Question

Two species, A and B, are separated on a 2.00 m long column which has 5.000 x 103 plates when the flow rate is 15.0 mL/min. A species that is non-absorbing and known not to interact with the stationary phase, elutes in 30.0 s. Compound A elutes from the column in 5.00 min and Compound B elutes in 12.00 min.calculate the peak widths (in seconds) for Compounds A and B,

Answer 1

Explanation:

The given data is as follows.

         $t_{m}$ = 30.0 sec,     $t_{r1}$ = 5 min = $5 \times 60 sec$ = 300 sec

         $t_{r2}$ = 12.0 min = $12 \times 60 sec$ = 720 sec

Formula for adjusted retention time is as follows.

      $t'_{r} = t_{r} - t_{m}$

                 = 300 sec - 30.0 sec

                 = 270 sec

   $t'_{r2}$ = 720 sec - 30 sec

                            = 690 sec

Formula for relative retention ($\alpha$) is as follows.

          $\alpha = \frac{t'_{r2}}{t'_{r1}}$

                     = $\frac{690 sec}{270 sec}$

                     = 2.56

Thus, we can conclude that the relative retention is 2.56.