Question

In a chromatographic analysis of lemon oil a peak for limonene has a retention time of 8.36 min with a baseline width of 0.96 min. y-Terpinene elutes at 9.54 min with a baseline width of 0.64 min. What is the resolution between the two peaks?

• A. 1.48
• B. 0.24
• C. 3.16
• D. 1.56

Hint:

In chromatography, a resolution of \(R_s = 1.5\) is generally considered to represent baseline separation (complete separation) between two peaks. The calculated value of 1.48 indicates a very good, near-complete separation.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Resolution (\(R_s\)) in chromatography is a measure of the degree of separation between two adjacent peaks. A higher resolution value indicates better separation. It is calculated based on the difference in retention times and the widths of the peaks.
Step 2: Key Formula or Approach:
The formula for chromatographic resolution is:
\[ R_s = \frac{2(t_{R2} - t_{R1})}{W_1 + W_2} \] Where:
\(t_{R1}\) and \(t_{R2}\) are the retention times of the two components.
\(W_1\) and \(W_2\) are the baseline widths of the corresponding peaks.
Step 3: Detailed Explanation:
From the problem statement, we have:
For Limonene (Peak 1):
\(t_{R1} = 8.36\) min
\(W_1 = 0.96\) min
For \(\gamma\)-Terpinene (Peak 2):
\(t_{R2} = 9.54\) min
\(W_2 = 0.64\) min
Now, we substitute these values into the resolution formula:
\[ R_s = \frac{2(9.54 - 8.36)}{0.96 + 0.64} \] \[ R_s = \frac{2(1.18)}{1.60} \] \[ R_s = \frac{2.36}{1.60} \] \[ R_s = 1.475 \] Step 4: Final Answer:
The calculated resolution is 1.475. This value is closest to the option (1) 1.48.