In order to achieve the rapid analysis of PCB in insulating oil, optimization of the operating conditions of the GC-MS/NCI method, including ion source temperature, emission current, reaction gas and gas volume estimation, was carried out.
Only a dilution with n-hexane was enough in our pre-treatment process, instead of the complicated pre-treatment such as clean-up processes with column chromatography, the extraction/concentration process, etc., to analyze the samples with a level down to 0.3 mg/kg-PCB, which was less than 0.5 mg/kg-PCB, the pre-treatment criteria in the relevant Japanese law.
The correlation between our method and the official one was fairly good in terms of the test results using the samples of insulating oil containing PCB after de-chlorination treatnent.
In conclusion, we could develop the rapid PCB analysis method by using a GC-MS/NCI method.
The time for analysis could be reduced to less than 1 hour, and the virtually no wastes were produced during pretreatment procedure.
The method is suitable for routine monitoring of PCB during operation of PCB treatment plants.

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A dissolution test by the acid rain actually falling in Toyama Prefecture was conducted on carbon steel plates, bronze plates, aluminum alloy plates, copper plates and the lead plates.
As for the metal elements, various straight regression lines were given between the amount of dissolution and the exposure periods. Though most elements were on the straight regression lines through origin, the lines of Si, Mg and Pb did not run through the origin.
Ion concentration in the rain touched on the metal plate was different from the ion concentration in the rain water. Many ions showed significant differences in the t-test between the rain water and the rain touched on the metal plate. The occurrence of the chemical reaction and the corrosion formation on the surface of the metal plate was suggested.
The relationship between the leaching quantity and the environmental factors causing the corrosion was estimated using multiple regression analysis by monthly variation. These results showed that the leaching quantity of each metal is affected by environmental factors, especially the amount of rainfall and the pH.

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The bottom environment of Osaka Bay was assessed by comparing organometal composition of sediments from inner part of the bay (along shore from Kobe City to Osaka City) with those in coasts along Awaji Island. The organometals designated in this study are those extracted by toluene-methanol mixed solvent. The result showed that human effects seem to be stronger in the inner bay than in the area along Awaji Island; the former shows higher concentrations of Mg, Cr, As, Ni, Se, Sn, Hg, Pb, Co, Cu and Zn. The main results obtained in this study are;
1. The concentration of organomagnesium is apparently higher by 2-3 orders of magnitude in comparison with other organometals, suggesting the large contribution of chlorophyll contained in phytoplankton. The higher concentration of organomagnesium in sediments from the inner bay suggests that human-supplied nutrients may cause higher production of phytoplankton. The positive correlation of organomagnesium with organoarsenic and organolead suggests the possibility that arsenic and lead are also concentrated by phytoplankton.
2. Sediments from the mouth of Shin-Yodo River are enriched in organic forms of Co, Cu, Hg, Ni, Zn, Sn, Se, and Pb and those from the mouth of Muko River are enriched in organic forms of Co, Cu, Zn, Sn, As, Se, and Pb. Those metals may orginate as pollutants from the river. However, all these organometals are not necessarily human-derived, because some may originate from other processes such as absorption of inorganic metals onto terrigenous highmolecular weight organic matter and from biological activity.

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A cyclic steam extraction was applied to extraction of nitrobenzene and chloronitrobenzenes in environmental samples for GC/MS determination.
A water sample of 500 ml, a sediment sample of 20 g with 500 ml purified water, or a homogenized fish sample of 10 g with 500 ml purified water was added with a surrogate compound (nitrobenzene-d₅), 15 g of sodium chloride and 5 ml of hexane. The target compounds were extracted from samples by using an essential oil distillator for 90 min. The hexane extract was dried, and was concentrated for clean up by column chromatography. The eluate was concentrated to 1 ml, added with an internal standard, and the target compounds were determined by GC/MS.
The recoveries of terget compounds corrected by those of the surrogate compound were 95.1 to 102.9% for water sample, 97.4 to 100.4% for sediment sample, 97.0 to 102.9% for fish sample. The detection limits were 0.022 to 0.041μg·l^-1for water, 2.4 to 4.1μg·kg^-1for sediment and 3.9 to 4.7μg·kg^-1for fish.

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We deviced an experimental method for the higher-sensitivity detection in Dioxin analysis by introducing a local cold trap in the end of the separation column. An eluted component is once trapped selectively, then it is introduced to the ionization port of MS. As a result of this technology applied to the congeners of hepta- and octa- CDDs/CDFs, the band width of the corresponding peaks became small distinctly. The detection sensitivity for hepta- and octa- CDDs/CDFs was improved in 4.5-10.2 times.

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Effect of water content in gas on adsorption of vapor PCDD/Fs by activated alumina was studied. The adsorption rate of vapor PCDD/Fs by activated alumina rapidly decreased at water contents of 25 %v/v and 33 %v/v, and the decrease was remarkable in lower chlorinated PCDD/F congeners. The adsorption rate was also positively correlated with the retention time of PCDD/F isomers on polar column (SP-2331) in GC-MS. These results suggest that an adsorption of vapor PCDD/Fs by activated alumina is affected by competition between dioxins and water on polar sites of alumina. In case of using activated alumina as adsorbent of PCDD/Fs in exhaust gas from incinerator, cooling method by mixing with air was thought to be effective, because gas cooling method by mixing with water will cause increase of water content in gas, and results in higher loss of PCDD/Fs.

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Variation of estrogenic activities during the bio-degradation of bisphenol A (BPA) with isolated bacteria strain MO6 were measured using the yeast two-hybrid assay method. Accumulation of a degradation intermediate, 4, 4'-dihydroxy-α-methylstilbene (DHMS), depended on the pre-incubation conditions of degrading bacteria. Thus, maximum estrogenic activity during the bio-degradation of BPA varied with the pre-incubation conditions of degrading bacteria. In a case when a high concentration of DHMS was accumulated, estrogenic activity rose to a level corresponding to 1, 600 mg/l BPA although the initial BPA was only 30 mg/l. Even in another case when a low concentration of DHMS was accumulated, estrogenic activity rose to a level corresponding to 150 mg/l BPA, three times that of initial BPA concentration.
Temporal increase in estrogenic activity was observed in only 1 of 8 samples, when BPA was degraded by a river water. In the river water, DHMS did not seem to be accumulated such a level that the contribution to the estrogenic activity was detectable.

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Separation of PUBs from insulating oil is required for the analysis of PCBs in insulating oil. However, separation was difficult because of physical and chemical similarity of these materials.
In the present study, gel-permeation chromatography, used occasionally for the analysis of pesticides or herbicides in vegetables, was investigated to separate PCBs from insulating oil. It was found that over 95% of insulating oil was removed by the method.
The outline of PCBs analysis developed in the present study is as follows;
(1) Organic substances were treated by gentle rotation of hexane solution of insulating oil and sulfuric acid by magnetic stirrer.
(2) PCBs were separated from insulating oil by gel-permeation chromatography.
(3) PCBs were analyzed with GC/ECD or GC/MS.

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