FAST DETERMINATION OF 17β-ESTRADIOL USING A 3D-PRINTED BASED ELECTRODE COUPLED TO A NOVEL BATCH INJECTION ANALYSIS CELL

17β-estradiol (E2) is the main female sex hormone widely used in pharmaceutical formulations indicated for contraception and replacement therapy. Because this hormone is secreted by the body and contaminates the aquatic environment, it is considered an important organic pollutant to monitor due to its action on the human body as an endocrine disruptor [1]. Therefore, the development of rapid, sensitive, precise, and portable methods is relevant for its quantification in different matrices. This work proposes the determination of E2 using a 3D-printed based sensor (composite of Graphite-Acrylonitrile Butadiene Styrene / G- ABS coated on a 3D-printed ABS substrate) [2] assembled in a novel user-friendly 3D-printed batch injection analysis cell with amperometric detection (BIA-AD). Firstly, cyclic voltametric studies were performed in Britton-Robinson buffer 0.04 mol L^-1 (pH 3), being obtained an irreversible anodic peak around + 0.85 V. Under the optimized conditions of BIA-AD (E = +1.1 V, injection volume = 100 µL, dispensing rate = 142 µL s^-1), a sensitivity of 0.356 µA µmol^-1 L, a linear range of 0.029 to 6.0 µmol L^-1, a real LOD of 0.1 µmol L^-1 and an analytical frequency of 170 h^‑1 were obtained. Moreover, good manufacture efficiency was reached (RSD = 5.5 %; n = 4). The method was applied in a pharmaceutical sample (labeled as 1 mg of estradiol per pill) and a river water. The obtained result in the pharmaceutical sample was similar to the value found by a UV-VIS spectrophotometric method. The value found in river water was below the limit of detection. Thus, this sample was fortified with 0.5, 3.0, and 5.0 µmol L^-1, being obtained recoveries of 107, 124, and 138%, respectively. These results confirm the good accuracy of the proposed BIA-AD for the determination of E2 in different matrices.