IonPac NS1 Manual
Document No. 034024-06
Page 35 of 35
B.4.1 Choosing the Appropriate Cleanup Solution
A. Organic solvents can be used alone if the contamination is nonionic and hydrophobic. The degree of nonpolar character
of the solvent should be increased as the degree of hydrophobicity of the contamination within the range of acceptable
solvents listed in Table 4, HPLC Solvents for Use with IonPac NS1 Columns.
B. Concentrated acid solutions such as 1 to 3 M HCl can be used with compatible organic solvents to remove
contamination that is ionic and organic. The acid suppresses ionization and ion exchange interactions of the
contamination with the resin. The organic solvent then removes the subsequent nonionic and hydrophobic contamination.
See Section B.4 above.
A frequently used cleanup solution is 200 mM HCl in 80% acetonitrile. This solution must be made immediately before
use because the acetonitrile will decompose in the acid solution during long term storage.
C. Regardless of the cleanup solution chosen, use the following cleanup procedure in Section B.6, “Column Cleanup
Procedure,” to clean the IonPac NG1 and IonPac NS1.
B.4.2 Column Cleanup Procedure
A. Prepare a 500 mL solution of the appropriate cleanup solution using the guidelines in Section B.4.1, “Choosing the
Appropriate Cleanup Solution.”
B. Disconnect the Suppressor from the IonPac NS1 analytical column. If your system is configured with both a guard
column and an analytical column, reverse the order of the guard and analytical column in the eluent flow path. Double
check that the eluent flows in the direction designated on each of the column labels. Direct the effluent from the outlet
line of the NG1 Guard Column to a separate waste container.
CAUTION
When cleaning an analytical column and a guard column in series, ensure that the guard column is placed after
the analytical column in the eluent flow path. Contaminants that have accumulated on the guard column can be
eluted onto the analytical column and irreversibly damage it. If in doubt, clean each column separately.
C. Set the pump flow rate to 0.50 mL/min (2-mm systems) or 2.0 mL/min (4-mm systems).
D. Pump the cleanup solution through the column for 60 minutes.
E.
Reconnect the Suppressor to the IonPac NS1 analytical column. Place the guard column in line between the injection
valve and the analytical column if your system was originally configured with a guard column.
H. Equilibrate the column(s) with eluent before resuming normal operation.
