Influence of Retention Time of PEG by Column Temperature

Poly(vinyl alcohol) gel with different hydrophobicity are packed into Asahipak GF-310 HQ and GS-320 HQ columns. The hydrophobicity of the gel of the two columns is going stronger according to the temperature rising. Such influence is observed stronger with GF-310 than GS-320. Then under using water as the eluent at 50 deg-C, PEG is not eluted according to its molecular weight as shown the figure. In order to avoid such influence of hydrophobicity, it is applicable to make close the hydrophobicity of gel and eluent. For example the addition of organic solvent, such as Methanol, to eluent is in effect.
Please refer to Hydrophobicity of Columns.




Sample :
1. PEG, Poly(ethylene glycol) (MW: 20,000)
2. PEG, Poly(ethylene glycol) (MW: 4,000)
3. PEG, Poly(ethylene glycol) (MW: 1,000)
4. PEG, Poly(ethylene glycol) (MW: 400)
5. EG, Ethylene glycol (MW: 62)

Columns      : Shodex Asahipak GF-310 HQ or GS-320 HQ (7.5mmID*300mm each)
Eluent       : H2O
Flow rate    : 0.5mL/min
Detector     : Shodex RI
Column temp. : 30deg-C or 40deg-C or 50deg-C