In some cases, you may want to change the relative weights. For example, the default w H is only 12.5 while that of w C 2.8 is 83, reflecting the fact that, in an 'average' sample, a difference in the C 2.8 parameter affects the selectivity of the separation much more than an equivalent difference in the H parameter. The default values describe the relative importance of each parameter in affecting the selectivity of the separation of an 'average' sample.

Default values for the weighting factors are entered automatically below.

The weighting factors account for the fact that the selectivity of separations are more sensitive to differences in some parameters than others. W C 2.8 is the weighting factor for the difference in charge interactions at pH 2.8 W B is the weighting factor for the difference in hydrogen bond basicity W A is the weighting factor for the difference in hydrogen bond acidity W S * is the weighting factor for the difference in steric interactions W H is the weighting factor for the difference in hydrophobicity S * 1 - S * 2 is the difference between the steric parameters of columns 1 and 2Ī 1 - A 2 is the difference between the hydrogen bond acidity parameters of columns 1 and 2ī 1 - B 2 is the difference between the hydrogen bond basicity parameters of columns 1 and 2Ĭ 2.8 1 - C 2.8 1 is the difference between the charge interaction parameters (at pH 2.8) of columns 1 and 2 H 1 - H 2 is the difference between the hydrophobicity parameters of columns 1 and 2 It is calculated according to the following equation: A large F s factor indicates that two columns are very different. A small F s indicates that two columns are very similar. The F s factor describes the similarity of two columns.

Step #2 (optional): Select F s Weighting Factors

A similarity factor, F s, will be calculated for each of the other columns in the database (below). Select a column to compare from the list below. Adjust the pH to determine the C value for all columns in the desired pH environment.

Mac mod analytical