Voltammetric determination of 17 alpha-ethinylestradiol hormone in supply dam using BDD electrode

Abstract

In this work, a simple method for electroanalytical determination of 17 alpha-ethinylestradiol (EE2) hormone in natural waters was developed using a boron-doped diamond electrode (BDD). The analyses were performed using square wave voltammetry and the parameters were optimized. The results showed a well-defined irreversible oxidation peak (BR buffer 0.1 mol L-1, pH 8.0) at +0.65 V (vs. Ag/AgCl). The voltammetric results showed also that the oxidation process is controlled by adsorption of species and indicated that there are two electrons involved. The obtained analytical curves for 17 alpha-ethinylestradiol presented good linearity in the concentration range 9.9 x 10(-7) to 5.2 x 10(-6) mol L-1 in utlrapure water and 7.9 x 10(-7) to 5.2 x 10(-6) mol L-1 in natural water samples (supply dam). Detection limits (DL) obtained were between 2.4 x 10(-7) and 7.5 x 10(-7) mol L-1 and quantification limits (QL) between 7.9 x 10(-7) and 2.5 x 10(-6) mol L-1. The recovery experiments showed values between 86 and 114 % for spiked samples thus indicating the applicability of the electroanalytical methodology to quantify 17 alpha-ethinylestradiol directly in natural water of supply Dam (Billings Dam in Diadema-SP. Brazil), without any preconcentration or derivatization.