On-column electrochemical detector with a single graphite fiber electrode for open-tubular liquid chromatography

Microcolumn liquid chromatography: instrumentation, detection and applications

“…The initial developments in miniaturized electro- chemical detection -or the use of micro-electrodeswere reported for open tubular liquid chromatography by the groups of Manz [173,174] and Jorgenson [175,176], which were later also applied in microcolumn LC [63,95,177]. Such detectors typically consist of a small wire that is placed into the outlet of an open tubular column.…”

“…For instance, Manz and Simon [173,174] used a 1-1~m diameter ionselective electrode for the potentiometric detection of K + ions. Jorgenson et al constructed a 9-1xm diameter carbon electrode for the amperometric detection of catechols and ascorbic acid [175], and for the voltammetric analysis of hydroquinone and catechol. Detection limits achievable with these detection schemes are in the fmol-pmol range.…”

“…The major limitation of voltammetry is the approximately 100-times worse mass sensitivity compared to amperometric detection [16]. Voltammetric detection has been applied in open tubular chromatography [175,176] and conventional liquid chromatography [183][184][185], but has found only little acceptance in microcolumn LC so far. An exception is the work of Goto and Shimada [182] who presented a rapid-scanning electrochemical voltammetric detector for capillary LC.…”

Analytical chemistry in microenvironments: single nerve cells

“…This is, of course, a major advantage in the use of electroosmotic flow over externally applied pressure to acquire cellular or cytoplasmic samples. Sensitive amperometric detection schemes have been developed for both OTLC (40) and capillary electrophoresis (4,38). In both of these systems, detection is accomplished using a small carbon fiber electrode placed inside the end of the capillary.…”

High-performance capillary electrophoresis

“…For example, surfactants with chiral chelates at the polar side can be used for chiral separations. We have separated D,L-dansylated amino acids using such a chelating surfactant and Cu (11). Thus, the selectivity of chromatography can be combined with the efficiency of capillary electrophoresis.…”