5 notes – maintenance – faults, 1 practical notes on ion chromatography, 1 separating columns – Metrohm 792 Basic IC User Manual

Page 148

5.1 Practical notes on ion chromatography

792 Basic IC

139

Notes – Maintenance – Faults

5.1

Practical notes on ion chromatography

5.1.1 Separating

columns

Separation efficiency

The attainable quality of analyses with the 792 Basic IC depends to a

large extent on the separation efficiency of the column used. When pur-

chasing an IC column you should ensure that the separation efficiency

suffices for the analysis problems at hand. Ascertain the

characteristic

data of the IC column on the standard chromatogram enclosed with

the column such as capacity factors, selectivity, plate number and reso-

lution and check these data with your own measurements. If any diffi-

culties arise, you should always first check the quality of the column by

recording a

standard chromatogram.

You will find additional general tips on handling IC separating columns

in the

8.732.2003 Metrohm Monograph "Ion chromatography" and

in the

8.792.2003 Metrohm Monograph "Practical ion chromatog-

raphy", as well as detailed information on the separating columns

available from Metrohm (see section 6.3.2) in the leaflets supplied and

in the

8.732.2013 "IC Application Notes" folder.

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 Pm 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 high-pressure pump, it is advantageous to install an

in-line filter

between the pump and the injection valve. In the 792 Basic IC a

6.2821.100 Filter unit PEEK is already mounted for this purpose (see

section 2.6.2).
The use of readily interchangeable

precolumns serves to protect the

actual separating columns and increase their service life appreciably.

The precolumns available from Metrohm (see section 6.3.2) are either

actual precolumns or so-called precolumn cartridges that are used to-

gether with the 6.2821.050 Twin cartridge holder or the 6.2828.110 Pre-

column cartridge holder (see section 2.7).