|Title||»||issue with normalization ratio|
|Assigned To||Guest||»||Brendan MacLean|
Skyline Daily v. 184.108.40.20603, Instrument: Thermo QE+.
For all our metabolites (analyzed using polarity switch), we have defined a normalization method: Ratio to surrogate. The ‘normalizer’ is a heavy labelled amino acid.
When working with many samples (40) we have observed that for ONLY some metabolites NO normalized ratio are reported.
We believe we see the following pattern: normalized values are not available for metabolites that only appear in one polarity mode. The Ratio to surrogate is measured in both positive and negative modes.
Using only one raw file (one sample), we cannot reproduce the problem.
We have attached an .csv file with an data example: Look for '02_carnitine' (line #2148 to #2221) as an example of missing normalization but signals in positive mode.
Will be glad to share .sky file
Very best, Justine and henrik