著者

工藤 清孝 山本 桂子 谷口 明男 久保 淳二朗 佐野 香代子

出版者

無機マテリアル学会

雑誌

無機マテリアル (ISSN:2185436X)

巻号頁・発行日

vol.6, no.283, pp.492-496, 1999-11-01 (Released:2011-03-07)

参考文献数

7

著者

小林 憲弘 小坂 浩司 浅見 真理 中川 慎也 木下 輝昭 高木 総吉 中島 孝江 古川 浩司 中村 弘揮 工藤 清惣 粕谷 智浩 土屋 かおり 寺中 郁夫 若月 紀代子 加登 優樹 小関 栄一郎 井上 智 村上 真一 金田 智 関 桂子 北本 靖子 堀池 秀樹 米久保 淳 清水 尚登 髙原 玲華 齊藤 香織 五十嵐 良明

出版者

公益社団法人 日本水環境学会

雑誌

水環境学会誌 (ISSN:09168958)

巻号頁・発行日

vol.40, no.6, pp.223-233, 2017 (Released:2017-11-10)

参考文献数

23

被引用文献数

2 1

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水道水中の臭素酸イオン (BrO3-) を既存の告示法よりも高精度かつ迅速・簡便に分析するために, LC/MS/MSによる測定方法を検討し, 臭素酸イオンを高感度に検出でき, さらに水道水中に含まれる他の陰イオンを良好に分離可能な測定条件を確立した。さらに, 本研究で確立した測定条件が全国の水道水に適用できるかどうかを検証するために, 水道事業体等の23機関において水道水に臭素酸イオンを基準値 (0.01 mg L-1) およびその1/10 (0.001 mg L-1) となるように添加した試料を調製し, 各機関で最適化した様々な測定条件で試験を行った。その結果, いずれの機関においても厚生労働省が示している「水道水質検査方法の妥当性評価ガイドライン」の真度, 併行精度および室内精度の目標を満たしたことから, 本分析法は水道水中の臭素酸イオンを基準値の1/10 (0.001 mg L-1) まで高精度に分析可能であると評価した。

著者

黒田 正範 工藤 清勝

出版者

公益社団法人日本分析化学会

雑誌

分析化学 (ISSN:05251931)

巻号頁・発行日

vol.30, no.3, pp.174-178, 1981-03-05

被引用文献数

2

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薄層クロマトグラフィー(TLG)によるビスフェノールA系エポキシ樹脂の分離分析に及ぼす溶媒の極性と担体の粒度の影響を検討した.TLGで分離した各成分の基本構造式のnはゲル浸透クロマトグラフィー(GPC)により決定し,それぞれn=0からn = 7に対応することを確かめた.TLGの分離条件をグラジェント法による高速液体クロマトグラフィー(HPLC)に適用し,紫外部に吸収のないテトラヒドロフラン(THF)-クロロホルム系の吸着モードHPLCによりパターン分析ができることが分かった.

著者

野田 哲二 工藤 清勝 佐藤 教男

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.37, no.9, pp.951-957, 1973

被引用文献数

11

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The anodic passivation film formed on iron in neutral borate-buffer solution has been studied by using ellipsometric, electrochemical, and gravimetrical techniques. The film can be dissolved from its outer surface by applying a cathodic current in borate-buffer solution at pH 6.35 in which the reductive dissolution,<BR>(This article is not displayable. Please see full text pdf.) <BR>\oindentproceeds at 100 per cent current efficiency. Ellipsometric measurements carried out during the galvanostatic-cathodic reduction of the film in this solution reveals that the film consists of two layers, an inner layer with the optical constant 3.0&minus;0.5<I>i</I> and an outer layer with the constant 1.8&minus;0.1<I>i</I>. It is also shown that the density of the inner layer is in agreement with that of &gamma;-Fe<SUB>2</SUB>O<SUB>3</SUB>.<BR>The inner layer thickness increases linearly with the passivating potential, and the potential extrapolated at zero thickness of the inner layer corresponds to the equilibrium potential of the anodic formation of &gamma;-Fe<SUB>2</SUB>O<SUB>3</SUB>,<BR>(This article is not displayable. Please see full text pdf.) <BR>\oindentThe outer layer, however, is not directly related to the anode potential. <BR>Thermo-gravimetrical measurements indicate that the film contains some amount of water which is concentrated in the outer layer. The average composition of the outer layer is estimated as Fe(OH)<SUB>3</SUB>.<BR>A film model is proposed in which the inner layer of anhydrous &gamma;-Fe<SUB>2</SUB>O<SUB>3</SUB> is the cause of the potential drop in the film producing a field intensity of 5.6&times;10<SUP>6</SUP> V/cm and the outer layer of hydrous ferric oxide depends on the solution environment and passivation process.

著者

工藤 清勝 岡本 剛

出版者

社団法人日本材料学会

雑誌

材料 (ISSN:05145163)

巻号頁・発行日

vol.17, no.179, pp.656-666, 1968

被引用文献数

1

著者

工藤 清 島 昌秀 久米 康仁 生駒 太志 森 貞之 杉田 信之

出版者

The Japan Petroleum Institute

雑誌

石油学会誌 (ISSN:05824664)

巻号頁・発行日

vol.38, no.1, pp.40-47, 1995-01-01 (Released:2008-10-15)

参考文献数

13

被引用文献数

4 15

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高圧二酸化炭素下, ギ酸-炭酸アルカリ金属溶融塩中における2-ナフトエ酸塩のカルボキシル化反応を検討した。アルカリ金属種による反応性を調べた結果, セシウム塩系が最も高く, セシウム>ルビジウム>カリウムの順に低くなり, ナトリウムおよびリチウム塩系ではほとんど反応しなかった。ギ酸セシウム-炭酸セシウム溶融塩中, 400気圧, 380°C, セシウム2-ナフトエ酸塩のカルボキシル化反応ではナフタレンジカルボン酸塩およびトリカルボン酸塩が容易に得られ, ジカルボン酸塩中では2,6-ジカルボン酸が主生成物であった。この反応での生成物中の全カルボキシル基収率は不均化反応の値よりも大きく, しかもナフタレンの生成がほとんど見られず, 従来のヘンケル法と違った結果が得られた。そこで, この反応の生成物収率に及ぼす二酸化炭素圧力, 温度, および炭酸塩の添加量の効果を調べた。13Cで標識した二酸化炭素を用いた反応結果, 加圧二酸化炭素による直接カルボキシル化反応が進行していることが明らかとなり, その反応機構について考察を行った。

著者

野田 哲二 工藤 清勝 佐藤 教男

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.37, no.9, pp.951-957, 1973 (Released:2008-04-04)

参考文献数

22

被引用文献数

18 11

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The anodic passivation film formed on iron in neutral borate-buffer solution has been studied by using ellipsometric, electrochemical, and gravimetrical techniques. The film can be dissolved from its outer surface by applying a cathodic current in borate-buffer solution at pH 6.35 in which the reductive dissolution,(This article is not displayable. Please see full text pdf.) \ oindentproceeds at 100 per cent current efficiency. Ellipsometric measurements carried out during the galvanostatic-cathodic reduction of the film in this solution reveals that the film consists of two layers, an inner layer with the optical constant 3.0−0.5i and an outer layer with the constant 1.8−0.1i. It is also shown that the density of the inner layer is in agreement with that of γ-Fe2O3.The inner layer thickness increases linearly with the passivating potential, and the potential extrapolated at zero thickness of the inner layer corresponds to the equilibrium potential of the anodic formation of γ-Fe2O3,(This article is not displayable. Please see full text pdf.) \ oindentThe outer layer, however, is not directly related to the anode potential. Thermo-gravimetrical measurements indicate that the film contains some amount of water which is concentrated in the outer layer. The average composition of the outer layer is estimated as Fe(OH)3.A film model is proposed in which the inner layer of anhydrous γ-Fe2O3 is the cause of the potential drop in the film producing a field intensity of 5.6×106 V/cm and the outer layer of hydrous ferric oxide depends on the solution environment and passivation process.

著者

工藤 清勝 岡本 剛

出版者

公益社団法人 日本材料学会

雑誌

材料 (ISSN:05145163)

巻号頁・発行日

vol.17, no.179, pp.656-666, 1968-08-15 (Released:2009-06-03)

参考文献数

76

被引用文献数

2 1

著者

平澤 富士子 滝澤 行雄 山本 達雄 内田 眞志 栗原 靖夫 工藤 清孝 細野 恭平 藤井 正美

出版者

日本食品化学学会

雑誌

日本食品化学学会誌 (ISSN:13412094)

巻号頁・発行日

vol.2, no.1, pp.46-50, 1995-10-01

被引用文献数

1

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Silver-containing zeolite, which is natural or synthesized zeolite processed by ion exchange with silver, has an antimicrobial nature. Because of its long-lasting antibacterial activity, this substance is widely used as a plastic additive for structural parts of kitchen utensils, household electrical appliances, toilet seats and telephone handsets. With its antibacterial activity and character of filter medium, this substance is also suitable for use in simple water purification systems, and its practical use in this field is now being expected. Although silver-containing zeolite is non-carcinogenic, it has chronic toxicity, with the acceptable daily intake being calculated as 11 mg/kg・day for type A zeolite processed by silver-zinc-ammonium complex substitution. When used in water-purifying devices, silver-containing zeolite comes in direct contact with water. Therfore, serious attention from the viewpoint of public health should be paid to the possibility of elution of silver or other substituent factors and zeolite components. In this connection, we carried out elution tests of silver-containing zeolite itself, plastic products containing this type of zeolite as an additive and silver utensils. The amounts of cations of silver and other factors eluted from silver mordenite (Table 3), silver-ammonium mordenite (Table 4) and silver-zinc-ammonium type A zeolite (Table 5) immersed in 1L of water for 24 hours were determined. The types of water tested were purified water and tap water supplied in Tokyo, Osaka and Nagoya. The tap water varied in cation content according to the location (Table 2), with the total cation level being highest, 2.95 meq/L in Tokyo (Table 9). Elution of silver was always under the detection limit of 0.01 ppm, except that a trace amount of silver was detected with silver-containing mordenites immersed in the tap water of Tokyo. Zinc and ammonium were eluted increasingly, to a maximum concentration of 0.59 ppm and 5.2 ppm, respectively, as the total cation level in water increased. The mechanism of their elution was considered to be substitution by other cations present in tap water. There was not even any trace amout of eluted silver when zinc coexisted, suggesting that substiturion by inhibited the elution of silver. Concentrations of silica, aluminum and sodium in eluate were the same as those in original tap water, indicating that zeolite itself was not eluted. The allowable concentration of silver in tap water was set at 0.05 mg/L in the former Soviet Union. The corresponding standard for zinc is 1 mg/L in Japan. Elution of silver from plastic products with silver-containing zeolite and silver utensils was under the detection limit of 0.01 mg/L (Tables 6 and 7). There was also no elution of silver in tap water on flow tests (2L/min) (Table 8). Thus, silver was found to be firmly bound to zeolite in the silver-containing zeolite examined. Elution of silver was very slight if any, and was suggested to be related to the order of selectivity in ion exchange. The coexistence of harmless substituent cations which are at lower ranks in selectivity than silver seems to be effective for securely inhibiting the elution of silver.