HPCE high performance capillary methods

A high performance capillary electrophoresis (HPCE) was described for the separation and simultaneous determination of OTC, TC, CTC, DC, and chloramphenicol in honey. The use of buffer pH 3.2 containing 0.02 mol/L Na2HP04 and 0.01 mol/L citric acid with addition of 4% (v/v) A-methylmorpholine and 12% (v/v) acetonitrile demonstrated a good separation of these five antibiotics within 20 min. The proposed method gave detection limit (signal to noise ratio > 5) of 20 pg/L for OTC [26],... 

Shibukawa et al. (40) discussed the frontal analysis method, also called high-performance frontal analysis (HPFA) or high-performance capillary electrophoresis/frontal analysis (HPCE/FA), compared it to conventional methods, and focused on the application to stereoselective protein binding. The affinity of the drugs warfarin, verapamil, and carbamazepine and the drug candidate BOF-4272 to HSA was investigated. 

In this book, the focus is on the use of high performance liquid chromatography (HPLC) for the separation and detection of biochemical components produced from enzymatic reactions. But the purpose of the book is also to introduce HPLC and high performance capillary electrophoresis (HPCE) as methods applicable for separation and detection of a variety of components, even those not produced by enzymatic reactions. 

Using these criteria as yardsticks, the first edition has been a success. It is now obsolete, however Because of the increases in both number and types of activities assayed, it is no longer an accurate catalog of enzymatic activities investigated by means of the HPLC method. For this work to continue to serve as a reference source, it would need updating. While it was the obsolescence of the first edition that in part prompted the development of a second edition, there were other considerations as well. These included the introduction of high performance capillary electrophoresis (HPCE) as a method for separation, the development of microdialysis as a method for collection of samples... 

A very interesting task would be automatic measurement of the product and the calculation of production rates. This would allow automatic optimization of the process by a computer program that varies all relevant parameters, probably by multiparameter analysis, to find the best production conditions. As long as there are no product sensors available, the main problem may be the time necessary for the measurement of an automatically taken sample. However, the use of HPLC methods can give accurate results within 20 min, and high-performance capillary electrophoresis (HPCE), with an analysis time of 5 min, could be introduced (Beckman PIACE 2(X)0, E. Wasserbauer, personal communication and James et al, 1994). Nonetheless, further development is necessary before these methods can be used routinely for automatic fermentation analysis. 

Although not completely correct, CEC is often presented as a hybrid method that combines the capillary column format and EOF typical of high-performance capillary electrophoresis (HPCE) with the use of a solid stationary phase and a separation mechanism based on specific interactions of solutes with a stationary phase characteristic of HPLC. Therefore, CEC is most commonly implemented by means typical of both HPLC (packed columns) and HPCE (electrophoretic instrumentation). To date, both columns and instrumentation developed specifically for CEC remain scarce. 

During the last decades the different modes of capillary electrophoresis (CE) have developed into high-performance (HPCE) separation methods, offering a high separation efficiency (lO -lO theoretical plates), high sensitivity (femtomole to zeptomole amounts in nano- to picoliter sample volumes), and short analysis times (typically 5-20 min, in special cases only a few seconds). They are considered as a recognized complement and/or coimterpart of liquid chromatography (LC) and gel electrophoretic methods. 

Because HPLC and HPCE are based on different physico-chemical principles, HPCE may be expected to address areas in which HPLC has shortcomings [884]. One such area is time of separation. In terms of speed of analysis, selectivity, quantitation, methods to control separation mechanism, orthogonality, CE performs better than conventional electrophoresis and varies from HPLC (Table 4.49). CE has very high efficiency compared to HPLC (up to two orders of magnitude) or GC. For typical capillary dimensions 105—106 theoretical plates are common in CE compared to 20 000 for a conventional HPLC column and... 

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