title: EIder: A compound identification tool for gas chromatography mass spectrometry data.
abstract: We report software entitled EIder (EI mass spectrum identifier) that provides users with eight literature reported spectrum matching algorithms for compound identification from gas chromatography mass spectrometry (GC-MS) data. EIder calculates retention index according to experimental conditions categorized by column class, column type and data type, where 9 empirical distribution functions of the absolute retention index deviation to its mean value were constructed using the National Institute of Standards and Technology (NIST) 2011 retention index database to improve the accuracy of compound identification. EIder filters compound candidates based on elementary composition and derivatization reagent, and automatically adds the molecular information of the native compound to each derivatized compound using a manually created database. When multiple samples are analyzed together, EIder performs cross-sample alignment and provides an option of using an average mass spectrum for compound identification. Furthermore, a suite of graphical user interfaces are implemented in EIder to allow users to both manually and automatically modify the identification results using experimental information at various analysis stages. Analysis of three types of GC-MS datasets indicates that the developed EIder software can improve the accuracy of compound identification.
authors.affiliation: Department of Chemistry, University of Louisville, Louisville, KY 40208, USA; Center for Regulatory and Environmental Analytical Metabolomics, University of Louisville, Louisville, KY 40208, USA.
authors.forename: Imhoi
authors.initials: I
authors.lastname: Koo
authors.affiliation: Biostatistics Core, Karmanos Cancer Institute, Department of Oncology, School of Medicine, Wayne State University, Detroit, MI 48201, USA.
authors.forename: Seongho
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Chemistry, University of Louisville, Louisville, KY 40208, USA; Center for Regulatory and Environmental Analytical Metabolomics, University of Louisville, Louisville, KY 40208, USA.
authors.forename: Biyun
authors.initials: B
authors.lastname: Shi
authors.affiliation: Institute of Molecular Cardiology, University of Louisville, Louisville, KY 40208, USA; Diabetes and Obesity Center,University of Louisville, Louisville, KY 40208, USA.
authors.forename: Pawel
authors.initials: P
authors.lastname: Lorkiewicz
authors.affiliation: Department of Medicine, University of Louisville, Louisville, KY 40208, USA.
authors.forename: Ming
authors.initials: M
authors.lastname: Song
authors.affiliation: Diabetes and Obesity Center,University of Louisville, Louisville, KY 40208, USA; Department of Medicine, University of Louisville, Louisville, KY 40208, USA; Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40208, USA; Robley Rex Louisville VAMC, Louisville, KY 40208, USA.
authors.forename: Craig
authors.initials: C
authors.lastname: McClain
authors.affiliation: Department of Chemistry, University of Louisville, Louisville, KY 40208, USA; Center for Regulatory and Environmental Analytical Metabolomics, University of Louisville, Louisville, KY 40208, USA; Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40208, USA. Electronic address: xiang.zhang@louisville.edu.
authors.forename: Xiang
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000465:Algorithms; D016208:Databases, Factual; D008401:Gas Chromatography-Mass Spectrometry / Q000295:instrumentation* / Q000379:methods; D012984:Software
keywords: Compound identification; GC–MS; Metabolomics; Retention index