A method for the determination of 1, 2, 5, 6, 9, 10-hexabromocyclododecane (HBCD) in water, sediment and fish samples has been developed. HBCD in water was adsorbed on solid phase (SDB-XD) and eluted with acetone and dichloromethane. The extract was dehydrated and replaced to hexane. Then the hexane solution was concentrated and cleaned-up with a Florisil cartridge column. HBCD in sediment was extracted with acetone. The extract was added to a 5 % NaCl solution and then target compound was extracted with hexane. The extract was cleaned-up with conc. H₂SO₄and a Florisil cartridge column. A biological sample was homogenized and extracted with acetonitrile. Lipid in the extract was removed by acetonitrile-hexane partition and then treated as the same as sediment. If necessary, silicagel cartridge column clean-up was added. Determination was carried out by GC/MS-SIM. The detection limits were 0.087 μg/l in water, 23μg/kg in sediment and 7.1 μg/kg in fishes.

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We evaluated the effects of 15 different organic solvents in the luminescentumutest, a simplified version of the conventionalumutest, by determining the amount of luminescence induced by each solvent and considering its toxicity and stability of the solvents with regard to the following 15 types of solvents: methanol, dimethyl sulfoxide, acetonitrile, 1, 4-dioxane, tetrahydrofuran, acetone, cyclohexane, ethyl alcohol, N, N-dimethylformamide, ethylene glycol monophenyl ether, ethylene glycol dimethyl ether, glycerol formal, 1-methyl-2-pyrolidone, tetrahydrofurfuryl alcohol, and formamide. We found that cyclohexane, methanol, acetonitrile, ethanol, and acetone could be used in the test. Methanol, in particular, was effective for determining the mutagenicity of environmental samples.

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The point which exceeded an environmental standard for water quality of 1pg-TEQ/lby the Dioxins environmental pollution survey at river in Kanagawa prefecture had been found. In our following survey, the emission of Dioxins from the soldering process in a factory was confirmed.
Dioxins were generated inde novosynthesis while some organic compounds were pyrolyzed in coexistence of metals during soldering process. This study investigated the conditions of Dioxins formation in soldering process using an experimental tubular furnace. Soldering was usually performed in the use of a flux containing compounds, hydrocarbon and chloride ion in supply. A large amount of Dioxins was especially formed under coexist of iron or copper with aromatic hydrocarbon and inorganic chloride ion. The increase of the amount of organic compounds and hydrogen chloride, and the increase of surface area of copper advanced the formation of Dioxins. It was made clear that Dioxins were generated in the process of the coexistence of metals as the catalyst, hydrocarbon and chloride ion, and the temperature up from room temperature, like the soldering process.

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Our previous report showed that the heating (60°C) multilayer silica gel columns, i.e., AgNO₃silica gel and H₂SO₄silica gel, was useful as purification method for dioxins analysis. In this study, further simplified-and automated-preparation method for dioxins analysis using HRGC-HRMS and Bioassay was studied on three successive steps of the purification, concentration and solvent substitution.
The results showed the best suitable condition as follow: An alumina column as concentration and solvent substitution was set under multilayer silica gel column. Dioxins sample in hexane was applied on a top of multilayer silica gel column. After heating the column at 60°C, dioxins were eluted with 60 mlofn-Hexane kept at 60°C, and then followed by drying the alumina column with N₂gas. Thereafter, dioxins in alumina column were reversibly eluted with 0.5 mlof Toluene or DMSO solution kept at 60°C, and determined by GC-MS or Bioassay. This newly developed method for dioxins analysis was considered to be useful for reduction of analytical time, amount of solvent, and cost.

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Indium and thallium in 35 river water samples and one lake water in Okayama Prefecture, Tottori Prefecture and Shimane Prefecture were determined by inductively coupled plasma mass spectrometry (ICP-MS) . To measure the dissolved indium and thallium, water samples were filtrated with a membrane filter of 0.45 μm pore size and the residues were decomposed with nitric acid and perchloric acid.¹¹⁵In and²⁰⁵Tl were measured, because these isotopes have the highest abundances. Since¹¹⁵Sn interfered the signal of¹¹⁵In, the intensity of¹¹⁵In signal was corrected by measuring the concentration of Sn by ICP-MS. The concentration of In in the filtration residues and dissolved In were in the range of n.m.-18.0 ng/l and n.m.-55.4 ng/l, respectively. Tl in the filtration residues and dissolved Tl were in the range of n.m-1290 ng/l and n.m.-145.2 ng/l, respectively (n.m. means “less than measurement limit”) . Measurement limits (10σ) in the mass measurement for In in the filtration residue and dissolved In were 0.6 ng/l and 0.2 ng/l, respectively, Those for Tl in the filtration residue and dissolved Tl were 7.2 ng/l and 1.3 ng/l respecively. The relative standard deviations of the results (n=3) for In was 9.9-17.7 % and those for Tl was 8.6-14.9 %.

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To elucidate existence form of dioxins (PCDD/DFs and Co-PCBs), six samples of paddy (1), plowland (1), forest soils (2) and sea sediments (2) were separated into 6 particle-size fractions using the physical separation method¹⁾, and particle-size distributions of dioxins associated with composition of soil organic matter were studied.
For most of the samples examined, the greastest proportion of dioxins was in the finest particle-size fraction (400- mesh), but for forest soils being in the large particle-size fraction (9-60 mesh) . Size-related accumulations of dioxins generally depended on the amounts of soil organic matter. However, a quantity and/or humification of humic acid also affected the relative enrichment of dioxins in finer particle fractions of paddy and plowland soils, which might be due to the interparticle redistribution of surfactant-soluble dioxins derived from pesticides. While for sediments a part of size distributions of dioxins might be complexed by a wide form of dioxin derived from soil particle, fly ash, wastewater and biological detritus, and for forest soils dioxins adsorbed on plant leafviaambient air involving fly ash and exhaust gas might directly affected their existence form. Furthermore, a relative enrichment of high-chlorinated PCDD/DFs and non-orthoPCBs was found in the finer particle fractions associated with increasing amounts of humic acid, as compared to the other PCDD/DFs and Co-PCBs.
These observations indicate that the existence form of dioxins in soil and sediments is influenced by differences in characteristics of soil organic matter and/or emission source of dioxins, and their information is available to learn chemical and biological aspect and decomposition of dioxins.

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The operational conditions for high-resolution gas chromatograph (HRGC) /quadrupole mass spectrometry (low-resolution mass spectrometry, LRMS) for dieldrin and endrin measurement were examined in order to apply the isotope dilution method. The molecular ion (M+; m/z380 and 382) for dieldrin and the fragment ion ( [M-Cl] + ; m/z345 and 347) for endrin were set up as monitor ion for LRMS measurement. The calibration curves of dieldrin and endrin were sufficiently linear. The variation coefficient of the relative response factor of dieldrin and endrin were within 5 %. The minimum limits of determination for the sample were 0.72 ng g^-1for dieldrin and 0.78 ng g^-1for endrin, respectively. Analytical reference material [JSAC 0442 (Slow conc.) ] was measured by LRMS. The result was a range of the certificated value.

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