Analytical Sciences

Abstract − Analytical Sciences, 24(2), 201 (2008).

A Sensitive Chemiluminescence Method for the Determination of H2O2 in Exhaled Breath Condensate
Yufei HU, Zhujun ZHANG, and Chunyan YANG
Department of Chemistry, Institute of Analytical Science, Southwest University, Beibei, Chongqing 400715, P. R. China
In this paper, a novel flow injection chemiluminescence (FI-CL) method is proposed for the determination of picomolar L-1 levels of hydrogen peroxide (H2O2) in exhaled breath condensate (EBC). This method is based on the oxidation of a low concentration of luminol (10-7 M) by H2O2 at a low concentration level (< 10-8 M) in an alkaline medium catalyzed by a complex, K5[Cu(HIO6)2] (DPC), which is not interfered by other metal ions or horseradish peroxidase (HRP). Under the optimum conditions, H2O2 was determined over the range of 1.0 × 10-10 to 1.0 × 10-8 mol L-1 with a detection limit of (3σ) of 4.1 × 10-11 mol L-1. The relative standard deviation (RSD) was 3.2% for 5 nmol L-1 H2O2 (n = 7). The proposed method offers the advantages of ultra-sensitivity, selectivity, simplicity and rapidity for H2O2 determination. It was successfully applied to directly determine trace amounts of H2O2 (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).