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- Posts: 104
- Joined: Sun Sep 13, 2015 7:54 am
Flow 1.0ml/min
Column 100x4.6 3micron Thermofisher ODS-2
If any other parameters may be necessary please let me know.
In a period of just a couple weeks, one peak in the samples we analyze has drastically changed shape. Initially it eluted as two peaks, isomers of each other. Now I get one big glob.
Fortunately, it seems to quantify the same. But even so that doesn't answer the question as to why it looks like this. I have attached a picture of a chromatogram of the standard solution.
One possibility is the standard solution has degraded - but the peak shape is the same in fresh formulated samples from our formulation lab as in my standard solution. Could be the raw material? But did it really go bad in just a matter of weeks to where it impacts the peak shape in such a manner?
I have also tried multiple colums, another identical column as well as a thermofisher hypersil gold C18 column - same problem.
I've tried fresh water and methanol in the mobile phase as well - same problem.
So at this point, while it hasn't impacted my results yet, I think it's a problem that should be solved, and I'm not sure where else I can check. I haven't made any other changes to the system between the two analysis where the peaks look good then poor.
Open to suggestions or ideas.