Scheme of a gel chromatograph

A typical block scheme of gel chromatographic apparatus is shown in Fig. 4.6.4. The mobile phase flows from the solvent container, C, into degassing unit, D, and through filters, F, reaches the pumping system, P, which transports it via the pulse damper, PD, and the sample injecting system, I, into the column, CO. The effluent from the column enters the detector, DE, and flows through the volumeter, V, into the fraction collector, F. 

The effluent may be returned through the pumping system back to the column by means of the special valve, RV. This procedure is called recycling and its most simple arrangement is distinguished in Fig. 4.6.4 by the dashed line. Recycling procedures will be discussed more in detail in Section 4.6.3.11. 

The wavy line designates the electric circuits the signal from the detector and the volumeter is recorded by the registration instrument, R. 

A fundamental requirement for the efficient operation of a gel chromatographic instrument is that there should be no empty volumes where the sample components, which have already been separated, are again mixed. The equipment employed for the separation of biological materials must resist water and solutions of salts and be inert toward samples that can denaturate and otherwise change. 

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