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Electroanalytical Determination of Estrone in Seawater Samples Using Functionalized Multiwalled Carbon Nanotubes
Author(s) -
Okina Renato Hisashi,
Valle Eliana Maíra Agostini,
Simões Fabio Ruiz,
Codognoto Lucia
Publication year - 2021
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.202060469
Subject(s) - seawater , calibration curve , adsorption , carbon nanotube , cyclic voltammetry , chemistry , voltammetry , electrode , analytical chemistry (journal) , glassy carbon , detection limit , nuclear chemistry , materials science , chromatography , electrochemistry , organic chemistry , nanotechnology , geology , oceanography
In this work, a glassy carbon electrode (GCE) modified with multiwalled carbon nanotubes functionalized with carboxylic groups (MWCNT−COOH) was used to determine the hormone estrone in seawater samples. Modification of the electrode was optimized using three successive 10‐μL aliquots of the MWCNT−COOH dispersion in ethanol (1 : 5 mL). The cyclic voltammetry results showed an oxidation peak at 0.59 V with characteristics of an irreversible process, pH dependent and controlled by adsorption of species. The results of square‐wave voltammetry showed that the intensities of peak currents for the MWCNT−COOH/GCE were about 2.5 times higher than for GCE. The calibration curve showed a linearity of 0.9981 and a sensitivity of 0.1521 μA/mol L −1 . The limits of detection and quantification were 0.117 and 0.392 μmol L −1 , respectively. The recovery obtained using seawater samples was 91%, indicating the applicability of the method in marine environments.