Electrochemical detection of a powerful estrogenic endocrine disruptor: ethinylestradiol in water samples through bioseparation procedure

NOELIA A. MARTÍNEZ; SIRLEY V. PEREIRA; FRANCO A. BERTOLINO; RUDOLF J. SCHNEIDER; GERMÁN A. MESSINA; JULIO RABA

ANALYTICA CHIMICA ACTA

ELSEVIER SCIENCE BV

Año: 2012 vol. 723 p. 27 - 32

0003-2670

The  synthetic  estrogen  ethinylestradiol  (EE2)  is  an  active  component  of  oral contraceptives  (OCs),  considered  as  an  endocrine  disrupting  compound  (EDC).  It  is excreted  from humans  and  released  via  sewage  treatment  plant  effluents  into  aquatic environments. EDCs are any environmental pollutant chemical that, once incorporated into an  organism,  affects  the  hormonal  balance  of  various  species  including  humans.  Its presence  in  the environment  is becoming of great  importance  in water quality. This paper describes  the  development  of  an  accurate,  sensitive  and  selective  method  for  capture, preconcentration  and  determination  of  EE2  present  in  water  samples  using:  magnetic particles  (MPs)  as  bioaffinity  support  for  the  capture  and  preconcentration  of EE2  and  a glassy carbon electrode modified with multi-walled carbon nanotubes (MWCNTs/GCE) as detection system. The capture procedure was based on the principle of immunoaffinity, the EE2 being extracted  from  the  sample using  the anti-EE2 antibodies  (anti-EE2 Ab) which were  previously  immobilized  on  MPs.  Subsequently  the  analyte  desorption  was  done employing a sulfuric acid solution and the determination of the EE2 in the pre-concentrated solution was carried out by square wave voltammetry (SWV). This method can be used  to determine EE2  in  the range of 0.035–70 ng L-1 with a detection  limit (LOD) of 0.01 ng L-1 and R.S.D. < 4.20%. The proposed method has been successfully  applied  to  the  determination  of  EE2  in water  samples  and  it  has  promising analytical applications for the direct determination of EE2 at trace levels.