Columns For Gas Chromatography: Performance And Selection

Gas Chromatography (GC) is the most widely used method for separating and analyzing a wide variety of organic compounds and gases. There have been many recent advancements in both packed column and capillary column GC. With numerous options and considerations, selecting the right column can be complicated. This resource provides essential guidance for scientists and technicians, including:

• Methods of choosing both capillary and packed columns
• Selection of dimensions (column length, I.D., film thickness, etc.) and type of column
• Guidelines for proper connections of the column to the injector and detector
• United States Pharmacopeia and National Formulary chromatographic methods
• ASTM, EPA, NIOSH, and OSHA column selection specifications
• Information on the advantages of computer assistance in GC and multidimensional GC
• Comprehensive information on column oven temperature control

Columns for Gas Chromatography: Performance and Selection is a hands-on reference for scientists and technicians using GC.

The late Robert L. Grob, PHD, was Professor Emeritus of Analytical Chemistry at Villanova University and a consultant in analytical and environmental chemistry. He coauthored Environmental Problem-Solving Using Gas and Liquid Chromatography and authored Chromatographic Analysis of the Environment, now in its third edition. Dr. Grob published over 250 research publications and held one patent. He was the recipient of the Stephen Dal Nogare Award in Chromatography, the EAS Award in Separation Science, and numerous other awards.

Acknowledgments.

1 Introduction.

1.1 Evolution of Gas Chromatographic Columns.

1.2 Central Role Played by the Column.

1.3 Justification for Column Selection and Care.

1.4 Literature on Gas Chromatographic Columns.

1.5 Gas Chromatographic Resources on the Internet.

References.

2 Packed Column Gas Chromatography.

2.1 Introduction.

2.2 Solid Supports and Adsorbents.

Supports for Gas–Liquid Chromatography.

Adsorbents for Gas–Solid Chromatography.

2.3 Stationary Phases.

Requirements of a Stationary Phase.

USP Designation of Stationary Phases.

Kovats Retention Index.

McReynolds and Rohrschneider Classifications of Stationary Phases.

Evaluation of Column Operation.

Optimization of Packed Column Separations.

2.4 Column Preparation.

Coating Methods.

Tubing Materials and Dimensions.

Glass Wool Plugs and Column Fittings.

Filling the Column.

Conditioning the Column and Column Care.

2.5 United States Pharmacopeia and National Formulary Chromatographic Methods.

References.

3 Capillary Column Gas Chromatography.

3.1 Introduction.

Significance and Impact of Capillary Gas Chromatography.

Chronology of Achievements in Capillary Gas Chromatography.

Comparison of Packed and Capillary Columns.

3.2 Capillary Column Technology.

Capillary Column Materials.

Fused Silica and Other Glasses.

Extrusion of a Fused-Silica Capillary Column.

Aluminum-Clad Fused-Silica Capillary Columns.

Fused-Silica-Lined Stainless Steel Capillary Columns.

3.3 Preparation of Fused-Silica Capillary Columns.

Silanol Deactivation Procedures.

Static Coating of Capillary Columns.

Capillary Cages.

Test Mixtures for Monitoring Column Performance.

Diagnostic Role Played by Components of Test Mixtures.

3.4 Chromatographic Performance of Capillary Columns.

Golay Equation Versus the van Deemter Expression.

Choice of Carrier Gas.

Measurement of Linear Velocity and Flow Rate.

Effect of Carrier Gas Viscosity on Linear Velocity.

Phase Ratio.

Coating Efficiency.

3.5 Stationary-Phase Selection for Capillary Gas Chromatography.

Requirements.

History.

Comparison of Columns from Manufacturers.

Polysiloxane Phases.

Polyethylene Glycol Phases.

Cross-Linked Versus Chemically Bonded Phase.

Chemical Bonding.

MS-Grade Phases Versus Polysilarylene or Polysilphenylene Phases.

Sol-Gel Stationary Phases.

Phenylpolycarborane–Siloxane Phases.

3.6 Specialty Columns.

EPA Methods.

Chiral Stationary Phases.

Gas–Solid Adsorption Capillary Columns: PLOT Columns.

3.7 Capillary Column Selection.

Practical Considerations of Column Diameter, Film Thickness, and Column Length.

Capillary Columns of 0.53mm i.d.: Megabore Columns.

Correlation of Column Dimensions and Film Thickness with Parameters in the Fundamental Resolution Equation.

Column Selection for Gas Chromatography by Specifications.

3.8 Column Installation and Care.

Carrier Gas Purifiers.

Ferrule Materials and Fittings.

Column Installation.

Column Conditioning.

Column Bleed.

Retention Gap and Guard Columns.

Column Fatigue and Regeneration.

3.9 Special Gas Chromatographic Techniques.

Simulated Distillation.

Multidimensional Gas Chromatography.

Computer Modeling of Stationary Phases.

References.

4 Column Oven Temperature Control.

4.1 Thermal Performance Variables and Electronic Considerations.

4.2 Advantages of Temperature Programming over Isothermal Operation.

4.3 Oven Temperature Profiles for Programmed-Temperature Gas Chromatography.

4.4 Role of Computer Assistance in Optimizing Separations in Gas Chromatography.

DryLab (LC Resources).

ProezGC (Restek Corporation).

GC-SOS (Chem SW).

4.5 Fast or High-Speed Gas Chromatography.

Selectivity Tuning.

Resistively Heated Columns and Column Jackets.

4.6 Subambient Oven Temperature Control.

References.

Selected References.

Appendix A: Guide to Selection of Packed Columns.

Appendix B: Column Selection.

Index.