1. Capillary Columns Nicholas H. Snow Department of Chemistry, Seton Hall University, 400 South Orange Avenue, South Orange, NJ 07079 snownich@shu.edu

2. Capillary/Open Tubular Column

3. WCOT - Wall Coated Open Tubular

4. Capillary Column Dimensions

5. Other Types of Capillary Columns

6. Tubing Material Stainless Steel –reactive Glass –can be made inert –difficult to handle Fused Silica –flexible –most inert –most popular

7. Fused Silica Surface Contains 0.1% -OH groups Very inert Uniform chemical surface

8. Fused Silica High tensile strength Flexible Sheath of polyimide Very inert

9. Capillary vs. Packed

10. Packed Column - ECD

11. Capillary Column - ECD

12. Important Column Parameters

13. Column Diameter

14. Column Length

15. Column Length Recommendations

16. Stationary Phase Film Thickness Starting point: 0.25  m Compromise: resolution and capacity Practical operating temperatures Speed or resolution

17. Thick Film Stationary Phase Advantages –increased retention for volatiles –increased capacity Disadvantages –less efficient –higher temperatures –higher bleed

18. Natural Gas

19. Thin Film Stationary Phase Advantages –high efficiency –lower elution temperatures –fast analysis Disadvantages –low capacity –limited trace analysis

20. Thin Film Separation Air Freshener

21. Stationary Phase Requirements Selectivity Low Bleed Rate Reproducibility

22. Common Stationary Phases polysiloxane gum phases

23. Stationary Phases polyglycol

24. Crosslinked Stationary Phases More stable Clean by rinsing Longer lifetimes

25. Carrier Gas Flow Rate

26. Review - Capillary Columns

28. Column Selection