Simultaneous determination of ascaridole, p-cymene and α-terpinene in rat plasma after oral administration of Chenopodium ambrosioides L. by GC-MS.

A sensitive and reliable GC-MS method was developed and validated for the simultaneous determination of ascaridole, p-cymene and -terpinene in rat plasma using naphthalene as internal standard. The plasma samples were extracted with ethyl acetate. Chromatographic separation was carried out on a HP-5MS capillary analytical column (30mx0.25mm, 0.25 mu m) and detection was performed on a quadrupole mass spectrometer detector operated under selected ion monitoring mode. The method showed excellent linearity over the investigated concentration range (r>0.99) with the limit of quantitation down to 50, 10 and 5ng/mL for ascaridole, p-cymene and -terpinene, respectively. The intra-day and inter-day precisions (RSD) were <11.3%, and the accuracy was between 90.7 and 113.8%. The method was successfully applied to investigate the pharmacokinetics of Chenopodium ambrosioides L. following oral administration to rats. Copyright (c) 2015 John Wiley & Sons, Ltd.