Metrohm 820 IC Separation Center - Manual (Page 74)

4 Notes - Maintenance - Faults
819 IC Detector / 820 IC Separation Center
66
4 Notes - Mainte-
nance - Faults
4.1 Practical notes on ion chromatography
4.1.1 Separating columns
The attainable quality of analyses with the 819/820 IC system depends
to a large extent on the separation efficiency of the column used. When
purchasing an IC column you should ensure that the separation effi-
ciency suffices for the analysis problems at hand. Ascertain the char-
acteristic data of the IC column on the standard chromatogram en-
closed with the column such as capacity factors, selectivity, plate num-
ber and resolution and check these data with your own measurements.
If any difficulties arise, you should always first check the quality of the
column by recording a standard chromatogram.
Detailed information about the separating columns available from
Metrohm can be found in the data sheet accompanying your separat-
ing column, in the Metrohm IC Column Catalog, which is available
form your local Metrohm agency, or on the Internet under
http://www.metrohm.com in the ion chromatography product sector. In-
formation about special IC applications can be found in the relevant
"Application Bulletins" or "Application Notes"; these are available
on the Internet under http://www.metrohm.com in the applications sec-
tor, or can be requested free of charge from your local Metrohm
agency.
Protection
To protect the column against foreign particles which could have an
adverse influence on the separation efficiency, we advise you to subject
both the eluents and all samples to microfiltration (0.45 µ m filter) and
to siphon the eluent through the 6.2821.090 Aspirating Filter.
To avoid contamination by abrasive particles arising from piston seals
of the 818 IC Pump, it is advantageous to install an in-line filter be-
tween the pump and the 820 IC Separation Center. The 6.2821.120
Filter unit PEEK 47 (see Section 2.7.3) supplied with the 818 IC Pump
for operation with PEEK capillaries in the pressure range 0 … 30 MPa.
The use of readily interchangeable precolumns serves to protect the
actual separating columns and increase their service life appreciably.
The precolumn that is suitable for your separating column can be found
in the Metrohm IC Column Catalog which is available from your local
Metrohm agency, the data sheet accompanying your separating col-
umn, the product information about separating columns that can be
found under http://www.metrohm.com , ion chromatography products,
or let your agency advise you directly.