Metrohm 791 VA Detector - Manual (Page 35)

3.4 Startup
791 VA Detector
29
3.4.3 Measuring procedure
In order to be able to carry out measurements it is essential that the
working electrode has achieved a stable base current (see section
3.4.2). If the value of the base current regains its original value after the
determination then as many determinations as required can be carried
out. Attention should be given to the following points:
1 Carrying out the determination
• Inject the sample solution into the HPLC or IC system.
• Record and evaluate the current curve.
2 Allow ELCD system to run overnight
• If the ELCD system is to be used again on the following day
then the 791 VA Detector should not be switched off over-
night. The working electrode is constantly under the polariza-
tion current and is quickly ready for new measurements.
• The HPLC or IC pump is set to a minimal flow rate and runs
overnight. This means that the base current is stabilized after
only a few minutes.
3 Switching off the ELCD system
• Set commutator 3 on the 791 VA Detector to "Stand-by".
• Unplug working electrode 28.
• Switch off the 791 VA Detector.