title: EasyLCMS: an asynchronous web application for the automated quantification of LC-MS data.
abstract: BACKGROUND
  Downstream applications in metabolomics, as well as mathematical modelling, require data in a quantitative format, which may also necessitate the automated and simultaneous quantification of numerous metabolites. Although numerous applications have been previously developed for metabolomics data handling, automated calibration and calculation of the concentrations in terms of μmol have not been carried out. Moreover, most of the metabolomics applications are designed for GC-MS, and would not be suitable for LC-MS, since in LC, the deviation in the retention time is not linear, which is not taken into account in these applications. Moreover, only a few are web-based applications, which could improve stand-alone software in terms of compatibility, sharing capabilities and hardware requirements, even though a strong bandwidth is required. Furthermore, none of these incorporate asynchronous communication to allow real-time interaction with pre-processed results.
  
  
  RESULTS
  Here, we present EasyLCMS (http://www.easylcms.es/), a new application for automated quantification which was validated using more than 1000 concentration comparisons in real samples with manual operation. The results showed that only 1% of the quantifications presented a relative error higher than 15%. Using clustering analysis, the metabolites with the highest relative error distributions were identified and studied to solve recurrent mistakes.
  
  
  CONCLUSIONS
  EasyLCMS is a new web application designed to quantify numerous metabolites, simultaneously integrating LC distortions and asynchronous web technology to present a visual interface with dynamic interaction which allows checking and correction of LC-MS raw data pre-processing results. Moreover, quantified data obtained with EasyLCMS are fully compatible with numerous downstream applications, as well as for mathematical modelling in the systems biology field.
authors.affiliation: Department of Biochemistry and Molecular Biology B and Immunology, Faculty of Chemistry, University of Murcia, Apdo, Correos 4021, 30100, Murcia, Spain.
authors.forename: Sergio
authors.initials: S
authors.lastname: Fructuoso
authors.forename: Angel
authors.initials: A
authors.lastname: Sevilla
authors.forename: Cristina
authors.initials: C
authors.lastname: Bernal
authors.forename: Ana Belén
authors.initials: AB
authors.lastname: Lozano
authors.forename: José Luis
authors.initials: JL
authors.lastname: Iborra
authors.forename: Manuel
authors.initials: M
authors.lastname: Cánovas
mesh_terms: D057205:Automation, Laboratory; D002138:Calibration; D002460:Cell Line; D002853:Chromatography, Liquid / Q000295:instrumentation / Q000706:statistics & numerical data*; D016000:Cluster Analysis; D003627:Data Interpretation, Statistical; D006801:Humans; D020407:Internet; D013058:Mass Spectrometry / Q000295:instrumentation / Q000706:statistics & numerical data*; D055432:Metabolomics / Q000379:methods*; D012984:Software