Polarographic determination of traces of zirconium in ores by use of complex-forming compounds adsorbable at the dropping mercury electrode

A polarographic method is proposed for the determination of trace zirconium down to the 5 x 10(-9)M level, based on the adsorption of the complex of zirconium with oxalic acid + cupferron + diphenylguanidine at the dropping mercury electrode in sodium acetate-acetic acid solution (pH 5.7). Under optimum conditions the wave-height is proportional to the concentration of zirconium in the range from 0 to 0.4 mug ml . The serious interference from titanium(IV) can be effectively eliminated by solvent extraction with 3% tri-n-octylamine from lN sulphuric acid and stripping with 0.1 M perchloric acid-lM hydrochloric acid-2M nitric acid mixture. The mechanism giving rise to the wave for the zirconium complex has been investigated. The method has been applied to the determination of trace zirconium in ores and ceramics.     

Sequential liquid-liquid extraction graphite furnace atomic absorption spectrometric (GFAAS) and spectrophotometric determination of zirconium(IV) with calixarene hydroxamic acid

A new calixarene hydroxamic acid, 25,26,27,28-tetrahydroxy-5,11,17,23-tetrakis (N-p-chlorophenyl) calix[4]arene hydroxamic acid (CPCHA) is synthesized and used for the extraction and graphite furnace atomic absorption determination of zirconium(IV). The extract is also determined spectrophotometrically as CPCHA-SCN complex having maximum absorbance at 447 nm with molar absorptivity 9.4x10(3) l mol(-1) cm(-1). The Beer's law obeys in the range of 1.0-9.5 ppm of zirconium. The graphite atomic absorption (GFAAS) increases the sensitivity by about 50 folds. The method is applied to the trace determination of zirconium(IV) in standard samples.     

N_(1923)萃取锆性质的研究及其应用

本实验研究了酸性介质中N_(1923)对锆的萃取行为,测定了萃合物中胺与金属离子锆的组成比为2:1,并拟定了应用于测定矿样中锆的方法。     

Solid phase extraction of zirconium as arsenazo(III) complex on agar and spectrophotometric determination

A new solid phase extraction method for the separation and determination of zirconium using agar as an adsorbent is described. The method is based on the adsorption of zirconium as arsenazo(III) complex on agar in a mini-column, elution with sulfuric acid-acetone mixture and determination by spectrophotometry. The effect of different parameters such as pH, concentration of the reagent, eluting reagent, and volume of the sample, amount of the adsorbent and interfering ions was investigated. The calibration graph was linear in the range of 5?C300 ng ml^?1 of zirconium under optimum conditions. The limit of detection based on 3S_b was 1.3 ng ml^?1 and the relative standard deviation (R.S.D) for ten replicate measurements of 15 and 200 ng ml^?1 of zirconium was 3.7 and 1.8%, respectively. The method was applied to the determination of zirconium in water and soil samples.     

电感耦合等离子体发射光谱法测定二硼化锆中26种杂质

建立微波消解样品,电感耦合等离子体发射光谱法测定二硼化锆中26种杂质元素含量的方法。根据二硼化锆的化学组成对杂质检测的影响,确定了各元素最佳分析线;通过考察不同浓度的锆基体对待测元素的影响来确定最佳锆基体浓度;通过萃取法分离硼元素,消除硼对杂质检测的干扰;采用基体匹配法、多谱拟和技术消除了锆基体的干扰。在选定的仪器工作条件下,各待测元素的质量浓度与信号强度成良好的线性关系,线性相关系数均大于0.999。测定结果的相对标准偏差不大于6%(n=11),样品加标回收率为94%~101%。该方法操作简便,测定结果准确,可用于二硼化锆中26种杂质元素的测定。     

Zirconium and hafnium determination by energy dispersive X-ray fluorescence with solid phase preconcentration

Two preconcentration methods has been developed for simultaneous determination of zirconium and hafnium by energy dispersive X-ray fluorescence (EDXRF). The first method is a liquid-solid extraction procedure with the use of an anionic exchange resin modified with xylenol orange. The second is a precipitation procedure carried out in the presence of lanthanum. Both methods permit significant enhancement of sensitivity in comparison with direct measurement in the aqueous phase. The applicability of both procedures for the preconcentration of Zr and Hf prior to their determination by EDXRF was demonstrated by analyzing synthetic mixtures and a sample of zirconium ore. The results obtained with the use of the modified resin show relative standard deviation of about 4% and good agreement with those obtained by spectrographic analysis.     

Extractive separation of group IVB elements: analysis of alloy samples

A method is proposed for the extraction and mutual separation of quadrivalent titanium, zirconium and hafnium from hydrochloric acid using triphenylphosphine oxide dissolved in toluene as an extractant. The optimum conditions for the extraction and separation have been evaluated from critical study of acid concentration, extractant concentration, period of equilibration and effect of diluent. The effect of foreign ions on the extraction and determination is also discussed. The probable composition of the extracted species has been deduced from logD-logC plots. The method affords mutual separation of titanium, zirconium and hafnium and is applicable to the analysis of alloy samples.     

Complexometric determination of magnesium in nodular cast iron and alloyed cast iron roll samples

A complexometric method for the determination of magnesium in nodular cast iron, alloyed cast iron and roll samples has been developed. The bulk of the iron is removed by ether extraction and the phosphate as zirconium phosphate. The other elements are removed by extraction with dithiocarbamate into chloroform. Magnesium is then titrated with EDTA at pH 10, with Eriochrome Black T as indicator. Calcium interferes, but is very rarely present in such cast iron samples.     

Spectrophotometric determination of zirconium, uranium, thorium and rare earths with arsenazo III after extractions with thenoyltrifluoroacetone and tri-n-octylamine

A method is described for the spectrophotometric determination of microgram amounts of zirconium, uranium(VI), thorium and rare earths with Arsenazo III after systematic separation by extraction. First zirconium is extracted into a xylene solution of thenoyltrifluoroacetone (TTA) from about 4M hydrochloric acid. Uranium(VI) is then extracted into a xylene solution of tri-n-octy lamine from about 4M hydrochloric acid. Thorium is next extracted into TTA solution at pH about 1.5, and finally rare earths are extracted into TTA solution at pH about 4.7. Each metal is back-extracted from the organic phase before determination.     

A highly selective procedure for the spectrophotometric determination of aluminium with 8-hydroxy-quinoline and its application to the determination of

Aluminium, hydroxyquinolate can be quantitatively extracted by chloroform from an ammoniacal solution containing hydroxyquinoline, complexone and cyanide. Likewise extracted are titanium, vanadium, tantalum, niobium, uranium, zirconium, gallium, antimony, bismuth, indium and traces of beryllium. Aluminium can be separated from the first five elements by an extraction in ammoniacal solution containing hydrogen peroxide.Zirconium, gallium, bismuth and antimony can be eliminated by a cupferron extraction and indium by extraction with diethyldithiocarbamate. Beryllium is eliminated by performing an extraction with hydroxyquinoline at pH 5. The proposed method enables a practically specific photometrical determination of aluminium. Applications are given of the determination of trace and higher amounts of aluminium in steels, non-ferrous alloys and in glass.     

Spectrophotometric determination of scandium with arsenazo

Arsenazo is used for the spectrophotometric determination of scandium in the range 10 to 50 μg. The absorbance is measured at 570 mμ and pH 6.1. A method is proposed for the successive determination of scandium and thorium. Scandium is separated from magnesium, calcium, rare earths, zirconium, fluoride, phosphate, and some other metals by extraction with TTA in xylene. Copper, aluminum, and iron(III) are removed by 8-quinolinol-chloroform extraction. Uranium(VI) is removed by anion exchange using hydrochloric acid. Thorium is separated from scandium by anion exchange using nitric acid.     

Use of organic reagents in inorganic analysis

Summary Seven anilic acids obtained from phthalic anhydride and aromatic amines were studied for their quantitative precipitating action on zirconium. The anilic acids from p-toluidine, m- and p-nitranilines and -naphthylamine were only found effective for the quantitative determination of zirconium. Zirconium is completely precipitated at a little lowerph value with these reagents, than thorium. Compositions of the zirconium salts of these acids are not definite, so ignition of the precipitates to zirconia is necessary. Separation of zirconium from common elements like Cu, Al, Cr, Mg, Zn, Ti etc. may be done with ease. But for iron, uranium, cobalt and nickel double precipitation is essential. A considerable amount of thorium has been separated from zirconium, by extraction with amylacetate.     

Determination of uranium in zircon

A routine fluorimetric procedure is described for the determination of trace amounts of uranium in zircon. It employs the direct extraction of uranyl nitrate with ethyl acetate using phosphate as a retainer for zirconium. Submicrogram amounts or uranium are separated in the presence of 100,000 times the amount of zirconium. The modified procedure has been worked out using synthetic mixtures of known composition and zircon. Results of analyses have an accuracy of 97–98% of the contained uranium and a standard deviation of less than 2.5%.     

Microdosage du cobalt dans le ,,zirconium reactor-grade''

A method is described for the separation and determination of cobalt in 100 mg reactor-grade zirconium. Separation is effected by means of an ion-exchange resin. After elution, the cobalt is purified by extraction with dithizone and determined spectrophotometrically with the help of nitroso-R-salt. With this method a content of 0.0003% can be determined with an accuracy of ±4%.     

电感耦合等离子体质谱法测定地质样品中银研究进展

应用电感耦合等离子体质谱（ICP-MS）测定地质样品中银时,锆、铌等元素干扰银的测定,造成准确度低、测定偏差大。采用银的富集、王水偏提取和化学分离法等方法可对干扰元素预分离,从而准确测定样品中银;而应用干扰校正方程及碰撞/反应池（CRC-ICP-MS）、膜去溶（DSN-ICP-MS）、激光剥蚀（LA-ICP-MS）和高分辨质谱（HR-ICP-MS）等新技术,能够更加方便、准确测定地质样品中银。     

Determination of niobium, titanium and zirconium by high-frequency plasma torch emission spectrometry and its application to steel

The basic conditions for the determination of niobium, titanium and zirconium with an argon plasma and a Hitachi UHF Plasma Spectrascan operated at 2450 MHz and 450 W maximum output, have been established. The niobium 405.89-nm, titanium 365.35-nm and zirconium 339.19-nm lines gave detection limits of 0.5, 0.1 and 2.0 p.p.m., respectively, when pure solutions were used. Effects of gas flow rates, high-frequency output and concentration of acids were examined. In applications to steel, titanium was determined without prior chemical separation from iron at the 499.95-nm line, whereas niobium and zirconium could not be determined in the presence of large amounts of iron. When a cupferron precipitation method followed by extraction of iron with methyl isobutyl ketone was applied, satisfactory results were obtained.     

The differentiation of submicrogram amounts of inorganic and organomercury in water by flameless atomic absorption spectrometry

The basic conditions for the determination of niobium, titanium and zirconium with an argon plasma and a Hitachi UHF Plasma Spectrascan operated at 2450 MHz and 450 W maximum output, have been established. The niobium 405.89-nm, titanium 365.35-nm and zirconium 339.19-nm lines gave detection limits of 0.5, 0.1 and 2.0 p.p.m., respectively, when pure solutions were used. Effects of gas flow rates, high-frequency output and concentration of acids were examined. In applications to steel, titanium was determined without prior chemical separation from iron at the 499.95-nm line, whereas niobium and zirconium could not be determined in the presence of large amounts of iron. When a cupferron precipitation method followed by extraction of iron with methyl isobutyl ketone was applied, satisfactory results were obtained.     

Determination of oxygen in zirconium by the platinum flux technique

The platinum flux technique, well established for the determination of oxygen in titanium, was successfully applied to the analysis of zirconium for its oxygen content after a systematic study of the optimum experimental conditions. The extraction of oxygen was complete in 20 min in the temperature range of 1850 to 2100° with a ratio of flux to sample of about 4.5:1 to 8:1. Statistical analysis of the results on a homogeneous sample gave a standard deviation of 0.0038 weight % and a coefficient of variance of 2.9%atalevelof 0.131 weight % of oxygen in zirconium. The recommended experimental conditions are a 0.1-g sample, a 5:1 flux-to-sample ratio, and 20 min extraction at 1900°–1950°.     

Extraction and spectrophotometric determination of cobalt(ii) with 2-thenoyltrifluoroacetone

The rapid extraction and simultaneous spectrophotometric determination of mg amounts of cobalt(II) by means of 2-thenoyltrifluoroacetone is described. The yellow cobalt(II)-TTA chelate solution in acetone-benzene obeys Beer's law at 430 mμ over the range 12 to 51 μg of cobalt(II) per ml. At pH 5.1–6.8 a single extraction with 0.15 M TTA in acetone is satisfactory. The system is stable for 96 h. Silver, zirconium, strontium, thorium, zinc, lead(II) and mercury(II) do not interfere.     

Sorption-spectrophotometric determination of zirconium and chromium(VI) from a single sample on a two-layer support using Arsenazo III and 1,5-diphenylcarbazide

The possibility of the sorption-spectrometric determination of zirconium(IV) and chromium(VI) from a single sample using a two-layer support made of polyacrylonitrile fiber filled with a PANF-KU-2 cation exchanger and PANF-AV-17 anion exchanger is studied. After sorption zirconium is determined with Arsenazo III on PANF-KU-2 and chromium is determined with 1,5-dipehnylcarbazide on PANF-AV-17. The sorption of zirconium and chromium is studied in the dynamic mode from solutions of HCl, HNO₃, and H₂SO₄ and the optimal conditions of the simultaneous sorption of zirconium on PANF-KU-2 and chromium on PANF-AV-17 from 0.25 M HCl is chosen. Diffuse reflection spectra of zirconium and chromium complexes have are on the solid phase and the conditions of zirconium determination are optimized. Calibration curves are linear in the range of zirconium and chromium concentration 0.005–0.025 μg/mL; the detection limits are 0.002 μg/mL. The selectivity of zirconium and chromium determination is tested in the presence of interfering ions. A procedure is developed for their determination from a single sample at zirconium to chromium ratios from 3: 1 to 1: 3.