Sensitive determination of ephedrine and norephedrine in human plasma samples using derivatization with 9-fluorenylmethyl chloroformate and liquid chromatography.
A high-performance liquid chromatography procedure for the determination of ephedrine and norephedrine using fluorimetric detection in plasma samples is described. A double liquid-liquid extraction was performed, followed by derivatization with 9-fluorenylmethyl chloroformate. The extracts were chromatographed with a 5-microm C18 (150x4.6 mm I.D.) column using a mobile phase composed of acetonitrile and water (52:48; v/v). The excitation and emission wavelengths were respectively 264 nm and 313 nm. Calibration curves were linear over the range 0 to 300 ng/ml for each analyte. The specificity of the method was demonstrated with several FMOC-reacting drugs. The limits of quantification are similar to those obtained with the reference method: 2 ng/ml for ephedrine and 5 ng/ml for norephedrine. This method has been successfully applied to the determination of ephedrine and norephedrine plasma levels after administration of low doses of ephedrine to healthy subjects.
Aymard
G
G
Laboratoire de Pharmacocinétique, Centre Hospitalier et Universitaire de la Pitié-Salpétrière, Paris, France.
Labarthe
B
B
Warot
D
D
Berlin
I
I
Diquet
B
B
D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004355:Drug Stability; D004809:Ephedrine / Q000097:blood*; D005449:Fluorenes / Q000737:chemistry*; D005470:Fluorometry / Q000379:methods; D006801:Humans; D010665:Phenylpropanolamine / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013566:Sympathomimetics / Q000097:blood
D005449:Fluorenes; D013566:Sympathomimetics; D010665:Phenylpropanolamine; C054007:1-(9-fluorenyl)methyl chloroformate; D004809:Ephedrine