Question

A peak elutes from a column at 33.9 min, with a width at half height of 10.4s. How many theoretical plates does this column have?

Answer 1

212724 plates

Step-by-step explanation:

To solve this problem we use the formula:

N = 5.54 (tr/W₀.₅)²

Where

• N is the number of theoretical plates,

• tr is the retention time (33.9 min)

• and W₀.₅ is the peak width at half height (10.4 s).

We solve for N:

• 10.4 s⇒ 10.4 / 60 = 0.173 min

• N = 5.54 (33.9/0.173)²

• N = 212724 plates