Determination of amphetamine in rat brain by in vivo microdialysis and ion-pairing liquid chromatography with electrospray tandem mass spectrometry.
An ion-pairing liquid chromatography/electrospray tandem mass spectrometry (LC/ES-MS/MS) method with in vivo microdialysis for the determination of amphetamine in rat brain has been developed. A microdialysis probe was surgically implanted into the striatum of the rat and artificial cerebrospinal fluid (aCSF) was used as the perfusion medium. Samples were collected and then analyzed off-line by LC/ES-MS/MS. A reversed-phase C18 column was employed for LC separation and MS/MS was utilized for detection. Trifluoroacetic acid (TFA) was added to the mobile phase (acetonitrile/water) as an ion-pairing reagent. Detection was by ES-MS/MS directly, and no post-column addition of organic modifier was needed. Dual linear ranges were determined from 0.1-0.5 microg/mL and 0.005-0.1 microg/mL, respectively. The detection limit, based on a signal-to-noise ratio of 3, was 0.001 microg/mL (5 nM). Good precision and accuracy were obtained. The applicability of this newly developed method was demonstrated by continuous monitoring of amphetamine concentrations in rat brain. Amphetamine reached a maximum concentration of 0.086 +/- 0.017 microg/mL over 20-40 min after a single 3.0 mg/kg intraperitoneal administration.
Fuh
Ming-Ren
MR
Department of Chemistry, Soochow University, Taipei, Taiwan. msfuh@mail.scu.edu.tw
Haung
Chiuan-Hung
CH
Wu
Ti-Yu
TY
Lin
Shiang-Ling
SL
Pan
Wynn H T
WH
D000661:Amphetamine / Q000032:analysis*; D000818:Animals; D001923:Brain Chemistry; D002853:Chromatography, Liquid / Q000379:methods*; D008297:Male; D017551:Microdialysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D000661:Amphetamine