General Problems; Baseline Noise - Agilent Technologies 1290 Infinity II User Manual

7
Troubleshooting and Diagnostics

General Problems

General Problems

Baseline noise

Probable cause
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2
3
4
5
76
Poor nebulisation
Insufficient evaporation
Non-volatile additive in mobile phase
Pressure difference created inside nebuliser
chamber
Pump pulsations, especially in microbore
applications where low flow rates are used
Suggested actions
Increase the temperature of the nebulizer by
10 °C until the baseline noise decreases
• Increase the temperature of the evaporator
by 10 °C until the baseline noise decreases
• Increase the evaporation gas flow rate
• Decrease the nebulisation temperature
Use a volatile mobile phase
• Ensure that the end of the liquid waste tube
is not immersed in liquid
• Ensure that the exhaust tube at rear of unit
is not blocked, or extraction is too strong
• Use a pulse free pump
• Increase the back pressure on the pump by
fitting a back pressure column between the
pump and the injection valve
• Use a pulse dampener directly after the
pump in the system
Agilent 1290 Infinity II ELSD User Manual