Capacity ratio factor

Equation (16) was first developed by Purnell [3] in 1959 and is extremely important. It can be used to calculate the efficiency required to separate a given pair of solutes from the capacity factor of the first eluted peak and their separation ratio. It is particularly important in the theory and practice of column design. In the particular derivation given here, the resolution is referenced to (Ra) the capacity ratio of the first... 

The curves show that the peak capacity increases with the column efficiency, which is much as one would expect, however the major factor that influences peak capacity is clearly the capacity ratio of the last eluted peak. It follows that any aspect of the chromatographic system that might limit the value of (k ) for the last peak will also limit the peak capacity. Davis and Giddings [15] have pointed out that the theoretical peak capacity is an exaggerated value of the true peak capacity. They claim that the individual (k ) values for each solute in a realistic multi-component mixture will have a statistically irregular distribution. As they very adroitly point out, the solutes in a real sample do not array themselves conveniently along the chromatogram four standard deviations apart to provide the maximum peak capacity. 

Cows and calves fed low-zinc diets of 25 mg Zn/kg ration showed a decrease in plasma zinc from 1.02 mg/L at start to 0.66 mg/L at day 90 cows fed 65 mg Zn/kg diet had a significantly elevated (1.5 mg Zn/L) plasma zinc level and increased blood urea and plasma proteins (Ram-achandra and Prasad 1989). Biomarkers used to identify zinc deficiency in bovines include zinc concentrations in plasma, unsaturated zinc-binding capacity, ratio of copper to zinc in plasma, and zinc concentrations in other blood factors indirect biomarkers include enzyme activities, red cell uptake, and metallothionein content in plasma and liver (Binnerts 1989). 

The gas expansion factor Yg in Equation 4-68 depends only on the heat capacity ratio of the gas y and the frictional elements in the flow path 2 K. An equation for the gas expansion factor for choked flow is obtained by equating Equation 4-68 to Equation 4-66 and solving for Yg. The result is... 

The calculation to determine the expansion factor can be completed once y and the frictional loss terms 2 Kf are specified. This computation can be done once and for all with the results shown in Figures 4-13 and 4-14. As shown in Figure 4-13, the pressure ratio ( f - P2)/Pi is a weak function of the heat capacity ratio y. The expansion factor Yg has little dependence on y, with the value of Yg varying by less than 1 % from the value at y = 1.4 over the range from y = 1.2 to y = 1.67. Figure 4-14 shows the expansion factor for y = 1.4. 

It is seen that the maximum value of the capacity factor Is inversely proportional to the detector sensitivity or, the minimum detectable concentration. It follows, that the detector sensitivity also sets an ultimate limit on the peak capacity that can be realized from a column. This limit however is fairly high as can be seen from the data given in Table (1) The capacity ratios and peak capacities were calculated for a column having an efficiency of 10,000 theoretical plates, a dead volume of 6.7 ml and a sample concentration of % v/v. 

Capacity factor is also called retention factor, capacity ratio, or partition ratio and is frequently written as k instead of 1C. 

A silica gel with a higher surface area gives a higher capacity ratio, as demonstrated by the determination of famotidine [3] in the presence of its potential degradants and preservatives. The capacity factor increased by more than a factor of 3 when the silica surface area increased from 200 to 350 m7g. 

METHOD E POWER FACTOR APPLIED TO PLANT-CAPACITY RATIO. This method for study or order-of-magnitude estimates relates the fixed-capital investment of a new process plant to the fixed-capital investment of similar previously constructed plants by an exponential power ratio. That is, for certain similar process plant configurations, the fixed-capital investment of the new facility is equal to the fixed-capital investment of the constructed facility C multiplied by the ratio R, defined as the capacity of the new facility divided by the capacity of the old, raised to a power x. This power has been found to average between 0.6 and 0.7 for many process facilities. Table 19 gives the capacity power factor (x) for various kinds of processing plants. 

Chromatographic Retention The retention of a drug with a given packing material and eluent can be expressed as a retention time or retention volume but both of these are dependent on flow rate, column length, and column diameter. The retention is best described as a column capacity ratio (k ) which is independent of these factors. The column capacity ratio of a compound (A) is defined by... 

The LFER-based retention parameter in high-performance liquid chromatography (HPLC) is the logarithm of the phase capacity ratio or retention factor k. The capacity... 

Product or process Process remarks Topical plant size, 1000 tons / yr Fixed- capital investment, million of fixed- capital investment per annual ton of product Power factor (x)t for plant- capacity ratio... 

Capacity factor (k J. The fundamental dimensionless measure of retention in liquid chromatography is the capacity ratio (or capacity factor) (k ), which is defined as the ratio of the number of molecules of solute in the stationary phase, N, to the number of molecules in the mobile phase,... 

INFLUENCE OF DHP CONCENTRATION IN THE PRESENCE OF DEA IN THE ELUENT ON THE CAPACITY RATIOS (k ) AND SELECTIVITY FACTORS (r.jj) OBTAINED FOR NATIVE AND HYDROGENATED ERGOT PEPTIDE ALKALOIDS6 ... 

Instead of the capacity factor, k, the capacity ratio, ke, which is calculated by Eq. (22), is used in the above equation ... 

Also called phase capacity ratio or retention factor, it is a measure of the degree of retention of a compound in a chromatographic column, as... 

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