High School

Calculate the number of theoretical plates for an analyte on a column if the analyte eluted at 25.4 minutes and its width at its base is 1.57 minutes.

Answer :

The number of theoretical plates for the analyte, calculated using the given retention time and peak width at the base, is approximately 264.

To calculate the number of theoretical plates (N) for an analyte on a chromatographic column, we can use the formula:

N = (tR / wb)2

Where tR is the retention time of the analyte and wb is the width of the peak at its base.

In this example, the student has provided a retention time (tR) of 25.4 minutes and a baseline width (wb) of 1.57 minutes. Plugging these values into the formula gives:

N = (25.4 / 1.57)2 = (16.2420382)2 ≈ 263.80

Theoretical plates in chromatography represent a measure of separation efficiency.

Therefore, the number of theoretical plates for the analyte is approximately 264.