title: Analyte quantification with comprehensive two-dimensional gas chromatography: assessment of methods for baseline correction, peak delineation, and matrix effect elimination for real samples.
abstract: Comprehensive two-dimensional gas chromatography (GC×GC) is used widely to separate and measure organic chemicals in complex mixtures. However, approaches to quantify analytes in real, complex samples have not been critically assessed. We quantified 7 PAHs in a certified diesel fuel using GC×GC coupled to flame ionization detector (FID), and we quantified 11 target chlorinated hydrocarbons in a lake water extract using GC×GC with electron capture detector (μECD), further confirmed qualitatively by GC×GC with electron capture negative chemical ionization time-of-flight mass spectrometer (ENCI-TOFMS). Target analyte peak volumes were determined using several existing baseline correction algorithms and peak delineation algorithms. Analyte quantifications were conducted using external standards and also using standard additions, enabling us to diagnose matrix effects. We then applied several chemometric tests to these data. We find that the choice of baseline correction algorithm and peak delineation algorithm strongly influence the reproducibility of analyte signal, error of the calibration offset, proportionality of integrated signal response, and accuracy of quantifications. Additionally, the choice of baseline correction and the peak delineation algorithm are essential for correctly discriminating analyte signal from unresolved complex mixture signal, and this is the chief consideration for controlling matrix effects during quantification. The diagnostic approaches presented here provide guidance for analyte quantification using GC×GC.
authors.affiliation: Environmental Chemistry Modeling Laboratory (LMCE), ENAC, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
authors.forename: Saer
authors.initials: S
authors.lastname: Samanipour
authors.affiliation: Environmental Chemistry Modeling Laboratory (LMCE), ENAC, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
authors.forename: Petros
authors.initials: P
authors.lastname: Dimitriou-Christidis
authors.affiliation: Environmental Chemistry Modeling Laboratory (LMCE), ENAC, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
authors.forename: Jonas
authors.initials: J
authors.lastname: Gros
authors.affiliation: Environmental Chemistry Modeling Laboratory (LMCE), ENAC, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
authors.forename: Aureline
authors.initials: A
authors.lastname: Grange
authors.affiliation: Environmental Chemistry Modeling Laboratory (LMCE), ENAC, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland; Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland. Electronic address: samuel.arey@epfl.ch.
authors.forename: J
authors.initials: J
authors.lastname: Samuel Arey
mesh_terms: D000465:Algorithms; D002849:Chromatography, Gas / Q000379:methods*; D005742:Gasoline / Q000032:analysis; D006843:Hydrocarbons, Chlorinated / Q000032:analysis; D060106:Lakes / Q000737:chemistry; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis; D015203:Reproducibility of Results
chemical_list: D005742:Gasoline; D006843:Hydrocarbons, Chlorinated; D011084:Polycyclic Aromatic Hydrocarbons
keywords: Baseline correction; Calibration; Chemometric; GC×GC; Peak delineation; Quantification