ABSTRACT
A sensitive and accurate liquid chromatography-tandem mass spectrometry method was developed and validated for the determination of dryocrassin ABBA, a potential active component isolated from Dryopteris crassirhizoma, in rat plasma. Chromatographic separation was achieved on a Zorbax SB-C18 column (50 × 2.1 mm, 1.8 µm), with elution consisting of eluent (A) 10 mm ammonium acetate in methanol containing 0.1% formic acid and (B) 10 mm ammonium acetate in water containing 0.1% formic acid (A:B = 99:1, v/v) at a flow rate of 0.3 mL/min. Multiple reaction monitoring mode was used to monitor the precursor-product ion transitions of m/z 819.3 â 403.4 for dryocrassin ABBA and m/z 426.2 â 409.2 for internal standard. This assay exhibited a good linearity with a correlation coefficient >0.99 and showed no endogenous interference with the analyte and internal standard. The lower limit of quantification of dryocrassin ABBA was 4 ng/mL in 50 µL of rat plasma. The method was successfully applied in the pharmacokinetic study of dryocrassin ABBA in rats after intravenous (2.35 mg/kg) and oral (23.5 mg/kg) doses of dryocrassin ABBA. The oral bioavailability (F) of dryocrassin ABBA was estimated to be 50.1%. Our study is the first to clarify the pharmacokinetic behaviors of dryocrassin ABBA in animals.
Subject(s)
Benzylidene Compounds/blood , Benzylidene Compounds/pharmacokinetics , Chromatography, Liquid/methods , Cyclohexanones/blood , Cyclohexanones/pharmacokinetics , Tandem Mass Spectrometry/methods , Acetates , Animals , Benzylidene Compounds/chemistry , Biological Availability , Cyclohexanones/chemistry , Drug Stability , Linear Models , Male , Rats , Rats, Wistar , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
To non-dispersive infrared gas analysis, it was the most difficult challenge to maintain very low zero and temperature drift over long periods. Electronic and detector response drifts irremediably required some form of manual zeroing procedure. To solve zero and temperature drift, a multi-parameters model was developed, by which zero and temperature drifts were automatically corrected. These parameters include zero gas intensity, reference channels intensity, standard temperature, environment temperature, temperature drift coefficients etc. Trial results and in-situ applications showed that the monitoring precisions of the instrument were lesser than 5% F. S in different temperatures and for a long time. The average precision of monitoring carbon monoxide concentration increased respectively from 9.26 to 1.23%, and monitoring hydrocarbon concentration from 10.61% to 0.70% before and after compensated. The instrument required essentially no periodic calibration and have very low maintenance cost.