Solvent Miscibility - Waters ACQUITY Arc System System Manual

Table B–1: Properties of common solvents (continued)
Solvent
Tetrahydrofuran
Toluene
1,2,4-Trichlorobenzene
Triethylamine
Trifluoroacetic acid
Water
o-xylene
B.2.1 Solvent miscibility
Before you change solvents, refer to the table below to determine solvent miscibility.
Be aware of these effects:
• Changes involving two miscible solvents can be made directly. Changes involving
two solvents that are not totally miscible (for example, from chloroform to water)
require an intermediate solvent like n-propanol.
• 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, 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 B–2: Solvent miscibility
Polarity Solvent
index
0.0 N-hexane
1.8 Triethylamine
4.2 Tetrahydrofuran (THF) 0.55
4.3 1-propanol
4.3 2-propanol
Vapor pressure mm Hg
(Torr)
142 at 20 °C
28.5 at 20 °C
1 at 20 °C
57 at 25 °C
97.5 at 20 °C
17.54 at 20 °C
6 at 20 °C
Viscosity
cP, 20 °C
(at 1 atm)
0.313
0.38
2.30
2.35
June 12, 2015, 715004747 Rev. A
Page 72
Boiling
point (°C)
66.0
110.62
213.5
89.5
71.8
100.0
144.41
Boiling Miscibility
point °C number
(at 1 (M)
atm)
68.7 29
89.5 26
66.0 17
97.2 15
117.7 15
Flash
point (°C)
-14
4
106
-9
-3
17
λ
cutoff
(nm)
—
—
220
210
—