Agilent InfinityLab ELSD User Manual
69
6
Troubleshooting and Diagnostics
General Problems
Spiky peak tops but flat baseline
Large Baseline offset
Probable cause
Suggested actions
1
Inconsistent nebulization
Nitrogen is the recommended gas - others can
be used but may not nebulize as efficiently.
2
Incorrect gas being used
Change gas to nitrogen or evaluate different
nitrogen sources.
3
Poor regulation of inlet gases
•
If using bottled gas, check that gas regulator
is functioning correctly and giving consistent
flow.
•
Alternatively, use a pulse dampener.
4
Insufficient smoothing
The broader the peaks, the higher the smoothing
value is required. Increase smoothing to 50 for
Flash separations.
5
Sample precipitation during nebulization
•
Reduce sample concentration or inject same
loading in larger volume.
•
Check sample solubility in mobile phase
eluents.
6
Inconsistent pump flow rates
See remedy for pump pulsation in the baseline
noise section.
Probable cause
Suggested actions
1
Inefficient evaporation
Increase the evaporator temperature and/or gas
flow.
2
High concentration of nonvolatile buffer or
stabilizer
Use a lower concentration of stabilizer,
unstabilized solvent or, a more volatile buffer
(ammonium acetate or ammonium formate).
3
Contaminated diffuser
Perform cleaning procedure.
4
Optics Heater failed
Refer to local distributor or Agilent Technologies.
