Capillary electrophoresis study of iron(II) and iron(III) polyaminocarboxylate complex speciation

2011 ◽  
Vol 8 (3) ◽  
pp. 295 ◽  
Author(s):  
Jessica M. Wilson ◽  
Richard F. Carbonaro
Keyword(s):  
Capillary Electrophoresis ◽  
Chelating Agents ◽  
Aqueous Media ◽  
Background Electrolyte ◽  
Chelating Agent ◽  
Iron Cycling ◽  
Iron Species ◽  
New Methods ◽  
Peak Broadening ◽  
Oxidation By Molecular Oxygen

Environmental contextMethods for determining iron species are integral to investigations of iron cycling processes in the environment. Capillary electrophoresis is an effective tool for determining the concentrations of various iron species in solution, but the separations are highly dependent on the electrolyte composition. This study reports the use of capillary electrophoresis to separate and quantify distinct FeII and FeIII complexes with polyaminocarboxylates. AbstractThe purpose of this study was to use capillary electrophoresis to (i) separate and quantify distinct FeII and FeIII complexes with polyaminocarboxylates and (ii) develop new methods for distinguishing between FeII and FeIII in aqueous media. A 25 mM phosphate and a 50 mM 3-(N-morpholino)propanesulfonic acid (MOPS) background electrolyte (BGE), both buffered at pH 7.1, were each tested with 6 polyaminocarboxylate complexes with FeII and FeIII. Adequate separation of all FeIII-chelating agent complexes was observed with the MOPS BGE. With the phosphate BGE, sharp peaks were obtained for FeIII complexes with EDTA, HEDTA, DTPA and CDTA, however FeIII–EGTA showed excessive peak broadening, and FeIII–TMDTA showed no discernable peak. Mobilities of FeIII–EGTA, FeIII–EDTA and FeIII–HEDTA were much larger when the phosphate BGE was employed, providing evidence for ternary complex formation with phosphate during electromigration. For FeII, complexes with TMDTA and EGTA were adequately separated with either BGE, but separations of the other chelating agents resulted in their corresponding FeIII complexes due to rapid oxidation by molecular oxygen. These chelating agents may be used as preservatives and derivatising agents for the analysis of ferrous and ferric iron in environmental samples.

scholarly journals Study on the Behavior and Removal of Cadmium and Zinc Using Taraxacum officinale and Gazania under the Application of Biodegradable Chelating Agents

2021 ◽  
Vol 11 (4) ◽  
pp. 1557
Author(s):  
Naoki Kano ◽  
Takumi Hori ◽  
Haixin Zhang ◽  
Naoto Miyamoto ◽  
David Eva Vanessa Anak ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Chelating Agents ◽  
Environmental Control ◽  
Chelating Agent ◽  
Taraxacum Officinale ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Experimental Treatments ◽  
The One

The removal of cadmium (Cd) and zinc (Zn) from soil by phytoremediation was investigated using Taraxacum officinale and Gazania. A plant environmental control system was used to cultivate the plants. The effects of different biodegradable chelating agents (i.e., EDDS, HIDS, and GLDA), relative humidity, and other competitive metals on the adsorption of Cd and Zn were also studied. In addition, the approach for metal recovery was explored by extraction of metals from plants after phytoremediation using Gazania. The concentrations of Cd and Zn were determined by inductively coupled plasma mass spectrometry (ICP-MS). In addition, one-way analysis of variance (ANOVA) tests were performed.to determine significant differences between the experimental treatments adopted in this work. Consequently, the following main conclusions were obtained: (1) In the case of Taraxacum officinale, Cd and Zn could be removed even under the presence of other heavy metals. (2) By adding a chelating agent, the amount absorbed by the shoot generally increased. (3) In the case of Gazania, the concentration of Cd was higher in root than that in shoot, whereas the concentration of Zn was higher in the shoot than that in the root. (4) Taraxacum officinale was more suitable for phytoremediation of Cd than Gazania. (5) Cd and Zn could be extracted from plants by adding a low concentration of nitric acid. (6) The one-way ANOVA tests showed no statistically significant differences among the experimental treatments.

scholarly journals Chelating agent and substrate effect on hydrothermal growth of Yb3+/Er3+ doped NaYf4 film

2021 ◽  
Vol 15 (1) ◽  
pp. 69-78
Author(s):  
Suman Duhan ◽  
Kedar Sahoo ◽  
Ahmad Imteyaz ◽  
Sudhir Singh ◽  
Manoj Kumar
Keyword(s):  
Crystal Growth ◽  
Hydrothermal Method ◽  
Luminescence Intensity ◽  
Chelating Agents ◽  
Chelating Agent ◽  
Upconversion Emission ◽  
Substrate Effect ◽  
Current Investigation ◽  
One Step ◽  
Film Roughness

We report simultaneous crystal growth and deposition of upconverting Yb3+/Er3+ doped NaYF4 film (UCF) on conducting and non-conducting substrates by one-step hydrothermal method. The characteristics such as film topography, morphology, crystallographic phase and upconverting luminescence intensity were found to depend both on the chelating agent and nature of the substrate. The characteristics of the prepared films varied interestingly when either the chelating agent or the substrate was changed. The upconversion emission intensities were found to increase with decreasing film roughness. Further, current investigation demonstrated that the NaYF4 films deposited using EDTA or DTPA chelating agents on ITO substrate and EGTA chelating agent on PG substrate were more uniform and resulted in greater upconverted emission intensities. We envision plausible use of current technology in the development of affordable optical platforms for several optoelectronic applications.

Effect of EDTA and EDDS on Phytoremediation of Pb- and Zn- Contaminated Soil by Brassica Juncea

2012 ◽  
Vol 518-523 ◽  
pp. 5040-5046 ◽  
Author(s):  
Li Di Gao ◽  
Naoki Kano ◽  
Yuichi Sato ◽  
Shuang Zhang ◽  
Hiroshi Imaizumi
Keyword(s):  
Heavy Metals ◽  
Control System ◽  
Plant Growth ◽  
Brassica Juncea ◽  
Contaminated Soil ◽  
Chelating Agents ◽  
Environmental Control ◽  
Chelating Agent ◽  
Whole Plant ◽  
Biomass Loss

Effect of EDTA and EDDS on phytoremediation of Pb- and Zn- contaminated soil by Brassica Juncea was investigated in this work. Especially, the effect of the kind and the method of adding chelating agent was investigated during the plant growth. Plants were grown in an environmental control system. The biomass of the whole plant was weighed, and the uptake of Pb and Zn in shoot and root were determined using ICP-AES. Consequently, the following matters have been obtained: (1) Both EDTA and EDDS significantly enhanced the translocation of metals (Pb and Zn) in soil from root to shoot. Furthermore, the two chelating agents resulted in a sharply biomass loss for more than 30% of the control. As a result, the total uptake amount of metals by Brassica Juncea was decreased (except the uptake of Pb with the addition of 3.0 mmol•kg-1 EDTA). (2) EDDS showed the higher inhibition for the growth of Brassica Juncea than EDTA. (3) The method for adding EDTA and EDDS at several times separately did not necessarily increase the uptake of heavy metals.

scholarly journals The Use of Hydrazones for Biomedical Applications

2019 ◽  
Vol 24 (2) ◽  
pp. 161-168 ◽  
Author(s):  
Jenna Wahbeh ◽  
Sarah Milkowski
Keyword(s):  
Drug Release ◽  
Biomedical Applications ◽  
Chelating Agents ◽  
Tumor Tissue ◽  
Review Paper ◽  
Chelating Agent ◽  
Diverse Range ◽  
Site Specific ◽  
Anti Inflammatory ◽  
The Many

The use of hydrazones presents an opportunity for enhancing drug delivery through site-specific drug release, including areas such as tumor tissue or thrombosis. Many researchers are experimenting on how to more efficiently form these hydrazones, specifically using heat and chemical catalysts. Hydrazones respond on the pH environment or are synthesized with particular functional groups of the hydrazone and are two of the many unique features that allow for their programmed drug release. Their flexibility allows them to be relevant in a diverse range of applications, from anti-inflammatory to anticancer to acting as a chelating agent. This review paper discusses efficient ways to optimize the properties of hydrazones and their utilization in various clinical applications, including anticancer, anti-inflammatory, the prevention of platelet aggregation, and roles as chelating agents.

Chelating-Agent Enhanced Oil Recovery for Sandstone and Carbonate Reservoirs

SPE Journal ◽  
2015 ◽  
Vol 20 (03) ◽  
pp. 483-495 ◽  
Author(s):  
M. A. Mahmoud ◽  
K. Z. Abdelgawad
Keyword(s):  
Zeta Potential ◽  
Oil Recovery ◽  
Chelating Agents ◽  
Water Injection ◽  
Chelating Agent ◽  
Carbonate Reservoirs ◽  
Low Salinity ◽  
Low Salinity Water ◽  
Salinity Water ◽  
Core Permeability

Summary Recently low-salinity waterflooding was introduced as an effective enhanced-oil-recovery (EOR) method in sandstone and carbonate reservoirs. The recovery mechanisms that use low-salinity-water injection are still debatable. The suggested possible mechanisms are: wettability alteration, interfacial-tension (IFT) reduction, multi-ion exchange, and rock dissolution. In this paper, we introduce a new chemical EOR method for sandstone and carbonate reservoirs that will give better recovery than the low-salinity-water injection without treating or diluting seawater. In this study, we introduce a new chemical EOR method that uses chelating agents such as ethylenediaminetetraacetic acid (EDTA), hydroxyethylethylenediaminetriacetic acid (HEDTA), and diethylenetriaminepentaacetic acid (DTPA) at high pH values. This is the first time for use of chelating agents as standalone EOR fluids. Coreflood experiments, interfacial and surface tensions, and zeta-potential measurements are performed with DTPA, EDTA, and HEDTA chelating agents. The chelating-agent concentrations used in the study were prepared by diluting the initial concentration of 40 wt% with seawater and injecting it into Berea-sandstone and Indiana-limestone cores of a 6-in. length and a 1.5-in. diameter saturated with crude oil. The coreflooding experiments were performed at 100°C and a 1,000-psi backpressure. Low-salinity-water and seawater injections caused damage to the reservoir because of the calcium sulfate scale deposition during the flooding process. The newly introduced EOR method did not cause calcium sulfate precipitation, and the core permeability was not affected. The core permeability was measured after the flooding process, and the final permeability was higher than the initial permeability in the case of chelating-agent injection. The coreflooding effluent was analyzed for cations with the inductively coupled plasma (ICP) spectroscopy to explain the dissolution-recovery mechanism. The effect of iron minerals on the rock-surface charge was investigated through the measurements of zeta potential for different rocks containing different iron minerals. HEDTA and EDTA chelating agents at 5 wt% concentration prepared in seawater were able to recover more than 20% oil from the initial oil in place from sandstone and carbonate cores. ICP measurements supported the rock-dissolution mechanism because the calcium, magnesium, and iron concentrations in the effluent samples were more than those in the injected fluids. The IFT-reduction mechanism was confirmed by the low IFT values obtained in the case of chelating agents. The type and concentration of chelating agents affected the IFT value. Higher concentrations yielded lower IFT values because of the increase in carboxylic-group concentration. We found that the high-pH chelating agents increased the negative value of zeta potential, which will change the rock toward more water-wet.

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