Iron, Iron Research Articles

Simple, Hackable, Size-Selective, Amine-Functionalized Fe-Oxide Nanoparticles for Biomedical Applications.

A facile one-pot method for synthesizing amine-functionalized nonspherical Fe3O4 nanoparticles in gram-scale quantities is presented using just a single source of iron (iron(II) chloride) and an amine (triethylamine). The amine not only transforms iron salt to Fe3O4, but also directs the morphology of the nanoparticles along with the temperature of the reaction and functionalizes them, making the synthesis very economical. By modifying the surface further, these nanoparticles promise to offer useful biomedical applications. For example, after biocide coating, the particles are found to be 100% effective in deactivating methicillin-resistant Staphylococcus aureus (MRSA) bacteria in 2 h. Cellular-uptake studies using biocompatible EDTA-Na3 (N-(trimethoxysilyl-propyl)ethylenediaminetriacetate, trisodium salt)-coated nanoparticles in human glioblastoma U-251 cells show that the majority of the particles are internalized by the cells in the presence of a small dc-magnetic field, making these particles a potential candidate as drug carriers for magnetic field-targeted delivery and hyperthermia.

산세수와 게껍질을 이용한 신기능성 철분 비료의 상추 생육 촉진 효과

작물 재배에서 빈번히 발생되는 철분 부족 현상은 식물의 생육 저하와 생산성 감소를 야기한다. 철분의 흡수는 철분 킬레이트제를 이용해서 높일 수 있다. 본 연구에서는 제철산업의 부산물인 산세수 유래의 2가 철 이온을 게껍질(CSP)에 킬레이트시킨 신기능성 철분 비료(FCSP)를 제작하고, 상추 재배에 적용하여 생육 촉진 효과를 분석하였다. 제조한 철 비료의 효과를 검증하기 위해, 연구실 내 소규모 시험에서 무처리구, 게껍질 처리구, 그리고 여러 농도의 Fe-게껍질 킬레이트 처리구에서 상추의 생장을 분석한 결과, 50 ppm Fe-게껍질 킬레이트 처리구에서 엽수, 엽중, 엽장 및 엽폭이 무처리구와 게껍질 처리구에 비해 증가하였으며, 상추 잎의 엽록소의 함량 또한 증가하였다. 포장 시험 역시 50 ppm Fe-게껍질 킬레이트 처리구에서 엽수, 엽중, 엽장 및 엽폭에서 화학비료와 퇴비를 혼합한 기존 재배 방식 처리구에 비해 최대 2배 이상의 증가를 보였고, 식물체내 Fe의 함량 또한 가장 높게 나타났다. 또한 철 이온을 게껍질에 킬레이트한 비료의 처리가 토양 내의 Fe와 Ca의 함량을 증가시켰으며 유효인산과 유기물의 함량 또한 증가시켜 토질을 개선시키는 효과를 보였다. 이러한 결과들을 종합할 때, Fe-게껍질 킬레이트 복합체는 기존의 비료 처리 방식인 화학비료와 퇴비 사용 보다 뛰어난 생육 증대 효과와 토질 개선 효과를 나타냄으로써 작물 재배에 있어서 효과적인 신기능성 철분 소재로서 활용 가치가 있을 것으로 사료된다. Iron (Fe) is an important micronutrient for the health and growth of plants. Iron is usually provided by fertilizers, and iron-chelate fertilizers are well absorbed by plants. This study presents the plant growth-promoting effects of a new functional iron fertilizer, Fe-chelating crab shell powder (FCSP), which is generated from the chelation of Fe ions with crab shell powder. Iron chelate was derived from spent pickling liquor, which is rich in reductive iron, iron(II) oxide. To analyze the effects of FCSP on plant growth, we treated lettuce with several concentrations of FCSP in both lab- and field-scale experiments. In the lab-scale test, the treatment of 50 ppm of FCSP highly promoted growth and resulted in increases in the size, weight, number and chlorophylls content of leaves of plants compared to the treatment of crab shell powder. Fifty ppm of FCSP also increased the size and weight of leaves up to 2 times compared to the application of chemical fertilizer and/or compost in field conditions. In addition, the FCSP treatment resulted in the highest ion uptake of Fe in lettuce leaves. Moreover, FCSP led to increases in the amounts of Fe, Ca, available phosphorus and organic matter in treated soil, indicating that soil quality was improved. Taken together, our results demonstrate that FCSP promotes lettuce growth via enhancement of Fe availability and improves soil quality. Therefore, FCSP can be utilized as a new functional iron fertilizer.

7 - Effect of Iron on Mitochondrial Function and RNA Oxidation

Objectives Iron is a redox reactive metal and causes reactive oxygen species formation via the Fenton reaction; Iron(II) is oxidized by hydrogen peroxide (H2O2) to iron(III), thereby forming the reactive hydroxyl radical. Subsequently, the hydroxyl radical can cause oxidative damage to cellular macromolecules. The mitochondria contribute to H2O2 formation and also take part in iron metabolism. We wanted to investigate if iron has an effect on mitochondrial function. Furthermore, we wanted to examine if iron increased RNA oxidation. Methods Experiments were performed on permeabilized mice muscle fibers. Mitochondrial function was measured by the Oxygraph-2k (Oroboros Instruments) as respiration and H2O2 production. Iron (iron(II)sulfate, 0.1mM or 1 mM) was added during OXPHOS state (maximal respiration). Effect of iron chelator DFOM (0.1mM) was tested. In separate experiments permeabilized fibers were incubated for an hour with iron (0.01mM, 0.1mM and 1mM) and RNA oxidation was measured as 8-oxo-7,8-dihydroguanosine (8-oxoGuo) per 106 guanosine by UPLC-MS/MS. Results Addition of iron did not change the mitochondrial respiration (p=0.9). Addition of DFOM did not have an effect on respiration when comparing post-iron and post-DFOM addition (p=0.4). H2O2 production increased only when 1mM iron was added (p=0.05), however this was also observed in experiments without a biopsy. DFOM decreased H2O2 production in experiments with the biopsies, but had surprisingly no effect when no biopsy was present. We saw a significant 8-oxoGuo increase when adding iron, the increase being higher, the higher the iron concentration (p Conclusions Iron does not have an acute effect on mitochondrial OXPHOS state or H2O2 production in mice biopsies. The observed increase in H2O2 production is suspected to be caused by a chemical reaction between iron and the used buffer. However, addition of iron causes RNA oxidation. The acute effect of iron on RNA oxidation does not seem to be mediated by mitochondrial damage.

Green Method to Form Iron Oxide Nanorods in Orange Peels for Chromium(VI) Reduction

A green method for synthesizing iron oxide nanorods within orange peel pith has been developed. Orange peel pith functions as both a support and a reducing agent for iron ions. The nanorods were characterized using scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. Results of the characterization indicate that iron is deposited on the surface of orange peel primarily in the form of iron, iron(II) oxide and magnetite. The nanoparticles grow to form nanorods in the range of 20-40 nm of diameter. The biocomposite was then tested for Cr(VI) reduction and removal from aqueous solutions, exhibiting removals as high as 96% for concentrations of 10 mg/L and 76% for 50 mg/L, which is almost 4 times the removal capacity of orange peel alone.

Improved Spectrophotometric Determination of Total Iron and Iron(III) with <i>o</i>-Hydroxyhydroquinonephthalein and Their Characterization

Simultaneous and fractional determination of iron(II) and iron(III) was accomplished with o-hydroxyhydroquinonephthalein (QP) in the presence of poly (N-vinyl pyrrolidone). In the determination of total iron (iron(II)+iron(III)), Beer's law was obeyed in the range of 0.02-0.67 μg·ml(-1), with an effective molar absorptivity (at 570 nm) and a relative standard deviation of 1.30×10(5)·l·mol(-1)·cm(-1) and 0.77% (n = 8), respectively. This method was about 10-15 times and more than the methods using 1,10-phenanthroline and 2,2'-bipyridine. In addition, the iron-QP complex was characterized using spectrophotometry and the electron spin resonance. This method was successfully applied to assays of total iron and iron(III) in pharmaceutical preparations.

Polarographic determination of total iron, iron(II) and iron(III) in zinc plant electrolyte

Polarographic methods for the determination of iron(II), iron(III) and total iron in zinc plant electrolyte have been investigated. To provide a suitable medium for the determination, an aliquot of zinc plant electrolyte is added to a 0.1 M citrate-0.1 M EDTA solution and adjusted to pH 6.0 with ammonia. Polarograms recorded under these conditions provide a reversible Fe(III) + e − ⇄Fe(II) response which is essentially independent of whether iron(II) or iron(III) standard solutions are used for calibration purposes. The media used eliminates interference from copper and precipitation of insoluble materials which occurs with more commonly used electrolytes for the polarographic determination of iron. Measurement of the differential pulse and current sampled dc polarograms followed by sequential addition of iron(II) and iron(III) iron standards provides an efficient method for the simultaneous determination of total iron, iron(II) and iron(III) in the 30–100 mg 1 −1 range. However, while the results for the total iron method can be validated, it has not been possible to establish whether or not transport of plant electrolyte circulating at elevated temperatures to a polarographic cell maintained at ambient temperature modifies the ratio of the two oxidation states.

Redox conditions and alkalinity generation in a seasonally anoxic lake (Lake Greifen)

The redox conditions occurring in Lake Greifen during summer stagnation are examined on the basis of the redox species nitrate and ammonium, manganese (manganese (II) and manganese (III, IV) oxides) and iron (iron(II) and iron(III) oxides). The appearance of the reduced species over the course of the stagnation period corresponds qualitatively to the thermodynamic redox sequence, although no equilibrium is established between the various redox species and thus no single pe value can be defined. Occurrence of manganese (II) and the reduction of nitrate are predominant, while iron (II) and sulphide occur only at the last stage of stagnation. The concentration of manganese (II) near the sediment—water interface is limited by the solubility of MnCO 3 (s). The increase of alkalinity in the anoxic hypolimnion over stagnation time is related to the reduction of nitrate.

Selective Increase of Iron in Substantia Nigra Zona Compacta of Parkinsonian Brains

Histochemical and biochemical determinations of total iron, iron (II), and iron (III) contents in brain regions from Parkinson's and Alzheimer's diseases have demonstrated a selective increase of total iron content in parkinsonian substantia nigra zona compacta but not in the zona reticulata. The increase of iron content is mainly in iron (III). The ratio of iron (II):iron (III) in zona compacta changes from almost 2:1 to 1:2. This change is thought to be relevant and may contribute to the selective elevation of basal lipid peroxidation in substantia nigra reported previously. Iron may be available in a free state and thus can participate in autooxidation of dopamine with the resultant generation of H2O2 and oxygen free radicals.

Simultaneous Spectrophotometric Determination of Iron(II) and Iron(III) in Mixtures Using Di-2-pyridyl Ketone Benzoylhydrazone

Abstract A method for simultaneous spectrophotometric determination of total iron, iron(II) and iron(III) in mixtures containing other metal ions has been described. The method is based on the complexation of iron with di-2-pyridyl ketone benzoylhydrazone (DPKBH) in 50% (v/v) ethanolic solution. Iron(II) complex with DPKBH exhibits two absorption maxima at 360 and 650 nm. meanwhile iron(II1) complex with DPKBH exhibits only one maximum at 360nm. Iron(II) and iron(III) complexes with DPKBH have similar behaviour at 360nm. Iron forms 1:2 complexes with the reagent. Beer's laws are obeyed over the ranges 0.1–2 μgml-1 and 0.4–5 μgrn1-l for iron(II) complexes at 360 and 650nm respectively. Iron(III) showed results similar to those obtained for iron(II) at 360nm. The effect of pH, effect of excess reagent. the stability of complexes. and the tolerance limit of many metal ions have been reported. The method is applied to the determination of total iron, iron(I1). and iron(II1) in synthetic solutions.

Determination of iron(II) in rock, soil and clay

A rapid and direct method for the determination of iron(II) in silicates is described. Redox processes frequently occurring during decomposition are suppressed satisfactorily by limiting the reaction time to 10 s while maintaining the temperature at 60–65 °C. Reproducible decomposition temperatures are achieved by mixing concentrated sulphuric and hydrofluoric acids (1 + 3 V/V) in the reaction vessel. The coloured iron(II)-1, 10-phenanthroline complex is used in the spectrophotometric determination of the two valency states of iron, iron(II) directly and iron(III) by difference after subsequent reduction by hydroquinone. Mean results of duplicates of the USGS geological standards G-2, AGV-1 and BCR-1 are within 0.1% and those for DTS-1 and PCC-1 within 0.3% of the quoted average values for iron(II) oxide.

Aromatic acylations catalysed by metal oxides

Dimethylbenzophenones are obtained in high yield from reactions between benzoyl chloride and each of the three isomeric xylenes during 10 h at 150 °C in the presence of small amounts of iron(III) oxide, zinc oxide, ammonium molybdile:tin(II) oxide, molybdenum(VI) oxide, or sodium tungstate. Oxides of titanium, aluminium, chromium, manganese, vanadium, thorium, copper, zirconium, tungsten, and ammonium vanadate are ineffective under these conditions. The benzoylation of 1,4-xylene also occurs in the presence of iron, iron(II) sulphate, iron(III) sulphate, and iron(III) chloride. Iron(III) oxide catalyses the benzoylation of anisole, alkylbenzenes, and halogenobenzenes to give the appropriate 4-substituted benzophenones in high yield. 1,3-Xylene undergoes acylation and sulphcnylation with reagents such as chloroacetyl chloride and benzenesulphonyl chloride, respectively, in the presence of ammonium molybdate to give the appropriate acetophenone or aromatic sulphone. The relative rates of the reaction between benzoyl chloride and 1,4-xylene in the presence of most of the catalysts mentioned have been assessed by estimating the amount of hydrogen chloride evolved.

The analysis of slag for copper, total iron, iron(II) and iron(III) by titration, controlled potential coulometry and electrodeposition

The interference of copper in the titrimetric determination of iron(II), iron-(III) and total iron in slags is discussed. The titration of iron(II) suggested by Bowen and Schairer is accurate and can be conducted with a reproducibility of ±0.29% at the 95% confidence level. Electrolytic copper-iron separation techniques were adapted to copper-containing iron-silicate slag, to obtain a reliable method for copper and total iron analysis. The theoretical and practical limitations for performing potentiostatic determinations of iron(III) in copper-containing slag are reviewed. Some determinatons were made but initial results were unreliable. Complete analyses of copper-gold alloys were made potentiostatically. Copper plus gold recoveries were ca. 99.8%.

Determination of metallic iron, iron(II) oxide, and iron(III) oxide in a mixture

A procedure is described for the estimation of metallic iron, ferrous oxide, and ferric oxide when present together. The sample is treated with bromine dissolved in ethanol, and filtered. Iron in the filtrate is titrated iodometrically, and corresponds to the metallic iron present in the mixture. The oxide residue is dissolved in hydrochloric acid under a carbon dioxide atmosphere. The iron(II) formed, equivalent to FeO present, is titrated with a standard vanadate solution, and the total iron(III) (FeO + Fe 2O 3) in the titrated solution is then estimated iodometrically.