When two or three different columns (non linear type) are connected in series, it is difficult to obtain a complete linear calibration curve. On the other hand, an linear calibration curve can be obtained, when the same linear type columns are connected in series. The above table shows the mean error (%) for each combination of columns. The calibration curves were determined by the method of least squares with cubic equations. The mean error (%) was obtained by taking the average of the errors in molecular weight compared to molecular weight read from the calibration curves with actual molecular weights of the six polystyrene standards. Connection of three linear type column, GPC KF-806L gave the smallest error.
Sample : PS,Polystyrene
Combination of Column |
Mean % Error in M |
Correlation Coefficient |
---|---|---|
KF-805 + KF-804
|
14.68 | 0.9996 |
KF-806 + KF-803
|
6.79 | 0.9999 |
KF-806 + KF-804
|
11.47 | 0.9997 |
KF-806 + KF-805
+ KF-803 |
4.38 | 0.9999 |
KF-806L x 3
|
2.54 | 1.0000 |
Columns : Shodex GPC KF-806 + KF-805 + KF-803, KF-806L x 3 (8.0mmID*300mm each)
Eluent : THF
Flow rate : 1.0mL/min