In this study, the storage capability of canister for air sampling was evaluated. Sixty-four volatile organic compounds (VOCs) were spiked into ambient air sample to be 0.4-2 ppbv in canister in order to examine storage stability, and 43 VOCs found from ambient air sample, minimum concentration was 0.002 ppbv, were examined storage stability in the canister. After about a month's storage, 28 of them were successfully recovered. Very volatile organic compounds such as chlorofluorocarbons were also stable over a month. Some polar compounds such as acrylonitrile and 1, 3-butadiene were not so stable as non-polar VOCs. Acrylonitrile of ppbv level in concentration were stable or decreased gradually during the storage, and that of quite lower level in concentration was increased under the same condition. Persistence of aldehydes and its increase in both Silico- and SUMMA- canisters, even cleaned, were observed during storage. Similar phenomenon, though its magnitude was very low, was observed about acrylonitrile. These can be explained as residual polar compounds or their decomposition products which still remained in the cleaned canister, gradually shifted from innersurface of the canister to the gas phase. 1, 3-Butadiene was also decreased under the same storage condition. The Japan Environment Agency has authorized the same canister method as evaluated on this study, and throughout Japan, acrylonitrile and 1, 3-butadiene have been measured with 7 other prior hazardous compounds that were stable over a month in the canister. If the storage is over a long period, air concentrations of acrylonitrile may be overestimated and that of 1, 3-butadiene may be underestimated.

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Five methods for estimating the limit of detection are compared with regard to the estimates of LOD and reproducibility of the LOD estimates in GC/HRMS for dioxins. The following methods are taken:
1. LOD based on repetition:
Three times SD of area measurements (area SD, n = 5) ;
Three times SD of height measurements (height SD, n=5) ;
2. LOD based on S/N:
Six times SD of baseline noise (baseline SD) ;
Six fifths of envelope of baseline (baseline range) ;
3. LOD based on probability theory of signal and noise (FUMI theory) .
The LOD estimates obtained from the above methods, except the height SD, are comparable to each other. The reproducibility of the LOD estimates is ca. 30 % RSD for the area SD, height SD and baseline range, ca. 20 % RSD for baseline SD and ca. 15 % RSD for the FUMI theory. The FUMI theory is concluded to be the best choice from the viewpoints of statistical reliability and practicality.

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A survey on the particle-size distribution of elements in indoor and outdoor air was performed in 20 homes in 6 Japanese cities. Size distributions of concentrations of 18 elements (Mg, Ti, V, Cr, Mn, Ni, Cu, Zn, Mo, Ag, Sb, Cs, Ba, La, Ce, Pr, Nd, Pb) varied considerably in outdoor and indoor air. The highest contributions for outdoor concentrations of Sb and Pb were from particles smaller than 2.5 μm in diameter, while the concentration of Mg and Ti was the highest from particles larger than 2.5 μm. Indoor concentrations of Zn, Mo, Sb, Pb were predominated by particles smaller than 2.5 μm. The presense of indoor sources of particles or elements was assessed on the basis that BaP could be regarded to be tracer of particles originating from outdoors and penetrating into the indoor air. Most of indoor concentrations of elements in fine particles were almost the same as those outdoors indicating these elements in the indoor particles originated predominantly from outdoors. There are certain indoor sources of the elements in particles larger than 2.5 μm. In contrast to the above mentioned elements, indoor concentrations of 6 elements (Cu, Ag, La, Ce, Pr, Nd) were higher than those of outdoors indicating the presense of their indoor sources. A principle component analysis was conducted for outdoor and indoor elemental concentrations. The results for outdoor concentrations reflected the sampling locality, but the results for indoor concentrations did not.

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Studies have been carried out on 1) long term monitoring of volatile organic hazardous air pollutants by using an automated monitoring system which consists of average sampling system and GC/MS, and 2) comparison of the monitoring data with those measured by established manual method (canister method) . Twenty six pollutants were detected from atmosphere, where 38 were monitored by the automated system. Throughout more than 1 month continuous monitoring, retention time of almost all compounds and qualifier/target ion intensity ratio of internal standard (fluorobenzene) were stable. Monitoring data by the automated monitoring system agreed with those measured by canister method at about 60 % of detected compounds at atmosphere. However a few compounds such as Dichloromethane did not give concordant results in comparison study. Relation coefficient between monitoring data by the two methods were high for most of compounds except for 5 halogenated compounds, concentrations of which are almost constant.

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Analytical conditions of ICP-MS has been developed for precise and rapid determination of gallium and indium in environmental samples. The sample was digested with HF/HNO³/HClO⁴, then Ga and In were determined by internal standardisation method to compensate for non-spectroscopic interferences arising from matrix elements in the sample solution. Rhodium was found to be effective as an internal standard.
Barium bivalent ion and ³⁷Cl¹⁶O₂ polyatomic ion interferences with ⁶⁹Ga intensity became markedly, therefore a measurement of Ga at ⁷¹Ga was essential.
Ga analytical results of eight certified reference materials showed good agreement with the reference values. The analytical precisions of Buffalo River Sediment and SL-1 were 1.3 and 0.4 % respectively.
On the other hand, In analytical results were not obtained by proposed method in certified reference materials (Buffalo River Sediment, 1633a and JLK-1) since isobaric interference from tin could not be neglected, and it could not be detected in the other materials because of its low concentrations.
The proposed method was applied to the determination of Ga and In in various environmental samples. Ga was detected in the range from 11.4 to 21.0μg/g in sediments, 6.94 to 14.7μg/g in sewage sludge, fly ash and suspended particulates. In was not detected in sediments and suspended particulates, while it was detected in sewage sludge and fly ash, but analytical results were not obtained because of significant isobaric interference from tin. Ga concentration was in the range from <0.01 to 1.1μg/l and In was in the range from < 0.01 to 0.30μg/l in river water (15 points) .
The determination limits (10δ) of these elements were 0.01μg/l in solution, and 0.1μg/g in solid environmental samples.

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An analytical method for the determination of microcystins with liquid chromatography/mass spectrometry (LC/MS) has been developed. Under reversed-phase liquid-chromatographic conditions, microcystin-RR, YR and LR have been analysed using electrospray ionization (ESI) methods. The effect of the liquid chromatographic mobile phase, the effect of the fragmentor voltage with ESI methods and the capillary voltage with simultaneous acquisition using positive/negative ion mode on the sensitivity of microcystins were examined. A membrane extraction disk was used as solid phase extraction (SPE) for the isolation and the trace enrichment of microcystins from river water samples. The extracts were directly injected into LC/MS system. The minimum quantitation limit (MQL) defined as ten fold standard deviation for five replicate analysis of these microcystins ranged from 14 to 16 pg/ml and the minimum detection limit (MDL) defined as three fold standard deviation ranged from 4 to 5 pg/ml. The overall recoveries of these compounds were from 89.3 to 94.2 % {RSD (n = 5) from 5.6 to 6.8 % } for river water.

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In order to investigate the present state of marine environment in Niigata Prefecture, and to investigate the behavior of rare earth elements (REEs) in the ocean, REEs in many kinds of seaweed samples taken on the coast in Niigata Prefecture were determined by inductively coupled plasma mass spectrometry (ICP-MS) .
Seaweed samples were taken at 10 spots on the coast in Niigata Prefecture including Sado Island on August, 2000. After decomposing the samples, REEs were separated by solvent extraction method.
The following results are obtained. (1) Even in the same phylum (e.g., green algae, brown algae, or red algae), concentrations of REEs vary widely depending on the species of seaweed. (2) A large difference was found between REE patterns of the seaweed samples taken on the coast in Niigata Mainland and those on the coast in Sado Island. It shows that the surrounding marine environment seems to be an important factor for determining REE pattern as well as the species of seaweed. (3) As to REE pattern of some seaweed samples taken on the coast in Niigata Prefecture, Yb-anomaly was found as well as Ce-, and Eu-anomaly. (4) REE pattern of seaweed samples may be an useful tracer of investigating the surrounding marine environments.

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Response characteristics of quartz crystal resonator (QCR) coated with organic sensory film prepared by radio-frequency sputtering of organic materials, either a synthetic polymer or a biomaterial was investigated from the view point of application to a sensor array or electric nose for monitoring indoor air quality. As a model of indoor air, odors vaporized from six kinds of essential oils of woody note (cedar wood, rose wood, sandal wood, eucalyptus, star anise, and pine) at small intensity as a sensing threshold for human olfactory system were monitored with QCR sensors. All film coated QCRs showed Langmuir-type adsorption/absorption characteristics to each odor that should be a mixture of several gaseous substances. By means of principal component analysis (PCA), data plots of six odors were well separated in the scoreplot obtained through the PCA with an accuracy of 91 % according to k-nearest neighbor method. The compactly assembled QCR sensor module (6.5 cm × 9.5 cm ×5 cm) was set in a smoking area, and continuous monitoring under room air was demonstrated. Simultaneously, monitoring with a carbon dioxide sensor and a relative humidity/temperature sensor were performed. The frequency vs. time response curve of each film coated QCRs was composed of a long-span baseline drift and a quick response recorded as a pulse-shape curve within several minutes, which revealed QCR sensor's ability of monitoring under normal room air. The baseline shift seemed synchronized with the change in relative humidity. Some pulse-shape responses appeared when no other sensor's response was observed, which indicated the film coated QCRs only could detect some changes of the indoor air in the smoking area.

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Using a portable GC/MS equipped with a Pre-column Separation Inlet System, separation of 2, 3, 7, 8-chloro-substituted congeners was carried out. Characteristics of the system lie in an efficient removal of matrix, protection of GC column from excess matrix loading and rapid analysis of any selected congener. Target compounds were tetra-chlorinated dioxins and pentachlorinated dioxins having chlorines at 2, 3, 7 and 8 positions. The analysis of dioxins was conducted by using one and the same GC column. As a result of an experiment in standard solutions, possibility of selective quantitation for toxic congeners was expected. Using the system, reduction of noise in chromatogram was observed. Application of the system to soil samples has been also reported.

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Distribution and seasonal variation of 81 compounds (pesticides and transformation products) in approximately 200 water samples of Ishikari river were monitored during two years (1998. 4-2000. 3) at two sampling sites. In this monitoring, 20 herbicides, 12 fungicides, 13 insecticides and 3 transfomation products were detected from the river at 0.001 μg/l-0.821 μg/l in median. The total pesticides concentrations in all river water samples increased during and after their application. There was a distinct seasonal peak in herbicide concentrations during June and July, while those fungicide and insecticide concentrations during July and August.
The load of a compound is the mass of that compound transported in a stream during a specified period. The load can be estimated as the product of the concentration of the compound and the flow volume of the river measured at the Ishikariohashi Bridge and Karikiohashi Bridge.
The total annual loads of pesticides in Ishikari river streams was estimated as 4.53 tons.

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A simple method using liquid chromatography with tandem mass spectrometry (LC/MS/MS) has been developed for the determination of 1-nitropyrene (1-NP), 1, 3dinitropyrene (1, 3-DNP), 1, 6-DNP and 1, 8-DNP in airborne particulates. This method consists of ultrasonic extraction, clean-up using silica gel cartridge and LC/MS/MS. Four nitroarenes can be analyzed with the following detection limit: 1 pg for 1-NP 2 pg for 1, 3-DNP, 1, 6-DNP and 1, 8-DNP. The recoveries of 1-NP 1, 3-DNP, 1, 6-DNP and 1, 8-DNP were 100 %, 101 %, 102 % and 98 %, respectively.

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We determined 50 components (5 components and 45 elements) in two snowfalls and a rime-ice of ice-monster collected at Mt. Hakkoda and Rokkasho-mura in Aomori prefecture using ion chromatography, ICP-AES, ICP-MS and high-resolution ICP-MS. Element concentrations ranged almost 8 orders of magnitude (mg/kg to pg/kg) . The snow samples showed pH of about 5 and rime sample showed 4.4, indicating these samples were acidic. The element concentrations in rime sample were generally higher than these in snowfall. Relative concentrations in rime and snow samples, however, were very similar to each other. And also, chondrite-normalized rare-earth elements (REE) patterns in samples were very similar to each other and flat pattern at heavy REE area with Eu negative anomaly. This pattern was similar to those in natural fresh water samples such as river water. These results suggest that the acidifying materials in the snow and rime-ice have similar origin.
In addition, we performed a water extraction experiment using three type of standard reference materials; vehicle exhaust particulates (NIES-8), coal fly ash (JCFA-1 and NIST-1633), and soil (IAEA-7) . Only the water extract of vehicle exhaust particulate showed low pH. Relative concentrations of dissolved components in the extract were very similar to those in the snow and rime samples. On the other hand, the extracts from coal fly ash and soil did not show low pH, and relative element concentrations were different from snow and rime samples. The results suggest that vehicle exhaust particulates could be potential candidate of acidifying substance of the snowfall in Tohoku area (north of Japan) .

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Dry-ice has higher heat absorption capacity by 1.5-2.5 times than others among common refrigerants and is versatile to use for sample preservation in cooling condition because of its changing phase from solid at the beginning to gas at the end of use. In this report, the practical use of dry-ice in the form of pulverized state as well as with organic solvents or water are at first described. Then, the efficiency of the various thermal insulation containers such as plastic boxes and dewar vessels were tested. The loss rates of dry-ice in the containers were indicated as the weight decrease and were determined to be 40-100 g/hr* and 10-50 g/hr for plastics boxes (wall thickness; 1.6-6.5 mm, volume; 2-40l) and dewar vessels (made of glass and stainless steel, volume; 1-10l), respectively, at 24-28°C . Heat transfer rates (HTR) for these were also estimated from the loss rates to be 0.3-1.3 kcal/ (m²·hr·°C) and 0.2-0.6 kcal/ (m²· hr· °C), respectively. The samples can be safely preserved for 3 or 7 days under - 70°C with 10 kg or 36 kg of pulverized dry-ice without adding any dry-ice while storing, respectively, by using FRP (fiber reinforced plastics) boxes, of which the wall inside is packed by urethane foam (wall thickness 4-6.5 cm) . It allowed us to shipsuccessfully the samples with maintaining below -70 °C from far places such as remote islands or overseas area to the analytical laboratory by commercial delivering systems. The problems on getting the dry-ice at various places and on packing of sample traps into pulverized dry-ice bed in the boxes are also herein described.
*; hr = hour.

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