By Anonymous on Tuesday, February 19, 2002 - 07:27 am:
Can anyone tell me why, for some samples with very little chromphore, my baseline at the 210nm rises so dramatically. I cannot stabilize the baseline. For other samples that have an equal chromphore however, my baseline is much better only rising 5% as compared to 50% in the previous sample. Can anyone explain to me what could have an effect on the baseline drift on a LC-MS 1100.
My mobile phase is H2O+0.1%formic acid and Acetonitrile+0.1% formic acid. I run a gradient 2-95% H20+formic in 4 minutes on a
RPC18, 50mm X 2.1mm ID column. I have tried longer columns and they do reduce the baseline drift somewhat but I am very interested to know if I can reduce this drift in my shorter columns. Any imput would be much appreciated.
By Beppe on Tuesday, February 19, 2002 - 08:52 am:
On which signal do you get drift (initially you are speaking of 210 nm and later of LC-MS)?
Is the drift really different or is it only apparent (maybe your system "auto-scales" the chromatogram to the biggest peak) ?
By Anonymous on Wednesday, February 20, 2002 - 01:53 pm:
At 210 nm, you are at the wavelength where many organic (and inorganic) reagents are starting to absorb radiation. In other words, at 210 or 190 nm many things (mobile phase constituents) absorb.
Good question: are you noticing MS drift as well?
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