title: Optimization and validation of an ion chromatographic method for the simultaneous determination of sodium, ammonium and potassium in exhaled breath condensate.
abstract: An ion chromatographic method with conductivity detection for the simultaneous quantification of sodium, ammonium and potassium in exhaled breath condensate (EBC) was developed and validated. A factorial design was used to optimize the chromatographic conditions, which resulted in baseline separations of the cations within 6 min. The method requires no pre-treatment of EBC samples. The optimized method was used for the intra-individual screening of cations in EBC of 10 healthy volunteers. The LOQs were low (0.3, 0.1 and 0.2 microM for sodium, ammonium and potassium, respectively), compared with levels detected in healthy volunteers. The responses were linear with good precision, and samples could be stored for at least 10 weeks at refrigerating conditions.
authors.affiliation: Occupational and Environmental Medicine, Sahlgrenska University Hospital and Academy at Göteborg University, SE-41266 Göteborg, Sweden. sophie.svensson@ymk.gu.se
authors.forename: Sophie
authors.initials: S
authors.lastname: Svensson
authors.forename: Ann-Charlotte
authors.initials: AC
authors.lastname: Isacsson
authors.forename: Göran
authors.initials: G
authors.lastname: Ljungkvist
authors.forename: Kjell
authors.initials: K
authors.lastname: Torén
authors.forename: Anna-Carin
authors.initials: AC
authors.lastname: Olin
mesh_terms: D001944:Breath Tests; D002138:Calibration; D002853:Chromatography, Liquid / Q000379:methods*; D006801:Humans; D011188:Potassium / Q000032:analysis*; D000644:Quaternary Ammonium Compounds / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012964:Sodium / Q000032:analysis*
chemical_list: D000644:Quaternary Ammonium Compounds; D012964:Sodium; D011188:Potassium