Efficiency and mechanism of new poly(acryl-phenylamidrazone phenylhydrazide) chelating fiber for adsorbing trace Ga, In, Bi, V and Ti from solution

A new po1y(acrylphenylamidrazone phenylhydrazide) chelating fiber is synthesized from polyacrylonitrile fiber and used for preconcentration and separation of trace Ga(III), In(III), Bi(III), V(V) and Ti(IV) from solution (5–50 ng ml⁻¹ Ti(IV) or V(V) and 50–500 ng ml⁻¹ Ga(III), In (III) or Bi(III) in 1000–100 ml of solution can be enriched quantitatively by 0.15 g of fiber at a 4 ml min⁻¹ flow rate in the pH range 5–7 with recoveries >95%). These ions can be desorbed quantitatively with 20 ml of 4 M hydrochloric acid at 2 ml min⁻¹ from the fiber column. When the fiber which had been treated with concentrated hydrochloric acid and washed with distilled water until neutral was reused eight times, the recoveries of the above ions by enrichment were still >95%. Two-hundred-fold to 10 000-fold excesses of Cu(II), Zn(II), Ca(II), Mn(II), Cr(III), Fe(III), Ba(II) and Al(III) caused little interference in the determination of these ions by inductively coupled plasma-atomic emission spectrometers (ICP-AES). The relative standard deviations for enrichment and determination of 50 ng ml⁻¹ Ga, In or Bi and 10 ng ml⁻¹ V or Ti are in the range 1.2–2.7%. The contents of these ions in real solution samples determined by this method were in agreement with the certified values of the samples with average errors <3.7%.     

Properties and applications of polyacrylacylisothiourea chelating fiber for preconcentration and separation of trace titanium, vanadium and bismuth

An ICP-OES method using a new poly-acrylacylisothiourea chelating fiber to preconcentrate and separate trace Ti(IV), V(V) and Bi(III) ions from solution samples is established. The results show that 5–25 ng/ml of Ti or V and 50–250 ng/ml of Bi ions in 200–1000 ml of solution can be enriched quantitatively by 0.05 g of the fiber at pH 3 with recoveries over 97%. These ions can be desorbed quantitatively with 10 ml of 4M HC1O₄. 100- to 1000-fold excesses of Fe(III), Al(III), Ca(II), Mg(II), Cu(II), Ni(II) and Mn(II) ions cause little interference. The chelating fiber stored for about 2 years can still be used repeatedly for preconcentration and separation of trace Ti, V and Bi ions from solution with above 95% recovery. The RSDs for enrichment and determination of 5 ng/ml of Ti or V and 50 ng/ml of Bi are in the range 2.5–2.8%. The recoveries of added standard in real waste waters and mineral samples are between 96 and 100%, and the concentration found for each ion in the mineral sample was in good agreement with that measured by ETAAS.     

Synthesis and Efficiency of an Epoxy-Urea Chelating Resin for Preconcentrating and Separating Trace Bi,In, Sn,Zr, V And Ti From Solution Samples

Abstract

A new epoxy-urea chelating resin was synthesized from epoxy resin and used for the preconcentration and separation of trace Bi(III), In(III), Sn(IV), Zr(IV), V(V) and Ti(IV) ions from solution samples. The analyzed ions can be enriched at pH 5 at a flow rate of 1–4 ml/min, and can be also desorbed with 10 mL of 2 M HCl +0.1g NH₄F solution from the resin column, with recoveries over 97%. The chelating resin reused 6 times can still adsorb quantitatively the Bi, In, Sn, Zr, V and Ti ions, and eighty to thousand-fold excesses of Ca(II), Mg(II), Cu(II), Zn(II), Al(III), Sb(III), Ni(II), Mn(II) and Fe(III) cause little interference with the enrichment and determination of these ions. The RSDs of the proposed method for the determination of 500–50 ng/ml Bi, In and Sn, 50–5.0 ng/ml Zr, V and Ti were in the range of 0.4 ～ 4.0%, the enrichment factor of the resin for the ions is in the range of 10–100. The recoveries of added standard in waste water are between 96% and 100%, and the concentration of each ion in alloy steel sample determined by the method is in good agreement with the reference value analyzed by a steel plant with average error <2.8%.     

Synthesis of spherical macroporous epoxy-dicyandiamide chelating resin and properties of concentration and separation of trace metal ions from samples

A novel spherical macroporous epoxy-dicyandiamide chelating resin is synthesized simply and rapidly from epoxy resin and use for the preconcentration and separation of trace Ga(III), In(III), Bi(III), Sn(IV), Pb(II), V(V) and Ti(IV) ions from solution samples. The analyzed ions can be quantitatively concentrated by the resin at flow rate of 3.0 ml min(-1) at pH 3, and can also be desorbed with 10 ml of 4 M HCl+0.2 g thiourea from the resin column with recoveries of 97-100%. The chelating resin is reused for eight times, the recoveries of these ions are still over 92%, and a 100-1000 times of excess of Fe(III), Al(III),Ca(II), Mg(III), Ni(II), Mn(II), Co(II), Cu(II), Zn(II), and Cd(II) cause no interference in the determination of these ions by inductively-coupled plasma atomic emission spectrometry. The capacities of the resin for the analytes are in the range of 0.66-4.20 mmol g(-1). The results show the relative standard deviation for the determination of 50.0 ng ml(-1) Ga(III), In(III), Bi(III), Sn(IV) and Pb(II), 5.0 ng ml(-1) V(V) and Ti(IV) are in the range of 1.2-4.0%. The recoveries of a standard added in real solution samples are between 96 and 100%, and the concentration of each ion in mineral sample detected by the method is in good agreement with the certified value.     

Efficiency of a new poly(acrylamidrazone-hydrazide lacmoid) chelating fibre for preconcentrating and separating traces of chromium, gallium, indium and titanium from solutions

A new poly(acrylamidrazone-hydrazide lacmoid) chelating fibre has been synthesized from polyacrylonitrile fibre and used for the preconcentration and separation of traces of Cr(III), Ga(III), In(III) and Ti(IV) from solutions with satisfactory results. These ions can quantitatively be enriched by the chelating fibre at a flowrate of 6 ml/min at pH 6, and quantitatively desorbed with 10 ml of eluent at a rate of 4 ml/min. The chelating fibre reused ten times can still quantitatively concentrate traces of the above ions; twenty to two hundred-fold excesses of coexistent ions caused only little interference. With concentrations of 10 ng/ml Cr(III) and Ti(IV), and 50 ng/ml Ga(III) and In(III), the RSD was in the range of 1.4–4.6%. The contents determined in real samples were generally in agreement with the results obtained by HG-AAS; the recoveries of added standards were >96%.     

Ion flotation behaviour of thirty-one metal ions in mixed hydrochloric/nitric acid solutions

The ion flotation of 31 metal ions in hydrochloric/nitric acid solution with the cationic surfactant cetylpyridinium chloride was investigated. A 25-ml portion of 0.27-2.87 x 10(-4)M metal ion and 1.8-6.0 x 10(-4)M cetylpyridinium chloride solution in 0.17-3.4M acid mixture ([HCl]:[HNO(3)] = 2.4:1) was subjected to flotation in a cell, 22.5 cm high and 4.0 cm in diameter, for 5 min, with nitrogen bubbles. Ir(IV), Pt(IV), Ge(IV), Sn(IV), Bi(III), Au(III), Tl(III), Pd(II) and Sn(II) were floated from solution in 95-100% yield; Ru(III), Rh(III), Ir(III), Hg(II), Ag(I) and Tl(I) were partly floated, while Cr(VI), Ti(IV), Zr(IV), Ga(III), In(III), Fe(III), Sb(III), Al(III), Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), CD(II) and Pb(II) were floated with less than 20% yield. The flotation behaviour of these metal ions in the mixed acid system was compared with that in hydrochloric acid. The flotation is more efficient in the mixed acid system.     

Efficiency and application of poly(acryldinitrophenylamidrazone-dinitroacrylphenylhydrazine) chelating fiber for pre-concentrating and separating trace Au(III), Ru(III), In(III), Bi(III), Zr(IV), V(V), Ga(III) and Ti(IV) from solution samples

Poly(acryldinitrophenylamidrazone-dinitroacrylphenylhydrazine) chelating fiber was synthesized from polyacrylonitrile fiber and used for enrichment and separation for traces of Au(III), Ru(III), In(III), Bi(III), Zr(IV), V(V), Ga(III) and Ti(IV) ions from solution samples. The acidity, rate, re-use, capacity and interference on the adsorption of ions on the chelating fiber as well as the conditions of desorption of these ions from the chelating fiber were investigated by means of inductively coupled plasma optical emission spectrometry. The results show that 10-100 ngml(-1) of Au(III), Ru(III), In(III), Bi(III), Zr(IV), V(V), Ga(III) and Ti(IV) ions can be quantitatively enriched by the chelating fiber at a 2 mlmin(-1) of flow rate in the range pH 4-5, and desorbed quantitatively with 20 ml of 5 M HCl for In(III), Bi(III), Zr(IV), V(V), Ga(III), Ti(IV) and 20 ml of 4 M HCl+2% CS(NH(2))(2) solution for Au(III), Ru(III) (with recovery>95%). 50- to 500- fold excesses of Fe(III), Al(III), Mg(II), Mn(II), Ca(II), Cu(II), Ni(II) ions cause little interference in the concentration and determination of analyzed ions. When the fiber was reused for 8 times, the recoveries of the above ions enriched by the fiber were still over 87%. The relative standard deviations (RSDs) for the enrichment and determination of 10 ngml(-1) Au, Ru, In, Bi, Ga and 1 ngml(-1) Zr, V, Ti were lower than 3.0%. The results obtained for these ions in real solution samples by this method were basically in agreement with the given values with average errors of less than 6.3%. FT-IR spectra show that existence of NNCNHNH, OCNHNH and NO(2) functional groups are verified in chelating fiber, and Au(III) or Ru(III) is mainly combined with nitrogen (or oxygen) of the groups to form a chelate complex.     

Synthesis and efficiency of poly(acrylamidrazonehydrazide) chelating fiber for preconcentrating and separating trace gold and palladium from solution

A new poly(acrylamidrazone-hydrazide) chelating fiber has been synthesized using polyacrylonitrile fiber as a starting material. An ICP-OES method for applying the fiber to preconcentrate and separate trace Au(III) and Pd(IV) ions in solution has been established. The experiments show that 8 ng/ml Au(III) and 6 ng/ml Pd(IV) in 1000 ml of solution can be enriched quantitatively by the fiber column at a flow rate of 12 ml/min at pH 2. These ions can be desorbed quantitatively with 10 ml of 2.5% CS(NH₂)₂ + 6% H₂SO₄ containing 0.2% Fe(II) from the column at an elution rate of 6 ml/min. A fiber treated with 12M HCl or 15M HNO₃ can be re-used 10 times with above 95% recoveries of Au(III) and Pd(IV), and 120–800-fold excesses of Cu(II), Mn(II), Fe(III), Al(III), Ni(II), Mg(II) and Ca(II) ions cause little interference. The RSDs are 2.0% for 8 ng/ml Au and 3.5% for 6 ng/ml Pd. The recovery of added standard in a solution sample from a metal smelter is 96.2% for Au and 100% for Pd, and the content of each ion in the sample determined by the method is in agreement with the analysed value from the smelter laboratory.     

Synthesis of poly(N-aminoethyl)acrylamide chelating fiber and properties of concentration and separation of noble metal ions from samples

A new kind of poly(N-aminoethyl)acrylamide chelating fiber was synthesized from nitrilon (an acrylonitrile-based synthetic fiber) and used for the concentration and separation of traces of noble metal ions from solution. The results showed that 16-80 ng ml (1) of Au(III), Pt(IV), Pd(IV), Ir(IV), Ru(III) and Rh(III) can be quantitatively concentrated by the fiber up to a flow rate of 20 ml min (-1) at pH 3, and can be desorbed quantitatively with an eluting agent from the fiber column with recoveries of 96-100%. For a fiber reused 10 times, the recoveries of these ions were still over 94%, and a 100-1000 times excess of Fe(III), Al(III), Ca(II), Mg(II), Ni(II), Co(II), Cu(II) and Zn(II) caused no interference in the determination of these ions by inductively-coupled plasma atomic emission spectrometry. The capacities of the fiber for the analytes were in the range 0.80-2.62 mol g(-1), The relative standard deviation of the method was between 0.02% and 2.6%. Recoveries of a standard added to a real sample were 96.8-99.2%. The average error for the analysis by this method for a powder sample was 3.5%. The IR spectra of the analyte-bearing fiber showed that these ions coordinated to nitrogen sites in the fiber.     

Synthesis and Applications of Poly(Acrylphenylamidrazone-Phenyl-Hydrazide-Acylphenylhydrazine) Chelating Fiber for Preconcentration and Separation of Trae In(III), Zr(IV), Tl(I), V(V), Ga(III) and Ti(IV) from Solution Samples

 An ICP-OES method using a new poly (acrylphenylamidrazone-phenylhydrazide-acylphenylhydrazine) chelating fiber to preconcentrate and separate trace In(III), Zr(IV), Tl(I), V(V), Ga(III) and Ti(IV) ions from solution samples has been established. The new chelating fiber was synthesized using polyacrylonitrile fiber as a starting material and the structure of the chelating fiber was determined by FT infrared spectrometry. The acidity, adsorption rate, re-use, capacity and interference on the adsorption of ions on the chelating fiber as well as the conditions of desorption of these ions from the chelating fiber were investigated by means of inductively coupled plasma optical emission spectrometry (ICP-OES). The results show that the relative standard deviations for the determination of 10 ng/ml In, Tl, Ga and 1 ng/ml Zr, V, Ti were lower than 2.5%. The results obtained for these ions in real solution samples by this method were basically in agreement with the given values with average errors of less than 4%. Received November 29, 2000. Revision May 22, 2001.     

Selective and quantitative separation of zinc and lead from other elements by cation-exchange chromatography in hydrohalic acid-acetone solutions

Zinc and lead can be separated from Cd, Bi(III), In and V(V) by eluting these elements with 0.2M hydrochloric acid in 60% acetone from a column of AG50W-X8 cation-exchange resin, zinc and lead being retained. Mercury(II), Tl(III), As(III), Au(III), Sn(IV), Mo(VI), W(VI) and the platinum metals have not been investigated quantitatively, but from their distribution coefficients, should also be eluted. Vanadium(V), Mo(VI) and W(VI) require the presence of hydrogen peroxide. Zinc and lead can be eluted with 0.5M hydrochloric acid in 60% acetone or 0.5M hydrobromic acid in 65% acetone and determined by AAS; the alkali and alkaline-earth metal ions, Mn(II), Co, Ni, Cu(II), Fe(III), Al, Ga, Cr(III), Ti(IV), Zr, Hf, Th, Sc, Y, La and the lanthanides are retained on the column, except for a small fraction of copper eluted with zinc and lead. Separations are sharp and quantitative. The method has successfully been applied to determination of zinc and lead in three silicate rocks and a sediment.     

Synthesis of polyacrylaminoimidazole chelating fiber and properties of concentration and separation of trace Au, Hg and Pd from samples

A novel polyacrylaminoimidazole chelating fiber is synthesized simply and rapidly from nitrilon (an acrylonitrile-based synthetic fiber) and used for the preconcentration and separation of trace Au(III), Hg(II) and Pd(IV) ions from solution samples. The analyzed ions can be quantitatively concentrated by the fiber up to a flow rate of 15.0 mlmin(-1) at pH 3 and can also be desorbed with 15 ml of 4 M HCl+3% thiourea from the fiber column, with recoveries of 96.5-100%. The chelating fiber is reused ten times; the recoveries of these ions are still over 92%, and 100-1000 times of excess of Fe(III), Al(III), Ca(II), Mg(II), Ni(II), Mn(II), Cu(II), Zn(II) and Cd(II) causes no interference in the determination of these ions by inductively coupled plasma atomic emission spectrometry. The capacities of the fiber for the analytes are in the range of 1.56-2.92 mmolg(-1). The results show that the relative standard deviations for the determination of 50.0 ngml(-1) each of Au(III), Hg(IV) and Pd(IV) are in the range of 0.7-2.1%. The recoveries of a standard added in real solution samples are between 97 and 99%, and the concentration of each ion in powder sample detected by the method is in good agreement with the certified value.     

Synthesis of Polyacrylaminothiourea Chelating Fiber and Properties of Concentration and Separation of Trace Noble Metal Ions from Samples

A novel polyacrylaminothiourea chelating fiber was synthesized simply and rapidly from nitrilon (an acrylonitrile-based synthetic fiber), which was applied to preconcentrate and separate of trace amount of Au(Ⅲ）,Pt(Ⅳ）,Pd(Ⅳ） and Ir (Ⅳ） ions from solution of samples.The analyzed ions can be quantitatively concentrated by the fiber up to a flow rate of 20.0mL/min at pH2, and can also be desorbed with 15 mL of 4mol/L HCl 3% thiourea from the fiber column with recoveries of 96.5%-100%.The chelating fiber can be reused for ten times,the recoveries of these ions are still over 92%,and hundred to thousand times of excess of Fe(Ⅲ）,Al（Ⅲ）,Ca(Ⅱ），Mg（Ⅱ）,Ni(Ⅱ）,Mn（Ⅱ),Cu(Ⅱ），Zn(Ⅱ），and Cd(Ⅱ） cause no interference on the determination of the analyzed ions by inductively-coupled plasma atomic emission spectrometry (ICP-AES).The static saturation adsorption capacities of the fiber for the analytes are in the range of 1.15-2.80mmol/g.The relative standard deviations for the determination of 20.0ng/mL each of Au(Ⅲ）,Pt(Ⅳ）,Pd(Ⅳ）and Ir(Ⅳ） are in the range of 0.7%-3.0%.The recoveries for test from standard additions to real solution samples are between 96% and 100%.The concentration of each ion in powder sample detected by the method is in good agreement with the certified value.     

Synthesis and efficiency of a spherical macroporous epoxy-melamine chelating resin for preconcentrating trace elements from solutions

A new spherical macroporous epoxy-melamine chelating resin was synthesized simply and rapidly and used for the preconcentrating and separation of trace of Ga(III), In(III),Bi(III), Sn(IV)and Ti(IV) ions from sample solutions. The ions analyzed can be quantitatively enriched by the resin at a flow-rate of 2ml/min at pH4,and quantitatively desorbed with 10ml of 2mol/L HCl+0.2gCS(NH₂)₂ at a flow-rate of 1ml/min with recoveries of over 97%,The chelating resin can be reused 7times without obvious loss of efficiency.     

Synthesis and efficiency of an epoxy-tannin chelating resin for preconcentrating and separating various rare elements

A new epoxy-tannin chelating resin was synthesized from epoxy resin and used for the preconcentration and separation of rare elements. The acidity, rate, reuse, capacity and interference on the adsorption of ions on the resin as well as the conditions of desorption of these ions from the resin were investigated by means of inductively coupled plasma atomic emission spectrometry (ICP-AES). The composition of the resin and mechanism of enrichment for some ions were discussed. The results show that the relative standard deviations for the determination of 50 ng ml⁻¹ Ga(III), In(III), Bi(III) and Sn(IV), 10 ng ml⁻¹ La(III), Y(III), Cr(III), Ti(IV) and V(V) and 1.0 ng ml⁻¹ Be(II) were in the range of 0.5–4.5%. The contents of these elements in a sample solution from a smelter determined by the new method were in agreement with those values obtained by Zeeman atomic absorption spectrometry with an average error <3.4%.     

Spectrophotometric determination of molybdenum by extraction of its thiosulphate complex

A simple and rapid spectrophotometric determination of molybdenum is described. The molybdenum thiosulphate complex is extracted into isoamyl alcohol from 1·0–1·5M hydrochloric acid containing 36–40 mg of Na₂S₂O₃·5H₂O per ml. The absorbance at λ_max = 475 nm obeys Beer's law over the range 0–32 μg of Mo per ml of solvent phase. Up to 5 mg/ml of Ti(IV), V(V), Cr(VI), Fe(III), Co(II), Ni(II), U(VI), W(VI), Sb(III), 1 mg/ml of Cu(II), Sn(II), Bi(V) and 10 μg/ml of Pt(IV) and Pd(II) do not interfere. Large amounts of complexing agents interfere. The method has been applied to analysis of synthetic and industrial samples.     

Separation and gravimetric determination of barium using sulfadimethoxin salicylaldimine

Sulfadimethoxin salicylaldimine (SUDMSA) has been found to be a wide spectrum precipitant of a number of metal ions. The chelates are granular, stable, and quantitatively formed. SUDMSA has been utilized for the gravimetric determination of barium in the presence of Ca(II), Sr(II), Fe(III), As(III), Sb(III), Cr(III), Ag(I), Cu(II), Ni(II), Co(II), Mn(II), Cd(II), Zn(II), Hg(II), Pd(II), Mg(II), Tl(I), ZrO(II), Sn(IV). The St. of the chelate was confirmed by elemental analysis and IR data.     

Rapid and selective method for the spectrophotometric determination of tin using potassium ethylxanthate

Tin (II) forms a yellow complex with potassium ethylxanthate which can be extracted into chloroform. Tin is determined spectrophotometrically by measuring the absorbance at 360 nm. Beer's law is obeyed up to 120 g of Sn in the aqueous phase with a Sandell sensitivity of 0.013 g Sn/cm². Metal ions such as Ti(IV), Cr(VI), Mn(II), Cu(II), Zn(II), Al(III), U(VI), W(VI), Th(IV) and Zr(IV) do not interfere, but Mo(VI), Co(II) and Bi(III) do. Interference due to Fe(II, III), Ni(II) and V(V) is checked by suitable masking agents. Analysis of some synthetic and industrial samples has been carried out by the proposed method.     

Liquid-liquid extraction study of tellurium(IV) with N-n-octylaniline in halide medium and its separation from real samples

N-n-Octylaniline in xylene is used for extractive separation of tellurium(IV) from hydrochloric acid media. Tellurium(IV) is extracted quantitatively with the 3% reagent in xylene from 5.5 to 7.5 M hydrochloric acid. It is stripped from organic phase with 1:1 ammonia and estimated spectrophotometrically with pyrimidine-2-thiol (4'-bromoPTPT). The effects of metal ion, acids, reagent concentration, diluents and various foreign ions have been investigated. The log-log plots of distribution ratio (D(Te(IV))) versus N-n-octylaniline concentration indicate that the nature of extracted species is [(RR'NH(2)(+))(2) TeCl(6)(2-)](org). The method affords binary separation of tellurium(IV) from gold(III), selenium(IV), bismuth(III), copper(II), lead(II), antimony(III), germanium(IV) and is applicable to the analyses of synthetic mixture containing associated metal ions and alloy samples. The method is simple, selective, rapid and accurate.     

Capillary gas chromatographic analysis of pyrrolidinedithiocarbamate metal chelates

Pyrrolidinedithiocarbamate (PDTC) chelates of Zn(II), Cu(II), Ni(II), Co(III), Fe(III), Mn(II), Cr(III), and VO(II) were analysed by capillary GC on a DB-1701 column (30 m x 0.25 mm id) with flame ionisation detection (FID). Linear calibrations were attained within "1-30 microg/mL" for Ni(II), Fe(III), Mn(II), Cr(III), Cu(II), and VO(II), and within "2-50 microg/mL" for Co(III) and Zn(II). The limits of detection were in the "150-500 ng/mL" range, corresponding to 15-50 pg amounts reaching the FID system. The optimised method was applied to the determination of Cu(II) and Ni(II) in coins, and that of Zn(II), Cu(II), Ni(II), Fe(III), Mn(II), Cr(III), and VO(II) in pharmaceutical preparations with relative standard deviations within 1.1-5.2%. The results obtained are in good agreement with sewage water samples and the declared values for the pharmaceutical formulations, or with the results of AAS of metal contents in coins, pharmaceutical preparations, and sewage water samples.