1. Intro to Chromatography CHM 480 Suroviec
Chapter 26
Intro to Chromatography
CHM 480
Suroviec

2. I. Classification of Chromatographic Methods
Method for separating components of a mixtures based on their relative affinities for 2 different phases

3. Resolution of Gaussian peaks of equal area and amplitude
Resolution of Gaussian peaks of equal area and amplitude. Dashed lines show individual peaks, and solid lines are the sum of two peaks. Overlapping area is shaded.

4. II Migration Rates of Solutes
A. Distribution constants

5. B. Retention Time

6. II. Migration Rates of Solutes

7. A. Relating retention time

8. B. Retention factor

9. C. Relative migration rates
We want the peaks to be base-line resolved.

10. III. Zone broadening Ideal peak shape is gaussian
Variables: number of phase transfers, residence time in phases

11. A. Plate theory

12. B. Rate Theory
Explains why peaks broaden consider solute band moving though the column

13. C. Van deemter Equation
A = multiple flow paths

14. B/u = longitudinal diffusion
Solute continuously diffuses away from the concentrated center of its zone

15. Csu + Cmu = mass transfer coefficient
The slower the linear flow the more complete the equilibration and the less the zone broadening

16. Application of the van Deemter eqn. to gas chromatography

17. IV. Optimizing Performance
Reduce zone broadening
Alter relative migration rates

18. A. Resolution
Calculate efficiency needed for required resolution

19. B. Ways to increase performance
1. Increase N
2. Change k’ 3. Change selectivity factor

20. C. General elution problem