Objective: To develop a sensitive and acurate automatic blood sampling system and HPLC-QQQ-MS method for determining the content of sinomenine and its pharmacokinetic characteristics in rat plasma. Method: SD rats were jugular vein cannula and intraperitoneal injected with 40 mg · kg-1 sinomenine after sober

blood samples were collected in rats at freely moving state by automatic blood sampling system.Codeine phosphate was used as the internal standard calibration in 20 μL sample

acetonitrile for protein precipitation.Gradient elution was performed on a Zorbax XBD-C18 column

mobile phase was consisted of 0.1% ammonium formate and acetonitrile.The analyte was detected using electrospray ionization (ESI) in multiple reaction monitoring (MRM) modes.Reaction selected ions were m/z 330.0 for sinomenine and m/z 300.0 for internal standard.Pharmacokinetic parameters were calculated by Phoenix WinNonlin software. Result: Linear ranges of sinomenine was 5.0-500.0 μg · L-1

extract recovery of this method was more than 88%

the lower limit of quantification was 1 μg · L-1

intra-day and inter-batch accuracy was 101.08%~111.08% with RSD were less than 10%.Stability was well.Main pharmacokinetic parameters of tmax

Cmax

AUC0-24 h

Vz/F

CL/F and MRT0-24 hwere (1.65±1.48) h

(210.43±96.35) μg · L-1

(1 053.80±427.69) h · μg · L-1

(252.65±57.36) L · kg-1

(30.37±11.85) L · h-1 · kg-1and (5.15±2.47) h

respectively. Conclusion: It is first time to establish a method using automatic blood sampler and HPLC-QQQ-MS to collect blood sample and determine the concentration of sinomenine in rat plasma.This method needs less sample quantity.It is so easy

acurate and sensitive for using in in vivo quantitative analysis of sinomenine.