Addition Of Ethylenediaminetetraacetic Acid Research Articles

Effect of EDTA on measurement of cortisol and thyroxine by chemiluminescent enzyme immunoassay in dogs.

The addition of ethylenediamine tetra-acetic acid (EDTA) to serum can affect the measurement of cortisol by chemiluminescent enzyme immunoassay (CEIA); addition of magnesium chloride (MgCl2) may reverse the effects. However, similar characteristics for thyroxine (T4) measurement are unknown. We measured cortisol and T4 in paired EDTA-anticoagulated plasma and serum samples from 50 dogs. Additionally, both hormones were measured in 15 samples of each type after the addition of MgCl2. Samples were collected under routine clinical conditions; therefore, specific EDTA concentrations in plasma samples were unknown. Cortisol and T4 values were significantly different comparing plasma and serum samples in the absence of MgCl2. For cortisol and T4, EDTA-plasma concentrations were 51.2% and 43.7% higher than serum, respectively (p < 0.001 for both). The addition of MgCl2 to plasma significantly decreased the measured cortisol concentrations (p < 0.001) but not T4 (p = 0.44). After addition of MgCl2, cortisol concentrations in EDTA-plasma were no longer significantly different from serum, whereas T4 concentrations in EDTA-plasma remained significantly different from serum. In the clinical setting in which tubes may be underfilled, use of EDTA-plasma significantly increases the measured concentration of cortisol and T4 obtained by CEIA. Addition of MgCl2 to EDTA-plasma can overcome the effects of EDTA when measuring cortisol, but not T4. Thus, T4 should not be measured in EDTA-plasma.

The value of EDTA treatment of hatchery water to rear Greenshell™ mussel (Perna canaliculus) larvae

The chelating agent ethylenediaminetetraacetic acid (EDTA) is used throughout the world to improve the yield of early stage D-larvae during bivalve hatchery production. Adding EDTA (12 μM) to seawater significantly increases the survival of Greenshell™ mussel (Perna canaliculus) larvae during their first 48 h of development. However, whether there are benefits of continuing to use EDTA beyond this first stage of larval development remain unknown and were tested in this study. After rearing for 48 h in the presence of EDTA, P. canaliculus larvae were experimentally raised to 22-day post-fertilisation in seawater with and without 12 μM EDTA. The survival, shell length growth, algal ingestion rate, swimming activity and potential toxic metal accumulation by the larvae were compared over this period. There were minimal benefits from continuing addition of EDTA. However, significant changes in metal concentrations within the larvae were observed. Zinc, cadmium and mercury were detected at significantly lower concentrations in 22-day-old larvae reared with EDTA versus those without EDTA. Collectively, the results indicate that the use of EDTA is critical only during the first 48 h of larval development, during which time larval shell formation is initiated and appears highly vulnerable to interference by heavy metal ions.

Shape-controlled microwave hydrothermal synthesis of antiferromagnetic GdVO4 nanowires for magnetocaloric materials

GdVO4 nanowires have been fabricated by a microwave-assisted hydrothermal method with the addition of EDTA (ethylenediaminetetraacetic acid) during synthesis. The GdVO4 nanowires have a lower antiferromagnetic (AFM) ordering temperature (TN) and effective magnetic moment μeff than them of bulk GdVO4. In a field-cooled mode, upward magnetization was found below TN in the magnetization-temperature measurements because of surface effects, where uncompensated surface spins were not ordered as AFM states. With a magnetic field change of 5 T, the maximum value of magnetic entropy change (−ΔSMmax) is 35.77 J kg−1 K−1 at 2.3 K and the relative cooling power is 211.04 J kg−1 with no hysteresis loss. The nanocrystalline GdVO4 nanowires produce a significant reversible magnetocaloric effect (MCE) and can be applied to hydrogen liquefaction as a cryogenic MCE material.

Quality of Garut Ram’s Sperm in Tris Extender Supplemented with Ethylene Diamine Tetraacetic Acid Preserved at Low Temperature (3–5°C)

Ethylenediaminetetraacetic acid (EDTA) is a chemical substance that can bind the heavy metal and other toxic compounds so it is suitable to use for protecting sperm during preservation at 3-5°C. The research aimed to evaluate the role of EDTA to maintain the quality of Garut ram sperm in low-temperature preservation. Semen was collected by an artificial vagina. Fresh semen was evaluated and divided into 3 tubes and diluted with tris extender contain 20% egg yolk (TEY) without EDTA (T1), TEY+0.01% EDTA (T2) and TEY+0.02% EDTA (T 3). Semen was evaluated both macroscopically and microscopically before preserved in a refrigerator at 3-5°C. During storage, semen was also evaluated on daily basis (four consecutive days) that included variables relate to sperm motility (SM), sperm viability (SV), sperm membrane integrity (SMI) and sperm acrosome intact (SAI). The research design used was Completely Randomized Design with three treatments and five replications. Differences between treatments were tested with the least significant difference test. The results showed that the average of each variable gained of fresh semen was 0.88mL for volume, cream for color, thick for consistency and 7 for pH. While the mass movement of sperm was +++ and sperm concentration was 3,962 million cells/mL. The average percentages of SM, SV, abnormality, SMI, and SAI were 75.00%, 86.60%, 4.80%, 84.40%, and 84.80%, respectively. On the day-4 of storage, percentages of SM, SV, SMI, and SAI in control (T1) decreased to 48.75%, 66.25%, 64.75%, and 63.5%, respectively, but still met the requirement of sperm quality for artificial insemination purposes. Moreover, there was no significant difference between T2 (45.00%, 65.00%, 63.25% and 65.25%) and T3 (40.00%, 65.67%, 60.75% and 62.50%) of those variables measured. Finally, it was concluded that the addition of EDTA in Tris extender could maintain the quality of Garut ram sperm.

Improvement effect of organic ligands on chalcopyrite leaching in the aqueous medium of sulfuric acid‑hydrogen peroxide-ethylene glycol

The addition of ethylenediaminetetraacetic acid (EDTA) to a 1 M H2O2 leaching solution with low concentrations of sulfuric acid (0.007 M) and ethylene glycol (EG) (0.1 M) promotes significant increases of copper and iron leached from chalcopyrite. However, copper purification by solvent extraction is not possible due to the elevated stability of copper-EDTA and iron-EDTA complexes in the resulting leach liquor. Therefore, a two-stage process is presented that enables copper and iron dissolution at ambient temperature and pressure (26 °C and 101.325 kPa, respectively), without the necessity of solvent extraction. The proposed process uses the H2SO4-H2O2-ethylene glycol leaching solution in combination with organic ligands (oxalic acid (OxA) or EDTA). The first stage, using the leaching solution with oxalic acid, dissolved 29.5% of iron and transformed 49% of the copper to an oxalate salt; while in the second stage, the H2SO4-H2O2-ethylene glycol-EDTA leaching solution favored both the rapid dissolution of the copper oxalate salt and the chalcopyrite that did not react in the first stage. In this manner, the pregnant leach solution (PLS) from the second stage contained 90% and 35% of the total copper and iron, respectively, which may be electrowon directly. These results showed that the use of organic ligands promotes the formation of copper and iron complexes which help to delay, but not to avoid the decomposition of hydrogen peroxide due to a Fenton reaction and therefore, this results in an increase of the percentages of copper and iron leached, which permits processing at higher pulp density (50 g/L).

Leaching Potential of Multi-metal-Contaminated Soil in Chelate-Aided Remediation

Chelates, used to increase the uptake of heavy metals in phytoremediation, can also increase the mobility of metals. If plants fail to uptake or stabilize all the mobilized metals, then subsurface soil or groundwater can be contaminated. Therefore, the type and concentration of chelate used and proper site management are important for chelate-aided phytoremediation. In this study, we evaluated potential metal leaching from the soil after applying three different chelates. The readily soluble and exchangeable metal (RSEM) and plant-available metal (PAM) of Pb, Zn, Cu, Cd, and Ni in soil amended with ethylene diamine tetra acetic acid (EDTA), ethylene diamine disuccinate (EDDS), or humic acid (HA) were analyzed, and the potential leaching factor (PLF) of the heavy metals was estimated. Results showed that the effects of chelates and their concentration on RSEM and PAM of heavy metal in soil were different. The addition of EDTA increased the CRSEM and CPAM of all heavy metals, although its effects varied with the concentration added. EDDS application increased CRSEM and CPAM of Cu, Ni, and Zn, but EDDS was more effective than EDTA for Cu and Ni. HA did not show a significant impact due to the short duration of the experiment. In most cases with chelates effects, the increase of RSEM was greater than PAM, and the potential of metal leaching increased. Therefore, application of chelates for remediation of metal-contaminated soil should consider not only the capacity of metal uptake in plants but also the potential metal leaching from the system. Additionally, this process should be accompanied by proper water management to minimize leachate in chelate-aided phytoremediation applications.

Examining the role of ethylenediaminetetraacetic acid (EDTA) in larval shellfish production in seawater contaminated with heavy metals

Heavy metal pollution is a concern in many coastal locations where it is frequently deleterious to the survival of young shellfish. Consequently, a great number of commercial shellfish hatcheries around the world rely on the addition of ethylenediaminetetraacetic acid (EDTA) to seawater to ensure successful larval production. Despite the importance of this practice to global shellfish production the mode of action of EDTA in larval production remains undetermined. It is assumed EDTA chelates heavy metals in seawater preventing interference in larval development. Larval mussels (Perna canaliculus) raised in seawater with 3 μM EDTA had a 15 fold higher yield than those without EDTA. The concentration and spatial arrangement of heavy metals in larvae as determined by Inductively Coupled Plasma Mass Spectrometry (ICPMS) and X-ray Fluorescence Microscopy (XFM) was consistent with reduced bioavailability of several metals, especially copper and zinc. This is the first study to confirm the effectiveness of EDTA for managing metal pollution commonly encountered in coastal shellfish hatcheries.

Enhancing the antimicrobial properties of borates in coolant fluids

Studied the effects of C10H16O8N2 ethylenediaminetetraacetic acid (EDTA) and its C10H14O8N2Na2 disodium salt (trilon B) on the antimicrobial properties of lithium monoborate (LiBO2), sodium (NaBO2) and potassium (KBO2) in 3% emulsion coolant «Ukrinol-1». Established that the listed monoborates have antimicrobial properties in 3% emulsion coolant «Ukrinol-1». The addition of EDTA and trilon B separately at concentration of 1 g/l, enhances almost 2 times the antimicrobial activity of monoborates in the coolant emulsion. Thus, the addition of 30 g/l of sodium monoborate in combination with 1 g/l of EDTA increases the service life of 3% emulsion of «Ukrinol-1» coolant fluid up to 87 days. In combination with trilon B the term of the antimicrobial action of borates in 3% emulsion of the coolant «Ukrinol-1» increases to greater extent than in the presence of EDTA and its service life increases up to 110 days. All this allows us to recommend the studied composition as the antimicrobial additive to improve the sanitary and hygienic working conditions of machine workers and increasing the service life of the 3% emulsion coolant «Ukrinol-1» used for machining of metals.

Enhanced photocatalytic reduction of toxic Cr(VI) with Cu modified ZnO nanoparticles in presence of EDTA under UV illumination

In this study, the photocatalytic reduction of Cr(VI) to Cr(III) in aqueous solution using 1 wt% Cu/ZnO photocatalyst in presence of ethylenediaminetetraacetic acid (EDTA) under UV irradiation was investigated. The photocatalytic Cr(VI) reduction with ZnO under UV irradiation was significantly low. A fast Cr(VI) reduction with ZnO was recorded in presence of EDTA. Results demonstrated that the rate constant raised from 1.6 × 10−2 to 7.5 × 10−2 min−1 with 20 ppm EDTA addition. The optimum reduction (90%) was observed within 30 min at pH 3. The reduction efficiency of Cr(VI) was evidently increased from 6% to 99%, with increasing ZnO dosages up to 40 mg. The role of co-catalysts such as Au, Ag, Cu and NiO was also studied. The addition of Cu ion remarkably accelerated the reduction of Cr(VI), compared with ZnO/EDTA system alone. The Cu motivated ZnO/EDTA system completed the 99% reduction within only 30 min. The Cu ions were reduced to metallic copper and Cu2O by conduction band electrons of ZnO. The electron–hole recombination was gently declined by the shallow electron trapping of Cu. On the other hand, EDTA could be performed in two ways by forming Cr(III)-complex and separating Cr(III) from ZnO surface and by consuming valence band holes. The Cu modified ZnO photocatalyst was characterized by N2 adsorption- desorption isotherm, TEM, EDX, XPS, DRS and PL spectra. We evaluated the influence of pH, photocatalyst dosage, initial concentration of EDTA and initial concentration of Cu2+ ion (Cu doping amount) on photocatalytic reduction of Cr(VI). The pseudo first order kinetic reaction was confirmed for this reduction process. Herein, a probable mechanism of this photocatalytic reduction process was also presented.

The effect of Cu-resistant plant growth-promoting rhizobacteria and EDTA on phytoremediation efficiency of plants in a Cu-contaminated soil.

Remediation of heavy metal-contaminated soils is essential for safe agricultural or urban land use, and phytoremediation is among the most effective methods. The success of phytoremediation relies on the size of the plant biomass and bioavailability of the metal for plant uptake. This research was carried out to determine the effect of Ethylenediaminetetraacetic acid (EDTA) ligand and Cu-resistant plant growth-promoting rhizobacteria (PGPR) on phytoremediation efficiency of selected plants as well as fractionation and bioavailability of copper (Cu) in a contaminated soil. The test conditions included three plant species (maize: Zea mays L., sunflower: Helianthus annuus L., and pumpkin: Cucurbita pepo L.) and six treatments, comprising two PGPR strains (Pseudomonas cedrina K4 and Stenotrophomonas sp. A22), two PGPR strains with EDTA, EDTA, and control (without PGPR and EDTA). The combination of EDTA and PGPR enhanced the Cu concentration in both shoot and root tissues and increased the plant biomass. The Cu specific uptake was at a maximum level in the shoots of pumpkin plants when treated with the PGPR strain K4 + EDTA (202μgpot-1), and the minimum amount of Cu was recorded for sunflower with no PGPR or EDTA addition (29.6μgpot-1). The result of the PGPR-EDTA treatments showed that the combined application of EDTA and PGPR increased the shoot Cu-specific uptake approximately fourfold in pumpkin. Pumpkin with the highest shoot Cu specific uptake and maize with the highest root Cu specific uptake were the most effective plants in phytoextraction and phytostabilization, respectively. The effectiveness of different PGPR-EDTA treatments in increasing Cu specific uptake by crop plants was assessed by measuring the amount of Cu extracted from the rhizosphere soil adhering to the roots of crop species, by the use of the single extractants Diethylenetriamine pentaacetic acid (DTPA), H2O, NH4NO3, and NH4OAc. PGPR-EDTA treatments increased the amount of water-extractable Cu from rhizosphere soils more than ten times that of the control. The combined application of the EDTA and PGPR reduced the carbonated Fe and Mn oxide-bound Cu in the contaminated soil, and increased the soluble and exchangeable concentration of Cu. Pumpkin, with high shoot biomass and the highest shoot Cu specific uptake was found to be the most effective field crop in phytoextraction of Cu from the contaminated soil. The results of this pot study demonstrated that the EDTA+PGPR treatment could play an important role in increasing the Cu bioavailability and specific uptake by plants, and thus increasing the phytoremediation efficiency of plants in Cu-contaminated areas.

Synthetic Effect of EDTA and Ni2+ on Methane Production and Microbial Communities in Anaerobic Digestion Process of Kitchen Wastes

Batch tests were carried out to study the effect of simultaneous addition of ethylenediaminetetraacetic acid and Ni2+ (EDTA-Ni) on anaerobic digestion (AD) performances of kitchen wastes (KWs). The results indicated that the cumulative biogas yield and methane content were enhanced to 563.82 mL/gVS and 63.7% by adding EDTA-Ni, respectively, which were almost 1.15 and 1.07-fold of that in the R2 with Ni2+ addition alone. At the same time, an obvious decrease of propionic acid was observed after EDTA-Ni addition. The speciation analysis of Ni showed that the percentages of water-soluble and exchangeable Ni were increased to 38.8% and 36.3% due to EDTA-Ni addition, respectively. Also, the high-throughput sequencing analysis revealed that the EDTA-Ni promoted the growth and metabolism of Methanosarcina and Methanobacterium, which might be the major reason for propionic acid degradation and methane production.

Influence of metal ions on glyphosate detection by FMOC-Cl.

Glyphosate (GLP, N-(phosphonomethyl)glycine) is the most important broadband herbicide in the world, but discussions are controversial regarding its environmental behaviour and distribution. Residue analyses in a variety of environmental samples are commonly conducted by HPLC-MS where GLP needs to be derivatised with 9-fluoromethoxycarnonyl chloride (FMOC-Cl). Since this derivatisation reaction was suspected to be inhibited by metal ions in the sample matrix, the present study provides a comprehensive experimental study of the effect of metal ions (Al3+, Ca2+, Cd2+, Co2+, Cu2+, Fe2+, Fe3+, Mg2+, Mn2+, Zn2+) on derivatisation and GLP recovery. Results show that some metals (Cd2+, Co2+, Cu2+, Mn2+ and Zn2+) decreased the GLP recovery down to 19 to 59%. Complementary, quantum chemical modelling of 1:1 GLP-metal complexes as well as their reactivity with respect to FMOC-Cl was performed. Here, a decrease in reactivity of FMOC-Cl towards GLP-metal complexes is observed; i.e. the reaction is non-spontaneous in contrast to the free GLP case. The present results are in accord with previous studies and provide an explanation that full GLP recovery in different matrices was never reached. Remedy strategies to compensate for the inhibition effect are explored such as pH adjustment to acidic or alkaline conditions or addition of ethylenediaminetetraacetic acid (EDTA). In general, our results question the use of internal isotopic labelled standards (ILS) since this presupposes the presence of the analyte and the ILS in the same (free) form.

Effect of ligands on the production of oxidants from oxygenation of reduced Fe-bearing clay mineral nontronite

Abstract Oxygenation of reduced iron-bearing clay minerals produces highly reactive oxidants that are capable of transforming a range of organic compounds, which is of great environmental importance, but the effect of Fe-chelating ligands on this process has not been studied. In this work, oxidant production from oxygenation of reduced nontronite was investigated in the presence of four common ligands. Addition of phosphate, tripolyphosphate (TPP), nitrilotriacetic acid (NTA) and ethylene diaminetetraacetic acid (EDTA) all significantly increased the oxidant yields, but the specific mechanisms varied, depending on the ligand types. NTA and EDTA addition promoted dissolution of structural Fe, forming aqueous NTA-Fe2+ and EDTA-Fe2+ complexes. Upon exposure to air, these complexed species rapidly oxidized through homogeneous Fenton reaction, forming chelated soluble Fe3+ species, which were rapidly reduced back to Fe2+ by electrons transferred from structural Fe(II) in reduced nontronite. With increasing NTA and EDTA loadings, homogeneous Fenton reaction gradually dominated over heterogeneous oxidation of structural Fe(II). Because of rapid air oxidation of NTA-Fe2+ and EDTA-Fe2+ complexes, these species were maintained at low levels in aqueous solution, thus minimizing the quenching effect of oxidants by excess Fe2+and the probability of non-oxidant generation pathway, both of which contributed to the observed increase of the oxidant yields. In contrast, phosphate increased the oxidant yield through sorption to the surface of reduced NAu-2 and a subsequent shift of weak oxidant [possibly Fe(IV)] to strongly reactive hydroxyl radicals (HO ). TPP played a dual role by both changing the surface catalytic properties of nontronite through sorption and enhancing homogeneous Fenton reaction by chelating with aqueous Fe2+ and Fe3+. These results shed lights on how commonly present natural and synthetic ligands affect the oxidation process of reduced iron-bearing clay minerals and oxidant production, hence providing a theoretical basis for understanding oxidant-promoted transformation mechanisms of organic matter in either natural or engineered systems.

Ecotoxicological responses of the earthworm Eisenia fetida to EDTA addition under turfgrass growing conditions

As a commonly used chelator, ethylenediaminetetraacetic acid (EDTA) enters soil environment inevitably and has the potential to cause negative effects on soil organisms. The objective of the current study was to investigate the effects of EDTA on earthworm growth, survival and activities of antioxidant enzymes. The assessment for EDTA toxicity toward earthworms (Eisenia fetida) was conducted on day 14 and 35 after exposure to four concentrations (0, 5, 10, 15 mmol kg−1) of EDTA under turfgrass growing conditions. Exposure to EDTA resulted in a significant decrease of earthworm growth and survival. The toxicity of EDTA increased with the increase in concentration and exposure duration. The activities of antioxidant enzymes increased at low concentration and decreased at high concentration, which indicates that oxidative stress was induced by EDTA addition. These results suggest EDTA is highly toxic and ecologically dangerous to earthworms.

Synergistic Effect of Combinations Containing EDTA and the Antimicrobial Peptide AA230, an Arenicin-3 Derivative, on Gram-Negative Bacteria.

The worldwide occurrence of resistance to standard antibiotics and lack of new antibacterial drugs demand new strategies to treat complicated infections. Hence, the aim of this study was to examine the antibacterial activities of an antimicrobial peptide, arenicin-3 derivative AA230, and ethylenediaminetetraacetic acid (EDTA) as well as the two compounds in combination against Gram-negative bacteria. AA230 showed strong antibacterial activity against all of the studied standard strains and clinical isolates, with minimum inhibitory concentrations ranging between 1 µg/mL and 8 µg/mL. AA230 exhibited a bactericidal mode of action. EDTA inhibited the growth of Acinetobacter baumannii at 500–1000 µg/mL. Strains of Acinetobacter baumannii were found to be more susceptible to EDTA than Pseudomonas aeruginosa or Escherichia coli. The antibacterial effects of both AA230 and EDTA were independent of the antibiotic resistance patterns. Indifference to synergistic activity was observed for AA230 and EDTA combinations using checkerboard titration. In time-kill studies, a substantial synergistic interaction between AA230 and EDTA was detected against all of the tested strains. The addition of EDTA enabled a 2–4-fold decrease in the AA230 dose. In conclusion, AA230 could have potential applications in the treatment of infections caused by Gram-negative organisms, and its effect can be potentiated by EDTA.

A protocol for urine collection and storage prior to DNA methylation analysis.

BackgroundUrine poses an attractive non-invasive means for obtaining liquid biopsies for oncological diagnostics. Especially molecular analysis on urinary DNA is a rapid growing field. However, optimal and practical storage conditions that result in preservation of urinary DNA, and in particular hypermethylated DNA (hmDNA), are yet to be determined.AimTo determine the most optimal and practical conditions for urine storage that result in adequate preservation of DNA for hmDNA analysis.MethodsDNA yield for use in methylation analysis was determined by quantitative methylation specific PCR (qMSP) targeting the ACTB and RASSF1A genes on bisulfite modified DNA. First, DNA yield (ACTB qMSP) was determined in a pilot study on urine samples of healthy volunteers using two preservatives (Ethylenediaminetetraacetic acid (EDTA) and Urine Conditioning Buffer, Zymo Research) at four different temperatures (room temperature (RT), 4°C, -20°C, -80°C) for four time periods (1, 2, 7, 28 days). Next, hmDNA levels (RASSF1A qMSP) in stored urine samples of patients suffering from bladder cancer (n = 10) or non-small cell lung cancer (NSCLC; n = 10) were measured at day 0 and 7 upon storage with and without the addition of 40mM EDTA and/or 20 μl/ml Penicillin Streptomycin (PenStrep) at RT and 4°C.ResultsIn the pilot study, DNA for methylation analysis was only maintained at RT upon addition of preserving agents. In urine stored at 4°C for a period of 7 days or more, the addition of either preserving agent yielded a slightly better preservation of DNA. When urine was stored at -20 °C or -80 °C for up to 28 days, DNA was retained irrespective of the addition of preserving agents. In bladder cancer and NSCLC samples stored at RT loss of DNA was significantly less if EDTA was added compared to no preserving agents (p<0.001). Addition of PenStrep did not affect DNA preservation (p>0.99). Upon storage at 4°C, no difference in DNA preservation was found after the addition of preserving agents (p = 0.18). The preservation of methylated DNA (RASSF1A) was strongly correlated to that of unmethylated DNA (ACTB) in most cases, except when PCR values became inaccurate.ConclusionsAddition of EDTA offers an inexpensive preserving agent for urine storage at RT up to seven days allowing for reliable hmDNA analysis. To avoid bacterial overgrowth PenStrep can be added without negatively affecting DNA preservation.

Chelating agents in aqueous, partially-hydrolyzed, poly(vinyl acetate) dispersions crosslinked with borax. Physicochemical characterization and an application

The physico-chemical properties of two chelating agents, trisodium citrate (TSC) and ethylenediamine tetraacetic acid (EDTA), have been studied in highly viscous polymeric dispersions (HVPDs), obtained by crosslinking partially hydrolyzed (ca. 80 or 87% with 3% of the monomer units with carboxylate groups) poly(vinyl acetate)s (xPVA, where × = 80 or 87, respectively) with borax in water. Small angle X-ray scattering (SAXS), 11B NMR and rheology data for the systems are reported as a function of the concentration of the chelators. The SAXS data show that addition of TSC or EDTA increases the dimensions of the xPVA-based network as well as the affinity between the polymer chains and the aqueous continuous phase. 11B NMR spectra indicate that less than 15% of the borate ions were esterified by the hydroxyl groups of the xPVA and that the degree of boron crosslinking was not affected significantly by the addition of TSC or EDTA. Oscillating rheological tests, conducted in the linear viscoelastic region, show that both these chelators have a structuring effect on the 80PVA and 87PVA crosslinked networks. Furthermore, calculated continuous mechanical relaxation spectra H(τ) show the presence of a single peak whose width increases upon increasing the concentration of either of the chelators, indicating a broadening of the distribution of the relaxation modes. In addition, the structural effects of the addition of metal ions into the HVPDs were investigated by means of SAXS and 11B NMR. Finally, the efficiency of the HVPDs for the removal of surface degradation patinas on an artificially prepared copper specimen and on a XIII century reliquary box was tested. The amount of altered copper removed from the copper plates was assessed by ICP analyses.

Improvement of the phytoremediation efficiency of Neyraudia reynaudiana for lead-zinc mine-contaminated soil under the interactive effect of earthworms and EDTA

Slow plant growth, low biomass, and low bioavailability of heavy metals in soil are important factors that limit remediation efficiencies. This study adopted a pot cultivation method to evaluate the phytoremediation efficiency of Neyraudia reynaudiana, planted in contaminated soil from a lead-zinc mining area. The soil was inoculated with earthworms (Eisenia fetida), and mixed with the chelating agent ethylenediaminetetraacetic acid (EDTA) one month after planting. The addition of earthworms significantly increased the aboveground biomass of N. reynaudiana and activated heavy metals in the soil, thus facilitating heavy metal uptake by N. reynaudiana. The addition of EDTA significantly increased the incorporation and transport of heavy metals, reduced the uptake of heavy metals by the plant cell wall, and increased the proportions of cellular soluble constituents. Especially with regard to lead, inoculation with earthworms and EDTA application significantly promoted the accumulation efficiency of N. reynaudiana, increasing it 7.1-16.9-fold compared to the control treatment without earthworms and EDTA, and 1.5-2.3-fold compared to a treatment that only used EDTA.

Preparation of complexant-modified Cu/ZnO/Al2O3 catalysts via hydrotalcite-like precursors and its highly efficient application in direct synthesis of isobutanol and ethanol from syngas

The Cu/ZnO/Al2O3 catalysts (CuZnAl) can be utilized to directly synthesize isobutanol from syngas at low temperatures, and complexants are new and efficient modifiers for the catalysts used to synthesize higher alcohols. However, little is known about effects of the complexants such as ethylene diamine tetra-acetic acid (EDTA) and triethanolamine (TEA) on structure and catalytic activity of CuZnAl. In this work, the precursors of CuZnAl, hydrotalcite-like compounds (HTLCs), were treated with EDTA and TEA to obtain the CuZnAl modified by EDTA (CuZnAl-EDTA) and TEA (CuZnAl-TEA). The catalytic performances of CuZnAl, CuZnAl-EDTA and CuZnAl-TEA were evaluated. Addition of EDTA or TEA increased CO conversion and selectivity for isobutanol and ethanol compared with pure CuZnAl. All the samples were characterized by BET, XRD, SEM, CO–TPD, CO2–TPD, H2–TPR and FTIR spectroscopy to further disclose the reason for better catalytic performance of CuZnAl-EDTA and CuZnAl-TEA. We found that the EDTA and TEA promote reduction of CuO, increase in concentration of basic sites and formation of floccule-like structure, which efficiently improves catalytic activity of CuZnAl-EDTA and CuZnAl-TEA for synthesis of isobutanol and ethanol. However, EDTA restrains CO desorption from the surface of the catalysts, and thus the strongly adsorbed CO molecules may lead to lower catalytic activity of CuZnAl-EDTA compared with CuZnAl-TEA.

Microbial Degradation of Amino Acid-Containing Compounds Using the Microcystin-Degrading Bacterial Strain B-9.

Strain B-9, which has a 99% similarity to Sphingosinicella microcystinivorans strain Y2, is a Gram-negative bacterium with potential for use in the degradation of microcystin-related compounds and nodularin. We attempted to extend the application area of strain B-9 and applied it to mycotoxins produced by fungi. Among the tested mycotoxins, only ochratoxin A was completely hydrolyzed to provide the constituents ochratoxin α and l-phenylalanine, and levels of fumonisin B1 gradually decreased after 96 h. However, although drugs including antibiotics released into the aquatic environment were applied for microbial degradation using strain B-9, no degradation occurred. These results suggest that strain B-9 can only degrade amino acid-containing compounds. As expected, the tested compounds with amide and ester bonds, such as 3,4-dimethyl hippuric acid and 4-benzyl aspartate, were readily hydrolyzed by strain B-9, although the sulfonamides remained unchanged. The ester compounds were characteristically and rapidly hydrolyzed as soon as they came into contact with strain B-9. Furthermore, the degradation of amide and ester compounds with amino acids was not inhibited by the addition of ethylenediaminetetraacetic acid (EDTA), indicating that the responsible enzyme was not MlrC. These results suggest that strain B-9 possesses an additional hydrolytic enzyme that should be designated as MlrE, as well as an esterase.