Are mass spectra reproducible between labs?
At the ASLO Aquatic Sciences meeting in Victoria, Canada (June, 2018), Dolly Kothawala made a public call for better quality control in mass spectrometry analysis of dissolved organic matter samples. It was a topic that had been on my mind for quite a while, and with more and more labs adding high resolution mass specs to their analytical labs, it seemed to like a perfect time to get a group together to begin the journey of a ring trial.
I met Juliana D'Andrilli at the same meeting, who'd been involved in high resolution mass spectrometry for DOM from the beginning at the Florida Maglab. Between the two of us, we had a pretty good network of contacts to approach, and soon enough we had 17 laboratories on board who agreed to analyse 4 solutions prepared from the IHSS in positive and negative mode ESI with their lab's instrument.
The paper took ages to write! With 40 excellent co-authors with comments to consider, it really was a hard process. The review process was also grueling (and time consuming) - but fair. Eventually it was published almost 2 years after it was conceived, in June 2020.
The results are published in Limnology and Oceanography: Methods. https://aslopubs.onlinelibrary.wiley.com/doi/full/10.1002/lom3.10364
My favourite figure is one showing the common and different formulas found as mass spectra and van Krevelen diagrams for the 4 samples:
There is also a tool for quickly comparing new data to the data from the study, written by the collaborators from the Barrow lab in Warwick: