The microsuspension assay developed by N.Y.Kado, which is a simple modification of the Ames test, is very useful in testing environmental samples of limited mass, because of its high sensitivity. The modification consists of adding 10 times more bacteria and 5 to 10 times less metabolic enzyme, compared to the plate incorporation method by Ames. This assay is approximately 10 times more sensitive than the original Ames test based on absolute amounts of samples added for determination.
In this paper, methodology of this assay and examples of environmental monitoring, especially exposure assessments by using urine, studies on airborne mutagens indoors and detections of mutagenic fractions by HPLC, were reviewed.

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Main combustion products of poly (vinyl chloride) were polynuclear aromatic hydrocarbons. Formation of chlorine-containing compounds was little. Formation of polychlorinated dibenzo-p-dioxins and dibenzofurans was confirmed. Temperature of maximum PCDDs and PCDFs formation was 600°C. Essential profiles of PCDDs and PCDFs formation at various temperatures were similar. Formation amounts of PCDFs were more than those of PCDDs.

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Determination of pyrizine and quinoline in environmental and biological (fish) samples was investigated using HRGC/MS (SIM) . Outline of the analytical method is as follows: Water samples were distilled after alkalization. Distillates were concentrated under reduced pressure after acidificatin. Concentrates were alkalized strongly with sodium hydroxide solution and extracted with n-hexane. An aliquot of n-hexane extract was injected into gaschromatograph-mass spectrometer equpped with DB-WAX (0.25mm×30m, 0.25μm) capillary column. Sediment and fish samples were distilled after addition of distilled water. The subsequent procedure was the same as above. The detection limits of pyrizine and quinoline using this method were 0.09 and 0.08μg/1 /1 in water samples, 1.6 and 1.6μg/kg in sediment samples, 2.9 and 1.3μg/kg in fish samples, respectively.

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Concentrations of linear alkylbenzenesulf onates (LAS) in water samples from Toyano Lagoon (L. Toyano), 11 drainage channels which drain into L. Toyano and the Shinano River were determined. The concentrations of LAS in waters from the lagoon and the river showed the clearly seasonal changes, decreased in the summer due to the degradation, while there were no obvious seasonal changes in LAS concentrations in waters from the drainage channels. LAS amounts from 7 drainage channels, into which domestic wastewater drains, were estimated at 76 to 81% of the total LAS amounts inflowed to L.Toyano. These results suggest that domestic wastewater was the main source of human pollution loads to L. Toyano.

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An analytical method was studied for the simultaneous determination of 6 major agrochemicals (simazine, atrazine, chlormethoxynil, chloronitrofen, chlorotharonyl and quintozene) in environmental water and sediment samples by gas chromatography/mass spectrometry (GC/MS) equipped with a capillary column. Agrochemicals in water samples were extracted with dichloromethane. The solvent of the extract was converted to hexane after dehydration, and was concentrated to 1 ml. The agrochemicals in the concetrate were determined by GC/MS. In the case of sediment samples, these chemicals were extracted with acetone. The solvent of the acetone extract was converted to dichloromethane and concentrated after dehydration. Furthermore, the dichloromethane of the extracts was converted to hexane once more, and was concentrated. The agrochemicals in the concentrate were cleaned up using a florisil column, and were determined by GC/MS.
The 6 major agrochemicals in environmental samples were able to be determined at the level of ppb by this method. The recoveries of these chemicals in water samples were more than 85%, and those in sediment samples were more than 75% expect chlorotharonyl. This analytical method was estimated to be applied of another agrochemicals which contain the similar structure as shown above.

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A method is described for the determination of triethylamine in environmental samples such as river water and bottom sediment. Triethylamine was distilled from an environmental sample under basic condition, extracted under. The same condition with diethylether, and determined by capillary gas chromatography-selected-ion-monitoring (GC-SIM) . The detection limits from river water and bottom sediment were 0.15 μg/1 and 0.94 μg/kg, respectively. The recoveries from river water and bottom sediment were over 80% with coefficient of variation below 4%. This method have sufficient sensitivity, selectivity, and accuracy to be applicable to environmental samples.

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Trichloroethylene (TCE) is widely used in hardware industries on account of the degreasing ability. Using TCE, it is gradually discharged into environment. As TCE proved to be carcinogenic substance, exhaused gas from hardware factories in which TCE is contained ought to be regurated, even though it would be decomposed in air in a few weeks.
In this paper, in order to estimate the effects of TCE withdrawal device installed in hardware factories, aspects of TCE discharge through various ways and TCE mass balance were researched in A factory as a case study.
TCE in exhaust gas which was collected from over the metalcleaning instrument contained 120-490ppm of TCE. However, after withdrawing TCE concentrations were below 2ppm. Consequently, the withdrawal device proved to be effective, which had more than 99% of collection efficiencies.
The results of TCE mass balance in A factory were as follows. 30% of TCE comsumed in the factory discharged with exhaust gas. And it was withdrawed with the device. The discharge rate of TCE with artificial ventilation, with waste oil and with waste water were 11%, 7%, below 1%, respectively.
Undefined ca. 50% of TCE consumed was estimated to be lost by natural ventilation or by vaporization while storage. Therefore, provided surroundings of the metalcleaning instrument is kept under more airtight conditions and/or TCE storage is maintained more attentively not to be vaporized, the ratio of TCE withdrawn may increase.

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A new method for the determination of trace amounts of acrylamide in environmental samples was developed. Acrylamide was derivatized by bromination to 2, 3-dibromopropionamide (2, 3-DBPA) . The dibromo-derivative was cleaned up through a florisil column, and converted to 2-bromopropenamide (2-BPA) by dehydrobromination with triethylamine. 2-BPA was analyzed by gas chromatography (GC) using an electron capture detector (ECD) and a fused-silica capillary column.
This method was applied to several environmental samples. The detection limits of acrylamide in seawater, bottom sediment and fish were 0.02μg/ 1, 0.13μg/kg, 0.30μg/kg, respectively. The recoveries and relative standard deviations in parenthesis for sea water, bottom sediment and fish were 95% (2.9%), 85% (6.8%), 84% (5.1%), respectively. Analysis by GC/MS (NCI) was also investigated and the detection limit was 1.0pg.

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Determination of pyridine and 2-vinylpyridine in air has been developed using capillary gas chromatography (GC) /mass spectrometry (MS) . These compounds were collected on the Carbotrap^TM sorbent and injected into a GC/MS by using the thermal desorptioncold trap equipment. The detection limit for both the compounds on 30 L-air sampling was 0.3ng/m³. The concentration range detected in real samples was N.D.-16.0ng/m³ for pyridine, and 2-vinylpyridine was not detected in any samples.

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N-Nitroso compounds are well known as carcinogens. N-Nitrosodiethanolamime (NDELA) formed from ethanolamine and nitrite has been found in cutting fluids, tobacco and cosmetics. In this paper, we described a sample preparation method for the analysis of NDELA as a slightlyvolatile nitroso compound. The procedure of the method was as follows;
A mixture of sample (10g) and ammonium sulphamate (0.5g) was set into a distillation apparatus and heated to 100°C, then slightly-volatile nitroso compounds were distilled with the acetone vapor for 1 hr. The distillate was concentrated and silyated with BSTFA. The silylated samples were analyzed by GC-TEA. In this method, NDELA at the concentration of 5ng/kg sample was able to be detected.
In the points of the detection limit and the rapidity of the analysis, this method is more excellent than the previous one. Moreover, this method can be used for analyses of other volatile N-nitroso compounds.

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Analytical method of chlomethoxyfen, chlornitrofen (CNP), chlorothalonil (TPN) and quintozen (PCNB) in air was investigated. Pesticides in air were caught by SEP-PAK C₁₈ cartridge column. The pesticides were extracted with 5ml of n-hexane and determined by gos chromatography-mass spectrometry (GC-MS) . Nine pesticides were detected in air over a golf link. The highest concentrations detected were 110ng/m³ for chlorpyrifos, 140ng/m³ for diazinon, 150ng/m³ for fenitrothion, 0.7ng/m³ for isoprothiolane, 8ng/m³ for chlorothalonil, 14ng/m³ for tolc-lophos-methyl, 17ng/m³ for flutolanil, 6ng/m³ for benf luralin, and 1ng/m³ for pendimethalin.

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There are two analytical methods for determination of organotin (tributyltin compounds (TBT) and triphenyltin (TPT) in environmental samples. The first method is performed by ECD-GC with a column treated with hydrobromic acid. The second method is performed by FPD-GC of alkylated samples. The analytical operation of the first method was mere simple than that of the second method, while the recovery (above 90%) and reproducibility (CV, below 5%) of the first method were almost same as those of the second method. From the results, we used the first method for analysis of organotin compounds in environmental samples.
To clarify the pollution of organotin compounds in Sendai Bay, samples were collected from eight stations in the Bay, and were analyzed. The results showed that the inside of Sendai Port was more polluted with organotin compounds from ship-paints than the outside.

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An attempt to discriminate food aromas using a multisensor array was described by focused on the utilization of semiconductor gas sensors. Other similar attempts such as utilizing a quarts resonator array followed by subsequent pattern recognition analysis using neural networks were briefly reviewed.
Although response properties can be somewhat controlled by doping noble metals into metal oxides (SnO₂), responses of semiconductor gas sensors are nonselective in nature. However, our olfaction system discriminate aroma differences based on the nonselective signals emitted from receptor cells locating at the olfactory epithelium by applying a kind of pattern recognition to the signals. Therefore, responses from a gas sensor array composed of six semiconductor gas sensors were integrated in order to discriminate food aromas using chemometric pattern recognition techniques. The problems to be answered before making such a system were as follows; the minimum number of gas sensors needed for discriminations, methods for standardization of gas sensing conditions and for removing excess amount of ethanol in fermented products, and appropriate pattern recognition techniques.
A semiautomatic headspace concentrator installing a Tenax TA trap was effective to standardize aroma introduction for sensing besides removing excess amount of ethanol from headspace vapors in fermented products. All six sensors in the array responded immediately when thermally desorbed aroma components were introduced into a flask installing the gas sensor array. Response patterns for different samples were similar but the slight differences were well reproduced in every measurement. Chemometric pattern recognition analyses such as factor analysis, cluster analysis and linear discriminant analysis (LDA) were applied to the resulting six dimensional data matrix. LDA suggested that only three gas sensors were sufficient enough to discriminate most sample aromas. Coffee samples, liquors and essential oils were reasonably classified and were discriminated into correct sample groups. Thus facile novel methodology utilizing semiconductor multisensor array and the subsequent pattern recognition analysis showed the capability for discriminating food aromas.

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