Hydrophile Polymergele mit reaktiven Gruppen, 3. Mitt.: Chelatharze mit Formazan-Ankergruppen auf Basis von Saccharosemethacrylaten

The preparation and properties of hydrophilic chelating resins containing formazans as functional groups are described. Sucrosemethacrylat-gels with primary aromatic amino groups were diazotised and coupled with various substituted phenylhydrazones yielding gels with formazans as chelating anchor groups. The capacities of the gels were max. 1,6 mmol/g. The recycle of adsorption and elution was found to be satisfactory for Co²⁺ and Pb²⁺ whereas only 60% of the bonded Hg^2– could be recovered reversibly.

     

Hydrophile Polymergele mit reaktiven Gruppen, 2. Mitt.: Chelatharze auf Basis von Glucose- und Saccharosemethacrylaten

A widely applicable method for the preparation of chelating resins based on glucose- and sucrosemethacrylate-gels is described. Primary aromatic amino groups were bonded to the carrier by esterification with 4-nitrobenzoylchloride and subsequent reduction of the nitro groups with sodium dithionite. Diazotation and coupling with various chelating ligands (8-hydroxyquinoline, dithizone, anthranilic acid, salicylic acid and pyrogallol) afforded chelating resins with capacities of max. 1.7 mmol/g. Sucrosemethacrylate-gels were etherified with 4-nitrobenzylchloride, epichlorohydrin, 4-nitrophenyl glycide ether (IIb), acrylonitrile and 4-nitrophenylacrylamide (IVb). Reaction of the gels with IIb or IVb and subsequent reduction of the nitro groups yielded reactive carriers with ether-linked primary aromatic amino groups. Diazotation and coupling with 8-hydroxyquinoline yielded chelating resins. The capacities of the gels were 0.6–0.7 mmol/g and these resins were extremely stable to changes inpH.

     

Hydrophile Polymergele mit reaktiven Gruppen, 5. Mitt.: Chelatharze mit phosphorhaltigen Ankergruppen auf Basis von Saccharosemethacrylaten

Phosphorus containing chelating resins were synthesized by reaction of sucrosemethacrylate gels with various dialkylester halides of phosphoric acid and thiophosphoric acid. The sorption capacities of the hydrophilic gels were found to be max. 3.7 mmol/g and equilibrium was achieved within 5 minutes. The recycle of adsorption and elution was found to be satisfactory for Zn²⁺ and Cu²⁺ whereas only 50% of the bonded Hg²⁺ could be recovered reversibly.

     

Synthesis of a Dithiocarbamate Chelate Resin and Its Oxidized form and Their Adsorption Properties for Heavy Metal Ions

A series of macroporous dithiocarbamate chelate resins, III and V, and an oxidized resin, VI, with high adsorption capacity were prepared. The influence of various reaction conditions of amination, dithiocarboxylation, and oxidation were examined. The structure and the conversion of functional groups of resins were confirmed by IR spectra and elemental analysis. The adsorption capacities of Resin II for Hg²⁺, Cu²⁺, Zn²⁺, and Cd²⁺ are 4.40, 2.44, 1.77, and 1.36 mmol/g, respectively. The adsorption capacities of Resins V and VI for Cu²⁺. Zn²⁺, Ni²⁺, Co³⁺, Ag⁺, Hg²⁺, Cd²⁺, Pb²⁺, and Au³⁺ are 4.07–0.51 and 3.81–0.59 meq ion/g, respectively. The adsorption rate and the influence of pH on the adsorption percentage of the resins for metal ions were examined. Noble metal, transitional metal, and heavy metal ions can be quantitatively adsorbed by the resins. The adsorbed Cu²⁺, Pb²⁺, Cd²⁺, Co³⁺, and Ni²⁺ can be quantitatively eluted with 5N HNO₃, and the presence of large amounts of Ca²⁺, Mg²⁺, Fe³⁺, and Al³⁺ did not interfere.     

Abtrennung von Schwermetallionen mit Polystyrolaustauschern

Zusammenfassung Die Abtrennung von Cu²⁺, Fe³⁺, Hg²⁺, Au³⁺, Ag⁺, Pd²⁺ und UO ₂ ²⁺ aus Salzlösungen oder organischen Lösungsmitteln in Trennsäulen mit Hilfe von Polystyrolaustauschern, die Tiron, DMABR, TAM oder Glyoxal-bis (2-hydroxyanil) als Ankergruppen enthalten, wird beschrieben.

---

Separation of heavy metal ions with polystyrene exchangers

Summary The separation of Cu²⁺, Fe³⁺, Hg²⁺, Au³⁺, Ag⁺, Pd²⁺ and UO ₂ ²⁺ from salt solutions or organic solvents in separation columns by means of polystyrene exchangers containing Tiron, DMABR, TAM or glyoxal-bis(2-hydroxyanil) as anchor groups is described.

     

Preparation of crosslinked polystyrene-supported ethylenediamine via a S-containing spacer and adsorption properties towards metal ions

Two novel chelating resins were prepared by anchoring ethylenediamine to crosslinked polystyrene via a spacer containing sulfide. Their structures were characterized by Fourier transform-infrared spectra (FTIR) and scanning electron microscopy (SEM). Porous structure parameters of the resins were measured by ASAP 2020 using BET and BJH methods. Their adsorption capacities for several heavy metal ions especially Hg²⁺ were investigated. The results showed that for the two resins, the more N contents did not mean the better adsorption capacity and the saturated adsorption capacity of poly(2-ethylenediamidomercaptomethylstyrene) (PSM-EDA) for Hg²⁺ could reach to 3.0 mmol/g at room temperature. Isothermal adsorptions of the resins for Hg²⁺ could be described by Langmuir formula. The adsorption mechanism of the resins for Hg²⁺, Cu²⁺ and Ag⁺ was confirmed by X-ray photoelectron spectroscopy (XPS) and FTIR.     

Asymmetrische Hg(II)-Komplexe mit Organothiolato- bzw. Organoselenolato-und Triazenato-Liganden

The mixed mercury complexes (2XC₆H₄)₂N₃HgY (X=CH₃, F, Cl, Br, I;Y=SC₂H₅, SC₆H₅, SeC₆H₅) have been prepared. Both the Hg–S and Hg–Se bonds and, in contrast to other mixed triazenato-mercury compounds, the triazenato-mercury bonds have been shown to be kinetically labile on the NMR time scale by means of⁷⁷Se and¹⁹⁹Hg NMR spectroscopy. Evidence has been obtained for the presence of (2XC₆H₄)₂N₃HgY together with HgY ₂ and [(2XC₆H₄)₂N₃]₂Hg in solution.

     

聚乙烯苄多乙烯多胺二硫代羧酸大孔型螯合树脂合成与性质的研究

合成了具有高吸附容量的聚乙烯苄多乙烯多胺二硫代羧酸大孔型螫合树脂(DTC树脂)。探讨了胺化和二硫代羧化中各种反应条件的影响。制得的DTC树脂对Hg~(2+)、Cu~(2+)、Zn~(2+)、Cd~(2+)的吸附容量分别达4.40、2.44、1.77、1.36毫摩尔离子/克,在水中对微量的重金属离子在较宽pH范围内有良好的捕集效果。红外光谱、元素分析证实了合成过程中树脂功能基的转化。     

PREPARATION AND PROPERTIES OF MACRO-POROUS CHELATE RESINS OF CROSSLINKED POLYSTYRENE BEARING DITHIOCARBAMATE GROUPS

The title resins (DTC resins) with high adsorption capacity were prepared. The influences of various reaction conditions of amination and dithiocarboxylation were examined. The adsorption capacities of the produced DTC resin for Hg~(2 ), Cu~(2 ), Zn~(2 ) and Cd~(2 ) are 4.40, 2.44, 1.77 and 1.36 mmol/g, respectively. It is highly effective in collecting traces of heavy metal ions in water over a wide pH range. The conversion of the functional groups were confirmed by the IR-spectra and elementary. analysis.     

Preparation of macroreticular chelating resins containing mercapto groups from 2,3-epithiopropyl methacrylate/divinylbenzene copolymer beads and their adsorption capacity

Macroreticular chelating resins containing mercapto groups were prepared by the reaction of 2,3-epithiopropyl methacrylate/divinylbenzene macroreticular copolymer beads with ethanolic potassium hydrogensulfide solution for 1 h at 50°C. The adsorption capacities of this resin for Ag⁺, Hg²⁺, Pb²⁺ and Cd²⁺ were determined at various pH values. In the acidic region, the resin shows a high affinity for Ag⁺ and Hg²⁺ and high resistance against air oxidation. Cadmium is readily eluted with 1 mol dm^?3 hydrochloric acid; silver, mercury and copper ions can be eluted with 1 mol dm^?3 hydrochloric acid containing 5% (w/v) thiourea. The proposed resin appears to be useful for the removal of As³⁺ from aqueous solutions.     

Quantitative Trennung von Schwermetallen mit Chelataustauschern auf der Basis von Polystyrol

Zusammenfassung Die Trennung und Isolierung von folgenden Schwermetallen bei einem hohen Überschuß an Fremdionen mit Hilfe neuer selektiver Chelataustauscher wird beschrieben: Cu²⁺/Zn²⁺, Cu²⁺/Pb²⁺, Ag⁺/Cu²⁺, Ag⁺/Pb²⁺, Hg²⁺/Zn²⁺, Hg²⁺/Cd²⁺; Abtrennung von Hg²⁺. Unter gleichen Bedingungen war mit dem handelsüblichen Austauscher Dowex A-1 keine Trennung möglich.

---

Quantitative separation of heavy metals by means of chelating exchangers based on polystyrol

Summary The separation and isolation of the following heavy metals in presence of a high excess of foreign ions by means of new selective chelating exchangers is described: Cu²⁺/Zn²⁺, Cu²⁺/Pb²⁺, Ag⁺/Cu²⁺, Ag⁺/Pb²⁺, Hg²⁺/Zn²⁺, Hg²⁺/Cd²⁺; separation of Hg²⁺. Under the same conditions no separation could be achieved by the ion-exchanger Dowex A-1.

     

螯合树脂研究——Ⅺ.一类新的氨基二硫代甲酸型螯合树脂的合成及吸附性能

 本文报道了以多乙烯多胺为主链的巯基胺树脂与二硫化碳反应,合成了四种新型的氨基二硫代甲酸型螯合树脂,这类树脂对贵金属具有高的吸附容量和优良的吸附选择性。并通过红外光谱和X光电子能谱研究树脂及其金属螫合物。     

Abtrennung von toxischen Schwermetallen aus L?sungen mit chelatbildenden Celluloseaustauschern

Zusammenfassung Die Abtrennung von Spurenelementen (Hg, Cd, As, Mo, Cr) an drei Celluloseaustauschern mit chelatbildenden Ankergruppen wird beschrieben. An den Austauschern mit den Ankergruppen o-Aminothiophenol und Glyoxal-bis(2-mercaptoanil) werden hohe Verteilungskoeffizienten für Hg²⁺, Hg ₂ ²⁺ , CH₃Hg⁺ und Cd²⁺ gefunden, niedrigere für Arsenit und Arsenat; (CH₃)₂Hg wird nicht gebunden. Der mit Fe³⁺ beladene Hyphan-Austauscher weist hohe Verteilungskoeffizienten für Arsenat auf, etwas niedrigere für Arsenit, Chromat und Molybdat. In Trennsäulen werden die Kationen Hg²⁺ und Cd²⁺ und die Anionen Arsenat und Molybdat voneinander getrennt.

---

Separation of toxic heavy metals from solutions by means of chelating cellulose exchanges

Summary The separation of trace elements (Hg, Cd, As, Mo, Cr) on three cellulose exchangers with chelating anchor groups is described. On exchangers with the anchor groups o-aminothiophenol and glyoxal-bis(2-mercaptoanil) high distribution coefficients are found for Hg²⁺, Hg ₂ ²⁺ , CH₃Hg⁺ and Cd²⁺, lower ones for arsenite and arsenate; (CH₃)₂Hg is not bound. The exchanger Hyphan loaded with Fe³⁺ shows high distribution coefficients for arsenate, somewhat lower ones for arsenite, chromate and molybdate. In separation columns the cations Hg²⁺ and Cd²⁺ and the anions arsenate and molybdate are separated from each other.

---

---

Herrn Prof. Dr. H. Weisz zum 60. Geburtstag gewidmet     

Ein Beitrag zur Kristallchemie der Kobaltoxoniobate: CoNb2O6 mit Rutilstruktur

CoNb₂O₆ can be prepared by reaction of stoichiometric amounts of CoO (thermical decomposition of cobaltoxalate) and Nb₂O₅ in argon-atmosphere up to 1,400 °C. The isolated red-brown single crystals have tetragonal symmetry (a=472.6;c=305.4 pm; space group P4₂/mnm-D _4h ¹⁴ ). Electron probe micro-analysis of the single crystals verifies the composition Co_0.33Nb_0.67O₂. Co²⁺ and Nb⁵⁺ occupy statistically the metal positions of the rutil-type structure. The differences between Co_0.5Nb_0.5O₂ (CoNbO₄AlNbO₄-type) and Co_0.38Nb_0.67O₂ (CoNb₂O₆) are discussed.

     

A Simple Fluorometric Method Using Chlorophyll a for Determination of Hg2+ Ion

A simple and green analytical procedure based on chlorophyll a is presented for the determination of Hg²⁺ ion. Chlorophyll a was extracted and purified from the leaves of pea and is employed as a reagent for analysis of Hg²⁺ ion. It displays remarkable fluorescence emission at 674 nm when excited at 412 nm. The emission intensity decreased significantly on exposure to various concentrations of Hg²⁺ ion. This forms the basis for the determination of Hg²⁺ ion. The proposed method was evaluated for sensitivity and selectivity. The linear concentration range was found to be 2.0–10 μM with r² = 0.997 and the limit of detection for Hg²⁺ ion was 1.3 μM. Ions including Pb²⁺, Cd²⁺, Ag⁺, Zn²⁺, Co²⁺, Ni²⁺, Cu²⁺, Mg²⁺, Mn²⁺, Ru³⁺, Er³⁺, K⁺, Na⁺, NH₄⁺, Cl⁻, NO₃⁻, CH₃COO⁻ and SO₄²⁻ did not interfere with the measurement of Hg²⁺ ion even at 500-fold excess. Since chlorophyll a is widely available in the leaves of most plants, and the extraction and purification process is simple, this technique can provide an alternative, sensitive and economical way to determine Hg²⁺ ion.     

Mo3S132− Intercalated Layered Double Hydroxide: Highly Selective Removal of Heavy Metals and Simultaneous Reduction of Ag+ Ions to Metallic Ag0 Ribbons

We demonstrate a new material by intercalating Mo₃S₁₃^2? into Mg/Al layered double hydroxide (abbr. Mo₃S₁₃-LDH), exhibiting excellent capture capability for toxic Hg²⁺ and noble metal silver (Ag). The as-prepared Mo₃S₁₃-LDH displays ultra-high selectivity of Ag⁺, Hg²⁺ and Cu²⁺ in the presence of various competitive ions, with the order of Ag⁺>Hg²⁺>Cu²⁺>Pb²⁺≥Co²⁺, Ni²⁺, Zn²⁺, Cd²⁺. For Ag⁺ and Hg²⁺, extremely fast adsorption rates (≈90 % within 10 min, >99 % in 1 h) are observed. Much high selectivity is present for Ag⁺ and Cu²⁺, especially for trace amounts of Ag⁺ (≈1 ppm), achieving a large separation factor (SF_Ag/Cu) of ≈8000 at the large Cu/Ag ratio of 520. The overwhelming adsorption capacities for Ag⁺ (q_m^Ag=1073 mg g^?1) and Hg²⁺ (q_m^Hg=594 mg g^?1) place the Mo₃S₁₃-LDH at the top of performing sorbent materials. Most importantly, Mo₃S₁₃-LDH captures Ag⁺ via two paths: a) formation of Ag₂S due to Ag-S complexation and precipitation, and b) reduction of Ag⁺ to metallic silver (Ag⁰). The Mo₃S₁₃-LDH is a promising material to extract low-grade silver from copper-rich minerals and trap highly toxic Hg²⁺ from polluted water.     

Synthesis and metal-ion binding properties of new N2S4- and N2S5-donor macrocycles

Synthetic procedures for new N₂S₄- and N₂S₅-donor macrocycles (2 and 4) were given. The ligands were prepared by the reaction of NaBH₄ with the appropriate macrocyclic diamide in the presence of boron trifluoride ethyl etherate in dry tetrahydrofuran (THF). Solvent extraction method was used to evaluate metal-ion binding properties of the new ligands. The solvent extraction experiments suggested that the reduced macrocycles have Ag⁺ and Hg²⁺ selectivities compared to Pb²⁺, Co²⁺, Zn²⁺, Ni²⁺, Cu²⁺, Mn²⁺ and Cd²⁺ ions. The extraction constants (log K _ex) and complex compositions were determined for Ag⁺ and Hg²⁺ complex of compound (4).     

Preparation and adsorption properties of crosslinked polystyrene-supported low-generation diethanolamine-typed dendrimer for metal ions

Two novel chelating resins, polystyrene supported G1.0 diethanolamine-typed dendrimer (PS-DEA) and G2.0 diethanolamine-typed dendrimer (PS-(DEA)₂), were prepared by anchoring low-generations diethanolamine-typed dendrimer into crosslinked polystyrene in this paper. Fourier transform-infrared spectra (FTIR), scanning electron microscopy (SEM) and elemental analysis were employed to character their structures. The results of adsorption for metal ions showed that the resins had good adsorption capacities for Cu²⁺, Ag⁺ and Hg²⁺, especially PS-DEA for Cu²⁺. The adsorption kinetics and adsorption isotherms of PS-DEA for Cu²⁺ and PS-(DEA)₂ for Hg²⁺ were studied. The results showed that the adsorption kinetics of the two resins can be modeled by pseudo second-order rate equation wonderfully and Langmuir and Freundlich equations could well interpret the adsorption of PS-(DEA)₂ for Hg²⁺ and PS-DEA for Cu²⁺, respectively. The adsorption mechanism of the resins for Cu²⁺ was confirmed by X-ray photoelectron spectroscopy (XPS).     

Gravimetrische Bestimmung von Quecksilber(I) mit Kaliumhydrogen-o-Phthalat

Zusammenfassung Eine gravimetrische Methode zur Bestimmung von Quecksilber(I)-ionen mit Kaliumhydrogenphthalat wurde ausgearbeitet. Bei Konzentrationen von 0,1–0,2 g Hg^I/100 ml sind die Analysenergebnisse gut reproduzierbar. Die mittleren Abweichungen liegen zwischen –0,1 und –0,2%. Die Bestimmung wird durch Ag⁺, Pb²⁺, Hg²⁺, Bi³⁺, Fe³⁺ sowie Anionen, die mit Quecksilber(I) unlösliche Niederschläge bilden, gestört.

---

Summary A gravimetric method for the determination of mercury(I) ions by means of o-phthalate is described. For concentrations of 0.1 to 0.2 g Hg^I/100 ml well reproducible results are obtained. The mean deviations of the single determinations vary between –0.1 and –0.2%. Ag⁺, Pb²⁺, Hg²⁺, Bi³⁺, Fe³⁺ and anions forming sparingly soluble precipitates with mercurous ions interfere with the determination.

     

Production and properties of 3-cyanopyridine hydratase inRhodococcus equi SHB-121

A strain ofRhodococcus equi SHB-121 forming 3-cyanopyridine hydratase was screened from nitrile-polluted soil. The optimum conditions for the formation of 3-cyanopyridine hydratase by the strain SHB-121 have been studied. Under the optimum conditions, the specific activity of the enzyme reached 5.32 U/mg of dry cell, 95 times higher than that cultured in screening medium. In addition, the activity of coexistent amidase was very low. 3-Cyanopyridine hydratase was purified from methylacrylamide-induced cells ofRh. equi SHB-121 by procedures including ultrasonic oscillation, ammonium sulfate precipitation, and column chromatographies on DEAE-cellulose DE52, hydroxyapatite, and Sephadex G-25. The overall purification was 31-fold. The molecular weight of the enzyme was about 30 kDA by SDS-PAGE. The pI value was 4.1. The transition temperature and pH were 7.0°C and 6.0, respectively, resulting from the differential spectra. The optimum pH and temperature for the enzyme reaction were 8.0 and 30°C. The enzyme activity was strongly inhibited by Ag⁺, Hg²⁺, Cu²⁺, and NH₄ ⁺, whereas it was enhanced by Fe³⁺ slightly. The enzyme catalyzed the hydration of 3-cyanopyridine to nicotinamide, and itsKm value was 0.1 mol/L. Uncompetitive inhibitor sodium cyanide has a K, value of 5 mmol/L.