IQUIFIB   02644
INSTITUTO DE QUIMICA Y FISICOQUIMICA BIOLOGICAS "PROF. ALEJANDRO C. PALADINI"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Synthesis of polymeric particles and their application as pseudostationary phase in capillary electrochromatography for peptide separation
Autor/es:
GRELA, DENISE A.; COLLAZO, DAIANA; ZANNONI, VALERIA; VIZIOLI N
Lugar:
Natal
Reunión:
Simposio; 20th Latin-American /symposium on Biomedical, Biopharmaceutical, and Industrial Applications of Capillary Electrophoresis; 2014
Resumen:
At the
present time, pseudostationary phases have turned an interesting alternative in
capillary electrochromatography (CEC). On one hand, pseudostationary phases
provide sites for analyte interaction and not require either frits or packing; on
the other hand, this system does not need a column change, since a renewed
column is used for each analysis.[1]
The aim
of this work was to evaluate the interaction between a mixture of five synthetic
peptides and synthesized polymer particles acting as pseudostationary phase in CEC.
Particles
(Z-Average 440 nm - 640nm) were prepared from methacrylic acid and
ethylenglycol dimethacrylate with benzoyl peroxide as radical initiator by
utilizing a precipitation polymerization technique. The methacrylic acid (pKa
4.65) provides acid groups to the polymer. Different total monomer
concentrations were tested, from 2 % to 6 %, in order to modify the size of the
particles.
After
synthesis, the resulting particles were removed from its synthesis medium eliminating
the solvent and unreacted monomers. Then, an aqueous suspension of particles
was used as pseudostationary phase in CEC. Once the capillary was filled with the
background electrolyte (BGE), particles in suspension were introduced
hydrodinamically at 0.7 psi for 4.0 s. Immediately, sample was also introduced
hydrodinamically at 0.3 psi for 3.0 s, and then voltage was applied. This
procedure is known as "partial filling technique". BGE was composed
of 25 mM of sodium phosphate buffer solution, and was adjusting at different
pHs (from 5.0 to 8.0).
The
results showed that at pH 7.0 electroosmotic flow was not affected by the
presence of the particles and peaks corresponding to bradykinin and luteinizing
hormone-releasing hormone (LHRH) were not present. Angiotensin I, oxytocin and
methionine-enkephaline presented no change in their migration time. However,
angiotensin I and oxytocin peak areas decreased.
These findings suggest that particles have a
strong interaction with basic peptides, bradykinin and LHRH, at pH 7.0
(particles with negative charge and peptides with positive charge). This
behavior was observed with peptides migrating faster in the capillary, which
were the ones with high positive net charge, and decrease as long as peptides
presented less positive net charge.