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| 1.
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Begum, Zinnat A. ; Rahman, Ismail M. M. ; Tate, Yousuke ; Egawa, Yuji ; Maki, Teruya ; Hasegawa, Hiroshi
概要:
The protonation and complex formation equilibria of two biodegradable aminopolycarboxylate chelants {dl-2-(2-carboxymeth
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yl)nitrilotriacetic acid (GLDA) and 3-hydroxy-2,2′-iminodisuccinic acid (HIDS)} with Ni 2+, Cu 2+, Zn 2+, Cd 2+ and Pb 2+ ions were investigated using the potentiometric method at a constant ionic strength of I = 0.10 mol·dm -3 (KCl) in aqueous solutions at 25 ± 0.1 °C. The stability constants of the proton-chelant and metal-chelant species for each metal ion were determined, and the concentration distributions of various complex species in solution were evaluated for each ion. The stability constants (log 10K ML) of the complexes containing Ni 2+, Cu 2+, Zn 2+, Cd 2+ and Pb 2+ ions followed the identical order of log 10K CuL > log 10K NiL > log 10K PbL > log 10K ZnL > log 10K CdL for either GLDA (13.03 > 12.74 > 11.60 > 11.52 > 10.31) or HIDS (12.63 > 11.30 > 10.21 > 9.76 > 7.58). In each case, the constants obtained for metal-GLDA complexes were larger than the corresponding constants for metal-HIDS complexes. The conditional stability constants (log 10 {Mathematical expression}) of the metal-chelant complexes containing GLDA and HIDS were calculated in terms of pH, and compared with the stability constants for EDTA and other biodegradable chelants. © 2012 Springer Science+Business Media New York.
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| 2.
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Begum, Zinnat A. ; Rahman, Ismail M. M. ; Tate, Yousuke ; Egawa, Yuji ; Maki, Teruya ; Hasegawa, Hiroshi
概要:
The protonation and complex formation equilibria of two biodegradable aminopolycarboxylate chelants {dl-2-(2-carboxymeth
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yl)nitrilotriacetic acid (GLDA) and 3-hydroxy-2,2′-iminodisuccinic acid (HIDS)} with Ni 2+, Cu2+, Zn2+, Cd2+ and Pb 2+ ions were investigated using the potentiometric method at a constant ionic strength of I = 0.10 mol·dm-3 (KCl) in aqueous solutions at 25 ± 0.1 C. The stability constants of the proton-chelant and metal-chelant species for each metal ion were determined, and the concentration distributions of various complex species in solution were evaluated for each ion. The stability constants (log10 K ML) of the complexes containing Ni2+, Cu2+, Zn2+, Cd2+ and Pb2+ ions followed the identical order of log10 K CuL > log10 K NiL > log10 K PbL > log10 K ZnL > log10 K CdL for either GLDA (13.03 > 12.74 > 11.60 > 11.52 > 10.31) or HIDS (12.63 > 11.30 > 10.21 > 9.76 > 7.58). In each case, the constants obtained for metal-GLDA complexes were larger than the corresponding constants for metal-HIDS complexes. The conditional stability constants (log10 $$ K-{\text{ML}}^{'} $$) of the metal-chelant complexes containing GLDA and HIDS were calculated in terms of pH, and compared with the stability constants for EDTA and other biodegradable chelants. © 2012 Springer Science+Business Media New York.
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| 3.
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Begum, Zinnat A. ; Rahman, Ismail M. M. ; Sawai, Hikaru ; Tate, Yousuke ; Maki, Teruya ; Hasegawa, Hiroshi
概要:
The complex formation equilibria of Cr3+ and Fe3+ ions in aqueous solution with two biodegradable aminopolycarboxylate c
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helants (dl-2-(2-carboxymethyl)nitrilotriacetic acid (GLDA) and 3-hydroxy-2,2'- iminodisuccinic acid (HIDS)) were investigated. The potentiometric data obtained at the constant ionic strengths (I) of (0.1 and 1.0) mol·dm-3 KCl and at (25 ± 0.1) °C was processed with the aid of the computer program HYPERQUAD 2008. The formation constants of the proton-chelant and metal-chelant (log KML) species (M = Fe3+ or Cr 3+; L = GLDA or HIDS) were determined, and the concentration distributions of complex species in solution were evaluated for both metal ions. In various pH conditions, the interaction between the chelants (L = GLDA or HIDS) and the metal ions (M = Fe3+ or Cr3+) leads to the formation of different complexes formulated as MH2L+, MHL, ML-, M(OH)L2-, and M(OH)2L3-. The log KML values at I = 0.1 mol·dm-3 KCl (T = (25 ± 0.1) °C) were 15.27 (log KFe-GLDA), 14.96 (log K Fe-HIDS), 13.77 (log KCr-GLDA), 12.67 (log K Cr-HIDS), and at I = 1.0 mol·dm-3 KCl (T = (25 ± 0.1) °C) were 14.79 (log KFe-GLDA), 14.34 (log K Fe-HIDS), 12.90 (log KCr-GLDA), 12.09 (log K Cr-HIDS). The conditional stability constants (log K'ML) of the ML complexes were calculated in terms of pH in the range of 2 to 12 and compared with the same for EDTA and other biodegradable chelants (NTA and EDDS). © 2012 American Chemical Society.
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| 4.
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Rahman, Ismail M. M. ; Furusho, Yoshiaki ; Begum, Zinnat A. ; Sato, Rika ; Okumura, Hiroshi ; Honda, Hiroko ; Hasegawa, Hiroshi
概要:
Lead (+2) was selectively adsorbed on a solid phase extraction (SPE) gel (molecular recognition technology, MRT), quanti
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tatively extracted, and spectrophotometrically determined as the Pb(II)-PAR (4-(2-pyridylazo)- resorcinol) complex. The linear range was 0.01 to 0.75 mg L-1 and the detection limit was 6.4 μg L-1. The MRT-SPE allows selective Pb(II) extraction from complex ion-rich matrices, which is difficult with other techniques. Interference from common matrix ions such as Fe2+, Ni2+, Cu2+ or Co2+ is minimized. [Figure not available: see fulltext.] © 2013 Versita Warsaw and Springer-Verlag Wien.
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| 5.
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Rahman, M. Azizur ; Hasegawa, Hiroshi ; Rahman, M. Mamunur ; Maki, Teruya ; Lim, Richard P.
概要:
Being predominant inorganic arsenicals, methylarsenicals also occur in anaerobic paddy soils. Therefore, this study inve
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stigated the influence of Fe2+ concentrations and arsenic speciation [arsenate (As(V)) and dimethylarsinate (DMA)] in paddy soils on arsenic uptake in rice plant. Rice seedlings were grown in soil irrigated with a Murashige and Skoog (MS) growth solution containing As(V) or DMA with or without 1.8 mM Fe2+ in excess to the background concentration of total iron (0.03 mM) in the soil. Arsenic concentration in rice roots increased initially and then decreased gradually when the seedlings were grown with excess Fe2+ and As(V). In contrast, arsenic concentration in the roots increased steadily (P < 0.01) when the seedlings were grown without excess Fe2+ and As(V). When the form of the arsenic was DMA, total arsenic (tAs) concentration in rice roots increased gradually (P < 0.01) and was not affected by the addition of excess Fe2+ in the soil. When rice seedlings were grown with As(V), tAs concentration in rice roots and shoots increased steadily (P < 0.01) for gradual increase of Fe2+ concentrations in soil. However, tAs concentration in roots and shoots was independent of Fe2+ concentrations in soil when the form of arsenic was DMA. The tAs concentrations in rice shoots also increased significantly (P < 0.01) with increasing exposure time for both As(V) and DMA. Thus, Fe2+ concentrations in soil affect arsenic uptake in rice plant depending on the speciation of arsenic. © 2013 Springer Science+Business Media Dordrecht.
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| 6.
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Habibullah, M. ; Rahman, Ismail M. M. ; Uddin, M. Ashraf ; Iwakabe, Koichi ; Azam, Anisul ; Hasegawa, Hiroshi
概要:
Densities and viscosities of the binary systems of phenylmethanol with 2-butanone were measured for the entire compositi
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on range at T = (303.15, 308.15, 313.15, 318.15, and 323.15) K and at the atmospheric pressure. The excess molar volumes were derived from the experimental data and were fitted with the Redlich-Kister equation to obtain their coefficients and standard deviations. The Grunberg-Nissan equation was used to correlate the viscosity data. Furthermore, kinematic viscosities were compared with those predicted by the UNIFAC-VISCO model. The cause of relatively large deviations between the experimental and predicted kinematic viscosities was explored by comparing the combinatorial and residual terms of the UNIFAC-VISCO model. © 2011 American Chemical Society.
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| 7.
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Hasegawa, Hiroshi ; Nakagawa, K. ; Rahman, Mohammad Azizur ; Takemura M. ; Maki, Teruya ; Naito, K. ; Rahman, Mahmuda Mamunur
概要:
A new fluorescent-based high-performance liquid chromatography (HPLC) assay using 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-C1) was employed to determine iron (Fe) bioavailability to red tide phytoplankton in seawater. After growing
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four red tide species (Prymnesium parvum, Heterosigma akashiwo, Eutreptiella gymnastica, and Oltmannsiellopsis viridis) in f/2 artificial seawater under different Fe conditions, soluble extracts of the phytoplankton were derivatized using different fluorescent reagents (NBD-C1, 4-fluoro-7-nitrobenzo-2-oxa-1,3-diazole; NBD-F, fluorescamine, and ortho-phthalaldehyde; OPA) followed by HPLC assay. Among the four fluorescent reagents, NBD-C1 was most effective for derivatizing the phytoplankton extracts which would consist of proteins and peptides. HPLC chromatograms of the NBD-derivatized extracts showed gradual changes (decrease/increase) of six peaks for different Fe conditions. Four of the peaks decreased, while two peaks increased with the increase of Fe concentrations in the culture medium. Considering the consistency and sensitivity of chromatogram peaks E and A to different Fe, phosphate and nitrate conditions for all phytoplankton studied, the ratio of these two peaks (IE/A) has been proposed as the indicator of Fe bioavailability to red tide phytoplankton.<br />In Press
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| 8.
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論文
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Hasegawa, Hiroshi ; Nakagawa, K. ; Rahman, Mohammad Azizur ; Takemura, M. ; Maki, Teruya ; Naito, K. ; Rahman, Mahmuda Mamunur
概要:
A new fluorescent-based high-performance liquid chromatography (HPLC) assay using 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-C1) was employed to determine iron (Fe) bioavailability to red tide phytoplankton in seawater. After growing
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four red tide species (Prymnesium parvum, Heterosigma akashiwo, Eutreptiella gymnastica, and Oltmannsiellopsis viridis) in f/2 artificial seawater under different Fe conditions, soluble extracts of the phytoplankton were derivatized using different fluorescent reagents (NBD-C1, 4-fluoro-7-nitrobenzo-2-oxa-1,3-diazole; NBD-F, fluorescamine, and ortho-phthalaldehyde; OPA) followed by HPLC assay. Among the four fluorescent reagents, NBD-C1 was most effective for derivatizing the phytoplankton extracts which would consist of proteins and peptides. HPLC chromatograms of the NBD-derivatized extracts showed gradual changes (decrease/increase) of six peaks for different Fe conditions. Four of the peaks decreased, while two peaks increased with the increase of Fe concentrations in the culture medium. Considering the consistency and sensitivity of chromatogram peaks E and A to different Fe, phosphate and nitrate conditions for all phytoplankton studied, the ratio of these two peaks (IE/A) has been proposed as the indicator of Fe bioavailability to red tide phytoplankton.
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| 9.
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論文
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Rahman, Ismail M. M. ; Uddin, M. Ashraf ; Iwakabe Koichi ; Adhikhari, Anath B. ; Majid, M. Abdul ; Hasegawa, Hiroshi
概要:
金沢大学理工研究域物質化学系<br />Viscosities of binary liquid mixtures of butan-2-one with benzene were measured at a number of mole
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fractions at T = (303.15, 313.15, and 323.15) K and atmospheric pressure. The viscometric behavior is discussed on the basis of structural and geometrical effects between the components. In addition, kinematic viscosities were calculated using the UNIFAC-VISCO model. The predicted kinematic viscosities are in good agreement with the experimental ones. © 2011 American Chemical Society.
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| 10.
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Begun, Zinnat A. ; Rahman, Ismail M.M. ; Hasegawa, Hiroshi ; 長谷川, 浩
概要:
金沢大学理工研究域物質化学系<br />The complexation of SrII and geochemically-related elements (MgII, CaII, BaII, and YIII) with biodeg
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radable aminopolycarboxylate chelators (DL-2-(2-carboxymethyl)nitrilotriacetic acid (GLDA) and 3-hydroxy-2,2′-iminodisuccinic acid (HIDS)) was evaluated with the objective of using in the chemical-induced washing remediation of radioactive solid waste. The stability constants (log10KML) for metal-chelator (ML) complexes between M (MgII, CaII, SrII, BaII, or YIII) and L (GLDA or HIDS) in the aqueous matrix was derived from experimental potentiometric data (M:L = 1:1; ionic strength, I = 0.10 mol·dm− 3; T = 25 ± 0.1 °C). The formation of ML2 − species was dominant in the systems with MgII, CaII, SrII, or BaII, while M(OH)L2 − or M(OH)2L3 − was the major species with YIII. The stability of YIII-L complexes was higher than that of MgII, CaII, SrII, or BaII, while the order for complexation strength of GLDA and HIDS was not similar with divalent ions: M-GLDA (log10KMg-L < log10KCa-L > log10KSr-L > log10KBa-L), M-HIDS (log10KMg-L > log10KCa-L > log10KSr-L > log10KBa-L). The conditional stability constants for the ML systems was also derived in terms of pH (2 to 12), and compared with that of EDTA and EDDS. The data trend indicated that the overall stability of the complexes of MgII, CaII, SrII, BaII, or YIII with GLDA or HIDS was better than the biodegradable chelator EDDS, which was frequently recommended as the alternative to EDTA. © 2017 Elsevier B.V.<br />Embargo Period 12 months
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