Dionex ASE 100, Руководство оператора

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3 • Operation and Maintenance
Doc. 031842-01 5/02
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method to this number and to return the cursor to the left margin
of the screen.
9. Run the new method three times (with the same cell and sample) and analyze
the extracts.
10. If target analytes are present in extract 2 or 3, make the adjustments listed
below (one at a time) to the method. After each adjustment, repeat the method
and analyze the extract.
a. Raise the temperature. In general, raising the temperature
increases the efficiency of the extraction process. However,
because compounds can degrade at high temperature, it is
advisable to keep the temperature below the maximum allowed
(200 °C). If oxidation is a concern, degas the solvent before use.
b. Run two static/flush cycles. Extending the static time enhances
diffusion of the analytes into the extraction fluid. Separating the
static time into two cycles, instead of using one longer cycle,
allows the introduction of fresh solvent midway through. This
helps maintain a favorable solvent/sample equilibrium for
samples that are heavily loaded or otherwise difficult to extract.
c. Increase the flush volume to allow more solvent to pass through
the sample.
NOTE When using 100 mL cells, it may be necessary to
balance the number of static cycles and flush
volume to prevent the collection bottle from
being overfilled.
11. If analytes still appear in the extract from the second extract, make the
adjustments listed below. When target analytes no longer appear in the extract
from the second extract, the method is complete for this sample type.
a. Run three static/flush cycles.
b. Raise the temperature again.
c. Increase static time.
d. Select a different solvent.