ver.211110E
SHOWA DENKO K.K. (https://www.shodex.com/)
4
·
Analytes are retained for very short time when using an ultra-rapid analysis and this makes
their peak shapes sharp. Slow detector response results in broader peaks and this may
lead to bad peak separations than actual. Please optimize the detector response setting
by checking the peak separations. Also, slow data-processor sampling rate results in less
data point collection and this may lead to bad peak shapes. Please set the data-
processor’s sampling rate to obtain more than 20 data points for each peak width.
Note
· It is recommended to set the pump limiter to avoid exceeding the maximum pressure.
7.3 Solvent Exchange
(1) Check miscibility/solubility of the desired new solvent and the solvent currently filled in the column.
(2)
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.
(3) 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.
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>
Follow below cleaning steps for adsorbing components. For an efficient cleaning, use the flow rate less than
0.5 mL/min. Introduce 5 to 10 times column volume of the washing solvent.
Method 1: Adsorption of proteins
Introduce an eluent with high salt concentration (1.0 M) or 0.1 % nonionic surfactants.
Method 2: Adsorption of hydrophobic compounds
Introduce a mixture of solvent containing 50-mM eluent (buffer or aqueous salt solution) and 10 - 20 % (v/v)
acetonitrile.
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.