High voltage electric field separators

The ultrafiltration of the microemulsion is a very useful operation for separating water and oil in these mixtures [117-120]. Because of the limited availability of solvent stable membranes, most of the work pubHshed so far was performed using ceramic membranes, which show a high adsorption of surfactant at the membrane surface and comparably low rejection rates of reverse micelles. Using electro ultrafiltration, where the concentration polarisation phenomenon of the reverse micelles (using the ionic surfactant AOT) at the membrane surface is depressed by asymmetric high voltage electrical fields, the rejection rates can be increased,but not to economical values [121,122]. 

Once the molecular ions are produced they are usually accelerated and focused, using high-voltage electric fields and suitable electrodes, prior to injection into the mass analyser. A number of different mass analysis methods are now in use, and new techniques are continually being developed. However, all the methods described here share one thing in common they all separate ions on the basis of the mass/charge ratio mjz). 

As the name implies, CE separates sample components within the lumen of a narrow-bore capillary (20 to 150 pm) filled with a buffered electrolyte. High electric fields (hundreds of volts/centimeters in practice, but sometimes in excess of 1000 V/cm) can be used in CE because the capillary contains a small volume of electrolyte and a relatively large surface area to dissipate the heat generated by the electric current (Joule heat). High-voltage applications result in reduced analysis time and therefore less diffusion. 

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