Guidelines for Shodex Column Selection : Synthetic Polymers
The separation by GPCmode assumes that no interaction exists between packing material and sample. This assumption can be realized, if the selected eluent does not generate any interaction. The column and the eluent most suited should be carefully selected considering the sample characteristics such as hydrophilic or hydrophobic, polar or non-polar, ionic or non-ionic, etc.
* : Include K-,KD-,HFIP-,UT- and HT-series.
Measurement results are shown for four kinds of epoxy resins (EPIKOTE 828, 1001, 1004, 1007) with different molecular weights. From the results obtained, it can be concluded that the pore size of a column is an important factor, which should be selected according to the sample molecular weight.
| KF-801 | KF-801 with the smallest pore size can separate EPIKOTE 828 which has the smallest molecular weight. However, this column cannot separate EPIKOTE 1001, 1004 and 1007 well because their molecular weight exceed the exclusion limit of KF-801. |
| KF-802 | KF-802 can separate EPIKOTE 828 and 1001, but it cannot separate EPIKOTE 1004 and 1007 well because the molecular weight is above the exclusion limit. |
| KF-803 | KF-803 can separate all EPIKOTE 828, 1001, 1004 and 1007. However the separation of EPIKOTE 828 is not as good as those of KF-801 and 802 because the pore size of KF-803 is too large for EPIKOTE 828. |
| KF-804 | KF-804 can also separate all EPIKOTE 828, 1001, 1004 and 1007. But none of the separations are as good as those of KF-803 because the pore size of KF-804 is too large for all EPIKOTE. KF-804 is suited for the epoxy resins, whose molecular weight is Larger than EPIKOTE 1007. |
The retio of retention time of Butyl alcohol and Ethylene glycol shows hydrophobicity of column.This figure shows the result that we measured the strength of the hydrophobicity of various columns with water as eluent.
Sample:
Butyl alcohol
Ethylene glycol
Columns : Shodex OHpak SB-802 HQ, SB-802.5 HQ, SB-803 HQ, SB-804 HQ (8.0mmID*300mm each) Shodex Asahipak GS-220 HQ, GS-320 HQ, GS-520 HQ, GF-310 HQ, GF-510 HQ (7.5mmID*300mm each) Eluent : H2O Flow rate : 0.5mL/min Detector : Shodex RI Column temp. : 30deg-C