title: Validation of the Mass-Extraction-Window for Quantitative Methods Using Liquid Chromatography High Resolution Mass Spectrometry.
abstract: A paradigm shift is underway in the field of quantitative liquid chromatography-mass spectrometry (LC-MS) analysis thanks to the arrival of recent high-resolution mass spectrometers (HRMS). The capability of HRMS to perform sensitive and reliable quantifications of a large variety of analytes in HR-full scan mode is showing that it is now realistic to perform quantitative and qualitative analysis with the same instrument. Moreover, HR-full scan acquisition offers a global view of sample extracts and allows retrospective investigations as virtually all ionized compounds are detected with a high sensitivity. In time, the versatility of HRMS together with the increasing need for relative quantification of hundreds of endogenous metabolites should promote a shift from triple-quadrupole MS to HRMS. However, a current "pitfall" in quantitative LC-HRMS analysis is the lack of HRMS-specific guidance for validated quantitative analyses. Indeed, false positive and false negative HRMS detections are rare, albeit possible, if inadequate parameters are used. Here, we investigated two key parameters for the validation of LC-HRMS quantitative analyses: the mass accuracy (MA) and the mass-extraction-window (MEW) that is used to construct the extracted-ion-chromatograms. We propose MA-parameters, graphs, and equations to calculate rational MEW width for the validation of quantitative LC-HRMS methods. MA measurements were performed on four different LC-HRMS platforms. Experimentally determined MEW values ranged between 5.6 and 16.5 ppm and depended on the HRMS platform, its working environment, the calibration procedure, and the analyte considered. The proposed procedure provides a fit-for-purpose MEW determination and prevents false detections.
authors.affiliation: Neuchâtel Platform of Analytical Chemistry, Institut de Chimie, Université de Neuchâtel , Neuchâtel, Switzerland.
authors.forename: Gaétan
authors.initials: G
authors.lastname: Glauser
authors.affiliation: Quantitative Mass Spectrometry Facility, University Hospital of Lausanne, CHUV , 1011 Lausanne, Switzerland.
authors.forename: Baptiste
authors.initials: B
authors.lastname: Grund
authors.affiliation: Institut de Police Scientifique, University of Lausanne , Batochime, 1015 Lausanne, Switzerland.
authors.forename: Anne-Laure
authors.initials: AL
authors.lastname: Gassner
authors.affiliation: EPFL, Institut of Chemical Sciences and Engineering, Batochime, 1015 Lausanne, Switzerland.
authors.forename: Laure
authors.initials: L
authors.lastname: Menin
authors.affiliation: BioID, Department of Laboratories, University Hospital of Lausanne, CHUV , 1011 Lausanne, Switzerland.
authors.forename: Hugues
authors.initials: H
authors.lastname: Henry
authors.affiliation: Thermo Fisher Scientific , Bremen, Germany.
authors.forename: Maciej
authors.initials: M
authors.lastname: Bromirski
authors.affiliation: Swiss Institute of Bioinformatics, Génopode, University of Lausanne, 1015 Lausanne, Switzerland.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Schütz
authors.affiliation: Quantitative Mass Spectrometry Facility, University Hospital of Lausanne, CHUV , 1011 Lausanne, Switzerland.
authors.forename: Justin
authors.initials: J
authors.lastname: McMullen
authors.affiliation: Quantitative Mass Spectrometry Facility, University Hospital of Lausanne, CHUV , 1011 Lausanne, Switzerland.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Rochat