Objective :To establish a measurement method for determining the levels of monoamines neurotransmitter and their metabolites in rat plasma by HPLC with Coularray Detector-2. Methods :The levels of NE

E

DA

HVA and 5-HT in rat plasma were determined by Agilent 1200 HPLC with ESA Coularray Detector-2. Mobile phase consisted of 80 mmol·L-1 Citric acid monohydrate

73.4 mmol·L-1 Citric acid trisodium salt

0.12 mmol·L-1 1-Octanesulfonic acid sodium salt

0.1 mmol·L-1 EDTA-Na2 and 18% methanol mixture solution(pH4.3). Flow rate was 1.0 mL·min-1.The Column was Zorbax Eclipse XDB-C18 (4.6 mm×150 mm

5 μm)and Easyguard guard column at 25 ℃. The voltage of electrode was -150 mv and 400 mv. Results :The minimum measurement limit of NE

E

DA

HVA and 5-HT were 2.0

3.0

5.4

5.2 and 11.1 ng·mL-1 respectively. The average recoveries were 99.72％

85.33％

83.15％

120.43％ and 103.56％

respectively. The RSD of intra-day (n=6) and inter-day (n=3) were less than 9.12%. Conclusion :The method was easy to operate

rapid

accuracy and high in sensitivity

and could be applied in quantitative determination and study of monoamines neurotransmitters and their metabolites in rat plasma.