Zinc Enrichment Research Articles

Application of dual cloud point extraction for the enrichment of zinc in serum samples of psychiatric patients prior to analysis by FAAS

It is reported in literature that zinc (Zn2+) has antidepressant activity. In present study Zn2+ was analyzed in blood serum of male patients having various psychiatric disorders (schizophrenia, depression, bipolar). As it is usually present in trace levels. Hence a novel, environmental friendly, dual-cloud point extraction (d-CPE) method was developed for the enrichment of its trace levels in acid digested serum samples. In the first step of d-CPE, Zn2+ was complexed with 1-(2-pyridylazo)-2-naphthol (PAN), and the complex was entrapped in a nonionic surfactant (Triton X-114). After achieving cloud point by heating, the mixture was separated into two layers i.e. aqueous and surfactant-rich by centrifugation. In second step of d-CPE, the analyte complex in the surfactant-rich phase was treated wih acid to extract back the metal analytes in acidic aqueous phase, the mixture was again heated upto cloud point and the whole procedure was repeated. This time the aqueous phase, having the metals, was taken and subjected to FAAS using conventional nebulization. The accuracy of the developed methodologies (conventional and d-CPE), were verified by their application to certified reference material of serum (CRM). Reliability of the method was checked by relative standard deviation (%RSD), which was found to be <5%. The limit of detection and limit of quantification were calculated for the proposed method as 1.09μg/L, and 3.63 respectively and enhancement factor was found to be 40. The developed procedure was successfully applied to the serum samples of patients (male) having different psychiatric disorders and non-psychiatric control subjects for the determination of Zn2+.

Zinc solubilizing Bacillus strains that modulate growth, yield and zinc biofortification of soybean and wheat

Zinc (Zn), an essential micronutrient, is required for improving crop productivity, human and animal nutrition. To overcome zinc deficiency, use of zinc solubilizing bacteria has been a promising alternative for enhancing zinc availability in soil and thereby improving zinc assimilation in seeds while maintaining crop yield. The premise of this study is to isolate and identify predominant Bacillus isolates from Nimar region and their effect on yield enhancement, zinc -mobilization and -assimilation by soybean and wheat crops. In this study, we recovered a total of 115 predominant bacilli from rhizosphere of two soybean cultivars namely JS 93-05 and JS 335 cultivated at 17 different locations of Nimar region, Madhya Pradesh, India. Of the 115 isolates, 20 potential zinc solubilizing bacilli were selected. Isolates KMR-5, THB-2, BBU-5, DBU-5, DBU-1, KHKD-1, KKI-6 and BHKD-6 were found to be highly efficient in solubilizing insoluble zinc compounds both on solid plate and in liquid assay conditions. Twenty bacilli were identified as Bacillus cereus, B. anthracis, B. thuringiensis, B. tequilensis and B. subtilis subsp. Inaquosorum based on morphological, biochemical and cellular fatty acid profiling and further characterized through 16S rRNA gene sequences. On evaluation of these strains under microcosm conditions, inoculation of KMR-5 and KBY-1 strains of B. cereus significantly increased seed yield of soybean and wheat, but KMR-5, BHKD-6 and DBU-1 increased the Zn concentration in soybean and wheat seeds, when compared to other strains and un-inoculated control. Strain KMR-5 had increased both seed yield as well as zinc assimilation in soybean and wheat. Thus, this study selected three types of strains (1) yield enhancing strains, (2) Zn-enriching strains and (3) yield and zinc enrichment strain that could be utilized for improving seed yield and enrichment of zinc in seeds of soybean and wheat crops.

人間の健康に資する植物栄養学 : 鉄,亜鉛,ヨウ素の富化,硝酸イオン,カドミウムの低減(2006年秋田大会シンポジウムの概要)

人間の健康に資する植物栄養学 : 鉄,亜鉛,ヨウ素の富化,硝酸イオン,カドミウムの低減(2006年秋田大会シンポジウムの概要)

Direct enrichment of zinc(II) from and into ammoniacal media with commercialLIX84I

Abstract Solvent extraction of zinc(II) from and into ammoniacal media has been investigated using commercial LIX84I extractant. The effects of aqueous solution pH, total ammonia concentration and temperature on extraction of zinc(II)and ammonia stripping of loaded organic phases were examined. The extraction and stripping behaviors of zinc was also compared in the absence and presence of tributyl phosphate (TBP). The results indicate that LIX84I presents a good potential for zinc extraction in the ammonical solution. However, TBP has an antagonistic effect on zinc extraction with LIX84I. The extraction behavior of Zn(II) presents a special swing phenomenon in the both cases with and without TBP. The slope analysis and IR spectra indicate that each zinc ion can coordinate with two LIX84I molecules, whereas TBP molecules could bond with the LIX84I molecules, thus depressing zinc extraction. The zinc loaded organic phases can be effectively stripped with the ammoniacal media, especially increasing the ammonia concentration. Zinc stripping is more easy for the mixed system with TBP than the individual LIX84I system. Moreover, the extraction of zinc is an exothermic process, whereas the ammonia stripping of zinc is an endothermic process. The extraction and stripping isotherms indicate that the direct enrichment of zinc(II) from and into ammoniacal media can be achieved with the commercial LIX84I. These results are helpful for the hydrometallurgical recovery of zinc from the non-traditional resources.

Coupling of Insulin Secretion and Display of a Granule-resident Zinc Transporter ZnT8 on the Surface of Pancreatic Beta Cells

The islet-specific zinc transporter ZnT8 mediates zinc enrichment in the insulin secretory granules of the pancreatic beta cell. This granular zinc transporter is also a major self-antigen found in type 1 diabetes patients. It is not clear whether ZnT8 can be displayed on the cell surface and how insulin secretion may regulate the level of ZnT8 exposure to extracellular immune surveillance. Here we report specific antibody binding to the extracellular surface of rat insulinoma INS-1E cells that stably expressed a tagged human zinc transporter ZnT8. Flow cytometry analysis after fluorescent antibody labeling revealed strong correlations among the levels of ZnT8 expression, its display on the cell surface, and glucose-stimulated insulin secretion (GSIS). Glucose stimulation increased the surface display of endogenous ZnT8 from a basal level to 32.5% of the housekeeping Na+/K+ ATPase on the cell surface, thereby providing direct evidence for a GSIS-dependent surface exposure of the ZnT8 self-antigen. Moreover, the variation in tagged-ZnT8 expression and surface labeling enabled sorting of heterogeneous beta cells to subpopulations that exhibited marked differences in GSIS with parallel changes in endogenous ZnT8 expression. The abundant surface display of endogenous ZnT8 and its coupling to GSIS demonstrated the potential of ZnT8 as a surface biomarker for tracking and isolating functional beta cells in mixed cell populations.

Nutrient fortification approaches for enrichment of zinc enrichment in rice grain

Zinc is considered as fifth major nutrient deficiency after protein, calorie, Iron, vitamin A and Iodine, according to the International Zinc Nutrition there is a large mismatch between the zinc requirement and supply that is happening as of now in the state or elsewhere in the country. Present study was taken up to fortify the rice grain with zinc through soil and foliar sprays at different intervals and with different concentrations at Regional Agricultural Research Station, Anakapalle, Andhra Pradesh, ANGRAU during kharif, 2012 and 2013. Results revealed that highest grain yield of rice 5.41 and 5.26 t/ha during 2012 and 2013, respectively was recorded with application of 100% chemical fertilizers + 12.5 kg zinc sulphate/ha as soil application + two foliar sprays of zinc sulphate at 21 and 60 days after transplanting. Zinc enrichment in rice grain also followed that same trend as it was high in soil and foliar application of zinc fertilizer to the crop (15.60% increase over control).

Liquid Metal Embrittlement of Hot Stamped Galvannealed Boron Steel Sheet – Effect of Heating Time on Crack Formation –

Galvannealed (GA) boron steel sheets were subjected to direct hot stamping tests (V-bending) to investigate crack formation behavior. Specimens were heated at 1173 K (900°C) in a combustion gas furnace and hot stamped on a cooled V-shaped die. The heating time was varied to alter the composition, phase, and microstructure of the coating layer. Generally, the reaction zone between the zinc coating layer and metal substrate could not be observed by scanning electron microscopy. For certain specimens, crack penetration occurred along primary austenitic grain boundaries of the substrate, with zinc enrichment observed at the crack sidewalls suggesting the occurrence of liquid metal embrittlement (LME) of the base metal. LME-induced cracking resulted when the coating layer corresponded to a biphasic Fe–Zn ferrite/liquid zinc structure of the binary Fe–Zn phase diagram during heating in the furnace. For cracked specimens, the maximum crack depth increased with increasing total X-ray diffraction intensity of δ and η phases in the coating layer of hot-stamped samples, being positively correlated with the amount of “liquid zinc” in the coating layer.

Tracing of anthropogenic zinc sources in coastal environments using stable isotope composition

The use of zinc isotopes to trace anthropogenic sources in coastal areas has been tested in this study. We determined the stable isotopic composition of zinc in sediment cores, suspended particulate matter (SPM) and rocks collected at the Sepetiba Bay (southeastern Brazil), an estuarine lagoon heavily impacted by metallurgic activities. These isotopic signatures were compared with those from willemite ore, which represent the main mineral refined by the major industrial source of zinc. The aim was to test if this tracer system enables to identify sources and sinks of anthropogenic zinc and to reconstruct the temporal and spatial evolution of zinc contamination. The zinc isotopic compositions (expressed using the δ66Zn notation relative to the JMC 3-0749-L solution) showed significant variations in the sediment cores, the SPM, and willemite ore minerals, ranging between −0.01 and +1.15‰. Spatial and temporal analysis of sediments samples fit well in a model of mixing involving three main end-members: i) Terrestrial background (δ66ZnJMC=+0.28±0.12‰, 2σ); ii) marine detrital material (δ66ZnJMC=+0.45±0.03‰, 2σ); and iii) a major anthropogenic source associated with electroplating wastes released into the bay (δ66ZnJMC=+0.86±0.15‰, 2σ). Sediment cores collected in the mud flats showed high correlation between δ66Zn and zinc enrichment factors, suggesting good preservation of the isotopic records of natural and anthropogenic sources. The sediment core sampled from a mangrove wetland located in a zone impacted by the metallurgy presented levels of zinc up to 4% (sediment dry weight) and preserved the isotopic signatures of electroplating wastes, despite evidences that post depositional processes slightly changed the isotopic signatures in some layers from this core toward heavier δ66ZnJMC values (above +1.0‰). A two component mixing model suggests contributions of this major anthropogenic Zn source up to nearly 80% during periods of electroplating activities. Our work suggests that Zn isotope compositions of sediments are reliable tracers of anthropogenic sources and, therefore, can be useful to improve environmental monitoring efforts in coastal systems.

A practicable method for zinc enrichment in lettuce leaves by the endophyte fungus Piriformospora indica under increasing zinc supply

Zinc (Zn) deficiency is well-documented public health issue and a significant factor hampering to crop production. There is a close overlap between soil deficiency and human deficiency of Zn, indicating a need for increasing Zn content in crops and vegetables. In this study, the effects of endophytic fungus Piriformospora indica and Zn treatment on growth parameters, chlorophyll amounts, and Zn and some other micronutrient concentrations in Lactuca sativa cv. Siyahoo plants were investigated. The experiment was carried out including two treatments (P. indica inoculation and non-inoculation), each having four Zn concentrations (0, 2.5, 5 and 10mg/l Zn added to full-strength Hoagland solution) in a sand culture substrate. By increasing Zn concentration in sand substrate, growth parameters, chlorophyll content and leaf Zn concentration were significantly increased from 34.1 to 185.1μg/g DW, whereas leaf iron (Fe) concentration was decreased. Significant increase in various parameters including growth, chlorophyll content and leaf Zn concentrations (7.6 fold) were observed in plants inoculated with P. indica under supplemented concentration of 10mg/l Zn. Results from this study indicate that P. indica inoculation with Zn supplementation can help in Zn enrichment in lettuce plants.

Film growth and alloy enrichment during anodizing AZ31 magnesium alloy in fluoride/glycerol electrolytes of a range of water contents

The effect of anodizing AZ31 magnesium alloy in a fluoride/glycerol electrolyte containing from 1 to 40 vol.% water on the compositions of the anodic film and the underlying alloy has been investigated. A range of constant current densities and water contents of the electrolyte were employed. Scanning and transmission electron microscopy, with energy-dispersive X-ray spectroscopy, X-ray diffraction and ion beam analyses were used to analyse the anodized alloy. Barrier films, containing fluoride and oxide species, were formed above the matrix, at high current efficiency; a porous film was formed above Al-Mn intermetallic particles. The current density and the water content of the electrolyte affected the O:F atomic ratio and the ionic transport in the films. Significant enrichments of zinc and aluminium were generated in a thin layer of the matrix immediately beneath the film under all conditions of anodizing, with the enrichment of zinc reaching 6.2×1015 at cm−2 in the enriched alloy layer. The cause of the enrichments and the consequences to film growth are discussed.

Spectral cathodoluminescence analysis of hymenopteran mandibles with different levels of zinc enrichment in their teeth

The inclusion of Zn in insect mandibles affects their hardness and is functional to their use during feeding or reproducing. However, little is known on the chemical/structural base of Zn enrichment. Here, we found that cathodoluminescence (CL) technique revealed two different types of CL spectra in the mandibles of Hymenoptera, depending on the Zn enrichment level assessed by Energy Dispersive X-ray Spectroscopy (EDS). Individuals having negligible traces to low % of Zn in their mandible teeth (≤3 wt%) presented a wide band of luminescence in the visible range which resembled those observed in the CC structures of graphite. This spectrum is probably characteristic for un-enriched cuticle, since it did not differ from those obtained from the Zn-lacking inner part of mandibles. Individuals with moderate to high % of Zn in their mandible teeth (≥7 wt%), instead, presented additional CL peaks in the ultraviolet range. Comparisons with different minerals of Zn suggest that these peaks could be related with OZnO bonds, with hydroxyl groups and with zinc-chlorine links (in agreement with Cl high levels detected by the EDS). Being a non-destructive technique, CL allows large comparative studies of the chemistry of metal-enriched insect cuticle even using unique specimens, such as those deposited in Natural History Museums.

Composition and Formation of Gabbro-Peridotite Hosted Seafloor Massive Sulfide Deposits from the Ashadze-1 Hydrothermal Field, Mid-Atlantic Ridge

This paper presents mineralogical and geochemical data on seafloor massive sulfides (SMS) from the Ashadze-1 hydrothermal field at the Mid-Atlantic Ridge (MAR). The Ashadze-1 deposit is associated with the uplifted lower crust and upper mantle (oceanic core complex, OCC) of the MAR segment characterized by asymmetric mode of accretion. The OCC is represented by deep-seated gabbro-peridotite rocks exhumed on the rift valley slope along the detachment fault, during seafloor spreading. Hydrothermal processes in OCC environments result in different deposit composition and morphology compared to basalt-hosted systems. Abundant chimneys and enrichment in particular metals, including copper, zinc, gold, cobalt and tin are typical for this type of SMS deposit. The Ashadze-1 deposit is considered an example of a hydrothermal system in the initial stage of evolution marked by the young age of the sulfides (&lt;7.2 kyr). The mineralogy of Ashadze-1 reflects primary ore-forming processes unaffected by post formation alteration. We propose a model for the primary ore-forming hydrothermal process in an ultramafic-hosted environment on the modern seafloor.

Effect of Zinc Enrichment on Growth and Nutritional Quality in Pea Sprouts

Zinc (Zn) is essential in plant nutrition and a fundamental component. Zn deficiency causes 450,000 deaths of children under 5 years of age every year. The slight lack of Zn leads to more diseases in humans, such as anorexia, loss of appetite, smell and taste failure. Thus, biofortification is used to provide the Zn nutritional status of plant food. The present study was conducted to investigate the effects of exogenous application of Zn by soaking and spraying on Zn contents, nutrition composition and antioxidant capacity in sprout. The results showed that plant growth was gradually increased from 10 to 50 mg L-1 of Zn; the nutrient values were also incremented by Zn of certain concentrations; and applied Zn treatment improved the total antioxidant capacity and contents of free amino acid. However, when Zn was over 50 mg L-1, it resulted in reductions of nutrition value and antioxidant capacity, inhibiting the sprout growth. These results indicated that the optimal dose of Zn by soaking or spraying was 40-50 mg L-1; and the impact of spraying was better than that of soaking. It was effective to enrich Zn content in certain extent by soaking or spraying, which could increase the nutrition value and antioxidant capacity as functional foods.

On the Evolution of Cathodic Activity during Corrosion of Magnesium Alloy AZ31B in a Dilute NaCl Solution

Sequential potentiodynamic polarization and scanning vibrating electrode technique measurements were made on Mg alloy AZ31B immersed in dilute 0.05 M NaCl solution to corroborate the suspected role of noble metal (relative to Mg) solute enrichment at the filament/alloy interface in sustaining the cathodic activation exhibited by corrosion filaments. The electrochemical measurements revealed that the extent of cathodic activation (i.e. current density) measured over a corrosion filament was sustained with immersion time. This resulted in a continual increase in the total anodic current measured over the AZ31B surface as new filaments initiated and propagated. The sustained cathodic activation coupled with observations of zinc (Zn) enrichment at the filament/alloy interface during the life of a corrosion filament is argued to be indicative of a solute enrichment mechanism being a significant factor in this process.

Zinc-Rich Copper Catalysts Promoted by Gold for Methanol Synthesis

In this study, we gathered further understanding of the function of the components in the Cu-ZnO-Al2O3 catalyst for methanol synthesis from mixed syngas feeds (CO/CO2/H2) to rationally develop systems displaying superior performance. In order to unravel the role of ZnO in the hydrogenation of the preferred methanol source, CO2, and in the (reverse) water–gas shift ((R)WGS) reaction, we tested coprecipitated materials with variable surface zinc content under industrially relevant conditions (5.0 MPa, 503–543 K). We found that a surface enrichment in zinc leads to higher activity and selectivity due to (i) the enhancement of the unique synergistic Cu-ZnO interactions boosting CO2 hydrogenation, (ii) the inhibition of the RWGS reaction which produces the undesired CO, and (iii) the electronic stabilization of the Cu sites against reoxidation by CO2 or H2O. Thus, a catalyst with a surface Zn/(Cu + Zn) ratio of 0.8 displayed superior catalytic properties than a commercial benchmark sample, which featured only ...

Strong metal-support interaction and alloying in Pd/ZnO catalysts for CO oxidation

Pd/ZnO catalysts with different Pd content have been synthesized, thoroughly characterized and investigated with regard to their reduction behavior in hydrogen or carbon monoxide containing atmospheres, by applying CO-chemisorption, photoelectron spectroscopy, X-ray diffraction, electron microscopy, TPR and DRIFTS techniques. As a catalytic test reaction, CO-oxidation has been applied. The interaction of the noble metal with the support has been revealed in a way that can distinguish between alloying and other surface spreading/wetting phenomena, induced by strong metal-support interaction (SMSI). It was found that while alloy formation promoted CO-oxidation activity additional ZnOx formation by SMSI had the opposite effect. Zinc enrichment at the surface was detected during reduction of the catalysts, depending on the reducing agent and the Pd particle size.

A Drosophila model identifies a critical role for zinc in mineralization for kidney stone disease.

Ectopic calcification is a driving force for a variety of diseases, including kidney stones and atherosclerosis, but initiating factors remain largely unknown. Given its importance in seemingly divergent disease processes, identifying fundamental principal actors for ectopic calcification may have broad translational significance. Here we establish a Drosophila melanogaster model for ectopic calcification by inhibiting xanthine dehydrogenase whose deficiency leads to kidney stones in humans and dogs. Micro X-ray absorption near edge spectroscopy (μXANES) synchrotron analyses revealed high enrichment of zinc in the Drosophila equivalent of kidney stones, which was also observed in human kidney stones and Randall’s plaques (early calcifications seen in human kidneys thought to be the precursor for renal stones). To further test the role of zinc in driving mineralization, we inhibited zinc transporter genes in the ZnT family and observed suppression of Drosophila stone formation. Taken together, genetic, dietary, and pharmacologic interventions to lower zinc confirm a critical role for zinc in driving the process of heterogeneous nucleation that eventually leads to stone formation. Our findings open a novel perspective on the etiology of urinary stones and related diseases, which may lead to the identification of new preventive and therapeutic approaches.

Zinc enrichment in wheat genotypes under various methods of zinc application

Around half of the cereal growing soil in the world are zinc (Zn)-deficient and it severally affects the health of plants, animals and humans. In order to investigate the enrichment of Zn in cereals a pot experiment was conducted in two contrasting wheat genotypes viz., UP2628 (Zn efficient) and UP262 (Zn inefficient) under different meth ods of Zn application such as control (0 Zn), soil application (5 mg Zn/kg soil tagged with 3.7 MBq of 65 Zn/pot), foliar spray of 0.5% ZnSO 4 at 30, 60 and 90 days (tagged with 925 KBq of 65 Zn/pot), soil application (5 mg Zn/kg soil tagged with 3.7 MBq of 65 Zn/pot) + foliar spray of 0.5% ZnSO 4 at 30, 60 and 90 days (tagged with 925 KBq of 65 Zn/pot). Cultivars showed marked difference in 65 Zn accumulation and grain Zn content. In both contrasting genotypes the highest Zn content in grains was recorded under soil application + foliar spray of Zn fertilizers. Both UP262 and UP2628 showed similar accumulation of 65 Zn in leaves however, UP2628 exhibited better translocation efficiency and accumulated higher 65 Zn in stem and grains than UP262.

Response of a phytoplanktonic assemblage to copper and zinc enrichment in microcosm.

The response of a laboratory-raised phytoplankton assemblage to copper and zinc enrichment was studied. Higher intracellular accumulation of both the test metals caused disappearance of metal sensitive species, loss of diversity and species richness, reduced growth rate, Chl a and biovolume; however, the community could recover after 14days of incubation. Cyanobacteria showed marked sensitivity to both the test metals besides some diatoms, such as, Cyclotella meneghiniana and Melosira granulata. Metal enrichment enhanced the relative abundance of species like Scenedesmus quadricauda, Oocystis borgei, Achnanthes exigua, Fragilaria capucina and Nitzschia amphibia, and these were apparently metal tolerant. Cu and Zn stress induces formation of lipid bodies (bigger in size as well as in number) and morphological abnormalities in diatoms. Among these two metals, Cu impact was higher than Zn despite the fact that the intracellular accumulation of Zn was higher than Cu. Deformed raphe and mixed deformities in diatoms were exclusively found under heavy metal stress which was well supported by regression analysis. Finally the present study gives new insight for using diatoms as an effective tool for biomonitoring and biofuel production.

Distribution patterns and enrichment of lead, zinc and copper in surface sediments of the central Portuguese shelf and upper slope

Geographic patterns of Cu, Pb and Zn enrichment on the Lisbon-Setubal-Sines continental shelf and upper slope (central Portuguese margin) were studied in this paper to gain insight into current pathways of trace metal dispersal. Our study is based on the analysis of elemental concentrations and mineralogy of surface sediment samples collected offshore one of the most industrialised areas of Portugal. On the Lisbon-Setubal-Sines shelf concentrations of Al, Fe, Mg, Ti within the fine-grained sediment fraction appear to a large extent related to the amount of fine-grained fraction in the bulk sediment. The extent of enrichment of trace metals in the studied area follows the sequence: Pb > Zn > Cu. Generally, the enrichment of trace metals tends to decrease in offshore direction suggesting that the excess of trace metals must be derived from land. The areas of the Lisbon-Setubal-Sines shelf most affected by enrichment of trace metals include the Tagus and Sado mud patches and the inner shelf between Troia and Sines, including the areas close to the Sado outlet and the area adjacent to the St. Andre and Melides coastal lagoons, which highlights the nearby estuaries and the lagoons as likely sources for the enrichment. In addition, the more widespread enrichment of Pb in sediments points to contributions from atmospheric inputs. The similarity between the results here presented with later data from other authors allows concluding that our results provide a representative view of trace metal enrichment in surface sediments between 1980 and 2000.