Capillary and microchip electrophoresis in microdialysis: Recent applications

Abstract

The theme of this review is to highlight the importance of microscale electrophoretic-based separation systems in microdialysis (microD). The ability of CE and MCE to yield very rapid and highly efficient separations using just nanolitre volumes of microdialysate samples will also be discussed. Recent advances in this area will be highlighted, by illustration of some exciting new applications while the need for further innovation will be covered. The first section briefly introduces the concept of microD sampling coupled with electrophoresis-based separation and the inherent advantages of this approach. The following section highlights some specific applications of CE separations in the detection of important biomarkers such as low-molecular-weight neurotransmitters, amino acids, and other molecules that are frequently encountered in microD. Various detection modes in CE are outlined and some of the advantages and drawbacks thereof are discussed. The last section introduces the concepts of micro-total analysis systems and the coupling of MCE and microD. Some of the latest innovations will be illustrated. The concluding section reflects on the future of this important chemical alliance between microD and CE/MCE.

Capillary and Microchip Electrophoresis

“…The obtained linear calibration graph logP ow ¼ a log k þ b (where a and b are constants obtained by regression analysis) is used for calculation of a log P ow coefficient from an experimentally determined k value. A 96-capillary multiplexed MEEKC system with UV absorption detection [184,185] was shown to be a high-throughput, rapid, accurate and reproducible approach for the determination of log P ow values [108]. Formation constants and mobilities of complexes formed in solution can be determined by CZE (used for complexation of metals and small molecules with ligands) and ACE (used for the study of the interaction between an analyte and an affinity probe).…”

“…It can be employed for the continuous monitoring of small molecules and ions present in aqueous samples, including in vivo monitoring, process chemistry, and environmental analysis. Both capillary-based and microchip setups can be used [184,185]. It is important to realize that commercial capillary and microchip instruments do operate with small sample quantities (nanoliter and picoliter amounts, respectively); however, sample vials used for the introduction of the sample require microliter quantities (typically !…”

A review of microdialysis coupled to microchip electrophoresis for monitoring biological events

“…The most common method used for off-line separation-based analysis is liquid chromatography [15,18]. However, over the past twenty years, capillary electrophoresis has become increasingly popular [15,18-20]. An advantage of capillary electrophoresis for off-line analysis is that, because capillary electrophoresis only requires nanoliter amounts of sample, a single 1–10 μL microdialysis sample can be analyzed for several different classes of analytes by multiple capillary electrophoresis methods [21-23].…”

Equine laminitis: a tissue microdialysis study of lamellar bioenergetics

“…In essence, the procedure is a diffusion-based sampling technique for the collection of freely available, low molecular weight molecules (Guihen and O'Connor, 2010). The probe is a tubular structure with a lumen.…”

“…The principle of microdialysis is based on the placement of a semi-permeable membrane in the tissue of interest (Bito et al, 1966;de Lange et al, 2000;Guihen and O'Connor, 2010). The membrane allows water and solutes to diffuse between the interstitial fluid (IF) and the perfusate (which is usually free of the substances to be analyzed) (Benveniste, 1989).…”