Simultaneous Quantification of Multiple Analytes in Rat Plasma by UHPLC–MS/MS Following Oral Administration of Gastrodiae Rhizoma Extract for Pharmacokinetic Evaluation

<i>Gastrodiae Rhizoma</i> (GR) is known to have a medicinal and food-based homology. It is used to treat infantile convulsion, epilepsy, spasm, tetanus, and vertigo. In this study, an ultra-high performance liquid chromatography/tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated to quantify fourteen components (<i>p</i>-hydroxybenzyl alcohol, gastrodin, parishin E, <i>p</i>-hydroxybenzoic acid, parishin C, parishin A, parishin B, nicotinamide, <i>p</i>-hydroxybenzaldehyde, adenosine, 3,4-dihydroxybenzaldehyde, syringaldehyde, dauricine, and nobiletin) of GR in rat plasma. Methanol precipitation was used to prepare the samples with astragalin, serving as the internal standard. In multiple reaction monitoring (MRM) mode, the fourteen components were separated by gradient elution on a Waters ACQUITY UPLC^® HSS T3 column. Under these conditions, all fourteen analytes' calibration curves demonstrated strong linearity within wide concentration ranges (r > 0.9941). Accuracy for the intra-day and inter-day assessments ranged from -13.74% to 12.76%, and the precision for all analytes remained below 8.88%. The analytes' extraction recoveries ranged from 66.78% to 114.2%, accompanied by matrix effects ranging from 63.65% to 117.61%. Under the evaluated conditions, stability tests confirmed that the compounds remained stable, with relative standard deviations below 13.83%. Consequently, the UHPLC-MS/MS method was effectively used to determine the pharmacokinetics of fourteen components in rat plasma after oral administration of GR extract. This study provides supportive data for rational application of GR.