Comparison of methods for analysis of resveratrol in dietary vegetable supplements.

Resveratrol is a stilbene, which is one of a group of polyphenols in many plant foods. Interest in this substance lies in its potential health benefits. This study aimed to compare two different methods, chromatographic and constant-wavelength synchronous spectrofluorimetry, an alternative technique to determine the amount of resveratrol dietary supplements, as a model for more complex foods. High-performance liquid chromatography-photodyode array detector-mass spectrometry/mass spectrometry was used to confirm the results. The results obtained showed that both methods were valid for the determination of resveratrol in dietary supplements. HPLC with fluorescence and variable wavelength detectors offered better linearity and sensitivity, and would be more suitable for the determination of several stilbenes in complex samples. On the other hand, constant-wavelength synchronous spectrofluorimetry is a sensitive, rapid and inexpensive method that could be used for quick and precise determination when samples are expected to contain only one stilbene.