title: Study of exhaled breath condensate sample preparation for metabolomics analysis by LC-MS/MS in high resolution mode.
abstract: Metabolomic analysis of exhaled breath condensate (EBC) requires an unavoidable sample preparation step because of the low concentration of its components, and potential cleanup for possible interferents. Sample preparation based on protein precipitation (PP), solid-phase extraction (SPE) by hydrophilic and lipophilic sorbents or lyophilization has demonstrated that the analytical sample from the last is largely the best because lyophilization allows reconstitution in a volume as small as required (preconcentration factors up to 80-times with respect to the original sample), thus doubling the number of detected compounds as compared with the other alternatives (47 versus 25). In addition, PP and/or SPE cleanup are unnecessary as no effect from the EBC components removed by these steps appears in the chromatograms. The total 49 EBC compounds tentatively identified and confirmed by MS/MS in this research include amino acids, fatty acids, fatty amides, fatty aldehydes, sphingoid bases, oxoanionic compounds, imidazoles, hydroxy acids and aliphatic acyclic acids.
authors.affiliation: Department of Analytical Chemistry, Annex Marie Curie Building, Campus of Rabanales, University of Córdoba, E-14071 Córdoba, Spain; Institute of Biomedical Research Maimónides (IMIBIC), Reina Sofía Hospital, University of Córdoba, E-14004 Córdoba, Spain.
authors.forename: M A
authors.initials: MA
authors.lastname: Fernández-Peralbo
authors.affiliation: Department of Analytical Chemistry, Annex Marie Curie Building, Campus of Rabanales, University of Córdoba, E-14071 Córdoba, Spain; Institute of Biomedical Research Maimónides (IMIBIC), Reina Sofía Hospital, University of Córdoba, E-14004 Córdoba, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Calderón Santiago
authors.affiliation: Department of Analytical Chemistry, Annex Marie Curie Building, Campus of Rabanales, University of Córdoba, E-14071 Córdoba, Spain; Institute of Biomedical Research Maimónides (IMIBIC), Reina Sofía Hospital, University of Córdoba, E-14004 Córdoba, Spain. Electronic address: q72prcaf@uco.es.
authors.forename: F
authors.initials: F
authors.lastname: Priego-Capote
authors.affiliation: Department of Analytical Chemistry, Annex Marie Curie Building, Campus of Rabanales, University of Córdoba, E-14071 Córdoba, Spain; Institute of Biomedical Research Maimónides (IMIBIC), Reina Sofía Hospital, University of Córdoba, E-14004 Córdoba, Spain. Electronic address: qa1lucam@uco.es.
authors.forename: M D
authors.initials: MD
authors.lastname: Luque de Castro
mesh_terms: D053000:Analytic Sample Preparation Methods / Q000379:methods*; D001944:Breath Tests / Q000379:methods*; D002853:Chromatography, Liquid / Q000379:methods*; D045853:Exhalation; D005612:Freeze Drying; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D055432:Metabolomics / Q000379:methods*; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry / Q000379:methods*
keywords: Exhaled breath condensate; LC–QTOF; Lyophilization; Metabolomics; Sample preparation