誘導結合プラズマ発光分析法を利用して亜ヒ酸に含まれる微量不純物の多元素同時定量を行い, 分析値の比較による異同識別を試みた. 亜ヒ酸約250mgを精ひょうした後ビーカーに採取し, 濃塩酸5mlを加えて加熱した. これに濃硝酸0.5mlを滴下して穏やかに加熱し, 亜ヒ酸を完全に溶解させた後, 純水で25mlに希釈して測定用試料溶液を調製した. 不純物元素の定量には, 試料溶液と酸濃度が等しくなるように調製した, 多元素混合標準溶液を検量線として用いた. 本法の検出下限値は0.3～1.3μg/gであり, 市販亜ヒ酸中に15～120μg/g程度含まれるSe, Sn, Sb, Pb及びBiの5元素を, RSD5.5～0.9%の精度で定量することが可能であった. 本法によるSb及びPbの定量値は, JIS法で前処理を行った場合と良好な一致を示した. 本法を由来の異なる亜ヒ酸14点の分析に応用した結果, 同一試料内での分析値の変動は異なる試料間の差異と比較して十分に小さく, 分析値の比較は亜ヒ酸相互の異同識別に有効であった.

抄録全体を表示

既存の陽イオン交換型サプレッサを金属除去デバイスとして利用し，サプレスト方式イオンクロマトグラフ（IC）とインラインで組み合わせることで金属イオン含有試料中の微量Cl^－測定の前処理から測定までを全自動で行えるシステムを構築した．まず，金属除去デバイスによる金属イオン除去効率を評価し，400 mg L^－1の銅が添加された溶液で問題なく測定できることを確認した．次いで，インライン金属除去デバイス─ICシステムの精度検証を，金属イオン含有溶液を使って行った．さらに，本システムの適用例として，金属塩試薬やエッチング液中の微量Cl^－の測定を行ったところ，1 mg kg^－1以下の塩化物イオンの定量が可能であった．

抄録全体を表示

新しい原子発光分析である液体電極プラズマ法（LEP-AES法）は，中央が絞られた小型容器（横幅数mm）に数十μLの試料を入れ，そこに高電圧を印加する事でマイクロプラズマを発生させる方式である．ICP-AES法と異なり，アルゴンガスや大電力を必要としないため，小型化並びに可搬化が可能となり，本法を応用したハンディ元素分析装置が開発された．本研究では，認証汚染土壌に含有されているPbをハンディ元素分析装置で測定する事を目的として，装置の性能評価を行った．結果は波長405.8 nmにおける検出限界が1.3 mg/L，相対標準偏差（RSD）は10％ 以下，直線性許容範囲は2桁と，ハンディ元素分析装置としては十分な性能であった．汚染土壌は環境省告示第19号に準拠した方法で溶出液を作成し，固相抽出により分離濃縮後，測定を行った．測定結果は80.2 mg/kg（dry）であり，認証値82.7±3.8 mg/kg（dry）の許容範囲内の値であった．

抄録全体を表示

高純度硫酸ガドリニウム中の超微量トリウム及びウランを定量するための分離・濃縮法として，トリウムはキレート樹脂を用いた分離法を，ウランは陰イオン交換樹脂を用いた分離法を検討した．トリウムは，塩酸で溶解した溶液をpH 2に調整し，エチレンジアミン三酢酸を官能基に持つキレート樹脂を充填したカラムに通液した．ウランは，超純水で溶解した溶液をpH 2に調整し，陰イオン交換樹脂を充填したカラムに通液し，それぞれ主成分のガドリニウムから分離した．樹脂に捕捉したトリウム及びウランは塩酸溶液を用いて溶離し，ICP質量分析装置にて分析した．本法をスーパーカミオカンデの新規水チェレンコフ検出器での使用が予定されている高純度硫酸ガドリニウムの評価法として適用するために，その試料に対して分析を実施したところ，定量下限はトリウムが1 pg g⁻¹，ウランが4 pg g⁻¹であった．また，両者とも回収率は95％〜105％ であり，またガドリニウムの除去率は99.97％ 以上であった．

抄録全体を表示

ボイラ給水中の鉄分析方法（JIS B 8224.32）である2,4,6-トリ（2-ピリジル）-1,3,5-トリアジン吸光光度法（以下，加熱濃縮─TPTZ法）の前処理方法として，メンブレンフィルターとイミノ二酢酸型キレートフィルターを併用した2段フィルター濃縮法（以下，フィルター濃縮法）を開発した．水処理方式として酸素処理法（CWT: 複合水処理）が多く採用される超々臨界圧ボイラでは，プラント運転不具合防止のために給水中鉄濃度を2 μg L^－1以下と厳しく管理することが求められる．CWT適用ボイラの給水中に含まれる鉄の大部分は固体であるヘマタイト（α – Fe₂O₃）として存在していることから，メンブレンフィルターで粒子状鉄を，キレートフィルターで残存する溶存鉄を捕集する手法により，現場において迅速に高倍率で試料を濃縮することができる．開発した方法をCWT運用超々臨界圧ボイラの各系統の鉄濃度分析に適用した結果，従来では評価が困難であった低濃度域を精度よく分析することができ，分析時間の短縮も図れることから現場に適した手法であることを実証した．

抄録全体を表示

The application of trace element analysis using ICP-MS was investigated for the forensic discrimination of charcoal samples. Eleven kinds of commercially available charcoal samples were collected and used for the experiments. A small amount of each charcoal was burned in an electrical furnace to make ash. Approximately 5 mg of ash was sonicated with a mixture acid of 250 μL of nitric acid, 250 μL of hydrochloric acid and 500 μL of hydrofluoric acid, followed by heating to dryness. The residue was dissolved again in 500 μL nitric acid, and diluted to 10 mL to prepare sample solutions. Qualitative analysis of the sample solution using ICP-MS indicated that charcoal ash contained elements such as Mn, Fe, Cu, Zn, Rb, Sr, Ba, La, Ce, Nd, Pb. Four trace elements (La, Ce, Nd, Pb) were selected for the determination, and a comparison for the discrimination of different ash samples. Ash made from different charcoals tend to exhibit larger difference in the concentration of these elements than the variation within a sample. The ranges of the mean±2 SD for each element were compared for all of 55 pairs among 11 different ash samples. The combination of 4 elements allowed for the discrimination of all possible pairs, although no single element could achieve complete discrimination. The analysis and comparison of trace elements by the present method was quite effective for the forensic discrimination of charcoal ashes.

抄録全体を表示

We present herewith a report on an investigation concerning the "Special Medical Examination on the Mercury Group" with cooperations of 429 workers in a clinical thermometer manufacturing factory. In the screening test, we placed great emphasis on the symptoms, among which loss of weight, oral appearance, albuminuria, sediments of urine, tremor, llong continuous headache, and insomnia were particularly worthy of special attention. In conducting detailed examinations, on the other hand, special emphasis was placed on the appearance of the specific symptoms of mercury intoxication and its progress, along with mercury quantity in the urine, general features of the urine and the blood, functions of the kidney, and serum protein fraction. The final analysis of the above examinations revealed the following facts. 1. Next to the general symptoms, change of the oral appearance occurs at an early stage. 2. Mercury quantity in the urine does not conform to the clinical symptoms. We should, however, attach much importance to the findings in urine as considered from the progress of the disease. 3. Functional disorders in the liver were not observed. 4. Significant results by on the serum protein test were not recognized.

抄録全体を表示

This paper describes the application of trace elemental analysis using ICP-AES and ICP-MS to criminal investigation. The comparison of trace elements, such as Rb, Sr, Zr, and so on, is effective for the forensic discrimination of glass fragments, which can be important physical evidence for connecting a suspect to a crime scene or to a victim. This procedure can be applied also to lead shotgun pellets by the removal of matrix lead as the sulfate precipitate after the dissolution of a pellet sample. The determination of a toxic element in bio-logical samples is required to prove that a victim ingested this element. Arsenous acids produced in Japan, China, Germany and Switzerland show characteristic patterns of trace elements characteristic to each country.

抄録全体を表示

Ueda and his co-workers have recently reported that thioctic (TA) (lipoic acid), especially dihydro-thioctic acid (DTA) combined with mercury in vitro to form a non-toxic substance, and later Ishii and Shimizu proved their detoxicating effect by animal experiment. But in the field experiments with workers in aclinical thermometer factory and with other operators exposed to mercury, the distinct promotion of mercury excretion in urine was hardly observed as Shimizu's paper reported. From these results it became necessary to reinvestigate the detoxicating effect of TA by more detailed experiments. Part 1: Effect on urinary mercury excretion in rabbits. Rabbits were injected intramusc. 0.2mg/kg of mercury (as HgCl₂) for twelve days, and then BAL (dimercaptol-propanol) or OTA in peanut oil was injected for three succesive days. In the BAL group the mercury excretion in urine was promptly increased three to five times, whereas in the DTA group the increase was only one and a half to two times of that in the pre-experimental period. Mono-thiol agents were also investigated and L-cysteine and DL-penicillamin showed promoting effects as excellent as BAL. The ineffectiveness of DTA on the mercury excretion in urine might be understood if the resultant compound in the body for a long time due to its poor solubility. To assertain this point, SS'-mercuri-TA was prepared in vitro and injected to rabbits intramusc. The result was in support of the author's assumption, and no increase of mercury excretion was observed during a week. Part 2: Effect of dithiol-agents on the growth of rats poisoned with mercury. (a) A dilute solution of mercuric nitrate (Hg 30ppm) was given to rats ad lib. from water bottles through 30 days. The antidote was injected intramusc. dalily. The growth curve of DTA group (10mg/kg) was as good as BAL group (6mg/kg), but both were inferior to the healthy control. In the case of high mercury dosing (100 ppm) DTA could show a remarkable detoxicating effect whereas TA could not support the growth after 18 days. (b) The previous experiment had rather a prophylactic nature because the detoxicant and poison were given simultaneously from the start. In order to investigate the therapeutic effect, the rats were first poisoned with 250ppm mercury for ten days. The animal lost the weight drastically reaching the initial level of two weeks before. Then BAL or DTA was given intramusc. daily. The recovery was dramatical and the growth rate was practically equal in these two antidotes. (c) The organ-body weight ratio of liver and kidney was investigated in the experiment (a) mentioned above. The BAL group showed hardly any difference in the ratios compared with the control, but in DTA and non-treated groups the ratios were significantly higher than the control, indicating the enlargement of organs. (d) The brain, liver and kidney of rats in the experiment (a) were assayed for the mercury content. The BAL group was excellent only one to one and a half times of mercury being found as compared with that of the healthy control. DTA group was also good though slightly inferior to BAL group and only one-fourth of mercury deposit was found compared with the non-treated group. These results indicated the gradual transportation and excretion of SS'-mercuri-TA in spite of its poor solubility in body fluid. As for the route of excretion, the possibility through the digestive tract including the biliary might be considered as suggested in the previous paper of Shimizu using S³⁵-TA in experimental mercury poisoning. Conclusion; DTA was able to detoxicate mercury in the experimental chronic poisoning in rats and rabbits. As the resultant product is insoluble in water, the prompt increase of urinary excretion of mercury is hardly expected. This is the difference from other thiol-agents and the evaluation of effects by the urinary assay will be misleading in this instance.

抄録全体を表示

An analytical method for the detection of cadmium in sea water samples by using Inductively Coupled Plasma Mass Spectrometry with a chelating resin solid-phase extraction (SPE) method was developed. The MCM resin in a syringe-driven chelating column was investigated in the present experiment. Using this resin, Cd and Mo were preconcentrated at pH 3.5; further, matrix elements such as Na, K, Mg and Ca were removed under the same conditions. In other words, under pH conditions over 10, Mo is eluted though Cd is maintained. It was shown that the separation of Cd and Mo could be obtained. Using this method, it was possible to analyze under ng L⁻¹ Cd without interferences from Mo. The present method was validated by analyzing five certified reference materials, and then the vertical distribution of Cd concentration in the sea water around Japan Island was obtained.

抄録全体を表示