ver.220216E
SHOWA DENKO K.K. (https://www.shodex.com/)
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7.3 Solvent Exchange
(1) When replacing the solvent, start the system at less than 0.5 mL/min.
(2) Check miscibility/solubility of the desired new solvent and the solvent currently filled in the column.
(3) When replacing the current solvent with a solvent with low miscibility/solubility to the current solvent, first
use a solvent that is miscible/soluble to both eluents, and then replace it with the new solvent.
(4) When using a gradient method, changes in the eluent compositions may increase the column backpressure.
Adjust the flow rate and column temperature so that the column backpressure remains below the usable
maximum pressure.
7.4 Column Cleaning
Problems in peak shapes and elution time changes or elevated column pressure etc. are often caused by
insoluble or adsorbing components present in the eluent and reagents being deposited inside the column. These
problems may be resolved by cleaning the column. When washing the column, let the washing solution flow
from the column outlet go directly into the waste container and not let the solution go through the detector.
<Cleaning Method>
(1) Insoluble components that block the column inlet may be removed by reversing the flow direction, i.e.,
introducing the eluent from the column outlet, with flow rate at less than half of the recommended flow rate.
(2) Follow below cleaning steps for adsorbing components. For an efficient cleaning, reverse the flow direction
and use the flow rate at less than 0.5 mL/min. Introduce 5 to 10 times column volume of the washing solvent.
Method 1: Adsorption of ionic compounds
Introduce an eluent with high salt concentration or 10-mM aqueous sodium hydroxide solution.
Method 2: Adsorption of hydrophobic compounds
Introduce a mixture of solvent containing 50-mM eluent (buffer or aqueous salt solution) and 50 % (v/v)
acetonitrile or methanol.
Attention!
· Keeping alkaline solution in the column for a long time will lead to the column deterioration.
Please replace the washing solution with the eluent immediately after cleaning.
8. Column Storage
Remove the column from the system after replacing the in-column solvent with the shipping solvent. Securely
tighten the end caps and store the column at a location with stable temperature (a cool and dark space is
recommended). Refer to section 7.3 Solvent Exchange for how to replace the eluent.
Attention!
· Never allow inside of the column to dry. It can damage the column.
