Chromatographic animations


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The Purnell equation

The following examples illustrates the effects of the different factors in the Purnell equation, chromatographic efficiency (N), selectivity (α) and retention (k). The first example has a sufficient resolution of approximately 1.5. The following examples show the effect of reducing one of the three factors.

Sufficient resolution

The first example has a sufficient resolution of approximately 1.5. k1 is 2 and k2 is 2.6, giving an α of 1.3. The efficiency, N, is appoximately 1000.

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The efficiency, N, reduced to half

This animation illustrates the effect of reducing the chromatographic efficency. The number of plates, N, is reduced from approximately 1000 to approximately 500.

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The difference in retention, k, reduced to half

This example shows the effect of a reduced chromatographic selectivity. k2 is reduced from 2.6 to 2.3, which means that α is reduced to 1.15 from 1.30 in the original conditions.

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the retention, k, of both compounds reduced to half

This example shows the effect of a reduced chromatographic retention. Both retention factors, k are reduced to half compared to the original example. Since the retention factors of both compounds are reduced proportionally α is still 1.30.

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