Thermo Scientific 074114, Руководство оператора

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Dionex PDA Operator’s Manual
84
Doc. 065378-01 1/12
4.12 Peaks Too Large or Small
•
Analog output-related problem
Check the recorder and integrator input voltage. The Dionex PDA provides a
1 volt full-scale output.
Verify that the selected output range (AU full-scale) is appropriate.
•
System-level problem
Verify that the sample volume or concentration is appropriate.
Verify that the rise time (see page 45 ) and data collection rate (see page 46 )
are appropriate to capture the narrowest peak.
Prepare fresh post-column reagent.
Verify that the reagent flow rate is correct.
•
Reference bandwidth too wide
Select a narrower reference bandwidth. The reference bandwidth should not
overlap the sample bandwidth.
4.13 Poor Peak Shape
•
Concentration of standard is too high; column is overloaded
Dilute the standard.
Install a sample loop with a smaller volume.
•
Concentration of standard is too low
Increase the standard concentration.
•
Inappropriate mobile phase
Do not use a mobile phase that absorbs strongly at the peak absorbance
wavelength.
•
Incorrect sample wavelength selected
If little is known about the analytes in the sample, collect spectra over the full
wavelength range (using both lamps). For guidelines to follow when selecting
the sample wavelength, see
page 47 .