with ACQUITY UPLC BEH C₁₈ column. The mobile phase was 0.1% acetic acid solution(A)-acetonitrile and isopropanol(9∶1, B) for the gradient elution. In the positive ion multiple reaction monitoring(MRM) mode, deuterated reagents were taken as standard alternatives to calculate recoveries and simultaneously quantify 22 endocannabinoids. The established method provided a good linearity for the 22 eCBs, and their linearly dependent coefficients were all higher than 0.99. The limits of quantitation(LOQs) ranged from 0.089 6 to 1.965 2 nmol•L-1. Relative recoveries of 5 deuterated surrogates ranged between 11.40% and 129.9%. The repeatability study results showed that RSD was all less than 8.0%. The established method could be used to analyze PGF2a EA, AEA and other endogenous cannabinoids in plasma samples of ovariectomized rats. In summary, this method was proved to boast a high sensitivity, repeatability and practicability, and thus could be used in rat plasma lipid metabolomics study.