Determination of dehydroepiandrosterone in dietary supplements by reversed-phase HPLC

Purpose: To develop a reversed phase high performance liquid chromatography (HPLC) method for the determination of dehydroepiandrosterone (DHEA) in dietary supplements. Methods: A reversed-phase high performance liquid chromatography (HPLC) method was developed for the determination of DHEA in dietary supplements. An isocratic system consisting of methanol and water (70:30 v/v) was run at a flow rate of 1 mL/min on a C18 HPLC column to achieve the separation. The method was validated with regard to linearity, intra-day and inter-day precision, and limits of both detection and quantification. Results: The method achieved a retention time of 10.8 min, a resolution of 4.12, a detection limit (LOD) of 50 ng/μL, a quantification limit (LOQ) of 166.7 ng/μL and a label claim of 108.6 % with a relative standard deviation (RSD) of 0.38 % over a range of 0.0625 – 0.50 mg/mL with a correlation coefficient of 0.9997. Conclusion: The method is simple, cost effective, time-saving and reliable for determining DHEA when compared to other reported methods in literature. Thus, it will be of benefit to manufacturers of this dietary supplement to adopt the method for quantitative laboratory analysis