How to perform a solvent changeover procedure on Waters Styragel columns to convert from DMF to NMP - WKB110513

Article number: 110513

OBJECTIVE or GOAL

Convert Styragel columns packed in dimethylformamide (DMF) to N-methyl-2-pyrrolidone (NMP)

Set the column oven to 50–65 °C.
For 7.8 x 300 mm columns, set the pump flow rate to 0.1 mL/min throughout this procedure.
- For 6.0 x 150 mm columns, set the pump flow rate to 0.06 mL/min throughout this procedure.
- For 4.6 x 300 mm columns, set the pump flow rate to 0.03 mL/min throughout this procedure.
If you are running a gradient, program a 95:5 DMF/NMP to 100% NMP gradient over four hours.
- If you are running in Isocratic mode, make separate DMF:NMP solutions in 5% steps from 95:5 DMF/NMP to 100% NMP, and increase NMP strength over four hours.
Flush with 100% NMP for six hours per column. If there are two columns in the column bank, flush for 12 hours. This equates to 10 column volumes per column.
This solvent switch should be performed only once in the column's lifetime.

GPC Columns – Operating Procedures:

Always ramp from 0.1 mL/min to approximately 1 mL/min over five minutes, for 7.8 x 300 mm columns, for example.
Do likewise when ramping down flow rate.
Typical operating flow rates when performing GPC separations on Styragel columns:
- 7.8 x 300 mm columns - 1.0 mL/min
- 6.0 x 150 mm columns - 0.6 mL/min
- 4.6 x 300 mm columns - 0.3 mL/min
When the column is not in use but is kept on a system, keep the flow rate at 0.1 mL/min minimum at all times. Do not power-off the pump.

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