Molecules gases and

Paper HPLC Partition Ion exchange Partition Adsorption Layer of adsorbent spread on glass plate Different size molecules Gases and volatile liquids... 

It should be noted that detailed studies of vibrational relaxation in the state show that typically many hundred torr of added atomic or small molecule gases and even over 100 torr of larger polyatomics such as cyclohexane are required to completely equilibrate the spectrum. - However, we can define approximately the region of Boltzmann fluorescence as being that above about 10 torr of gas. Only meticulous examination of the emission spectrum reveals further change at higher pressures. 

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