Question

What is dead time. Calculate the peak height of R if a sample containing equal m injected into the column and the following information was obtained as given in table: Parameters 6 x 104 M1 cm 3 x 104 M cm1 ε254 peak height 103 mm peak half-width7.6 mm 14.9 mm

Answer 1

The dead time or holdup time of a chromatograph is defined as the time needed for an unretained substance to transit the system from inlet to detector.

Method 1.

Here, ($\epsilon$₂₅₄ * peak height) for R = ($\epsilon$₂₅₄ * peak height) for S

i.e. 6*10⁴ M^-1 cm^-1 * peak height for R = 3*10⁴ M^-1 cm^-1 * 103 mm

i.e. The peak height for R = 51.5 mm

Method 2.

The peak height for R/7.6 mm = 103 mm/14.9 mm

i.e. The peak height for R = (103*7.6/14.9) mm = 52.5 mm