Solvent Miscibility - Waters ACQUITY UPLC Operator's, Overview And Maintenance Manual

Solvent miscibility

Before you change solvents, refer to the table below to determine the
miscibility of the solvents to be used. When you change solvents, be aware
that
• changes involving two miscible solvents may be made directly. Changes
involving two solvents that are not totally miscible (for example, from
chloroform to water), require an intermediate solvent (such as
isopropanol).
• 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.
When you switch from a strong buffer to an organic solvent, flush the buffer
out of the system with distilled water before you add the organic solvent.
Solvent miscibility
Polarity
index
–0.3
–0.4
0.0
0.0
1.7
1.8
2.2
2.3
2.4
3.0
3.3
3.4
3.7
3.9
100
Solvent
N-decane
Iso-octane
N-hexane
Cyclohexane
Butyl ether
Triethylamine
Isopropyl ether
Toluene
P-xylene
Benzene
Benzyl ether
Methylene chloride
Ethylene chloride
Butyl alcohol
Boiling
Viscosity
point °C
CP, 20 °C
(1 atm)
0.92 174.1
0.50 99.2
0.313 68.7
0.98 80.7
0.70 142.2
0.38 89.5
0.33 68.3
0.59 100.6
0.70 138.0
0.65 80.1
5.33 288.3
0.44 39.8
0.79 83.5
3.00 117.7
Miscibility
λ Cutoff
number
(nm)
(M)
29 ––
29 210
29 ––
28 210
26 ––
26 ––
–– 220
23 285
24 290
21 280
–– ––
20 245
20 ––
––- ––