I am using a C30 column for carotenoid analysis. I bought the column recently and using it for the first time. When I use the column in LC-MS scan mode, I clearly see the UV-Vis peaks for my standards, but TIC has a lot of noise and I don't see the m/z peaks corresponding to my standards. Instead, I see peaks with a repeating m/z around 14, like a polymer. I used methanol: MTBE ranging from 95:5 to 50:50 as the mobile phase. I washed the column overnight also. Still, I don't see peaks for my standards, but polymer-like peaks. Does anybody have a similar experience? Any suggestions to resolve this issue? Thank you.
When using a C30 column in chromatography, it is common to observe polymer-like peaks. This phenomenon is typically associated with the stationary phase and its interaction with the analytes. Here are some reasons why polymer-like peaks may be observed with a C30 column:
It's important to note that the presence of polymer-like peaks does not necessarily indicate the presence of actual polymers. Other factors, such as column condition, sample composition, and experimental parameters, can also influence the appearance of polymer-like peaks. Additionally, careful interpretation and further analysis, such as additional characterization techniques, are necessary to confirm the presence of polymers if required.
Thank you for sharing your interesting knowledge.
I used a YMC (Waters) carotenoid column and Nomura Chemical's Develosil C30-UG over 10 years ago and had no problems with detection, especially with TIC on a single MS for the standard, although the background noise was a bit noisy.
Maybe it's fine, but you are not using plastic pipettes or conical tubes, are you?Depending on the extraction solvent, there was considerable elution of polymers and their plasticizers.
In this case, noise becomes worse and S/N goes down.
Also, how about the ionization conditions?
It may be better to check if the target carotenoids are ionized properly without passing through a column, but sometimes the ionization did not be good only with MTBE/MeOH, and it was often better to consider volatile salts and ionization conditions.
Ionization was not very good under solvent conditions with more noisy conditions compared to ODS, but quantitation could be achieved.
This is just my experience, and I hope you will consider it as just for your information.
Good luck!
Yasuhiro Nishida
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