Liquid chromatographic determination of dehydroepiandrosterone (DHEA) in dietary supplement products

A liquid chromatographic (LC) method was developed to assess the potency of products that contain dehydroepiandrosterone (DHEA), a precursor hormone s ynthesized from cholesterol by the human adrenal cortex and converted to po tent androgens and/or estrogens in peripheral tissues, Forty-five commercia l products (both single and multi-ingredient) were subjected to analysis by the proposed method. A Zorbax R-X C-18 column with a mobile phase containi ng acetonitrile-0.025M phosphate buffer (60 + 40), pH 3.50, and UV detectio n at 292 nm was used for 87% of the products. An alternative mobile phase c ontaining methanol-0.025M phosphate (75 + 25), pH 3.50, was used to isolate DHEA from more complex product mixtures. Assay values varied from 0 to 109 .5% of the declared amount with an overall mean value of 91.1%. The recover ies based on fortified products ranged from 96.4 to 101.2%, and the intrada y precision (RSD, n = 5) varied from 0.50 to 1.66%.