Concentrations of trace elements in an ice core obtained in the polar region have been determined by inductively coupled plasma mass spectrometry (ICP-MS) . For trace metals in the ice core, sample uptake and high sensitivity for analysis are also important due to the limited volume of sample and the low concentrations of analytes. A desolvated micro-concentric nebulizer (MCN-6000), which is a recent development and offers high nebulizer efficiency at low sample consumption volume, in combination with ICP-MS, permitted multi-element determination of ppt levels of Al, V, Cr, Fe, Cu, Zn, As, Ag, Cd, Pb and U within a 2ml sample from a ice core obtained from the Vestfonna ice cap (89° 58' N, 21° 02' E) in Nordaustlandet, Svalbard. The contamination on the ice core exterior was removed with a stepwise melting process. The concentrations of Al, Fe, Cu, Zn and Pb were determined from the results of this analysis.

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An analytical method for the determination of 2-methyl-4-chlorophenoxybutyric acid (MCPB) and its primary metabolite 2-methyl-4-chlorophenoxyacetic acid (MCPA) residues in peas was developed utilizing liquid-liquid partitioning, derivatization of acids with diazomethane, Florisil^® column cleanup, and gas chromatography/mass spectrometry. Method validation recoveries from various pea matrixes (peas without pods, peas with pods, and dry peas) ranged from 69-108% for MCPB and 60-94% for MCPA, over four levels of fortification (0.01, 0.10, 0.50, and 1.0 ppm) . Control and MCPB-treated pea samples collected from six IR-4 (USDA, Interregional Research Project No. 4, Minor Use Pesticide Registration Program) field sites had residue levels less than 0.01 ppm, except for one that had 0.017 ppm. The method was validated down to the limit of quantitation at 0.01 ppm and to the limit of detection at 0.0045 ppm.

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Environmental survey on 285 chemicals in coastal waters around Kitakyushu City was carried out for 1 year. The results are as follows. (1) The number of chemicals detected was 179 which included 12 endocrine disruptors. Most of the chemicals detected were the same as chemicals found in leachates from hazardous waste disposal sites in Japan. (2) Factories and a sewage treatment plant in Dohkai bay were the main sources of the chemicals and the chemical pollution spread to outside of the bay. (3) Chemicals detected at high concentrations in Dohkai bay were polyaromatic hydrocarbons, which were discharged from coke oven factories, and chlorobenzenes and aromatic amines, which were used for organic synthesis. (4) 2-Nitrophenol and benzothiazole whose source seemed to be vehicles were detected at high frequency. (5) High correlation was found among the pesticides used for the same purpose. Hexachlorocyclohexanes, which were banned 25 years ago, were also found.

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In tap water derived from river water, the total concentration of all halogenated disinfection by-products was the lowest (slightly less than 50μg/l) during winter but gradually increased, reaching a peak (slightly over 200μg/l) in August. According to the classes of halogenated by-products, haloacetic acids and trihalomethanes were major by-products, haloacetaldehydes, haloacetonitriles and haloacetones were medium by-products, and halopropionic acids and halonitromethanes were minor by-products. Among the medium by-products, the haloacetaldehydes concentration was always higher than haloacetonitriles concentration. Evaluation of individual halogenated by-products in each class revealed the following findings. In trihalomethanes, the concentration of chloroform was the highest, showing clear seasonal variation while that of other by-products was low, markedly decreasing in the order of bromodichloromethane, dibromochloromethane, and bromoform. In haloacetonitriles, dichloroacetonitrile as a major by-product showed seasonal variation while bromochloroacetonitrile and dibromoacetonitrile as minor by-products showed nearly constant concentration during the year. In haloacetones, seanonal variation was observed in 1, 1, 1-trichloroacetone (a major by-product) but not 1, 1-dichloroacetone (a minor by-product) . In haloacetaldehydes, seasonal variation was observed in trichloroacetaldehyde (a major by-product) but not in dichloroacetaldehyde (a minor by-product) . In haloacetic acids, dichloroacetic acid was a major by-product, trichloroacetic acid was a medium by-product, and bromochloroacetic acid and dichlorobromoacetic acid were minor by-products. In halopropionic acids, 2, 2-dichloropropionic acid was a major by-product, and 2, 3-dichloropropionic acid was a minor by-product.
In tap water derived from the mixture of river water and ground water, the total concentration of all halogenated by-products was low in winter and high in summer (about 100-200μg/l) fiein some samples but showed no seasonal variation (slightly less than 100 -slightly more than 150μg/l) in others. The order of the concentrations of the halogenated by-product classes was similar between the tap water derived from the mixture of river water and ground water and that derived from river water except that the haloacetaldehydes concentration was lower than the haloacetonitriles concentration in the former. Compared with individual halogenated by-products in the river water-derived tap water, trihalomethane cantaining bromine atom increased in trihalomethanes, dibromoacetonitrile in haloacetonitriles, tribromoacetaldehyde in haloacetaldehydes, and dibromochloroacetic acid in haloacetic acids while the dichloroacetic acid concentration decreased.
Tap water after advanced water treatment showed no seasonal variation in the total concentration of halogenated by-products (about 50-100μg/l) . The concentration order of the classes of halogenated by-products in this tap water was the almost same as that in the tap water derived from a mixture of river water and ground water. The concentrations of all individual halogenated by-products were lower in this tap water than in the river water-derived tap water.
Even when the same tap water was supplied, the tap water via the water receiving tank elevated tank showed a higher total concentration of halogenated by-products than the tap water from main supply tube directly. In addition, the total concentration of halogenated by-products was higher in the water kept in receiving tank elevated tank for a longer period. Since the water receiving tank/elevated tanks investigated in this study were in a relatively sealed state, the concentrations of all classes of halogenated by-products except haloacetones and major halogenated by-products in each class showed good correlation with the residence time of the water in the tanks, i.e., the time of contact with effective residual chlorine.

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Using a gas instantaneous water heater for heating below the boiling point, halogenated disinfection by-products as a whole and according to classes increased in some tap water samples but decreased in others with an increase in the temperature of the tap water. the tendency depends on the quality and quantity of halogenated by-products precursors in the tap water. Using a large-sized boiler or electric water warmer, total halogenated by-products and trihalomethanes and haloacetic acids increased, and volatile halogenated by-products as intermediate by-products decreased irrespective of its quality or quantity of by-products precursors.
Compared with heating below the boiling point using an instantaneous water heater, a large-sized boiler, or an electric water warmer, the heating temperature is higher, and the heating time is longer using an electric pot or a kettle. All volatile halogenated by-products except trihalomethanes disappeared after heat retention for 0-5 minutes following boiling at 100°C using an electric pot and after continuous boiling at 100°C for 0-5 minutes using a kettle. Trihalomethane disappeared after heat retention for 3-6 hours following boiling at 100°C using an electric pot and after continuous boiling at 100°C for 5-10 minutes using a kettle. After disappearance of trihalomethanes, only haloacetic acids remained among halogenated by-products. The remaining haloacetic acids was mainly dihaloacetic acid.

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Swimming pool water contained not only halogenated disinfection by-products derived from tap water but also those derived from swimmers. The pool water examined in this study was tap water derived from river water containing negligible bromide. Therefore, halogenated disinfection by-products derived from swimmers were those of chlorine series.
According to the classes of halogenated by-products, the concentration of haloacetic acids and haloacetaldehydes were extremely high, followed in order by trihalomethanes, haloacetones and haloacetonitriles, and the halopropionic acids concentration was the lowest.
The main by-products in each halogenated by-products class were trichloroacetic acid and dichloroacetic acid in haloacetic acids, trichloroacetaldehyde in haloacetaldehydes, chloroform in trihalomethanes, monochloroacetone in haloacetones, dichloroacetonitrile in haloacetonitriles and 2, 2-dichloropropionic acid in halopropionic acids. Among them, the concentration of trichloroacetic acid, dichloroacetic acid and trichloroacetaldehyde were especially high.

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We studied removal of halogenated by-products, i.e., their leakage, in tap water using a small-sized home water treatment unit with an activated carbon hollow fiber membrane by our multi-component systematic analysis method for halogenated disinfection by-products in water supply.
An operation method generally used in homes showed higher leakage, i.e., less removal, rates for all halogenated by-products except haloacetaldehyde compared with the continuous water flow method. Using the method generally used in homes, leakage of halogenated by-products was observed even at the time of the installment of the small-sized home water treatment unit. During the cartridge effective period, each halogenated by-product leaked despite differences in the leakage rate.
In the method generally used in homes, the leakage rate according to halogenated by-product classes was the highest for haloacetic acids and trihalomethanes, followed by haloacetaldehydes and haloacetones. In the classes showing the highest leakage rates, the leakage rates of chloroform, tribromoacetic acid and dibromochloroacetic acid were high.
The activated carbon in the home water treatment unit removes halogenated by-products primarily by physicochemical adsorption but partly by biological action.

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Study on the determination of acrylamide in exhaust gas was conducted for two methods. In one method, acrylamide was collected by using Sep-Pak Plus PS-2 cartridge conditioned with methanol and was eluted with methanol. Propionamide was added to the eluate as an internal standard for capillary gas chromatography-mass spectrometry (GC/MS) and gas chromatography -flame thermoionic detection (GC/FTID) . In the other method, acrylamide was collected by bubbling the sample through 20me of water. After dibromination, extraction, dehydrobromination and addition of the internal standard, acrylamide was determined by GC/MS and GC/FTID. The detection limits, the relative standard deviations and the recoveries in the former method were 21.8μg/m³, 3.2-6.6%, 99.8%-102% in the GC/MS, and 89.0μg/m³, 5.3-9.0%, 99.9%-108% in the GC/FTID, respectively. Those in the latter method were 37.3μg/m³, 6.6-7.8%, 88.7%-97.6% in the GC/MS, and 63.7μg/m³, 3.7-9.1%, 79.6%-94.0% in the GC/FTID, respectively. The both methods were successfully applied to determine acrylamide in exhaust gas.

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