Diamine Tetraacetic Acid Disodium Salt Research Articles

Assessing Micronutrients in Soil with a New Chemical Extractant Using Isotopic Dilution Techniques: Linkages to Labile Fractions in Soil

ABSTRACT With the purpose of economizing the routine soil testing for micronutrients and avoiding the use of multiple soil extraction procedures, a laboratory investigation was attempted to evaluate a new chemical extractant for assessing the availability of common micronutrients (Fe, Cu, Mn, Zn, Mo, and B) in soils of widely varying properties (n = 32). The new extractant designated as OM-MES-VERA# contained 0.01 M oxalic acid, 0.02 M maleic acid, 0.02 M 2-(N-Morpholino) ethane sulfonic acid (MES), 0.0025 M ethylene diamine tetraacetic acid di-sodium salt, 0.02 M acetic acid, and 0.1% polyacrylamide (final pH adjusted to 6.0). OM-MES-VERA extracted significantly higher amounts of micronutrient cations and B from soils compared to the conventional diethylene triamine pentaacetic acid (DTPA, pH 7.3) extractable micronutrient cations and hot water soluble B, respectively, but lesser amount of Mo compared to Mehlich-3 universal extractant. Soil test values by both OM-MES-VERA- and conventional extractants were correlated with soil properties. The labile (E and L) values of micronutrient cations and Mo estimated by isotopic dilution method, ammonium bicarbonate-DTPA, pH 7.6 extractable soil B (as an estimate of E for B) and B concentration in maize (as an estimate of L for B) were successfully regressed on soil test values of micronutrients by OM-MES-VERA and conventional soil extractants except in the case of DTPA (pH 7.3) for E-value of Fe and L-value of Mn. The OM-MES-VERA extractant can be considered to assess the availability of common micronutrients in soils of diverse soil properties.

Extraction of Soluble Salts and Iron Sulfides from the Wood of the “Huaguangjiao I” Shipwreck

Shipwreck wood often contains soluble salts and iron sulfides, which pose a threat to its stability. Therefore, desalination treatment must be carried out during protection. In this study, deionized water and ethylene diamine tetraacetic acid disodium salt (EDTA-2Na) solution were used to extract soluble salts and iron sulfides from the 511 wood components of the “Huaguangjiao I” shipwreck. The extraction lasted for 1120 days, during which extraction progress was monitored by measuring the electrical conductivity and iron content of the soaking solution. The results indicated that the extraction experiment reached its endpoint when the conductivity of the soaking solution was maintained at 80~100 μs/cm and the iron content was maintained at 8~15 mg/L. More than 143.35 kg of iron were extracted from the wood of the “Huaguangjiao I” shipwreck. After extraction, the content of soluble salt ions in the wood were less than 5 μg/g, with an iron content below 5%. The wood has returned to its original color and with a certain degree of degradation. “Huaguangjiao I” was the first large-scale marine shipwreck to complete the desalination treatment of all wooden components. This study provides guidance for the desalination treatment of large-scale wooden shipwrecks.

Influence of wood modification with polyethylene glycol and various carboxylic acids on the dimensional stability of beech wood (Fagus sylvatica)

ABSTRACT The goal of this study was the fixation of water-soluble polyethylene glycol (PEG) into the wooden cell wall. The dimensional stability of beech wood (Fagus sylvatica) modified with PEG400 and various carboxylic acids (1,2,3,4-butanetetracarboxylic acid (BTCA), citric acid (CA), malic acid, pyromellitic acid, tartaric acid, L-glutamic acid hydrochloride, ethylene diamine tetraacetic acid disodium salt dihydrate, trans-aconitic acid, maleic acid and itaconic acid) was examined. Investigations of anti-swelling efficiency (ASE), weight-percent gain (WPG) and bulking effect were made. Both the highest dimensional stabilization (values of ASE at the end of examination between 37 and 40%) and the best fixation of the chemicals in the wood (total loss of WPG between 37 and 38%) were achieved with combinations of BTCA/PEG and CA/PEG. The variants impregnated without PEG had lower bulking values. Successful modification of wood seems to be possible with BTCA, CA and malic acid in combination with PEG400.

Purification of Extracellular Protease from Staphylococcus simulans QB7and Its Ability in Generating Antioxidant and Anti-inflammatory Peptides from Meat Proteins

Proteases, especially microbial proteases, are widely used in food processing. The purpose of this study was aimed to purify an extracellular protease produced by the strain Staphylococcus simulans QB7 and to evaluate its ability in hydrolyzing meat proteins and generating antioxidant and anti-inflammatory peptides. The optimal conditions for producing the enzyme were as follows: inoculum ratio, 10%; initial pH, 6.5; temperature, 32 °C; incubation time, 36 h; and rotation speed, 160 rpm. The protease had a molecular weight of approximately 47 kDa, possessing the optimal activity at 50 °C, pH 7.0, The protease was stable at pH 4.0-8.0 and 30-60 °C, and the activity was improved by Na+, Mg2+, Ca2+, and Zn2+ ions, whereas it was inhibited by Cu2+, Co2+, Fe3+, Ba2+, Fe2+, β-M, and ethylene diamine tetraacetic acid disodium salt (EDTA). The protease could effectively hydrolyze meat proteins, and the generated hydrolysate could significantly inhibit tumor necrosis factor-alpha (TNFα)-induced oxidative stress, including superoxide and malondialdehyde levels and inflammation (vascular adhesion molecule-1 [VCAM-1] and cyclooxygenase 2 [COX2)) in human vascular EA.hy926 cells. The present findings support the ability of S. simulans QB7 protease in generating antioxidant and anti-inflammatory peptides during the fermentation of meat products.

Unique electrochemistry of Zn electrode in Zn-EDTA aqueous solutions and its application for high-voltage Zn-MnO2 cell

• Strong chelation ability of EDTA brings about unique electrochemistry of Zn electrode in Zn-EDTA aqueous electrolyte. • Stripping potential of Zn anode in 0.1 M Zn-EDTA solution keeps unchanged with applied currents. • Nucleation over potential of Zn is much larger in 0.1 M Zn-EDTA than that in 0.1 M ZnCl 2 . • MnO 2 -Zn full cell using 0.1 M Zn-EDTA reveals 2.05 V voltage and 86.4 % capacity retention after 500 cycles. The poor reversibility of Zn anode in aqueous solution is ascribed to many parasitic reactions, such as passivation, dendrite growth, shape change, and hydrogen evolution. Here a simple strategy is reported that employs ethylene diamine tetraacetic acid disodium salt (Na 2 EDTA) as chelant to form Zn-EDTA coordination ion so as to increase the polarizability of zinc deposition, suppress dendrite generation and growth, and accordingly improve the reversibility of Zn anode. By this means, zinc anode displays good reversibility for 740 charge/discharge cycles at 8 mA cm −2 . In addition, the stripping potential of zinc anode keeps stable at −1.05 V vs SCE in the wide range of current density from 1 to 20 mA cm −2 , boosting a 2.05 V MnO 2 -Zn full cell which exhibits a discharge voltage retention rate of 83 % after 500 continuous charge/discharge cycles.

Aqueous Strippable Polymer Coating for Highly Efficient Primary Radioactive Uranium Decontamination with Versatility on Diversified Surface.

The decontamination of radioactive materials on the surfaces of nuclear facilities has generated large quantities of waste from the rapid development of the nuclear industry, posing a potential threat globally. Strippable coating has been employed for some time to remove radioactive contamination due to its high performance and removability, flexibility, and compatibility with various substrates. Herein, an aqueous strippable coating based on an adsorbent/polyvinyl alcohol (PVA) polymer was developed to remove radioactive uranium from stainless-steel surfaces that showed greater decontamination than that of DeconGel, with an efficiency of 87.2% for 5 g/L uranium and 95.5% for 22.5 g/L uranium, along with a high repeatability and better mechanical properties. Furthermore, the prepared coating was versatile and could be applied to a range of substrate surfaces (lacquered, aluminum, glass, plastic, and ceramic), with outstanding performance ranging from 79.2 to 95.4% for 1 g/L uranium. The prepared coating could also be applied through brushing or spraying to horizontal or vertical substrates. The exceptional performance could be due to the synergistic effect of the introduction of ethylene diamine tetra-acetic acid disodium salt (EDTA-2Na) as a chelating agent and the nano-adsorbent CaCO3/TiO2.

EDTA-2Na assisted facile synthesis of monoclinic bismuth vanadate (m-BiVO4) and m-BiVO4/rGO as a highly efficient visible-light-driven photocatalyst

An efficient facile synthesis method for BiVO4/reduced graphene oxide (BiVO4/rGO) photocatalyst by a one-pot hydrothermal process was first developed. Ethylene diamine tetraacetic acid disodium salt (EDTA-2Na) rather than nitrate was used to provide an acidic environment to prevent the hydrolysis of Bi3+, which could improve the safety of the process. The photocatalytic activities could be remarkably enhanced by loading BiVO4 on rGO. The degradation efficiency for Rhodamine B (rhB) could reach 98.3% in 180 min. This work offered an ideal method for stable, efficient, and recyclable photocatalysts suitable for the visible light range.

Production, purification and biochemical characterization of the microbial protease produced by Lactobacillus fermentum R6 isolated from Harbin dry sausages

This study investigated the purification and biochemical characterization of the protease produced by Lactobacillus fermentum R6 isolated from Harbin dry sausages. The optimized fermentation conditions were as follows: a fermentation time of 48 h, an initial pH of 6 and a fermentation temperature of 37 °C. The 37.7 kDa extracellular protease was purified using ammonium sulphate deposition, an ion exchange layer system and gel filtration. The protease produced by L. fermentum R6 had the highest initial velocity and kcat/Km at pH 6, 40 °C. The microbial protease activity could be inhibited by ethylene diamine tetraacetic acid disodium salt (EDTA). The Vmax and Km of the protease were 58.2 ± 1.42 mg/min and 17.3 ± 0.85 mg/mL, respectively. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) reflected the ability of the protease to hydrolyse myofibrillar and sarcoplasmic proteins, in particular, myosin heavy chain, paramyosin, phosphorylase and creatine kinase-M type. In conclusion, L. fermentum R6 can be used as a starter culture or an enzyme-producing strain for the inoculation of Harbin dry sausages.

Purification and biochemical characteristics of the protease from Lactobacillus brevis R4 isolated from Harbin dry sausages

This study investigated the purification and biochemical characteristics of the protease secreted by Lactobacillus brevis R4 that was isolated from Harbin dry sausages. The optimized fermentation conditions were a fermentation time of 36 h, an initial pH of 5 and a fermentation temperature of 42 °C. A 27.9 kDa extracellular protease was purified using ammonium sulfate precipitation, ion exchange layer and gel filtration and was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The protease produced by L. brevis R4 reached the highest relative protease activity at pH 7, 35 °C and 36 h. The microbial protease activity was inhibited by Zn2+, Cu2+ ions and ethylene diamine tetraacetic acid disodium salt (EDTA). The maximum velocity of the reaction (Vmax) and Michaelis constant (Km) of the protease were 65.9 mg/min and 17.1 mg/mL, respectively. SDS-PAGE demonstrated the ability of the protease to hydrolyse myofibrillar and sarcoplasmic proteins, especially on the myosin heavy chain, paramyosin, troponin, myosin light chain and glyceraldehyde dehydrogenase. The study provides a basis for understanding the enzymatic properties of the L. brevis R4 protease. In conclusion, L. brevis R4 has the potential to be used as a starter culture or protease-producing strain to produce Harbin dry sausages.

Purification and biochemical characteristics of the extracellular protease from Pediococcus pentosaceus isolated from Harbin dry sausages

This study investigated the purification and biochemical characteristics of the protease produced by Pediococcus pentosaceus isolated from Harbin dry sausages. The optimized fermented conditions were as follows: fermentation time 36 h, initial pH 5 and fermentation temperature 30 °C. A 29.6 kDa extracellular protease was purified using ammonium sulphate deposition, ion exchange layer system and gel filtration. The protease produced by P. pentosaceus had a certain pH and thermal stability at pH 6 and 30 °C. The microbial protease activity could be inhibited by ethylene diamine tetraacetic acid disodium salt (EDTA). Vmax and Km of the protease were 43.9 mg/min and 8.3 mg/mL, respectively. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) reflected the ability of the protease to hydrolyse sarcoplasmic and myofibrillar proteins, particularly those of myosin heavy chain, paramyosin, actin, phosphorylase and creatine kinase-M types. 3D structure modelling of the P. pentosaceus protease found two domains in the protease protein and the correlation of the active sites with protease properties and substrate specificity. In conclusion, P. pentosaceus can be used as a starter culture or enzyme producing strain for inoculation in Harbin dry sausages.

Purification and biochemical characteristics of the microbial extracellular protease from Lactobacillus curvatus isolated from Harbin dry sausages

This study investigates the purification and biochemical characteristics of the protease secreted by Lactobacillus curvatus R5, which was isolated from Harbin dry sausages. The optimized fermentation conditions were fermentation time 36 h, initial pH 6 and fermentation temperature 37 °C. An extracellular protease was purified using ammonium sulfate precipitation, ion-exchange layer and gel filtration. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed that molecular weight of the purified protease was 45.3 kDa. Protease produced by L. curvatus R5 reached a higher relative protease activity at pH 6, 40 °C, and the purified protease exhibited pH and thermal stability at pH 6 and 40 °C. The microbial protease activity can be inhibited by ethylene diamine tetraacetic acid disodium salt (EDTA). The Vmax and Km of the protease were 53 mg/min and 15.9 mg/mL, respectively. SDS-PAGE reflects the ability of the protease to hydrolyse myofibrillar protein and sarcoplasmic protein, especially on myosin heavy chain, actin, myosin light chain and phosphorylase. The 3D structure and the Ramachandran plot of L. curvatus R5 protease was obtained by homology modelling. The Ramachandran plot analysis revealed that the purified protease was composed of 366 amino acids, and its residues in favoured, allowed, generously allowed and disallowed regions were 84.6%, 11.3%, 3.2% and 0.9% residues, respectively. Molecular docking showed that the substrate actin bound to the protease active site by hydrogen bonding and hydrophobic interaction. This research provides a basis for understanding the enzymatic properties of L. curvatus R5 protease. In conclusion, L. curvatus R5 can be used as a starter culture or protease-producing strain to inoculate Harbin dry sausages.

GO/PVA nanocomposites with significantly enhanced mechanical properties through metal ion coordination

In this study, a simple and efficient way is demonstrated to create strong interfacial interaction between graphene oxide (GO) filler and poly(vinyl alcohol) (PVA) matrix through metal ion coordination. The coordination bonding provides efficient load transfer during the tensile process, and enhances the mechanical properties of the nanocomposites significantly. After being coordinated with Cu(II) ions, GO/PVA composites show much higher Young’s moduli and yield stresses than pure PVA and non-coordinated GO/PVA. UV–vis and FTIR spectra are performed to confirm the successful coordination between GO and PVA. Ethylene diamine tetraacetic acid disodium salt (EDTA-2Na) is used to confirm the important role of coordination in enhancing the composites. This research provides a new approach to manufacture polymer-matrix nanocomposites with significantly improved mechanical performances.

Simple thermal decomposition of bismuth citrate to Bi/C/α-Bi2O3 with enhanced photocatalytic performance and adsorptive ability

Exploring a simple method to prepare efficient photocatalyst is a very important technique for practical application. Herein, α-Bi2O3, β-Bi2O3 and C/Bi/α-Bi2O3 were easily obtained by calcining bismuth citrate under different conditions. Especially, C/Bi/α-Bi2O3 obtained at 450 °C in nitrogen atmosphere exhibited superior photocatalytic activity for methyl orange (MO) and malachite green (MG) degradation under visible light irradiation, higher than β-Bi2O3 and α-Bi2O3 calcined in air at 350 °C and above 450 °C, respectively. The presence of non-burned carbon in N2 atmosphere benefits to complete transformation of β-Bi2O3 into α-Bi2O3 at a annealing temperature low to 300 °C, as well as partial reduction of Bi2O3 into Bi nanoparticles. More importantly, the remaining carbon and metal Bi could enhance visible light absorption of α-Bi2O3, generate hot charge carriers and boost electron migration efficiency, which thus dramatically improve photocatalytic activity of α-Bi2O3. Furthermore, these bismuth oxides exhibit exceptionally strong adsorption ability for cationic dyes like MG and methyl violet (MV) with help of trace amount of ethylene diamine tetraacetic acid disodium salt (EDTA-2Na) and the maximum adsorption capacity for MG on α-Bi2O3 reached 312 mg/g. The as-prepared C/Bi/α-Bi2O3 also possesses good stability and recyclibility in photocatalysis and adsorption.

Cooperative Decomposition of Hydrogen Peroxide by Lignin-combined Transition Metals in Pulp Bleaching

The effects of lignin-combined manganese ion, iron ion, and lignin-combined iron and manganese on the decomposition of hydrogen peroxide were investigated. Elemental analysis and inductively coupled plasma-atomic emission spectrometry were used to analyze the chemical features of the lignin composites and the amount of metal ions present in the solution or adsorbed on lignin, respectively. The results showed that the main transition metal elements remaining in the precipitated lignin were Fe, Mn, and Cu. The hydrogen peroxide decomposition in the presence of lignin-combined transition metal was represented by pseudo-first-order kinetics, and the pseudo-first-order rate constant (kobs) of peroxide decomposition with lignin-combined iron was 0.0068 min-1, while it was 0.0063 min-1 in the presence of lignin-combined manganese. A synergistic effect of manganese and iron combined with lignin on peroxide decomposition was demonstrated, and a kobs value of 0.0053 min-1 was obtained. The mixed addition of magnesium sulfate (MgSO4), sodium silicate (Na2SiO3), and ethylene diamine tetraacetic acid disodium salt (Na2EDTA) resulted in an optimal reduction in peroxide decomposition when single lignin-combined metal ion existed. However, adding Na2EDTA alone had an optimal effect on the reduction of peroxide decomposition in the presence of lignin-combined iron and manganese, with a kobs value of 0.0004 min-1.

The morphology control of hydroxyapatite microsphere at high pH values by hydrothermal method

Hydroxyapatite (HA) microspheres were successfully synthesized under hydrothermal conditions in the presence of ethylene diamine tetraacetic acid disodium salt (Na2EDTA). The morphology and structure of the as-synthesized microspheres were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, Raman spectroscopy, and scanning electron microscopy analyses. The morphology of HA was significantly affected by pH, Na2EDTA/Ca ratio, and reaction temperature. High pH values could promote the formation of microspheres. The structures were transformed from tight to estrange with decreasing pH. The Na2EDTA/Ca ratio affected self-assembled, the ratio of Na2EDTA/Ca at 2:2 resulted in the formation of a dense spherical structure. The reaction temperature affected the degree of the density of the microspheres. HA microspheres with high crystallinity can be produced under conditions with high pH, high temperature, and moderate holding time. The mechanism underlying the formation of HA microspheres in the presence of Na2EDTA at high pH was proposed. At the initial stage of the reaction, crystals were formed and the trunk appeared with a rod-like HA self-assembly. With prolonged reaction time, dumbbell-like HA was formed. Further growth could produce HA microspheres.

Studies of Grinding Media Corrosion from Galvanic Interaction on Galena Flotation

This study has been done to determine the galvanic interaction between five types of grinding media (mild steel, cast iron, 10% chromium, 20% chromium, and ceramic media) and galena, in situ of the mill. The ceramic media has a significantly not galvanic interaction with galena and high chromium media has a significantly weaker galvanic interaction with galena, and produces a very much lower amount of oxidize iron species in the mill discharge than mild steel medium. The investigation of the various reactions occurring on the galena surface was investigated by ethylene diamine-tetra acetic acid disodium salt (EDTA) extraction and X-ray photoelectron spectroscopy (XPS) measurements. The floatability of galena is dependent on the galvanic current between grinding media and galena during grinding because the current is relative to the amount of iron oxidation species and the reduction rate on galena. Iron oxidation species depressed galena flotation. The optimum galena flotation was achieved by selecting grinding conditions that enabled iron oxidation to be controlled.

Facile synthesis of antimony selenide with lamellar nanostructures and their efficient catalysis for the hydrogenation of p-nitrophenol

Abstract Antimony selenide (Sb2Se3) composed of numerous lamellas with average thickness of circa (ca.) 10 nm have been fabricated through a hydrothermal method, in which ethylene diamine tetraacetic acid disodium salt (Na2EDTA) is selected as complex agent. Experimental parameters such as concentration of reactants and alkaline condition play crucial roles in determining the morphologies and homogeneity of the final products. Interesting self-assemble process and color change in stock solution has been observed, and a possible growth mechanism of Sb2Se3 with distinctive morphologies is proposed and discussed in detail. Importantly, the as-prepared products show efficient catalytic performance for reduction of p-nitrophenol to p-aminophenol at room temperature.

Purification of diamine oxidase and its properties in germinated fava bean (Vicia faba L.)

γ-Aminobutyric acid (GABA) is a non-protein amino acid with bioactive functions for human health. Diamine oxidase (DAO, EC 1.4.3.6) is one of the key enzymes for GABA formation. In the present study, this enzyme was purified from 5 day germinated fava bean and its properties were investigated in vitro. The molecular mass of the enzyme estimated by Sephadex G-100 gel filtration was 121 kDa. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) displayed a single band at a molecular mass of 52 kDa. The enzyme had optimal activity at 40 °C and retained its activity after being incubated at 30 °C for 30 min. It showed higher activity at pH 6.5 than at other pH values. The enzyme was significantly inhibited by Mg(2+), Cu(2+), Fe(3+), aminoguanidine, ethylene glycol tetraacetic acid (EGTA), ethylene diamine tetraacetic acid disodium salt (EDTA-Na(2)), L-cysteine and β-mercaptoethanol. The K(m) value of DAO was 0.23 mmol L(-1) for putrescine and 0.96 mmol L(-1) for spermidine. However, the enzyme did not degrade spermine. DAO from germinated fava bean was purified. The optimal reaction temperature and pH of the enzyme were mild. The enzyme had higher affinity to putrescine than to spermidine and spermine.

电化学刻蚀制备的荧光碳纳米颗粒

The fluorescent carbon nanoparticles were synthesized by electrochemistry etching graphite electrode using the ethylene diamine tetraacetic acid disodium salt solution as the electrolyte.The properties of the light absorption and fluorescence emission of carbon nanoparticles were obtained by electrochemistry etching and were characterized by UV-Vis absorption and fluorescence spectrophotometers.The crystal characterizations and compositions of the obtained carbon nanoparticles were investigated by employing the transmission electron microscope and energy disperse spectroscopy.The results show that carbon nanoparticles with several nanometers are dispersive and exhibit the strong absorption at 325 nm and the bright blue light emission.The effects of the electrolytic solutions and concentrations on the light emissions from carbon nanoparticles were also studied.Finally,the origin of the light emission from carbon nanoparticles obtained by electrochemistry etching was proposed.

Hydrothermal Synthesis of Hydroxyapatite Urchins and its Drug Release Property

Hydroxyapatite (HAP) urchins were synthesized by a facile hydrothermal method using calcium nitrate, ammonium dihydrogen phosphate, diamine tetraacetic acid disodium salt as complexing agent and ethonalamine as alkaline source. The influence of hydrothermal time on crystallinity and morphology of HAP have been investigated. The results indicate that well-crystallized HAP urchins can be synthesized at 180°C for 24h. SEM images show a large area of urchin-like microspheres consisted of a number of ribbons with lengths ranging from 2 to 5μm. Based on XRD and SEM results, the formation mechanism of HAP crystals has been discussed. A typical anti-inflammatory drug, ibuprofen, was used for drug loading, and the release behaviors of ibuprofen in a simulated body fluid (SBF) were studied. The results indicate that HAP urchins showed a favorable sustained release property for ibuprofen.