Contents



**in Ingestive Behavior 71** Elsa Lamy, Martine Morzel, Lénia Rodrigues, Cristina Pinheiro, Ana Rodrigues Costa, Célia Miguel Antunes, Orlando Lopes and Fernando Capela e Silva

## Preface

Electrokinetic phenomena were discovered quite early in the nineteenth century. Hence in‐ vestigations in the field have been conducted for more than a century and a half. The discov‐ ery of electroosmosis and electrophoresis by Reuss occurred soon after the first investigations on the electrolysis of water by Nicholson or Carlisle and the electrolysis of salt solutions by Berzelius (1804) and Davy (1807). Reuss carried out two experiments, the first demonstrated the effect known as electroosmosis, and the second was actually the dis‐ covery of electrophoresis.

Field effect electroosmosis is a novel interfacial phenomenon which is of particular interest. Field effect could be demonstrated by combining a metal-insulator-electrolyte system (MIE) with capillary electroosmosis. Using this technique a capillary at its outside surface and elec‐ troosmatic flow is controlled by applying a perpendicular electric field to the flow.

The potential application of this effect is examined in the process which would benefit from a flexible control of electroosmatic flow, such as capillary electrophoresis in separation sci‐ ence.

Electrophoresis experiment was first carried out by Tiselius in 1930. In his thesis titled "The Moving Boundary Method of Studying the Electrophoresis of Proteins", Tiselius utilized the electric charge carried by the macromolecules to achieve some pioneering separation of blood plasma proteins in free solution on a photographic film. Application of electrophore‐ sis experiment is defined as the transport of electrically charged particles in a direct current electric field. Electrophoretic separation is based on differential rates of migration in the bulk of the liquid phase and is not concerned with reactions occurring at the electrodes. In the early days, electrophoresis was carried out either in free solution or in the supporting media such as paper, cellulose acetate, starch, agarose, and polyacrylamide gel. Between 1950 and 1970, an enumeration of techniques and instrumentation for electrophoresis were developed.

Gel electrophoresis has been rarely used for the separation and identification of small charg‐ ed molecules of molecular weight less than about 1000 Dalton. In addition, the major draw back of gel electrophoresis is lack of complete automation.

To overcome the low efficiency and reduce thermal effects, Hjerten carried out electrophore‐ sis in narrow diameter tubes of 300 µm internal diameter for the first time in 1967.

This was the birth of open tubular capillary electrophoresis. However, in the following dec‐ ade, capillary electrophoresis did not draw enough attention from researchers, until 1981 when Jorgenson and Lukacs demonstrated the use of narrow capillaries to produce high ef‐ ficiency for the separation of dansy and fluorescamine derivatives of amino acids, dipepti‐

des and simple amines, high performance capillary electrophoresis was born and a new era of capillary electrophoresis began. After the introduction of commercial CE instrument in late 1988 that allowed the full automation of CE analysis to be possible, more and more re‐ search publications and industrial applications have made capillary electrophoresis one of the dominant technologies in the separation field. In 1985 Terabe et al. added a new dimen‐ sion to capillary electrophoresis. They added micelles to the aqueous electrolyte and were able to separate neutral molecules such as benzene and phenol.

With this technique it is possible to separate various drugs which are neutral or even charg‐ ed. One that can separate enantiomers by this technique is called micellar electrokinetic ca‐ pillary chromatography (MECC).

The present book contains few fundamentals on capillary electrophoresis and diverse appli‐ cations of electrophoresis in general. We hope this collection will be useful for the interested readers.

> **Kiumars Ghowsi** Department of Chemistry, Majlesi Branch, Islamic Azad University, Isfahan, Iran

**Field Effect Electrophoresis**

des and simple amines, high performance capillary electrophoresis was born and a new era of capillary electrophoresis began. After the introduction of commercial CE instrument in late 1988 that allowed the full automation of CE analysis to be possible, more and more re‐ search publications and industrial applications have made capillary electrophoresis one of the dominant technologies in the separation field. In 1985 Terabe et al. added a new dimen‐ sion to capillary electrophoresis. They added micelles to the aqueous electrolyte and were

With this technique it is possible to separate various drugs which are neutral or even charg‐ ed. One that can separate enantiomers by this technique is called micellar electrokinetic ca‐

The present book contains few fundamentals on capillary electrophoresis and diverse appli‐ cations of electrophoresis in general. We hope this collection will be useful for the interested

**Kiumars Ghowsi**

Majlesi Branch,

Isfahan, Iran

Department of Chemistry,

Islamic Azad University,

able to separate neutral molecules such as benzene and phenol.

pillary chromatography (MECC).

readers.

VIII Preface
