Chromatographic response function chromatography

Different aggregations of objective criteria have been developed for particular analytical methods. Table 4.2 gives examples of objective functions for chromatography and spectroscopy. The objective function for chromatography, the chromatographic response function (CRF) accounts for all m peaks of the chromatogram, the time t for elution of the last peak, the noise, Af , at the measurement point of peak i, and the selectivity of peak separation based on Kaiser s measure for peak separation fig (see Figure 4.5). For optimal separations, the CRF is maximized. 

As important as are the three previously mentioned applications of chromatography (Table 1), it is accurate to observe that the primary use of chromatography is for the purpose of establishing the concentration of a known entity (analyte) in a specific sample. As few chromatographic detection strategies are absolute (i.e., their response function can be derived from first scientific principles), the quantitation process includes the characterization of the response function, where the response function is the mathematical relationship that exists between the concentration of an analyte in a standard and the response that is... 

Because the primary use of chromatography is to establish the concentration of a known entity (analyte) in a specific sample and because few chromatographic detection strategies are absolute (i.e., their response function can... 

The transport approach has been used very early, and most extensively, to calculate the chromatographic response to a given input function (injection condition). This approach is based on the use of an equation of motion. In this method, we search for the mathematical solution of the set of partial differential equations describing the chromatographic process, or rather the differential mass balance of the solute in a slice of column and its kinetics of mass transfer in the column. Various mathematical models have been developed to describe the chromatographic process. The most important of these models are the equilibrium-dispersive (ED) model, the lumped kinetic model, and the general rate model (GRM) of chromatography. We discuss these three models successively. 

Detectors discussed in Chapter 22 respond to solutes as they exit the chromatography column. A chromatogram shows detector response as a function of time (or elution volume) in a chromatographic separation (Figure 21-3). Each peak corresponds to a different substance eluted from the column. Retention time, fp is the time needed after injection for an individual solute to reach the detector. 

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