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- Posts: 4
- Joined: Tue Dec 04, 2012 10:57 pm
MPA: 80:20 (1.0% TEA Aqueous:ACN)
MPB: 20:80 ((1.0% TEA Aqueous:ACN)
btw, all high quality reagents
Temp. 30C
Detection: 280 nm
Baseline starts out flat during isocratic then proceeds to ramp lower and then remain flat when isocratic again.
Neither ACN nor TEA absorb much at 280 nm so this maybe the "norm" of the UPLC.
I am just perplexed that when I run this same method on an HPLC (with gradient volumes identical), the baseline treads flat during isocratic then proceeds to ramp higher then remain flat again when isocratic again.
I have monitored the pressure on the UPLC and ironically, the baseline has the same shape/pattern. Any correlation?