title: Sensitive determination of isoprostanes in exhaled breath condensate samples with use of liquid chromatography-tandem mass spectrometry.
abstract: Oxidative stress is the hallmark of various inflammatory lung diseases. Increased concentrations of reactive oxygen species in the lungs are reflected by elevated concentrations of oxidative stress markers in the breath, airways, lung tissue and blood. The aim of this work was to develop a method for the fast measurement of F2-isoprostanes in exhaled breath condensate (EBC) samples using equipment which is nowadays available and routinely exploited in analytical laboratories, liquid chromatography coupled with tandem mass spectrometry. Because of the limited volume of an EBC sample and the very low concentrations of biomarkers, we chose lyophilization as the preconcentration technique. The diastereoisomers determined show similar fragmentation patterns, which is why complete chromatographic separation with excellent peak shapes was essential for accurate quantitation. Isoprostanes were separated using a narrow-bore Agilent Extend C-18 column in isocratic elution mode using acetonitrile/methanol and water with the addition of 0.01%(v/v) formic acid. The limits of determination and quantitation for the determination of four isoprostanes in samples of EBC ranged from 1 to 3 pg/ml. The recoveries of all isoprostanes ranged from 96.7 to 101.7, with a relative standard deviation of <7%. The stability of the isoprostanes at different temperatures was measured as well.
authors.affiliation: Department of Analytical Chemistry, Chemical Faculty, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland. mjanicka@hotmail.com
authors.forename: Monika
authors.initials: M
authors.lastname: Janicka
authors.forename: Paweł
authors.initials: P
authors.lastname: Kubica
authors.forename: Agata
authors.initials: A
authors.lastname: Kot-Wasik
authors.forename: Jacek
authors.initials: J
authors.lastname: Kot
authors.forename: Jacek
authors.initials: J
authors.lastname: Namieśnik
mesh_terms: D000097:Acetonitriles; D015415:Biomarkers / Q000032:analysis / Q000737:chemistry; D001944:Breath Tests / Q000379:methods*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004355:Drug Stability; D045853:Exhalation; D006801:Humans; D028421:Isoprostanes / Q000032:analysis* / Q000737:chemistry; D016014:Linear Models; D000432:Methanol; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012907:Smoking; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013696:Temperature
chemical_list: D000097:Acetonitriles; D015415:Biomarkers; D028421:Isoprostanes; D000432:Methanol; C032159:acetonitrile