title: Rapid Screening Method for Detecting Ethinyl Estradiol in Natural Water Employing Voltammetry.
abstract: 17α-Ethinyl estradiol (EE2), which is used worldwide in the treatment of some cancers and as a contraceptive, is often found in aquatic systems and is considered a pharmaceutically active compound (PhACs) in the environment. Current methods for the determination of this compound, such as chromatography, are expensive and lengthy and require large amounts of toxic organic solvents. In this work, a voltammetric procedure is developed and validated as a screening tool for detecting EE2 in water samples without prior extraction, clean-up, or derivatization steps. Application of the method we elaborate here to EE2 analysis is unprecedented. EE2 detection was carried out using differential pulse adsorptive cathodic stripping voltammetry (DP AdCSV) with a hanging mercury drop electrode (HMDE) in pH 7.0 Britton-Robinson buffer. The electrochemical process of EE2 reduction was investigated by cyclic voltammetry at different scan rates. Electroreduction of the hormone on a mercury electrode exhibited a peak at -1.16 ± 0.02 V versus Ag/AgCl. The experimental parameters were as follows: -0.7 V accumulation potential, 150 s accumulation time, and 60 mV s-1scan rate. The limit of detection was 0.49μg L-1for a preconcentration time of 150 s. Relative standard deviations were less than 13%. The method was applied to the detection of EE2 in water samples with recoveries ranging from 93.7 to 102.5%.
authors.affiliation: Departamento de Química, Universidade Estadual do Centro-Oeste, 85040-080 Guarapuava, PR, Brazil.
authors.forename: Chalder Nogueira
authors.identifier: 0000-0001-6373-4739
authors.initials: CN
authors.lastname: Nunes
authors.affiliation: Departamento de Química, Universidade Estadual do Centro-Oeste, 85040-080 Guarapuava, PR, Brazil.
authors.forename: Lucas Ely
authors.identifier: 0000-0002-0969-6097
authors.initials: LE
authors.lastname: Pauluk
authors.affiliation: Departamento de Química, Universidade Estadual do Centro-Oeste, 85040-080 Guarapuava, PR, Brazil.
authors.forename: Maria Lurdes
authors.identifier: 0000-0002-7938-8399
authors.initials: ML
authors.lastname: Felsner
authors.affiliation: Departamento de Química, Universidade Estadual de Ponta Grossa, 84030-900 Ponta Grossa, PR, Brazil.
authors.forename: Vanessa
authors.identifier: 0000-0002-6235-3755
authors.initials: V
authors.lastname: Egéa Dos Anjos
authors.affiliation: Departamento de Química, Universidade Estadual do Centro-Oeste, 85040-080 Guarapuava, PR, Brazil.
authors.forename: Sueli Pércio
authors.identifier: 0000-0002-1485-1063
authors.initials: SP
authors.lastname: Quináia