title: Determination of strychnine and brucine in rat plasma using liquid chromatography electrospray ionization mass spectrometry.
abstract: A simple, sensitive and selective liquid chromatography-electrospray mass spectrometric (LC-ESI-MS) method was developed and validated for simultaneous determination of strychnine and brucine in rat plasma, using tacrine as the internal standard (IS). Sample preparation involved a liquid-liquid extraction of the analytes with n-hexane, dichloromethane and isopropanol (65:30:5, v/v/v) from 0.1mL of plasma. Chromatographic separation was carried out on a Waters C(18) column using a mobile phase of methanol-20mM ammonium formate-formic acid (32:68:0.68, v/v/v). Positive selected ion monitoring mode was used for detection of strychnine, brucine and the IS at m/z 335.2, m/z 395.2 and m/z 199.2, respectively. Linearity was obtained over the concentration range of 0.5-500ng/mL for strychnine and 0.1-100ng/mL for brucine. The lower limit of quantification was 0.5ng/mL and 0.1ng/mL for strychnine and brucine, respectively. The intra- and inter-day precision for both strychnine and brucine was less than 7.74%, and accuracy ranged from -4.38% to 2.21% at all QC levels. The method has been successfully applied to a pharmacokinetic study of processed Semen Strychni after oral administration to rats.
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Xu
authors.forename: Duanyun
authors.initials: D
authors.lastname: Si
authors.forename: Changxiao
authors.initials: C
authors.lastname: Liu
mesh_terms: D019840:2-Propanol / Q000737:chemistry; D000818:Animals; D002138:Calibration; D002853:Chromatography, Liquid / Q000295:instrumentation / Q000379:methods; D004305:Dose-Response Relationship, Drug; D005561:Formates / Q000737:chemistry; D006586:Hexanes / Q000737:chemistry; D008297:Male; D000432:Methanol / Q000737:chemistry; D008752:Methylene Chloride / Q000737:chemistry; D015394:Molecular Structure; D011786:Quality Control; D051381:Rats; D017208:Rats, Wistar; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013331:Strychnine / Q000031:analogs & derivatives* / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D013997:Time Factors
chemical_list: D005561:Formates; D006586:Hexanes; C030544:formic acid; C026385:n-hexane; D008752:Methylene Chloride; D013331:Strychnine; D019840:2-Propanol; D000432:Methanol