start-ver=1.4
cd-journal=joma
no-vol=629
cd-vols=
no-issue=
article-no=
start-page=238
end-page=244
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2023
dt-pub=202301
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=Acidic layer-enhanced nanoconfinement of anions in cylindrical pore of single-walled carbon nanotube
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=The adsorption of the nitrate ion by the cylindrical pore of single-walled carbon nanotubes (SWCNT) was found to be aided by an acidic adsorbed layer. Adsorbed water in the vicinity of the pore wall can supply protons through ionization, forming the acidic layer, according to Raman spectra and results of solution pH fluctuations caused by ion species adsorption. Such an acidic adsorbed layer leads to surplus adsorption of anionic species where the adsorbed amount of nitrate ions is much larger than that of cations. Also, we could observe the Raman bands being assignable to the symmetrical stretching mode at an extremely highfrequency region for nano-restricted nitrate ions compared to any other bulk phases. The abnormal band shift of adsorbed nitrate ions indicates that the nitrate ions are confined in the pore under the effects of nanoconfinement by the pore and the strong interaction with the acidic layer in the pore. Our results warn that we have to construct the adsorption model of aqueous electrolytes confined in carbon pores by deliberating the acid layer formed by the adsorbed water.
en-copyright=
kn-copyright=

en-aut-name=OhkuboTakahiro
en-aut-sei=Ohkubo
en-aut-mei=Takahiro
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=1
ORCID=

en-aut-name=NakayasuHiroki
en-aut-sei=Nakayasu
en-aut-mei=Hiroki
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=2
ORCID=

en-aut-name=TakeuchiYuki
en-aut-sei=Takeuchi
en-aut-mei=Yuki
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=3
ORCID=

en-aut-name=TakeyasuNobuyuki
en-aut-sei=Takeyasu
en-aut-mei=Nobuyuki
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=4
ORCID=

en-aut-name=KurodaYasushige
en-aut-sei=Kuroda
en-aut-mei=Yasushige
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=5
ORCID=

affil-num=1
en-affil=Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University
kn-affil=

affil-num=2
en-affil=Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University
kn-affil=

affil-num=3
en-affil=Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University
kn-affil=

affil-num=4
en-affil=Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University
kn-affil=

affil-num=5
en-affil=Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University
kn-affil=
en-keyword=Proton
kn-keyword=Proton
en-keyword=Nitrate ion
kn-keyword=Nitrate ion
en-keyword=Adsorption
kn-keyword=Adsorption
en-keyword=Confinement
kn-keyword=Confinement
en-keyword=Micropore
kn-keyword=Micropore
en-keyword=Nanospace
kn-keyword=Nanospace
END

start-ver=1.4
cd-journal=joma
no-vol=122
cd-vols=
no-issue=
article-no=
start-page=240
end-page=245
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2014
dt-pub=201405
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=Speciation of arsenic in a thermoacidophilic iron-oxidizing archaeon, Acidianus brierleyi, and its culture medium by inductively coupled plasma–optical emission spectroscopy combined with flow injection pretreatment using an anion-exchange mini-column
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=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.
en-copyright=
kn-copyright=

en-aut-name=HigashidaniNaoki
en-aut-sei=Higashidani
en-aut-mei=Naoki
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=1
ORCID=

en-aut-name=KanetaTakashi
en-aut-sei=Kaneta
en-aut-mei=Takashi
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=2
ORCID=

en-aut-name=TakeyasuNobuyuki
en-aut-sei=Takeyasu
en-aut-mei=Nobuyuki
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=3
ORCID=

en-aut-name=MotomizuShoji
en-aut-sei=Motomizu
en-aut-mei=Shoji
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=4
ORCID=

en-aut-name=OkibeNaoko
en-aut-sei=Okibe
en-aut-mei=Naoko
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=5
ORCID=

en-aut-name=SasakiKeiko
en-aut-sei=Sasaki
en-aut-mei=Keiko
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=6
ORCID=

affil-num=1
en-affil=
kn-affil=Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University

affil-num=2
en-affil=
kn-affil=Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University

affil-num=3
en-affil=
kn-affil=Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University

affil-num=4
en-affil=
kn-affil=Okayama University

affil-num=5
en-affil=
kn-affil=Department of Earth Resources Engineering, Graduate School of Engineering, Kyushu University

affil-num=6
en-affil=
kn-affil=Department of Earth Resources Engineering, Graduate School of Engineering, Kyushu University
en-keyword=Thermoacidophilic iron-oxidizing archaeon
kn-keyword=Thermoacidophilic iron-oxidizing archaeon
en-keyword=Acidianus brierleyi
kn-keyword=Acidianus brierleyi
en-keyword=Arsenic
kn-keyword=Arsenic
en-keyword=Speciation
kn-keyword=Speciation
en-keyword=Inductively coupled plasma–optical emission spectroscopy
kn-keyword=Inductively coupled plasma–optical emission spectroscopy
en-keyword=Flow injection pretreatment
kn-keyword=Flow injection pretreatment
END

start-ver=1.4
cd-journal=joma
no-vol=1288
cd-vols=
no-issue=
article-no=
start-page=149
end-page=154
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2013
dt-pub=20130503
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=Determination of association constants between 5 '-guanosine monophosphate gel and aromatic compounds by capillary electrophoresis
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=Hydro gel formed by 5'-guanosine monophosphate (GMP) in the presence of a potassium ion is expected to exhibit interesting selectivity in capillary electrophoretic separations. Here, we estimated the conditional association constants between the hydro gel (G-gel) and aromatic compounds by capillary electrophoresis in order to investigate the separation selectivity that is induced by the G-gel. Several aromatic compounds were separated in a solution containing GMP and potassium ion at different concentrations. The association constants were calculated by correlating the electrophoretic mobilities of the analytes obtained experimentally using a concentration of G-gel. During semi-quantitative estimation, naphthalene derivatives had larger association constants (K-ass = 10.3-16.8) compared with those of benzene derivatives (K-ass = 3.91-5.31), which means that the binding sites of G-gel match better to a naphthalene ring than to a benzene ring. A hydrophobic interaction was also found when the association constants for alkyl resorcinol were compared with those of different hydrocarbon chains. The association constants of nucleobases and tryptophan ranged from 6.05 to 12.6, which approximated the intermediate values between benzene and naphthalene derivatives. Consequently, the selective interaction between G-gel and aromatic compounds was classified as one of three types: (1) an intercalation into stacked planar GMP tetramers; (2) a hydrophobic interaction with a long alkyl chain; or, (3) a small contribution of steric hindrance and/or hydrogen bonding with functional groups such as amino and hydroxyl groups.
en-copyright=
kn-copyright=

en-aut-name=YamaguchiKaori
en-aut-sei=Yamaguchi
en-aut-mei=Kaori
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=1
ORCID=

en-aut-name=TakeyasuNobuyuki
en-aut-sei=Takeyasu
en-aut-mei=Nobuyuki
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=2
ORCID=

en-aut-name=KanetaTakashi
en-aut-sei=Kaneta
en-aut-mei=Takashi
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=3
ORCID=

affil-num=1
en-affil=
kn-affil=Okayama Univ, Grad Sch Nat Sci & Technol, Div Earth Life & Mol Sci, Dept Chem

affil-num=2
en-affil=
kn-affil=Okayama Univ, Grad Sch Nat Sci & Technol, Div Earth Life & Mol Sci, Dept Chem

affil-num=3
en-affil=
kn-affil=Okayama Univ, Grad Sch Nat Sci & Technol, Div Earth Life & Mol Sci, Dept Chem
en-keyword=Capillary electrophoresis
kn-keyword=Capillary electrophoresis
en-keyword=5 '-Guanosine monophosphate (GMP)
kn-keyword=5 '-Guanosine monophosphate (GMP)
en-keyword=G-gel
kn-keyword=G-gel
en-keyword=Association constant
kn-keyword=Association constant
END