Calculate Capacity factor:

In a 25.0 cm long column, the solvent took 2.35min. to run through whereas two compounds X and Y took 9.87min. and 10.63min. with peak half width 45.6sec. and 53.4 sec., respectively. Calculate

a) Capacity factor for X and Y.

b) Separation factor α .

c) Average number of plates and plate height.

d) Resolution.

Answer:

a)         k´x   = t_RX-t_M/t_M

= 9.87 - 2.35/2.35 = 3.2

k´y   = t_Ry-t_M/t_M

= 10.63 - 2.35/2.35 = 3.52

b)         α =      t_RY-t_M/t_RX-t_M

= 10.63 - 2.35/9.87 - 2.35

= 1.10

c.) N_X = 5.54(t_RX/W_x/2)²

=5.54 (9.87× 60sec/45.6sec)²

=934

N_Y = 5.54(t_Ry/W_y/2)²

=5.54 (10.6× 60sec/53.4sec)²

= 786

NAv =(934 +786)/2

=860

H= L/N_Av

=25/860 =0.029 cm

d.) R=2(t_Ry-t_Rx)/1.699(W_y/2+W_x/2)

= (2(10.63×60-9.87×60)/1.699(45.6+53.4))

=0.54