High-Performance Thin-Layer Chromatographic Quantification of Yohimbine in the Stem Bark of Pausinystalia yohimbe

A simple, sensitive, and reliable normal-phase HPTLC method has been established for quantification of yohimbine in the stem bark of P yohimbe. A methanol extract of powdered stem bark was used for quantification. Chromatography was performed on silica gel F(254) HPTLC plates with toluene-ethyl acetate-diethyl amine 7:2:1 (v/v) as mobile phase. Quantification was achieved by densitometric scanning at 285 nm in reflectance-absorbance mode. The response to yohimbine was a linear function of concentration over the range 400 to 1200 ng per band. The mean amount of yohimbine in samples of the stem bark of P yohimbe was 0.56 mg g(-1). The method was validated for selectivity, linearity, accuracy, recovery, precision, and robustness.