[appleseed]

Hello!

Im a bit confused about what exactly is the stationary phase and mobile phase. From what I know, adsorption ( which is when the solute is deposited onto surface) involves the solid stationary phase and mobile liquid phase. While partition involves the stationary liquid phase and mobile gas/liquid phase.

by solid stationary phase, does it mean the solid surface where the solute is depositied? or is it acutally the literal meaning of 'phase' like a period of time?
What I dont understand is how can adsorption involve a mobile liquid phase, when things are deposited onto a surface should it stay still?
Also how can a liquid phase be stationary, doesnt water swoosh around?


Thank you!!
all help appreciated 

[Golden_4_Life]

  A stationary phase in GAS Chrom is the actual capillary column. It's interior is coated with very viscous slurry of wax and polysiloxanes.  Solute molecules become dissolved in the phase after they are injected onto the column.  They "sit" there until the column temp becomes energized (heated up) so that it reaches the Vaporization temp of the solute. Then the solute "boils" off the phase and becomes partitioned (dissolved) into the carrier gas (Mobile phase). The the solute is swept toward the Flame ionization Detector---where a Signal is generated that is proportional to the number of carbons in the formula and its molar conc.. The final result is a Peak Area that represents the combined contribution of "carbon number" and "molar concentration".

[Borek]

I think what you are missing is the dynamic adsorption equilibrium underlying the chromatography.

In general and in every chromatography, stationary phase is the one that is not moving, mobile phase is the one that is in motion - be it liquid or gas.

And every chromotography works exactly in the same way - solutes adsorb and desorb all the time (this is the dynamic equilibrium). When adsorbed on the stationary phase, solute stays in place. When desorbed - it moves together with mobile phase. The more time solute spends as adsorbed, the slower it move, the less time it spends as adsorbed, the faster it move.

Technical details will vary depending on the chromatography type, but general model is always the same.