Performance Calculations
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- Category: about
- Published on 10 June 2013
- Written by Super User
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Performance Calculations
The performance characteristics are calculated for every column to a high degree of precision using a regularly calibrated computer datastation with fast data acquisition. The critical measurements are made in accordance with the method outlined below. Following computer analysis, if the column meets the required specifications, the test chromatogram must still pass visual examination from an experienced operator before the column can be released for dispatch.
The main criteria for the evaluation of column performance are the number of theoretical plates (N), the test pressure drop (∆P) and the peak asymmetry measured at 10% of the peak height.
The number of theoretical plates can be calculated using the expression,
- a and b correspond to the intervals shown in the above diagram. For a perfectly symmetrical Gaussian peak, the peak symmetry (PS) has a value of one, whereas for tailing peaks it will be greater than one.