Chromatography Forum

Is it mandatory to replace D2 lamp and plunger seals, if so,why? What is the effect of plunger seals.

Is it mandatory to replace D2 lamp and plunger seals, if so,why? What is the effect of plunger seals.

D2 lamp will age over time, and the baseline will become noisier, sensitivity/signal-to-noise will be less. However, if your analyte has a large (humongous/ginormous) signal-to-noise, might still be usable.

As to the plunger seals, these prevent mobile phase from leaking out, and are necessary to provide steady pump rate and pressure. Some folks replace these on a set schedule, like once a year; others wait until there are pressure, flow, or leak issues. If one does cGMP work and requires periodic qualification, those parts are typically replaced.

Is it mandatory to replace D2 lamp and plunger seals, if so,why? What is the effect of plunger seals.

Definitely mandatory once they fail. The D2 lamp is normally rated to be turned on for a total of 2000 hours, some will work past 5000 hours but they are not that stable once they have that many hours. If you leave the D2 lamp on constantly remember that 2000 hours is just over 83 days, so it is best to have a way for it to turn off at the end of an analytical run.

When pump seals begin to wear out, they start to shed particles of themselves into the flow path which can begin to clog the system and cause many different problems from high pressure to peak tailing depending on if they simply clog a frit prior to the injector of if they end up on the inlet side of the analytical column.

All analytical instruments are just like a vehicle or other machine, you either do routine maintenance on them or replace them once they fail.

Thank you for providing me the information.