In a chromatogram, tm is 1.81 minutes and t′r is 8.13 minutes. Calculate the retention factor k. Answer should be rounded to nearest 0.01.
Understanding Retention Factor in Chromatography
The retention factor (k) is approximately 4.49 (rounded to the nearest 0.01).
Retention factor (k) in chromatography is a crucial parameter that helps in understanding the behavior of substances in a column. It is defined as the ratio of the time a substance is retained in the column to the time taken for an unretained substance to pass through the column. The formula to calculate the retention factor is:
k = (t′r - t₀) / (t_m - t₀)
Where:
- t′r: retention time of the solute
- t_m: retention time of the solvent front
- t₀: dead time (considered negligible in this case)
Using the given values:
- tm = 1.81 minutes
- t′r = 8.13 minutes
- t₀ = 0
Plugging these values into the formula:
k = (8.13 - 0) / (1.81 - 0)
k = 8.13 / 1.81
k ≈ 4.49
Therefore, the retention factor (k) is approximately 4.49 (rounded to the nearest 0.01).
Retention factor (k) = 4.49 (rounded to the nearest 0.01)