Electrochemical investigations of corticosteroid isomers—testosterone and epitestosterone and their simultaneous determination in human urine

• Published in: Analytica chimica acta Vol. 657; no. 2; pp. 147 - 153
• Main Authors: Goyal, Rajendra N., Gupta, Vinod K., Chatterjee, Sanghamitra
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 11.01.2010; Elsevier
• Subjects: Analytical chemistry; Chemistry; Chromatographic methods and physical methods associated with chromatography; Doping; Edge plane pyrolytic graphite electrode; Electrochemical methods; Electrochemical Techniques - methods; Electrodes; Epitestosterone; Epitestosterone - chemistry; Epitestosterone - urine; Exact sciences and technology; Human urine; Humans; Hydrogen-Ion Concentration; Isomerism; Limit of Detection; Nanotubes, Carbon - chemistry; Other chromatographic methods; Single-wall carbon nanotubes; Testosterone; Testosterone - chemistry; Testosterone - urine; Epitestosterone; Edge plane pyrolytic graphite electrode; Testosterone; Single-wall carbon nanotubes; Human urine; Doping; Human; Steroid; Urine; Corticosteroid; Electrochemical method; HPLC chromatography; Carbon nanotubes; Voltammetry; Isomer; Detection limit; Graphite; Simultaneous measurement; Standard curve; Square wave
• ISSN: 0003-2670; 1873-4324; 1873-4324
• DOI: 10.1016/j.aca.2009.10.035

Voltammetric investigation of two corticoid isomers—testosterone and epitestosterone has been carried out at bare and single-wall carbon nanotubes (SWNT)-modified edge plane pyrolytic graphite electrode (EPPGE). Square wave voltammetry (OSWV) has been used for the simultaneous determination of isomeric steroids. The reduction of the two isomers occurred in a pH dependent, 2e, 2H + process and well-defined voltammetric peaks were observed. Under the optimum experimental conditions, linear calibration curves are obtained within the concentration range 5–1000 nM for both the steroids with the limit of detection 2.8 × 10 −9 and 4.1 × 10 −9 M for testosterone and epitestosterone respectively. The developed protocol is successfully implemented for the analysis of both the compounds in the urine samples of normal subjects as well as in patients undergoing treatment with testosterone. The results obtained from the proposed voltammetric method were also compared with HPLC analysis and found to be similar.