UPSC Combined Geo-Scientist, Mains · 2026 · Mains Paper III

Q3(d). Resolution of two chromatographic peaks

Question

Calculate the resolution of two analytes, whose chromatographic peaks are separated by 4 min with bandwidth of each analyte as 0.5 min.

Rₛ=(2Δ t_R)/(W₁+W₂)=(2(4))/(0.5+0.5)=8.0 (baseline resolution needs ≥1.5).

Rₛ≥1.5 is baseline separation (peak overlap about 0.1%); a value of 8 is far more than needed, so the column length or run time can be cut.

The full model answer

Worked out step by step, as it should go in the answer booklet. The solution sheet follows it.

Rₛ=t_(R2)-t_(R1)12(W₁+W₂)=(4)/(0.5)=8.0

Rₛ≥1.5 is baseline separation (peak overlap about 0.1%); a value of 8 is far more than needed, so the column length or run time can be cut.

CoversresolutionResolution of two chromatographic peaks