Chromatography of inorganic ions on polyethyleneimine cellulose layer in hydrochloric acid — Ammonium thiocyanate media

Summary Thin-layer chromatographic behavior of 58 inorganic ions on polyethyleneimine (PEI) cellulose has been systematically surveyed in hydrochloric acid — ammonium thiocyanate media. In this media most of the ions distribute chromatographically on the layer. Ag(I), Hg(II), Pd(II), Au(III), Bi(III), Ru(III), Pt(IV), Nb(V), Ta(V), Mo(VI), and W(VI) are strongly retained, while alkali earths(II), Mg(II), As(III), Ti(IV), and Te(VI) are not absorbed to any great extent in this system. An interesting correlation was found between the R_f values on PEI-cellulose in the thiocyanate media and the paramagnetic moment of the rare earths(III). An oddeven fluctuation against the atomic number is also found for the heavy rare earths(III). Chromatographic separation of many inorganic ions of analytical interest is demonstrated in this system.     

Separation of rhenium by thin-layer chromatography with polyethyleneimine cellulose in hydrochloric acid media

Summary The thin-layer chromatographic behavior of 49 inorganic ions on polyethyleneimine (PEI) cellulose has been investigated in hydrochloric acid media (0.01–1.0 mol dm⁻³). The sorption on the cellulose decreases with increasing acid concentration for most of the ions, but As(III), Ti(IV) and Te(VI) do not exhibit any R_f variation with the acid concentration. The R_f spectra of TI(I), Cd(II), Pb(II) and Zn(II) have a maximum. Ag(I), Bi(III), Nb(V), Ta(V), Mo(VI) and W(VI) are retained tightly on the layer, due to either insoluble salt formation or extensive hydrolysis. The extremely low R_f values of Hg(II), Pd(II), Au(III), Ru(III) and Pt(IV) are accounted for by stability of their chlorocomplexes. Re(VII) distributes chromatographically, having moderate R_f values between 0.3 and 0.6, so that the selective separation of Re(VII) from the other ions is feasible.     

The chromatography of a number of metals on cellulose phosphate layers in sulfuric acid and ammonium sulfate media

Summary The thin-layer chromatographic behavior of 58 metals on an intermediately acidic cation exchanger, cellulose phosphate (P-cellulose), has been surveyed systematically in sulfuric acid and ammonium sulfate media (0.01–2.0 M). The R_f values for many bivalent and univalent metal ions on P-cellulose plates increase with increasing concentration of sulfate ions. Howerver, manganese (II), arsenic (III) and selenium (IV) are not adsorbed on the cellulose to any great extent. Beryllium (II) and other metals, which form either strong phosphate complexes or insoluble sulfate precipitates, are strongly retained on the P-cellulose. The thin-layer chromatographic separations of various metal ions of analytical interest were accomplished to demonstrate the use of R_f measurements for predicting separations in the acid and the sulfate media.     

Thin-Layer chromatography of inorganic ions on cellulose phosphate in sulfuric acid-organic solvent media

Summary Thin-layer chromatographic behavior of 49 inorganic ions on cellulose phosphate (P-cellulose) has systematically been surveyed with binary solvent mixtures consisting of sulfuric acid and an organic solvent such as methanol or acetone. The R_f values of many bivalent and monovalent ions as well as Te(VI) decrease on the P-cellulose layer with an increasing concentration of the organic solvent. Polyvalent ions which form strong phosphato-complexes and precipitate insoluble sulfate are strongly retained on P-cellulose. Oxy-anions, Au(III) and Pt(IV) are not adsorbed on the cellulose to any great extent. Feasibilities of the separation of multicomponent mixtures are demonstrated on the P-cellulose layer.     

Chromatography of inorganic ions on cellulose phosphate layer in hydrochlorid acid and in acid ammonium thiocyanate media

Summary Thin-layers of an intermediately acidic cation exchanger, cellulose phosphate (P-cellulose), have systematically been used to study the chromatographic behavior of 58 inorganic ions in both hydrochloric acid and acid ammonium thiocyanate media (0.01–2.0 mol dm⁻³). In both solvent systems, the R _f values of many bivalent cations increase with increasing concentration of the acid and thiocyanate. Polyvalent metal ions including beryllium (II) and the others are strongly retained on the P-cellulose in the acid and thiocyanate systems tested. Palladium(II), mercury(II), ruthenium(III), rhenium(VII), arsenic(III), selenium(IV) and tellurium(IV) are not adsorbed on P-cellulose to any great extent. For silver(I), indium(III), gold(III), and platinum(IV), there are marked differences in the chromatographic behavior between hydrochloric acid and acid ammonium thiocyanate systems. Multicomponent separations conducted on P-cellulose plates with these eluents are presented.     

Electrometric titrations of Cr(VI), Mn(IV), V(V), Co(III) and U(VI) with a standard iron(II) solution in alkaline media containing hexitols

Direct and indirect potentiometric, bipotentiometric and biamperometric titrations with a standard iron(II) solution are described for some inorganic compounds in alkaline media containing hexitols (mannitol, dulcitol and sorbitol). The optimal conditions for titrations based on the Cr(VI) → Cr(III), Mn(IV) → Mn(III) → Mn(II), V(V) → V(IV), Co(III) → Co(II) and U(VI) → U(IV) systems are discussed. Of the hexitols studied, sorbitol has the greatest effect on the value of the redox potential of the Fe(III)/Fe(II) system; the E_f° value is about —1.10 V vs. SCE.     

Combination collectors in adsorption colloid flotation for multielement determination in waters by neutron activation

A method is described for the collection of small amounts of both anions and cations in water samples by adsorption colloid flotation with a combination collector, prior to quantitation by neutron activation. In the presence of 20 mg of iron(III) and 2 ml of 0.1 M ammonium pyrrolidinedithiocarbamate, As(V), Cd(II), Co(II), Cu(II), Hg(II), Mo(VI), Sn(IV), Sb(III), Te(VI), Ti(IV), U(VI), V(V) and W(VI) are quantitatively collected from 1 -l samples at a pH 5.8 ± 0.1; sodium dodecyl sulfate and sodium oleate are used as surfactant. Recoveries for all the elements tested are greater than 90%. Results for a number of elements in sea waer and an NBS water standard, SRM 1643a, are given.     

The chromatography of metals on DEAE-cellulose layers in phosphoric acid media

The adsorption behaviour of forty-eight metals on DEAE-cellulose thin layers has been examined in aqueous phosphoric acid media. R_F values are given as a function of phosphoric acid concentration over the range 0.01–1.0 M and are compared with those obtained in a similar manner with a crystalline cellulose, Avicel SF. Particularly strong retention on DEAE-cellulose occurred for Mo(VI), W(VI), Re(VII), the platinum group metals, Au(III) and Bi(III). Weak to moderate retention was also observed for several metals, such as V(V), Fe(III), Se(IV), In(III), the rare earths and U(VI), at lower concentrations of phosphoric acid (<0.1 M).     

Application of the Weisz Ring oven technique to the separation and identification of micro-quantities of some less familiar cations

Summary Use of the ring oven in separation and identification of mixtures of less familiar metal ions has been described. Separation of metal ions from the following mixtures has successfully been carried out: 1. UO₂(II) and Th(IV), 2. Th(IV) and Ce(IV), 3. Pd(II) and Au(III), 4. Pt(IV) and Au(III), 5. Ce(III) and Ce(IV), 6. UO₂(II), Th(IV) and Ti(IV), 7. Th(IV), Ti(IV) and Ce(IV), 8. Th(IV), Ce(IV) and Zr(IV), 9. Ti(IV), V(V) and Zr(IV), 10. Mo(VI), V(V) and W(VI) and 11. Be(II), Al(III) and Mg(II). In the case of binary mixtures, the separation was in the form of a central spot and a concentric ring; in ternary mixtures the metals were precipitated in a central spot and two concentric rings.

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Zusammenfassung Zur Trennung und Identifizierung folgender Gemische seltenerer Metallionen wurde der Ringofen mit Erfolg verwendet: 1. UO₂(II) und Th(IV), 2. Th(IV) und Ce(IV), 3. Pd(II) und Au(III), 4. Pt(IV) und Au(III), 5. Ce(III) und Ce(IV), 6. UO₂(II), Th(IV) und Ti(IV), 7. Th(IV), Ti(IV) und Ce(IV). 8. Th(IV), Ce(IV) und Zr(IV), 9. Ti(IV), V(V) und Zr(IV), 10. Mo(VI), V(V) und W(VI) und 11. Be(II), Al(III) und Mg(II). Bei binären Gemischen erfolgt die Trennung in einen zentralen Fleck und einen Ring, bei ternären Mischungen in einen Fleck und zwei konzentrische Ringe.

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Résumé On a décrit l'utilisation du four annulaire pour la séparation et l'identification de mélanges d'ions métalliques moins courants. On a effectué la séparation des ions métalliques à partir des mélanges suivants: 1. UO₂(II) et Th(IV), 2. Th(IV) et Ce(IV), 3. Pd(II) et Au(III), 4. Pt(IV) et Au(III), 5. Ce(III) et Ce(IV), 6. UO₂(II), Th(IV) et Ti(IV), 7. Th(IV), Ti(IV) et Ce(IV), 8. Th(IV), Ce(IV) et Zr(IV), 9. Ti(IV), V(V) et Zr(IV), 10. Mo(VI), V(V) et W(VI) et 11. Be(II), Al(III) et Mg(II). Dans le cas des mélanges binaires, la séparation se présentait sous forme d'une tache centrale et d'un anneau concentrique; chez les mélanges ternaires, les métaux étaient précipités en une tache centrale et deux anneaux concentriques.

     

A new spot test for cerium(IV)

Summary A new colour reaction for the detection of cerram(IV) which can be carried out both in a test tube and on a spot plate has been described. The test solution is treated with methylene blue in nitric acid solution (11) to form a rose-red colour. This simple procedure has an advantage over the existing tests in that it is applicable in the presence of oxidising agents like chromium(VI), vanadium(V), nitrate, perchlorate and of coloured ions like copper(II), cobalt(II), nickel(II), chromium(III), iron(III), vanadium(IV), uranium(VI).

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Zusammenfassung Eine neue, sowohl in der Eprouvette wie auf der Tüpfelplatte ausführbare Farbreaktion zum Nachweis von Cer(IV) wurde angegeben. Die Probelösung wird mit salpetersaurer Methylenblaulösung behandelt und gibt eine rosarote Färbung. Die Reaktion hat gegenüber bekannten Tests den Vorteil, in Gegenwart von Oxydationsmitteln wie Cr(VI), V(V), NO₃ ^–, ClO₄ ^– bzw. in Anwesenheit gefärbter Ionen wie Cu(II), Co(II), Ni(II), Cr(III), Fe(III), V(IV) oder U(VI) anwendbar zu sein.

     

Untersuchungen zur anwendung ternärer komplexe in der photometrie—I Die bestimmung des Titan(IV) mit Tiron in gegenwart von äthylendiamintetraessigsäure

Two model systems and three analytical procedures based on them have been investigated analytically and characterized statistically with the aim of evaluating the application of ternary complexes in photometry. From measurements on the systems Ti(IV), Tiron (TiR^8?₃, procedure I), Ti(IV), Tiron, EDTA (TiR^8?₃, procedure II), Ti(IV), Tiron, EDTA [TiO(HY)R^5?, procedure III], the molar absorptivities, standard deviations, coefficients of variation, calibration data, limits of detection and determination have been calculated, and the possible interferences of 45 ions have been examined. Procedure III is shown to be the least sensitive of the three, but to offer a higher selectivity towards titanium in the presence of Cr(III), Cu(II), Fe(III), Mn(II), Mo(VI), Ni(II), U(VI) and W(VI). The reasons for this are discussed, and some suggestions are offered concerning the intended application of ternary complexes.     

Lanthanide Inorganic Solids Based on Main Group Borates and Oxyanions of Lone Pair Cations

Lanthanide 硼酸盐包含柱子转变金属主要的组元素,包括的 Ga ( III ), Ge ( IV ), Sb (V)和 Te ( VI ),以及孤独的对阳离子的 oxyanions 的 lanthanide 盐,例如我(V), Se ( IV )和 Te ( IV ),被考察。柱子转变金属在 lanthanide 硼酸盐的主要的组元素仅仅采用八面或有四面的几何学。在 lanthanide galloborates 的结构,当两八面的 GeO ₆ 和有四面的 GeO ₄ 出现在 borogermanates 时,仅仅八面的高 ₆ 被发现。第五时期元素 Sb (V) 和 Te (VI ) 在 lanthanide 硼酸盐系统比较喜欢八面的协作几何学。介绍给孤独的对的 lanthanide oxyanions 的第二个组主要那么集中于 d ⁰ TM 单位,例如 WO ₄ 四面体, VO ₅ 平方金字塔或哞 ₆ 八面体,和象硫酸盐一样的僵硬的有四面的组 ₄, 硅石 SiO ₄ 或硒酸盐 SeO ₄ 单位。象 Pb (II ) 和 Cu (II ) 或 Mn (II ) 的磁性的离子一样的二价的阳离子也被包括。在这些系统的 lanthanide 离子的结构化学是富有的。从六～十的协作数字被发现,产出包括五角的 bipyramid 的大量协作几何学,方形的 antiprism, metabidiminished 二十面体, tricapped 三角的棱柱,盖住的三角形的小圆屋顶,等等。在行 polyhedra 之间的连接模式是其他的,从 3D 网络,到 2D 层, 1D 链, tetramer,更整齐,更暗淡并且最后单体。很多混合物显示 NCS 结构和强壮的 SHG 反应,和许多 lanthanide 混合物展出好光性质在可见并且红外区域。     

Spectrophotometric determination of copper(II) using oximidobenzotetronic acid

Summary Oximidobenzotetronic acid (OBTA) is proposed as a sensitive spectrophotometric reagent for the estimation of 0.5–3.0 ppm of copper(II) at 427 nm in 50% dioxan at p_H 5.3–7.5. For the estimation of 2 ppm Cu(II), 1.3 ppm Ni(II), 1.3 ppm Co(II), 3.2 ppm Fe(II), 10.3 ppm Fe(III), 9.7 ppm Ce(IV), 300 ppm acetate, 160 ppm oxalate, 95 ppm tartrate, 50 ppm citrate, as well as Zn(II), Cd(II), Hg(II)) Pb(II), Mn(II), As(III) as well as (V), Th(IV), Be(II), Ce(III), La(III), V(V) and Mo(VI), even when present in large quantities, do not interfere. The interference due to 25 ppm Bi(III), 20 ppm Sb(III), 20 ppm Sn(II), 25 ppm Sn(IV) and 30 ppm W(VI) can be removed by the addition of 95 ppm tartrate ions.

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Zusammenfassung Oximidobenzotetronsäure wurde als empfindliches Reagens zur spektrophotometrischen Bestimmung von 0,5 bis 3,0 ppm Kupfer(II) bei 427 nm in 50%iger Dioxanlösung bei p_H 5,3 bis 7,5 vorgeschlagen. Die Anwesenheit von 1,3 ppm Ni(II), 1,3 ppm Co(II), 3,2 ppm Fe(II), 10,3 ppm Fe(III), 9,7 ppm Ce(IV), 300 ppm Acetat, 160 ppm Oxalat, 95 ppm Tartrat, 50 ppm Citrat sowie die Anwesenheit auch großer Mengen Zn(II), Cd(II), Hg(II), Pb(II), Mn(II), As(III) bzw. (V), Th(IV), Be(II), Ce(III), La(III), V(V) und Mo(VI) stören die Bestimmung von 2 ppm Cu(II) nicht. Der störende Einfluß von 25 ppm Bi(III), 20 ppm Sb(III), 20 ppm Sn(II), 25 ppm Sn(IV) und 30 ppm W(VI) kann durch Zusatz von 95 ppm Tartrat beseitigt werden.

     

Chromatographic behaviour of a number of metal ions on DEAE-cellulose layers in thiosulfate media

The adsorption behavior of 47 metal ions on DEAE-cellulose (Cl⁻) has been surveyed in aqueous thiosulfate solution by thin-layer chromatographic technique. The R_f values are measured as a function of thiosulfate concentration (0.010–2.0M) and are compared with those obtained on a microcrystalline cellulose Avicel SF. Generally, the ion-exchange adsorption of metal ions are weak or moderate over the thiosulfate concentration range tested except for a few metal ions like Mo(VI), Sb(III), Bi(III) etc., which have high preference to DEAE-cellulose. A variety of chromatographic distribution exhibited by metal ions allows to develop a number of separations of analytical and radiochemical interest.     

Voltammetry and controlled-potential coulometry with boron carbide electrodes

With the boron carbide electrode, E_{p$\text{p}\text{2}$} values were determined for the reduction of the following ions: Cd(II), Co(II), Cu(II), Fe(III), Ni(II), Pb(II), Ru(IV), Sb(V), and U(VI). The linear dependence of peak current on concentration is demonstrated for the U(VI) → U(IV) and Fe(III) → Fe(II) reductions at the boron carbide electrode. The suitability of the electrode for the controlled-potential coulometric ti trations of Fe(II) → Fe(III), Fe(III) → Fe(II), and U(VI) → U(IV) was studied; the results were inconclusive because of the small surface area that could be used conveniently and the possibility of oxygen leaks in the cell.     

Preparation, characterization and application of an cellulose ion-exchanger with acetoacetamide functional groups

Summary A method is described for functionalizing acetoacetamide chelating groups onto microcrystalline cellulose (Cell-AcAc). This material shows a significant affinity for Fe(III), Cu(II) and U(VI) and no or very less affinity for the M(I) ions (M=Na, K), M(II) ions (M= Mg, Ca; Fe, Co, Ni, Zn), La(III) and Y(III) including Th(IV). The obtained K _d values offer a column separation method for U(VI) ions from the rest of above-mentioned metal ions except Fe(III). Cell-AcAc and its Cu(II) complexes are characterized by means of FT-IR spectra.

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Darstellung, Charakterisierung und Anwendung von Ionenaustauschmaterial aus Cellulose mit chemisch gebundener Acetoacetamid-Gruppe

Zusammenfassung Die Darstellung von immobilisiertem Acetoacetamid auf mikrokristallinem Cellulosepulver (Cell-AcAc) wird beschrieben. Der Ionenaustauscher Cell-AcAc hat eine ausgeprägte Affinität für Fe(III), Cu(II) and U(VI), aber nahezu keine für die M(I)-Ionen (M=Na, K) M(II)-Ionen (M=Mg, Ca; Fe, Co, Ni, Zn), La(III), Y(III) sowie Th(IV). Die erhaltenen K _d-Werte ermöglichen für U(VI)-Ionen eine quantitative säulen-chromatographische Trennung von den anderen genannten Kationen mit Ausnahme von Fe(III). Das Ionenaustauschmaterial Cell-AcAc und sein Cu(II)-Komplex wurden durch FT-IR-Spektren charakterisiert.

     

A chelating resin containing 1-(2-thiazolylazo)-2-naphthol as the functional group; synthesis and sorption behavior for trace metal ions

A new polystyrene-divinylbenzene resin containing 1-(2-thiazolylazo)-2-naphthol (TAN) functional group was synthesized and its sorption behavior for 19 metal ions including Zr(IV), Hf(IV) and U(VI) was investigated by batch and column experiments. The chelating resin showed a high sorption affinity for Zr(IV) and Hf(IV) at pH 2. Some parameters affecting the sorption of the metal ions are detailed. The breakthrough and overall capacities were measured under optimized conditions. The overall capacities of Zr(IV) and Hf(IV) that were higher than those of the other metal ions were 0.92 and 0.87 mmol/g, respectively. The elution order of metal ions at pH 4 was evaluated as: Zr(IV)>Hf(IV)>Th(IV)>V(V)>Nb(V)>Cu(II)>U(VI)>Ta(V)>Mo(VI)>Cr(III)>Sn(IV)>W(VI). Quantitative recovery of most metal ions except Zr(IV) was achieved using 2 M HNO₃. Desorption and recovery of Zr(IV) was successfully performed with 2 M HClO₄ and 2 M HCl.     

Extractive-spectrophotometric determination of molybdenum with 4-unsubstituted-5-pyrazolones

A fairly sensitive and selective method for rapid determination of tracer amounts of molybdenum(V) as mixed-ligand complexes with thiocyanate and 4-unsubstituted-5-pyrazolones is described. The red complexes are extractable into chloroform from 1-5M hydrochloric or perchloric acid or 1-3M sulphuric arid media. The molar absorptivities are in the range 1.72-2.15 x 10(4)l.mole(-1).cm(-1) at 455 nm (lambda(max)). The method has been applied to the estimation of molybdenum in various synthetic and alloy-steel samples. In presence of excess of the reagent, Cu(II), Co(II), Mn(II), Fe(II), Fe(III), Al(III), Cr(III), Cr(VI), Ti(III), Ti(IV), Zr(IV), Hf(IV), V(III), V(IV), V(V), Nb(V), Ta(V), W(VI) and U(VI) do not interfere.     

The spectrophotometric determination of vanadium after extraction as vanadium(III) ferronate by tribenzylamine

Vanadium(III) obtained by dithionite reduction of vanadium(V) can be extracted as its ferron complex with tribenzylamine in chloroform from 0.05 M sulphuric acid. Vanadium (0–5 μg ml^-1) is determined spectrophotometrically at 430 nm with a sensitivity of 0.0028 μg V cm^-2. Al(III), Co(II), Ni(II), Fe(II, III), Hg(II), Si(IV), Be(II), Mg(II), Ca(II), Sr(II), Ba(II), Cr(VI, III), W(VI), Zn(II), U(VI), Mn(II). Pb(II), Cu(II), Cd(II) and Th(IV) do not interfere; only Mo(VI), Ti(IV), Zr(IV). Bi(V) and Sn(II) interfere. A single determination takes only 7 min. The extracted complex is V^III (R-3H.TBA)₃ where R = C₉H₄O₄NSI. The method is satisfactory for the determination of vanadium in steels, alum and other samples without preliminary separations.     

Metal-based anti-diabetic drugs: advances and challenges

The current status and likely future directions of complexes of V(V/IV), Cr(III), Mo(VI), W(VI), Zn(II), Cu(II), and Mn(III) as potential oral drugs against type 2 diabetes are reviewed. We propose a unified model of extra- and intracellular mechanisms of anti-diabetic efficacies of V(V/IV), Mo(VI), W(VI), and Cr(III), centred on high-oxidation-state oxido/peroxido species that inhibit protein tyrosine phosphatases (PTPs) involved in insulin signalling. The postulated oxidative mechanism of anti-diabetic activity of Cr(III) via carcinogenic Cr(VI/V) (which adds to safety concerns) is consistent with recent clinical trials on Cr(III) picolinate, where activity was apparent only in patients with poorly controlled diabetes (high oxidative stress), and the correlation between the anti-diabetic activities and ease of oxidation of Cr(III) supplements and their metabolites in vivo. Zn(II) and Cu(II) anti-diabetics act via different mechanisms and are unlikely to be used as specific anti-diabetics due to their diverse and unpredictable biological activities. Hence, future research directions are likely to centre on enhancing the bioavailability and selectivity of V(V/IV), Mo(VI), or W(VI) drugs. The strategy of potentiating circulating insulin with metal ions has distinct therapeutic advantages over interventions that stimulate the release of more insulin, or use insulin mimetics, because of many adverse side-effects of increased levels of insulin, including increased risks of cancer and cardiovascular diseases.