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ID 52410
フルテキストURL
著者
Higashidani, Naoki Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University
Kaneta, Takashi Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University ORCID Kaken ID
Takeyasu, Nobuyuki Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University
Motomizu, Shoji Okayama University
Okibe, Naoko Department of Earth Resources Engineering, Graduate School of Engineering, Kyushu University
Sasaki, Keiko Department of Earth Resources Engineering, Graduate School of Engineering, Kyushu University
抄録
The thermoacidophilic iron-oxidizing archaeon Acidianus brierleyi is a microorganism that could be useful in the removal of inorganic As from wastewater, because it simultaneously oxidizes As(III) and Fe(II) to As(V) and Fe(III) in an acidic culture medium, resulting in the immobilization of As(V) as FeAsO4. To investigate the oxidation mechanism, speciation of the As species in both the cells and its culture media is an important issue. Here we describe the successive determination of As(III), As(V), and total As in A. brierleyi and its culture medium via a facile method based on inductively coupled plasma–optical emission spectroscopy (ICP–OES) with a flow injection pretreatment system using a mini-column packed with an anion-exchange resin. The flow-injection pretreatment system consisted of a syringe pump, a selection valve, and a switching valve, which were controlled by a personal computer. Sample solutions with the pH adjusted to 5 were flowed into the mini-column to retain the anionic As(V), whereas As(III) was introduced into ICP–OES with no adsorption on the mini-column due to its electrically neutral form. An acidic solution (1 M HNO3) was then flowed into the mini-column to elute As(V) followed by ICP–OES measurement. The same sample was also subjected to ICP–OES without being passed through the mini-column in order to determine the total amounts of As(III) and As(V). The method was verified by comparing the results of the total As with the sum of As(III) and As(V). The calibration curves showed good linearity with limits of detection of 158, 86, and 211 ppb for As(III), As(V), and total As, respectively. The method was successfully applicable to the determination of the As species contained in the pellets of A. brierleyi and their culture media. The results suggested that the oxidation of As(III) was influenced by the presence of Fe(II) in the culture medium, i.e., Fe(II) enhanced the oxidation of As(III) in A. brierleyi. In addition, we found that no soluble As species was contained in the cell pellets and more than 60% of the As(III) in the culture medium was oxidized by A. brierleyi after a 6-day incubation.
キーワード
Thermoacidophilic iron-oxidizing archaeon
Acidianus brierleyi
Arsenic
Speciation
Inductively coupled plasma–optical emission spectroscopy
Flow injection pretreatment
発行日
2014-05
出版物タイトル
Talanta
122巻
出版者
Elsevier
開始ページ
240
終了ページ
245
ISSN
00399140
NCID
AA00856594
資料タイプ
学術雑誌論文
言語
English
OAI-PMH Set
岡山大学
著作権者
© 2014 Elsevier B.V. All rights reserved
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関連URL
isVersionOf https://doi.org/10.1016/j.talanta.2014.01.057