Determination of hydrogen peroxide in exhaled breath condensate by flow injection analysis with fluorescence detection.
A method for the determination of hydrogen peroxide in exhaled breath condensate (EBC) by automated flow injection analysis (FIA) with fluorescence detection was developed and validated. In the enzymatic assay a fluorescent dimer of para-hydroxyphenyl acetic acid (HPAA) was formed by the redox coupling reaction between hydrogen peroxide and horseradish peroxidase (HRP). The calibration curve of hydrogen peroxide was linear over a range of 40-5000 nM. The coefficient of variation (CV) for within-day precision was 1-3%; for between-day precision, it was 2-5% over the validated range. The assay requires a small sample aliquot (150 microl) and no incubation time, and has an analytical runtime of < 2 min. It is therefore suitable for larger studies. The method was used to detect hydrogen peroxide in EBC of asthmatic patients and healthy volunteers. A statistically significant difference was found between patients with asthma (n = 19) and control subjects without asthma (n = 19), 780 nM versus 480 nM (P = 0.03).
Occupational and Environmental Medicine, Sahlgrenska University Hospital and Academy at Göteborg University, Sankt Sigfridsgatan 85, SE-41266 Göteborg, Sweden. sophie.svensson@ymk.gu.se
Sophie
S
Svensson
Anna-Carin
AC
Olin
Mona
M
Lärstad
Göran
G
Ljungkvist
Kjell
K
Torén
D001249:Asthma / Q000378:metabolism; D001944:Breath Tests; D016022:Case-Control Studies; D017022:Flow Injection Analysis / Q000379:methods*; D006801:Humans; D006861:Hydrogen Peroxide / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods*
D006861:Hydrogen Peroxide