title: A sensitive chemiluminescence method for the determination of H2O2 in exhaled breath condensate.
abstract: In this paper, a novel flow injection chemiluminescence (FI-CL) method is proposed for the determination of picomolar L(-1) levels of hydrogen peroxide (H(2)O(2)) in exhaled breath condensate (EBC). This method is based on the oxidation of a low concentration of luminol (10(-7) M) by H(2)O(2) at a low concentration level (< 10(-8) M) in an alkaline medium catalyzed by a complex, K(5)[Cu(HIO(6))(2)] (DPC), which is not interfered by other metal ions or horseradish peroxidase (HRP). Under the optimum conditions, H(2)O(2) was determined over the range of 1.0 x 10(-10) to 1.0 x 10(-8) mol L(-1) with a detection limit of (3sigma) of 4.1 x 10(-11) mol L(-1). The relative standard deviation (RSD) was 3.2% for 5 nmol L(-1) H(2)O(2) (n = 7). The proposed method offers the advantages of ultra-sensitivity, selectivity, simplicity and rapidity for H(2)O(2) determination. It was successfully applied to directly determine trace amounts of H(2)O(2) (nmol L(-1)) in human's EBC of both rheum and healthy volunteers. A statistically significant difference was found between patients with rheum (n = 11) and control subjects without rheum (n = 11).
authors.affiliation: Department of Chemistry, Institute of Analytical Science, Southwest University, Beibei, Chongqing, PR China.
authors.forename: Yufei
authors.initials: Y
authors.lastname: Hu
authors.forename: Zhujun
authors.initials: Z
authors.lastname: Zhang
authors.forename: Chunyan
authors.initials: C
authors.lastname: Yang
mesh_terms: D001944:Breath Tests / Q000379:methods*; D002384:Catalysis; D003300:Copper / Q000737:chemistry; D045853:Exhalation; D017022:Flow Injection Analysis / Q000379:methods; D006801:Humans; D006861:Hydrogen Peroxide / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D007452:Iodates / Q000737:chemistry; D007700:Kinetics; D008163:Luminescent Measurements / Q000295:instrumentation / Q000379:methods*; D008165:Luminol / Q000737:chemistry; D010084:Oxidation-Reduction; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D007452:Iodates; C524140:potassium diperiodatocuprate(III); D008165:Luminol; D003300:Copper; D006861:Hydrogen Peroxide