INVESTIGADORES
MESSINA German Alejandro
congresos y reuniones científicas
Título:
Electrochemical monitoring of ethinylestradiol oxidation by the horseradish peroxidase enzyme in water
Autor/es:
SCALA L, ; MARTÍNEZ N, ; PEREIRA S, ; RABA J; MESSINA G. A
Lugar:
Cordoba
Reunión:
Congreso; RICIFA; 2014
Resumen:
Ethinylestradiol (EE2) is a synthetic estrogen used
in contraceptive therapy. The presence of this compound in the environment has
been attributed to their incomplete removal in wastewater treatment plant
processes.
The purpose of this research was to optimize the process
catalyzed by Horseradish peroxidase (HRP) enzyme for removal of EE2 from
synthetic water (purified deionized water) and the monitoring of the enzymatic
process by square-wave voltammetry
(SWV).
In this study, HRP catalyzes the oxidation of EE2
in presence of H2O2 and the products formed are polymerized
through a non-enzymatic process which leads to the formation of high molecular
weight polymers. These low-solubility polymers can be removed from wastewater
by co-precipitation, sorption to solids, sedimentation or filtration. The reaction mixture was prepared by diluting
stock solution of a EE2 to a concentration of 0.5 µM, in 10 mL of 0.01 M
citrate buffer pH 5.0 containing HRP 0.02 U mL-1. The reaction was initiated by adding 1 mM of H2O2.
Then, after stirring for 10 min, the sample was centrifugated and EE2 was
quantified by SWV. The
enzymatic process was monitored by SWV using a three electrodes system:
glassy carbon working electrode, Ag|AgCl|3M NaCl reference electrode and Pt counter
electrode.
For the measurement of EE2 by SWV a calibration equation was ΔI (µA)
= 1.436 + 2.382 CEE2 with a correlation coefficient of
0.998, over the concentration range of 0.3?50 µM with a
limit of detection of 0.11µM.
Our analysis demonstrated
that EE2 disappeared almost completely in the reaction mixture after 10 min
treatment. These results strongly suggest that HRP is effective in removing the
estrogenic activities of EE2 in water samples.