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Exercise II The separation of two compounds A and B is studied by HPLC on a column of type RP-18. The mobile phase is a binary mixture of water and ACN. A linear relationship exists between the log of the retention factor and the % of acetonitrile within the binary mixture (H2O/CH3CN). Two chromatogram were obtained, one in which the mixture of water and ACN was 70/30 v/v, respectively and the other where the same two components were mixed 30/70 v/v. The equations of the straight lines are: 1. Find the composition of the binary phase which leads to the selectivity factor =1 2. Suppose that for each compound the width at half height of the corresponding peak in the chromatogram is the same and the efficiency of the column is not modified following the composition of the mobile phase. For which combination of the binary mixtures mentioned above is the resolution between the two peaks the best? Discuss the practicalities of your choice