Electrochemical analysis methods electrophoresis

Modern tHcy methods include enzyme immunoassays and chromatographic-based methods. In practice, immunoassays " are most often used for routine purposes (e.g., fluorescence polarization immunoassay IFPIA] as run on Abbott s IMx and AxSYM platforms) Chromatographic assays include amino acid analysis high-performance liquid chromatography (HPLC) with ultraviolet, fluorescence, or electrochemical detection ° " capillary electrophoresis with fluorescence detection gas chromatography-mass spectrometry (GC-MS) and liquid chromatography with tandem MS (MS-MS). 

Microdialysis is a sampling technique that must be coupled with an analytical method to identify and quantify chemical components of the dialysate. The samples can be analyzed immediately upon collection (i.e., online), or they can be stored (—80°C) for future analysis. Only analytical techniques sensitive enough to measure both small sample volumes and low concentrations of substances can be used to measure compounds in dialysate samples. High-performance liquid chromatography (HPLC) or capillary electrophoresis (CE) combined with ultraviolet (UV), electrochemical (EC), or laser-induced fluorescence (LIF)... 

Capillary electrophoresis (CE) has also been employed for the analysis of flavonols.17 In fact, CE methods coupled with electrochemical detection (ECD) are increasingly being employed for the analysis of flavonoids because of the minimal sample volume required, short analysis time, and high separation efficiency.17 The limit of detection for quercetin and kaempferol by CE/ECD methods are comparable to those obtained by LC/MS. The primary drawback of using CE is low repeatability of retention times as compared with HPLC. 

The analyses carried out up to now on such extracts have been based upon differences of solubility (see p. 235). The discussion of the results obtained has made clear that a reinvestigation of these mixtures is necessary in order to define more accurately the structure proteins of fish muscle. Electrophoresis, which permits the analysis of such mixtures with a minimum of alteration, appears a particularly suitable method. It has been applied as yet only to carp muscle extracts of high ionic strength (Hamoir, 1951b, 1954, 1955). In view of the very constant electrochemical behavior of the muscle structure proteins (see Hamoir, 1953a), it seems safe to assume that similar results will be obtained with other fishes. The results already obtained will therefore be more extensively described. The slight difference in extractibility previously mentioned between white and red rabbit muscles (Crepax, 1952) suggests that a separate study of both fish muscles would also be desirable in this case, but it has not yet been undertaken. 

DNA and RNA are complex biomacromolecules whose structures and interactions are intensively studied mainly in relation to their biological roles. The main interest of scientists is not oriented to the determination of nucleic acids in biological materials but to analysis of their nucleotide sequence, secondary and tertiary structures, specific interactions with proteins, etc. A number of diverse techniques are necessary such as absorption spectroscopy, chromatography, gel electrophoresis, and radioactive and nonradioactive labeling, which can be found in almost every nucleic acid laboratory, while other less universal techniques are applied in relation to the specific aims of the given laboratory. Electrochemical methods briefly reviewed in this article belong to the latter category. They can be extremely useful for a number of purposes, such as determination of traces... 

In addition to chromatographic techniques, several methods have been used for the determination and analysis of vitamins in different samples, such as immunoassays [34] and electrochemical [6] and capillary electrophoresis [39],... 

Electrophoresis is concerned with the migration of particles under the influence of an external field. First, electrophoretic velocities were measured by the same experimental methods as those used by Hittorf (around 1853) for transport numbers. The method was remarkably developed and refined by Tiselius (1937, Nobel Prize in 1947). Since then, there have been a large number of applications in biology and medicine, in particular in the analysis of sera and the separation of amino acids and proteins. Recently, the technique was improved by coupling capillary electrophoresis to an electrochemical detector (CEEC) that can be implanted in vivo for studying microdialysis [4]. 

---