Determination of estrogenic endocrine disruptor: Ethinylestradiol, using modified magnetic nanoparticles

NOELIA A. MARTÍNEZ; MARTÍN FERNÁNDEZ BALDO; FRANCO A. BERTOLINO; MARÍA I. SANZ; GERMÁN A. MESSINA; JULIO RABA

Córdoba

Congreso; 1º Reunión Internacional de Ciencias Farmacéuticas; 2010

RICiFa, Universidad Nacional de Córdoba

<!-- /* Font Definitions */ @font-face {font-family:MTSY; panose-1:0 0 0 0 0 0 0 0 0 0; mso-font-alt:"Arial Unicode MS"; mso-font-charset:129; mso-generic-font-family:auto; mso-font-format:other; mso-font-pitch:auto; mso-font-signature:3 151388160 16 0 524289 0;} @font-face {font-family:Calibri; panose-1:0 0 0 0 0 0 0 0 0 0; mso-font-alt:"Century Gothic"; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-format:other; mso-font-pitch:variable; mso-font-signature:3 0 0 0 1 0;} @font-face {font-family:AdvTT5843c571; panose-1:0 0 0 0 0 0 0 0 0 0; mso-font-charset:0; mso-generic-font-family:roman; mso-font-format:other; mso-font-pitch:auto; mso-font-signature:3 0 0 0 1 0;} @font-face {font-family:"@MTSY"; panose-1:0 0 0 0 0 0 0 0 0 0; mso-font-charset:129; mso-generic-font-family:auto; mso-font-format:other; mso-font-pitch:auto; mso-font-signature:1 151388160 16 0 524288 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin-top:0cm; margin-right:0cm; margin-bottom:10.0pt; margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:Calibri; mso-fareast-font-family:Calibri; mso-bidi-font-family:Calibri; mso-ansi-language:ES-AR; mso-fareast-language:EN-US;} span.MsoFootnoteReference {mso-style-noshow:yes; vertical-align:super;} span.apple-style-span {mso-style-name:apple-style-span;} /* Page Definitions */ @page {mso-footnote-separator:url("file:///C:/DOCUME~1/Martin/CONFIG~1/Temp/msohtml1/01/clip_header.htm") fs; mso-footnote-continuation-separator:url("file:///C:/DOCUME~1/Martin/CONFIG~1/Temp/msohtml1/01/clip_header.htm") fcs; mso-endnote-separator:url("file:///C:/DOCUME~1/Martin/CONFIG~1/Temp/msohtml1/01/clip_header.htm") es; mso-endnote-continuation-separator:url("file:///C:/DOCUME~1/Martin/CONFIG~1/Temp/msohtml1/01/clip_header.htm") ecs;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:35.4pt; mso-footer-margin:35.4pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> DETERMINATION OF ESTROGENIC ENDOCRINE DISRUPTOR: ETHINYLESTRADIOL, USING MODIFIED MAGNETIC NANOPARTICLES   Martínez NA, Fernández-Baldo MA, Bertolino FA, Sanz MI, Messina GA, Raba J#   Departamento de Química, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis Chacabuco 917, San Luis, Argentina, CP: 5700   Introduction Ethinylestradiol (EE2) is a synthetic estrogen female sex hormone which is used as a contraceptive therapy. The determination of synthetic estrogen has attracted much attention since these compounds were included in the endocrine disrupting chemicals (EDCs) and its able to cause the deleterious reproductive dysfunction of animals and humans (1). Due the problems mentioned previously, is important the determination of EE2 in water samples. Therefore we present a method that combined the use of magnetic nanoparticles (MNPs) modified with anti-EE2 antibodies and square-wave voltammetry (OSWV). The advance in experimental electrochemical techniques in the field of analysis of drugs is due to their simplicity, low cost and relatively short time of analysis when they are compared with the other techniques (2-7). In addition the use of MNPs also have attracted great interest for biological and clinical applications (8–11), and they are widely used as a new agent of preconcentration due to its features, between these: large surface area (12), strong magnetism, improve the adsorption capacity of analytes and avoid the time-consuming enrichment process of loading large volume samples through the rapid isolation of NPs with an adscititious magnet.   Materials and method Electrochemical experiments were performed in unstirred solutions using a BAS 100B/W electrochemical analyzer (Bioanalytical System,West Lafayette, IN). Cyclic and square-wave voltammograms were obtained using a three electrodes system consisted of a glassy carbon (GC) working electrode, an Ag|AgCl|3M NaCl reference electrode and a Pt wire counter electrode. All reagents were of analytical or biochemical grade.   Procedure This method was applied to the determination of EE2 in water samples. 25 mL of sample solution were put into a beaker. Then 175 µg of magnetic nanobeads, previously modified with anti-EE2 antibodies were added to the sample solution. EE2 present in the sample was allowed to react immunological with the modified magnetic beads. Then, after stirring for 10 min, the magnetic nanobeads were recovered using an external magnet and washed three times with 0.01M PBS buffer (pH 7.2) to remove the excess of sample and they were resuspended in 250 µL of H2SO4 pH 2.00 and added in a voltammetric cell for the desorption of EE2; after 2 min, the signal was OSWV.   Results The calibration curve was plotted using ΔI versus concentration of the standard solutions. Calibration curve was found to be linear over of the concentration range 0.03–25 µg L-1. The calibration graph is described by the calibration equation ΔI(nA) = 76.08 + 7.67C EE2with a correlation coefficient of 0.998,  with a limit of detection DL=3SB/m was 0.003 µg L-1.   Conclusions The developed voltammetric technique is suitable for the determination of EE2 in environmental samples after a simple step of preconcentration using modified MNPs. It has the advantages of low cost, wide linear range, reproducibility, accuracy and, more important, low DLs. The developed procedure was successfully applied to water samples.     References   [1]Y. Fan, M. Zhang, S.L. Da, Y.Q. Feng, Analyst 130 (2005) 1065. [2] S.A. Özkan, Y. Özkan, Z. SentuÜrk, Anal. Chim. Acta 453 (2002) 221. [3] A.Z. Abu Zuhri, N.A. Zatar, R.M. Shubietah, H.H. Arafat, Mikrochim. Acta 134 (2000) 153. [4] B. Uslu, S. Yilmaz, S.A. Özkan, Die Pharmazie 56 (2001) 629. [5] F. Belal, H. Abdine, N. Zoman, J. Pharm. Biomed. Anal. 26 (2001) 585. [6] J.J. Berzas, J. Rodriguez, G. Castaneda, M.J. Villasenor, Anal. Chim. Acta 417 (2000) 143. [7] B. Uslu, S.A. .Özkan, H.Y. Aboul-Enein, Electroanalysis 14 (2002) 736. [8] W. Andra, H. Nowak (Eds.), Magnetism in Medicine. A Handbook,Wiley- VCH Verlag, Berlin, 1998. [9] Q.A. Pankhurst, J. Phys. B 36 (2003) R167. [10] S. Mornet, J. Mater. Chem. 14 (2004) 2161. [11] P.C. Lin, M.C. Tseng, A.K. Su, Y.J. Chen, C.C. Lin, Anal. Chem. 79 (2007) 3401. [12] M.H. Liao, D.H. Chen, Biotechnol. Lett. 24 (2002) 1913. # Corresponding author. Tel +54 2652  425385, e-mail: jraba@unsl.edu.ar