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preface to fifteenth edition

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11.30 SECTION 11<br />

FIGURE 11.2<br />

Band asymmetry.<br />

For reasonable quantitative accuracy, peak maxima must be at least 4 apart. If so, then Rs 1.0,<br />

which corresponds approximately <strong>to</strong> a 3% overlap of peak areas. A value of Rs 1.5 (for 6)<br />

represents essentially complete resolution with only 0.2% overlap of peak areas. These criteria<br />

pertain <strong>to</strong> roughly equal solute concentrations.<br />

The fundamental resolution equation incorporates the terms involving the thermodynamics and<br />

kinetics of the chroma<strong>to</strong>graphic system:<br />

1 1 k L<br />

1/2<br />

Rs <br />

4 <br />

1 k<br />

H<br />

Three separate fac<strong>to</strong>rs affect resolution: (1) a column selectivity fac<strong>to</strong>r that varies with , (2) a<br />

capacity fac<strong>to</strong>r that varies with k (taken usually as k 2 ), and (3) an efficiency fac<strong>to</strong>r that depends on<br />

the theoretical plate number.<br />

FIGURE 11.3<br />

Definition of resolution.

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