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Topic: The best result of same annotation compound with different retention time (Read 435 times) previous topic - next topic

The best result of same annotation compound with different retention time

Hi,
    For LC-MS data, after running MS-DIAL, I got annotation results from AlignResult-*.msdial. I found the same annotation compound with different Average Rt(min) and same Average Mz, so how can I choose the right one? In this situation, all have same Annotation tag (VS1.0) and Total score.
    Hope someone can fix it.

The example:
Alignment_ID  Average_Rt(min)  Average_Mz  Metabolite_name  Adduct_type  Post_curation_result  Fill_%  MS/MS_assigned
108           6.462            149.02376   Maltol           [M+Na]+      .                     0.167   True
109           16.723           149.02376   Maltol           [M+Na]+      .                     0.333   True
110           18.059           149.02376   Maltol           [M+Na]+      .                     1       True
111           24.583           149.02376   Maltol           [M+Na]+      .                     1       True

Re: The best result of same annotation compound with different retention time

Reply #1 –
You have to go in and make a judgement call on which one is correct. Do you have a standard to compare it against to verify the expected RT? That would help resolve it. Otherwise you can open the data in MS-Dial and take a look to see if you have any representative MS2 to make a judgment call on based on the similarity to a known standard another group produced. Hopefully it's not just the loss of the sodium. Your %Fill for the last two denote that it was found in every sample at those RTs. Not sure if that helps either, but it might be an indicator.

There isn't enough information to go on here, but we could tell you how to better narrow it down with a bit more information.