西岡 洋

This study was undertaken to evaluate the adsorption potential of a naturally available, cost-effective, raw eucalyptus bark (EB) (Eucalyptus sheathiana) biomass, to remove organic methylene blue (MB) dye from its aqueous solutions. Effects of various process parameters such as initial dye concentration, adsorbent loading, solution pH, temperature, presence of salts, mixture of dyes and surfactant onto MB dye adsorption by bark material were studied. Significant effect on adsorption was witnessed on varying the pH of the MB solutions. Results showed that the optimum pH lies between 7.4 and 10.0. The extent (%) of MB adsorption from aqueous solution decreased with the increase in the initial MB dye concentration, but increased with rise in temperature. The extent of MB dye adsorption was found to be enhanced due to increase of salts concentration. This is because of salting-out-effect, which comprises the changes of various short range forces. The overall kinetic studies showed that the MB dye adsorption by EB biomass followed pseudo-second-order kinetics. The mechanism of MB dye adsorption was analysed by intra-particle diffusion model and desorption study. Free energy change of adsorption (G degrees), enthalpy change (H degrees) and entropy change (S degrees) were calculated to predict the nature of adsorption. The Langmuir adsorption isotherm model yields a better correlation coefficient than the Freundlich model and the dimensionless separation factor R-L indicated favourable adsorption process. The maximum Langmuir monolayer adsorption capacity of raw EB for MB dye was found to be 204.08mg/g at 30 degrees C. A single-stage batch adsorber design for MB dye adsorption onto EB biomass has been presented based on the Langmuir isotherm model equation. The results obtained in this study suggest a promising future for inexpensive raw EB biomass as a novel adsorbent and a better alternative to activated carbon adsorbent used for the removal of MB dye from dye bearing effluents.

a- and b-axis-oriented (Bi3.25Nd0.75-xEu x)Ti3O12 (BNEuT, x = 0-0.75) films of 3.0 μm thickness were fabricated on conductive Nb:TiO2(101) substrates containing 0.79 mass% Nb by high-temperature sputtering at 650 °C, and their structural and ferroelectric characteristics were investigated. All the films had a mostly single-phase orthorhombic structure, with high degrees of a- and b-axis orientations of 99.0-99.8%. The lattice parameters (a-, b-, and c-axis lengths) and the calculated orthorhombic lattice distortion decreased monotonically with increasing Eu content. The microstructure of BNEuT films with x = 0-0.50 was nanoplate-like, whereas that of films with x ≥ 0:60 was significantly more bulklike. The real room-temperature remanent polarization (2Pr*), taking the porosity between the nanoplates into account, had a maximum value of 2Pr* = 87 μC/cm2 at x = 0.10, which was approximately 1.3 times larger than that (65 μC/cm2) of the nondoped BNT film. It is shown that lattice distortion caused by rotation of octahedra in the a-b plane due to the Eu substitution plays a significant role in the improvement of ferroelectricity. © 2013 The Japan Society of Applied Physics.

The cotyledon of legume seeds is a storage organ that provides nutrients for seed germination and seedling growth. The spatial and temporal control of the degradation processes within cotyledons has not been elucidated. Calcium oxalate (CaOx) crystals, a common calcium deposit in plants, have often been reported to be present in legume seeds. In this study, micro-computed tomography (micro-CT) was employed at the SPring-8 facility to examine the three-dimensional distribution of crystals inside cotyledons during seed maturation and germination of Lotus miyakojimae (previously Lotus japonicus accession Miyakojima MG-20). Using this technique, we could detect the outline of the embryo, void spaces in seeds and the cotyledon venation pattern. We found several sites that strongly inhibited X-ray transmission within the cotyledons. Light and polarizing microscopy confirmed that these areas corresponded to CaOx crystals. Three-dimensional observations of dry seeds indicated that the CaOx crystals in the L. miyakojimae cotyledons were distributed along lateral veins however, their distribution was limited to the abaxial side of the procambium. The CaOx crystals appeared at stage II (seed-filling stage) of seed development, and their number increased in dry seeds. The number of crystals in cotyledons was high during germination, suggesting that CaOx crystals are not degraded for their calcium supply. Evidence for the conservation of CaOx crystals in cotyledons during the L. miyakojimae germination process was also supported by the biochemical measurement of oxalic acid levels. © The Author 2012. Published by Oxford University Press [on behalf of Japanese Society of Microscopy]. All rights reserved.

a- and b-axis-oriented Bi3. 25Nd0. 75Ti3O12 (BNT) nanoplates, 3. 0-μm thick, were fabricated on conductive Nb:TiO2(101) substrates with 0. 79 mass% Nb at 650 °C by high-temperature sputtering. Successively, the fabrication of inorganic-organic composites was carried out by introducing an epoxy resin to the spaces between the BNT nanoplates. The fourier transform infrared spectroscopy (FTIR) and the energy dispersive X-ray (EDX) elemental mapping results confirmed that the fabricated composites were inorganic-organic hybridized materials with cured epoxy resin introduced into the spaces between the BNT nanoplates. Piezoelectric response measurements of the fabricated BNT-epoxy resin composites by using piezoresponse force microscopy (PFM) showed that the composites have potential as piezoelectric microelement materials. © 2013 The Korean Physical Society.

海水中のセシウムイオンを除去するための無機イオン交換体をカキ殻や浄水汚泥およびガラスなどの無機廃棄物から合成した。海水中でのセシウムイオン除去率は72％であった。本吸着材は天然ゼオライトと比べて迅速にセシウムイオンを吸着することが判明した。

BiFeO₃(BFO) thin films with various Bi/Fe ratios have been deposited on SrRuO₃/SrTiO₃(001) substrates by dual ion beam sputtering. A Bi₂O₃ceramic disk and an $\alpha$-Fe₂O₃powder disk were used as targets, and simultaneously sputtered using a dual ion beam. Bi/Fe ratio has been controlled by adjusting the beam current ratio on the Bi₂O₃- and $\alpha$-Fe₂O₃-side ion sources. Even a BFO thin film with a Bi/Fe ratio of 0.95 and a smooth surface shows a slightly leaky characteristic. $[\text{Fe$^{2+}$}]/([\text{Fe$^{3+}$}]+[\text{Fe$^{2+}$}])$ ratio has been estimated by Auger electron spectroscopy (AES). From the AES profiles, the $[\text{Fe$^{2+}$}]/([\text{Fe$^{3+}$}]+[\text{Fe$^{2+}$}])$ ratio of the BFO thin film with a Bi/Fe ratio of 0.95 is estimated to be 0.14. It is considered that not only improving surface roughness but also enhancing oxidization is important for reduction in leakage current.

Perovskite-structured solid solutions with compositions of 0.9963{(1 - x)(Bi1/2Na1/2)TiO3-xBa(Cu1.1/3Nb2/3)O-3} + 0.0037MnO(2), with x = 0-0.06 [abbreviated as (1 - x) BNT-xBCN)], were fabricated by normal sintering, and their structural, and piezo- and ferroelectric properties were investigated in detail. The X-ray diffraction profiles of the (1 - x) BNT-xBCN solid solutions with x = 0-0.06 suggested that the rhombohedral-tetragonal morphotropic phase boundary (MPB) in this material system is in the compositional region x = 0.0425-0.0460. The cross-sectional transmission electron microscopy (TEM) images and selected-area electron diffraction (SAED) patterns of the (1 - x) BNT-xBCN samples with x = 0.0475 suggested that the present materials have a modulation structure arranged by a double period along the [111] direction. It is shown that the tetragonal BNT-BCN (x = 0.0475) solid solution with a composition of 0.9490BNT center dot 0.0473BCN center dot 0.0037MnO(2) near the MPB has a piezoelectric coefficient (d(33)), a relative permittivity (epsilon(T)(33)/epsilon(0)), and a remanent polarization (P-r) of approximately 1.8, 3.2, and 2.8 times larger, respectively, than those of the BNT solid solution without BCN substitution. (C) 2011 The Japan Society of Applied Physics

3.0-mu m-thick a- and b-axis-oriented (Bi3.25Nd0.75)Ti3O12 (BNT-0.75) films were fabricated on conductive Nb:TiO2(101) (Nb = 0, 0.048, 0.46, 0.79 mass%) single crystal substrates by high-temperature sputtering. BNT films grown on undoped TiO2 substrates have no orientation, whereas BNT films deposited on Nb:TiO2 substrates with 0.46-0.79 mass% Nb show strong (h00/0k0) diffractions and grow with a heteroepitaxial relationship to the underlying Nb:TiO2 substrates. The BNT-0.75 film deposited on a Nb:TiO2(101) substrate with 0.79 mass% Nb exhibited the peculiar shape of approximately 100- to 150-nm-thick nanoplates. We speculate that the driving force for producing a plate-like structure for BNT films is the large anisotropy of the linear expansion coefficients for Bi4Ti3O12, and the comparatively small lattice matching between the Nb:TiO2 substrate and the BNT film.

BiFeO3 (BFO) thin films with various Bi/Fe ratios have been deposited on SrRuO3/SrTiO3/SrTiO3(001) substrates by dual ion beam sputtering. A Bi2O3 ceramic disk and an α-Fe2O3 powder disk were used as targets, and simultaneously sputtered using a dual ion beam. Bi/Fe ratio has been controlled by adjusting the beam current ratio on the Bi2O 3- and α-Fe2O3-side ion sources. Even a BFO thin film with a Bi/Fe ratio of 0.95 and a smooth surface shows a slightly leaky characteristic. [Fe2+]/(Fe3+]+ [Fe2+]) ratio has been estimated by Auger electron spectroscopy (AES). From the AES profiles, the [Fe2+]/(Fe3+]+ [Fe2+]) ratio of the BFO thin film with a Bi/Fe ratio of 0.95 is estimated to be 0.14. It is considered that not only improving surface roughness but also enhancing oxidization is important for reduction in leakage current. © 2011 The Japan Society of Applied Physics.

Adsorbents for removing cadmium ions from water were synthesized from inorganic wastes such as oyster shells, drinking-water-treatment sludge (DWTS), and waste glass. The oyster shells and DWTS were pretreated by heating for 2 h at 1173 K before hydrothermal synthesis was started. The Al/(Al+Si) ratio was adjusted, and then, the mixture of pretreated materials was hydrothermally treated in a sodium hydroxide solution for 72 h at 423 K to synthesize the adsorbents. The synthesized adsorbent specimens were characterized by X-ray diffraction (XRD), thermogravimetric-differential thermal analysis (TG-DTA) measurements, and scanning electron microscopy (SEM). The main components of these specimens were aluminum-substituted tobermorite and sodalite. The formation of sodalite was dependent on the mass ratio of DWTS to glass. The maximum amount of cadmium ions were removed when the mass ratio of the pretreated material was 1:1:1. In the cadmium removal test, the adsorbent with this mass ratio removed almost 100% of the cadmium in a solution with a concentration of 10 mg L-1. Even in the presence of a 1000-fold excess of potassium ions or 10000-fold excess of sodium ions, approximately 80% of the cadmium ions were removed.

Adsorbents for removing cadmium ions from water were synthesized from inorganic wastes such as oyster shells, drinking-water-treatment sludge (DWTS), and waste glass. The oyster shells and DWTS were pretreated by heating for 2 h at 1173 K before hydrothermal synthesis was started. The Al/(Al+Si) ratio was adjusted, and then, the mixture of pretreated materials was hydrothermally treated in a sodium hydroxide solution for 72 h at 423 K to synthesize the adsorbents. The synthesized adsorbent specimens were characterized by X-ray diffraction (XRD), thermogravimetric-differential thermal analysis (TG-DTA) measurements, and scanning electron microscopy (SEM). The main components of these specimens were aluminum-substituted tobermorite and sodalite. The formation of sodalite was dependent on the mass ratio of DWTS to glass. The maximum amount of cadmium ions were removed when the mass ratio of the pretreated material was 1:1:1. In the cadmium removal test, the adsorbent with this mass ratio removed almost 100% of the cadmium in a solution with a concentration of 10 mg L-1. Even in the presence of a 1000-fold excess of potassium ions or 10000-fold excess of sodium ions, approximately 80% of the cadmium ions were removed. © 2011 Ceramic Society of Japan..

カキ殻が持つ特長を活かしながら，低コストで環境負荷イオンを効率よく除去するための処理法確立を目的として，カキ殻の熱処理条件について検討した。<BR>適切な窒素ガス流量で焼成すれば1気圧での炭酸カルシウムの分解温度である900℃よりもはるかに低い600℃でカキ殻表面の改質ができ，リン酸イオンや硫酸イオンおよびカドミウムイオンを効率よく除去できることを明らかにした。オゾンや空気雰囲気では600℃で熱処理した場合にリン酸イオン除去率の低下が見られた。熱処理カキ殻によるイオン除去性は高い順にカドミウムイオン，リン酸イオン，硫酸イオンであった。

The distribution of lead (Pb) accumulated ill the pteridophyte Blechnum niponicum, a Pb-hyperaccumulator, was measured using synchrotron-radiation micro X-ray fluorescence (SR-mu-XRF) at BL37XU of SPring-8. From two-dimensional (2D) imagings of Pb at the root, petiole, leaf vein, pinna epidermis and sorus in the Blechnum niponicum, the mechanism for the transportation and accumulation of Pb can be suggested to be as follows: Lead is accumulated in conductive tissues. Most of the Pb solubilized in the rhizosphere is fixed in the conductive tissue, with the remainder being transported with the transpiration stream to the above-ground parts of the plant. Lead transported to the upper parts of the plant ultimately remains at the terminal points of the transpiration stream, including the stomatal apparatus and water pores; it was shown that these sections contain high concentrations of Pb.

High-density ceramics with compositions of (Bi0.5-xNa 0.5TiO3)0.06 (BaTiO3)0.06 (BNBT-6), where x = 0-0.03, were fabricated to develop potentially useful lead-free piezoelectric materials with high mechanical quality factors, Q m. Effects of Bi-deficiency on the physical properties of the fabricated ceramics were investigated. Microstructures of the samples with a Bi-deficiency of x≥0.015 showed no appreciable grain boundaries. This is due to the liquid-phase sintering that occurs for a Bi-deficiency concentration of x≥0.015. The mechanical quality factors for the radial vibration mode and the thickness vibration mode exhibited a maxima at x=0.022 and 0.024 with values of 674 and 128, respectively. The temperature coefficients of resonant and antiresonant frequencies (TCF) of the BNBT-6 samples with x=0.019-0.030 were almost constant with TCFfr1=-400ppm/°C for the fundamental resonant frequency and TCFfa1 =-320ppm/°C for the fundamental antiresonant frequency, respectively. This method of creating a deficiency of a very small quantity of Bi in the BNBT-6 composition produces substantial improvement in Qm characteristics without deterioration of other piezoelectric parameters.

The morphotropic phase boundary (MPB) for the PMNZT series of high-density ceramics (xPb(Mg-1/3 Nb-2/3) O-3-yPbZrO(3)-zPbTiO(3); x = 0.1-0.2, y = 0.400-0.486, z = 0.395-0.477) is relocated based on analyses of the dielectric, piezoelectric and ferroelectric properties of incremental compositions. The PMNZT ceramics, fabricated by the columbite route, exhibit a single-phase perovskite structure. The refined MPB line is shifted toward the PbTiO3 (PT) side in the ternary field by approximately 2.4 mol% from the position reported in the literature and the pinpoint composition for piezoelectric applications is further shifted toward the PT side by approximately 1.2 mol% from the obtained MPB line. The PMNZT 14.2/41.6/44.2 (100x/100y/100z) composition near the MPB line is shown to have properties suitable for practical applications.

The inorphotropic phase boundary (MPB) for the PMNZT series of high-density ceramics (xPb(Mg1/3 Nb2/3)O3-yPbZrO 3-zPbTiO3; x= 0.1-0.2, y = 0.400-0.486, z = 0.395-0.477) is relocated based on analyses of the dielectric, piezoelectric and ferroelectric properties of incremental compositions. The PMNZT ceramics, fabricated by the columbite route, exhibit a single-phase perovskite structure. The refined MPB line is shifted toward the PbTiO3 (PT) side in the ternary field by approximately 2.4 mol% from the position reported in the literature and the pinpoint composition for piezoelectric applications is further shifted toward the PT side by approximately 1.2 mol% from the obtained MPB line. The PMNZT 14.2/41.6/44.2 (100x/100y/100z) composition near the MPB line is shown to have properties suitable for practical applications.

The morphotropic phase boundary (MPB) for the PMNZT series of high-density ceramics (xPb(Mg1/3Nb2/3)O3-yPbZrO 3-zPbTiO3; x = 0.1-0.2, y = 0.400-0.486, z = 0.395-0.477) is relocated based on analyses of the dielectric, piezoelectric and ferroelectric properties of incremental compositions. The PMNZT ceramics, fabricated by the columbite route, exhibit a single-phase perovskite structure. The refined MPB line is shifted toward the PbTiO3 side in the ternary field by approximately 3.6 mol% from the position reported in the literature. The PMNZT 14.2/41.6/44.2 (100x/100y/100z) composition on the MPB line is shown to have properties suitable for practical applications.

シダ植物の重金属含有量を調べるために, 兵庫県内7地域に自生するシダ133試料を採取した.蛍光X線分析法および原子吸光分析法を用いて測定した結果, 以下の事実を得た.<BR>1) ウラジロ科のコシダやウラジロはいずれもマンガンについて比較的高いX線強度が得られた.<BR>2) S1地域において採取したシシガシラには数千ppmの鉛が含有されていた.<BR>3) シシガシラにおける鉛含有量は根茎, 根および葉身の順に高かった.

Alkylphenols are used as raw material of alkylphenol polyethoxylate-type non-ionic surfactant and these substances exist most widely in environmental water. Recently, these substances are known as endocrine disruptors. We collected water sediment, blue mussel and plankton samples in Harimanada which is located in the Seto Inland Sea; Hyogo, Japan. Nonylphenol(NP) in the all samples were determined by gas chromatography/mass spectrometry. The behavior of nonylphenol in water environments was discussed.

化学処理した茶葉を吸着剤として使用し, 水中の金属イオンの捕集能について検討した結果, 以下の結果を得た.<BR>(1) 70から100メッシュに粉砕した茶葉をホルマリンとリン酸 (0.1M) を用いて80℃で処理すると, 吸着剤が調製できる.この吸着剤は未処理の茶葉に比べて約4倍の金属イオン捕集能力を示す.<BR>(2) 煎茶, 紅茶, ウーロン茶について検討した結果, 茶葉の種類による差はあまり見られず, 煮出したあとの茶葉でも本吸着剤の原料となることが分かった.<BR>(3) 試料溶液のpHを5に調整し, 0.1gの吸着剤を用いると100μgまでの希土類金属イオン, ニッケルイオンおよびクロム (III) イオンが90%以上捕集可能である.<BR>(4) 本吸着剤単位量あたりの最大捕集量はニッケルで7.97mg, ネオジムでは5.91mgであった.

水中のアンモニウムイオンをフローインジェクション法により定量する方法について検討した.<BR>蒸留水はキャリアー流として1ml/minの流速で送液され, これに100μlの試料溶液を注入する.1.2%水酸化ナトリウム水溶液と4%チモール溶液も1ml/minの流速で試薬流として送液され, 反応コイル (5m, 80℃) 中でインドフェノール型化合物が生成する.この吸光度を676nmで測定する.検量線の直線性は良好で (r=0.9997) , 5mg/lのアンモニウムイオンの10回の繰り返し注入における相対標準偏差は0.62%であった.本法によって1時間当たり60試料の分析が可能である.

5種類のPAH (ベンゾ[a]ピレン、ペリレン、フルオランテン、ピレン、およびクリセン) の濃度を10^-2～10^-1μgcm^-3の範囲で種々変化させたn―ヘキサン溶液の蛍光スペクトル (Ex : 305nm, Em : 330～520nm) をアスキー形式のデータセットに変換した後マイクロコンピュータに読み込みPLS (Partial Least Squares) 回帰分析法を用いて回帰モデルを構築した。別に作成した濃度既知の合成試料溶液の蛍光スペクトルに回帰モデルを適用し、5種類のPAHについて計算して得られた予測値と良い一致を見た。

水中のセレン (IV) をフローインジェクション法により定量する方法について検討した.<BR>蒸留水はキャリアー流としては0.78ml/minの流速で送液され, これに200μlの試料溶液を注入する.4, 5-ジメチル-o-フェニレンジアミン溶液も0.78ml/minの流速で試薬流として送液され, 反応コイル (5m, 80℃) 中で4, 5-ジメチルピアセレノールが生成する.このピアセレノールの吸光度を340nmで測定する.検量線の直線性は良好で (r=0.9999) , 5mg/l及び10mg/lのセレンの10回の繰り返し注入における相対標準偏差はそれぞれ0.26及び0.32%であった.本法によって1時間当たり40試料の分析が可能である.本法は感度の点で排水中のセレンを直接定量するのは困難であると思われる.したがって, 試料がppmレベル以下のセレンを含む場合や数種の妨害イオンを含む場合には共沈のような適当な予備濃縮操作が必要であると考えられる.

A highly selective spectrophotometric method is described for the determination of palladium, using 3-thiophenaldehyde-4-phenyl-3-thiosemicarbazone (TAPS). The method is based on the formation of an insoluble palladium(II)-TAPS complex, which is extractable into chloroform from 1 M sulfuric acid medium after shaking for 10 min. The complex system conforms to Beer's law over the concentration range 0.4-6 mug ml-1 of palladium. The proposed method has been satisfactorily applied to the determination of palladium in brazing filler metals. (C) 1994 Academic Press, Inc.

本法ではキャリアー, 試薬溶液 (2%アルフッソン溶液) の流速を共に1.42ml/minに設定し, 測定波長を640nm, 試料注入量を200μl, 反応コイル長を3.5mとした条件で, 1時間当り40試料の分析が可能であった. また, フッ化物イオン濃度5mg/lの試料を10回繰り返し注入して得られた変動係数は0.40%であった, 標準添加法により海水中のフッ化物イオンの定量を行い,良好な結果を得た.

水中のクロロホルムをフローインジェクション法により定量する方法について検討した.本法は以下の2つの反応に基づいている.<BR>(1) Reimer-Tiemann反応, これはフェノールがアルカリ溶液中でクロロホルムと反応してサリチルアルデヒドを生成する反応として知られている.<BR>(2) サリチルアルデヒドとエチレンジアミンより形成されるシッフ塩基とベリリウムから成る錯体の生成<BR>5%のフェノールと4%の水酸化ナトリウムを含むキャリアー流は0.58ml/minの流速で送液され, これに125μlの試料溶液を注入する.これより, 加熱コイル (5m, 85℃) 中でサリチルアルデヒドが生成し, これは0.35ml/minの流速で送液される試薬流中のエチレンジァミン及びベリリウムと冷却コイル (2m, ℃) において反応し, ベリリウムーシップ塩基錯体を生成する.340nmで励起したこの錯体の蛍光強度を440nmで測定する.検量線の直線性は良好で, 5mg/lのクロロホルムの5回の繰り返し注入における相対標準偏差は0.80%であった.本法によって1時間当たり15試料の分析が可能である.本法は感度の点で飲料水中のクロロホルムの定量には適用できないが, ppmレベルのクロロホルムを含む試料のモニタリングには有用と考えられる.

EABとCTMAを併用する水中のマグネシウムのフローインジェクション-吸光光度定量について検討し, 次の結果を得た.<BR>1) PTFEチューブの内径を0.50mm, キャリアー溶液 (pH11, CTMA2×10^-3M) の流速を0.71ml/min, 試薬溶液 (EAB 0.10%in CH₃0H) の流速を0.30ml/min, 混合コイルの長さを50cmとした場合のフローインジェクション分析システムに125μlの試料を注入することにより, 半自動的にマグネシウムの分析が行える.<BR>2) 検量線は良好な直線関係を示し, マグネシウム濃度1.0と0.5mg/lにおける5回の繰り返し注入による相対標準偏差はそれぞれ0.79および0.85%であった.<BR>3) 本法における1時間当りの分析数は60検体であった.<BR>4) 本法はカルシウムの影響を受けるため, 実試料の分析に際しては, カルシウム濃度が2mg/l以下になるように適宜希釈する必要がある.<BR>5) 本法により河川水中のマグネシウムを定量した結果, 原子吸光分析法とよく一致した.

水中のセレン (IV) をニッケルーDDTC錯体に共沈捕集し, これを蛍光X線分析により定量する方法について検討した.セレンを含む検水に100mg/lのニッケル共沈剤溶液15ml及び5%フタル酸水素カリウム緩衝剤溶液10mlを加える.検水のpHを4に調整した後, 2%DDTC沈澱剤溶液5mlを添加し, 30分間放置して沈澱を熟成させる.沈澱を0.45μmのメンブランフィルター上に捕集し, 風乾後蛍光X線分析を行った.本法による水中のセレンの共沈率は97%以上であった.0～10μg/lの濃度範囲で測定した検量線は良好な直線性を示し, 検水1, 000mlを用いた場合の本法の定量下限は1.9μg/lであった.本法をガラス工場の排水分析に適用した結果, 5.1μg/lのセレンが検出され, JIS法による結果5.0μg/lとよく一致した.

共沈濃縮法を用いる海水中のニッケルの黒鉛炉原子吸光分析について検討を行い, つぎの結果を得た.<BR>(1) 検水に鉄 (II) 共沈剤1mgを添加した後pHを7に調整し, DDTC沈殿剤0.1gを加えて30分間攪拌今れば100～1,000mlの検水中に溶存する微量のニッケルは定量的に共沈する.<BR>(2) 共沈濃縮して得られた沈殿を硝酸 (1+12) 30mlを用いて30分間加熱攪拌することにより, ニッケルは完全に溶出し, この溶液を蒸発乾固したとち, 硝酸(1+25) 10mlを加えて再溶解するこのにより, GFAAS用の検液として使用できる.<BR>(3) 50倍濃縮を行った場合の検出限界および定量下限はそれぞれ0.5と1.6μg/lであった.<BR>(4) 本法は海水中の共存物質による妨害を受けることなく微量のニッケルを共沈捕集できる.<BR>(5) 数回の繰返し実験を行い, その平均値から検量線式にしたがって求めると海水中の1～2μg/l程度のニッケルも検量線法で十分定量できる.

共沈濃縮-黒鉛炉原子吸光分析法を用いる海水中の銅の定量について検討を行い, 次の結果を得た.<BR>(1) アルミニウム共沈剤1mgとDDTC沈殿剤0.1gを用いるとpH7で100～1,000mlの検水中に溶存する微量の銅は定量的に共沈する.<BR>(2) 共沈濃縮して得られた沈殿を硝酸 (1+12) を用いて加熱分解することにより, 銅は完全に溶出し, 黒鉛炉原子吸光分析用の検液として使用できる.<BR>(3) 5倍濃縮を行った場合の検出限界および定量下限はそれぞれ3と10μg/lであった.<BR>(4) 50倍濃縮を行った場合の検出限界および定量下限はそれぞれ0.7と2.4μg/lであった.<BR>(5) 海水中の銅の定量に本法が十分利用できることがわかった.

水中の8種の重金属 (クロム, マンガン, 鉄, コバルト, ニッケル, 銅, 亜鉛, 及び鉛) をDDTC沈殿剤とチタン共沈剤を用いてpH10で共沈濃縮し, これをチャートレコーディング法を用いる蛍光X線分析により同時定量する方法について検討した.鉛の測定にはLa線のピークを使用し, 他の金属についてはKα線のピークを用い, 各々の高さから定量を行った.これらの重金属イオンの共沈率は約90%以上であった.<BR>0.01～1.0mg/lの濃度範囲で測定した検量線は良好な直線性を示した.海水を用いて調製した検水についても検討したところ, 海水中ではコバルト (II) イオンの共沈が著しく妨害されたが, 他の重金属イオンは海水中でも良好な共沈率を示した.

炭酸バリウム共沈法を用いる環境水中のストロンチウムの蛍光X線分析法について検討を行い, 次の結果を得た.<BR>(1) 検水に塩化バリウム溶液 (2gBa/l) 25mlおよび炭酸ナトリウム溶液 (5w/v%) 20mlを添加し, 1時間攪拌熟成すると, ストロンチウムは定量的に共沈する.<BR>(2) 検量線は良好な直線関係を示し, 相対標準偏差は3%以下で, 分析精度も良好である.<BR>(3) 本法の検出限界は0.3μgで, 定量下限は1.1μgである.<BR>(4) 多量のカルシウムイオンの共存はストロンチウムイオンの共沈を妨害するが, 共存量が2mg以下であれば妨害は認められない.<BR>(5) マグネシウムイオンの共存もストロンチウムイオンの共沈を妨害するが, 共存量が10mg以下であれば妨害は認められない.<BR>(6) 海水, 河川水等の環境水中のストロンチウムイオンが, 検量線法で精度よく定量できることがわかった.