High performance capillary electrophoresis electrophoretic methods

Fan et al. [106] developed a high performance capillary electrophoresis method for the analysis of primaquine and its trifluoroacetyl derivative. The method is based on the mode of capillary-zone electrophoresis in the Bio-Rad HPE-100 capillary electrophoresis system effects of some factors in the electrophoretic conditions on the separation of primaquine and trifluoroacetyl primaquine were studied. Methyl ephedrine was used as the internal standard and the detection was carried out at 210 nm. A linear relationship was obtained between the ratio of peak area of sample and internal standard and corresponding concentration of sample. The relative standard deviations of migration time and the ratio of peak area of within-day and between-day for replicate injections were <0.6% and 5.0%, respectively. 

CEC is often inappropriately presented as a hybrid method that combines the capillary column format and electroosmotic flow employed in high-performance capillary electrophoresis with the use of a solid stationary phase and a separation mechanism, based on specific interactions of solutes with the stationary phase, characteristic of HPLC. Therefore CEC is most commonly implemented by means typical of both HPLC (packed columns) and CE (use of electrophoretic instrumentation). To date, both columns and instrumentation developed specifically for CEC remain scarce. 

In conclusion, CE is a valuable analytical tool that offers a number of possibilities for the analysis of a wide spectrum of forensicaUy interesting compounds. Practically all compounds which have been traditionally analyzed by GC, high-performance Uquid chromatography, thin-layer chromatography, or slab-gel electrophoresis, can be assayed by capillary electrophoretic procedures. AU methods of capillary electrophoresis can be validated and can meet the demands of good laboratory practice. 

Electrophoretic separations are currently performed in two quite different formats one is called slab electrophoresis and the other capillary electrophoresis. The first is the classical method ihal has been used for many years to separate complex, high-molecular-mass species of biological and biochemical interest. Slab separations arc carried out on a thin flat layer or slab of a porous semisolid gel containing an aqueous buffer solution within its pores. This slab has dimensions of a few centimeters on a side and, like a chromatographic thin-layer plate, is capable of separating several samples simultaneously. Samples arc introduced as spots or bands on the slab, and a dc electric held is applied across the slab for a fixed period. When the separations are complete, the Held is discontinued and the separated species are visualized by staining in much the same way as was described for thin-layer chromatography in Section 281-2,... 

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. 

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