Col_Selection

Restek Capillary Column Selection

Some Practical Hints

It's TRUE - the higher column efficiency and separation power of capillary columns offers a tremendous advantage over conventional packed column particularly for complex mixtures often experienced in a wide range of applications; environmental, flavors, petrochemicals, pharmaceuticals, natural products etc

For relatively simple separations perhaps one or two standard capillary columns ie a non-polar
( Rtx-1 or Rtx-5) column plus a polar phase ( Stabilwax ) may suffice.

In practise there are tremendous gains to be had by careful selection of the optimum liquid phase for a particular separation.

Compromises are often needed in Sample capacity (for trace analysis) vs column efficiency, Max operating temperature ( for high boilers), Minimum temperatures (for volatiles), Column bleed.
Column efficiency, Sample Capacity vs Column ID etc etc

All this can drastically effect the analysis time

SO ! How does the chromtographer sort all this out ?
Use Method Development Software eg pro EzGC from Restek which also includes a huge collection of Retention Index ( Thermodynamic ) for a wide range of applications.

This software is remarkable and completely simulates ALL capillary GC column and operational paramaters. AND predicts with high accuracy retention times under ALL conditions
You can measure your own base retention on one column and liquid phase and then predict across different . . .

Column ID
Column lengths
Liquid Phase film thickness
Under different conditions
Carrier gas
Flow control, constant Pressure control, Programmed Pressure control
Atmospheric or vacuum (GC/MS) column outlet
Using Isothermal or Multi-rampTemperature programming
Dual column analysis and the use of guard columns are also simulated

Column Selection (*.pdf) '98 Restek Cat p34-44

How do I know which column to use p . . . 36
Pro ezGC Method Development Sofware. . . p37-38 MORE ( all current pages to date )
Stationary Phase Selectivity p . . . 39-40
Internal Diameter (ID) & Film Thickness Select . . . p41-42
Column Length Select
Column Materials

Column Selection upgrade (*.pdf ) '99 Restek Catalog

NEW Website

Chromalytic Technology - Australian Distributors 'specialising in chromatography'
: GC, HPLC & Fluid Transfer Products; Instrumentation Home : Sections

Restek Capillary Column Selection

Some Practical Hints

SO ! How does the chromtographer sort all this out ?Use Method Development Software eg pro EzGC from Restek which also includes a huge collection of Retention Index ( Thermodynamic ) for a wide range of applications.

Column Selection (*.pdf) '98 Restek Cat p34-44

SO ! How does the chromtographer sort all this out ?
Use Method Development Software eg pro EzGC from Restek which also includes a huge collection of Retention Index ( Thermodynamic ) for a wide range of applications.