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6_26931B ELS2100_2100 Ice Se rvice Manual_vsn2.0_maste r.doc
The PL-ELS 2100/2100 Ice can be operated at sub-ambient temperatures to improve the
detection of semi- volatile compounds. In aqueous solvents, baseline noise may become too
excessive at temperatures <15ƒC. However, for organic solvents, the baseline can be controlled
down to 10ƒC, provided the gas flow is increased to compensate.
Nebuliser Temperature
The nebuliser temperature is the parameter requiring least adjustment. In the majority of cases
the nebuliser temperature is set to the temperature of the chromatography system. However,
increasing this temperature can improve instrument performance by increasing the efficiency of
nebulisation by reducing the viscosity and surface tension of incoming solvent. Setting the
nebuliser temperature too high may result in a deterioration of detector performance due to
solvent boiling in the nebuliser, giving rise to increased noise on the baseline due to spiking
Optimisation Procedure
Set the system at the minimum evaporator and nebuliser temperatures and a gas flow rate of 1.6
SLM. Make an initial injection of the test component and monitor the signal response. With each
subsequent injection increase the nebuliser and evaporator temperatures by 10ƒC whilst reducing
the gas flow rate, until optimum sensitivity is achieved. In some cases, especially for volatile
samples, it has been found that maximizing the nebuliser temperature permits a lower evaporator
temperature and thus an increase in sensitivity