Determination Of Tellurium Research Articles

Tellurium determination by three modes of instrumental neutron activation analysis in aerosol filters and trap solutions for the simulation of a severe nuclear accident

Tellurium belongs to the elements not frequently determined by neutron activation analysis (NAA) or other analytical methods. We present results of a new methodological study using three independent modes of instrumental NAA (INAA) using the 123mTe, 131Te and 131I radionuclides. We compare the results obtained in terms of accuracy, precision and limits of detection (LOD). We utilized the INAA procedures tested for the tellurium determination in aerosol filters and trap solutions in a model experiment aimed at reducing the knowledge gap concerning the behaviour of 132Te, a radiologically significant fission product, which constitutes a considerable health risk towards the public in case of its release in a severe nuclear power plant accident. We found that the nuclear reaction 130Te(n,γ)131Te and gamma-ray spectrometric measurement of 131I, a descendant of 131Te, is the most sensitive way of Te determination by INAA providing as low LOD values as 0.15 µg of Te in the Teflon aerosol filters and 0.22 µg mL-1 in the 0.1 M NaOH trap solutions. The three independent INAA modes allowed employing the self-verification principle of INAA for increasing the trustworthiness of our results. Finally, we also point to the indispensable role of the non-destructive feature of INAA for assay of samples, such as Teflon aerosol filters, that are difficult to be analysed by other analytical methods requiring complete sample destruction without analyte losses.

Cobalt ion-enhanced photochemical vapor generation in a mixed acid medium for sensitive detection of tellurium(iv) by atomic fluorescence spectrometry

Cobalt ion-assisted enhancement of photochemical vapor generation in a mixed acid medium was used for sensitive determination of tellurium(iv) by atomic fluorescence spectrometry.

Optimization of T-shape slotted quartz tube with exit holes-atom trap-flame atomic absorption spectrophotometry system for the accurate and sensitive determination of tellurium in tap water.

Tellurium has been widely used in industrial processes and daily life products, and can cause serious health problems upon exposure. Therefore, determination of tellurium in real-life samples is very crucial. In this study, an accurate, environmentally friendly, and inexpensive analytical method was developed to determine trace levels of tellurium in water samples. To lower the detection limits, system parameters including flame type, acetylene flow rate, slotted quartz tube (T-SQT) height, and trapping period were optimized. Under the optimum conditions, the limit of detection (LOD) and quantification (LOQ) were calculated as 14.1ng/mL and 47.1ng/mL, respectively. For recovery studies, the optimized T-SQT-AT-FAAS method was applied to tap water samples to determine trace levels of tellurium and recovery results were found between 91.1 and 111.3%. Relative standard deviation value (%RSD) of the developed method was found to be less than 5.0% even for the lowest concentration in calibration plot, specifying good accuracy and high applicability of the method for water samples. Graphical abstract .

A general strategy for the voltammetric trace determination of tellurium in geochemical and environmental matrices after arsenic coprecipitation and critical assessment of digestion schemes

Environmental contextAmong chemical elements classified as elements of strategic importance, tellurium is rapidly becoming an emergent contaminant. There is, however, no accurate and sensitive method for measuring tellurium concentrations in environmental and geological samples (e.g., soils, sediments), and thus it is not possible to determine whether an ecosystem is being polluted by human activities. This study provides a reliable answer to this problem. AbstractA general method is proposed for the determination of tellurium in environmental and geochemical samples. Samples may be digested by any technique (acid or fusion digestion). The tellurium in the resulting solution is reductively coprecipitated with added arsenite by hypophosphorous acid, and the precipitate is redissolved and analysed by catalytic anodic stripping voltammetry. Several sample digestion techniques (acid and fusion digestions) are critically assessed. The method is applied to ore certified reference materials, with tellurium concentrations spanning three orders of magnitude, and sediment certified reference materials (ocean, lake and estuarine). An overall limit of detection (LOD) of 5 ppb is achieved. Acid digestion by H2SO4 and by HClO4 or sintering with Na2O2 in glassy carbon crucibles are shown to be the most adequate sample digestion techniques.

Construction of a novel electrochemical sensor for the determination of tellurium in soil and water samples by Co nanoparticles-modified electrode

ABSTRACT The spherical Co nanoparticles (Co-NPs) were successfully fabricated through a facile one-step reduction approach. Due to the large specific surface area and excellent electronic conductivity, Co-NPs displayed excellent electrochemical performance and exhibited high sensitivity towards the detection of Tellurium (IV). The electroanalysis of Tellurium (IV) on the modified electrode was investigated by differential pulse anodic stripping voltammetry. The peak currents of Tellurium (IV) increased proportionally within the range of 0.02–1.8 and 1.8–400 mg L−1 in the 0.1 M H2SO4 solution, under the optimal conditions. The detection limit was 0.2 μg L−1 (S/N = 3). Moreover, the proposed method was successfully applied to determine Tellurium (IV) in real samples with satisfactory results. The Co-NPs/GCE not only showed good reproducibility, stability and anti-interference but also supplied a viable way for designing low toxic, environment-friendly and low-cost sensors to detect Tellurium (IV).

Selective and sensitive liquid-liquid extraction and spectrophotometric determination of tellurium(IV) using sulfur containing reagent

Abstract A simple strategy is developed for the extractive spectrophotometric determination of tellurium(IV) by using sulfur containing reagent, 4-(4'-chlorobenzylideneimino)-3-methyl-5-mercapto-1, 2, 4-triazole (CBIMMT). The [tellurium(IV)-CBIMMT] complex quantitatively extracted in dichloromethane from 3 mol L−1 of hydrobromic acid medium. The 1:2 [tellurium (IV)-CBIMMT] orange coloured complex has λmax 423 and 494 nm and stable for more than 48 h. The extracted complex have molar absorptivity 0.6686 × 104 L mol−1 cm−1 and 0.4274 × 104 L mol−1cm−1 while Sandell's sensitivity is 0.01908 µg cm−2 and 0.03115 µg cm−2 at 423 nm and 494 nm is respectively. The system adheres to Beer's law upto 20 µg mL−1 at both wavelengths; however Ringbom's plot suggests optimum concentration range is 7.0–12.5 µg mL−1 and 8.0–14.5 µg mL−1 at 423 and 494 nm respectively. The limit of detection of the method is 0.15 µg mL−1. The method has been applied for analysis of environmental and real samples.

Determination of ultratrace tellurium in water by hydride generation atomic absorption spectrometry using online separation and pre-concentration with nano-TiO2 microcolumn

Silica gel loaded with nano-TiO2 was used as solid phase extraction materials to prepare a microcolumn for the online enrichment of trace tellurium in water and then determined by hydride generation atomic absorption spectrometry (HG-AAS). The effect of pH and the flow rate of sample on the extraction efficiency, NaOH concentration on the elution efficiency and other factors influencing hydride generation efficiency of tellurium were carefully investigated. Under the optimized experimental conditions, the sensitivity and the limit of detection (LOD) of this method were 0.009 L/μg and 0.04 μg L−1, respectively, which were 1000 and 850 times better than those obtained by the traditional flame atomic absorption spectrometry (FAAS); and the LOD for tellurium was improved by 45 times in this work, when compared with that by hydride generation-atomic absorption spectrometry (HG-AAS) without any separation and pre-concentration. This method was found to be interference-free of transitional metal ions, probably because of the surface of the nano-TiO2 was positively charged under acidic conditions, and it does not adsorb their cations. This method was successfully applied to the determination of tellurium in water samples.

Total content and in vitro bioaccessibility of tellurium in Brazil nuts

Alongside the Brazil nut’s role as an excellent source of vitamins, oil, fatty acids, lipids and nutrients, it is also recognized as a rich source of selenium. The pathway along which selenium and sulfur are metabolized in plants is theorized to be the same as that used for tellurium. Total tellurium content and its bioaccessibility are then evaluated by ICP-MS. Interferences and sample preparation are evaluated for the accurate determination of tellurium, and the accuracy determined through analysis of the certified reference material 1643e. A concentration of 4.02 ± 0.391 ng g−1 is obtained as an average concentration through external and internal calibrations. Through this reliable result, tellurium bioaccessibility in Brazil nuts is obtained via an in vitro validated unified bioaccessibility method. Values of 32% and 30% of total tellurium are available in the gastric and gastrointestinal fractions, respectively.

Determination of Tellurium in Tellurium-Containing Organic Compounds by Microwave Plasma-Atomic Emission Spectrometry

A method for determining tellurium in tellurium-containing organic compounds (TOC) by a microwave plasmaatomic emission spectrometer Agilent 4100 has been suggested. One of the sample decomposition methods - the oxygen flask combustion or the acid decomposition in a heating block-can be applied. Telluradiazole derivatives and some other TOC with 20 to 58% tellurium content have been analyzed. Elements such as nitrogen, sulfur, potassium, selenium present in the TOC do not prevent from determining tellurium. The relative error of the analysis is 1-5%. Telluradiazole derivatives and some other tellurium-containing organic compounds with 20 to 58% tellurium content have been analysed by MP-AES spectrometer Agilent 4100

Study of an Opportunity of Using Solid Electrodes for Express Determination of Tellurium in Alkaline Solutions

Study of an Opportunity of Using Solid Electrodes for Express Determination of Tellurium in Alkaline Solutions

Comparison of Sample Treatment Methods for Bismuth and Tellurium Determination in Yogurt

Comparison of Sample Treatment Methods for Bismuth and Tellurium Determination in Yogurt

Direct determination of tellurium and its redox speciation at the low nanogram level in natural waters by catalytic cathodic stripping voltammetry

Tellurium is one of the elements recently identified as technologically critical and is becoming a new emergent contaminant. No reliable method exists for its determination in environmental samples such as natural waters. This gap is filled by the method described here; it allows the rapid detection of trace concentrations of Te(IV) and Te(VI) in surface waters by differential pulse cathodic stripping voltammetry. It is based on the proton reduction catalysed by the absorption of Te(IV) on the mercury electrode. Under our conditions (0.1molL−1 HCl) a detection limit of about 5ngL−1 for a deposition time of 300s is achieved. Organic matter does not represent a problem at low concentrations; higher concentrations are eliminated by adsorptive purification. Tellurium occurs primarily as Te(IV) and Te(VI) in natural waters. Thus, determining total Te requires the reduction of Te(VI) that it is not electroactive. A number of reduction procedures have been carefully evaluated and a method based on the addition of TiCl3 to the acidified samples has been proven to reduce Te(VI) at the trace level to Te(IV) reliably and quantitatively. Therefore, the procedure described allows the direct determination of total Te and its redox speciation. It is flexible, reliable and cost effective compared to any possible alternative method based on the common preconcentration-ICPMS approach. It is readily implementable as a routine method and can be deployed in the field with relative ease.

Evaluation of a new multi-walled carbon nanotube paste electrode modified with Alizarin Red S for the determination of tellurium by differential pulse stripping voltammetry

A new modified carbon paste electrode based on multi-walled carbon nanotube and Alizarin Red S acts as a chelating agent for tellurium(IV) ions, is described. The electrochemical responses were found to be analytically suitable to develop a method for the determination of tellurium at low concentration levels. Under optimised operational conditions, the sensor exhibited linear behaviour in the range of 2.0–300 ng mL−1 (correlation coefficient: 0.9982) with a detection limit of 0.45 ng mL−1. The results indicate that the sensor is sensitive and effective for the determination of tellurium in water samples and certified reference materials.

Electrodeposition as a Preconcentration and Sample Preparation Technique for Trace Selenium and Tellurium Determination by X-Ray Fluorescence Spectrometry

Electrodeposition is as an attractive technique for sample preparation in X-ray fluorescence spectrometry with advantages of low cost, high sensitivity, and minimal interferences. A simple and efficient electrolysis process for the preconcentration of selenium(IV) and tellurium(IV) is reported. The analytes were electrodeposited on a polished substrate of high purity copper, which was rinsed with deionized water, dried, and directly analyzed by x-ray fluorescence. The influence of concomitant metal ions, electrodeposition voltage, pH, and electrolyte concentration on the deposition efficiency was investigated. The presence of lead(II) was shown to improve the efficiency and reproducibility of the deposition of selenium(IV). Moreover, the results showed that the method provided superior tolerance to various coexisting ions. The reproducibility of determination was 2.4% for selenium(IV) and 1.9% for tellurium(IV) (n = 7). The detection limits for the measurement of selenium(IV) and tellurium(IV) were 0.44 and 0.57 µg L−1, respectively. The method was validated by analyzing certified reference materials and applied to the determination of trace selenium and tellurium in environmental water samples with satisfactory results.

Spectrophotometric Determination of Tellurium (IV) with Chrome Azurol S: Application to Sea Water and Synthetic Alloys

The detailed investigation of a sensitive spectrophotometric method for the determination of trace amounts of tellurium (IV) is described. The method is based on the reaction of tellurium (IV) with chrome azurol S in the presence of cetylpyridinium chloride hydrate surfactant at a final pH of 3.1 to form a pink coloured chelate absorbing maximum at 525 nm. Beer’s law is obeyed over the range (5-50) µg/25 ml, with a molar absorptivity of (2.5 ×104) l.mol-1.cm-1 and a coefficient of determination (r2) of 0.9997. Sandell’s sensitivity index is (5.104×10-3) µg.cm-2, a relative error of (0.8-0.2%) and a relative standard deviation of (0.2 to ±1.8) %, depending on the concentration levels in the calibration curve. The method has been applied successfully to determine Te (IV) in sea water and some synthetic alloys.

Rapid and sensitive determination of tellurium in soil and plant samples by sector-field inductively coupled plasma mass spectrometry

In this work, we report a rapid and highly sensitive analytical method for the determination of tellurium in soil and plant samples using sector field inductively coupled plasma mass spectrometry (SF-ICP-MS). Soil and plant samples were digested using Aqua regia. After appropriate dilution, Te in soil and plant samples was directly analyzed without any separation and preconcentration. This simple sample preparation approach avoided to a maximum extent any contamination and loss of Te prior to the analysis. The developed analytical method was validated by the analysis of soil/sediment and plant reference materials. Satisfactory detection limits of 0.17ngg−1 for soil and 0.02ngg−1 for plant samples were achieved, which meant that the developed method was applicable to studying the soil-to-plant transfer factor of Te. Our work represents for the first time that data on the soil-to-plant transfer factor of Te were obtained for Japanese samples which can be used for the estimation of internal radiation dose of radioactive tellurium due to the Fukushima Daiichi Nuclear Power Plant accident.

Studies on method development for determination of tellurium by differential pulse polarography in waste samples

Studies on method development for determination of tellurium by differential pulse polarography in waste samples

Benzenedithiol self-assembled monolayers modified gold electrodes for electrochemical determination of tellurium in the presence of selenium

Interference from selenium affects the electrochemical determination of tellurium due to their overlapped redox potentials. Benzenedithiols (BDT) self-assembled monolayers (SAMs) modified gold electrodes were investigated in this study to determine Te(IV) in the presence of Se(IV). The microenvironment from SAMs of benzenedithiols on the gold surface allows for extraction of Te(IV) selectively over Se(IV). By suppressing the reduction of Se(IV), it provides an approach to determinate Te(IV) in the presence of Se(IV) with potential applications for biological membrane, membrane techniques and geochemistry analysis.

Hydride generation induced chemiluminescence for the determination of tellurium (IV)

In the present work, hydride generation, as one of widespread application techniques in elemental analysis with the advantage of the excellent matrix separation, was attempted into the chemiluminescence. The experiment exhibited that the strong chemiluminescence emission can be obtained during the reaction between hydrogen telluride and luminol in basic medium, and a novel sensitive hydride generation-chemiluminescence (HG-CL) methodology for the determination of tellurium was proposed. Under the optimized conditions, the linear range of CL intensity versus concentration of tellurium (IV) was 10–200μgL−1, with a coefficient (R) of 0.997 and a limit of detection (S/N=3) of 2μgL−1. The results showed that the method provided superior performance with respect to tolerance to various coexisting ions such as Mg2+, Ca2+, Fe3+, Zn2+, Pb2+, As3+, Ge2+, and Hg2+. The proposed method has the advantages of simplicity, selectivity, and sensitivity, with a potential of detecting tellurium in environmental and biological samples.

Atomic absorption spectrometric determination of trace tellurium after hydride trapping on platinum-coated tungsten coil

In this work, a sensitive and simple method for the determination of tellurium was developed by hyphenation of electrically heated quartz tube atomic absorption spectrometry and tellurium hydride trapping on platinum-coated tungsten coil. With a mixture of Ar and H 2, tellurium hydride was transported to tungsten coil for trapping at 390 °C and releasing at 1200 °C. A limit of detection (LOD, 3 σ) of 0.08 ng mL − 1 was obtained with 1 min trapping (1.5 mL sampling volume), and enhancement factor was 28 compared to conventional hydride generation atomic absorption spectrometry. The LOD was better or at least comparable to literature levels involving on-line trapping and some other sophisticated instrumental method such as graphite furnace atomic absorption spectrometry (GF-AAS) and inductively coupled plasma mass spectrometry (ICP-MS), and it can be further lowered down to 0.03 ng mL − 1 by increasing the trapping time to 4 min. The platinum coating was stable for 300 firings without sensitivity loss. Interference and its alleviation were studied in detail. The proposed method was applied to the determination of tellurium in several geological standard reference materials, and the results were found in good agreement with the certified values.