A chromatogram of a mixture of ethanol, 1-propanol, and a 6 foot column at a flo
ID: 555610 • Letter: A
Question
A chromatogram of a mixture of ethanol, 1-propanol, and a 6 foot column at a flow rate in/min. Calculate the adjusted retention time (t) for etha resolution (R) between the ethanol and propanol peaks, the heiht and butanol, the 1-butanol was obtained with of 30.0 cm3/min. The recorder chart speed was 1.00 nol, propanol, and butanol, the tion (a) of butanol with respect theoretical plate (H) for propanol, and the relative retention (o) ofbuano wate ite of a to ethanol. Compound Distance from injection, in Peak Width, in air ethanol 1-propandol 1-butanol 0.50 1.50 2.25 3.10 0.25 0.30 0.40Explanation / Answer
According to the question,
As we know that,
H= L/N
where,
L= length of column
N = number of theoretical plates
L= 6 foot = 72 inches
N = 5.545 (tR/W)^2
So,
where,
tR= retention time = distance from injection point to propanol peak / chart speed
tR = 2.25 in / 1.00 in min-1 = 2.25 min
Then,
W [propanol] = 0.30 in
Then,
N = 5.545 (2.25/0.30)^2 = 312
= H = L/N
= 72/312 = 0.234