Solvent Miscibility - Waters 2487 Dual A Operator's Manual

Water
Use water only from a high-quality water purification system. If the water system does not
provide filtered water, filter it through a 0.45-µm membrane filter before use.
Buffers
When you use buffers, dissolve salts first, adjust the pH, then filter to remove insoluble
material.
Tetrahydrofuran (THF)
When using unstabilized THF, ensure that your solvent is fresh. Previously opened bottles
of THF contain peroxide contaminants, which cause baseline drift.
Caution:
taken to dryness.
D.2 Solvent Miscibility
Before you change solvents, refer to
to be used. When you change solvents, be aware that:
• Changes involving two miscible solvents may be made directly. Changes involving
• Temperature affects solvent miscibility. If you are running a high-temperature
D
• Buffers dissolved in water may 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.
205
THF contaminants (peroxides) are potentially explosive if concentrated or
two solvents that are not totally miscible (for example, from chloroform to water),
require an intermediate solvent (such as isopropanol).
application, consider the effect of the higher temperature on solvent solubility.
Table D-1 to determine the miscibility of the solvents