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Messages - superman276

1
MS-DIAL / Re: peak picking
Hi,

I don't think it's just isomers.
Rather large, single peaks are also not getting picked.
This is Thermo RAW data without mzML conversion.
Also, you can see that, in the manual XIC table, you cannot delete entries in the table.
2
MS-DIAL / Re: peak picking
I would say that processing hangs up about 99% of the time. Even with just 1-2 samples.
3
MS-DIAL / Re: peak picking
Hi Hiroshi

I'm not sure that's helping.  But, I haven't been able to try many times because the sample processing keeps hanging (the progress bar just stops mid-way). I'm not sure if anyone else is experiencing that.  I'm using the latest version.
4
MS-DIAL / peak picking
Hello

I can't get the the compounds in the attached picture to peak pick. It's 3 isomers.
The peak picking settings were:  min. peak height = 5000 amplitude;  mass slice width = 0.1 Da
I left most other settings at default.
5
MS-DIAL / mass tolerance
Hello,
Just curious, why are the mass tolerance parameters in Da, rather than ppm?
The ppm difference between 100.000 and 100.001 is 10ppm, and between 300.000 and 300.001 it is 3.33ppm.
However, Agilent qTofs are only able to reach 10-15ppm mass accuracy when acquiring samples in matrix (eg, plasma/urine). A setting of 0.001 Da would be too narrow for 300m/z. I would need 0.003 Da for 10ppm. But, using 0.003 Da for 100m/z would be 30ppm, which is too large.
Perhaps I'm thinking about this incorrectly?
For metabolites such as organic acids, a qtof with a resolution of 10,000 at 120m/z, and 10ppm mass accuracy, what tolerances do I use?