Spiky Peak Tops But Flat Baseline; Large Baseline Offset - Agilent Technologies 1290 Infinity II User Manual

7
Troubleshooting and Diagnostics
General Problems

Spiky peak tops but flat baseline

Probable cause
1
2
3
4
5
6

Large Baseline offset

Probable cause
1
2
3
4
78
Inconsistent nebulization
Incorrect gas being used
Poor regulation of inlet gases
Insufficient smoothing
Sample precipitation during nebulization
Inconsistent pump flow rates
Inefficient evaporation
High concentration of non-volatile buffer or
stabiliser
Contaminated diffuser
Optics Heater failed
Suggested actions
Nitrogen is the recommended gas - others can be
used but may not nebulize as efficiently
Change gas to nitrogen or evaluate different
nitrogen sources
• If using bottled gas, check that gas regulator
is functioning correctly and giving consistent
flow
• Alternatively, use a pulse dampener
The broader the peaks, the higher the smoothing
value is required. Increase smoothing to 50 for
Flash separations
• Reduce sample concentration or inject same
loading in larger volume
• Check sample solubility in mobile phase
eluents
See remedy for pump pulsation in the baseline
noise section
Suggested actions
Increase the evaporator temperature and/or gas
flow
Use a lower concentration of stabiliser,
unstabilised solvent or a more volatile buffer
(ammonium acetate or ammonium formate)
Perform cleaning procedure
Refer to local distributor or Agilent Technologies
Agilent 1290 Infinity II ELSD User Manual