Metrohm 833 IC Liquid Handling Unit - Manual (Page 11)

1.1 Instrument description
833 IC Liquid Handling Unit / Instructions for Use 8.833.1003
3
1.1.3 833 IC Liquid Handling Sample Preparation Unit
As well as the basic instrument, the 833 IC Liquid Handling Unit
includes a reactor block (sample preparation module) that is
connected to the basic instrument and also remotely controlled by IC
Net.
With the cation exchanger built-into the sample preparation module
such inline sample preparation steps as neutralization and cation
separation can be carried out for analyses by ion chromatography.
The sample preparation module contains a total of three units which are
used in rotation for cation exchange, regenerated with acid and rinsed
with water. In order that each new chromatogram is recorded under
comparable conditions a freshly regenerated cation exchanger is
normally used. Switching takes place either automatically by the IC
system or manually. As sulfate could interfere with the subsequent IC
analysis, the cation exchanger of the sample preparation module
usually uses perchloric acid (HClO
4
) instead of sulfuric acid (H
2
SO
4
) for
regeneration.
The 833 IC Liquid Handling Sample Preparation Unit is particularly
suitable for retrofitting a modular IC system for anion analysis for
sample preparation in a simple way. Two typical applications
(neutralization: exchange of e.g. Na + for H + and cation separation:
exchange of e.g. heavy metals for H + ) are described in detail in the
Instructions for Use. Although the cation exchange technique used is
comparable with the principle of suppression of the 833 IC Liquid
Handling Suppressor Unit, the 833 IC Liquid Handling Sample
Preparation Unit is not suitable for chemical suppression after the
separation of anions by ion chromatography.