Page 109 - Analytical Electrochemistry 2d Ed - Jospeh Wang

94 CONTROLLED-POTENTIAL TECHNIQUES

FIGURE 3-27 Three-dimensional chromatogram for oxidizable biological compounds at a
multichannel amperometric detection system, consisting of an array of 16 carbon-paste
electrodes held at different potentials. AA ˆ ascorbic acid; NE ˆ norepinephrine; DOPAC ˆ
3,4-dihydroxyphenylacetic acid; 5-HIAA ˆ 5-hydroxyindole-3-acetic acid; DA ˆ dopamine;
HVA ˆ homovanillic acid. (Reproduced with permission from reference 68.)

the array provides con®rmation of peak purity and improved identi®cation of target
analytes. Additional information can be achieved by using arrays comprising
different electrode materials (see Section 6-4). For a more detailed description of
on-line electrochemical detectors, the reader is referred to a monograph by Stulik
and Paca Âkova  (69). Comparison of various commercial detectors is also available
(70).

REFERENCES

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8. J. Osteryoung and R.A. Osteryoung, Anal. Chem., 57, 101A (1985).
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