The monitoring system for feeding rate of Daphnia magna as fluorescent intensity of Chlorella vulgaris was constructed to evaluate toxicities. When 30 daphnids were added to water samples and run the system, the change of the feeding rate by time was measured accuracy. This method revealed that when the toxicants which were potassium dichromate, lead (II) nitrate, Triton X-100, and Benthiocarb were high concentration, the feeding rate decreased compare to the control after 180 minutes exposure. The feeding rate tended to increase linearly after 60 minutes exposure to all toxicants. With low concentrations of toxicants, lead (II) nitrate, Triton X-100, and Benthiocarb, the feeding rate difference 60 minutes exposure and 180 minutes exposure were larger than control. Thus, it was shown that the feeding rate didn't always decrease when toxicants coexisted in low concentration. This method had higher sensitivity than that of acute immobilization test on some toxicants. From these results, it was shown that this system can measure the change of feeding rate. Although it is necessary to improve the sensitivity, conditions, and construction of the system, the toxicity test based on this theory will be used effectively.

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In this study, a thermal degradation pathway of Triphenyltin (TPT) is proposed. The thermal analyses of TPT were performed using elementary analysis (CHO), X-ray diffraction with differential thermal analysis (DTA), differential scanning calorimetry (DSC) and thermogravimetry (TG) .
It was revealed that TPT experienced internal structural changes at 88°C and melted at 123°C . In addition, two phenyl groups were extruded at 230°C resulting in the formation of mono-n-phenyltin hydroxide. Subsequently, degradation to inorganic tin occurred at 380°C following the extrusion of the residual phenyl group at 280 °C. It was determined that TPT was ultimately oxidized to tin oxide in air from the results of the DTA, TG and CHO analyses
From the results of the DSC analysis, the enthalpy of formation (ΔH°_f) of SnO₂ was calculated to be 363 KJ/mol, which is lower than the standard value of 580 KJ/mol. The reason for this lower calculated value was thought to be due to the final products being a mixture of SnO and SnO₂ as evidenced from the experimental results of X-ray diffraction.
TPT is composed of a tetra-hedral structure with four groups sharing the sp³ hybrid orbital of the tin atom and it has one hydroxyl group and three phenyl groups, so that there is a positional molecular distortion. In addition, the TPT molecule has a localized polarity due to the electro-negativity of the hydroxyl radical.
In conclusion, it was suggested that the extrusions of the phenyl groups of TPT occur stepwise, because of the difference in the degree of bonding between the phenyl groups and the tin atom.

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Toxicity Identification and Evaluation (TIE) procedure for sewage and river waters was developed to identify the major substances inducing the estrogenic activity through application to various sewage samples (i.e., influent and effluent of sewage treatment plant and returned sludge from final settling tank) and river waters. The TIE procedure was composed of instrumental analysis and chemical fractionation technique combined with bioassay using recombinant yeast. The samples collected from a municipal sewage treatment plant and Tama River receiving a huge treated wastewater were firstly filtrated, and organic compounds in the dissolved and suspended phases were extracted and subjected to the instrumental analysis and the bioassay. At the same time, the parts of the extracts were subjected to fractionation procedures. In the instrumental analysis, natural estrogens and their conjugates, synthetic estrogen and nonylphenol and its metabolites were measured by LC-MS/MS and HPLC. The estrogenic activities measured by the bioassay were almost comparable with those calculated from the concentrations and relative potencies of the target substances for all samples ranging from river waters to sludge samples. Results from the fractionation technique followed by the bioassay, significant estrogenic activities were observed in two fractions in which E1 and E2 elution were individually confirmed. Also, the contribution by unknown substances to the activities for the sewage samples was estimated to be as small as between 6.7 and 9.4%.

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The multivariate receptor models Positive Matrix Factorization (PMF) was used along with Chemical Mass Balance (CMB) model to evaluate source apportionment of dioxins in air samples collected in Fukuoka prefecture. A total of 210 air samples were obtained from 1999 to 2004 and were analyzed for 116 isomers including coplanar PCBs. The PMF model predicted that the major sources of dioxins in the air samples were waste incineration, PCBs, pesticide pentachlorophenol (PCP) and chloronitrophen (CNP) . The estimated mean source contribution rate of dioxins by the PMF model were as follows: incineration 21%, PCB 35%, PCP 27% and CNP 16%, respectively.
The source profiles calculated from the PMF model were compared with measured source data. Source profiles of incineration, PCB and CNP resembled each other, but PCP was slightly different.
A total of 9 cases including both PMF modeling and measured sources underwent evaluation by the CMB method to determine source contribution for individual air samples. As a result, five cases obtained good estimation. But taking some conditions into consideration, it was thought that the case of three mesaured source data and one PMF profile data (that of PCB) produced relatively better results. According to these source data, source contribution rate of dioxins in air were as follows: incineration 40%, PCB 44.1%, PCP 2.1% and CNP 7.2%, respectively.

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The reactions of pyrethroid insecticides: ethofenprox, permethrin, fenvalerate and flucythrinate, with chlorine in aqueous solution were investigated by GC/MS, in order to understand their chemical fates in water. Ethofenprox was shown to react easily with chlorine under conditions likely to be found during water treatment disinfection, while the moderate reactions were observed for permethrin and fenvalerate pesticides. Flucythrinate was shown not to react with chlorine under such water treatment conditions. The reactions of pyrethroid pesticides with chlorine in water were strongly dependent on the solution pH values and the molar ratios of chlorine to the compound. GC/MS analyses demonstrated that chlorinesubstituted Ethofenproxs and an oxidezed compound are to be present in the chlorinated solutions, as disinfection by-products.

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A gas chromatography/mass spectrometry (GC/MS) method by a solid-phase adsorption/liquid extraction has been used for the determination of phthalates in indoor air. Round robin tests using this method for eleven phthalates such as dimethyl phthalate (DMP), diethyl phthalate-d₄ (DEP-d₄), di-n-propyl phthalate (DPrP), di-n-butyl phthalate (DnBP), di-n-butyl phthalate-d₄ (DnBP-d₄), di-n-pentyl phthalate (DPnP), dihexyl phthalate (DHxP), benzyl-n-butyl phthalate-d₄ (BnBP-d₄), dicyclohexyl phthalate (DcHP), di- (2-ethylhexyl) phthalate (DEHP), and di- (2-ethylhexyl) phthalate-d₄ (DEHP-d₄), and the related compound such as di- (2-ethylhexyl) adipate-d₈ (DEHA-d₈) were conducted by 16 laboratories.
Three kinds of test samples were analyzed by each laboratory: a) hexane solution (sample A) of the phthalates, b) an adsorbent (sample B) to which hexane solution of the phthalates was directly added, c) an adsorbent (sample C) through which a 300l volume of air was passed after addition of hexane solution of the phthalates. The phthalates were extracted from the adsorbents by 2 ml of dichloromethane after addition of fluoranthene-d₁₀ as an internal standard and then determined by the gas chromatography/mass spectrometry (GC/MS) .
Three phthalates, DMP, DnBP and DEHP, were detected in the solvent and blank samples and thus the one third of their data was not considered. The intra-laboratory relative standard deviations (RSDs) of the values for sample A were less than 10% except for DnBP and DEPH. Their inter-laboratory RSDs were in the range of 7.0-40% except for DEPH and increased with the increase of molecular weight of the phthalates. The intra- and interlaboratory RSDs of the values for sample B were in the range of 5.0-17% and 15-45%, respectively. The intra- and inter-laboratory RSDs of the values for sample C were in the range of 5.0-12% and 15-50%, respectively.
These results indicated that the nine phthalates including their deuterated derivatives except for DMP, DnBP and DEPH could be determined precisely by using this method. It should be noted to pay precious attention for analysis and pretreatment of DMP, DnBP and DEPH because of their serious contamination and the possibility of matrix effect extracted from the adsorbent on column separation.

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A Chemical Mass Balance method based on Functional Relationship Analysis (Fr-CMB) was applied to estimate the contributions of sources to polychlorinated dibenzo-para-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in samples of water and sediment collected from rivers in Niigata Prefecture. The assumed sources were as follows; flue gases of wasted incinerators and two banned agricultural chemicals, Chloronitrophen (CNP) and Pentachlorophenol (PCP) .
To determine the classification of various compounds of PCDD/Fs and the data of agricultural chemicals to be used in the analysis, several investigations have been made. The results indicated that it was appropriate to use the ordinary classification of PCDD/Fs mainly composed of 2, 3, 7, 8-homologues, and to use the results summarized by applying k-means clustering to the data of agricultural chemicals collected until now.
The results obtained by Fr-CMB seemed to be more reasonable than those by CMB8, the conventional U.S. Environmental Protection Agency (USEPA) method based on effective variance weighting.

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An accurate, simple and rapid isocratic elution method for the simulutaneous determination of eight catechins in bottled green tea drinks using reversed-phase (RP) high performance liquid chromatography (HPLC) with ultraviolet detecter (UV) and short column (100 mm×4.6 mm i. d., particle diameter 3 μm) has been studied. As a result, good linearity of the calibration curve were obtained in the concentration range from 1 mg l^-1 to 100 mg l^-1 (|r| =0.9998-0.9974) . The detection limits based on S/N=3 were 0.62 mg l^-1 for (-) -gallocatechin (GC), 0.78 mg l^-1 for (-) -epigallocatechin (EGC), 0.59 mg l^-1for (+) -catechin (C), 0.38 mg l^-1 for 7- (β-hydroxyethyl) theophylline, 0.42 mg l^-1 for (-) -epigallocatechin gallate (EGCg), 0.57 mg l^-1 for (-) -epicatechin (EC), 0.48 mg l^-1 for (-) -gallocatechin gallate (GCg), 0.40 mg l^-1 for (-) -epicatechin gallate (ECg), and 0.43 mg l^-1 for (-) -catechin gallate (Cg) in 5 μl injection. The eight catechins and 7- (β-hydroxyethyl) theophylline were separated by an isocratic elution method within 30 min. This Isocratic elution method could be successfully applied to the rapid determination of eight catechins in bottled green tea drinks.

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