Assay of Yohimbine in Human Plasma Using High Performance Liquid Chromatography with Electrochemical Detection

Abstract

Yohimbine is a selective .alpha.2 adrenoreceptor antagonist used in the study of .alpha.2 adrenoreceptors in man. In order to better improve administration regimens for the study of yohimbine in man, an assay was developed for the determination of yohimbine in plasma utilizing reverse phase high performance liquid chromatography with electrochemical detection. Using a C18 column and a methanol:acetate (60:40) mobile phase, yohimbine was detected in plasma following a simple chloroform extraction. Reserpiline was used as an internal standard. The assay was linear over a concentration range of 50-250 ng/ml in spiked plasma and had a lower limit of sensitivity of 10 ng/ml. It was used to detect yohimbine in plasma sampled from 4 volunteers during an infusion of the alkaloid.