The comparison of Asahipak GF-310 HQ an Aqueous/Organic (multi-solvent use) SEC column) and an ODS column when they were used for the analysis of PEG (polyethylene glycol) is shown here.
When GF-310 HQ is used, the effect of acetonitrile concentration on elution time is rather small and the component of lager molecular weight elutes faster. Please refer to (A).
When an ODS column is used, the effect of acetonitrile concentration on elution time is very large and the component of smaller molecular weight elutes faster. The elution time can be shortened by increasing acetonitrile concentration. Please refer to (B).

When an ODS column is used for the analysis of surfactants, the effect of acetonitrile concentration on elution time is rather large and the component of lager molecular weight elutes faster. The elution time also can be shortened by increasing acetonitrile concentration. Please refer to (C).

From the results, we can say that the ODS column has hydrophobic interaction with both nonylphenyl groups and PEG and GF-310 HQ has hydrophobic interaction only with nonylphenyl groups. This difference is considered to be the cause of the difference in the measurement of POE distribution.


Sample :
(A),(B) PEG
(C) Nonylphenol ethoxylate

Column       : (A) Shodex Asahipak GF-310 HQ (7.5 mm I.D. x 300 mm)
             : (B),(C) ODS column from the other manufacturer
Eluent       : CH3CN/H2O
Flow rate    : (A); 0.6 mL/min (B),(C); 0.8 mL/min
Detector     : (A),(B); RI (C); UV (280 nm)
Column temp. : 30 °C