Diurnal and seasonal distribution of hydrogen peroxide in seawater of the Seto Inland Sea.

Abstract

Hydrogen peroxide was determined in seawater at the Hiroshima Bay, the Seto Inland Sea under sunny conditions. Concentration of hydrogen peroxide was in accordance with the intensity of the solar radiation. Photochemical production under strong biological activity might be responsible for the pro files of the diurnal and seasonal variation of hydrogen peroxide concentration.The spatial distribution of hydrogen peroxide in the Seto Inland Sea gave a good correlation with salinity, suggesting that the photosensitizer to produce hydrogen peroxide was substances brought from river waters.Hydrated electron as a possible precursor of hydrogen peroxide in the photochemical reaction was generated in seawater collected at the Seto Inland Sea by means of irradiating the third harmonic wave of the YAG laser (355 nm: 60 mJ): The amount generated showed a positive correlation against total organic carbon (TOC) and dissolved organic carbon (DOC) in seawater. This correlation was greately improved by the addition of EDTA. The EDTA treatment suggests the existence of some species obstructed the hydrogen peroxide production. Also, this correlation coefficient was improved when tak ing fluorescent matter instead of TOC or DOC.

Dynamics of UV‐driven hydrogen peroxide formation on an intertidal sandflat

“…Diurnal patterns of peroxide concentrations have been reported previously for surface waters in estuaries (Szymczak and Waite 1988), inland seas (Johnson et al 1989;Fujiwara et al 1993), and also for the Atlantic Ocean (Weller and Schrems 1993). Zika et al (1985), while investigating temporal H,O, variability in the Gulf of Mexico, stated that diurnal trends appear more pronounced in coastal than in oligotrophic open sea waters.…”

“…In freshwater H,O, concentrations range between 30 and 3,200 nmol liter-l (Cooper and Lean 1989;Cooper et al 1989;Price et al 1992;Moore et al 1993). In surface seawaters H,O, concentrations between 30 and 400 nmol liter-' have been recorded, mostly in coastal and estuarine areas (Zika et al 1985;Johnson et al 1989;Price et al 1992;Fujiwara et al 1993). Oligotrophic oceanic water surface concentrations are mostly below or -100 nmol liter-' (Cooper et al 1987;Johnson et al 1989).…”

Chemical Dosimetry System for γ-Ray Irradiation Based on the Formation of Phenol from Aqueous Benzene Solutions

“…Short-life-time reactive oxygen species and radicals, such as hydroxyl radicals, 4,5 NO radicals, 6,7 hydrogen peroxide, 8 and hydrate electrons, 8 are photochemically generated in environmental water by natural sunlight. The author and coworkers have investigated and described a determination technique for some reactive oxygen species and radicals.…”

“…The author and coworkers have investigated and described a determination technique for some reactive oxygen species and radicals. [4][5][6][7][8] For the determination of hydroxyl radicals, many chemical probe methods based on the determination of products formed by reactions between hydroxyl radicals and probe compounds have been reported. In these methods, benzene, 4,5,9 nitrobenzene, 10 benzoic acid, 11,12 terephthalate, 13 2-propanole, 13 methanol 11 and dimethyl sulfoxide 14 were used as the probe compounds.…”

Contribution of the Photo-Fenton Reaction to Hydroxyl Radical Formation Rates in River and Rain Water Samples

“…A 2.8 μg L -1 quinine sulfate dehydrate solution (analytical grade from Nacalai Tesque, Inc.) acidified by sulfuric acid at pH 2.0 was used as the standard for FM, in which the fluorescence intensity was taken as 25 fluorescence units (flu.). 22 The total dissolved iron was determined by using inductively coupled plasma atomic emission spectrometry (Optima 3000, Perkin Elmer). The H2O2 concentration was determined by a method of Sakugawa et al 23 …”