title: Pre-processing liquid chromatography/high-resolution mass spectrometry data: extracting pure mass spectra by deconvolution from the invariance of isotopic distribution.
abstract: BACKGROUND
  Mass spectra obtained by deconvolution of liquid chromatography/high-resolution mass spectrometry (LC/HRMS) data can be impaired by non-informative mass-over-charge (m/z) channels. This impairment of mass spectra can have significant negative influence on further post-processing, like quantification and identification.
  
  
  METHODS
  A metric derived from the knowledge of errors in isotopic distribution patterns, and quality of the signal within a pre-defined mass chromatogram block, has been developed to pre-select all informative m/z channels.
  
  
  RESULTS
  This procedure results in the clean-up of deconvoluted mass spectra by maintaining the intensity counts from m/z channels that originate from a specific compound/molecular ion, for example, molecular ion, adducts, (13) C-isotopes, multiply charged ions and removing all m/z channels that are not related to the specific peak. The methodology has been successfully demonstrated for two sets of high-resolution LC/MS data.
  
  
  CONCLUSIONS
  The approach described is therefore thought to be a useful tool in the automatic processing of LC/HRMS data. It clearly shows the advantages compared to other approaches like peak picking and de-isotoping in the sense that all information is retained while non-informative data is removed automatically.
authors.affiliation: TNO Research Group Microbiology & Systems Biology, Zeist, The Netherlands. shaji.krishnan@tno.nl
authors.forename: Shaji
authors.initials: S
authors.lastname: Krishnan
authors.forename: Elwin E R
authors.initials: EE
authors.lastname: Verheij
authors.forename: Richard C
authors.initials: RC
authors.lastname: Bas
authors.forename: Margriet W B
authors.initials: MW
authors.lastname: Hendriks
authors.forename: Thomas
authors.initials: T
authors.lastname: Hankemeier
authors.forename: Uwe
authors.initials: U
authors.lastname: Thissen
authors.forename: Leon
authors.initials: L
authors.lastname: Coulier
mesh_terms: D000465:Algorithms; D000596:Amino Acids / Q000032:analysis / Q000097:blood; D001647:Bile Acids and Salts / Q000032:analysis / Q000097:blood; D002247:Carbon Isotopes / Q000032:analysis; D002853:Chromatography, Liquid / Q000379:methods*; D003903:Deuterium / Q000032:analysis; D019277:Entropy; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*
chemical_list: D000596:Amino Acids; D001647:Bile Acids and Salts; D002247:Carbon Isotopes; D003903:Deuterium