Separation methods future trends

The chapter is organized as follows. We firstly describe models which are suitable for audio signal restoration, in particular those which are used in later work. Subsequent sections describe individual restoration problems separately, considering the alternative methods available to the restorer. A concluding section summarizes the work and discusses future trends. 

The individual self-contained volumes will each encompass a closely related field of applications and will demonstrate those methods which have found the widest applications in the area. The emphasis is expected to be on the comparison of published and established methods which have been employed in the application area rather than the details of experimental and novel methods. The volumes will also identify future trends and the potential impact of new technologies and new separation methods. The volumes will therefore provide up-to-date critical surveys of the roles that analytical separations play now and in the future in research, development and production, across the wide range of the fine and heavy chemical industry, pharmaceuticals, health care, food production and the environment. It will not be a laboratory guide but a source book of established and potential methods based on the literature that can be consulted by the reader. 

This chapter describes the theory, methodology, and application of a microfabrication process that uses phase-changing sacrificial layers (PCSLs) as intermediates to protect microchannel features during bonding or hydrogel polymerization. We focus on key process details associated with the fabrication of microchips, and the application of PCSL-formed microfluidic devices in CE separations and other electric field-based analysis methods. Finally, we provide a brief overview of potential future trends and applications of PCSL fabrication methods in microfluidics. 

Future trends in the separation area will include translation of all these methods to microchip format, which promises to lead the next revolution in chemical analysis. MEKC and isotachophoresis, a CE separation technique in a discontinuous buffer system, have already been adapted to microchips and applied to assay herbicides, biogenic amines, and ions. Micro-channels on a chip-like structure are likely to be exploited more frequently in CE after further development of nanotechnology because it results in extremely rapid separations that consume only picoliter sample volumes and introduce the possibility of merging sample preparation and analysis in a single device. 

Recently, the trend is towards final determination methods of sufficient sensitivity to avoid methods of separation and enrichment. Ion exchange and chromatographic methods require much time, besides complete destruction of the organic matrix, which limits their application in the anaiysis of biological materials, and thus are not given here. They might attract future attention, however, in speciation studies. 

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