Concordant inter-laboratory derived concentrations of ceramides in human plasma reference materials via authentic standards

In this community effort, we compared measurements between 34 laboratories from 19 countries, utilizing mixtures of labelled authentic synthetic standards, to quantify by mass spectrometry four clinically used ceramide species in the NIST (National Institute of Standards and Technology) human blood plasma Standard Reference Material (SRM) 1950, as well as new suite of candidate plasma reference materials (RM 8231). Participants either utilized a provided validated method (SOP) and/or their method of choice (OTHER). Mean concentration values, and intra- and inter-laboratory coefficients of variation (CV) were calculated using single-point and multi-point calibrations, respectively.

The attached file "ILS-Ceramide-Ring-Trial-Datasets.csv"  and the table below map the lab number (LabNum) used in the manuscript in all plots to the originally assigned submission Id (LabId) used in the anonymized reports containing the peak areas submitted by each lab for their SOP (Standard) and / or OTHER (Preferred) workflow. The table below provides further information on the separation used (LC), the mass analyzer type (QQQ=Triple Quads and Traps, Orbitrap, TOF) and the associated mass analyzer resolution (LowRes, HighRes), and links each LabNum to the corresponding dataset name and Zenodo DOI, if available. In order to retain the anonymity of all participating labs w.r.t. the submitted datasets, only the converted mzML files are provided in the linked submissions. Please note that labs were free to choose whether they wanted to disclose their MS data or not. Thus, missing datasets indicate that the corresponding lab did not provide their raw / mzML data. 

All reports together with the code for analysis and visualization, reproducing the figures in the manuscript, are available under the following doi: https://zenodo.org/doi/10.5281/zenodo.10081970. This links to releases of the following GitHub repository: https://github.com/lifs-tools/ils-ceramide-ring-trial. 

Ring Trial mzML Datasets