Permanganate Titration Research Articles

Characterization of Glucomannan and Ca-Oxalate from Porang Flour (<i>Amorphophallus muelleri </i>Blume) as Candidates for Hydrogel Materials

Porang (Amorphophallus muelleri Blume), a plant belonging to the Araceae family, has the main content of glucomannan and calcium oxalate which is quite high. This study aims to determine the characteristic values ​​of glucomannan and calcium oxalate content from porang flour so that it can be used for various applications, especially hydrogel. The characteristics of glucomannan obtained from porang flour will be compared with commercial glucomannan from konjac using 3,5-DNS analysis, permanganate titration method, Fourier Transforms Infrared spectroscopy (FTIR), and Scanning Electron Microscopy (SEM). The results showed that the glucomannan content of porang flour was 99.84% dry basic (db) and the calcium oxalate content of porang flour was 0.005% wet basic (wb). The characterization results show that the glucomannan content in porang flour is higher than the commercial glucomannan content from konjac, so that porang flour has good potential as a candidate for hydrogel materials.

Quantitative Determination of the Amount of Copper(I) Oxide in the Corrosion Products Formed on Copper by the Potassium Permanganate Titration Method

In the present work, an improved titration method, called the potassium permanganate titration, was developed to quantitatively measure the mass of copper(I) oxide in the corrosion products formed on copper. This method can accurately measure the mass of copper(I) oxide on the copper surface, and the error is within +/- 3%, which was calibrated by microgravimetry. The accuracy of this improved method is higher than other current commonly used methods for determining the amount of copper(I) oxide. The effect of oxygen on the accuracy of the measurements was studied, which determined whether the operating environment of each step was in an aerobic or anaerobic environment. It was verified that ammonia can act as the solvent to completely dissolve the corrosion products without damaging the copper matrix. The amount of the copper(I) oxide formed on copper surface was also measured using this method. The potassium permanganate titration is particularly applicable to determine the amount of copper(I) oxide on the copper exposed in atmospheric environments in the absence of chloride ions.

Evaluation of Proximate, Minerals, Vitamins and Antinutrient Composition of Combretum platypterum (Welw.) Hutch. & Dalziel. (Combretaceae) Leaves

Background: Combretum platypterum (Welw.) Hutch. & Dalziel. (Combretaceae) leaves are used in treatment of jaundice and hepatitis in South-Eastern Nigeria. Evaluations of the nutritional composition of medicinal plants can enhance their profile as sources of food and medicines. This research aims to determine the proximate composition, minerals, vitamins, and anti-nutrients contents of Combretum platypterum (Welw.) Hutch. & Dalziel (Combretaceae) leaves.
 Methods: Proximate, minerals, and vitamins analysis are done according to the standard methods described by AOAC. Spectrophotometric methods and AAS were used to determined minerals. For the ANFs, oxalate concentration was determined using the permanganate titration method, phytate determination was based on the analysis of phosphorus in a ferric phytate complex, assuming a constant 4Fe: 6P molecular ratio in the complex. Tannins, trypsin inhibitors, and hemagglutinins were evaluated using other standard methods. 
 Results: Mineral content: Cal 1.14 mg/100g, Mg1.58 mg/100g, Mn 0.268 mg/100g, Cu 0.176 mg/100g, Zn 5.9 mg/100g, Se 0.957 mg/100g, Fe 3.596 mg/100g, K 1.537 mg/100g, Na 0.6 mg/100g, phosphorus 0.58mg/100g. Proximate analysis: protein 3.327 %, moisture 4.45 %, ash 2.65%, fibre 4.3%, fat 2.20 %, carbohydrates 83.07 %. Anti-nutrients content: oxalate: 0.577mg/100g, phytate 0.567mg/100g, hemagglutinin 0.428HU/mg, tannins 123.53 mg/100g), trypsin inhibitor 0.647±.003HIU/mg. Vitamin analysis: Vitamin C 0.328 mg/100g, vitamin D 0.227 mg/100g, vitamin E 0.59 mg/100g, vitamin K 0.137 mg/100g, and vitamin A (retinol) 4.507 µg/g 
 Conclusion: Combretum platypterum (Welw.) Hutch. & Dalziel (Combretaceae) leaves are rich in proximate elements, vitamins and essential minerals and low levels of antinutrients.

The Effect of Concentration and Type of Immersion Media (Water, Alcohol, Salt, and Vinegar Acid) on Decreasing Oxalate Levels in Porang

Porang tubers (Amorphophallus oncophyllus) contain very high levels of glucomannan and have many benefits in various fields of health, pharmaceuticals, industry, and food. Apart from having great benefits, porang tubers contain calcium oxalate which can cause itching if consumed directly, irritation, and kidney stones. This study aimed to determine the decrease in oxalate levels in porang tubers using various concentrations and types of immersion media in porang. The types of immersion media are water, salt, alcohol, and vinegar. Water immersion was carried out at 30°C, 40°C, 50°C, 60°C, and 70°C. Immersion with salt was carried out at concentrations of 6%, 8%, 10%, 12%, and 14%. Immersion with alcohol was carried out at concentrations of 20%, 30%, 40%, 50%, and 60%. The vinegar immersion was carried out at concentrations of 10%, 15%, 20%, 25%, and 30%. Oxalate levels were analyzed by the permanganate titration method. The results of immersion porang with dice and long slices in this study showed that water with a temperature of 50°C in the 5th immersion, alcohol with a concentration of 60% in the 5th immersion, salt solution with a concentration of 14% in the 5th immersion, and acetic acid with a concentration of 30% in the 5th immersion is the optimal result.

Nutritional composition of some selected, unprocessed amaranth grain (Amaranthus spp) varieties in Nigeria

The Amaranth grain is highly nutritious, yet it is hardly utilized in Nigeria. This study seeks to evaluate the nutritional composition of the various Amaranth grains available locally within the country. Five identified varieties were obtained from a research institute in Nigeria and a variety from the market in Ondo State, Nigeria. The six varieties were sorted separately and cleaned manually prior to grinding into flour and then subjected to chemical analysis which included proximate content, minerals, and anti-nutritional composition. An investigation of the constituting proximate, minerals and anti-nutritional compositions of the grain flours was conducted, using standard procedures. Proximate composition was determined using the Association of Official Analytical Chemists (AOAC) methods, carbohydrates were determined by difference, energy content was determined using bomb calorimetry model, mineral analysis were done using atomic absorption spectrophotometer and flame photometer while the anti-nutrients were determined using potassium permanganate titration method and spectrophotometrically. The results were analyzed using ANOVA (p ˂ 0.05) which showed significant difference between the moisture content of the market sample and other types (9.50 – 12.13%). Also, the fat and crude fibre contents of Amaranth grain flour ranged from 5.84 to 21.06 % and 0.61 to 2.07 %, respectively. Though the protein contents of the flour samples were not significantly different (14.36 – 16.03%) from each other, the mineral composition (calcium 193.34 – 247.91 mg/100g, magnesium, 65.59 – 73.48 mg/100g, manganese 6.13 – 13.24 mg/100g, sodium 360 – 435 mg/100g) was relatively high. The anti–nutrient composition showed that the varieties were low in phytate and the values ranged from 0.21 –1.74 mg/100g, the oxalate level of the varieties averaged 15.02 mg/100g for the six samples, the tannin level ranged from 9954.6 to 13565 mg/100g. The study showed that Amaranth grain flour is potentially a food commodity item for value addition either by its lone use or in composite flour formulation. Key words: Amaranth grain flour, Proximate analysis, Protein content, Minerals, Anti–nutrients, Nigeria

Investigation of Glyphosate Removal from Aqueous Solutions Using Fenton-like System Based on Calcium Peroxide

Glyphosate [N-(phosphonomethyl)-glycine], an organophosphate broad-spectrum herbicide, is a serious environmental contaminant that poses a significant threat to humans. It can be detected as a contaminant in water; thus, effective procedures for its removal are urgently required. The present study investigated the performance of glyphosate removal from aqueous solutions using a Fenton-like system. Calcium peroxide (CaO2) was used as a source of hydroxyl free radicals with Fe2+ as a catalyst to trigger the Fenton reaction. Fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), and potassium permanganate titration were carried out for characterization of calcium peroxide. The effect of operating parameters such as pH, the molar ratio of Ca2+:Fe2+, the initial dosage of calcium peroxide, and the initial glyphosate concentration on the removal efficiency was studied, respectively. The maximum total phosphorus (TP) and chemical oxygen demand (COD) removal were 94.50% and 68.60%, respectively, within 120 min under optimal conditions (pH = 3.0, initial glyphosate concentration = 50 ppm, initial CaO2 dosage = 0.5 g, molar ratio of Ca2+:Fe2+ = 6, room temperature). Experimental data were analyzed using zero-order, first-order, second-order, and Behnajady, Modirshahla, and Ghanbary (BMG) kinetics models. The degradation kinetics of glyphosate could be mostly fitted with the BMG kinetics model. This study demonstrated that calcium peroxide could be considered an effective oxidant for glyphosate wastewater treatment.

Investigation of glyphosate removal from aqueous solution using calcium peroxide

Glyphosate, an organophosphate herbicide containing carboxyl group, is widely used in agriculture. It can be found as a contaminant in water, and procedures are required for its removal. The present study investigated the efficiency of glyphosate removal from aqueous solutions using a Fenton-like system. Calcium peroxide (CaO2) was used as a source of hydroxyl free radicals with Fe2+ as the catalyst to trigger Fenton reaction. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and potassium permanganate titration were carried out for characterization of calcium peroxide. The effect of operating parameters such as pH, molar ratio of Ca2+: Fe2+, and initial dosage of calcium peroxide on the total phosphorus (TP) removal efficiency was studied. The maximum TP removal was 94.50% under optimal conditions (pH = 3.0, initial glyphosate concentration = 50 ppm, initial CaO2 dosage = 0.5 g, molar ratio of Ca2+: Fe2+= 6). This study demonstrated that calcium peroxide could be considered as an effective oxidant for glyphosate wastewater treatment.

Modification of Microfluidic Paper-Based Devices with an Oxidant Layer for Distance Readout of Reducing Substances.

We developed a novel strategy for modification of paper cellulose with water-insoluble oxidants for distance readout of reducing substances on microfluidic paper-based analytical devices (μPADs). Water-insoluble oxidants were formed and modified onto paper cellulose through the redox reaction that occurred between paper cellulose and potassium permanganate deposited on the paper channel, developing a yellowish-brown color on the channel. As aqueous solutions containing reducing substances flowed along the channel, reducing substances were consumed owing to the redox reaction that occurred between oxidants and reducing substances until the reducing substances were depleted, forming a discolored zone on the yellowish-brown channel. The redox reaction between insoluble oxidants and reducing substances on the paper cellulose could be used for distance-based detection of a wide variety of reducing substances, which is similar to the classical potassium permanganate titration that employs the redox reaction that occurred between potassium permanganate and reducing substances. We believe that this method will broaden the analytical applications of distance-based detection on μPADs. This method was applied to ascorbic acid assay and captopril assay in real samples with analytical results comparing well with the labeled values, demonstrating its great potential in real sample analysis.

The effect of synthesis method on oxygen nonstoichiometry and electrical conductivity of Sr-doped lanthanum manganites

The strontium-doped lanthanum manganites (La1-xSrxMnO3, LSMO) have potential use in devices for energy conversion and storage due to their chemical stability and high electrical conductivity. In this study, LSMO (x = 0, 0.1, 0.2, 0.3) were prepared by the citrate-nitrate autocombustion (CNA) and coprecipitation synthesis. The formation of the LSMO phase was confirmed by X-ray diffraction and the lattice parameters were determined by Rietveld refinement analysis. The oxygen nonstoichiometry in samples was determined by permanganate titration. The results of electrical conductivity measurement have shown semiconductor behaviuor in all samples, with conductivity rising with temperature and Sr-amount. Furthermore, it was observed that LSMO samples prepared by the coprecipitation method possess higher conductivity than samples prepared with the CNA method due to the higher oxygen nonstoichiometry. Electrical conductivities of all LSMO samples were in 10−2–0.45 Ω−1 cm−1 range, which is comparable to the conductivity of Si.

Simultaneous oxidation of aromatic compounds using Sr‐doped lanthanum manganites as catalysts

Strontium-doped lanthanum manganites, La1-xSrxMnO3 (LSMO), are promising and affordable catalysts for oxidative degradation of volatile organic compounds. LSMO catalysts (x = 0, .1, .2, and .3) were prepared by the citrate-nitrate autocombustion (CNA) and coprecipitation synthesis. The phase composition was confirmed by X-ray diffraction and Rietveld refinement analysis, while the oxygen content was determined by Mohr's salt permanganate titration. Morphology and porosity of prepared catalysts was correlated to catalytic oxidation of benzene, toluene, ethylbenzene and o-xylene. It was observed that both synthesis methods yielded catalysts of similar average pore size diameter and specific surface area, but the pore size distribution differed: CNA-prepared catalysts had a multimodal pore size distribution, while the coprecipitated ones had a single maximum at 4 nm. Catalysts prepared by the CNA method have shown a higher catalytic activity in the temperature range 373–723 K, as the presence of Mn3+/Mn4+ mixed valences increased their reducibility.

Evaluation of some analytical methods for determination of calcium oxalate in Amorphophallus muelleri flour

The presence of calcium oxalate is the major obstacle in flour processing of Amorphophallus muelleri tuber since the calcium oxalate can induce skin irritation and is harmful to kidneys. The development of a rapid analytical method to detect calcium oxalate in Amorphophallus flour is required. This research was intended to evaluate the use of some analytical methods (FTIR, SEM-EDS, XRD, XRF, and titration methods) in calcium oxalate detection in Amorphophallus muelleri flour prepared from different treatments (soaking in water (W), solution of sodium bisulfite 1000 ppm (B), solution of sodium chloride salt 3% (S), solution of sodium bisulfite 1000 ppm and sodium chloride salt 3% (BS)). Results showed that the presence of oxalate in Amorphophallus flour can be detected in the FTIR spectra from the C=O group at a wavenumber of 1610 cm-1. SEM images confirmed that calcium oxalate in Amorphophallus flour existed as raphide crystals in which their quantity can be estimated by the EDS feature of SEM. The presence of calcium oxalate crystals in Amorphophallus flour can be differentiated from other salts present in the flour by XRD. XRF can be used as a rapid analytical tool to detect the presence of calcium oxalate in Amorphophallus flour. The potassium permanganate titration technique can be used as a reference method for other rapid analytical methods in detecting calcium oxalate in Amorphophallus flour.

Utilization of HVS Paper Waste for The Manufacture of Oxalic Acid

The purpose of this research is to determine the effect of time and temperature on the manufacture of oxalic acid from HVS paper waste by removing ink and alkali melting methods The research methodology began with the first stage, namely pre-treatment and then paper hydrolysis, weighing 600 grams of HVS paper waste. The HVS paper waste was put into a three-neck flask and 200 mL of 40% NaOH was added. The tools are assembled and set the time and temperature used. The time used is 60 minutes at a temperature of 55°C, 65°C, 75°C and 95°C, then a three-neck flask is heated. After heating is complete the solution is cooled. The filtrate was filtered into a 500 mL beaker glass then the remaining sediment was washed with hot aquadest into a beaker containing up to 400 mL of filtrate. The procedure was repeated for variations in time of 70, 80 and 90 minutes at temperatures of 55°C, 65°C, 75°C and 95°C, respectively. The second stage is crystallization of oxalic acid, pipette of the filtrate as much as 25 mL obtained from the hydrolysis results then added 10% CaCl2 to form a white precipitate of calcium oxalate. The precipitate was filtered then added 100 mL of H2SO4 4N so that the precipitate would break down into oxalic acid and calcium sulfate, then filtered and washed the remaining sediment using 96% ethanol. The filtrate is heated to a temperature of 70°C. The filtrate is cooled in ice water for about 24 hours to form oxalic acid crystals in the form of white needle crystals. The third stage is the calculation of the weight of oxalic acid (gr). The fourth stage is testing for oxalic acid using permanganate titration. Oxalic acid crystals were weighed as much as 0.3 grams then added 10 mL of distilled water and put into 250 mL Erlenmeyer, added 10 mL of H2SO4 4N. The solution is heated to a temperature of 60-70°C. In a hot state, the solution is titrated with 0.1 N potassium permanganate until the solution appears a pink color that does not disappear for 30 seconds. The fifth stage is the calculation of the yield (yield) of oxalic acid. The sixth stage is the melting test. The time and temperature in producing oxalic acid from the graph can be seen that the average temperature that produces the most oxalic acid is at 80 minutes and 65°C, which is 3.9 grams. The analysis results show that the melting point obtained is between 100-101 ° C. This happens because the oxalic acid in the research indicates that the oxalic acid corresponds to the actual melting point of oxalic acid based on the Indonesian National Standard (SNI), namely 101-102°C.

Characterizations of a Plasma-Water System Generated by Repetitive Microsecond Pulsed Discharge with Air, Nitrogen, Oxygen, and Argon Gases Species

A non-thermal plasma-water system using a microsecond pulsed high-voltage power supply was investigated with air, nitrogen, oxygen, and argon gas feedings individually. Optical emission spectroscopy (OES) was utilized to characterize the primary active species inside the plasmas generated by different gas feedings. The OES method was also employed to estimate the neutral gas and electron temperatures. The pH and the oxidation-reduction potential (ORP) of plasma-activated water (PAW) were measured in the liquid phase. An ion chromatography system (ICS) was employed to present the PAW activity, such as nitrite and nitrate species. Moreover, hydrogen peroxide as a secondary active species inside the activated water, generated by the gases mentioned above, was measured by potassium permanganate titration. It was found that the gas species have a noticeable effect on the pH level as well as the ORP of PAW. In the cases of argon and oxygen plasmas, the pH level of PAW does not change significantly. In contrast, the pH values of PAW generated by air and nitrogen plasmas decline sharply during the treatment time. Moreover, the gas species have a significant impact on the concentrations of nitrite, nitrate, and hydrogen peroxide generated in PAW. The activated water generated by oxygen plasma provides the highest level of hydrogen peroxide. Although the consumed power of argon plasmas was half of the other plasma sources, it provides relatively high hydrogen peroxide contents compared to the nitrogen and air plasmas.

Efficacy and Safety of Bleaching Gels According to Application Protocol.

This study evaluated bleaching efficacy, enamel microhardness, and roughness of highly concentrated hydrogen peroxide (HP) gels (35%-40%) using different application protocols. Gel decomposition and pH alteration were also analyzed. Bovine enamel/dentin specimens were divided into groups according to the bleaching gel-Pola Office Plus (POP-SDI, 37.5% HP), Opalescence Boost (OPB-Ultradent, 40% HP), Whiteness HP (WHP-FGM, 35% HP)-and application protocol-single application (SA) and multiple application (MA) during the in-office session. Deionized water was used in control group (no bleaching). Thus, seven final groups were obtained (n=15/group). Color (CIE L*a*b*), surface microhardness (SMH), and roughness (Ra) were assessed before/after treatments. The pH of gels was measured, and HP concentration was determined with potassium permanganate titration method in different times. Data were submitted to analysis of variance and Tukey tests (5%). All gels presented similar and clinically acceptable bleaching efficacy (ΔE>2.7) for both SA and MA, as well as no significant differences for SMH and Ra comparing the two protocols in the same gel. Peroxide decomposition significantly increased with time, but final gel concentrations were still high after 45 minutes (32.29% POP; 38.45% OPB; and 32.74% WHP). The pH decreased over time (initial - after 45 min) for WHP (6.83±0.07 - 5.81±0.06), but minimal alterations were observed for POP (8.09±0.09 - 7.88±0.07) and OPB (7.82±0.11 - 7.87±0.07). Peroxide decomposition was very low for all gels tested, and pH remained stable for POP and OPB gels. Bleaching protocol did not influence whitening efficacy and hazardous effects over enamel, thus potentially there was no clinical significance. Therefore, for the products tested, there is no evidence for recommending the gel change during the bleaching session.

Permanganometric determination of oxygen nonstoichiometry in manganites

Strontium and lanthanum manganites are nowadays the subject of extensive research because of their promising electrical and magnetic properties. Strontium manganite, SrMnO3, was successfully prepared by citrate-nitrate autocombustion (CNA) and by the coprecipitation method. These methods were then applied to synthesis of strontium doped lanthanum manganites, La1-xSrxMnO3 (x ​= ​0, 0.1, 0.2 and 0.3). The optimal phase formation conditions were determined by thermogravimetry and differential scanning calorimetry. Crystallization of precursors and calcined powders was studied by X-ray diffraction. Powders, in which pure manganite phase was obtained, were also analyzed by permanganate titration with Mohr’s salt in order to determine oxygen nonstoichiometry. Oxygen stoichiometry was achieved in SrMnO3 powders obtained by the CNA method and calcined at 1000 ​°C as well as in powders obtained by the coprecipitation method and calcined at 1200 ​°C. La1-xSrxMnO3 phase was oxygen stoichiometric for x ​= ​0.3 while decreasing of x resulted in cation deficiency, i.e. oxygen excess. Oxygen deficit was achieved for x ​= ​0.09 upon calcination at 1200 ​°C. The obtained results were confirmed by thermogravimetry and the Rietveld refinement analysis.

The oxidation reaction and sensitivity of aluminum nanopowders coated by hydroxyl-terminated polybutadiene

ABSTRACT The aluminum nanopowder (nAl) was coated using hydroxyl-terminated polybutadiene (HTPB) as a coating agent. The morphology and structure of the coated samples (nAl/HTPB) were characterized by Transmission Electron Microscope (TEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). The active aluminum content of nAl and nAl/HTPB was measured by potassium permanganate titration methods and thermogravimetry (TG). The oxidation processes at high temperature were studied by thermogravimetry and differential scanning calorimetry (TG–DSC). The results indicated that the coated nAl showed core-shell structure, and HTPB can prevent the oxidation of nAl to a certain extent. The coating agent has an effect on the oxidative exothermic reaction temperature of aluminum powder, especially in high-temperature range. Due to the simultaneous action of HTPB and nAl, both the exothermic rate and exothermic calorific value increase. The thermal decomposition kinetics of nAl and nAl/HTPB was studied by the Kissinger method and the Ozawa method. The results showed that the average activation energies of nAl and nAl/HTPB were 428.05 and 300.8 kJ·mol−1, respectively. Mechanical sensitivity shows that the coating of HTPB is good to the friction and electrostatic sensitivity of nAl to a certain extent but not to the impact sensitivity.

Effects of dexmedetomidine pretreatment on rats with sepsis-induced acute kidney injury and miR-146a expression

The current research aimed to study the effects of dexmedetomidine (DEX) pretreatment on rats with sepsis-induced acute kidney injury (SAKI) and miR-146a expression. The model of SAKI was established through the tail vein injection of lipopolysaccharide (LSP). We used an automatic biochemical analyzer to detect serum urea nitrogen (BUN) and creatinine (Cre) levels. The expression levels of urine KIM-1 and NGAL and serum IL-1β and IL-6 were analyzed by enzyme-linked immunosorbent assay (ELISA). The content and activity of superoxide dismutase (SOD) were detected by the xanthine oxidase method. The content of malondialdehyde (MDA) was determined by the thiobarbituric acid (TBA) method. Reactive oxygen species (ROS) was detected by fluorescent probe DCFH-DA. Catalase (CAT) was detected by potassium permanganate titration. The expression level of miR-146a in the renal tissue and serum was detected by RT-PCR. The expression levels of Nrf2 and HO-1 proteins were detected by Western blot. Compared with those in the model group, rats in the DEX group had significantly lower expression levels of serum BUN, Cre, IL-1β, and IL-6, and oxidant markers MDA and ROS, but significantly higher expression levels of miR-146a and antioxidant markers SOD and CAT. DEX pretreatment could improve the kidney morphology, injury severity, and Nrf2 and HO-1 proteins of rats with SAKI. In conclusion, DEX can improve oxidative stress and inflammatory responses in rats with SAKI, reduce the severity of the renal injury, and up-regulate the expression level of miR-146a.

Characterization of radiolytically synthesized feroxyhyte and oxidized magnetite nanoparticles

Iron(III) chloride deaerated alkaline aqueous colloidal solutions in the presence of 2-propanol and DEAE-dextran (diethylaminoethyl-dextran hydrochloride) were γ-irradiated with doses of 36 and 130 kGy. The dose rates were ~7 and ~31 kGy h−1. The extremely stable aqueous suspension of substoichiometric Fe2.83O4 magnetite nanoparticles ~4.7 nm in size were formed at a dose rate of ~7 kGy h−1 and at a dose of 36 kGy. At a dose of 130 kGy the anisotropic δ-FeOOH magnetic discs with a diameter of ~256 nm and thickness of ~40 nm were formed. Each disc has a substructure consisting of approximately eighteen laterally stacked thin nanodiscs of about 2.2 nm in thickness. At a higher dose rate of ~31 kGy h−1and at a dose of 36 kGy, XRD revealed the presence of highly substoichiometric Fe2.75O4 magnetite, whereas TEM analysis revealed the presence of ~4.3 nm magnetite nanoparticles along with rod-shaped γ-Fe2O3 nanoparticles. The values of isomer shift in Mössbauer spectra of about 0.33 mm s−1 showed that all Fe(II) in substoichiometric magnetites oxidized to Fe(III) one month after synthesis. At high dose and dose rate, the rolled rod-like δ-FeOOH magnetic nanoparticles were formed having the diffraction patterns with streaks, which are characteristic of tubular structures. The magnetic measurements showed exceptional intrinsic room-temperature magnetic properties of both δ-FeOOH nanostructures with the Curie temperature above 300 K. In order to ascertain the formation of Fe(II) intermediate products prior to their oxidation, γ-irradiated samples were isolated by admixing glycerol. The amounts of Fe(II) in glycerol-isolated solid samples were determined using Mössbauer spectroscopy. Carbonate Green Rust I [GR(CO32−)] and Fe(OH)2 intermediate phases were confirmed by XRD and Mössbauer spectroscopy. The amounts of Fe2+ in the acidified solutions containing dissolved γ-irradiation ferrous products were determined using the potassium permanganate titration. The amounts of Fe2+ were 68.9% and 96.1% at doses of 36 and 130 kGy, respectively. Thus, at a dose of 130 kGy the radiolytically generated Fe(OH)2, after coming in contact with oxygen and CO2 from the air, topotactically oxidized to GR(CO32−) and further to δ-FeOOH without any structural changes. The lower dose rate (~7 kGy h−1) favored the δ-FeOOH nanodisc morphology, whereas the higher dose rate (~31 kGy h−1) favored the formation of tubular rod-like δ-FeOOH nanoparticles.

Estimation of Oxalate Content of Bottle Gourd Leaves

Bottle gourd leaves are widely used as animal feed in India. Consumption among the human beings, especially in low income group people are also found. But many of the leafy vegetables contain oxalate which may have hindering effect on the absorption of some important minerals like Calcium, Iron etc in human body. In this present study total oxalate content of bottle gourd leaves ( Lagenaria siceraria ) has been estimated by permanganate titration method. The result shows that the oxalate content of bottle gourd leaves ( Lagenaria siceraria ) is 49.086mg/100gm. The oxalate contents of some of the common leafy vegetable are also compared to the bottle gourd leaves ( Lagenaria siceraria ). From this study it may be concluded that oxalate content of bottle gourd leaves is much lower than that of other leafy vegetables.

Improvement of the technique of quantitative determination of chlorogenic acid in shrot from sunflower seeds

In the article the useful properties of compounds – antioxidants in relation to fatty foods and the human body in general reviewed. It is noted that there are antioxidants by nature and the mechanisms of their action described. In addition, the choice of sunflower meal as a raw material for the production of antioxidants and the exact antioxidants contained in the meal are substantiated. These include polyphenolic compounds, and in particular chlorogenic acid, which amounts to 43-73% of all polyphenolic compounds isolated from sunflower kernels and 1-4% of sunflower meal. The methods of quantitative analysis of polyphenolic compounds - antioxidants are considered, and, taking into account the advantages and disadvantages, one of them was chosen for further research – the method of permanganate titration, which is based on oxidation of phenolic compounds with potassium permanganate with indigoquarmine as an indicator. The end of the reaction is determined by the disappearance of the green tint and the appearance of pure yellow color. The chosen method has been improved in order to eliminate the difficulties in determining the end of the reaction. To save time and amount of solvent, preparation of a sample of copper for the removal of polyphenolic compounds and, in particular, chlorogenic acid has also been improved with the help of central composite orthogonal planning of the second order, followed by mathematical modeling in the MathCad software package. Series of experiments on extraction of chlorogenic acid from sunflower oil was carried out in a single stage in a flask with a back fridge in a boiling water bath. The optimal conditions of the extraction process were determined: the concentration of the aqueous solution of ethyl alcohol is 60%, the hydrostructure of the meal: the solvent 1:90, the duration of extraction – 30 minutes. Under these conditions, the mass fraction of chlorogenic acid is 7.99%. (Considering that the mass fraction of chlorogenic acid in sunflower meal under traditional extraction conditions is 6.80 %.) Determination of optimal parameters of the extraction process of phenolic compounds allowed to significantly reduce the length of the preparation process, reduce the cost of extractant-ethanol solution and increase the yield of the final product in comparable to the known traditional method