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%.     

碱改性γ-Al_2O_3催化剂上羰基硫的低温水解反应 Ⅰ.催化剂活性及补偿效应

以γ-Al_2O_3为载体,用浸渍法负载碱金属和碱土金属氧化物制备了一系列羰基硫水解催化剂。采用微反-色谱联用装置考察了45—100℃低温区内的活性变化规律。结果表明,催化剂活性与金属氧化物组分及含量有着密切关系。在考察各催化剂在不同温度下水解反应速度常数(K)的变化中,发现指前因子(A)与活化能(E)之间存在着补偿效应,活化能增大时指前因子也随之增大。补偿效应参数(K_0)和能量分布指前因子(1/b)均与负载的金属离子半径(d_m)有关。求得了各催化剂的等动力学温度(T),讨论了羰基硫水解反应中存在补偿效应的原因。     

Charge-on-spring polarizable water models revisited: from water clusters to liquid water to ice

The properties of two improved versions of charge-on-spring (COS) polarizable water models (COS/G2 and COS/G3) that explicitly include nonadditive polarization effects are reported. In COS models, the polarization is represented via a self-consistently induced dipole moment consisting of a pair of separated charges. A previous polarizable water model (COS/B2), upon which the improved versions are based, was developed by Yu, Hansson, and van Gunsteren. To improve the COS/B2 model, which overestimated the dielectric permittivity, one additional virtual atomic site was used to reproduce the water monomer quadrupole moments besides the water monomer dipole moment in the gas phase. The molecular polarizability, residing on the virtual atomic site, and Lennard-Jones parameters for oxygen-oxygen interactions were varied to reproduce the experimental values for the heat of vaporization and the density of liquid water at room temperature and pressure. The improved models were used to study the properties of liquid water at various thermodynamic states as well as gaseous water clusters and ice. Overall, good agreement is obtained between simulated properties and those derived from experiments and ab initio calculations. The COS/G2 and COS/G3 models may serve as simple, classical, rigid, polarizable water models for the study of organic solutes and biopolymers. Due to its simplicity, COS type of polarization can straightforwardly be used to introduce explicit polarization into (bio)molecular force fields.     

Application of an imidazoline group-containing chelating fiber for the determination of trace noble metals in superhigh-temperature alloys

An imidazoline group-containing chelating fiber was prepared by means of the reaction of nitrile groups with ethylenediamine in an hydrazine-modified polyacrylonitrile fiber. The adsorption properties of the chelating fiber for Au(III), Pd(II), Pt(IV), Ir(IV), Os(IV), Rh(III) and Ru(IV) ions, such as binding capacity, distribution coefficient, sorptive rate and quantitative elution of Au(III), Pd(II) and Pt(IV) ions were investigated. The imidazoline group-containing chelating fiber possessed high binding capacities and good adsorption kinetic properties, exhibited high affinity for noble metals in 0.1–1.0 mol/L HCl and could be efficiently re-used. After the separation of trace Au(III), Pd(II) and Pt(IV) ions from a matrix using the chelating fiber, these ions could be determined by ICP-AES with satisfactory results, and the relative standard deviation for Au(III), Pd(II) and Pt(IV) ions was less than 6%. Received: 5 July 1999 / Revised: 4 October 1999 / Accepted: 4 October 1999     

Theoretical Study on the Reaction of FeS+(6∑+,4Ф)with COS in the Gas Phase

The possible reaction mechanisms of FeST(6∑+and 4Ф states)with COS in the gas phase have been studied by using density functional theory at the B3LYP/TZVP and B3LYP/6-311+G*levels:the O/S exchange reaction(FeS++COS=FeO++CS2),O-transfer reaction(FeS++COS=FeSO++CS)and S-transfer reaction(FeS++COS=FeS2++CO).The calculation results show that the large barriers(205.7 and 310.1 kJ/mol)and the small probability of forming the preceding intermediate indicate a much lower efficiency of the O/S exchange and the O-transfer reactions and their corresponding products may not be observed experimentally.FeS2+,the product of S-transfer reaction,is predicted to be the main product.But the reactivity of the 6∑+ground state of FeS+toward COS is lower than the earlier transition metal sulfide cations MS+(M=Sc,Ti and V),although it has more reaction channels and different mechanisms.     

Solid phase extraction and determination of metal ions in aqueous samples using Quercetin modified Amberlite XAD-16 chelating polymer as metal extractant

A new chelating polymer has been developed using Amberlite XAD-16 anchored with Quercetin. The modified polymer was characterised by Fourier Transform Infra Red (FTIR) spectroscopy, thermogravimetric analysis, surface area analysis and elemental analysis. The Quercetin anchored polymer showed superior binding affinity for Cr(III), Mn(II), Fe(III), Co(II), Ni(II) and Cu(II) with greater than 95% adsorption under optimum conditions. The optimum pH conditions for the quantitative sorption of metal ions were studied. The developed method showed superior extraction qualities with high metal loading capacities of 387, 313, 195, 473, 210 and 320 µmol g^?1 for Cu(II), Co(II), Cr(III), Fe(III), Mn(II) and Ni(II), respectively. The rate of metal ion uptake i.e. kinetics studies performed under optimum levels, showed t _1/2 for Co(II), Cu(II), Cr(III), Fe(III), Mn(II) and Ni(II) is 20, 15, 25, 10, 30 and 15 min, respectively. Desorption of metal ions was effective with 10 mL of 2 M HCl prior to analysis using flame atomic absorption spectrophotometer. The chelating polymer was highly ion selective in nature even in the presence of interferent ions, with a high preconcentrating ability for the metal ions of interest. The developed chelating polymer was tested on its utility with synthetic and real samples like river, tap water samples and also with multivitamin tablets. It showed relative standard deviation (R.S.D.) values of/less than 3.0% reflecting on the accuracy and reproducibility of data using the newly developed chelating polymer.     

Application of an imidazoline group-containing chelating fiber for the determination of trace noble metals in superhigh-temperature alloys

An imidazoline group-containing chelating fiber was prepared by means of the reaction of nitrile groups with ethylenediamine in an hydrazine-modified polyacrylonitrile fiber. The adsorption properties of the chelating fiber for Au(III), Pd(II), Pt(IV), Ir(IV), Os(IV), Rh(III) and Ru(IV) ions, such as binding capacity, distribution coefficient, sorptive rate and quantitative elution of Au(III), Pd(II) and Pt(IV) ions were investigated. The imidazoline group-containing chelating fiber possessed high binding capacities and good adsorption kinetic properties, exhibited high affinity for noble metals in 0.1-1.0 mol/L HCl and could be efficiently re-used. After the separation of trace Au(III), Pd(II) and Pt(IV) ions from a matrix using the chelating fiber, these ions could be determined by ICP-AES with satisfactory results, and the relative standard deviation for Au(III), Pd(II) and Pt(IV) ions was less than 6%.     

Synthesis of poly(acrylamidrazone-hydrazide) chelating fiber and application of enrichment-separation for traces of indium, tin, chromium, vanadium and titanium from solution samples

A poly(acrylamidrazone-hydrazide) chelating fiber has been synthesized from polyacrylonitrile fiber and used for enrichment-separation of traces of In(III), Sn(IV), Cr(III), VO(I) and Ti(IV) from solution samples with satisfactory results. These ions (5-250 ng/ml) can be quantitatively enriched (recovery > 95%) by the fiber at a 10 ml/min flow rate in the pH range 4-7, and desorbed quantitatively (recovery > 95%) with 10 ml of 2-5M hydrochloric acid from a fiber column at 6 ml/min flow rate. When the fiber, which had been stored in a glass bottle for about two years and then treated with strong acids (concentrated hydrochloric or nitric acid), was reused 10 times, the recoveries of the above ions by enrichment were still over 94%, and hundred-fold to thousand-fold excesses of Cu(II), Zn(II), Co(II), Ca(II), Mg(II), Fe(III) and Al(III) caused little interference in the determination of these ions by ICP-AES. The lowest concentrations for the proposed method were 50 ng/ml and In and Sn and 5 ng/ml for Cr, V and Ti. The RSD was 1.2-4.0%. The contents of these ions in real solution samples determined by this method were basically in agreement with the certified values of the samples, with average errors below 3.3%. The IR spectra of the fiber adsorbed with Cr(III) or VO(I) showed that Cr(III) or VO(I) combined mainly with nitrogen atoms in the fiber to form a coordination complex.     

Reaction Mechanism of H2-Assisted C3H6-SCR over Ag-CexZr Catalyst as Investigated by In situ FTIR

A series of silver-doped cerium zirconium oxide(Ag-Ce_xZr) samples was synthesized successfully for selective catalytic reduction of nitric oxide(NO) with hydrogen and propene(H₂/C₃H₆-SCR) under excess oxygen condition. The catalytic activity test proved that Ag-Ce_0.4Zr exhibited the best C₃H₆-SCR activity. Hydrogen(H₂) significantly enhanced NO conversion and widened the temperature window. Multi-technology characterizations were conducted to ascertain the properties of fabricated catalysts including X-ray diffraction(XRD), Fourier transform infrared spectrometry(FTIR), scanning electron microscopy(SEM) and H₂ temperature programmed reduction (H₂-TPR). In situ FTIR results demonstrated that various types of nitrates and chelating nitrite were generated on Ag-Ce_xZr after introduction of NO. Besides, adding H₂ could increase the concentration of bidentate nitrate and chelated bidentate nitrate dramatically, especially for Ag-Ce_0.4Zr catalyst. Transient reaction between pre-adsorbing NO and C₃H₆/C₃H₆+H₂ illuminated that the most active intermediate was chelating nitrite,which was promoted significantly by H₂ participation. Furthermore, adding H₂ improved the formation of organo-nitro(R-NO₂), which was the key intermediate in C₃H₆-SCR. The reaction mechanism over Ag-Ce_xZr catalysts was proposed at 200℃ as follows:nitric oxide(NO)+propene(C₃H₆)+hydrogen(H₂)+oxygen(O₂)→chelating nitrite(NO₂^-)+acrylate-type species(C_xH_yO_z)→organo-nitro(R-NO₂)→isocyanate(-NCO)+cyanide(-CN)→nitrogen(N₂).     

Copolymerization of Carbonyl Sulfide and Propylene Oxide via a Heterogeneous Prussian Blue Analogue Catalyst with High Productivity and Selectivity

This study demonstrates the superiority of a stable and well-defined heterogeneous cobalt hexacyanocobaltate (Co₃[Co(CN)₆]₂), a typical cobalt Prussian Blue Analogue (CoCo-PBA) that catalyzes the copolymerization of carbonyl sulfide (COS) and propylene oxide (PO) to produce poly(propylene monothiocarbonate)s (PPMTC). The number-average molecular weights of the PPMTC were 66.4 to 139.4 kg/mol, with a polydispersity of 2.0–3.9. The catalyst productivity reached 1040 g polymer/g catalyst (12.0 h). The oxygen-sulfur exchange reaction (O/S ER), which would generate random thiocarbonate and carbonate units, was effectively suppressed, and thus the selectivity of the monothiocarbonate over carbonate linkages was up to >99%. It was shown that no cyclic thiocarbonate byproduct was produced during the heterogeneous catalysis of COS/PO copolymerization using CoCo-PBA as the catalyst. The content of monothiocarbonate and ether units in the copolymer chain could be regulated by tuning the feeding amount of COS.     

Evaluation of dithiocarbamates and beta-diketones as chelating agents in supercritical fluid extraction of Cd, Pb, and Hg from solid samples

The use of four dithiocarbamates and three fluorinated β-diketones as potential chelating agents for three transition metal ions (Cd²⁺, Pb²⁺, and Hg²⁺) extracted from spiked sand and filter paper samples by supercritical fluid extraction (SFE) was investigated. The extractions were performed at 45°C and 250 atm for spiked sand samples and at 60°C and 200 atm for filter paper samples using supercritical carbon dioxide modified with 5% methanol. At 250 atm and using carbon dioxide modified with 5% methanol, the recoveries of Cd²⁺, Pb²⁺, and Hg²⁺ ions from spiked sand samples were 95% with lithium bis(trifluoroethyl)dithiocarbamate (LiFDDC) as the chelating agent; they ranged from 83–97% with diethylammonium diethyldithiocarbamate and from 87–97% with sodium di-ethyldithiocarbamate as chelating agents, and from 68–96% with trifluoracetylacetone, hexafluoroacetylacetone, and thenoylfluoroacetone as chelating agents. Ammonium pyrrolidinedithiocarbamate was not effective in the chelation SFE of Cd²⁺, Pb²⁺, and Hg²⁺ ions from either spiked sand or spiked filter paper samples under the extraction conditions used. Supercritical carbon dioxide alone gave consistently lower analyte recoveries than supercritical carbon dioxide modified with 5% methanol. The results suggest that the solubility of the metal chelate in the supercritical fluid plays a more important role than the solubility of the chelating agent in the supercritical fluid, as long as sufficient chelating agent is present in the fluid phase. Fluorination of the chelating agent, as in the case of LiFDDC, increases the solubility of the metal chelate, and subsequently enhances the extraction efficiency for the metal ions.     

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.     

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.     

Potentiometric responses of polymeric liquid membranes based on hydrophobic chelating agents to metal ions.

The effect of hydrophobicity of acidic chelating agents as sensing materials on the potentiometric responses of polymeric liquid membranes was investigated. The chelating agents tested were 8-quinolinol (HOx), dithizone (HDz), 1-(2-pyridylazo)-2-naphthol (PAN) and their alkylated analogues, 5-octyloxymethyl-8-quinolinol (HO8Q), di(phexylphenyl)thiocarbazone (C6HDz), 7-pentadecyloxy-1-(2-pyridylazo)-2-naphthol (C15PAN) and a series of N-alkylcarbonyl-N-phenylhydroxylamines (CnPHA, n = 3, 6, 9, 12). The distribution coefficients between membrane solvent and water were determined to evaluate the hydrophobicity of the agents. The potential-pH profiles of the membranes containing hydrophobic chelating agents demonstrated the generation of potentiometric responses, while less hydrophobic agents gave no response. A possible model for the generation of membrane potential is proposed. The charge separation is attained by the permselective uptake of metal cations by the chelating agent anion at membrane/solution interface, where the high hydrophobicity of the agent enables the anionic or deprotonated form of the agents to remain at the membrane/solution interface.     

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.     

新型含氮、硫纤维素螯合树脂的合成及其吸附性能

将稻壳纤维素的氯化产物(CDC)分别与水合肼、乙二胺、二乙烯三胺、三乙烯四胺、丁二胺和己二胺反应,合成了6种含氮纤维素螯合树脂(ADC-1～ADC-6);在碱性条件下用环硫氯丙烷交联ADC合成了6种新型含氮、硫纤维素螯合树脂(TADC-1～TADC-6),研究了合成条件和ADC,TADC树脂对金属离子的吸附性能.结果表明,ADC树脂对Cu²⁺,Cr³⁺,Ni²⁺,Hg²⁺,Zn²⁺等离子有较好的吸附性,对Hg²⁺吸附容量可达0.5mmol/g左右;TADC树脂对Ag⁺,Cu²⁺,Hg²⁺等离子有较好的吸附性,对Hg²⁺和Ag⁺吸附容量可达1.1mmol/g和1.9mmol/g左右;强酸性条件下,ADC和TADC树脂的吸附容量都降低,它们对金属离子的吸附顺序分别为Hg²⁺>Cu²⁺>Ni²⁺和Ag⁺>Hg²⁺>Cu²⁺,树脂用10%的氨水解吸附可重复使用.     

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.

     

A new chelating sorbent for metal ion extraction under high saline conditions

A new chelating polymeric sorbent was developed by functionalizing Amberlite XAD-16 with 1,3-dimethyl-3-aminopropan-1-ol via a simple condensation mechanism. The newly developed chelating matrix offered a high resin capacity and faster sorption kinetics for the metal ions such as Mn(II), Pb(II), Ni(II), Co(II), Cu(II), Cd(II) and Zn(II). Various physio-chemical parameters like pH-effect, kinetics, eluant volume and flow rate, sample breakthrough volume, matrix interference effect on the metal ion sorption have been studied. The optimum pH range for the sorption of the above mentioned metal ions were 6.0–7.5, 6.0–7.0, 8.0–8.5, 7.0–7.5, 6.5–7.5, 7.5–8.5 and 6.5–7.0, respectively. The resin capacities for Mn(II), Pb(II), Ni(II), Co(II), Cu(II), Cd(II) and Zn(II) were found to be 0.62, 0.23, 0.55, 0.27, 0.46, 0.21 and 0.25 mmol g⁻¹ of the resin, respectively. The lower limit of detection was 10 ng ml⁻¹ for Cd(II), 40 ng ml⁻¹ for Mn(II) and Zn(II), 32 ng ml⁻¹ for Ni(II), 25 ng ml⁻¹ for Cu(II) and Co(II) and 20 ng ml⁻¹ for Pb(II). A high preconcentration value of 300 in the case of Mn(II), Co(II), Ni(II), Cu(II),Cd(II) and a value of 500 and 250 for Pb(II) and Zn(II), respectively, were achieved. A recovery of >98% was obtained for all the metal ions with 4 M HCl as eluting agent except in the case of Cu(II) where in 6 M HCl was necessary. The chelating polymer showed low sorption behavior to alkali and alkaline earth metals and also to various inorganic anionic species present in saline matrix. The method was applied for metal ion determination from water samples like seawater, well water and tap water and also from green leafy vegetable, from certified multivitamin tablets and steel samples.     

C207联醇催化剂的羰基硫中毒研究

以常压甲醇分解反应为基础实验测定了不同羰基硫含量和不同反应温度下甲醇合成铜基催化剂活性随时间的变化。结果表明，羰基硫含量增加时；失活速率增快；反应温度升高时，失活速率也加快。羰基硫中毒前后催化剂样品的ＸＲＤ谱图证实了起催化作用的活性组分为Ｃｕ＾＋／ＺｎＯ。应用改进的高斯－牛顿法对失活实验数据进行参数估值，获得了Ｃ２０７铜基催化剂羰基硫中毒的失活速率方程。     

Use of isooctyl thioglycolate for the separation of tin and antimony

The extraction characteristics of isooctyl thioglycolate (IOTG), a chelating agent, in various diluents has been studied with respect to the metal ions, tin(IV) and antimony(III), in hydrochloric acid medium. It is concluded that antimony(III) can be separated from tin(IV) with 85% yield and with a decontamination factor of at least 1·10⁵ using IOTG diluted with petroleum ether and 3M HCl medium. Tin(IV) can be separated conveniently from antimony(III) in 2M HCl with 95% yield and with a decontamination factor greater than 7·10⁵ using IOTG diluted with carbon tetrachloride.