Electrokinetic separations

Overbeek, JTG Bijsterbosch, BH, The Electrical Double Layer and the Theory of Electrophoresis. In Electrokinetic Separation Methods Righetti, PG van Oss, CJ Vanderhoff, JW, eds. Elsevier/North-Holland Biomedical Press , 1979 1. 

Apart from paints, electrokinetic separations find limited application for synthetic polymers [905], mainly because of solvent compatibility (CE is mostly an aqueous technique) and competition of SEC (reproducibility). Reasons in favour of the use of CE-like methods for polymer analysis are speed, sample throughput and low solvent consumption. Nevertheless, CE provides some interesting possibilities for polymer separation. Electrokinetic methods have been developed based on differences in ionisation, degree of interaction with solvent constituents, and molecular size and conformation. 

Recently a decreased level of CE activity has been noticed with a shift of attention towards other separation techniques such as electrochromatography. CE is apparently not more frequently used partly because of early instrumental problems associated with lower sensitivity, sample injection, and lack of precision and reliability compared with HPLC. CE has slumped in many application areas with relatively few accepted routine methods and few manufacturers in the market place. While the slow acceptance of electrokinetic separations in polymer analysis has been attributed to conservatism [905], it is more likely that as yet no unique information has been generated in this area or eventually only the same information has been gathered in a more efficient manner than by conventional means. The applications of CE have recently been reviewed [949,950] metal ion determination by CE was specifically addressed by Pacakova et al. [951]. 

Altria, K. D., and Rogan, M. M. (1990). Reductions in sample pretreatment requirements by using high-performance capillary electrokinetic separation methods. J. Pharm. Biomed. Anal. 8, 1005-1008. 

S Terabe, K Otsuka, K Ichikawa, A Tsuchiya, T Ando. Electrokinetic separations with micellar solutions and open-tubular capillaries. Anal Chem 56 111-113, 1984. 

S. Terabe, K. Otsuka, K. Ichikawa, A. Tsuchiya, and T. Ando, Electrokinetic Separations with Micellar Solutions and Open Tubular Capillaries, Anal. Chem. 1984,56, 111 ibid., 1985,57. 834. 

The treatment methods for remediation of energetic materials from soils are divided on in situ and ex situ biological (bioremediation, phytoremediation, composting), in situ and ex situ physico-chemical (adsorption, oxidation, electrokinetic separation, extraction, solidification, reduction, soil washing), in situ and ex situ thermal (pyrolysis, desorption) [1]. Among the above described... 

Detection limits for 13 resolved PTH-amino acids ranged from 1.6 to 4.8.10 M, which was by a factor of ten superior to the detection limits reported for micellar electrokinetic chromatography [77]. Most of this improvement in detection limit is due to the higher thermo-optical enhancement produced by the high acetonitrile content in the buffer compared to the aqueous mobile phase used in the micellar electrokinetic separation. 

Certain fundamental characteristics of MECC that influence retention have been investigated (5). The technique has been used in the analysis of a variety of samples including phenolic compounds (1), phenylthiohydantoin—amino acids (6), and metabolites of vitamin Bg (7). In related electrokinetic separation techniques, substituted benzene compounds have been separated based on the formation of inclusion complexes with an ionic cyclodextrin derivative in the mobile phase (8) and polyaromatic hydrocarbons have been separated based on solvophobic interactions with a tetraakyl— ammonium ion in the mobile phase (9). The effects of injection procedures on efficiency have also been studied (10). 

Luong JHT, Guo Y. Mixed-mode capillary electrokinetic separation of positional explosive isomers using sodium dodecyl sulfate and negative-P-cyclodextrin derivatives. J Chromatogr A 1998 811 225. 

Electrokinetic Separation Methods, P.G. Righettl, C.J. van Oss and J.W. Vanderhoff, Eds., Elsevier (1979). (Emphasis on antlconvectant techniques experiments and analytical applications.)... 

Lee, H.S. Hong, J. Chiral and electrokinetic separation of amino acids using polypyrrole-coated adsorbents. J. Chromatogr., A 2000, 868, 189-196. 

Righetti, P. G. van Oss, C. J. Vanderhoff, J. W. Electrokinetic Separation Methods. Elsevier/New Holland Biomedical Press Amsterdam, 1979. 

Theoretical Considerations in Electrokinetic Separations. Models have been proposed for electrophoretic (52) and electrochromatographic systems. Similar to developments in chromatography, we may write a model equation for these systems ... 

Vanderhoff, J.W. Micole, F.J. Electrokinetic Separation Methods. Elsevier, Holland. 1979, 81-93. 

Popov K, Kolosov A, Yachmenev VG, Shabanova N, Artemyeva A, Frid A, Kogut B, Vesnovskii S, Sukharenko V. (2001). A laboratory-scale study of applied voltage and chelating agent on the electrokinetic separation of phenol from soil. Separation Science and Technology 36(13) 2971-2982. 

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