Trace Amounts Of Manganese Research Articles

The Effects of a Trace Amount of Manganese and the Homogenization on the Recrystallization of Al-7Mg-0.15Ti Alloys.

The aim of this study is to explore the effects of Manganese addition and homogenization treatment on the microstructures and mechanical properties of the Al–7Mg–0.15Ti (B535.0) alloy. The optical microscopy, electrical conductivity measurements, transmission electron microscopy, scanning electron microscopy (SEM + EBSD), as well as Rockwell hardness and tensile tests, were exploited for this purpose. The main objectives are to refine the grain size, inhibit grain growth in the annealed state, and enhance the mechanical strength of the alloy. The results show that the addition of manganese to the Al–7Mg–0.15Ti alloys refined the as-cast and recrystallized grains of the alloys. During the homogenization process, Al4Mn high-temperature stable dispersoids were precipitated in the aluminum matrix. After annealing, the Al4Mn particles blocked the movement of grain boundaries during the growth of the recrystallized grains and inhibited grain growth. Consequently, the annealed alloys showed grain refinement and dispersion strengthening. The Al4Mn dispersoids of the alloys with manganese added were smaller and denser after a two-stage homogenization process compared to those that underwent a one-stage homogenization process. By contrast, for the alloys without the addition of manganese, the recrystallized grains showed normal growth after annealing, and different homogenization processes had no significantly different effects.

Development and characterization of nano- flux welding powder from calcined coconut shell ash admixture with FeO particles

This work presents a novel nanoparticle flux powder Iron Oxide (FeO) developed from coconut shell through the chemical reduction. The analysis and the characterization of morphology and chemical properties of the developed flux powder and control were examined using Scanning Electron Microscopy, Elemental Dispersive X-ray, Transmission Electron Microscopy, and X-ray Powder Diffraction. From the results, the powder was found to contain 45.82% Iron, 44.38% carbon, 8.86% oxygen and trace amounts of manganese, Aluminum, and silicon while the control flux powder was found to contain 57.1% Fe, 23.3% O and 7.3% C which confirmed the flux powder as Iron Oxide based type. Digitizer image confirmed that the area of the particle’s sizes was in the nanometric range with the largest particle being 240 nm2 and the smallest being 9 nm2 and areas ranging from 1.319 to 490.57 nm2 compare to control. The X-Ray diffraction contains various phases of Fe with the most prominent groups wavelength 9.26. For the developed nano-flux welding powder, at 2ϑ = 38°, the value of FWHM, i.e. ∝ was found to be 0.275°, and the Dislocation density (δ) value was found to be 9.8269 × 1014 (Lines/m2), the d spacing was computed to be 2.355 Å, the Micro Strain (ε) value was 6.497 × 10−2 while the Crystallite size was 31.9 nm at hkl (111). The results confirmed that flux powder can be produced from agro-waste with better properties and applications.

Determination of manganese(VII) as 3,3′-Dianisole-4,4′-bis(3,5-diphenyltetrazolium chloride) complex and its application

A simple, rapid, selective and sensitive spectrophotometric method is described for the determination of trace amounts of manganese using Blue tetrazolium chloride as a chromogenic reagent. The method is based on the formation of ion-associate complex between manganese(VII) and the cation of ditetrazolium salt, having an absorption maximum at 255 nm. Beer’s law is obeyed in the range of 0.1–1.6 μg mL−1. The molar absorptivity and Sandell’s sensitivity were found to be 4.97 × 104 L mol−1 cm−1 and 1.11 × 10−3 μg cm−2, respectively. Limit of deterction is 6.86 ng mL−1 Mn(VII) and limit of quantitation is 22.8 ng mL−1 Mn(VII). Optimum reaction conditions were evaluated. The effect of interfering ions on the determination is described. The extraction, distribution and association constants, and the recovery factor have been calculated.

Pre-concentration of trace amounts of manganese in water samples based on (1-(2-pyridylazo)-2-naphthol) modified magnetic nanoparticles

A simple procedure based on magnetic nanoparticles has been developed for analytical purposes. In this method, 1-(2-pyridylazo)-2-naphthol (PAN)-modified magnetic nanoparticles (MNPs) were used for separation and pre-concentration of manganese(II) ions from aqueous samples. This method combines the use of a solution solvent with separation of magnetic nanoparticles from sample solution using a magnet. The influence of different parameters, such as amount of extractant (PAN) loaded on the nanoparticles, pH of solution, adsorption time, amount of modified nanoparticle, type and amount of eluents for desorption of manganese from magnetic nanoparticles were evaluated. The effect of various cationic and anionic interferences on the percentage recovery of manganese was also studied. Manganese ions were adsorped from a solution at pH 9.5 and desorbed from nanoparticles with 10 mL of DMSO : HNO3 (1 : 1, v/v). The detection limit of the proposed method was found to be 0.11 µg L−1. The method was employed to recover and determine the level of manganese in different water samples.

Extraction-spectrophotometric study of the system manganese(VII)-methyl violett-water-chloroform and its application

The system manganese(VII)-methyl violet(MV)-water-chloroform has been studied. The composition of the complex is established as MV: MnO4−=1:1. The molar absorptivity of the complex is (2.67 ± 0.09) × 104 l mol−1 cm−1 at 300 nm, limit of detection is 0.027 μg ml−1 and the system obeys Beer’s law in the range 0.22–1.6 μg ml−1 Mn(VII). The characteristic values for the extraction equilibrium and the equilibrium in the aqueous phase was determined. The influence of foreign ions on the accuracy of the results is investigated. Extraction investigations of the system discussed were carried out. A new rapid, selective, simple and sensitive extractive-spectrophotometric method for the determination of trace amounts of manganese(VII) in plants, soils and steels were developed.

Determination of Trace Amounts of Lead and Manganese in Water Samples After Simultaneous Preconcentration onto Modified Amberlite XAD-4 Resin

A procedure for simultaneous separation and preconcentration of trace amounts of manganese and lead has been proposed. It is based on the adsorption of manganese and lead ions onto a column of Amberlite XAD-4 resin loaded with pyrocatechol reagent. Manganese and lead were quantitatively retained on the column in the pH range 4.0-6.5 at a flow rate of 2 mL/min. The manganese and lead ions were eluted with 5.0 mL of 4 M HNO3 solutions. Manganese and lead were measured by flame atomic absorption spectrometry. In this case, 100.0 ng manganese and 1000.0 ng lead were concentrated in the column from 800 mL of aqueous sample, where their concentrations were as low as 0.125 and 1.25 ng/mL, respectively. Seven replicate determinations of mixtures of 1.0 microg/mL manganese and 2.0 microg/mL lead in the final solution gave a mean absorbance of 0.1926 and 0.0832 with RSD values of +/- 1.1 and +/- 1.2%, respectively. The LODs were 1.76 ng/mL for Mn(ll) and 37.28 ng/mL for Pb(ll) (3 delta(bl)/m) in the final solution, with a preconcentration factor of 160. Sensitivities for 1% absorbance for Mn(ll) and Pb(ll) were 7.0 and 74.7 ng/mL, respectively. The interference of a large number of anions and cations has been studied and the optimized conditions were used for determination of trace amounts of manganese and lead in various environmental and standard samples.

Preconcentration of trace cadmium and manganese using 1-(2-pyridylazo)-2-naphthol-modified TiO2 nanoparticles and their determination by flame atomic absorption spectrometry

A new method has been developed for the preconcentration of trace amounts of manganese and cadmium prior to their determination by flame atomic absorption spectrometry (FAAS). The method is based on using a microcolumn packed with 1-(2-pyridylazo)-2-naphthol (PAN)-modified sodium dodecyl sulfate (SDS) coated TiO2 nanoparticles as a solid-phase sorbent. Effects of pH, sample flow rate and volume, elution solution and interfering ions on the recovery of the analytes have been investigated. The adsorption capacity of modified TiO2 nanoparticles was found to be 9.2 and 8.9 mg g−1 for Mn and Cd, respectively. The detection limits (3σ) of this method are 1.0 and 0.96 ng mL−1 for Mn and Cd, respectively. The proposed method has been applied to the determination of the elements in water samples with satisfactory results.

Analytical Studies on the Gum Exudates from Anogeissus leiocarpus

Anogeissus leiocarpus gum samples were collected randomly as natural exudates from 3 different locations in Sudan, namely Abojebiha (season 1994-1995), Elfula and Rosaries (season 1996-1997). Physicochemical properties of gum samples (moisture, ash, nitrogen, protein, specific rotation, relative viscosity, refractive index, equivalent weight, pH, uranic acid, reducing sugar and tannin content). Results showed significant differences within each location in most parameters studied except in the refractive index values which was found to be constant in all samples (1.334). The effect of location on the properties of gum samples was also studied and the analysis of variance showed insignificant differences (p<0.05) in al l properties studied except in ash content and this may be due to the differences in the type of clay soil which found in the three different locations. The general characteristics of Anogeissus leiocarpus gum might be described as the mean value of all properties studied of all gum samples of the three different location as follows: 9.2% moisture, 3.4% ash, 0.72% nitrogen, 4.74% protein%, -35.5° specific rotation, 1.68 relative viscosity, 4.2 pH, 1.334 refractive index, 14.3% uranic acid, 0.44% reducing sugar 1336.0% equivalent weight and 0.68% tannin content. UV absorption spectra of gum samples were determined and the maximum absorption points were found the same ranging between wave length 243 and 285. Cationic composition of gum samples was also determined and the results showed that magnesium (Mg) has the highest value in all samples followed by iron (Fe), sodium (Na), potassium (K), calcium (Ca), zinc (Zn) and trace amount of manganese (Mn), copper (Cu), nickel (Ni), cadmium (Cd) and lead (Pb). Functionality (water holding capacity and emulsifying stability of Anogeissus leiocarpus gum were studied. The water holding capacity value was found to be 65.5% and emulsifying stability value was found to be 1.008 insignificant differences were observed between Anogeissus leiocarpus gum and Acacia senegal gum for the 2 parameters studied.

Co-Composting of Empty Fruit Bunches and Partially Treated Palm Oil Mill Effluents in Pilot Scale

The main objective of this study is to investigate the physicochemical changes of the co-composting Empty Fruit Bunch (EFB) with partially treated palm oil mill effluent (POME) in pilot scale. The partially treated POME from anaerobic pond was sprayed onto the shredded EFB throughout the treatment. The composting materials were turned over one to three times per week for aeration. Temperature and oxygen were monitored at different depths of the composting piles. Parameters such as C, N, pH, nutrients, heavy metals and total bacteria count were also determined. The temperature was increased up to 58.5°C at day three of treatment, after that fluctuated between 50 to 62°C and then decreased in the latter stage of the process. The pH of the system (7.75-8.10) did not vary significantly during the treatment period while moisture content was reduced from 65-75% to about 60% at the end of the treatment. The initial C/N ratio of 45 was significantly reduced to 12 after 60 days of composting. The final cured compost contained a considerable amount of nutrients (carbon, nitrogen, phosphorus, potassium, calcium, magnesium, sulfur and iron) and trace amounts of manganese, zinc, copper. In addition, very low levels of heavy metals were detected in the compost. The number of bacteria involved in the composting process was decreased at the end of the composting period. The results obtained indicated that pilot scale of co-composting EFB with partially treated POME gave acceptable quality of compost and ease in operation. The compost product may useful in palm oil plantation as fertilizer and soil amendment.

Spectrophotometric determination of manganese(VII) using benzyltriphenylphosphoniumchloride as a new reagent and application of artificial neural network to extending the dynamic range of determination

A simple and selective spectrophotometric method is proposed for the determination of trace amounts of manganese. The method is based on the extraction of manganese as a MnO2-benzyltriphenylphosphoniumchloride ion pair with chloroform. An artificial neural network (ANN) has been applied to the handling of the spectrophotometric data of this complex in the organic phase to extend the dynamic range of manganese determination (0.020–6.0 μg/mL). A three-layer back-propagation network (50:75:1) was used with root-mean-square error (rmse) 0.001 and momentum (m) 0.8 overall. The application of BP-ANN makes it possible to extend the dynamic range of the determination of manganese from its narrow linear range of 0.020–2.5 μg/mL to the dynamic range 0.020–6.0 μg/mL.

IN SITU ANALYSIS OF THE INTERACTION OF MANGANESE VAPOR AND SILICA MICROSPHERES IN A LABORATORY-SCALE COMBUSTOR

To simulate and better understand toxic metal–sorbent particle interactions, laser-induced breakdown spectroscopy (LIBS) was implemented to quantify trace amounts of manganese enriched on the surface of concomitant silica microsphere particles in an optical access laboratory-scale combustion system. Flame atomic absorption measurements verified that introduced manganese nanoparticles were extensively dissociated within the high-temperature region of the H2–O2–N2–air flame. LIBS-based conditional spectral analysis was performed using the Si (I) 288.1 nm atomic emission line with a spectral window containing both silicon and manganese atomic emission lines. The presence of silicon was found to have no effect on the emission intensity of the Mn triplet near 279 nm. The enrichment of manganese on the silica particles was observed in situ using the LIBS technique. The experimental trends agree very well with the theoretical trend predicted by modeling the aerosol system by accounting for nucleation, condensation, and coagulation processes.

Preconcentration and Determination of Manganese in Water Samples UsingN,N ′-bis(2-Hydroxy-5- bromo-benzyl)1,2 Diaminopropane

Abstract The synthesis and analytical applications of N,N ′-bis(2-hydroxy-5-bromo-benzyl)1,2 diaminopropane (HBDAP) are described. The investigation includes a study of the characteristics that are essential for solvent extraction and for spectrophotometric determination and preconcentration of manganese. The organic phase loaded with Mn(II) from aqueous phase was stripped in one stage by using different mineral acid solutions. It was found that stripping efficiency was quantitative in case of HNO3. A highly sensitive, selective and rapid spectrophotometric method is described for the determination of trace amounts of manganese(II) by HBDAP. This compound reacts with manganese(II) in the range of pH 7–10 to produce a brownish complex (2:3 mol ratio of Mn(II)/HBDAP) soluble in chloroform. The complex obeys Beer's law from 0.12 to 13.2 mg L−1 with an optimum range. The relative standard deviations were % 0.02 (10 samples, each containing 3.2 mg L−1 Mn(II)). The precision was determined from 30 results obtai...

Determination of Manganese (II) in Foodstuffs by β-Cyclodextrin Polymer Phase Spectrophotometry with 1-(2-Pyridylazo)-2-naphthol

The chromogenic agent, 1-(2-pyridylazo)-2-naphthol (PAN) was included in g -Cyclodextrin polymer ( g -CDP) and the modified polymer of inclusion of PAN ( g -CDP-PAN) was obtained. Based on the fact that g -CDP-PAN can adsorb Mn (II) in solution to form Mn (II)-PAN complex, a sensitive and selective solid phase spectrophotometric method for the determination of trace amounts of Mn (II) has been developed. The maximum absorbance of Mn (II)-PAN complex in g -CDP was at 514 nm. The working range of the calibration graph was 2-12 w g of Mn (II). The interference of molybdenum, lead, cobalt, chromium, iron, nickel, zinc, tin, cadmium, and copper that form colored species with PAN in the polymer phase was investigated. The method was applied to the determination of Mn (II) in black rice and tea samples. A new method for the determination of trace amounts of manganese by polymer phase spectrophotometry is described. Manganese reacted with 1-(2-pyridylazo)-2-naphthol (PAN) that was included in a g -cyclodextrin polymer. The absorbance of the colored polymer, packed into a 5 mm quartz cell, was determined directly at 514 nm. The proposed method was applied to the determination of manganese in black rice and tea samples.

The hydantoin amidohydrolase from Arthrobacter aurescens DSM 3745 is a zinc metalloenzyme

The hydantoin amidohydrolase (hydantoinase) from Arthrobacter aurescens DSM 3745 was purified to homogeneity and subjected to metal analysis under atomic absorption spectrometry (AAS) and inductive coupled plasma–atomic emission spectrometry (ICP–AES). Three independent preparations of homogeneous enzyme indicated that 1 mol of the active enzyme contains 10 mol zinc ions. This corresponds to 2.5 mol zinc per mol subunit, since the hydantoinase consists of four identical subunits. Only trace amounts of manganese, magnesia, nickel and cobalt were detected. Other metals were either absent or existed below detection levels.

Determination of free state manganese(II) in a decoction of a traditional Chinese medicine based on a kinetic spectrophotometric method

The chemical state of trace elements in decoctions of traditional Chinese medicines is a new research subject in the chemical studies of traditional Chinese medicine. A simple and sensitive kinetic spectrophotometric method is proposed for the determination of free manganese(II). The method is based on the catalytic effect of manganese(II) on the oxidation of Malachite Green by potassium periodate. The reaction was followed spectrophotometrically by measuring the rate of change in the absorbance of the coloured Malachite Green at 615 nm. Trace amounts of manganese(II)(0.2–2 ng) can be determined with good accuracy and reproducibility; the detection limit is about 0.1 ng. Only iron(III) and aluminium(III) interfere in the determination but these can be masked by fluoride. This method has been used to analyse decoctions of traditional Chinese medicines for trace amounts of free manganese(II) without separation.

Application of a tetraaza macrocycle immobilized on an organic polymer to the determination of trace amounts of manganese in seawater: Blain, Stéphane et al., 1990. Analytica chim. Acta, 232(2):331–336. Inst. d'Etudes Mar., Univ. de Bretagne-Occidentale, 6 Ave. le Gorgeu, 29287 Brest Cedex, France

Application of a tetraaza macrocycle immobilized on an organic polymer to the determination of trace amounts of manganese in seawater: Blain, Stéphane et al., 1990. Analytica chim. Acta, 232(2):331–336. Inst. d'Etudes Mar., Univ. de Bretagne-Occidentale, 6 Ave. le Gorgeu, 29287 Brest Cedex, France

Spectrophotometric determination of manganese with dithizone using the synergistic effect of pyridine

The extraction of manganese with dithizone using the synergistic effect of pyridine has been studied. A method is described for determining manganese spectrophotometrically. Trace amounts of manganese can be determined, the sensitivity being 0.0014 μg Mn/cm 2 at 530 nm.

熱中性子による鉄鋼中微量マンガンの非破壊分析

Trace amounts of manganese in steel was determined nondestructively by neutron activation analysis using JRR-1 reactor (neutron flux: 1011 n/cm2·sec). The induced radioactivity of 56Mn was measured with a well type scintillation counter and a γ-ray spectrometer. The results were as follows: (1) The agreement between neutron activation analysis and chemical analysis were within 10%, and the reproducibility of activation analysis were within ±10%. (2) The relative error due to counting fluctuation was 2% for 0.01γ of manganese (2 hrs irradiation). (3) In order to eliminate the influence due to the activity of 64Cu, manganese activity should be counted from 1 to 5 hours after the irradiation for two hours.

THE INTERACTION BETWEEN DISODIUM ETHYLENEBISDITHIOCARBAMATE (NABAM) AND MANGANESE

The investigations reported in this paper show that trace amounts of manganese catalyze the oxidation of nabam. Conversion to ethylene thiuram monosulphide was found to be pH dependent. The results obtained help to explain the apparently anomalous behavior of nabam in earlier oxidation studies.

Manganese Toxicity of Potatoes in Relation to Strong Soil Acidity

A stem streak necrosis occurs quite commonly in potatoes grown on northern Wisconsin soils more acid than pH 5.0. This necrosis appears as dark brown streaks in the stem with a pale yellow chlorosis in the leaves. As the symptoms progress, the leaves dry and fall of. The affected parts are very brittle and the terminal bud becomes necrotic in severe cases. The plant dies prematurely and tuber yields are seriously reduced. Greenhouse tests with soils showed that fertilizers which lowered the pH of the soil increased the severity of the necrosis, and that it was entirely prevented by the addition of lime. Nutrient solution experiments proved that neither acidity, soluble aluminum, or a deficiency of calcium, magnesium, or iron is the cause of this necrosis, but did show that as little as 2 ppm of soluble manganese in nutrient solutions causes severe necrosis identical to that observed in potatoes in the field, while only trace amounts of manganese were found in the solutions from the same soils after they had been limed in the field. Therefore, it is concluded that an excess of soluble manganese is the soil factor which causes stem streak necrosis in potatoes grown on verymore » acid soils. The application of lime so regulated as to maintain a soil reaction of pH 5.0 to 5.3 is the most practical means of preventing this necrosis.« less