Waters Envirogel GPC Cleanup Column - Manual (Page 6)

[ Care and Use ManUal ]
6 Waters Envirogel GPC Cleanup Column
v. Care anD maintenanCe
General care and maintenance procedures are addressed in the Waters GPC Cleanup System Operator’s Guide. Additional symptoms that you
may observe are listed in Table 1. Recalibrate columns after any cleaning procedure.
Table 1. Troubleshooting
Problem Possible Cause Corrective Action
High pressure shutdown Clogged fluid path Change all filters in fluid path. Filter all samples and
solvents before use. Replace all tubing.
Flush column at 2 m by reversing direction of flow through
column.
Replace column.
Low operating pressure Leaks Tighten all fluid connections.
Insufficient solvent Refill solvent reservoir.
Air in-line Purge system.
Retention times too long Pump flow rate set too low Check flow setting and verify output.
Leaks Tighten fluid connections.
Wrong columns Verify length and diameter.
Retention times too short Pump flow rate set too fast Check flow rate setting and verify output.
Data collection device improperly connected Ensure data collection starts at inject signal.
Wrong columns
Verify length and diameter.
No peaks, poor recovery Solvent flow too low Verify pump pressure.
Injector blocked or leaking Check for leaks or blockage.
Detector malfunctioning Check wavelength, sensitivity, signal output cables.
Broad, smeared peaks, or peaks
appear as doublet Rearrangement of packed bed or void in the
column packing Check system performance with each column separately.
Reverse flow through affected column using 2 mL injections
of toluene or xylene at 2 mL/min. If not corrected after 10
injections, replace column.
Blockage or leak in injector sample loop Check for leaks or excessive pressure drop across sample
loop. Back flush loop.
In-line or inlet filter is partially clogged Reverse flow through column and inject 2 mL of
tetrahydrofuran, butylchloride, or a mixture of 1:1
cyclohexane:methylene chloride. Change the inlet filters.
Retention times shift more than
5% Change in flow rate Check flow rate.
Change in laboratory temperature Stabilize laboratory temperature or column temperature.