Mg Of Antimony Research Articles

New “Magmolecular” Process for the Separation of Antimony(III) from Aqueous Solution

In this work, the separation potential of a new “magmolecular” process for ions of antimony(III) from wastewater was studied. The magmolecular process is a technique in which a high gradient magnetic field is applied to eliminate heavy metal from wastewater. In this process, specifically we have synthesized two nanoadsorbent magnetic materials, MnFe2O4 nanoparticles both uncoated (MNPs) and amino-modified coated (AS-MNPs), and used them to remove antimony(III) from synthetic wastewater. Several variables affecting the adsorption behavior such as pH, contact time, temperature, amount of MNPs and AS-MNPs, initial concentration of antimony(III), and influences of co-ions were studied. The kinetics was exanimated using the Lagergren pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion methods. The equilibrium results were evaluated by Langmuir, Freundlich, and Dubinin–Radushkevich equations. The uptake was relatively rapid and followed pseudo-second-order kinetics in a manner suggesting chemical sorption. The best commentary for the adsorption results was obtained by the Langmuir model, and the maximum uptake capacity of MNPs and AS-MNPs was found to be (10.66 and 7.78) mg of antimony(III) per gram adsorbent at conditions of pH 2 and temperature of 298 K, respectively. Thermodynamic factors indicated that the uptake process was endothermic, spontaneous, and chemical in nature. After five uptake–desorption cycles, results showed that uptake–desorption efficiencies of AS-MNPs were better than that of MNPs.

Clinical Efficacy and Pharmacokinetics of Antimony in Cutaneous Leishmaniasis Patients Treated With Sodium Stibogluconate

The efficacy and pharmacokinetics of antimony were explored in 12 young male patients with cutaneous leishmaniasis following intramuscular administration of sodium stibogluconate equivalent to 600 mg of antimony (Sb). Patients' cure rate was evaluated up to 6 weeks after treatment. Blood samples were collected at different time periods on the first and last days of a 3-week treatment. Twenty-four-hour urine samples were also collected on both occasions for the estimation of renal clearance (CL(r)). The blood concentrations of the Sb time profile were best described by a 2-compartment model with a first-order absorption rate. The mean absorption half-life was 0.21 ± 0.023 and 0.36 ± 0.18 hours for the first and last doses, respectively. A rapid distribution phase was followed by a slower elimination phase of a half-life of 9.4 ± 1.9 and 9.69 ± 2.3 hours for both days, respectively. An accumulation index of 2.33 was calculated. The fraction of dose excreted in urine was 0.386 ± 0.11 and 0.326 ± 0.05 on both occasions, respectively. The mean CL(r) was 4.88 ± 1.13 and 4.58 ± 1.05 L/h. In the current study, all of the patients were completely healed by week 6 after the end of treatment, as judged by the treating physician. In conclusion, the blood profile of antimony seems to be multicompartmental in nature.

Visceral leishmaniasis during pregnancy treated with meglumine antimoniate

Data on the efficacy and safety of pentavalent antimony in the treatment of visceral leishmaniasis during pregnancy are scanty. A case of visceral leishmaniasis in a 39-year-old woman in the second trimester of pregnancy is reported here. The patient was hospitalized in poor condition with high fever and pancytopenia which had lasted for 6 weeks. A bone marrow aspirate revealed numerous amastigotes and serodiagnosis for Leishmania was positive at a high titer. The patient was successfully treated with meglumine antimoniate at a daily dose of 850 mg of antimony for 20 days. She delivered at term a healthy female baby who remains in good condition at 18 months of age. Thus a dose of 850 mg of antimony, which is lower than that presently recommended, seems to be effective and non toxic to the fetus when administered at the second trimester of pregnancy.

Efficacy of a Short Course (10 Days) of High-Dose Meglumine Antimonate With or Without Interferon- in Treating Cutaneous Leishmaniasis in Guatemala

Sixty-six Guatemalan men with parasitologically confirmed cutaneous leishmaniasis, due most commonly to Leishmania braziliensis, were randomly assigned to receive one of three treatment regimens: meglumine antimonate (meglumine) for 20 days; meglumine for 10 days; and meglumine for 10 days plus alternate-day injections of interferon-gamma. In each group, meglumine was given intravenously as 20 mg of antimony/(kg of body weight.d). All treatment regimens were associated with similar response rates: the lesions of 19 (90%) of 21 patients who received meglumine for 20 days, 18 (90%) of 20 patients who received meglumine for 10 days, and all 22 patients who received meglumine plus interferon-gamma were completely reepithelialized by 13 weeks. In addition, for patients receiving all treatment regimens, test-of-cure cultures for Leishmania were negative and reactivation of lesions did not occur during 12 months of follow-up. The high efficacy of our 10-day course of meglumine indicates that the currently recommended duration of 20 days may be unnecessary for infections caused by L. braziliensis and suggests that a 10-day course of high-dose antimony should be tested as therapy for cutaneous leishmaniasis in other geographic areas.

Coated-wire ion-selective electrode for the determination of antimony(V)

The construction, performance characteristics, and applications of a coated-wire antimony(V) ion-selective electrode, based on the ion pair between hexachloroantimonate(V) and the 1,2,4,6-tetraphenylpyridinium cation in a poly(vinyl chloride) matrix, are described. Applications to the potentiometric titration of 0.03-3.0 mg of antimony(V) and to the direct potentiometric determination of antimony in sphalerites, bronzes, and iron oxide pigments are reported

Chemotherapy for Leishmaniasis: Biochemical Mechanisms, Clinical Efficacy, and Future Strategies

The 1980s have seen significant advances in the treatment of cutaneous, mucosal, and visceral leishmaniasis. Safe regimens of pentavalent antimony in the form of Pentostam (Wellcome Foundation, London; 20 mg of antimony/[kg.d] for 20-30 days) have produced initial cure rates of greater than 90% in these diseases. Biochemical investigations have demonstrated at least three parasite-specific features relevant to the mechanism of action of chemotherapeutic agents: (1) Organization of glycolytic enzymes and some enzymes of fatty acid catabolism into organelles (glycosomes) occurs in Leishmania but not in mammalian cells. Since antimony inhibits both amastigote catabolism of glucose via glycolytic enzymes and catabolism of fatty acids, the mechanism of action of antimony may relate to alteration of glycosomal structure or function. (2) Purine analogues can be utilized by the salvage pathway of purine biosynthesis in amastigotes to a greater extent than in mammalian cells, and allopurinol and allopurinol ribonucleoside are metabolized into presumably toxic nucleotides by these means. (3) Amastigote sterol biosynthesis is akin to that of such fungi as Candida in that the major demethylated sterol is of the ergostane series and in that ketoconazole inhibits its synthesis. Preliminary clinical studies suggest that the purines and the sterol inhibitors may have clinical utility as oral agents against cutaneous leishmaniasis. Possible treatment strategies for the classic and experimental agents have been proposed.

Spectrophotometric determination of germanium in ores, concentrates, zinc-processing products and related materials with phenylfluorone and cetyltrimethylammonium bromide after separation by iron collection and heptane extraction of germanium tetrachloride

A method for determining ~0.2 μg g or more of germanium in ores, concentrates, zinc-processing products and related materials is described. The sample is decomposed by fusion with sodium peroxide and the cooled melt is dissolved in dilute sulphuric acid. Silica, if > 50 mg, is removed by volatilization with hydrofluoric acid. Germanium is separated from sodium salts by co-precipitation with hydrous ferric oxide, the precipitate is dissolved in 3 M hydrochloric acid and germanium is subsequently separated from iron(III) and other co-precipitated elements by a single heptane extraction of germanium tetrachloride from 9̃.4 M hydrochloric acid. The extract is washed with 12 M hydrochloric acid to remove residual iron(III), then germanium is stripped with water and determined spectrophotometrically with phenylfluorone in a 1.4 M hydrochloric acid−0.002 M cetyltrimethylammonium bromide medium in the presence of ascorbic acid as a reductant for co-extracted chlorine. The apparent molar absorptivity of the complex is 1.71 × 10 4 l.mole −1.mm −1 at 507 nm, the wavelength of maximum absorption. Up to 5 mg of tin(IV), 10 mg of antimony(V) and tungsten(VI) and $ ̃ 50 mg of silica do not interfere. Germanium values are given for some Canadian certified reference ores, concentrates and iron-formation samples and for a metallurgical dust.

The analysis of beryllium and beryllium oxide—I: The determination of iron

The importance of beryllium and beryllium oxide to the atomic energy programme has necessitated the development of accurate methods of chemical analysis for the determination of metallic impurities. A method is presented for separating iron by extraction with tri- n-octylphosphine oxide followed by determination with 1:10-phenanthroline. The method is accurate to ±3% or ±3 micrograms of iron, whichever is greater. The accuracy and sensitivity could be increased by appropriate choice of sample weight, volume of extract, and/or cell length. Of the 68 elements investigated, 61 do not interfere in 10-mg amounts. No interference is caused by 5 mg of silicon, 1 mg of antimony, gallium, molybdenum, or tungsten, or 0.1 mg of tellurium or uranium. Only gallium, tellurium and silicon interfere without producing a warning turbidity in the coloured solution.