Selecting A Needle-Wash Solvent; Suggested Needle Wash Solvents; Adjusting The Seal Pack; To Prime The Needle-Wash Pump - Waters 2690 Quick Start Manual

Selecting a Needle-Wash Solvent

Use a needle-wash solvent based on the sample and mobile phase chemistries, making
sure all solutions/buffers are miscible and soluble.
solvents recommended for use with certain mobile phase conditions. High sample
concentrations may require other needle-wash solvents.
Table 2-1 Suggested Needle Wash Solvents
Chromatographic Condition
Buffered aqueous,
reversed-phase
Non-aqueous, reversed-phase
Normal phase
GPC
Ion exchange

To prime the needle-wash pump:

1. Be sure the needle-wash fluidic lines are properly installed, as described in the
Waters 2690 Separations Module Operator's Guide , Section 2.6.6, Installing Needle
Wash and Plunger Seal Wash Reservoirs.
2. Press the
(Figure
3. Press the
begins. If solvent does not flow out of the waste tube within 30 seconds, press
the Start Again

2.4.3 Adjusting the Seal Pack

Adjust the seal pack whenever:
• You start up the Separations Module for the first time. The Separations Module does
not perform injections and compression checks until the seal pack has been
adjusted.
• A "Compression Check Failed" error appears on the screen
• A "Missing Restrictor" alarm appears during a diagnostic procedure
Diag screen key in the Main screen. The Diagnostics screen appears
2-12).
Prime NdlWsh screen key. The 30-second needle-wash procedure
screen key.
Table 2-1 lists some needle-wash
Needle Wash Solvent
90% H O, 10% MeOH
2
100% MeOH
Mobile phase
Mobile phase
H O
2
Preparing the Separations Module for Operation 27