کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1224350 | 967920 | 2007 | 7 صفحه PDF | دانلود رایگان |
The electrochemical behavior of norethisterone at the mercury electrode was studied in the universal buffer of various pH values using dc-polarography, cyclic voltammetry and controlled-potential electrolysis. Norethisterone was reduced at the mercury electrode via the consumption of two electrons corresponding to reduction of the 3-keto-delta-4-group in the A-ring of the molecule. The pKa value (8.7) of norethisterone was determined from the polarographic and spectrophotometric measurements. A fully validated, simple, sensitive, precise and inexpensive square-wave adsorptive cathodic stripping (SWAdCS) voltammetry procedure was described for trace quantification of bulk norethisterone. The stripping voltammetry peak current of norethisterone in a universal buffer of pH 5 following its accumulation onto the hanging mercury drop electrode (HMDE) at −0.6 V (versus Ag/AgCl/KCls) for 130 s showed a linear response with the concentration over the range 5 × 10−9 to 3 × 10−7 M norethisterone. Detection and quantitation limits of 1.5 × 10−9 and 5 × 10−9 M bulk norethisterone, respectively, were achieved. The proposed procedure was successfully applied for the assay of norethisterone in Steronate tablets without interference from excipients.
Journal: Journal of Pharmaceutical and Biomedical Analysis - Volume 43, Issue 2, 17 January 2007, Pages 499–505