Determination of synephrine in weight-loss products using high performance liquid chromatography with acidic potassium permanganate chemiluminescence detection

Adrenergic amines found in extracts of Citrus aurantium (bitter orange) evoke analytically useful chemiluminescence with acidic potassium permanganate in the presence of polyphosphates. From corrected chemiluminescence spectra, the wavelength of maximum intensity for these reactions was 680 +/- 5 nm and, using flow injection analysis methodology, limits of detection for synephrine, octoparnine, tyramine and hordenine were found to be between 1 x 10(-9) and 1 x 10(-8) M. We have applied this method of detection to the rapid determination of synephrine in dietary supplements using monolithic column chromatography. (c) 2007 Elsevier B.V. All rights reserved.