Preparation of columns

Preparation of column. Pack the chromatographic tube in the following order a quartz-wool plug, 1.0 g of silica gel (deactivated with 1.5% water), then a 5-10-mm layer of sodium sulfate. Finally, insert a small amount of quartz-wool on top of the column packing. Before use, rinse the column with 5 mL of n-hexane and discard the eluate. 

Capillary electrochromatography (CEC) is a miniaturized separation technique that combines aspects of both interactive chromatography and capillary electrophoresis. In this chapter, the theory of CEC and the factors affecting separation such as the stationary phase and mobile phase parameters have been discussed. The chapter focuses on the types and preparation of columns for CEC and describes the progress made in the development of open-tubular, particle-packed, and monolithic columns. The detection techniques in CEC such as the traditional UV detection and improvements made in coupling with more sensitive detectors such as mass spectrometry are also described. The chapter provides a summary of some applications of CEC in the analysis of pharmaceuticals and biotechnology products. 

Preparation of columns put 1 ml of DEAE cellulose into a 2-ml column (with a nylon mesh, 40 pm, to retain the cellulose). Equilibrate the column three times with 2 ml of H20. 

Having initially led to the development and expansion of derivatization procedures, the above reasons remain important even nowadays, in spite of the fact that their significance for some compounds has decreased owing to the development of modern procedures for the preparation of columns, deactivation and the preparation of modern chromatographic packings. 

In conclusion, it is necessary to add that a number of the problems mentioned, caused by adsorption in the chromatographic system, may be solved by new technological procedures for the preparation of columns and whole systems. Modern sorbents and procedures for deactivation have partly solved the initial difficulties in some instances, but the field is still wide enough for useful applications of derivatives. 

Fic. 4. Preparation of column packing. Heat treatment-silanization at 370°C. Reproduced from Street (S12) with i>ermission. 

Active immobilized enzyme used in the preparation of columns for the hydrolysis of lactose... 

Preparation of Column—Use Pyrex tubes of 2-cm internal diameter. Soak the prepared alginic acid (4 g 50-100 mesh B.S. per column) in water until swelling is complete (about four hours), then pack in suspension into the tubes previously plugged with cotton wool. Allow the alginic acid to settle and place a second plug on top. Wash the columns... 

The fact that the chromatographic plate is disposable enables us to reduce a series of operations connected with the preparation of columns for HPLC. 

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