Enantiomeric analysis of phenylpropanolamine in plasma via resolution of dinitrophenylurea derivatives on a high performance liquid chromatographic chiral stationary phase.
Racemic phenylpropanolamine was resolved on a high performance liquid chromatographic (HPLC) chiral stationary phase (CSP) as the 3,5-dinitrophenyl ureide derivative. The CSP was prepared by a simple in situ procedure in which (R)-(1-naphthyl)ethyl isocyanate was bound to aminopropyl silanized silica through a urea linkage. The enantiomeric ureides were prepared by a room-temperature, 60-second procedure, accomplishing simultaneous extraction and derivatization and utilizing achiral 3,5-dinitrophenyl isocyanate as reagent. Baseline resolution was readily achieved under normal phase conditions, with a separation factor (alpha) of 1.16 and a resolution factor (RS) of 2.2. Elution was complete within 10 min. A limit of detection, by UV at 235 nm, of 250 pg per isomer was established. Feasibility of the procedure for plasma determinations was demonstrated by assay of samples from a canine subject.
Doyle
T D
TD
Food and Drug Administration, Division of Research and Testing, Washington, DC 20204.
Brunner
C A
CA
Vick
J A
JA
D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003485:Cyanates; D004136:Dinitrobenzenes; D004285:Dogs; D007202:Indicators and Reagents; D017953:Isocyanates; D009281:Naphthalenes; D010665:Phenylpropanolamine / Q000097:blood*; D012822:Silicon Dioxide; D013237:Stereoisomerism
D003485:Cyanates; D004136:Dinitrobenzenes; D007202:Indicators and Reagents; D017953:Isocyanates; D009281:Naphthalenes; D010665:Phenylpropanolamine; C054308:1-(1-naphthyl)ethyl isocyanate; C068908:3,5-dinitrophenyl isocyanate; D012822:Silicon Dioxide