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Carbon film based ring‐disk and split‐disk dual electrodes as detectors for microbore liquid chromatography
Author(s) -
Niwa Osumu,
Morita Musao,
Solomon Bruce P.,
Kissinger Peter T.
Publication year - 1996
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.1140080505
Subject(s) - detector , electrode , materials science , dual (grammatical number) , carbon fibers , analytical chemistry (journal) , chromatography , ring (chemistry) , chemistry , optics , physics , composite material , organic chemistry , art , literature , composite number
The electrochemical properties of carbon film based ring‐disk and split‐disk electrodes in small active volume (0.24–2μL) radial flow cells were studied in order to employ them in conjunction with microbore liquid chromatography (LC) for determining catecholamines. The high conversion of dopamine (DA) at the disk of a ring‐disk electrode makes the DA limiting current lower than the theoretical value at a low flow rate. The collection efficiency (CE) increases with decreasing flow rate and cell thickness, which is different from previously reported results. A high CE of 0.96 was achieved because of the narrow gap of 5 μm. On the other hand, a higher limiting current was observed with the split‐disk than with a commercially available dual‐disk electrode because of its efficient geometry for analyte collection. The cross talk of the DA after reacting at one of the electrode is only 2%. The ring‐disk and split‐disk electrodes were suitable as series and parallel electrochemical detectors for small bore LC. A detection limit of 103 fg was obtained for DA at the disk of the ring‐disk because of the high signal in the thin‐layer radial flow cell and the low noise level of the carbon film. In contrast, very slight interference was observed from neighboring electrodes when determining catecholamines at the split‐disk.