Covalently modified graphitic carbon-based stationary phases for anion chromatography

Analyst Pub Date: 2009-09-02 DOI: 10.1039/B911988D

Abstract

Carbon-clad zirconia particles have been converted into ion-exchange media by in situdiazonium generation and thermal deposition. The surfaces prepared possess either a permanently charged anion-exchange site or a weak anion-exchange site. Surface modification optimization experiments were performed both on planar carbon surfaces and on non-porous 2 μm and porous 3 μm carbon-based particles. Modification by traditional electrochemical and thermal deposition were compared. Surface modification with the tertiary amine functionality, N,N-dimethyl-p-phenylenediamine, yielded a capacity of 6.5 μequiv./column, stable retention for >33?000 column volumes and retention reproducibility of <2% RSD. A quaternary amine functionality (strong base exchanger) was achieved by reaction of the tertiary amine phase with methyl iodide. Utilizing short columns (35 × 4 mm i.d.) mixtures of common inorganic anions were separated with efficiencies of 21?000 plates/m.

Graphical abstract: Covalently modified graphitic carbon-based stationary phases for anion chromatography
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