Summary Separation Sciences

Summary Separation Sciences
Chromatography basics:
4 1+k
√ N req= α −1 ∙ k
∙ Rs
1+ k
α req =1+ Rs ∙ 4 ∙ ∙ √N
k
1 α −1 k
R s= ∙ ∙ ∙ √N
4 α 1+ k
t −t t '
k= R 0= R
t0 to
k2
α=
k1

η∙L
∆ P=ϕ ∙ ∙ u0 =500 (non-porous) or 1000 (porous)non-porous) or 1000 (non-porous) or 1000 (porous)porous) (non-porous) or 1000 (porous)1 bar = 105 Pa)
d 2p
L V 0 π ∙ r 2 ∙ L∙ ε
u= t 0= = (non-porous) or 1000 (porous)u in m/sec; F in m3/sec)
t0 F F
F=π ∙ r 2 ∙u ∙ ε =0.7 for porous silica
B D D
uopt =
√ ∙ ≈5∙
C dp dp

tR 2
N= ( )
σt
W 1 /2=2.35 σ t

√ N ln t end
n c=1+
4 ( )t0

L
N=
H
H=2.5∙ d p
√N ∙ R
√ N 2= R1 s ,1
s ,2
∆ tR
R s=
4σ

H A =A ∙ d p
B∙ D
HB=
u0
d 2p
H C =C ∙ ∙ u0
D

Filtering:
tR
σ column=
√N

,σ 2total=σ 2column +σ 2filter
(n ∙ t samp )2 W 2filter
σ= =
12 12

LC modes:
ln ( k )=ln ( k 0 )−S ∙ φ

, Capillary electrophoresis:
μ=μ a−μeof
L d Lt
μa ( ¿ μeof )=
V ∙tR
L2d
N=
2 D∙ t R
k
μa , analyte =μeof + ∙μ
1+k micelle
 k changes with same factor as conc. in micelles

Open tubular chromatography:
d f Dm
δf =
H
dc D f√
h= 0.7 for k=1
dc
u ∙ dc
v= 5.7 for k=1
Dm
σ V =σ t ∙ F

Detection:
σ 2total=σ 2column +σ 2ext σ 2ext =σ inj
2
 +σ 2tubing +σ 2detector
2ext < 0.1 2total
σ ext < 0.3 σ col
V = 0.3Vdet – Vdet
Vdet < 0.5 column
V inj < 0.5 σ V
2 2 2 t 2r ,i 2
σ t ,tot =σ col + σ ext = + σ ext
N

2 π ∙ d 4c ∙ L
σ V= ∙F
384 D
2 d 2c ∙ t π ∙ d 4c ∙ L
σt= =
96 D 384 D ∙ F
2 2 2 V 2R ,i 2
σ V ,tot =σ col +σ ext = + σ ext
N