High performance liquid chromatography theoretical plates

The complexity of CP mixtures precludes the complete separation of individual congeners using either high performance liquid chromatography (HPLC) or GC. Tomy attempted to resolve a technical SCCP mixture by reverse-phase HPLC using a Ci8-column [42]. Little separation was obtained using this method likely because of the complexity of technical mixtures and the small number of theoretical plates of HPLC columns. 

An efficient packed gas chromatography column will have several thousand theoretical plates, and capillary columns will have in excess of 10,000 theoretical plates. The H value for a 1-m column with 10,000 theoretical plates would be 100 cm/ 10,000 plates = 0.01 cm/plate. In a high-performance liquid chromatography (below), efficiency on the order of 400 theoretical plates per centimeter is typically achieved, and colunms are 10 to 50 cm in length. 

During the last decades the different modes of capillary electrophoresis (CE) have developed into high-performance (HPCE) separation methods, offering a high separation efficiency (lO -lO theoretical plates), high sensitivity (femtomole to zeptomole amounts in nano- to picoliter sample volumes), and short analysis times (typically 5-20 min, in special cases only a few seconds). They are considered as a recognized complement and/or coimterpart of liquid chromatography (LC) and gel electrophoretic methods. 

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