-
- Posts: 8
- Joined: Mon Feb 29, 2016 5:21 pm
I am facing a big problem with my LC-ESI-QQQ.
I am running a multi-method with ~20 analytes. All of them exhibit linear calibration curves over the working range.
Accidentally I measured 2 samples that were very high in 4 of the analytes.
Since then, the calibration curves for those compounds are "flat" (no slope), i.e., all concentrations give more or less the same signal.
I first thougt of a contamination somewere in the LC-system, as the blanks were a little compromised, however, after cleaning the system, the blanks are clean, still the calibration standards give the same response for any concentration (10 to 70 µg/L).
Can there be a phenomenon such as a memory effect for those ions? all other analytes behave normal...
Did anybody experience this?
Thanks
Georg