VOLTAMMETRIC DETERMINATION OF ESTRADIOL IN MILK AND PHARMACEUTICALS BASED ON FUMED-SILICA MODIFIED CARBON PASTE ELECTRODE

In this study, modification of carbon paste electrode (CPE) with a nano-structured substance, fumed silica (FS), was investigated to develop a voltammetric method for the determination of an endocrine disrupting chemical, estradiol (EST). FS prominently increased the voltammetric response of CPE towards EST. The parameters that affect the volmametric performance of modified CPE were examined to find the optimal conditions. Modified electrode showed a linear response towards EST between the concentration values of 0.1 mM and 15.0 mM EST. Limit of detection value for the method developed was calculated as 0.023 mM. Production reproducibility of the modified electrode was obtained as 3.6 %. The voltammetric behavior of EST was also examined in the presence of different possible substances to evaluate their interference effects. The modified electrode successfully discriminated the oxidation potential of EST in the presence of different substances. The determination of EST was tested in milk and pharmaceutical samples to evaluate the analytical performance of the method. The recovery analysis of EST in milk samples showed that the modified electrode can be used safely in these samples. The modified electrode also achieved the determination of EST in pharmaceutical samples.