Capacitively coupled contactless conductivity detection in capillary electrophoresis

Abstract

Capacitively coupled contactless conductivity detection (C(4)D) has become an accepted detection method in capillary electrophoresis (CE) for a variety of analytes. Advantages of this technique over optical detection modes and galvanic contact conductivity detection include great flexibility in capillary handling and rather simple mechanical parts and electronics, as it can be performed in an on-capillary mode. Furthermore, the detection principle can be used with capillaries made of other materials than fused silica (PEEK, Teflon), with chip-based separation technologies, or with capillaries having very small inner diameters. This review presents a discussion of the published literature on C(4)D for CE and capillary electrochromatography.

Identification of inorganic ions in post‐blast explosive residues using portable CE instrumentation and capacitively coupled contactless conductivity detection

“…An acetate/His (pH 4.1) BGE was found to provide good peak shapes but some peak overlaps occurred. However, addition of HIBA [25] and 18-crown-6 ether permitted all 11 target cations to be separated. The final BGE composition was 50 mM acetic acid, 10 mM His, 0.7 mM 18-crown-6 ether and 1 mM HIBA at pH 4.1 and the corresponding separation is shown in Fig.…”

“…Conductivity detection is the most universal form of detection for inorganic ions and, in the case of CE separations, capacitively coupled contactless conductivity detection (C 4 D) has been used with increasing frequency over recent years (for recent reviews see [18,[25][26][27]. Detection limits are in the range 10…”

Direct determination of valproic acid in biological fluids by capillary electrophoresis with contactless conductivity detection

“…An internal metallic shield completely encloses the excitation part of the detector cell, except for a small hole through which the capillary is passed, in order to eliminate any direct coupling between the electrodes. More detailed descriptions are given in the previous papers of one of our research groups [41,[46][47][48][49][50][51]. HTAB at pH 6.0 was used as running electrolyte solution.…”

Bioanalytical profile of the l-arginine/nitric oxide pathway and its evaluation by capillary electrophoresis

“…Slightly different CCD techniques were proposed for HPCE in 1998 [304,305] and subsequently improved (for reviews see refs. [306][307][308][309][310]). In CCD, the impedance is measured as a function of the cell capacitance value which depends on multiple factors, including the dielectric (conductivity) profile of environment and the geometry of cell and electrodes.…”

“…In addition to the rapid progress of CZE/CCD technology for fused silica capillaries, several on-chip platforms have been proposed (for recent reviews see refs. [294,[308][309][310]323]). In summary, CCD is a very potent and promising technique for both fused silica capillary-and micro-chip-based CZE platforms; however, applications focusing on profiling of L-arginine/NO pathway in biological samples have yet to be developed.…”