Question

3) Use the chromatogram to answer the following questions. 7.54 655 bar R = 6.44 280 bar Rs = 5.04 165 bar a) Which column has more theoretical plates? b) Which column has a smaller plate height? c) What is the retention time of the compound with the highest partition coefficient? d) Given the flow rate is constant for columns A-C, explain why the most pressure is needed to obtain a constant flow rate for column A?

Answer 1

a) A . Has more theoretical plates as its retention time is high.

b) C has smaller plate heights as it requires less pressure.

c) By graph it is clear that Retention time of ,compound with highest partition coefficient, is column A which is approximately 2.4.

d) d) More pressure needed because column A has highest retention time so solvent flow rate is very slow.