By Jill on Wednesday, August 25, 1999 - 12:41 pm:
Hi I am getting a "humplike" peak in a pure sample of methanol. This peak only shows up around 230nm. I am using a PDA detector, and Waters instruments. Mobile Phase is 55:45 methanol, .0425% Phosphoric acid. column novapak phenyl 100x5mmx4um, flow =.75ml.min
Things I have tried:
1.Injecting mobile phase samples to see if they are contaminated.
2.Flushing column with 100% water for few hours
3.Flushing column with 100% methanol for few hours
4.Changing column to a nova pak C18
5.Preparing new mobile phase
6.Sonicated reservoir inlet filters
7.Clean autosampler syringe with 6N nitric acid
8.Premixed mobile Phase
Pull hair out
Hi I have attached chromatograms showing blank methanols and a sample.
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 DIPeak3299.cdfdipeak3299.cdf (3 k) |
| PeakA2774.cdf peaka2774.cdf (3 k) |
| PeakB2985.cdf peak_b2985.cdf (3 k) |
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