The micro volumetric determination of uranium with application to bismuth base alloy analysis

The macro volumetric method for the determination of uranium by titration against standard ceric sulphate after reduction on a lead column has been successfully applied on the micro scale Microgram amounts of uranium can be determined by this method, the lowest amount determinable being about 1 microgram. The procedure is accurate to within ±1% at the 100 μg level of uranium Although bismuth and iron cause difficulty, there is no interference from zirconium or thorium.This method for uranium has been applied to the analysis of bismuth base alloys containing uranium in concentrations from 0.005 to 0.1% by weight.     

Sensitive spectrophotometric determination of traces of zirconium with 2-(6-bromo-2-benzothiazolylazo)-5-diethylaminophenol in the presence of sodium lauryl sulphate

A simple and highly sensitive procedure for spectrophotometric determination of zirconium has been developed. At pH 4.6, zirconium reacts with 2-(6-bromo-2-benzothiazolylazo)-5-diethylaminophenol in the presence of sodium lauryl sulphate to form a red-violet complex, which has an absorption maximum at 520 nm. The molar absorptivity at 520 nm is 4.4 × 10⁵ 1.mole⁻¹ .cm⁻¹. Beer's law is obeyed for 0.25–1.50 μg of zirconium in 25 ml of solution. The method has been used in the determination of zirconium in aluminium alloy and steel samples.     

Selective preconcentration and determination of tributyltin in fresh water by electrothermal atomic absorption spectrometry

A rapid and simple method for separation and determination of tributyltin (TBT) in mineral and tap water is described. The procedure is based on the selective retention of TBT by a chelating resin, Amberlite XAD-2 impregnated with tropolone. The addition of 0.8% sulfuric acid to the water sample leads to the retention of TBT by the resin while monobutyltin (MBT), dibutyltin (DBT) and inorganic tin remain in solution. TBT is eluted with methyl isobutyl ketone (MIBK) obtaining a preconcentration factor of 80. Tin concentration is determined by ETAAS using zirconium coated tubes. Multi-injection and hot injection techniques are used in order to enhance the sensitivity of the method. A detection limit of 14.4 ng L(-1) is achieved with recoveries near to 100%. The procedure has been successfully applied to TBT determination in various fresh water samples.     

Radiochemical separation by inorganic ion exchanger and determination of cesium in complex matrices by thermal neutron activation analysis

A rapid and selective method has been developed for radiochemical separation, and determination of Cs in complex matrices by thermal neutron activation analysis. Batch adsorption of ¹³⁴Cs was carried out on zirconium phosphate ion exchanger. A large number of samples of the ore have been analysed for their Cs content and the results are discussed.     

锆-EDTA-(口底)唑体系混配型络合物的分光光度法研究及其应用

本文研究了锆-EDTA-(口底)唑混配型络合物的显色条件,表明在pH5.6-6.6形成了Zr(Ⅳ):EDTA:(口底)唑=1:1:1的稳定络合物,ε=2.81×10⁴(λ_max=503nm);锆在0-50微克/25毫升遵守比耳定律。并测定了镍基高温合金及铝镁合金中的微量锆,得到了满意的结果。     

Determination of Homologue Imidazolium Ionic Liquid Cations by Ion Chromatography Using a Carboxyl Acid Cation-Exchange Column with Direct Conductivity Detection

An investigation into the determination of four imidazolium ionic liquid cations by ion chromatography using a carboxyl acid cation exchange column and direct conductivity detection was carried out. This research has developed a simple, selective, and accurate ion chromatographic method for separation of imidazolium ionic liquid cations. Detection limits (S/N = 3) for the cations were 3.2–24.3 mg/L. Relative standard deviations (RSD, n = 5) for peak areas were less than 1.6%. The method has been successfully applied to the determination of two ionic liquids synthesized by organic chemistry lab.     

The Determination of Sodium in Alumina Using a Sodium Selective Ion Electrode

Abstract

A method has been developed for the determination of sodium in alumina using a selective ion electrode. The alumina sample is dissolved in ammonium hydrogen fluoride in platinum crucibles or sintered with boric acid using either platinum, nickel, or zirconium crucibles. Either dissolution technique completely extracts all available sodium. After dissolution, and in the presence of citrate to prevent aluminum hydroxide precipitation, the pH is adjusted to 8.7 with ammonium hydroxide, and the sodium concentration is determined by a sodium selective ion electrode.     

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.     

Selective, stability-indicating assay of the major ipecacuanha alkaloids, emetine and cephaeline, in pharmaceutical preparations by high-performance liquid chromatography using spectrofluorimetric detection

A selective high-performance liquid chromatographic procedure has been developed for the determination of the major Ipecacuanha alkaloids, emetine and cephaeline, in a number of linctus and pastille preparations. The reversed-phase chromatographic procedure uses an octadecyl-bonded column with a mobile phase of aqueous methanol containing an ion-pairing reagent. A spectrofluorimetric detector is used for increased sensitivity and selectivity. Sample preparation is simple, involving either straight dilution for linctus formulations or simple dissolutions for pastilles. The procedure has been shown to be stability-indicating. Validation studies, to show that the method is precise, accurate and rectilinear, have been carried out on four linctus formulations and two pastille formulations. The method has been used to determine both emetine and cephaeline at levels as low as 5 micrograms/g in formulations.     

Tartrazine,a new selective reagent for zirconium

A new method for determining zirconium is described, in which tartrazine serves as reagent. The precipitate can be ignited to ZrO₂ or weighed as the complex. The reagent appears to be very selective, and can be used for the determination of zirconium in alloys and ores.     

Mandelic acid and halogen-substituted mandelic acids as reagents for the determination of zirconium

o-, m-, and p-Fluoro- and -trifluoromethylmandelic acids have been prepared and an assessment made of their value as précipitants for zirconium. Though the p-derivatives are satisfactory there are no obvious advantages in their use. Direct weighings of zirconium mandelate and p-bromomandelate, about which there have been conflicting reports in the literature, have been investigated also. P-Bromomandelic acid has been used successfully for the determination of amounts of zirconium oxide between 3 and 50 mg per 100 ml but ignition of the precipitate to zirconium oxide is necessary. Of the acids examined, mandelic itself gives the only precipitate which is almost constant and stoichiometric in composition. The composition of this compound, however, varies slightly with the amount of zirconium present in the solution under test, and though an overall empirical factor can be applied its use is recommended only if a high order of accuracy is not required. If a series of determinations in a narrow range is to be carried out by direct weighing of zirconium mandelate, more accurate results might be obtained by determination of the appropriate factor for that range.     

Polarometrische bestimmung von zirkonium(IV) mit tartrazin

A new polarimetric procedure has been developed for the rapid determination of zirconium in the presence of tartrazin as reagent This determination is possible in the presence of uranium.     

Sorption-spectroscopy determination of zirconium on a PANV-KU-2 fibrous ion exchanger using Arsenazo III

The sorption and complexation of zirconium with Arsenazo III have been studied on a polyacry-lonitrile fibrous material filled with strongly acidic KU-2 cation exchanger in strongly acidic media. The optimal conditions have been chosen for the sorption-spectrophotometric and test determination of zirconium by diffuse reflection spectroscopy or visual testing. The limit of zirconium detection is 0.02 ??g/mL. The procedure was tested in the analysis of model solutions of ammonium molybdate and vanadate and copper chloride using the standard addition method.     

An internal standard method for the determination of tin and tungstein in cassiterite by photon activation analysis

A method is described for the simultaneous determination of tin and tungsten in cassiterite ores by photon activation analysis using both elements and zirconium and zinc as internal standards. By using a 15-MeV photon beam, some interfering reactions with higher threshold energies can be eliminated. Thus the data processing becomes simpler and more accurate. The proposed procedure can be used for the routine analysis of tin and tungsten in cassiterite samples.     

Analysis of Erythromycin II. Determination of Erythromycin in Human Blood Serum by Competitive Displacement of [14C]-Erythromycin from E. Coli Ribosomes

Abstract

A sensitive and selective method for the determination of erythromycin in human blood serum, in the range of 0.1 to 1.0 μg/ml, is described. The procedure is based on extraction of drug into ether and competitive displacement of [¹⁴C]-erythromycin from E. coli ribosomes. The method provides accurate, precise and rapid analyses and should be readily adaptable to bioavailability studies with erythromycin and its salts in man.     

Spectrophotometric determination of selenium with 6-amino-1-naphthol-3-sulphonic acid (J-acid) and its application in trace analysis

A selective procedure for spectrophotometric determination of selenium with 6-amino-1-naphthol-3-sulphonic acid (J-acid) is described. In acidic conditions selenium forms a yellow complex with J-acid which has an absorption maximum at 392 nm. The molar absorptivity is 1.48 x 10(4) 1 mol(-1)cm(-1). Beer's law is obeyed for selenium in the range of 0.08-0.8 mg/1. The method has been applied to the determination of trace amounts of selenium in water, polluted water, plant material and steel plant dust. The proposed method is sensitive, rapid, simple and accurate.     

Spectrophotometric study of the reaction of zinc with O-hydroxybenzenediazoaminoazobenzene and its application

A highly sensitive and selective procedure for spectrophotometric determination of zinc has been developed. At pH 10.6, in the presence of emulsifier p-octylpolyethyleneglycol phenylether (OP), zinc forms an orange-red complex with o-hydroxybenzenediazoaminoazobenzene (HDAA) which has an absorption maximum at 525 nm. The molar absorptivity is 1.50 x 10(5) 1.mole(-1).cm(-1). Beer's law is obeyed for zinc in the range 0-13 mug/25 ml. The method has been applied to the spectrophotometric determination of trace amounts of zinc in aluminium alloy and in human hair. The proposed method is simple, rapid and accurate. No heating or separation is required.     

3-Hydroxy-2-(2"-Thienyl)-4H-Chromon-4-one as a Spectrophotometric Reagent for the Trace Determination of Zirconium in an Aqueous Phase

A rapid, simple, selective, and sensitive method for the trace determination of zirconium has been developed based on the reaction of 3-hydroxy-2-(2"-thienyl)-4H-chromon-4-one in an hydrochloric acid medium to form a yellow–colored complex which is rendered water soluble by the micellar action of Triton X-100 and measured at 415 nm. Most of the metal ions do not interfere with the determination. Beer's law is obeyed in the concentration range 0–2.0 g/mL and the molar absorptivity of the complex is 2.73 × 10⁴L mol^–1cm^–1; Sandell's sensitivity is found to be 0.0034 g cm^–2. The method has been applied for the determination of zirconium in various samples, and satisfactory results have been obtained.     

Application of the isotope dilution technique for Zr determination in an irradiated cladding material by multiple collector-inductively coupled plasma mass spectrometry

The determination of ⁹³Zr concentration, a long-lived radionuclide present in spent nuclear fuel and in the structural components of nuclear reactors, is a major issue for nuclear waste disposal purpose and to validate neutronic calculation codes. To measure ⁹³Zr concentration in irradiated cladding material with a high precision, an analytical method based on the use of multiple collector-inductively coupled plasma mass spectrometer (MC-ICPMS) combined to isotope dilution technique was developed. First a radiochemical separation of zirconium from a zircaloy sample (a zirconium alloy used as a cladding material for nuclear fuel elements), has allowed to obtain a very pure zirconium fraction with no potential isobaric interferences for mass spectrometric measurements. Then as the determination of all zirconium isotope ratios in the sample is necessary for the isotope dilution method, a MC-ICPMS procedure was developed to perform these precise measurements. Finally, the determination of ⁹³Zr concentration in the same sample was performed, after preparation and calibration of a ⁹⁶Zr spike solution. The uncertainties obtained on isotope ratios of zirconium by MC-ICPMS were in the order of 0.1%. The final uncertainty obtained on the ⁹³Zr concentration in the nuclear material used and after chemical purification was lower than 0.6%.     

Ultratrace-level radium-226 determination in seawater samples by isotope dilution inductively coupled plasma mass spectrometry

An improved and novel sample preparation method for ²²⁶Ra determination in liquid samples by isotope dilution inductively coupled plasma sector field mass spectrometry using laboratory-prepared ²²⁸Ra tracer has been developed. The procedure involves a selective preconcentration achieved by applying laboratory-prepared MnO₂ resin followed by cation exchange chromatographic separation. In order to completely eliminate possible molecular interferences, medium mass resolution (R = 4,000) combined with chemical separation was found to be a good compromise that enhanced the reliability of the method. The detection limit of 0.084 fg g⁻¹ (3.1 mBq kg⁻¹) achieved is comparable to that of the emanation method or alpha spectrometry and is suitable for low-level environmental measurements. The chemical recovery of the sample preparation method ranged from 72 to 94%. The proposed method enables a rapid, accurate and less labor-intensive approach to routine environmental ²²⁶Ra determination than the radioanalytical techniques conventionally applied.