Preparation Checklist; Water; Buffers; Tetrahydrofuran (Thf) - Waters Alliance e2695 Operator's Manual

D.1.4

Preparation checklist

The following solvent preparation guidelines help to ensure stable baselines and good resolution:
• Filter solvents with a 0.45-µm filter.
• Degas the solvent.
• Stir the solvent.
• Keep solvents in a location that is free from drafts and shock.
D.1.5

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.
D.1.6

Buffers

When you use buffers, dissolve salts first, adjust the pH, then filter to remove insoluble material.
D.1.7

Tetrahydrofuran (THF)

When using unstabilized THF, ensure that your solvent is fresh. Previously opened bottles of THF
contain peroxide contaminants, which cause baseline drift.
Warning:
to dryness.
D.1.8

GPC solvents and seal choices

For GPC separations, see the following table for plunger seal and seal wash solution
recommendations. If required, use an intermediate solution to prevent immiscibility or precipitation
problems when you switch between GPC and reversed-phase analytical solvents.
Table D–1: Recommended plunger seal and seal wash solution to be used for
GPC solvents:
GPC solvent
Chloroform
Dimethylsulfoxide (DMSO)
Dimethylacetamide
c
(DMAC)
Hexafluoroisopropanol
d
(HFIP)
Methylene chloride
THF contaminants (peroxides) are potentially explosive if concentrated or taken
With standard seal
Fluoroloy G
(yellow)
Recommended
Recommended
Do not use
Recommended
Recommended
February 27, 2018, 715003794 Rev. C
a
With optional seal
Alliance Clear Seal
(opaque)
Recommended
Recommended
Strongly
recommended
Strongly
recommended
Recommended
Page 224
b
Seal wash
solution
100% methanol
100% methanol
100% methanol
50:50
methanol/water
100% methanol