Synthesis and properties of a chelating resin containing triazolethiol groups

A macroreticular poly(acrylic acid)-based resin with triazolethiol as the functional group has been synthesized. The stability of the resin in acidic media and the behaviour in sorption and desorption of various metal ions have been investigated and compared with those of the acylthiosemicarbazide resin which is an intermediate in synthesis of the triazolethiol resin. Both resins show high affinity for copper(II) silver, cadmium and mercury(II), and high selectivity for silver and mercury(II) at low pH (1–2), and even at pH 7 if EDTA is present. The triazolethiol resin sorbs metal ions faster than the acylthiosemicarbazide resin does and sorbs mercury(II) from high concentrations of acids and neutral salt solutions. This resin has been applied to the concentration of silver and mercury(II) from sea-water samples by column operation.     

A chelate-forming resin bearing mercapto and azo groups and its application to the recovery of mercury(II)

A new chelate-forming resin bearing mercapto and azo groups was prepared from a common anion-exchange resin by treatment with azothiopyrine disulphonic acid (ATPS). ATPS resin was very stable and highly effective for the collection of mercury(II) by the batch and column methods. In the column method, the amount of mercury(II) in solution could be reduced to below 0.5 mug/l. The mercury(II) adsorbed could be eluted with thiourea solution, and the resin could be used repeatedly.     

Layer-by-layer self-assembly polytungstogermanate multilayer films and their photocatalytic properties under sunlight irradiation

Seven different types of thio- and/or amine-modified cellulose resin materials were synthesized and their mercury (II) ion adsorption properties determined. All seven resins showed good mercury (II) adsorption capability in the more neutral pH regions. However, the o-benzenedithiol- and o-aminothiophenol-modified cellulosic resins were found to be very effective in removing mercury (II) ions from strongly acidic media. For example, 93.5-100% mercury (II) ion recoveries from very acid aqueous solutions (nitric acid concentration ranged from 0.1 to 2.0 mol/L) were obtained using the o-benzenedithiol-modified resin while recoveries ranged from ca. 50% to 60% for the o-aminothiophenol-modified resin. An adsorption capacity of 23 mg (as Hg atoms) per gram of resin was observed for the o-benzenedithiol-modified cellulose in the presence of 1.0 mol/L nitric acid. This same resin shows very good selectivity for mercury (II) as only ruthenium (II) also somewhat adsorbed onto it out of 14 other metal ions studied (Ag(+), Al(3+), As(3+), Co(2+), Cd(2+), Cr(3+), Cu(2+), Fe(3+), Mn(2+), Ni(2+), Pt(2+), Pb(2+), Ru(2+), and Zn(2+)).     

碱金属和碱土金属离子在反相高效液相色谱柱上的保留机理

发现以酒石酸和吡啶二甲酸等羧酸水溶液作淋洗剂时，钠，铵，钾，镁和钙等碱金属及碱土金属离子在ＯＤＳ反相高效液相色谱柱上有明显的保留，而且相互之间能达到一定程度的分离。单独用分配或疏水作用等反相高效液相色谱的保留机理难以解释其保留行为。为此，作者提出了动态包固定相机理，即认为羧酸根阴离子因其疏水性在ＯＤＳ固定相有保留，在固定相表面形成具有羧酸基阳离子交换树脂功能的动态包覆固定相。     

Separation and concentration of molybdenum(VI) and tungsten(VI) with chelating ion-exchange resins containing sulphur ligands

Three chelating ion-exchange resins based on macroreticular polyacrylonitrile-divinylbenzene copolymers with thioglycollic acid and cysteine as functional groups have been tested for separation of molybdenum(VI) and tungsten(VI). On a short column of the thioglycollic acid resin, molybdenum(VI) and tungsten(VI) can be selectively sorbed from pH-4.3 acetate buffer and eluted with 2M hydrochloric acid and a mixture of 0.1M sodium hydroxide and 0.1M sodium chloride, respectively, with quantitative recovery even at very low concentrations. Simulated sea-water samples have been analysed.     

Bisphenol-A modified hyper-cross-linked polystyrene resin for salicylic acid removal from aqueous solution: adsorption equilibrium, kinetics and breakthrough studies

In this study, a series of bisphenol-A modified hyper-cross-linked polystyrene resins labeled as HJ-L00, HJ-L02, HJ-L04, HJ-L06 and HJ-L08 were synthesized, characterized and evaluated for adsorptive removal of salicylic acid from aqueous solutions. The structural characterization results indicated that the resins possessed predominant micropores/mesopores, moderate specific surface area and a few bisphenol-A groups on the surface. All the bisphenol-A modified hyper-cross-linked resins were effective for removing salicylic acid from aqueous solutions, and sample HJ-L02 had the largest adsorption capacity. The adsorption equilibrium data were correlated by the Freundlich isotherm model, and a positive adsorption enthalpy was obtained. The kinetic data were analyzed with two diffusion models and indicated that the intra-particle diffusion was the sole rate-controlling step in the first stage. The dynamic experimental results showed that the breakthrough point of the HJ-L02 adsorbent was at 90.2 BV (bed volume, 1 BV=10 mL) for a feed concentration of 500.0mg/L of salicylic acid, and 14.0 BV of 1% of sodium hydroxide could completely regenerate the HJ-L02 adsorbent column.     

Succinic acid adsorption from fermentation broth and regeneration

More than 25 sorbents were tested for uptake of succinic acid from aqueous solutions. The best resins were then tested for successive loading and regeneration using hotwater. The key desired properties for an ideal sorbent are high capacity, complete stable regenerability, and specificity for the product. The best resins have a stable capacity of about 0.06 g of succinic acid/g of resin at moderate concentrations (1–5 g/L) of succinic acid. Several sorbents were tested more exhaustively for uptake of succinic acid and for successive loading and regeneration using hot water. One resin, XUS 40285, has a good stable isotherm capacity, prefers succinate over glucose, and has good capacities at both acidic and neutral pH. Succinic acid was removed from simulated media containing salts, succinic acid, acetic acid, and sugar using a packed column of sorbent resin, XUS 40285. The fermentation byproduct, acetate, was completely separated from succinate. A simple hot water regeneration successfully concentrated succinate from 10 g/L (inlet) to 40–110 g/L in the effluent. If successful, this would lower separation costs by reducing the need for chemicals for the initial purification step. Despie promising initial results of good capacity (0.06 g of succinic/g of sorbent), 70% recovery using hot water, and a recovered concentration of >100 g/L, this regeneration was not stable over 10 cycles in the column. Alternative regeneration schemes using acid and base were examined. Two (XUS 40285 and XFS-40422) showed both good stable capacities for succinic acid over 10 cycles and >95% recovery in a batch operation using a modified extraction procedure combining acid and hot water washes. These resins showed comparable results with actual broth.     

Determination of trace lead, cadmium and mercury by on-line column enrichment followed by RP-HPLC as metal-tetra-(4-bromophenyl)-porphyrin chelates

This paper reports the utilization of tetra-(4-bromophenyl)-porphyrin (T(4)BPP) as a chelating reagent using Waters Xterratrade mark RP(18) column for the on-line column enrichment and the separation of trace lead, cadmium and mercury ions by reversed-phase high-performance liquid chromatography (RP-HPLC) with photodiode array detector. When the Hg-T(4)BPP, Pb-T(4)BPP and Cd-T(4)BPP chelates were injected into the injector and sent to the enrichment column with 0.05 mol l(-1) of pH 10.0 pyrrolidine-phosphoric acid buffer solution (containing 10% of tetrahydrofuran (THF)) as mobile phase. The chelates were retained on the top of the enrichment column. After the enrichment is finished, by switching the valve of six-ports switching valve, the retained metal-T(4)BPP chelates will be eluted by mobile phase in reverse direction and will travel towards analytical column. With THF (containing 0.05 mol l(-1), pH 10.0 pyrrolidine-phosphoric acid buffer salt) and 0.05 mol l(-1), pH 10.0 pyrrolidine-phosphoric acid buffer solution (containinging 10% THF) gradient elution as mobile phase, the chelates separation on the analytical column was satisfactory. The linearity ranges are 0.01-120 mug l(-1) for each metal ion. The detection limits (S/N=3) of lead, cadmium and mercury are 1.0, 0.5 and 1.0 ng l(-1), respectively. This method can be applied to the determination (mug l(-1)) level of lead, cadmium and mercury in drinking water with satisfactory results.     

Adsorption behaviour of metal ions on hydroximate resins

Some new chelating ion-exchange resins containing a hydroxamic acid moiety attached to a divinylbenzene styrene (DVBS) copolymer, i.e. glycine hydroximate in DVBS (GH-DVBS). anthranilic acid hydroximate in DVBS (AAHDVBS), malonic acid dihydroximate in DVBS (MAH-DVBS) and iminodiacetic acid dihydroximate in DVBS (IDAAH-DVBS). have been synthesized and their various physicochemical characteristics studied. The degree of retention of metal ions by the resins at equilibrium has been determined in terms of the molar distribution coefficient (k(d)). In general, the resins having a dihydroximate moiety are found to be more efficient compared to monohydroximate resins. However, it is of interest to note that the monohydroximate derivative of amino acid (GH-DVBS) showed better metal retention capability than the dihydroximate of carboxylic acid (MAH-DVBS). The selectivity of the resins for transition and highly charged metal ions is quite high compared to that for alkaline earth metals. All the synthesized resins can be utilized for the separation of a mixture of metal ions because the differences in the distribution coefficient values are large enough to permit good separations on columns. However, the GH-DVBS resin was tried for the separation of copper cobalt and copper nickel mixtures at pH 5.5 using the column mode of operation.     

聚甲基丙烯酰胺型配体交换色谱载体的研究

通过交联聚甲基丙烯酸甲酯与过量的乙二胺或多乙烯多胺反应,然后再与氯乙酸反应得到含有α-胺基乙酸基团的亲水性的聚甲基丙烯酰胺树脂.用这些树脂的Cu~(2+)络合物作为色谱载体对中性氨基酸进行分离.研究了色谱条件如洗脱剂组成、流速和柱温对分离的影响.     

Selection of anion exchangers for detoxification of dilute-acid hydrolysates from spruce

Six anion-exchange resins with different properties were compared with respect to detoxification of a dilute-acid hydrolysate of spruce prior to ethanolic fermentation with Saccharomyces cerevisiae. The six resins encompassed strong and weak functional groups as well as styrene-, phenol-, and acrylic-based matrices. In an analytical experimental series, fractions from columns packed with the different resins were analyzed regarding pH, glucose, furfural, hydroxymethylfurfural, phenolic compounds, levulinic acid, acetic acid, formic acid, and sulfate. An initial adsorption of glucose occurred in the strong alkaline environment and led to glucose accumulation at a later stage. Acetic and levulinic acid passed through the column before formic acid, whereas sulfate had the strongest affinity. In a preparative experimental series, one fraction from each of six columns packed with the different resins was collected for assay of the fermentability and analysis of glucose, mannose, and fermentation inhibitors. The fractions collected from strong anion-exchange resins with styrene-based matrices displayed the best fermentability: a sevenfold enhancement of ethanol productivity compared with untreated hydrolysate. Fractions from a strong anion exchanger with acrylic-based matrix and a weak exchanger with phenol-based resin displayed an intermediate improvement in fermentability, a four- to fivefold increase in ethanol productivity. The fractions from two weak exchangers with styrene- and acrylic-based matrices displayed a twofold increase in ethanol productivity. Phenolic compounds were more efficiently removed by resins with styrene-and phenol-based matrices than by resins with acrylic-based matrices.     

The application of macroporous resins in the separation of licorice flavonoids and glycyrrhizic acid

Glycyrrhizic acid (GA) and licorice flavonoids (LF) are the two classes of bioactive components in licorice with known pharmacological effects. But long-term excessive intake of GA may cause sodium retention and hypertension. In this study, the performance and adsorption characteristics of four widely used macroporous resins for the separation of deglycyrrhizinated, flavonoids enriched licorice has been critically evaluated. The sorption and desorption properties of LF and GA on macroporous resins including XDA-1, LSA-10, D101 and LSA-20 have been compared. The adsorption capacity was found to depend strongly on the pH of the feed solution. XDA-1 offers much higher adsorption capacity for GA and LF than other resins, and its adsorption data fit the best to the Freundlich isotherm. XDA-1 also shows much higher adsorption affinity towards LF than that of GA based on calculated results from the measured adsorption isotherms. Dynamic adsorption and desorption experiments have been carried out on a XDA-1 resin packed column to obtain optimal parameters for separating GA and LF. An enriched LF extract (about 21.9% purity) free of GA, and an enriched GA extract with 66% purity can be separated from crude licorice extract in one run.     

含有多甘醇、多甘醇单醚功能基的树脂的合成及其对贵金属离子的吸附性

合成了六种含有乙二醇、多甘醇及多甘醇单醚功能基的树脂。树脂的功能基转化率达93.4—97.5％。树脂2—6对Au(Ⅲ)的吸附率达90—100％,对Pt(Ⅳ)为40—50％,但对共存的Pd(Ⅱ)、Cu~(2+)、Ni(2+)、Cd(2+)等离子甚少吸附。六种树脂的吸金容量在226.3—93.8mg Au(Ⅲ)/g树脂之间。被吸附的金可用3％。硫脲-1N盐酸容液洗脱。洗脱率达95.8％以上。     

Synthesis and efficiency of a spherical macroporous epoxy-polyamide chelating resin for preconcentrating and separating trace noble metal ions

The determination of noble metals in various materials usually requires their preconcentration and separation from other elements. In spite of the improvements in analytical instrumentation and the development of new analytical techniques such as ICP-MS, which are capable of detecting metal ions at ppt levels, the interference caused by the sample matrix still exists and is perhaps the most serious problem, making a pre-determination enrichment step necessary. Thus, the search for efficient preconcentration and separation methods is essential. A series of chelating resins that can selectively adsorb noble metal ions from aqueous solutions have been described. Functional groups, such as salicylaldoxime and thiosemicarbazide have been incorporated in cross-linked polymers or porous silica gel. These resins have very high selectivity for one or several types of noble metal ion. However, desorption of noble metals from these resins is usually difficult. Hence, the development of an adsorbent from which noble metals can be easily desorbed is needed. In this paper, a new spherical macroporous epoxy-polyamide chelating resin that met this requirement was synthesized by one step reaction. The synthesis of the resin was safe, rapid and more simple and economical than many report adsorbents. Meanwhile, the resin showed more advantages: better acid and alkali resistance; higher adsorption capacity and lower preconcentration concentrations. A resin column procedure combined with inductively coupled plasma atomic emission spectrometry (ICP-AES) for the determination of trace Rh(III), Ru(III) and Ir(IV) in real samples was established.     

Chelating ion-exchangers containing n-substituted hydroxylamine functional groups : Part II. N-acylphenylhydroxylamines

The problems associated with the conversion of commercial carboxylic acid ion exchangers to the acid chloride have been studied and a synthesis of a cross-linked poly(acryloyl chloride) is described. Reaction with phenylhydroxylamine produced a chelating ion exchanger, possessing acyl oxime functional groups, whose properties are compared with those of an aroyl oxime exchanger described earlier. Resin capacity from the acyl oxime group was 0.45 mmole g^-1, and the resin had a rapid equilibration rate. A column separation of mercury and lead is discussed.     

Influence of medium polarity upon selectivity and efficiency of alkali metal cation sorption by polyether carboxylic acid resins

The influence of medium polarity upon competitive sorption of alkali-metal cations from aqueous and aqueous methanolic solutions by the polymethacrylic acid resin Amberlite CG-50, two acyclic polyether carboxylic acid resins, and six sym-(alkyl)dibenzo-16-crown-5-oxyacetic acid resins has been investigated. Addition of methanol was found to strongly depress the selective Li(+) sorption of CG-50 and one of the acyclic polyether carboxylic acid resins. Enhancement of metal ion-crown ether interactions as the percentage of methanol in the medium was increased accentuates the Na(+) sorption selectivity for the lariat ether carboxylic acid resins. The highest Na(+) sorption selectivity was obtained for sym-(alkyl)-dibenzo-16-crown-5-oxyacetic acid resins with ethyl and propyl groups in 80% methanol-20% water.     

Synthesis and metal ion uptake studies of chelating resins derived from formaldehyde-furfuraldehyde condensed phenolic Schiff bases of 4,4'-diaminodiphenylether and o-hydroxyacetophenone

Two new chelating resins (o-HAP-DDE-HCHO and o-HAP-DDE-FFD), having multiple functional groups are synthesised by condensing the Schiff base of o-hydroxyacetophenone-4,4′-diaminodiphenylether (o-HAP-DDE) with formaldehyde and furfuraldehyde, respectively. The extent of loading of metal ions Cu(II) and Ni(II) was studied in both competitive and non-competitive conditions varying the time of contact, metal ion concentration and the pH of the reaction medium. Both the resins are able to preferentially remove Cu(II) from the mixture of Cu(II) and Ni(II) at a pH 5.89 in the batch operation, maximum % uptake being 76.8 and 84.1, respectively, for o-HAP-DDE-HCHO and o-HAP-DDE-FFD. The furfuraldehyde condensed resin was found to be more effective in removing Cu(II) ions than the formaldehyde condensed resins in batch technique. The resins exhibited little affinity for alkali and alkaline earth metal ions. Further, the furfuraldehyde condensed resin was utilised in column operation for removing Cu(II) ions. Elution study with HCl (>1.0 mol l⁻¹) resulted in removal of nearly 40–50% of loaded Cu(II) from the resin column.     

Determination of copper at ng levels by in-line preconcentration and flow-injection analysis coupled with flame atomic-absorption spectrometry

Oxine/formaldehyde/resorcinol and oxine/formaldehyde/hydroquinone resins have been synthesized and their physicochemical properties studied. Conditions were optimized for the preconcentration of copper by batch extraction and column chromatography with the resins. A flow-injection analysis (FIA) manifold was constructed for the determination of copper at ng levels by preconcentration on microcolumns containing the resins, stripping, and atomic-absorption spectrometry. For batch preconcentration a pH of about 2.5-3 was optimal whereas in the FIA system a broader pH range (approximately 2-3.5) could be used. Separations of binary mixtures of Cu(II) with Ni(II) or PB(II) at microg/ml level did not show any cross-contamination. In the FIA, a 2 cm long column and 2 ml/min flow-rate were adequate for quantitative uptake of copper; 50 micro1 of 0.1M hydrochloric acid quantitatively eluted the copper.     

Preparation of polymer resin and inorganic oxide supported peroxy-acids and their use in the oxidation of tetrahydrothiophene

Peroxy-benzoic acid residues have been attached to polystyrene resins with nominal crosslink ratios of 5–40%, and also to various commercially available silicas and aluminas. Chemical modification of the resins becomes increasingly difficult as the crosslink ratio is increased, although resistance to oxidative degradation by hydrogen peroxide in methanesulphonic acid is simultaneously enhanced. Two different linkages were employed for the binding of peroxy-acid groups to the inorganic oxide supports, one involving a direct silicon aromatic bond and the other with an ethylene bridge interposed. In both cases, the introduction of peroxy-acid groups proceeded with ease and without any apparent degradation although the loadings achieved were somewhat lower than with the resins, as anticipated. All the supported peroxyacids functioned as oxidants for tetrahydrothiophene, the 5% crosslinked species being the most effective of the resin bound acids. One macroreticular resin displayed partial selectivity in oxidizing the thioether to its sulphoxide rather than sulphone. The best of the inorganic oxide supported oxidants approached closely to the reactivity shown by the 5% crosslinked resin; a mixed silica/alumina support showed the highest selectivity for sulphoxide formation in the case when its bound peroxy-acid was attached by a direct silicon aromatic bond.     

STUDY ON THE SYNTHESIS AND STRUCTURE OF MACRORETICULAR BEAD PAN/PVC IPN RESINS

Macroreticular bead PAN/PVC IPN resins with cyano and chloro groups were synthesized by interpenetrating polymerization of acrylonitrile, or acrylonitrile and divinylbenzene into a macroporous polyvinyl chloride bead. The composition and structure of the bead IPN resins have been investigated by means of FT-IR, NMR, SEM, mercury porosimetry and elemental analysis. During the process of interpenetrating polymerization, the chain propagation obeys Bernoullian statistical law, and no grafting polymerization has been observed. The content of cyano group in the resulting IPN resins can be adjusted by the amount of acrylonitrile added. The morphology of the IPN resins basically resembles that of the polyvinyl chloride bead, whereas the pore structures vary to a certain degree