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To convert your
solvent system for a particular separation method to another, you can use
'equal solvent strength' data as given in the table below. For
example,
look for the capacity factor of your analyte and then find the appropriate
solvent mixture.
Please use this
form to notify me if you have any more data on equal solvent strength
mixtures for HPLC analysis. |
Mixtures
|
| Equal solvent strength mixtures
for reversed phase chromatography for methanol, acetonitrile and
tetrahydrofuran (THF) and their capacity factor k'. |
|
% MeOH in H2O
|
% MeCN in H2O
|
% THF in H2O
|
relative k'
|
|
0
|
0
|
0
|
100
|
|
10
|
6
|
4
|
40
|
|
20
|
14
|
10
|
16
|
|
30
|
22
|
17
|
6
|
|
40
|
32
|
23
|
2.5
|
|
50
|
40
|
30
|
1
|
|
60
|
50
|
37
|
0.4
|
|
70
|
60
|
45
|
0.2
|
|
80
|
73
|
53
|
0.06
|
|
90
|
86
|
63
|
0.03
|
|
100
|
100
|
72
|
0.01
|
Eluotropic strength
|
Values represented as ranges indicate multiple sources
and the "§" symbol means that these are defined values.
Note that in this table not only eluotropic
strength data on silica or alumina is presented but also for C18 !
For a more detailed list and description on how to use
these data, click here.
|
| Solvent |
 (Al2O3) |
(SiOH) |
(C18) |
P´
|
| Pentane |
§0.00 |
§0.00 |
_ |
0.0 |
| Hexane |
0.00-0.01 |
0.00-0.01 |
_ |
0.1 |
| Iso-octane |
0.01 |
0.01 |
_ |
0.1 |
| Cyclohexane |
0.04 |
0.03 |
_ |
0.2 |
| Carbon tetrachloride |
0.17-0.18 |
0.11 |
_ |
1.6 |
| l-Chlorobutane |
0.26-0.30 |
0.20 |
_ |
1.0 |
| Xylene |
0.26 |
- |
_ |
2.5 |
| Toluene |
0.20-0.30 |
0.22 |
_ |
2.4 |
| Chlorobenzene |
0.30-0.31 |
0.23 |
_ |
2.7 |
| Benzene |
0.32 |
0.25 |
_ |
_ |
| Ethyl ether |
0.38 |
0.38-0.43 |
_ |
2.8 |
| Dichloromethane |
0.36-0.42 |
0.32-0.32 |
_ |
3.1 |
| Chloroform |
0.36-0.40 |
0.26 |
_ |
4.1 |
| 1,2-Dichloroethane |
0.44-0.49 |
- |
_ |
3.5 |
| Methyl ethyl ketone |
0.51 |
- |
_ |
5.7 |
| Acetone |
0.56-0.58 |
0.47-0.53 |
8.8 |
5.1 |
| Dioxane |
0.56-0.61 |
0.49-0.51 |
11.7 |
4.8 |
| 1-Pentanol |
0.61 |
- |
- |
- |
| Tetrahydrofuran |
0.45-0.62 |
0.53 |
3.7 |
4.0 |
| Methyl t-butyl ether |
0.3-0.62 |
0.48 |
- |
2.5 |
| Ethyl acetate |
0.58-0.62 |
0.38-0.48 |
- |
4.4 |
| Dimethyl sulfoxide |
0.62-0.75 |
- |
- |
7.2 |
| Diethylamine |
0.63 |
- |
- |
- |
| Acetonitrile |
0.52-0.65 |
0.50-0.52 |
3.1 |
5.8 |
| 1-Butanol |
0.70 |
- |
- |
3.9 |
| Pyridine |
0.71 |
- |
- |
5.3 |
| 2-Methoxyethanol |
0.74 |
- |
- |
5.5 |
| n-Propyl alcohol |
0.78-0.82 |
- |
10.1 |
4.0 |
| Isopropyl alcohol |
0.78-0.82 |
0.60 |
8.3 |
3.9 |
| Ethanol |
0.88 |
- |
3.1 |
- |
| Methanol |
0.95 |
0.70-0.73 |
§1.0 |
5.1 |
| Ethylene glycol |
1.11 |
- |
- |
- |
| Dimethyl formamide |
- |
- |
7.6 |
6.4 |
| Water |
- |
- |
- |
10.2 |
|