Comparison of Calibration Curves: Linear Type and Column Connection

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