ver.211201E
SHOWA DENKO K.K. (https://www.shodex.com/)
3
7.2 Column Installation
(1) Connect the column to LC system by following the “flow direction arrow” (
➡
) indicated on the column name
tag. If guard column is used, position the guard column in front (before the inlet) of the analytical column.
(2) Make sure to insert the tubing all the way to the end fitting and secure it with the male nut. It is important that
there is no extra space between the tubing and the column side of the end fitting. Presence of an extra space
will let the sample to spread out and may result in wide peaks.
(3)
Set the initial flow rate at less than 0.5 mL/min and start the system. If using the column at an elevated
temperature, keep a low flow rate until the temperature of the column reaches to the set temperature, and
then gradually increase the flow rate to the desired.
(4)
When replacing the shipping solvent with the eluent, wash the column with the eluent for more than
60 minutes.
Caution!
· Verify that there is no solvent leak. It may cause electronic leakage, rust, and/or chemical
injury.
Attention!
·
Make sure not to let air bubbles enter the column while installing the column. The air
bubbles may damage the column.
· When restarting the system after column installation or after holding the eluent flow, start
the system at less than 0.5 mL/min. A rapid increase in pressure can damage the column.
· If the column was used at an elevated temperature, lower the flow rate to less than 0.5
mL/min at the end of analysis. Then, turn off the column oven, and let the column
temperature return to room temperature before stopping the pump. If the pump was
stopped while the eluent inside the column was still hot, as the eluent temperature
decreases, its volume also decreases. This may result in creating an empty space in the
column and deteriorates the column.
Note
· It is recommended to set the pump limiter to avoid exceeding the maximum pressure.
7.3 Solvent Exchange
When replacing the solvent, start the system at less than 0.5 mL/min. Recommended solvent volume to
introduce at each step is 3 to 5 times of the column volume.
Attention!
· Frequent solvent replacement deteriorates the column, and thus not recommended.
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.
If a guard column is used with the analytical column, first remove the guard column and check the performance
of the analytical column alone. If the problem is solved, most likely the cause is from the guard column. In this
case, clean the guard column.
If the problem is not solved by removing the guard column, clean both guard and analytical columns. Make sure
to clean the guard and the analytical columns separately. 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 0.5 mL/min.