Automated microanalysis of gabapentin in human serum by high-performance liquid chromatography with fluorometric detection.
An automated high-performance liquid chromatographic method for the determination of gabapentin, 1-(amino-methyl)cyclohexaneacetic acid, in serum is described. The procedure involves protein precipitation with methanol followed by using a robotized derivatization with o-phthaldialdehyde reagent and automated high-performance liquid chromatography. The analog of gabapentin, 1-(aminomethyl)cycloheptaneacetic acid, was used as the internal standard. Blank serum was fortified with gabapentin (0.1-10.0 microg/ml) and internal standard. Separation was achieved on a Waters 5-microm reversed-phase column (10 cmx4.6 mm) with mobile phase consisting of 0.02 M phosphate buffer (pH 4.5)-acetonitrile (50:50, v/v). Eluents were monitored by fluorescence spectroscopy with excitation and emission wavelengths of 230 and 420 nm, respectively. The calibration curve for gabapentin in serum was linear (r=0.999) over the concentration range 0.1-10.0 microg/ml. The inter- and intraassay variations for three different gabapentin concentrations were < or =10% throughout. The lower limit of quantitation was found to be 0.1 microg/ml. Chromatography was unaffected by a range of commonly employed antiepileptic drugs or selected amino acids.
Tang
P H
PH
Department of Pediatric Neurology, The Children's Hospital Medical Center, Cincinnati, OH 45229-3039, USA. Tangp0@chmcc.org
Miles
M V
MV
Glauser
T A
TA
DeGrauw
T
T
D000085:Acetates / Q000097:blood*; D000588:Amines; D000927:Anticonvulsants / Q000097:blood*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003509:Cyclohexanecarboxylic Acids; D000077206:Gabapentin; D006801:Humans; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence; D005680:gamma-Aminobutyric Acid
D000085:Acetates; D000588:Amines; D000927:Anticonvulsants; D003509:Cyclohexanecarboxylic Acids; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin