Skip to main content

Show Posts

This section allows you to view all Show Posts made by this member. Note that you can only see Show Posts made in areas you currently have access to.

Messages - bmondal

4
MS-DIAL / GC-TOF data processing in MSDIAL and redundancies in features identification
Hello,

We collected metabolomics data using an Agilent GC coupled to a LECO HRT+ TOFMS. We then exported the data as netCDF, converted to .ABF format, and processed in MS-DIAL 4.70. We used a FAME mix to set the Retention Index to aid in peak identification. We were able to obtain library-matched features, but after checking the alignment table, we found redundancies of features identified. That is, the redundant features have the same retention time, same quant mass and are consecutively repeated 3 to 4 times. Additionally, some features have slight differences in retention times (~0.01 minutes) and quant masses but identified as the same metabolite. Reviewing the XIC's for such features shows these are unlikely to be different molecules but poorly aligned. I've attached a snapshot of the alignment table to illustrate what we're seeing. This is the first time we are using MSDIAL to process a large dataset from this LECO HRT+ instrument (we have used it in the past with single quad GC-MS & extensively with LC-MS data without such issues). We suspect a setting in the identification and/or alignment windows to be the culprit of the redundancies, but would appreciate some guidance and suggestions as to how to solve this issue.

Many thanks in advance. We're happy to share our specific processing settings if that would be helpful.

Banani