Column packing down fill

Slurry packing techniques are required for the preparation of efficient columns with rigid particles of less than 20 micrometers in diameter. The same general packing apparatus. Figure 4.8, can be used to pack columns by the balanced-density slurry, liquid slurry, or the viscous slurry techniques. Down-fill slurry packing is the method of choice for small bore columns and packed capillary columns. 

Disturbing zone (TLC) 659 Dosimeters (TLC) 710 Down fill, column packing (LC) 350... 

Chromatography operates on the same principle as extraction, but one phase is held in place while the other moves past it.4-5 Figure 23-5 shows a solution containing solutes A and B placed on top of a column packed with solid particles and filled with solvent. When the outlet is opened, solutes A and B flow down into the column. Fresh solvent is then applied to the top of the column and the mixture is washed down the column by continuous solvent flow. If solute A is more strongly adsorbed than solute B on the solid particles, then solute A spends a smaller fraction of the time Dee in solution. Solute A moves down the column more slowly than solute B and emerges at the bottom after solute B. We have just separated a mixture into its components by chromatography. 

Carefully pack a clean column by first filling with a third column volume of buffer (0.2M sodium phosphate, pH 6 0, containing 0.1M sodium sulfate) Swirl the slurry to resuspend it evenly, and pour it down a glass rod onto the inside wall to fill the column Allow to settle under gravity for 0.5-1 h and to let air bubbles escape (see Note 12)... 

Transfer about a quarter of this slurry to the column (Note (g)) filled with water and gently press small quantities of this slurry down with a glass plunger so that an evenly packed column of the KelF/TBP is formed. Note (h). 

When the gel has settled, fill the column with buffer and carefully insert the upper adaptor. Move the adaptor down to the surface of the packed bed and push it further 1-3 mm into the GPC gel. Avoid air bubbles and let the outlets open to avoid compression of the gel. 

The next step in the pathway is the column. The compression fitting on the inlet end-cap leads to the stainless steel frit at the top of the column. The column itself is a heavy-walled stainless steel tube filled with packing and mobile phase. The outlet end is identical to the inlet. Moving on down the wetted surface, we find 0.01-in tubing leading to the detector flow cell. 

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