Ferrous Sulfate Solution Research Articles

Electrochemical study on Surface Oxidation of Natural Pyrite in Ferric Sulfate Solution

Electrochemical study on Surface Oxidation of Natural Pyrite in Ferric Sulfate Solution

Utilization of Iron in the Third Trimester of Pregnancy in Women with and Without Pre-pregnancy Obesity (P24-013-19)

ObjectivesObese women may be at risk for poor iron status in pregnancy due to pro-inflammatory driven overexpression of hepcidin that leads to decreased iron bioavailability. Our objective was to determine the impact of pre-pregnancy (PP) obesity on maternal iron utilization in the third trimester of a singleton pregnancy. MethodsUsing the stable isotope 57Fe prepared as an oral ferrous sulfate solution, we measured iron absorption based on red blood cell incorporation in 50 adult (mean age: 27.6 ± 6.8 years) pregnant women [n = 29 PP non-obese (body mass index (BMI) 18.5–29.9 kg/m2) and n = 21 PP obese (BMI ≥ 30.0 kg/m2] at the 32nd-34th gestational week (mean 32.7 ± 0.7 weeks). We also assessed maternal iron status, hepcidin, inflammation, erythropoietin, dietary iron intake and gestational weight gain. ResultsIron deficiency defined as hemoglobin < 11.0 g/dL was highly prevalent (PP obese 67% vs. PP non-obese 48%, P = 0.19). 57Fe utilization (PP non-obese 11.2% (interquartile range (IQR), 8.3) vs. PP obese 7.7% (IQR 8.9), P = 0.23), hepcidin, hemoglobin, and soluble transferrin receptor was similar between the PP BMI groups. PP obesity was associated with significantly higher ferritin, high sensitivity C-reactive protein, and total body iron. In the women who were non-obese PP, 57Fe utilization was not linearly associated with any of the iron-related or inflammatory indices tested. However, 57Fe utilization was significantly inversely associated with serum ferritin (r = −0.42) and serum hepcidin (r = −0.48) in women with PP obesity. In post-hoc analysis, compared to non-obese women, iron utilization was 23% lower in women with class 2 and 3 PP obesity and 3% lower in women with class 1 PP obesity, respectively. ConclusionsIron utilization from an oral ferrous sulfate solution in the third trimester of pregnancy was similar in women with and without PP obesity. Given the growing prevalence of class 2 and 3 obesity among reproductive age women, and the importance of iron for optimal maternal and fetal health, our post-hoc analysis suggests that future efforts should examine iron utilization in women with severe PP obesity. Funding SourcesRobert Wood Johnson Foundation, Nurse Faculty Scholars Program #72,117 and University of Illinois at Chicago Colleges of Nursing and Medicine.

Duodenal Ferroportin Expression Is Unresponsive to Dietary Iron Excess in Nursing Piglets (FS04-01-19)

ObjectivesIn the US, prophylactic iron supplementation without thorough screening for iron deficiency is commonly practiced in both normal weight and low birth weight infants. In a nursing pig model, we previously found that excess dietary iron results in tissue iron overload, suggesting ineffective regulation of intestinal iron absorption. Herein, we aimed to determine if hepcidin-mediated ferroportin (FPN1) degradation is functionally immature in early life. MethodsTwelve nursing piglets of normal birth weight (2.1 ± 0.4 kg, PD2) were supplemented with either low (AGAL, 1 mg/d·kg body weight) or high iron (AGAH, 15 mg/d·kg BW)) in form of ferrous sulfate solution. Eight low birth weight (1.2 ± 0.4 kg on PD2) piglets were supplemented with high iron (SGAH, 15 mg/d·kg BW) from PD2 to 21. All piglets were raised by suckling their sows. Blood samples were collected weekly for analysis of hemoglobin, hematocrit, and plasma iron. Duodenal mucosa (DM) and hepatic mRNA and protein expression of iron transporters and regulators were analyzed using RT-qPCR and Western blot. Data were analyzed using PROC MIXED of SAS with CONTRAST statement for planned comparison between AGAL and high iron groups. ResultsIn comparison with AGAL, high iron, regardless of birth weight, significantly (P < 0.05) increased hemoglobin, transferrin saturation (74% vs. 49%), and plasma iron, and resulted in iron overload in DM and liver at PD21. Hepatic mRNA expression of HAMP and FTL in DM increased 275- and 3-fold, respectively, in response to high iron, whereas DMT1 in DM and TFRC in both liver and DM decreased by 7.4-, 3.8- and 5.3-fold, respectively. Consistently, protein expression of DMT1 in DM was lower in SGAH than that in AGAL; However, both mRNA and protein expression of FPN1 in DM and liver remained unaffected by iron provision or birth weight. ConclusionsHepcidin-induced ferroportin degradation is hypo-responsive to iron excess in a nursing pig model. Funding SourcesUC Davis, NIFA.

A hybrid leaching process to enhance the dissolution of cupriferous micas in the Chingola refractory ore

The occurrence of copper in the Chingola refractory ore (CRO) is such that it is chemically locked in cupriferous micas of predominantly phlogopite, chlorite and vermiculite within the mica lattice. This renders the copper refractory to conventional atmospheric leaching. A few technically feasible processing methods have been proposed but appear economically unfavourable. This study has proposed a hybrid leaching process consisting of ore agglomeration, acid curing and leaching in fixed bed columns to maximise the leach efficiency under ambient conditions. The experimental procedure involved characterization of the ore, agglomeration tests, acid curing and leaching experiments in fixed bed columns. The objective was to understand the conditions under which copper dissolution can be enhanced by specifically targeting the refractory cupriferous micas. The results showed that agglomeration and acid curing of the CRO material doubled the total copper dissolution from 32% Cu for the unagglomerated and un-cured material to about 60% Cu dissolution for the agglomerated material. Short bed heights yielded marginally higher leach efficiencies and also faster leaching kinetics than tall bed heights. More crucially, the hybrid leaching process successfully dissolved up to 90% of the total cupriferous mica in the ore, which is reported to be difficult to leach under ambient conditions. Towards explanation of the phenomenon, it is postulated that the acid curing step rendered the CuOH bonds chemically weak which enhanced copper dissolution from the mica matrix. This leads to partial acid decomposition of the silicate structure and dissolution of the metal cations, leaving a siliceous residue. However, sulphides, especially chalcopyrite was difficult to leach under the conditions employed, for which the use of acidified ferric sulphate solution or bioleaching is recommended. This is a significant step towards the development of a practical leaching process to treat the CRO material.

Preparation and performance characterization of solid polyferric sulfate(SPFS) water purifier from sintering dust

The mother solution of high purity ferric sulfate can be extracted by water washing, acid leaching, high-temperature aging, water leaching and removing K, Ca and Si elements with high content in sintering dust with sintering dust as raw material. Under the optimal acid leaching scheme, the leaching rate of Fe element can reach 99.8%. Subsequently, the mother solution of high purity ferric sulfate was configured to 100 ml 3 mol L−1 Fe2(SO4)3, and then add 0.1 mol FeSO4.7H2O, mixing reaction 1 h at room temperature, the liquid polyferric sulfate product can be just made. Then the liquid polyferric sulfate can be dried to SPFS product with the 17.4% base degrees at 50 °C. Through the comparison and analysis of TG, DTG and IR test results of purchased SPFS and self-made SPFS, it can be concluded that the self-made SPFS has the similar hydroxyl bridged frame structure with that of purchased SPFS. The experiment of purifying different kinds of simulated dye wastewater with self-made SPFS shows that the optimal pH range of these three dyes is 5–9 in the dye wastewater decolorization experiment and all their chrominance removal rates can reach above 96% at pH = 7.0. In addition, the adsorption isotherm of orange GGL solution is well represented by the Langmuir isotherm model in this experiment.

Preparation of graphene nanosheets by electrochemical exfoliation of a graphite-nanoclay composite electrode: Application for the adsorption of organic dyes

A simple and cost-effective approach to get a few layers of graphene nanosheets is reported in this work. The electrochemical exfoliation of a graphite-nanoclay composite electrode, a pencil core, was carried out in the presence of Mohr's salt (ammonium ferrous sulfate solution) as an electrolyte and aluminum foil as a counter electrode. The unique property behind using this method was that the produced graphene colloid does not require any secondary physical processing or ultra-sonication for separation, as it raised over the electrolyte solution during the exfoliation process. To optimize the exfoliation conditions, different electrolyte concentrations (0.1, 0.5 and 1 M) and D.C bias voltages (7.5, 9 and 12 V) were investigated. The as-produced graphene nanosheets were filtrated, washed and characterized using Raman spectrometer, FT-IR, XRD, SEM and TEM, UV–vis spectrophotometer. The electrochemical exfoliation process was found to produce a few layers of graphene nanosheets with a lateral size ranged from 60 to 210 nm. Based on characterization results, especially Raman and TEM analysis, highly pure graphene nanosheets were obtained at 7.5 V and 0.5 M of electrolyte solution concentration. A promising application of the produced graphene sheets for cationic and anionic dye removal has been investigated. The removal efficiency of the prepared graphene against MO and MB was 22% and 77%, respectively.

Efficacy of Three Toothpastes in Iron Stain Removal from Primary Teeth.

ABSTRACTAimThis study aimed to assess the iron stain removal efficacy of three toothpastes in extracted primary teeth.Materials and methodsIn this in vitro study, 60 extracted sound primary teeth were selected, decoronated at the cementoenamel junction, and their pulp chambers were filled with a composite. The teeth were then immersed in ferrous sulfate solution and brushed 3,000 times in an automatic tooth-brushing machine using Colgate, whitening Crest, and conventional Crest dentifrices. Stain removal was done in four groups using a prophylaxis paste. Digital images were obtained from the teeth before and after brushing with dentifrices and the changes in color parameters were measured using Photoshop and iColor software programs. Changes in color parameters were statistically analyzed using one-way ANOVA while multiple comparisons were done by Tukey's test.ResultsThe greatest change in chroma was observed in the prophylaxis group and then in the whitening Crest, Colgate, and conventional Crest (mean values of −65.2, −31.07, −21.27, and −0.73, respectively). Prophylaxis completely removed the stains. The greatest reduction in value occurred in conventional Crest, Colgate, and whitening Crest (−18.07, −12.23, and −0.4, respectively). In the L*a*b* system, the least reductions were noted in the whitening Crest, Colgate, and conventional Crest (mean values of −1.96, −3.92, and −3.37, respectively). Prophylaxis significantly improved tooth brightness (a mean increase of 4.26).ConclusionNone of the toothpastes in this study were capable of effectively removing iron stains. Crest whitening toothpaste was slightly effective in this regard.Clinical significanceIron drops are routinely prescribed for children younger than 2 years of age to prevent iron deficiency and iron deficiency anemia. However, iron stains on teeth are a common concern for many parents. Finding toothpastes with greater efficacy for iron stain removal can help in this respect.How to cite this articleHeidari A, Shahrabi M, et al. Efficacy of Three Toothpastes in Iron Stain Removal from Primary Teeth. Int J Clin Pediatr Dent 2019;12(1):10–14.

Effectiveness of Iron Therapy on Breath Holding Spells in the Children.

The pathophysiology and mechanism of Breath-Holding Spells (BHS) remain controversial, and the relationship between BHS and anemia has not been clarified, although iron supplementation appears to be effective in many patients. We aimed to assess the probable relation of iron level with initiation of these spells in children. Overall, 42 children with a diagnosis of BHS, aged between 6 months to 2 yr were enrolled during Mar 2015 to Dec 2016 at Rasht 17th Shahrivar Hospital, Rasht, northern Iran. Ferrous sulfate solution prescribed 6 mg/kg/d, 3 times daily, for all of cases, regardless of their iron levels, and the response to the treatment was evaluated. Twenty-five patients were boys (59.52%). The mean age for all patients was 11.71±4.63 months. Positive family history detected in 33.33%; iron deficiency anemia in 21.42%, depletion of iron stores in 52.38%, and normal iron status in 26.19% of cases. Simple spells showed significantly higher mean of Hb in comparison with severe spells (P=0.008); also increased number of spells per month significantly decreased the mean of Hb (P=0.007). Mean frequency of spells was 40.14±47.08 before and 11.14±31.10 after iron therapy, per month (P<0.0001). Overall, 32 patients (76.19%) had complete control of spells, 7 patients (16.66%) partial, 2 cases (4.76%) weak, and 1 child (2.38%) no response after iron therapy. Iron deficiency anemia may have an important role in BHS, and treatment of anemia may decrease number of the spells.

Synchrotron Radiation XRD Investigation of the Fine Phase Transformation during Synthetic Chalcocite Acidic Ferric Sulfate Leaching

The fine phase transformation process of chalcocite (Cu2S) leaching in acidic ferric sulfate solution was studied by leaching experiments and synchrotron radiation X-ray diffraction (SRXRD) tests. The results showed that the dissolution process of chalcocite was divided into two stages. In the first stage, Cu2S was firstly transformed to Cu5FeS4 and Cu2−xS, then the galvanic effect between Cu5FeS4 and Cu2−xS accelerated the dissolution process of Cu1.8S → Cu1.6S → CuS, and finally Cu5FeS4 was also transformed to CuS. While in the second stage, CuS was transformed to elemental sulfur, which formed the passivation layer and inhibited the leaching of chalcocite. Specifically, Cu5FeS4 was detected during the chalcocite leaching process by SRXRD for the first time. This research is helpful for revealing the detailed leaching process of chalcocite.

An Investigation of the Mechanism Magnetite Precipitation Using Ammonium Carbonate

The purpose of this study is to determine the phase composition of iron oxide compounds formed during precipitation by ammonium carbonate hydrolysis products, to establish the magnetite formation regions and the kinetic characteristics of the reaction formation Fe3O4. Characterization by X-ray diffraction (XRD) indicated that magnetite is formed in a solution of ferrous sulphate during the hydrolysis of ammonium carbonate. It has a homogeneous phase composition and a cubic crystal structure. Phase diagrams of the formation of the crystalline phase of magnetite, goethite and ferric hydroxide have been determined. It has been established that magnetite with a spinel structure is formed under controlled slow precipitation from ferrous sulphate with an ammonium carbonate solution. The calculation of the kinetic characteristics of the reactions of solid phase precipitation (a rate constant at different initial concentrations of ferrous sulphate, the order of the reaction) has shown that the process proceeds in two stages with the formation of an intermediate compound and its further oxidation. Moreover, the rate constant of oxidation is 0.654 L/min mol, and the rate constant of the first reaction is much higher – 1.645 L/min mol.

Effects of cathodic electrodeposition conditions on morphology and photoelectrochemical response of α-Fe2O3 photoanode

α-Fe2O3 photoanodes were prepared on Fluorine-doped tin oxide glass by annealing of electrodeposited Fe films. By controlling the synthesis parameters, the α-Fe2O3 film prepared from the Fe film electrodeposited in 0.05 M ferrous sulfate solution (pH = 2.1) for 50 s and then annealed at 600 °C for 3 h has the optimal photocurrent density around 257.08 μA cm−2 at 1.23 V vs. RHE (Reversible Hydrogen Electrode). In this paper, the effects of different synthesis parameters on α-Fe2O3 photoanodes were studied systematically. The morphology and properties of the sample were characterized with scanning electron microscopy, UV–vis spectra, X-ray diffractometry and photoelectrical measurements.

P258] Optical absorbance properties of PVA-GTA Fricke gel dosimeters irradiated with 6 MV and 15 MV X-rays

Purpose Quality assurance procedures required in the modern radiotherapy would greatly benefit by the development of tissue equivalent dosimeters able of rendering 3D dose profiles with high spatial resolution. In this scenario, Fricke gel (FG), consisting in gel matrices infused with Fricke ferrous sulphate solution combined with xylenol orange, could be good candidates, but some limits have prevented their introduction in clinical practice. Recently, new FG formulations based on gel matrices of poly-vinyl alcohol (PVA) cross-linked with glutaraldehyde (GTA) have shown important decrease of the limitations affecting FGs obtained with gelatin or agarose. Purpose of this study is the characterization of the optical absorbance (OA) and dosimetric properties of PVA-GTA FG dosimeters. Methods PVA-GTA FG dosimeters were prepared using 9.1 w/w of Mowiol®-PVA and 26.4 mM of GTA. The dosimeters, placed in spectrophotometry cuvettes (10 mm optical path), were uniformly irradiated using 6 and 15 MV X-rays generated by a Varian Clinac-2100. OA spectra were measured by means of an Agilent Cary-100 spectrophotometer. Dosimetric properties of PVA-GTA-FG dosimeters, such as reproducibility, dose–response, sensitivity, dose-rate dependence and energy dependence, were studied. Furthermore, FG in form of layers (3 mm optical path) were irradiated producing steep dose gradients and used to investigate ferric ions diffusion phenomena by means of sequential light transmittance images. Results The analysis of the OA spectra of the PVA-GTA-FG dosimeters in the wavelength interval of interest for dosimetry purposes (around 550–600 nm) revealed an intra-batch reproducibility of the order of 1.5%. The OA proved to increase linearly with increasing dose, in the investigated interval 0–15 Gy, if the wavelength used for the analysis is properly chosen. The optical response of the PVA-GT-FG dosimeters was independent of both energy and dose-rate. Furthermore, PVA-GTA matrix enables to achieve ferric ions diffusion rates approximatively 3 times lower than those observed in natural gel matrices. Conclusions This study confirmed the interesting properties of PVA-GTA FG dosimeters and indicated the best parameters for their optical analysis. Currently, studies are in progress in order to optimize Magnetic Resonance Imaging procedures for the assessment of 3D dose distributions in PVA-GTA FG phantoms.

Encapsulation of scorodite using crystalline polyferric sulfate precipitated from the Fe(II)-SO42−-O2-H2O system

Scorodite was encapsulated by precipitating a crystalline polyferric sulfate (PFS) coating layer on the surface of scorodite particles to restrain the release of arsenic. The encapsulation experiments were carried out at atmospheric pressure, 90 °C, and 1.5 pH by adding 20 g scorodite particles/L to a 0.1-0.4 mol/L ferrous sulfate solution followed by the introduction of pure oxygen to oxidize and precipitate the ferrous ions as PFS. After encapsulation the samples were characterized using X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and scanning transmission electron microscopy. The results indicated that the coating was crystalline PFS, and the scorodite particles were completely encapsulated by the coating. The stability of the scorodite encapsulated with PFS was evaluated by several toxic leaching tests which use an HAc-NaAc buffer solution of 4.93 pH, a NaOH solution of 9.3 pH, a NaH2PO4-NaOH buffer solution of 8.6 pH, or Na2S solutions of 7.6 and 8.1 pH and a reducing potential (Eh) within the −100 to 0 mV range as leaching solutions. The results of the leaching tests indicated that the scorodite encapsulated with PFS was highly effective at restraining the release of arsenic in both weakly acidic and alkaline solutions under both oxic and anoxic conditions.

Total yield of reactive species originating from an atmospheric pressure plasma jet in real time.

It is now well established that plasma-induced reactive species are key agents involved in many biochemical reactions. This work reports on the formation of plasma reactive species in an acidified ferrous sulfate (Fricke) solution interacting with an atmospheric pressure plasma jet (APPJ). A yield of ferric (Fe3+) ions measured using in situ absorption spectroscopy was attributed to the formation of plasma reactive species provided and/or originated in the solution. The results indicated that the number of reactive species formed was proportional to plasma frequency and voltage. However, the Fe3+ yield per pulse decreased with increased frequency. To obtain a better understanding of the processes and species involved in the chemical reactions due to plasma exposure, Fe3+ yields were calculated and compared to the experimental data. At higher frequencies, there was insufficient time to complete all the reactions before the next pulse reached the solution; at lower frequencies, the Fe3+ yield was higher because of the relatively longer time available for reactions to occur. In addition, the comparison between DNA damage levels and Fe3+ yields was investigated under different experimental conditions in order to verify the usefulness of both the Fricke solution and the DNA molecule as a probe to characterize APPJs.

Recovery of magnetite from waste ferrous sulfate using polyethylene glycol (PEG) as a dispersant

Abstract The effect of PEG dispersant on the magnetic separation of magnetite (Fe3O4) synthesized from ferrous sulfate solution via co-precipitation method with calcium hydroxide as the precipitant was investigated. The results indicated that a PEG dispersant could significantly affect Fe3O4 recovery. Adding PEG during the preparation of Fe3O4 was unfavorable for Fe3O4 recovery. When the PEG-6000 concentration was increased from 0 to 8 g/L, the iron grade and median particle size of the Fe3O4 product decreased from 65.58% and 2.35 μm to 57.79% and 1.35 μm, respectively. However, adding PEG during the wet milling of the mixed product promoted the subsequent recovery of Fe3O4. When the amount of PEG-200 increased from 0% to 4% of the powder mass, the grade of iron in the Fe3O4 product increased from 65.58% to 68.32%. While the relative molecular mass of PEG at an amount of 4% of the powder mass increased from 200 to 20000, the grade of iron was reduced from 68.32% to 66.70%.

Production of low-sulfur hematite by hydrothermal oxydrolysis of ferrous sulfate

Hematite produced by the zinc industry exhibits a high sulfur content, being mainly contaminated by jarosite as the main sulfur-containing phase, and is thus of limited use for the steelmaking industry. Herein, we investigate the effects of parameters such as temperature (170–200 °C) and initial concentrations of sulfuric acid (0–19.6 g/L), sodium sulfate (0–35.5 g/L), hematite seeds (0–30 g/L), and Zn2+ (80–120 g/L) on the formation and conversion of jarosite during hematite precipitation from a ferrous sulfate solution, obtaining high-quality hematite with a low sulfur content.We reveal that increased temperature not only benefits jarosite conversion but also reduces the sulfur content of precipitates and enriches them in iron. Sulfuric acid concentrations of 4.9–19.6 g/L greatly decrease the fraction of precipitated iron and produce sulfur-rich precipitates containing significant amounts of both hematite and jarosite, whereas sodium sulfate increases the iron removal efficiency and the sodium content in hematite precipitates. Hematite seeds prompt the precipitation of hematite and affect the composition of the obtained precipitates, promoting the precipitation of hematite in preference to jarosite at relatively low temperatures. Finally, zinc sulfate concentrations of 80–120 g/L have a positive effect on iron removal as hematite.

Extraction and separation of nonferrous and precious metals from waste of electrical and electronic equipment through ferric sulfate leaching and electrolysis

AbstractBACKGROUNDThe continuous generation of waste electrical and electronic equipment (WEEE) causes serious environmental problems as it is disposed in landfills, because of its hazardous content. In most electronic equipment, there are important components which contain large amounts of nonferrous metals and precious metals.RESULTSSeparation of silver using sieving proved to be efficient; silver was almost entirely collected in the finer fraction (&lt;0.5 mm size). Separating gold from silver and palladium was achieved through leaching the metallic fraction in a 0.5 mol L–1 aqueous ferric sulfate solution at room temperature. A good yield of metal extraction was obtained after leaching using ferrous sulfate. The composition of the cathode deposits points to an almost complete recovery of silver and copper by electrolysis and a partial recovery of tin. Also, cyclic voltammetry tests in the solution (pH adjusted at 0.5) identified cathode peaks at ∼ −0.3 V Ag−1 ref. ascribable to Cu reduction, at ∼ − 0.783 V Ag−1 ref. ascribable to Ni reduction, as well as a plateau in the range −0.75 ↔ −1.0 V Ag−1 ref. ascribable to a simultaneous reduction of several ionic species.CONCLUSIONLeaching from WEEE was carried out by an environmentally friendly procedure using nonpolluting ferric sulfate, and using electrolysis some metals were extracted in good condition. © 2018 Society of Chemical Industry

The ultrasound assisted hydration as an opportunity to incorporate nutrients into grains

Hydration is an important but long step in processing beans. Consequently, any ways of taking advantage of this processing time are desirable. One possibility is to fortify the beans during the hydration process, especially with water-soluble nutrients. This work studied the incorporation of iron into beans during hydration with and without ultrasound, describing the kinetics of water and iron uptake, the entrance pathway and its effect on germination and the cooking process. For that, carioca beans were soaked in ferrous sulfate solution (0.271% w/v) with and without ultrasound (91 W/L; 25 kHz) at 25 °C. It was demonstrated that iron could be incorporated during the hydration process, describing a similar kinetics behavior to the water uptake. In addition, ultrasound accelerated this process, achieving 60.1 mg Fe/100 g w.b. after 510 min of process, in contrast to 34.4 mg Fe/100 g w.b. when the beans were hydrated without ultrasound. Finally, by hydrating the beans with ferrous sulfate, the cooking process was accelerated, which is desirable. However, the capacity for germination of the beans was reduced. In conclusion, the hydration process time can be used to fortify the beans with iron (and, possibly, other water-soluble nutrients). Nevertheless, future studies must be performed to determine if the incorporated iron is bioavailable and bioaccessible, as well as how relevant this approach is as a nutritional policy.

Effect of the iron biofortification on enzymes activities and antioxidant properties in germinated brown rice

This study evaluated the effects of germination and iron biofortification process on the enzymes activities and antioxidant properties of brown rice. The results showed that germination rates were increased after iron biofortification process. Accumulation of total iron in brown rice germinated in 2 g/L solution of ferrous sulfate was increased by 12.05–16.50 times compared with non-biofortified germinated brown rice. Furthermore, catalase and peroxidase activities were increased and decreased after this process, respectively. Total phenolic and flavonoid contents were significantly (p < 0.05) increased 1.29 and 3.91 times compared with brown rice seed. The antioxidant activities were notably enhanced, especially at high iron concentrations. Hence, the iron biofortification process could be highly beneficial to improve the antioxidant capacities in brown rice. Total phenolic and flavonoid contents had a great correlation with DPPH and ABTS radical scavenging activities in cultivar Teyou 458 (r = 0.9132–0.9439) but were not related to ferric reducing antioxidant power (FRAP) values. Moreover, in the same experiment, rice varieties had a great influence on the experimental results under the same iron biofortification conditions. This study concluded that cultivar Teyou 128 biofortified with 0.25 g/L ferrous sulfate solution during the germination process is appropriate to make functional food for human consumption.

Correlation of Chemical and Electrochemical Catalysis-Importance of Half Reactions: The Case of Catalytic Oxidation of Ferrous Sulfate by Molecular Oxygen

Catalytic oxidation of ferrous sulfate with molecular oxygen in 0.5 M H2SO4 has been studied on carbon supported platinum catalyst. Analysis of this catalytic chemical reaction as two distinct electrochemical half reactions proceeding on the catalyst surface is presented. Further, it is proposed that the catalytic chemical reaction can be studied based on mixed potential theory. Pertinent results for the proposal are presented in terms of conversions to ferric ions and the potential acquired by the electrode when immersed in an oxygen saturated solution of ferrous sulfate (mixed potential). The two individual half reactions have been studied separately to obtain key electrochemical parameters through rotating disk electrode experiments. A theoretical approach is also presented that would enable analysis of the catalytic chemical reaction through few electrochemical parameters. The results obtained clearly demonstrate that a greater understanding of various mechanistic aspects of a catalytic chemical reaction can be achieved if it is studied as two or more distinct electrochemical half reactions connected through an electron transfer mechanism.