Evaluation of Column Operation

A good gas chromatographic column is considered to have high separation power, high speed of operation, and high capacity. 

One of these factors can be improved usually at the expense of another. Thus, a number of column parameters need to be discussed so that we can arrive at an efficient operation of a column. We now look at several of these and illustrate with appropriate relationships. 

In determining n, we assume that the detector signal changes linearly with concentration. If it does not, then n cannot measure column efficiency precisely. If Equations 2.55 or 2.57 are used to evaluate peaks that are not symmetrical, positive deviations of 10-20% may result. Since n depends on column operating conditions, these should be stated when efficiency is determined. 

TABLE 2.8 CALCULATION OF COLUMN EFFICIENCY FROM CHROMATOGRAMS 

Standard Deviation Terms Measurements Plate Number n= 

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