Chapter 23 - Gas Chromatography Flashcards
How does gas chromatography work?
Analyte is injected into a long tubular column and is moved by a carrier gas while adsorbing on column walls. Low adsorbing analyte is detected before high adsorbing analyte.
In gas chromatography, what is the mobile phase called?
A carrier gas
In gas chromatography, what do open tubular columns offer?
- higher resolution
- shorter analysis times
- greater sensitivity
- lower sample capacity
What are the effects of open tubular columns inner diameter on resolution?
The narrower the column, the greater the resolution.
What are the effects of varying the column length in gas chromatography?
A longer column provides a higher resolution.
In gas chromatography, what are the effects of varying the thickness of the stationary phase?
The effect of thickness in stationary phase open tubular columns is that increasing the thickness, increases the retention time and increases resolution of the early - eluting peaks.
What is the Kovats retention index?
A variable that relates the retention times of a solute to the retention times of linear alkanes.
For a linear alkanes it is equal to 100x the carbon number.
In gas chromatography, what is a temperature program?
A temperature program raises the temperature of a column during separation to increase the solute vapour pressure and decease retention times of late eluting components.
