Packing technique

Finally, we note that the size and shape of the particles of the packing, the packing technique, and column dimensions and configuration are additional factors which influence a GPC experiment. In addition, the flow rate, the sample size, the sample concentration, the solvent, and the temperature must all be optimized. Details concerning these considerations are found in analytical chemistry references, as well as in the technical literature of instrument manufacturers. 

Solution Only the bottom one-foot was hand stacked and the rest of the bed was randomly packed using a wet-packing technique. 

Other diffusion coatings include manganising to produce austenitic or martensitic surface layers on steel. Mixed Mn/Cr diffusion coatings are readily produced by pack techniques. Carbide coatings based on Ti, V and Cr, singly or in combination, are mainly produced for their wear-resisting properties There are now several commercial boronising processes Con-... 

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. 

OUTLINE OF SLURRY PACKING TECHNIQUES FOR RIGID MICROPARTICLES... 

Equation (11) shows that ko increases rapidly with increasing porosity (i/). For columns used in HPLC, e is usually about 0.40 and seems not to depend on the material and the packing technique used for the preparation of the column (22). For e = 0.40 the equation predicts that A — I x I0" in agreement with experimental observations. In order to achieve the very homogeneous packing necessary for a good colunin efUciency, (he... 

This is an example for a case where we have to increase the inlet pressure to reduce analysis time, but we also have to explore ways to improve the column packing technique. A comparison of the results shows that the very well-packed column generates ten times more plates per unit time than the poorly packed column. In Eq. (2 ) r is multiplied by 4 and li is di vided by 2.5. Thus, analysis time and column length are divided by 10 and... 

Let us emphasize that the value given by Eq. (47) is in[Pg.192]

The eluting solvent (n-hexane) is then passed through the column for 10—15 min before the packed column is disconnected. This packing technique was found to be superior to others in terms of ease of operation and cost and requires ca. 15—20 min [13]. 

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