The interest in using supercritical fluid extraction (SFE) as a replacement for conventional liquid solvent extraction for organic pollutants from environmental samples has increased rapidly because of need to reduce liquid solvent use as well as to perform more rapid sample preparations. There are many factors such as pressure, temperature, modifier addition etc. in the application of SFE, and are many researches concerning the development of quantitative methods for the recovery of organics. This paper describes the principles of SFE and numerous environmental applications. Further, the characteristics of operational factors and optimization of extraction condition are discussed with reviewing literatures.

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A study for extraction characteristics of Hg (II) from soils was conducted to develop a rapid extraction method for leachable Hg (II) in the environment.
For the Hg (II) batch extraction from 1g of soil to which Hg (II) was added, l0ml of 1×10^-1mol·1^-1 CaC1₂ solution extracted more amount of Hg (II) from any soil we used than ion-exchanged water, and extraction time (10min-6 hr) did not affect the Hg (II) extracted amounts. The pH of CaC1₂ solution (3.0 11.0) did not have an influence on the Hg (II) amounts extracted from the soil. The ratio of [Hg (II) amount extracted by CaC1₂ solution] to [Hg (II) amount extracted by ion-exchanged water] correlated to the soil carbon content.
On the basis of these results, it is concluded that the 1×10^-1 mol·1^-1 CaC1₂ solution was useful as a solution for the rapid extraction method of leachable Hg (II) in the general soil environment.

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Iron, manganese, zinc, copper, lead, nickel, cadmium, cobalt, and mercury were determined in 23 tissues and organs of loggerhead turtles (6 females and 1 male), in order to understand fundamental information for heavy metal monitoring in sea turtle species. These heavy metal con-centrations and burdens were high in liver, kidney, pancreas, and hard tissues, while low in brain and fat tissue. However, markedly high zinc concentration was found in fat tissue. Zinc concentration in fat was about ten times higher than in fat of marine mammals and seabirds species previously reported. Furthermore, total burden of zinc in fat comprised more than 10% of the whole body burden. More than 10% of copper burdens to whole body burden were found in eggs and ovary, suggesting that copper may be easily transfered to reproductive organs.

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Ambient ozone was sampled by the use of passive sampling filter impregnated with ρ-acetamidophenol (AAP) . Ozone reacted with AAP to form 2, 2'-dihydroxy-5, 5'-diacetylamino-biphenyl which was determined by reversed phase high performance liquid chromatograph with fluorescence detection at 420nm. The average concentration of ozone was determined with less than 9.7% relative standard deviation in time weighted average concentration of 19-234 ppb·day. The method was expected to be suitable for long-term monitoring of ozone in ambient air.

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Elution of tris (2-chloroethyl) phosphate from waste plastics was investigated. A large amount of tris (2-chloroethyl) phosphate was eluted from vinyl-coated wires and vinyl sheet and the elution level was over 100ng per gram of plastics.

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Inorganic mercury was detected in a number of well waters in region A of Fukuoka prefecture, and the highest concentration (well B) found in the region was about forty times higher than the limit of standard. In order to investigate the source of mercury in these wells, the following stu-dies were carried out. First, the core samples bored in region A were extracted under standard elution condition; mercury was not detected in any of the eluates. Second, eluates from the sediment of pond C were analyzed, because the region around well B is a reclaimed land from pond C. The results indicated that possibility of elution of mercury from the sediment was low. Third, the ionic composition of well waters were analyzed: the ion diagram of the well water containing highest mercury was different from those of the other wells, indicating that the source of water in well B is different from the other wells. Consequently, it seems that the high concentration of mercury in well B comes from a particular underground stream which is contaminated with mercury naturally or accidentally.

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In order to obtain some information on the thermo-chemical reactions of chlorinated phenyl-phenols during thermal treatment of activated sludge and combustion system of municipal solid waste incinerator, pyrolysis of these compounds in a quartz reaction tube at 300-700°C under an air stream for 3 min were performed and their products were analyzed by GC-MS.
Pyrolysis of 2-phenylphenol (2-PP) and 4, 6-dichloro-2-phenylphenol (4, 6-DC-2-PP) was shown to produce large amounts of dibenzofuran and dichlorodibenzofuran (DCDF) by dehydrogenation and ring closures, respectively and small amounts of chlorobiphenyls by deoxygena-tion. On the other hand, pyrolysis of 2, 6-dichloro-4-phenylphenol gave small amounts chloro-biphenyls by deoxygenation. Formation of DCDF from 4, 6-DC-2-PP was observed on heating at 400°C and the maximum yield of this compound was obtained at 520°C. It, therefore, seems that thermo-chemical reactions of 4, 6-DC-2-PP in an air stream proceed by mainly dehydrogenation to form DCDF.

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A method for simultaneous determination of asulam, mecoprop, oxin-copper, thiram, bensu-lid, iprodione and pencycuron in environmental water, was developed. In this method, these seven pesticides were concentrated from water using polystyrene-gel minicartridge (PS-2), and determined by HPLC with a GOLF-PAK column. When this method was applied to environmental water samples collected monthly from April 1994 to March 1995 at 11 sampling points in Chiba Prefecture, many interfering peaks were observed. In order to remove these interfering peaks, two columns of GOLF-PAK and Inertsil ODS-3 were used for environmental water samples. By using of these two columns, no interfering peaks were observed, and the peaks of the seven pes-ticides were detected clearly.
When this two-columns method applied to the same samples collected from Chiba Prefecture, no peaks of these seven pesticides was detected in all of them.

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Effect of bacterial concentration on sensitivity of umu-test, was examined. Salmonella typhi-murium strain TA1535/pSK1002 was cultured in a L-type culture tube and diluted into 1, 2, 5, 10, 20, 50 and 100 fold with new medium, and used to detect the response to 4NQO. As a result, when the bacterial suspension was diluted into 10 to 20 fold to make 3-6×10⁸ cells/ml, a good response was observed.

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