title: Flow-injection determination of hydrogen peroxide based on fluorescence quenching of chromotropic acid catalyzed with Fe(II).
abstract: Flow-injection analysis system (FIA system), which was based on Fe(II)-catalyzed oxidation of chromotropic acid with hydrogen peroxide, was developed for the determination of hydrogen peroxide. The chromotropic acid has a fluorescence measured at lambda(em)=440 nm (emission wavelength) with lambda(ex)=235 nm (excitation wavelength), and the fluorescence intensity at lambda(em)=440 nm quietly decreased in the presence of hydrogen peroxide and Fe(II), which was caused by Fe(II)-catalyzed oxidation of chromotropic acid with hydrogen peroxide. By measuring the difference of fluorescence intensity, hydrogen peroxide (1.0 x 10(-8)-1.0 x 10(-3) mol L(-1)) could be determined by the proposed FIA system, whose analytical throughput was 40 samples h(-1). The relative standard deviation (RSD) was 1.03% (n=10) for 4.0 x 10(-8) mol L(-1) hydrogen peroxide. The proposed FIA technique could be applied to the determination of hydrogen peroxide in rain water samples.
authors.affiliation: Analytical and Testing Center of Yanbian University, Gongyuan 977, Yanji 133002, China.
authors.forename: Zhen Hai
authors.initials: ZH
authors.lastname: Li
authors.forename: Dong Hao
authors.initials: DH
authors.lastname: Li
authors.forename: Koji
authors.initials: K
authors.lastname: Oshita
authors.forename: Shoji
authors.initials: S
authors.lastname: Motomizu