Column length, influence

In addition, particle size and column length influence the efficiency and speed of enantiomer separations. For preparative applications, it is recommended that one uses particle sizes of 16-20 pm. Spherical stationary phases of these particle... 

The allowable pressure drop influences the choice of the particle size and helps determine the column length. Equations for estimating the pressure drop in packed beds are given in Section 6. 

First, we must realize that many variables exist in any structural design. We can make a list of structural variables such as sizes, lengths of objects, materials, laminae orientations, and so on. those variables all have influence just as column length, moment of inertia, and Young s modulus influence column-buckling loads. The complete list of design variables will be called the vector Xj, and that vector will have N components. That list constitutes the definition of the structural configuration. 

Investigate the influence of the entering gas flow rate and entering concentration on the column length required to obtain 90% removal of MEK. 

The activity of the organisms vM and the value of the mass transfer coefficient are important to the process. Vary these to determine their influence on the column length required. 

Early Results About the Influence of Column Length on Resolution 58... 

This chapter deals with the properties of high-pressure liquid chromatography columns. It is divided into two sections column physics and column chemistry. In the section on column physics, we discuss the properties that influence column performance, such as particle size, column length and column diameter, together with the effect of instrumentation on the quality of a separation. In the section on column chemistry, we examine in depth the surfaces of modern packings, as well as the newer developments such as zirconia-hased packings, hybrid packings or monoliths. We have also included a short section on... 

Fig. 18a and b. Influence of column length. Gradient elution of a protein mixture on RP 8 columns of different length (a = 45x4.6 mm, b = 6.3x4.6 mm d0 = 30 nm). Gradient water/2-propanol, both with addition of 0.1 % TFA gradient rate 4%/ml flow rate 0.25 ml/min. The sample was a mixture of ribonuclease A, insulin, cytochrome C, bovine serum albumin, and ovalbumin (in the order of elution). These components were applied in the ratio 2 2 1.2 2 and totaled 50 pg. UV detection at 280 nm. (From Ref.73) with permission)... 

Fig. 29. Influence of column length on gradient elution of SAN copolymers through iso-octane/THF. Column packing material Polygosil 60-5 silica in both cases, do = 6 nm dP = 5 pm. Upper chromatogram column 55x4.6 mm, lower one column 150x4.6 mm. (The lower chromatogram is from the same run as the dashed line in Fig. 28.) Injection 60 pg in 30 pi THF [124]...

Column length has a significant influence on gel filtration whereas column diameter does not influence the resolution but, does affect the amount of protein that can be loaded. In this instance, column lengths between 30 and 60 cm and diameters between 1 and 3 cm would be suitable. Some columns are supplied with flow adaptors, which eliminate the dead volume above the gel bed. 

Obviously, there are many ways to influence the capacity factors. However, the effects described above are predictable (see section 4.2.3) and in a sense trivial. It is worth noticing at this point that certain parameters do not at all affect the capacity factor and therefore do not at all affect chromatographic selectivity. These parameters include column length, flow rate and the diameter of packed columns. This renders these parameters irrelevant to the selectivity optimization process. In some cases they may be considered as parameters... 

A complete optimization of the process would require an intensive use of numerical tools to investigate the precise influence of the number of columns, number of columns per zone, column length, etc. on an defined economical function. 

To determine the influence of column length upon the number of theoretical plates and upon resolution and to demonstrate the ability of increased resolution through utilization of recycle chromatography. 

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