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Iron protoporphyrin‐modified monolithic support for on‐line preconcentration of angiotensin prior to CE analysis
Author(s) -
Yone Ángel,
Rusell María Lucía,
Grasselli Mariano,
Vizioli Nora M.
Publication year - 2007
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.200600706
Subject(s) - protoporphyrin , chemistry , line (geometry) , protoporphyrin ix , angiotensin ii , chromatography , materials science , biochemistry , organic chemistry , receptor , photodynamic therapy , porphyrin , geometry , mathematics
An on‐line preconcentration method using a polymeric monolithic support is proposed for the retention of the decapeptide angiotensin I and its subsequent analysis by CZE. Monolithic capillary columns were prepared in fused‐silica (FS) capillaries of 150 μm id by ionizing radiation‐initiated in situ polymerization and cross‐linking of diethylene glycol dimethacrylate and glycidyl methacrylate, and chemically modified with iron protoporphyrin IX (Fe‐ProP). Monolithic microcolumns (8 mm long) were coupled on‐line to the inlet of the separation capillary (FS capillary, 75 μm id ×10 cm from the inlet to the microcolumn and 27 cm from the microcolumn to the detector). Angiotensin I was released from the sorbent by a 50 mM sodium phosphate, pH 2.5/ACN, 75:25 v/v solution and then analyzed by CZE with UV absorption detection at 214 nm. The concentration LOQ (CLOQ) was 0.5 ng/mL. The Fe‐ProP‐derivatized monolithic microcolumn coupled to the separation capillary exhibited a high retention capacity for peptide angiotensin I, and showed as much as 10 000‐fold improvement in concentration sensitivity.