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Microchip capillary electrophoresis with a boron‐doped diamond electrochemical detector for analysis of aromatic amines
Author(s) -
Shin Dongchan,
Tryk Donald A.,
Fujishima Akira,
Muck Alexander,
Chen Gang,
Wang Joseph
Publication year - 2004
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.200305965
Subject(s) - diamond , electrode , capillary electrophoresis , amperometry , analytical chemistry (journal) , passivation , glassy carbon , detection limit , materials science , electrochemistry , carbon fibers , chemistry , chromatography , nanotechnology , cyclic voltammetry , metallurgy , layer (electronics) , composite material , composite number
The attractive features of a boron‐doped diamond (BDD) thin‐film detector for microchip capillary electrophoretic (CE) separations of dye‐related amino‐substituted aromatic compounds are described. The diamond electrode was employed in the end‐column amperometric detection of 4‐aminophenol (4‐AP), 1,2‐phenylenediamine (1,2‐PDA), 2‐aminonaphthalene (2‐AN), 2‐chloroaniline (2‐CA), and o ‐aminobenzoic acid ( o ‐ABA), and its attractive behavior was compared to commonly used screen‐printed carbon and glassy‐carbon electrodes. These conventional electrode materials exhibit a significant degree of passivation and low sensitivity to the above‐mentioned environmental pollutants. The diamond‐based electrochemical detection system displayed a favorable analytical performance, including lower noise levels, higher peak resolution with enhanced sensitivity, and improved resistance against electrode passivation. Factors influencing the on‐chip analysis were assessed and optimized. The diamond detector displayed detection limits of 2.0 and 1.3 μ M for 4‐AP and 2‐AN, respectively, and a wide linear response for these compounds over the 2–50 μ M range. The enhanced stability was demonstrated by relative standard deviation (RSD) values of 1.4% and 4.7% for 100 μ M 1,2‐PDA and 200 μ M 2‐CA, respectively, for repetitive detections ( n = 7). Besides, the simultaneously observed current decrease was 2.4 and 9.1% for 1,2‐PDA and 2‐CA, respectively (compared to 21.8 and 41.0% at the screen‐printed carbon electrode and 28.3 and 34.1% at the glassy carbon electrode, respectively). The favorable properties of the diamond electrode indicate great promise for environmental applications in CE and other microchip devices.