High performance capillary electrophoresis small molecules

High performance capillary electrophoresis in its current form is a new technique. Its feasibility has been proven by the analysis and separation of small ions, drugs, chiral molecules, polymers, and biopolymers.93 We are learning more every day about the small tricks of the trade of the technique, and the efficiency and reproducibility of the methods are improving. 

Smyth WE, Brooks P. 2004. A critical evaluation of high performance liquid chromatography ionization-mass spectrometry and capillary electrophoresis-electrospray-mass spectrometry for the detection and determination of small molecules of significance in clinical and forensic science. Electrophoresis 25 1413. 

The performance of capillary electrophoresis, for the separation of biopolymers, is comparable to or better than that of HPLC. The basis for separation relies on the choice of an appropriate buffer to be adapted to the analysis. Although reproducibility is more difficult to control, mass sensitivity is relatively high a few thousand molecules can be detected. Sample quantity is very small and solvent and reagent consumption during an analysis is negligible (Fig. 8.10). 

There are several good reasons why CE has not captured the lion s share of small-molecule separations. High-performance liquid chromatography (HPLC) has a 23-year head start over capillary electrophoresis, and most of the problems have been worked out. HPLC is rugged, sensitive, scales up to preparative and commercial modes, and scales down to the capillary format. Poorly developed CE methods by ill-trained chromatographers are another contributing factor to the slow acceptance of CE in the world of small molecules. 

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