Baseline drop in HPLC between injections

[iribe90]

Hello all,

I run a Agilent 1100 HPLC, and I been having some issues getting the system to stabilize after it was purchased. One of the issues that I’d like to take right now is baseline drop between injections. The system seems to be stable during the run, but between injections the baseline will drop drastically, and during other injections go back to normal. The áreas u ser the peaks seem to be unaffected, but I’d like to know if there is something wrong with the HPLC, or this is a non issue since the area of the peaks are unaffected.

[Consumer Products Guy]

Add a post-run/equilibration time of 5 additional minutes.

[James_Ball]

I think there is also the option to have the detector do an Auto Zero prior to each run, if that it turned on you could see a change in baseline at injection if the baseline has not returned completely to were it was before.

[pwm]

Could be a pressure variance between your mainpass and bypass positions. Whats your initial back pressure and what is your backpressure while sampling?