Separation Column; Separating Efficiency - Metrohm 883 Basic IC plus Manual

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4.14

Separation column

4.14.1

Separating efficiency

883 Basic IC plus
If the sample is injected automatically, the rinsing time must be at least
three times the transfer time.
Checking the rinsing time
You can determine if the applied rinsing time is sufficient by measuring the
sample carry-over directly. Proceed as follows to do this:
1 Preparing two samples
Sample A: A typical sample for the application.
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Sample B: Ultrapure water.
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2 Determining "Sample A"
Allow "Sample A" to run through the sample path for the duration of
the rinsing time; inject and then measure it.
3 Determining "Sample B"
Allow "Sample B" to run through the sample path for the duration of
the rinsing time; inject and then measure it.
4 Calculating the sample carry-over
The sample carry-over corresponds to the ratio of the peak areas of
the measurement from Sample B to the measurement from Sample
A. The smaller this ratio, the smaller the amount of sample carry-
over. This ratio can be changed by varying the rinsing time. This can
be used to determine the required rinsing time for the application.
The analysis quality that can be attained depends in a large part on the
separating efficiency of the separation column being used. The separating
efficiency of the selected separation column must be sufficient for the cur-
rent analysis problems. If difficulties arise, start by checking the quality of
the separation column in each case by recording a standard chromato-
gram.
You can find detailed information on the separation columns available
from Metrohm in the leaflet provided along with your separation column,
in the Metrohm IC Column Program (available from your Metrohm
representative) or on the Internet at
Chromatography product area. You can find information on special IC
applications in the corresponding "Application Bulletins" or "Applica-
tion Notes", which are available on the Internet at
4 Operation and maintenance
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