title: Analysis of human plasma metabolites across different liquid chromatography/mass spectrometry platforms: Cross-platform transferable chemical signatures.
abstract: BACKGROUND
  The metabolite profiling of a NIST plasma Standard Reference Material (SRM 1950) on different liquid chromatography/mass spectrometry (LC/MS) platforms showed significant differences. Although these findings suggest caution when interpreting metabolomics results, the degree of overlap of both profiles allowed us to use tandem mass spectral libraries of recurrent spectra to evaluate to what extent these results are transferable across platforms and to develop cross-platform chemical signatures.
  
  
  METHODS
  Non-targeted global metabolite profiles of SRM 1950 were obtained on different LC/MS platforms using reversed-phase chromatography and different chromatographic scales (conventional HPLC, UHPLC and nanoLC). The data processing and the metabolite differential analysis were carried out using publically available (XCMS), proprietary (Mass Profiler Professional) and in-house software (NIST pipeline).
  
  
  RESULTS
  Repeatability and intermediate precision showed that the non-targeted SRM 1950 profiling was highly reproducible when working on the same platform (relative standard deviation (RSD) <2%); however, substantial differences were found in the LC/MS patterns originating on different platforms or even using different chromatographic scales (conventional HPLC, UHPLC and nanoLC) on the same platform. A substantial degree of overlap (common molecular features) was also found. A procedure to generate consistent chemical signatures using tandem mass spectral libraries of recurrent spectra is proposed.
  
  
  CONCLUSIONS
  Different platforms rendered significantly different metabolite profiles, but the results were highly reproducible when working within one platform. Tandem mass spectral libraries of recurrent spectra are proposed to evaluate the degree of transferability of chemical signatures generated on different platforms. Chemical signatures based on our procedure are most likely cross-platform transferable.
authors: Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.
authors: Kelly H
authors: KH
authors: Telu
authors: Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.
authors: Xinjian
authors: X
authors: Yan
authors: Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.
authors: William E
authors: WE
authors: Wallace
authors: Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.
authors: Stephen E
authors: SE
authors: Stein
authors: Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.
authors: Yamil
authors: Y
authors: Simón-Manso
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D056148:Chromatography, Reverse-Phase / Q000379:methods; D006801:Humans; D055442:Metabolome; D055432:Metabolomics / Q000379:methods*; D010949:Plasma / Q000737:chemistry / Q000378:metabolism*; D053719:Tandem Mass Spectrometry / Q000379:methods*