Continuous electrophoresis system

As in CE, changing system variables (e.g., pH, ionic strength, additive concentration) is very easy in any of the continuous free flow electrophoresis systems reported here because all the interactions take place in free solution. Indeed, changing system variables may be easier in continuous free flow electrophoresis systems than in a CE system because there are essentially no wall effects. Of course, changing system variables in the continuous free flow electrophoresis apparatus may also be easier... 

The author would like to acknowledge R S Technologies, Inc. (Wakefield, RI, USA) for the loan of the continuous free flow electrophoresis system, and Cerestar, Inc. for the donation of the sulfated cyclodextrin. The author would also like to thank Drs. Chris Welch and Prabha Painuly for helpful discussions. 

Capillary zone electrophoresis coupled with fast cyclic voltammetric detection was developed by Zhou et al. [27] for the separation and determination of OTC, TC, and CTC antibiotics. All compounds were well separated by optimization of pH and complexation with a boric acid sodium tetraborate buffer. The detection limit using fast on-line cyclic voltammetric detection with Hg-film-microm electrode was 1.5 x 10-6 mol/L for OTC (signal to noise ratio > 2). A continuous flow manifold coupled on-line to a capillary electrophoresis system was developed by Nozal et al. [28] for determining the trace levels of OTC, TC, and DC in surface water samples. 

The choice of native electrophoresis system depends on the particular proteins of interest. There is no universal buffer system ideal for the electrophoresis of all native proteins. Both protein stability and resolution are important considerations in buffer selection. Recommended choices are the Omstein-Davis discontinuous system21-24 and McLellan s continuous buffers.25... 

Figure 8.5 Effect of pH on protein mobility. Hemoglobin A (pi 7.1) and Hemoglobin C (pi 7.4) were electrophoresed in eight of the McLellan native, continuous buffer systems (Table 8.1). The diagram is drawn to scale. Migration is from top to bottom as shown by the vertical arrows. Bands marked A or C indicate the positions of the two hemoglobin variants in each gel representation. The polarities of the voltages applied to the electrophoresis cell are indicated by + and - signs above and below the vertical arrows. Run times are shown below the arrows. Note the polarity change between the gel at pH 7.4 and the one at pH 8.2. This reflects the pis of the two proteins (and was accomplished by reversing the leads of the electrophoresis cell at the power supply).

Fig. 62a, b, and c. Some staining techniques adapted to paper electrophoresis. Sample human serum. Run continuous electrophoresis. The fractions are labeled according to the proposed reference system (see text). The known fractions are +86.20 Albumin +86.18 oij-globulin +86.12 a2-globulin +86.07 3-globulin —86.02 Y-globulin. 

Fang, Q., Xu, G.-M., Fang, Z.-L., High throughput continuous sample introduction interfacing for microfluidic chip-based capillary electrophoresis systems. Micro Total Analysis Systems, Proceedings 5th XTAS Symposium, Monterey, CA, Oct. 21-25, 2001, 373-374. 

From the area of thermal process engineering, the mass and heat transfer in stirred vessels and in bubble columns is treated. In the case of mass transfer in the gas/liquid system, coalescence phenomena are also dealt with in detail. The problem of simultaneous mass and heat transfer is discussed in association with film drying and in continuous electrophoresis. 

I) Zone electrophoresis, an electrophoretic separation technique, conducted In a continuous buffer system. Samples are Injected and move under the applied field they separate into distinguishable zones If their mobilities are sufficiently apart. 

High throughput continuous sample introduction interfacing for microfluidic chip-based capillary electrophoresis systems. Micro Total Analysis Systems... 

Electrophoresis of proteins under high hydrostatic pressures Table 1. Some continuous buffer systems for polyacrylamide-gel electrophoresis ... 

Zone electrophoresis is a separation method based on the different net mobility of ions in a continuous electrolyte system. In zone electrophoresis (Fig. 1) the entire system is uniformly filled with a single electrolyte of a relatively high concentration, which determines the electrical properties of the system as well as the pH. When an electrical potential U is applied to the system of a passable length L, an electric field of a uniform strength E is established, given by... 

Stalcup aiid co-workers [14] adapted this method to a continuous elution mini-prep electrophoresis apparatus shown in Fig. 11-3. In this apparatus, the end of the electrophoretic gel is continuously washed with elution buffer. The eluent can then be monitored using an HPLC detector (Fig. 11-4) and sent to a fraction collector where the purified enantiomers, as well as the chiral additive, may be recovered. In this system, the gel configuration was approximately 100 mm x 7 mm, and was aircooled. The number of theoretical plates obtained for 0.5 mg of piperoxan with this gel was approximately 200. A larger, water-cooled gel was able to handle 15 mg of... 

In order to illustrate the effects of media structure on diffusive transport, several simple cases will be given here. These cases are also of interest for comparison to the more complex theories developed more recently and will help in illustrating the effects of media on electrophoresis. Consider the media shown in Figure 18, where a two-phase system contains uniform pores imbedded in a matrix of nonporous material. Solution of the one-dimensional point species continuity equation for transport in the pore, i.e., a phase, for the case where the external boundaries are at fixed concentration, Ci and Cn, gives an expression for total average flux... 

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