Determination of arbidol in human plasma by LC–ESI-MS

A sensitive, specific and accurate method for determination of arbidol in human plasma was developed. Arbidol and internal standard were extracted from plasma samples by liquid–liquid extraction with diethyl ether. The chromatographic separation was accomplished on a Shiseido C18 3 μm analytical column (100 mm × 2.0 mm i.d.) at a flow rate of 0.3 mL/min isocratically. Detection was performed on a single quadrupole mass spectrometer by selected ion monitoring (SIM) mode via electrospray ionization (ESI) source. The method had a chromatographic run time of 6 min and a good linear relationship over the range 1–1000 ng/mL. The limit of quantitation for arbidol in plasma was 1 ng/mL. The intra-day and inter-day precision (R.S.D.%) was lower than 7% and accuracy ranged from 95 to 105%. The proposed method enables unambiguous identification and quantification of arbidol in vivo and has been successfully applied to study the pharmacokinetics of arbidol in healthy male Chinese volunteers.