Quantitation of cocaine and cocaethylene in canine serum by high-performance liquid chromatography.
A reversed-phase high-performance liquid chromatographic procedure for the determination of cocaine and cocaethylene in canine serum has been developed. The compounds were extracted from 1 ml of alkalinized canine serum with hexane. Chromatographic separation was achieved with a cyanopropyl column (250 x 4.6 mm I.D., 5 microns) using a mobile phase of acetonitrile and phosphate buffer, pH 7.40 (38:62, v/v) flowing at 1 ml/min. Eluate was monitored by a variable-wavelength UV detector set to 230 nm. The extraction procedure yields an average recovery of 99 and 96% for cocaine and cocaethylene, respectively. The between-day coefficients of variation, at 2400 ng/ml, for cocaine and cocaethylene were both 8.6% and the within-day coefficients of variation, at 400 ng/ml, for cocaine and cocaethylene were 7.3 and 8.0%, respectively. A concentration-time profile resulting from administration of 3 mg/kg cocaine and cocaethylene to the dog revealed a similar disposition between cocaine and cocaethylene, with a clearance and volume of distribution at steady-state values of 72.8 and 61.0 ml/min/kg and 2.6 and 2.7 1/kg, respectively.
Williams
C L
CL
University of Tennessee, Department of Clinical Pharmacy, Memphis 38163, USA.
Laizure
S C
SC
Parker
R B
RB
Lima
J J
JJ
D000097:Acetonitriles; D000818:Animals; D002021:Buffers; D002851:Chromatography, High Pressure Liquid / Q000379:methods* / Q000706:statistics & numerical data; D003042:Cocaine / Q000031:analogs & derivatives* / Q000097:blood* / Q000493:pharmacokinetics; D004285:Dogs; D006863:Hydrogen-Ion Concentration; D010710:Phosphates
D000097:Acetonitriles; D002021:Buffers; D010710:Phosphates; C066444:cocaethylene; D003042:Cocaine; C032159:acetonitrile