Before you change solvents, consult this table to determine solvent miscibility.
Be aware of the following effects and considerations:
- Temperature affects solvent miscibility. If you are running a high-temperature application, consider the effect of the higher temperature on solvent solubility.
- Buffers dissolved in water can precipitate when mixed with organic solvents.
- You can make changes involving two miscible solvents directly. Changes involving two solvents that are not totally miscible (for example, from chloroform to water) require an intermediate solvent like n-propanol.
- When you switch from a strong buffer to an organic solvent, thoroughly flush the system with distilled water before you add the organic solvent.
Note: λ cutoff is the wavelength at which the absorbance of the solvent equals 1 AU.
Table 1.
Solvent miscibility
| Solvent |
Polarity index |
Viscosity cP, 20 °C (at 1 atm) |
Boiling point °C (at 1 atm) |
Miscibility number (M) |
λ cutoff (nm) |
| ACN |
6.2 |
0.37 |
81.6 |
11, 17 |
190 |
| Acetic acid |
6.2 |
1.26 |
117.9 |
14 |
n/a |
| Acetone |
5.4 |
0.32 |
56.3 |
15, 17 |
330 |
| Benzyl alcohol |
5.5 |
5.80 |
205.5 |
13 |
n/a |
| DMF |
6.4 |
0.90 |
153.0 |
12 |
n/a |
| DMSO |
6.5 |
2.24 |
189.0 |
9 |
n/a |
| Ethanol |
5.2 |
1.20 |
78.3 |
14 |
210 |
| n-Hexane |
0.0 |
0.313 |
68.7 |
29 |
n/a |
| MeOH |
6.6 |
0.60 |
64.7 |
12 |
210 |
| Methoxyethanol |
5.7 |
1.72 |
124.6 |
13 |
n/a |
| 1-Propanol |
4.3 |
2.30 |
97.2 |
15 |
210 |
| 2-Propanol |
4.3 |
2.35 |
117.7 |
15 |
n/a |
| THF |
4.2 |
0.55 |
66.0 |
17 |
220 |
| Triethylamine |
1.8 |
0.38 |
89.5 |
26 |
n/a |
| Water |
9.0 |
1.00 |
100.0 |
n/a |
n/a |
Contents
Solvent considerations
