Capillary Columns - PowerPoint PPT Presentation

About This Presentation
Title:

Capillary Columns

Description:

Capillary/Open Tubular Column. WCOT - Wall Coated Open ... lower elution temperatures. fast analysis. Disadvantages. low capacity. limited trace analysis ... – PowerPoint PPT presentation

Number of Views:373
Avg rating:3.0/5.0
Slides: 29
Provided by: University482
Learn more at: http://pirate.shu.edu
Category:

less

Transcript and Presenter's Notes

Title: Capillary Columns


1
Capillary Columns
  • Nicholas H. Snow
  • Department of Chemistry, Seton Hall University,
    400 South Orange Avenue, South Orange, NJ 07079
  • snownich_at_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 0.25mm
  • 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 SeparationAir Freshener
21
Stationary Phase Requirements
  • Selectivity
  • Low Bleed Rate
  • Reproducibility

22
Common Stationary Phasespolysiloxane gum phases
23
Stationary Phasespolyglycol
24
Crosslinked Stationary Phases
  • More stable
  • Clean by rinsing
  • Longer lifetimes

25
Carrier Gas Flow Rate
26
Review - Capillary Columns
27
Review - Capillary Columns
28
Column Selection
Write a Comment
User Comments (0)
About PowerShow.com