Silver Thiosulfate Complex Research Articles

Effects of Silver Thiosulfate Complex (STS), Sucrose and Combined Pulse Treatments on the Vase Life of Cut Snapdragon Flowers

Sensitivity to ethylene of cut snapdragon (Antirrhinum majus L. cv. Yellow Butterfly) flowers and the effects of pulse treatments with either silver thiosulfate complex (STS), sucrose or in combination on vase life were investigated. Exposure to ethylene at 2 and 10 μL L−1 for 48 h induced abscission of petals in cut flower spikes, suggesting that snapdragon flowers are moderately sensitive to ethylene. Cut snapdragon spikes were treated with 50, 75, 100 and 125 g L−1 sucrose with or without 0.2 mM STS for 24 h. Treatment with STS alone slightly extended the vase life of cut flowers, but treatment with sucrose alone extended the vase life of cut flowers only with increasing concentration of sucrose up to 100 g L−1. Treatment with STS plus sucrose was more effective in promoting floret opening and extending vase life than that with sucrose alone at all sucrose concentrations tested. The size of florets opened after harvest was greater for treatment with sucrose alone or STS plus sucrose treatments than in control or STS alone treatments. Concentrations of aurones, pigments responsible for yellow color in the petals, were higher for treatment with sucrose or STS plus sucrose than in control or STS alone treatments. Soluble carbohydrate concentration in the petals was highest for treatment with sucrose, followed by STS plus sucrose, whereas it was lowest in STS treatment. These findings suggest that pulse treatment with STS plus sucrose is the most effective for extending vase life of cut snapdragon flowers and for improving pigmentation.

Removal of various components from fixing rinse water by anion-exchange resins

The subject of the investigation has been the possibility of anion extraction from fixing process rinse waters contaminated by Br −, S 2O 3 2−, SO 4 2−, SO 3 2−, CH 3COO − and silver thiosulfate complex anions using Amberlite IRA-93 RF, Purolite A-845, Purolite A-500 and AB-17-8 anion-exchange resins. Weak base Cl − forms of both Amberlite IRA-93 RF and Purolite A-845 resins remove silver complexes and SO 3 2− anions most effectively, while strong base Cl − forms of Purolite A-500 and AB-17-8 resins sorb preferably Br − anions along with silver complexes. The seeming sorption capacities of Cl − forms of Amberlite IRA-93 RF, Purolite A-845, Purolite A-500 and AB-17-8 resins estimated under the test conditions were 1.05, 1.95, 0.97 and 1.82 meq/cm 3, respectively. The elution of anions from loaded resins does not run in full and the effectiveness of the regeneration depends on the anionic form of resin and solution concentration. The Cl − form of Purolite A-845 resin demonstrates the best sorption capacity among the tested resins. When the sorption capacity is not depleted, this resin sorbs in full all anions, with the exception of the CH 3COO − anion, which is sorbed only partially.

Hydrometallurgical recovery of silver from waste silver oxide button cells

In recent years, recycling of household batteries has attracted much attention mainly with respect to environmental aspects in addition to the savings. Small silver oxide primary cells used in electric watches become a waste after their life is over. Recycling procedures are needed to prevent any environmental impact from these wastes and to recover the value inherent in the scrap. Smelting and electrolytic methods are discussed for silver recovery from this battery waste. Acid leaching of waste batteries and precipitation of silver as silver chloride followed by smelting at 1000 °C yields a silver recovery of about 83%. An electrolytic route is studied as an alternative to the smelting operation and involves the electrodeposition of silver with higher purity from a silver thiosulfate complex prepared from silver chloride. The electrolysis is potentiostatically controlled at a potential of −0.400 to −0.600 V (SCE) for avoiding side-reactions such as the sulfiding of silver. Although recovery methods have been identified in principle, their suitability for mixed small battery waste and economic factors have yet to be demonstrated.

A novel fiber‐coated strong base‐type anion exchanger with superfast kinetics. Removal and recovery of silver thiosulfate from aqueous solutions

AbstractA commercial acrylic fiber with 92% (w/w) acrylonitrile content was partially hydrolyzed converting a fraction of the nitrile (CN) groups to carboxylic acid (COOH) groups, to coat the fiber with polyethylenimine (PEI) resin, which was then crosslinked with glutaraldehyde and further quaternized with ethyl chloroacetate to produce a novel strong‐base anionic exchanger in the form of fiber. Designated as PAN(QPEI.XG)(Cl−), the fibrous sorbent was compared with a commercial bead‐form resin Amberlite IRA‐458(Cl−) in respect of sorption capacity, selectivity, and kinetics for removal of silver thiosulfate complexes from aqueous solutions. Though the saturation level of [Ag(S2O3)2]3− on PAN(QPEI.XG)(Cl−) is considerably less than that on IRA‐458(Cl−), the gel‐coated fibrous sorbent exhibits, as compared to the bead‐form sorbent, a significantly higher sorption selectivity for the silver thiosulfate complex in the presence of excess of other anions such as S2O32−, SO42−, and Cl−, and a remarkably faster rate of both sorption and stripping. The initial uptake of the sorbate by the fibrous sorbent is nearly instantaneous, reaching up to ∼80% of the saturation capacity within 10 s, as compared to only ∼12% on the bead‐form sorbent. The high initial rate of uptake fits a shell‐core kinetic model for sorption on fiber of cylindrical geometry. With 4M HCl, the stripping of the sorbed silver complex from the fibrous sorbent is clean and nearly instantaneous, while, in contrast, a much slower rate of stripping on the bead‐form sorbent leads to its fouling due to a slow decomposition of the silver thiosulfate complex in the acidic medium. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2604–2613, 2006

Senescence of Eustoma Flowers as Affected by Pollinated Area of the Stigmatic Surface

Senescence of Eustoma flowers is accelerated by pollination which is accompanied by an increase in ethylene production by flowers. We investigated the influence of pollinating different areas of the stigmatic surface on senescence in the flowers of 6 Eustoma cultivars. Anthers were removed from the flowers whose stigma had not yet opened. After the stigmas opened, freshly collected pollen from anthers of same cultivar were placed on them. The pollination levels on stigma were all area, 1/8 area or none (control). Senescence of flowers was significantly accelerated by all and 1/8 area pollination compared with the control. All area-pollinated flowers wilted significantly earlier than did 1/8 area-pollinated ones in three cultivars. In the remaining three cultivars, senescence of flowers by all area pollination tended to be earlier than that of 1/8 area pollination. In ‘Asuka-no-nami’ flowers, ethylene production of flowers rapidly increased 1 day after all area pollination. However, in flowers with 1/8 area pollination, ethylene production slowly increased for 3 days after pollination. A large number of pollen tubes reached the base of the style 2 days after pollination in the all area-pollinated flowers, but on 3rd day in the 1/8 area-pollinated flowers. All area-pollinated flowers required silver thiosulfate complex (STS) at high concentration to delay senescence induced by pollination, compared with the 1/8 area-pollinated flowers. These results suggest that in Eustoma flowers, senescence that is induced by pollination, depends on the pollinated area of the stigmatic surface which resulted in ethylene production.

Precipitation of Silver-Thiosulfate Complex and Immobilization of Silver by Cupriavidus metallidurans CH34

Cupriavidus metallidurans CH34 is a facultative chemolithotrophic bacterium that possesses two megaplasmids (pMOL28 and pMOL30) that confer resistance to eleven metals. The ability of Cupriavidus metallidurans CH34 to resist silver is described here. Electronic microscopy, energy-dispersive X-ray (EDX) and X-ray diffractometry (DRX) observations revealed that C. metallidurans CH34 strongly associated silver with the outer membrane, under chloride chemical form. Using derivate strains of C. metallidurans CH34, which carried only one or no megaplasmid, we show that this resistance seems to be carried by pMOL30.

Electroless versus electrodriven deposition of silver crystals in polyaniline: Role of silver anion complexes

Electrocrystallization of silver is studied at polyaniline-coated electrodes using silver cations and two silver anion complexes (silver thiosulfate and silver–EDTA) as reducing species. Use of the silver thiosulfate complex results in a significant shift of the silver deposition potential window in the negative direction and highly impeded metal crystallization. The silver cation and silver–EDTA plating solutions allow to perform both electrodriven and electroless metal deposition. Number and size of silver crystals obtained by the two deposition methods in the different plating solutions are compared. Electroless precipitation in the silver–EDTA solution results in the highest number (∼10 8 cm −2) of small-sized crystals. This result is discussed in terms of the special role of the EDTA anions for the redox state of the polyaniline layers. It is demonstrated that factors such as polyaniline redox charge, concentration of reducing ions and dipping time allow effective control over the amount of electroless deposited metal.

Effects of Silver Thiosulfate Complex (STS), Sucrose and their Combination on the Quality and Vase Life of Cut Eustoma Flowers

Effects of Silver Thiosulfate Complex (STS), Sucrose and their Combination on the Quality and Vase Life of Cut Eustoma Flowers

Design of a Flow-Through Cell for Analysis of Thiosulfate in Solutions Containing Copper and Ammonia

Thiosulfate is a potential alternative to cyanide in the recovery of gold. However, in the presence of copper and ammonia the solution chemistry is complex, and the thiosulfate concentration continually decreases due to its oxidation. The determination of the thiosulfate concentration by traditional techniques is difficult in leach solutions due to the interference from copper and other polythionates. A flow injection analysis method for thiosulfate has been developed which utilizes an electrochemical cell containing platinum and silver electrodes. The basis of the analysis is that the silver electrode measures the formation of the silver thiosulfate complex plus the oxidation/reduction of copper(I)/copper(II). In order to correct for copper, the charge for copper(I)/copper(II) is measured on the platinum electrode, and this is subtracted from the silver charge measured on the silver electrode. This provides a simple and robust analytical method for the analysis of thiosulfate in solutions used for gold leaching. © 2004 The Electrochemical Society. All rights reserved.

Ethylene-induced Leaf Yellowing in Cut Chrysanthemums (Dendranthema grandiflora Kitamura)

Twelve cultivars of cut flowering chrysanthemums (Dendranthema grandiflora Kitamura) were exposed continuously to air with or without 1 ppm ethylene and their leaf color was measured with a chromameter. When leaves of six cultivars, including 'Syuho-no-chikara' and 'Seiko-no-makoto', were exposed to ethylene, they turned yellow, but others did not respond to ethylene. Similar varietal sensitivity to ethylene and consequent leaf yellowing were observed in resetted and elongating vegetative shoots. Pulsing with 0.2 mM anionic silver thiosulfate complex (STS) completely inhibited leaf yellowing in the ethylene-containing atmosphere. These results indicate that yellowing of the leaves of some chrysanthemum cultivars is induced by ethylene.

Extension of Vase Life of Cut Narcissus tazetta var. chinensis Flowers by Combined Treatment with STS and Gibberellin A3

The effects of pulse treatment with gibberellin A3 (GA3), silver thiosulfate complex (STS), and with or without sucrose on chlorophyll degradation and vase life of cut flowers of Narcissus tazetta var. chinensis were investigated. The 20-hr pulsing treatment with STS extended the vase life of cut flowers of N. tazetta var. chinensis. Pulse treatments with GA3 delayed degradation of chlorophyll, but extended the vase life only slightly, whereas that with sucrose was ineffective, probably because the concentration of soluble carbohydrates in the stems and floral organs other than the petals was already high. Pulse treatments with STS at 0.1mM in combination with GA3 at 0.5 or 1mM were optimum for extending the vase life and preservation of leaf chlorophyll of N. tazetta var. chinensis.

Efficacy of inhibitors of ethylene binding in improvement of the postharvest characteristics of potted flowering plants

Pre-treatment of potted plants of Campanula carpatica cultivars Dark Blue and Blue Clips and Schlumbergera truncata cultivar Dark Marie with the volatile ethylene binding inhibitor 1-methylcyclopropene (1-MCP) inhibited the effects of exogenous ethylene (bud abscission and wilting of flowers). In an ethylene-free simulated interior environment, display life of the 1-MCP treated plants was unaffected (Campanula) or slightly greater (Schlumbergera) than that of the controls, although not as good as that of plants pre-treated with the anionic silver thiosulfate complex (STS). Differences in effects of both blockers of ethylene binding sites are discussed.

Role of Ethylene on Flower Senescence of Torenia.

Flower senescence of Torenia fournieri was investigated in relation to ethylene production and sensitivity. Ethylene production of flowers increased with flower senescence ; pistil contributed to climacteric increase of ethylene production whereas other organs such as the petal, stamen, and calyx did not. Flowers were not sensitive to ethylene on the day of anthesis, but developed sensitivity as the flower senesced. Pollination and wounding of stigma markedly accelerated abscission of flowers, which was accompanied by climacteric ethylene production. Climacteric ethylene, following pollination and stigma wounding, was mainly produced by the pistil, particularly the style with stigma. The abscission of the intact, pollinated and stigma-wounded flowers was significantly inhibited by treatment with silver thiosulfate complex (STS), an ethylene action inhibitor. These results clearly show that the flower senescence of Torenia is mainly regulated by ethylene.

Effect of Silver Thiosulfate Complex (STS) in Combination with Sucrose on the Vase Life of Cut Sweet Pea Flowers.

Cut sweet pea (Lathyrus odoratus L., cv. Diana) flowers were treated with 1) 100 g·liter-1 sucrose for 16 hr, 2) 0.2 mM silver thiosulfate complex (STS) for 2 hr, 3) 0.2 mM STS for 2 hr followed by 100 g·liter-1 sucrose for 16 hr, and 4) water (control), and the effects of the treatments on vase life were evaluated. Compared to the control, all treatments promoted floret size, advanced opening, and extended longevity. Treatment with STS followed by sucrose was the most effective in promoting floret opening as well as extending longevity. Anthocyanin concentrations were increased by treatments with sucrose alone or STS followed by sucrose. Ethylene production was inhibited by all treatments, particularly in the presence of sucrose. These results show that STS followed by sucrose is more effective than STS alone in improving the vase life of cut sweet pea flowers.

Bioaccumulation and toxicity of silver compounds: A review

AbstractA eview of the literature revealed that bioaccumulation of silver in soil is rather low, even if the soil is amended with silver‐containing sewage sludge. Plants grown on tailings of silver mines were found to have silver primarily in the root systems. In marine and freshwater systems, the highest reported bioconcentration factors (BCFs) were observed in algae (>105), probably because of adsorption of the dissolved silver (<0.45 μm fraction) to the cell surface. In herbivorous organisms (e.g., zooplankton and bivalves), the BCF was lower by about two orders of magnitude. Low amounts of silver were assimilated from food with no substantial biomagnification. In carnivores (e.g., fish), the BCF was also lower by one order of magnitude with no indication of biomagnification. Toxicity of silver occurs mainly in the aqueous phase and depends on the concentration of active, free Ag+ions. Accordingly, many processes and water characteristics reduce silver toxicity by stopping the formation of free Ag+, binding Ag+, or preventing binding of Ag+to the reactive surfaces of organisms. The solubility of a silver compound, and the presence of complexing agents (e.g., thiosulfate or chloride), dissolved organic carbon, and competing ions are important. In soil, sewage sludge, and sediments, in which silver sulfide predominates, the toxicity of silver, even at high total concentrations, is very low. The highly soluble silver thiosulfate complex has low toxicity, which can be attributed to the silver complexed by thiosulfate. Silver nitrate is one of the most toxic silver compounds. The toxic potential of silver chloride complexes in seawater is and will be an important issue for investigation. Aquatic chronic tests, long‐term tests, and tests including sensitive life stages show lower toxicity thresholds (˜1 μg Ag+/L). The organisms viewed as most sensitive to silver are small aquatic invertebrates, particularly embryonic and larval stages.

Partitioning and Effects of Silver in Amended Freshwater Sediments

Sediments that represented a wide range of characteristics were amended with silver compounds to observe partitioning and bioavailability. In laboratory studies, silver partitioning to particulates, sediment pore water, and overlying water was measured and bioavailability of silver was determined using Hyalella aztecain 10-day sediment toxicity tests. Three silver compounds were used as sources of silver for this study: silver nitrate, silver chloride, and silver thiosulfate complex. Sediment amendment procedures were adjusted as necessary depending on the characteristics of the individual compounds. Several sediment characteristics such as organic carbon, pH, redox, and acid volatile sulfides regulated silver partitioning and bioavailability. Bioavailability of silver was correlated with the overlying water concentration of silver. Ten-day LC 50values ranged from 1.62 to 379.7 mg Ag/kg for H. aztecaexposed to sediments amended with AgNO 3. In laboratory experiments, silver chloride and silver thiosulfate were orders of magnitude less toxic and bioavailable than silver nitrate, with 10-day LC 50values greater than the highest concentrations of AgCl and silver thiosulfate complex amended to sediments (2560 and 1125 mg Ag/kg, respectively).

Inhibitors of Ethylene Biosynthesis and Action Do Not Prevent Injury to Wheat Seedlings Infested with Schizaphis graminum (Homoptera: Aphididae)

Experiments were conducted to determine whether inhibitors of ethylene biosynthesis and action can prevent symptoms of aphid damage to wheat seedlings. ‘TAM 107’ wheat, Triticum aestivum L., seedlings infested with biotype G greenbugs, Schizaphis graminum (Rondani), for 6 h developed chlorosis and necrotic spots within 4 d after the aphids were removed. AVG (1 mM 2-aminoethoxyvinylglycine), an ethylene biosynthesis inhibitor, reduced ethylene production but not development of lesions or loss of chlorophyll from infested seedlings. STS [silver thiosulfate complex (0.5 mM AgN03, 2.0 mM Na thiosulfate)], an inhibitor of ethylene action, did not prevent a reduction in chlorophyll concentration or the development of lesions. A secondary objective was to determine how the ethylene biosynthetic pathway was differentially affected by aphid biotypes previously shown to stimulate high or low levels of ethylene. ‘Largo’ and TAM 107 wheat seedlings were infested with biotype E or G greenbugs, then harvested after 1, 6, or 48 h. Both wheat genotypes are susceptible to biotype G. TAM 107 is susceptible to biotype E and Largo is resistant. Increased ethylene production 6 h after seedlings were exposed to biotype G was associated with an increase in ACC (1-aminocyclopropane-l-carboxylic acid, the immediate precursor of ethylene) and EFE (ethylene-forming-enzyme) activity in both wheat genotypes. Ethylene production, ACC content, and EFE activity declined by 48 h, concomitant with an increase in MACC (N-malonyl-ACC, an inactive conjugate of ACC). Biotype E triggered a smaller increase in ethylene production than biotype G. ACC levels were not affected by biotype E, but EFE activity increased by 33% in Largo and 151% in TAM 107 after 6 h. Ethylene production from greenbug-infested wheat seedlings was controlled primarily by ACC content. Ethylene appeared to be a symptom, not a mediator of green bug-induced injury.

Supplemental irradiance and STS improve the display life of Dicentra species forced as flowering potted plants

During the display life of potted plants of three Dicentra species ( Dicentra eximia, Dicentra formosa, and Dicentra spectabilis), more flowers opened if the plants were treated before harvest with the anionic silver thiosulfate complex (STS). This increase in flower number resulted in a 75% increase in the display life of D. eximia (to 14 days) and a 65% increase in display life of D. formosa (to 28 days). A similar effect was achieved by producing the plants under supplementary irradiance, which also increased plant height and decreased production time. Height of D. spectabilis could be controlled by application of daminozide, and this regulator had no effect on forcing time, flower number or display life of the plants.

テトラエトキシシランの加水分解物による抗菌剤表面被覆と耐熱性

Antimicrobial materials were synthesized with a silver thiosulfate complex on silica gel. Their thermal stability was improved by coating the surface with hydrolyzed tetraethoxysilane. The chemical interaction was presumed present on silica gel with coated materials based on the improvement with the increasing amount of TEOS used and the absence of improvement with the coating by less interactive materials.

Effects of 1-MCP on the vase life and ethylene response of cut flowers

Pretreatment for 6 h with low concentrations of 1-MCP (1-Methylcyclopropene, formerly designated as SIS-X), a cyclic ethylene analog, inhibits the normal wilting response of cut carnations exposed continuously to 0.4 μl·l−1 ethylene. The response to 1-MCP was a function of treatment concentration and time. Treatment with 1-MCP was as effective in inhibiting ethylene effects as treatment with the anionic silver thiosulfate complex (STS), the standard commercial treatment. Other ethylene-sensitive cut flowers responded similarly to carnations. In the presence of 1 μl·l−1 ethylene, the vase life of 1-MCP-treated flowers was up to 4 times that of the controls.