Submitted to: Journal of Association of Official Analytical Chemists International
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/1/2013
Publication Date: 7/1/2015
Citation: Chen, P., Bryden, N.A. 2015. Single laboratory validation of the determination of yohimbine in yohimbe bark and related dietary supplements using UHPLC/UV/MS. Journal of Association of Official Analytical Chemists International. 98:896-901.
Interpretive Summary: Yohimbine is an active indole alkaloid with stimulant and aphrodisiac effects found naturally in Pausinystalia yohimbe (yohimbe). It has been used as a prescription medicine for the treatment of erectile dysfunction in the United States in its hydrochloride form. Commercial dietary supplements of yohimbe bark are also widely available as over-the-counter dietary supplements for the treatment of sexual dysfunction and enhancement of sexual satisfaction. An ultra high-performance liquid chromatographic (UHPLC) method was developed for the determination of yohimbine in the yohimbe bark and related dietary supplements. The method developed was successfully applied to the determination of yohimbine in 12 commercial commercial yohimbe dietary supplements samples. Wide variability was observed in the yohimbine contents among yohimbe dietary supplement samples. For most of the dietary supplements, contents of their yohimbine measured were not consistent with their label claims.
Technical Abstract: A single laboratory validation has been performed on a practical ultra high-performance liquid chromatography (UHPLC), diode array detection (DAD), and tandem mass spectrometry (MS) method for determination of yohimbine in yohimbe barks and related dietary supplements. Good separation was achieved using a Waters Acquity BEH C18 column with gradient elution using 0.1% (v/v) aqueous ammonium hydroxide and 0.1% ammonium hydroxide in methanol as the mobile phases. The method can separate corynanthine from yohimbine in yohimbe bark extract, which is critical for accurate quantitation of yohimbine in yohimbe bark and related dietary supplements. Accuracy of the method was demonstrated using standard addition methods. Both intra-day and inter-day precisions of the method have been good. The method can be used without MS since yohimibine concentration in yohimbe barks and related dietary supplements are usually high enough for DAD detection, which can make it an easy and economical method for routine analysis of yohimbe barks and related dietary supplements. On the other hand, the method can be used with a MS if desired for more challenging works such as biological and/or clinical studies.