Baseline noise

Issue

Baseline noise

Environment

Analytical IC systems with eluent generation (RFIC-EG)

Resolution

If the normal setup of the system with all consumables will not reach over 2000 psi, additional backpressure tubing is required in the flow path between EG degasser and inject valve. 

Analysis

RFIC systems include two different degassing units in their flow path:

• First is active degassing using an internal vacuum pump to provide the pump with gas-free liquid.

• Second is passive degas tubing located after the EGC cartridge to remove electrolysis gas from the eluent. 

This secondary degas tubing can work only with sufficient pressure difference to ambient atmosphere. From that, the eluent pressure after the cartridge needs to be well above 2000 psi (recommendation: 2300 psi). 

This applies only to analytical RFIC. Capillary systems do not need elevated pressure due to the very low eluent flow rate.

Cause

Low system backpressure