Chemical Analyses of Seawater for Trace Elements Recent Progress in Japan on Clean Sampling and Chemical Speciation of Trace Elements A Review

Nakayama, Eiichiro; Suzuki, Yuzuru; Fujiwara, Kitao; Kitano, Yasushi

doi:10.2116/analsci.5.129

Cited by 27 publications

(16 citation statements)

References 23 publications

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“…In much of the open ocean, total dissolved iodine (speciated between iodate and iodide) is constant to a few percent of a concentration of ∼60 µg l −1 (Barkley and Thompson, 1960;Elderfield and Truesdale, 1980;Nakayama et al, 1989). Such a value is consistent with iodine concentrations 31 Figure 3.…”

Section: Introductionmentioning

confidence: 62%

The 129-iodine content of subtropical Pacific waters: impact of Fukushima and other anthropogenic 129-iodine sources

et al. 2014

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Abstract.Results obtained from a dedicated radiochemistry cruise approximately 100 days after the 11 March 2011 Tohoku earthquake and subsequent disaster at the Fukushima Daiichi Nuclear Power Plant show that Fukushima derived radionuclides in the nearby ocean environment had penetrated, on average, to ≤ 250 m depth (1026.5 kg m 3 potential density surface). The excess inventory of Fukushima-derived 129 I in the region (∼150 000 km 2 ) sampled during the cruise is estimated to have been between 0.89 and 1.173 billion Bq (∼136 to ∼179 grams) of 129 I. Based on a tight tracer-tracer relation with 134 Cs (or 137 Cs) and estimates that most of the excess cesium is due to direct discharge, we infer that much of the excess 129 I is from direct (non-atmospheric deposition) discharge. After taking into account oceanic transport, we estimate the direct discharge, i.e., that directly released into the ocean, off Fukushima to have been ∼1 kg 129 I. Although this small pulse is dwarfed by the ∼90 kg of weaponstesting-derived 129 I that was released into the environment in the late 1950s and early 1960s, it should be possible to use Fukushima-derived 129 I and other radionuclides (e.g., 134,137 Cs) to study transport and entrainment processes along and across the Kuroshio Current.

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Section: Introductionmentioning

confidence: 62%

The 129-iodine content of subtropical Pacific waters: impact of Fukushima and other anthropogenic 129-iodine sources

et al. 2014

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“…0.059 ' (2) where EFe (0.77 V vs. NHE) and E°v (1.00 vs. NHE) are the standard redox potentials of the Fe"/Fell and Vv/Vlv systems, respectively. The equilibrium constant Kv_Fe is calculated to be 10at pH=O.…”

Section: Resultsmentioning

confidence: 99%

Effect of Ligands on the Iron(III)/Iron(II) System and Its Novel Application to the Simultaneous Flow Injection Determination of Vanadium(IV) and Vanadium(V)

1994

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A new simultaneous flow injection determination of vanadium(IV) and vanadium(V) has been proposed with photometric detection. The method is based on the effect of ligands on the formal redox potential of the iron(III)/iron(II) system. The potential of the redox system increases due to the presence of 1,10-phenanthroline (phen); vanadium(IV) is thus easily oxidized by iron(III) to vanadium(V), producing an Iron(II)-phen complex (Amax=510 nm). On the other hand, the presence of diphosphate causes an increase in the reducing power of iron(II) because of a decrease in the potential of the system. Thus, the reduction of vanadium(V) by iron(II) takes place easily. By using an FIA system and measuring the absorbance of the complex at 510 nm, the simultaneous determination of vanadium(IV) and vanadium(V) is possible based on both reactions. The proposed method makes it possible to obtain both positive and negative FIA peaks corresponding to the concentrations of vanadium(IV) and vanadium(V) alternatively by a single injection of the sample solution. Vanadium(IV) and vanadium(V) at the 10-6 mol dm3 level can be determined at a rate of 30 samples h-1(60 peaks h-1).

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“…The results obtained by radiochemical neutron-activation analysis also show good agreement for bottles of mineral water from the same batch (Radenska, King's Spring; Roga~ka, Donat), when the second analysis was done a year after the first. The reason for [23][24][25]. Because of the practically constant value for iodine in sea-water, and the lack of standard reference materials for iodine in an aqueous matrix, water samples from the open sea can serve as a reference or "certified" material for validation of results for iodine in analysis of various water samples.…”

Section: Resultsmentioning

confidence: 99%

Iodine in mineral waters: A comparison of results from two analytical techniques

et al. 1991

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Abstract.A comparative study of the determination of iodine in mineral waters is presented. Iodine was first determined by a standard titrimetric method and the results obtained were compared with those obtained by the faster and more sensitive radiochemical neutron activation method. For a series of waters, the results obtained by the two techniques were in fair agreement for the higher concentration levels of iodine, but for very low iodine levels the titrimetric method was insufficiently sensitive. The RNAA procedure was checked by standard addition experiments, and shown to be also valid when iodine was present as iodate.Key words: iodine, mineral waters, titrimetry, radiochemical neutron activation analysis.Underground waters with a higher content of dissolved mineral substances or compounds (> 1 g/l) and gases (> 250 mg/1) and with natural biological purity are classified as mineral waters [1,2]. The utilization of mineral waters for drinking and medico-balneological purposes necessitates reliable quantitative data on their essential micro-constituents, including iodine.Correlations between endemic goitre and iodine deficiency date from the last century. Clinical research on this phenomenon in different parts of the world also shows a good correlation between goitre and the iodine content of drinking waters. The frequency of its incidence is higher in areas where the iodine content in drinking waters is less than 3 #g/l, and iodination of the water considerably reduces this effect /-3, 4]. In comparison with normal ground and surface waters, mineral waters are usually enriched with iodine, though this can depend on the geological structure of

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Chemical Analyses of Seawater for Trace Elements Recent Progress in Japan on Clean Sampling and Chemical Speciation of Trace Elements A Review

Cited by 27 publications

References 23 publications

The 129-iodine content of subtropical Pacific waters: impact of Fukushima and other anthropogenic 129-iodine sources

The 129-iodine content of subtropical Pacific waters: impact of Fukushima and other anthropogenic 129-iodine sources

Effect of Ligands on the Iron(III)/Iron(II) System and Its Novel Application to the Simultaneous Flow Injection Determination of Vanadium(IV) and Vanadium(V)

Iodine in mineral waters: A comparison of results from two analytical techniques

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