title: Tracking matrix effects in the analysis of DNA adducts of polycyclic aromatic hydrocarbons.
abstract: LC-MS using electrospray ionization is currently the method of choice in bio-organic analysis covering a wide range of applications in a broad spectrum of biological media. The technique is noted for its high sensitivity but one major limitation that hinders achievement of its optimal sensitivity is the signal suppression due to matrix inferences introduced by the presence of co-extracted compounds during the sample preparation procedure. The analysis of DNA adducts of common environmental carcinogens is particularly sensitive to such matrix effects as sample preparation is a multistep process which involves "contamination" of the sample due to the addition of enzymes and other reagents for digestion of the DNA in order to isolate the analyte(s). This problem is further exacerbated by the need to reach low levels of quantitation (LOQ in the ppb level) while also working with limited (2-5 μg) quantities of sample. We report here on the systematic investigation of ion signal suppression contributed by each individual step involved in the sample preparation associated with the analysis of DNA adducts of polycyclic aromatic hydrocarbon (PAH) using as model analyte BaP-dG, the deoxyguanosine (dG) adduct of benzo[a]pyrene (BaP). The individual matrix contribution of each one of these sources to analyte signal was systematically addressed as were any interactive effects. The information was used to develop a validated analytical protocol for the target biomarker at levels typically encountered in vivo using as little as 2 μg of DNA and applied to a dose response study using a metabolically competent cell line.
authors.affiliation: Department of Chemistry and Chemical Biology and Barnett Institute, Northeastern University, Boston, MA 02115, USA.
authors.forename: Joshua J
authors.initials: JJ
authors.lastname: Klaene
authors.affiliation: Department of Chemistry and Chemical Biology and Barnett Institute, Northeastern University, Boston, MA 02115, USA.
authors.forename: Caroline
authors.initials: C
authors.lastname: Flarakos
authors.affiliation: Department of Chemistry and Chemical Biology and Barnett Institute, Northeastern University, Boston, MA 02115, USA.
authors.forename: James
authors.initials: J
authors.lastname: Glick
authors.affiliation: Graduate School of Biomedical Sciences, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; Environmental and Occupational Health Sciences Institute, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA.
authors.forename: Jennifer T
authors.initials: JT
authors.lastname: Barret
authors.affiliation: Graduate School of Biomedical Sciences, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; Environmental and Occupational Health Sciences Institute, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; NIEHS Center for Environmental Exposures and Disease, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; Department of Environmental and Occupational Medicine, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA.
authors.forename: Helmut
authors.initials: H
authors.lastname: Zarbl
authors.affiliation: Department of Chemistry and Chemical Biology and Barnett Institute, Northeastern University, Boston, MA 02115, USA. Electronic address: p.vouros@neu.edu.
authors.forename: Paul
authors.initials: P
authors.lastname: Vouros
mesh_terms: D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide / Q000031:analogs & derivatives / Q000032:analysis; D001564:Benzo(a)pyrene / Q000032:analysis / Q000494:pharmacology; D002274:Carcinogens, Environmental / Q000032:analysis* / Q000494:pharmacology; D002478:Cells, Cultured; D002853:Chromatography, Liquid; D018736:DNA Adducts / Q000032:analysis* / Q000494:pharmacology; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000032:analysis; D006801:Humans; D013058:Mass Spectrometry; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*
chemical_list: D002274:Carcinogens, Environmental; D018736:DNA Adducts; D011084:Polycyclic Aromatic Hydrocarbons; C056612:benzo(a)pyrene-DNA adduct; D001564:Benzo(a)pyrene; D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide; C040060:7,8-dihydroxy-9,10-epoxide-7,8,9,10-tetrahydrobenzo(a)pyrene-10-deoxyguanosine; D003849:Deoxyguanosine
keywords: Benzo[a]pyrene; DNA adducts; Ion suppression; Matrix effects; Polycyclic aromatic hydrocarbons