Separations involving sulphides : Separation of platinum,gold, selenium,arsenic, rhenium and molybdenum from lead

It has been shown that it is possible to determine platinum, gold, selenium, arsenic, rhenium or molybdenum in the presence of lead with 2N sodium sulphide reagent but not tellurium, antimony and tin.     

Determination of antimony in concentrates, ores and non-ferrous materials by atomic-absorption spectrophotometry after iron-lanthanum collection, or by the iodide method after further xanthate extraction

Methods for determining trace and moderate amounts of antimony in copper, nickel, molybdenum, lead and zinc concentrates and in ores are described. Following sample decomposition, antimony is oxidized to antimony(V) with aqua regia, then reduced to antimony(III) with sodium metabisulphite in 6M hydrochloric acid medium and separated from most of the matrix elements by co-precipitation with hydrous ferric and lanthanum oxides. Antimony (>/= 100 mug/g) can subsequently be determined by atomic-absorption spectrophotometry, at 217.6 nm after dissolution of the precipitate in 3M hydrochloric acid. Alternatively, for the determination of antimony at levels of 1 mug/g or more, the precipitate is dissolved in 5M hydrochloric acid containing stannous chloride as a reluctant for iron(III) and thiourea as a complexing agent for copper. Then tin is complexed with hydrofluoric acid, and antimony is separated from iron, tin, lead and other co-precipitated elements, including lanthanum, by chloroform extraction of its xanthate. It is then determined spectrophotometrically, at 331 or 425 nm as the iodide. Interference from co-extracted bismuth is eliminated by washing the extract with hydrochloric acid of the same acid concentration as the medium used for extraction. Interference from co-extracted molybdenum, which causes high results at 331 nm, is avoided by measuring the absorbance at 425 nm. The proposed methods are also applicable to high-purity copper metal and copper- and lead-base alloys. In the spectrophotometric iodide method, the importance of the preliminary oxidation of all of the antimony to antimony(V), to avoid the formation of an unreactive species, is shown.     

Determination of antimony,bismuth, and zinc in environmental samples by atomic emission spectrometry

A procedure was developed for the atomic emission determination of antimony, zinc, and bismuth in bird and fish ash using thermochemical iodination reactions in a chamber electrode of an alternating current (ac) carbon arc. A mixture of cadmium iodide and carbon powder was used as an iodination agent. The relative standard deviation of the procedure was 10–15%. The minimum detection limit was 2.1 × 10⁻⁴, 7.5 × 10⁻⁵, and 1.2 × 10⁻⁴% for antimony, bismuth, and zinc, respectively.     

The determination of traces of antimony,tin and arsenic in cadmium by pulse polarography

Traces of antimony, tin and arsenic in cadmium products were determined by pulse polarography. Arsenic was distilled, while antimony and tin were precipitated as hydroxides with manganese dioxide as carrier; some lead was coprecipitated with tin, hence these elements were further separated by distillation. In all cases quantitative recoveries were obtained. Antimony(III) was determined in a hydrochloric acid-sodium hypophosphite mixture, tin(IV) in a hydrochloric-hydrobromic acid mixture and arsenic(III) in sulphuric acid as supporting electrolytes; for arsenic(III), methylene blue had to be added. A sample weight of 10 g and an end volume of 10 ml allowed the determination down to about 0.004 p.p.m. antimony, 0.006 p.p.m. tin and 0.003 p.p.m. arsenic in cadmium. Several synthetic samples and commercially available cadmium products were analysed.     

Some aspects of n-benzoylphenylhydroxylamine and cupferron reactions with tin,antimony and other selected elements

N-Benzoyl-N-phenylhydroxylamine (BPHA) and cupferron are compared in the liquid-liquid extraction of tin and antimony. As in their precipitation reactions tin(II) and tin(IV) behave similarly with BPHA and differently with cupferron. Both reagents behave similarly in extraction of antimony (III), except at high acidity when cupferron or its decomposition products prevent extraction which otherwise occurs into chloroform alone. Separations of Sn, Sb, As and Bi are discussed for extractions from hydrochloric and perchloric acid systems with BPHA. The tin product extracted with BPHA from dilute hydrochloric acid appears to be identical with that precipitated in gravimetric analysis; infrared spectral evidence shows the latter to contain tin(IV). Other precipitation reactions of BPHA in the presence of anions other than chloride and some solubility measurements are also reported.     

Analysis of main constituents of lead- and tin-base alloys by controlled potential electrolysis

The paper describes the successive electrolytic deposition by the controlled potential technique, of antimony, lead (+ copper) and tin in lead- or tin-base alloys, and of bismuth, antimony, lead and tin in bismuth-base alloys.     

Determination of volatile hydride-forming metals in steel by atomic absorption spectrometry

A scheme of analysis is presented for the determination of arsenic, antimony, bismuth, lead, selenium, tellurium and tin in steel by evolution of their volatile hydrides and subsequent atomic absorption spectrometry in an argon—hydrogen-entrained air flame. The method is rapid and applicable to a wide range of steels. Detection limits in steel of 1 p.p.m. for arsenic, antimony, bismuth, selenium and tellurium, 2 p.p.m. for tin and 7 p.p.m. for lead are reported. There is some interference in the determination of lead from copper and nickel, but the method could become a viable alternative to existing procedures in the determination of lead in steels of low alloy content, and in irons. Accuracy and precision data are presented.     

A microanalytical volumetric method for the determination of antimony in lead-base and tin-base alloys

Indications are given for the constructions of simple and efficient immersion filters and bicarbonate valves.The authors have elaborated a rapid and exact microvolumetric method for the determination of antimony in alloys based on lead or tin, containing up to 18% antimony.     

Determination of tin in titanium alloys

Tin-titanium alloys are becoming increasingly important; consequently a good method is needed for the determination of tin in this type of material. In this paper an accurate iodometric procedure is proposed for the determination. The sample is dissolved in sulfuric acid and the titanium oxidized with potassium permanganate. Tartaric acid is added and the tin precipitated with hydrogen, sulfide. The sulfide precipitate is dissolved in a mixture of sulfuric, perchloric and nitric acids and the solution evaporated to fumes of sulfuric acid. Water and hydrochloric acid are added, and the tin is reduced with lead and antimony trichloride and titrated with iodine. A study was made of the interfering elements that might be found in titanium alloys. The effect of antimony trichloride in reducing interference from copper was investigated. The method is recommended for titanium alloys containing 0.05 to 5.0 per cent. tin.     

Na2EDTA滴定法测定粗二氧化碲中铅含量

建立了用氢溴酸消除锑、砷、锡干扰,用硫酸将铅形成硫酸铅沉淀,再用EDTA络合滴定法测定粗二氧化碲中铅量的方法。试样用硝酸、盐酸溶解,用硫酸沉淀铅,氢溴酸消除锑、砷、锡的干扰后,过滤分离其他共存元素,以乙酸-乙酸钠缓冲溶液溶解硫酸铅沉淀,在pH=5.0～6.0时,以二甲酚橙作指示剂,用Na_2EDTA溶液滴定溶液中铅含量。实验结果表明,氢溴酸加入量为15mL,酒石酸加入量为10mL,沉淀体积为50～60mL,沉淀时间1h以上时,方法相对标准偏差(RSD)在0.10%～1.1%,加标回收率为97.1%～102%,满足粗二氧化碲中铅量的生产控制检测要求。     

Titrages “thermochimiques” par formation de fluorures complexes de fer,aluminium, antimoine,etain et plomb

A thermochemical study of the titration of aluminium, iron, copper, lead, tin and antimony salts with sodium fluoride is described. The destruction of fluoride cumplexes by boric acid has been studied. The measurement apparatus consists of two thermistors and a bridge. Clear breaks were obtained for iron, aluminium, copper and lead but no separation of iron and aluminium was possible. The action of boric acid also gave clear breaks in the curves.     

Separations involving sulphides : Separation of bismuth,cadmium and indium from various other elements that form thiosalts

It has been shown that 2N sodium sulphide reagent can be successfully used in separating tellurium, molybdenum, antimony or rhenium from bismuth., platinum, gold, selenium, rhenium, arsenic, molybdenum or tellurium from cadmium; platinum, gold, selenium, rhenium, arsenic, molybdenum, tellurium or antimony from indium.It is not possible to separate quantitatively arsenic, platinum, gold or selenium from bismuth; antimony from cadmium; and tin from bismuth, cadmium or indium.     

火焰原子吸收光谱法直接测定锡阳极泥中的银

建立了火焰原子吸收光谱法(FAAS)测定锡阳极泥中银含量的方法。文章考察了不同的测定介质、酸度对测定结果的影响。实验结果表明在选定条件下,锡阳极泥中的锡、锑、铅等杂质不干扰银的测定。方法加标回收率在99.2%~103%,精密度实验结果表明,相对标准偏差(RSD,n=11)均小于4%。操作过程简单,能满足生产的需要。     

Rapid method for the separation and determination of bismuth,antimony, and tin by controlled cathode electroanalysis

A study was made of the separation and determination of bismuth, antimony, and tin by electrochemical means, using controlled cathode potential. The effects of electrolyte composition, cathode potential, and temperature were investigated with respect to separations of the three metals and degree of recovery of each. Best results were obtained by use of an electrolyte containing sulfate and citrate. A procedure was devised which would serve for rapid analysis for bismuth, antimony and tin in the form of mixtures and alloys     

A radiochemical neutron activation analysis method for the determination of tin,arsenic, copper and antimony for the forensic comparison of bullet lead specimens

Trace element characterization of bullet lead by instrumental neutron activation analysis (INAA) is hampered by the high spectral background due to antimony, normally present in high concentration in bullet lead. Tin is indicated to be a very useful element for characterization purposes. Beta-active¹²¹Sn is a suitable nuclide for quantitation of tin provided it is separated in high radiochemical purity. A radiochemical procedure capable of determining tin down to 10 ppm in bullet lead, a sequential procedure for its determination along with copper, arsenic and antimony and the application of this procedure for the determination of the contents of these elements in various bullet leads are described. This method has been applied to a “Rhinoceros shoot-out” case, referred to our laboratory.     

Separations involving sulphides : Separation of rhenium and antimony from mercury

It has been shown that it is possible to estimate rhenium or antimony in the presence of mercury by decomposing their thiosalts but not platinum, gold. selenium and tin.     

复杂高铋物料中铅的Na2EDTA滴定法测定

复杂高铋物料中,铋、砷、锑、锡四元素含量高且共存时会影响铅的测定。特别是铋含量高时对铅的测定影响大。实验用EDTA—酒石酸联合掩蔽铋、砷、锑、锡,在稀硫酸介质中以硫酸钾为沉淀剂,使铅生成硫酸铅钾复盐沉淀而与铋、砷、锑、锡、铁、铜、锌、铝、钴、镍等干扰离子分离,沉淀以乙酸-乙酸钠浸取,二甲酚橙为指示剂,Na2EDTA滴定法测定铅。试验进一步优化了测定条件,确定最佳条件：硫酸（1 1）加入量为7mL、硫酸钾用量为5g、煮沸时为5min、沉淀陈化时间为2h、EDTA 50g/L 加入量为10mL、酒石酸用量为0.5g,铅的回收率99.70% ～100.65%。将实验方法应用于测定复杂高铋物料中铅,标样BY0111-1与给定值一致,相对标准偏差（n=11）RSD 0.20%～0.23%,满足生产测试要求。     

Redox substoichiometry in isotope dilution analysis

The oxidation reaction of antimony(III) with potassium dichromate has been investigated radiometrically. The quantitative oxidation of antimony(III) was found to be not disturbed even in large amounts of tin(IV). On the basis of these results the redox substoichiometric isotope dilution analysis using potassium dichromate as the oxidizing agent was proposed for the determination of antimony in metallic tin. The antimony content of 1.22±0.05 μg in metallic tin (10 mg) was determined without separation of the matrix element.     

Separation of gallium, indium and thallium by extraction with n-octylaniline in chloroform

Extraction of gallium(III), indium(III) and thallium(III) with n-octylaniline in chloroform at various concentrations of hydrogen halide acids (HCl, HBr, HI) has been studied and a scheme for their separation proposed. The procedure can be successfully applied to the separation and determination of gallium in presence of mercury, bismuth, manganese, zinc and lead; indium in presence of bismuth, antimony, lead, mercury, cadmium and zinc; and thallium in presence of mercury, cadmium, manganese, aluminium, tin and antimony. The advantage of the method is that the reagent can be recovered for reuse. The method is simple, rapid, and effects clear-cut separation.     

Synthesis and spectroscopic characterization of arsenic(III), antimony(III), bismuth(III), tin(II) and lead(II) dithiocarbamate adducts

The complexes of arsenic(III), antimony(III), bismuth(III), tin(II) and lead(II) with monomethylsubstituted piperidinodithiocarbamates of general formula M(Rdtc)₃ and M(Rdtc)₂ have been prepared and characterized by spectroscopic methods. The results of the spectroscopic studies indicate that the dithiocarbamate ligands are always bidentate, in both the 1:3 and the 1:2 complexes. All the complexes are nonconducting in DMF solution. The thermal behaviour of the complexes has been investigated by TG and DTG techniques. The molecular weight determinations indicate that the trisdithiocarbamates of arsenic and antimony are monomeric, while the bismuth trisderivatives tend to dimerize: polymeric structures can be suggested for the tin(II) and lead(II) compounds.