Simultaneous Determination Of Thorium Research Articles

Simultaneous Determination of Thorium and Uranium in Mineral Fertilizers by Inductively Coupled Plasma Optical Emission Spectrometry

The simultaneous determination of thorium and uranium in mineral fertilizers by inductively coupled plasma optical emission spectrometry (ICP OES) was optimized. The three-level factorial design was applied to optimize the operating conditions of radiofrequency power and nebulizer gas flow rate. The analytical method was specific and selective for both elements.

Fully automated lab-on-valve-multisyringe flow injection analysis-ICP-MS system: an effective tool for fast, sensitive and selective determination of thorium and uranium at environmental levels exploiting solid phase extraction

An on-line solid-phase extraction method linked to inductively coupled mass spectrometry (ICP-MS) has been developed for the determination of low levels of uranium and thorium in environmental samples. The hyphenation of lab-on-valve (LOV) and multisyringe flow injection analysis (MSFIA), coupled to an ICP-MS, allows the simultaneous determination of thorium and uranium in different types of environmental sample matrices achieving high selectivity and sensitivity levels. On-line separation and preconcentration of thorium and uranium are carried out by means of UTEVA resin. The potential of the LOV-MSFIA makes possible the full automation of the system by the on-line regeneration of the column. The limits of detection reached are 0.4 ng L−1 of uranium and 2.8 ng L−1 of thorium. The reproducibility of the LOV-MSFIA-ICP-MS is 1.7% of RSD. Moreover, a high sensitivity, a wide working range (0–200 μg L−1 for uranium and thorium) and an injection frequency up to 9 h−1 (depending on the sample volume) should be highlighted. Different water sample matrices (seawater, well water, freshwater, tap water and mineral water), a phosphogypsum sample with natural uranium and thorium content and a channel sediment reference material were satisfactorily analyzed with the proposed method.

Simultaneous determination of thorium and uranyl ions by optode spectra and chemometric techniques

A sensitive optode was fabricated from a recently synthesized ligand (triazene-1,3-di(2-methoxyphenyl)). Simultaneous determination of thorium and uranium in aqueous samples were performed by this optode in conjunction with partial least squares (PLS) and artificial neural network (ANN) techniques. The measured absorbances at 27 selected wavelengths were used for training. A PLS1 model with 4 and 3 latent variables for thorium and uranium respectively, a PLS2 model with 4 latent variables and a principal component ANN model (4-2-2) with linear transfer function after hidden and output layers were created. Relative error of prediction for PLS1, PLS2 and ANN models in synthetic mixtures were 7.40%, 7.12% and 5.04% respectively.

The Simultaneous Determination of Thorium, Niobium, Lead, and Zinc by Photon-Induced X-ray Fluorescence of Lateritic Material

A rapid method is presented for the simultaneous determinations of thorium, niobium, lead, and zinc in lateritic material from Cerro Impacto, Estado Bolívar, Venezuela. This technique uses a PDP—11/05 processor—based photon induced x-ray fluorescence system. The total variations of approximately 5% for concentrations of approximately 1 and 10% for concentrations of approximately 0.1% were obtained with only 500 s of fluorescent time. The values obtained by this method were in agreement with values measured by conventional flame atomic absorption spectroscopy for lead and zinc. The values for thorium measured were in agreement with the reported values for the reference materials supplied by NBL.

Simultaneous determination of thorium and uranium in ores and SRMs by instrumental neutron activation analysis

A procedure has been developed for the determination of thoirum and uranium in ores and geological materials. The technique is relatively simple, accurate and adaptable routinely. Gamma-ray peak interferences are discussed in detail and the usefulness of the multiple gamma-ray peak ratios in the determination of the purity of peaks has been explained. The precision and accuracy of the method have been determined by analysing IAEA and NBL Standard thorium/uranium ores.

Inorganic chromatography on cellulose. Part IX. The use of alumina and cellulose adsorbents for the determination of thorium and the simultaneous determination of thorium and uranium in minerals and ores

Inorganic chromatography on cellulose. Part IX. The use of alumina and cellulose adsorbents for the determination of thorium and the simultaneous determination of thorium and uranium in minerals and ores