Method For Determination Of Cobalt Research Articles

Determination of cobalt and tungsten in human urine by inductively coupled plasma mass spectrometry

Objective: To establish a inductively coupled plasma mass spectrometry method for the determination of trace cobalt and tungsten in human urine. Methods: The authors used 1% nitric acid solution as diluent in October-December 2021, the sample dilution factor and internal standard element were optimized by single factor rotation experiment, and the difference between the working curve and the standard curve was compared. Results: The method uses working curve to determine cobalt and tungsten in urine, the linear range of this method was 0.0~10.0 μg/L, the correlation coefficient was 0.999 9, the detection limits respectively were 0.005 μg/L (cobalt) and 0.09 μg/L (tungsten), the recoveries of samples respectively were 87.0%~100.2% (cobalt) and 89.4%~104.8% (tungsten), the relative standard deviations respectively were 0.4%~4.4% (cobalt) and 0.6%~3.8% (tungsten) . Conclusion: A simple and rapid method for determination of cobalt and tungsten in urine has been established. This method has the advantages of simple operation, high sensitivity, low detection limit and good stability. It is suitable for determination of cobalt and tungsten in urine of all kinds of people.

Worldwide research on extraction and recovery of cobalt through bibliometric analysis: a review.

Cobalt is a strategic and critical mineral whose demand is expected to grow rapidly. This study aims to provide a comprehensive summary of cobalt extraction and recovery research from 2012 to 2021 in the form of bibliometric analysis. The work was based on the Science Citation Index Expanded (Web of Science) and carried out using the InCites of Clarivate for bibliometric data analysis and the software VOSviewer for science mapping. By analyzing a dataset of 4967 publications, the most influential journals, countries, authors, institutions, and publications were identified, and the keyword co-occurrence networks were mapped. The China mainland produced the most publications, while the USA had the highest average number of citations per publication and the UK was the most collaborative with other countries. The keyword analysis shows that the research hotspots gradually shifted over time from early means and methods for determination of cobalt in solution to recovery of cobalt from spent lithium batteries, smelting slag, copper-cobalt ore, etc. The research will be focused on further improvement and optimization of the separation, extraction, and recovery processes of cobalt from spent batteries in recent and future years, and three approaches were promoted to facilitate economization and industrialization of the processes in this field.

A New Simple and Fast Method for Determination of Cobalt in Vitamin B12 and Water Samples Using Dispersive Liquid-Liquid Microextraction and Digital Image Analysis

In this work, a simple and fast method for the determination of cobalt in vitamin B12 and water samples was developed. The procedure is based on the preconcentration of the element using dispersive liquid-liquid microextraction (DLLME) and subsequent detection by digital image colorimetry. DLLME was performed with trichloroethylene (extraction solvent) and ethanol (dispersive solvent). The element was extracted in the form of its complex with 2-(2-thiazolylazo)-p-cresol (TAC). The optimal working conditions were obtained through univariate optimization. The variables studied were pH, the volume of extraction solvent, and the volume of dispersive solvent. Under optimal conditions, the method presented a limit of detection of 0.9 μg L−1 and precision (relative standard deviation) of 4.0%, for 25.0 μg L−1 cobalt solutions. The procedure was applied to the determination of cobalt in vitamin B12 and water samples. The method presents a simple, fast, and low-cost procedure, presenting itself as an excellent alternative to the determination of cobalt in the samples analyzed.

Determination of Cobalt in the Form of an Ion Associate in Vitamin B12

The possibility of application of the ion-associated complex formed between the anionic chelate cobalt(II)-4-(2-thiazolylazo) resorcinol (TAR) with the cation of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) for extraction-spectrophotometric determination of cobalt in the form of an ion associate in Vitamin B12 was studied. The liquid–liquid extraction system Co(II)-TAR-MTT-H2O-CHCl3 was applied. This system was chosen by our previous research of the ion associates of the cobalt by spectrophotometric investigation of fourteen different liquid–liquid extraction systems, containing azo derivatives of resorcinol (TAR or 4-(2-pyridylazo) resorcinol (PAR)) and mono or ditetrazolium salts. Based on the obtained results, a sensitive, relatively simple, convenient and inexpensive method for determination of cobalt in the form of an ion associate in Vitamin B12 was developed. The proposed method can be implemented for biological, medical and pharmaceutical samples containing cobalamin (Vitamin B12).

Determination of tungsten and cobalt in the air of workplace by ICP-OES

Objective: To establish the inductively coupled plasma optical emission spectrometry (ICP-OES) method for determination of cobalt and tungsten in the air of workplace. Methods: The cobalt and tungsten were collected by filter membrane and then digested by nitric acid, inductively coupled plasma optical emission spectrometry (ICP-OES) was used for the detection of cobalt and tungsten. Results: The linearity of tungsten was good at the range of 0.01-1 000 μg/ml with a correlation coefficient of 0.999 9, the LOD and LOQ were 0.006 7 μg/ml and 0.022 μg/ml, respectively. The recovery was ranged from 98%-101%, the RSD of intra-and inter-batch precision were 1.1%-3.0% and 2.1%-3.8%, respectively. The linearity of cobalt was good at the range of 0.01-100 μg/ml with a correlation coefficient of 0.999 9, the LOD and LOQ were 0.001 2 μg/ml and 0.044 μg/ml, respectively. The recovery was ranged from 95%-97%, the RSD of intra-and inter-batch precision were 1.1%-2.4% and 1.1%-2.9%, respectively. The sampling efficiency of tungsten and cobalt were higher than 94%. Conclusion: The linear range, sensitivity and precision of the method was suitable for the detection of tungsten and cobalt in the air of workplace.

Determination of Trace Cobalt in Water by Reversed Flow Injection Spectrophotometry

A method for determination of cobalt in water by flow injection spectrophotometry based on the catalytic effects of cobalt on the oxidation reaction of arsenazo III by potassium bichromate in HAc-NaAc buffer solution of pH 4.6 was established. The relationship of the reduced absorbency to the concentration of cobalt was good linearity and the maximum absorption peak located at 550 nm. The affecting factors on the strength of absorption including acidity, dosage, temperature, coexisting ions and so on, and the optimal conditions of the reaction in the system were investigated. Calibration graphs were linear for ranges of 0 to 20 μg/mL and a detection limit of 0.3 μg/mL cobalt was achieved. The proposed method was successfully applied to the analyses of industrial waste water samples, with relative standard deviation of less than 1.5% and the recoveries are 95.1% to 96.8%for the determination of cobalt.

A green preconcentration method for determination of cobalt and lead in fresh surface and waste water samples prior to flame atomic absorption spectrometry.

Cloud point extraction (CPE) has been used for the preconcentration and simultaneous determination of cobalt (Co) and lead (Pb) in fresh and wastewater samples. The extraction of analytes from aqueous samples was performed in the presence of 8-hydroxyquinoline (oxine) as a chelating agent and Triton X-114 as a nonionic surfactant. Experiments were conducted to assess the effect of different chemical variables such as pH, amounts of reagents (oxine and Triton X-114), temperature, incubation time, and sample volume. After phase separation, based on the cloud point, the surfactant-rich phase was diluted with acidic ethanol prior to its analysis by the flame atomic absorption spectrometry (FAAS). The enhancement factors 70 and 50 with detection limits of 0.26 μg L−1 and 0.44 μg L−1 were obtained for Co and Pb, respectively. In order to validate the developed method, a certified reference material (SRM 1643e) was analyzed and the determined values obtained were in a good agreement with the certified values. The proposed method was applied successfully to the determination of Co and Pb in a fresh surface and waste water sample.

Solid-Phase Extraction and Atomic Absorption Spectrometric Determination of Cobalt Using an Octadecyl Bonded Silica Membrane Disk Modified with Cyanex 272

A simple SPE method for determination of cobalt(II) using a C18 bonded silica membrane disk impregnated with Cyanex 272 has been developed. Cobalt(II) was quantitatively sorbed at pH 6.0 from a sample solution and eluted using 10.0 mL 1.0 M HNO3 prior to its flame atomic absorption spectrometric determination. The influence of eluting agents, the minimum volume and maximum flow rate of the eluent, and interfering ions on cobalt(II) was studied. The method developed for cobalt(II) had an LOD of 1.4 microg/L, and a preconcentration factor > 200 with an RSD of 0.6%. The reusability of the modified disk was for 40 cycles. The method was applied for the determination of cobalt in certified samples, urine, and industrial sludge samples.

H-point standard addition method for simultaneous determination of cobalt(II) and zinc(II) ions

H-point standard addition method for simultaneous determination of cobalt(II) and zinc(II) ions

Synthesis and characterisation of 2-hydroxy-3-methoxy benzaldehyde thiosemicarbazone (HMBATSC) and its application of simultaneous second order derivative spectrophotometric method for determination of cobalt(II), nickel(II) and vanadium(V)

2-hydroxy-3-methoxy benzaldehyde thiosemicarbazone (HMBATSC) has been synthesized, characterized and employed as a simple simultaneous second order derivative spectrophotometric method for the analysis of a three-component system containing cobalt(II) nickel(II) and vanadium(V) without separation. The reagent (HMBATSC) reacts with cobalt(II), nickel(II) and vanadium(V) at pH 6.0, forming soluble brown, yellow and green coloured species, respectively. Cobalt, nickel and vanadium present in the mixture are simultaneously determined without solving the simultaneous equations by measuring the second derivative amplitudes at 460 nm, 450 nm and 430 nm, respectively. Further, the derivative amplitudes obey Beer's law at 460 nm, 450 nm and 430 nm for Co(II), Ni(II) and V(V) in the range 0.059 – 3.535 μg ml−1, 0.058 – 3.425 μg ml−1 and 0.051 – 4.074 μg ml−1, respectively. A large number of additional ions did not interfere with the method. The simultaneous method can be applied for the determination of cobalt(II) ...

Metrological assessment of the high-accuracy RNAA method for determination of cobalt in biological materials.

The paper summarizes work on the development of the high-accuracy RNAA method for the determination of trace amounts of cobalt in biological materials. The method is based on a combination of neutron activation with selective and quantitative isolation of the analyte in a state of high radiochemical purity by use of column chromatography followed by gamma-ray spectrometric measurements. The method was devised according to a set of rules, which were formulated to obtain high accuracy of the method. The procedure has been also equipped with several criteria as key factors in quality assurance. Qualification of the high-accuracy RNAA method as a primary ratio method has been demonstrated and its usefulness in the certification of the candidate reference materials tea leaves and mixed Polish herbs is presented.

Dosage du cobalt par spectrométrie d'absorption atomique et application à l'analyse de la vitamine B12

We purpose in this study to describe a method for determination of vitamin B12 based in the speciation of the metal element: cobalt. First, a method for determination of cobalt by atomic absorption spectrometry with graphite furnace atomization was evaluated. Calibration was prepared with aqueous solution is linear from 10 to 150 μg/L (correlation coefficient = 0,98); the limit of detection is about 6,8 μg/L. The precision (repeatability: 1,2 à 6,9 %) and accuracy (108 %) were acceptable. This procedure was studied in serum with the same protocol. Secondly, the method was applicated to the determination of vitamin B12 in pharmaceutical injection and in serum. Recoveries ranged from 98,5 to 100,9 % for drugs. Comparison with results obtained with the microparticule enzymatic method (MEIA Abbott®) for serums were less satisfactory.

Review of Spectrophotometric Methods for Determination of Cobalt(II)

Review of Spectrophotometric Methods for Determination of Cobalt(II)

Mechanised flow system for on-line microwave digestion of food samples with off-line catalytic spectrophotometric determination of cobalt at ng l-1 levels.

A mechanised system for on-line slurry food sample digestion was developed and an off-line cobalt determination was performed. The stabilised slurry sample was introduced into an air carrier stream until reaching the digestion coils located inside a household microwave oven. Software written in Visual Basic 3.0 was developed to permit the transport of the slurry samples and the programming of the microwave oven and also the control of the mineralization valve. The proposed system was optimized for determination of cobalt in certified samples such as mussels, bovine liver and fish and also uncertified fish samples. The digestion parameters were established as 3 mol l-1 HNO3 for mussels, 3 mol l-1 HNO3 plus 0.16% v/v H2O2 for bovine liver and 12 mol l-1 HNO3 for fish employing maximum power for 5 min of microwave actuation. In the subsequent spectrophotometric method for the catalytic determination of cobalt, the Tiron and hydrogen peroxide concentrations were 1.8 x 10(-3) and 3.0 x 10(-4) mol l-1, respectively, and the sample residence time was 300 s as determined by an optimisation process. The proposed method features a linear range from 10 to 200 ng l-1 Co (r > 0.996) with detection and quantification limits of 1.7 and 5.5 ng l-1 Co, respectively. The precision, expressed as RSD, was 2.4% (n = 12) for repeatability and 5.2% (n = 10) for reproducibility and the accuracy of the proposed method was assessed by using certified samples and an alternative technique (ETAAS).

A Colorimetric Method for Trace Level Determination of Cobalt in Natural and Waste Water Samples

A colorimetric method which can be used to determine concentrations of cobalt as low as 0.1 mg/L in natural and waste water samples is developed. This method involves the complexation of cobalt with 1-nitroso-2-naphthol-3,6, disulfonic acid disodium salt at the pH of 6.0, and the measurement of the absorbance of the colored complex at 520 nm. The interference by other metals as well as common anions was also investigated. Under the conditions employed, cobalt determination was found to be free of any interference by various metal ions and anions. The effect of digestion process using the E.P.A procedure 3030E was also investigated. On synthetic samples, the results on the determination of cobalt in digested and undigested samples were same within experimental error showing the digestion procedures did not hinder the applicability of the method to environmental samples. The method was then applied to actual waste water samples to determine the concentration of cobalt. Greater than 98% recovery of cobalt was obtained using the method developed, and better than 96% agreement between the concentrations of cobalt determined using this method and the atomic absorption spectroscopy was obtained. The method is applicable for the detection of cobalt at concentrations in environmental samples as low as 0.1 mg/L with greater than 95% accuracy, and is proposed to be used as a standard method for a rapid on-site analysis of cobalt in water and waste water samples.

Simultaneous determination of cobalt, nickel and iron by multi-wavelength spectrophotometry

A method for the simultaneous spectrophotometric determination of cobalt, nickel and iron based on the formation of their complexes with 1,5-bis(di-2-pyridylmethylene) thiocarbonohydrazide is proposed. The absorption curves of these complexes overlap severely in the scanning range 390–510 nm. The analyte concentrations are calculated by a least squares fit of the pure spectra to the mixture spectra, which therefore makes the simultaneous determination of these metallic ions possible without tedious pretreatment. The detection limits afforded by the proposed method range from 0.05 μg/ml for Fe and Ni to 0.1 μg/ml for Co. Root-mean-squared errors of prediction of 0.085 μg/ml for Co, 0.048 μg/ml for Ni and 0.1172 μg/ml for Fe were obtained using the wavelength range 400–510 nm and 0.147 μg/ml for Co, 0.107 μg/ml for Ni and 0.127 μg/ml for Fe using the wavelength range 420–434 nm. The effect of interferences is studied and the proposed method is applied to analysis for the above elements in synthetic samples and real samples, such as biological materials and alloys.

Determination of Ni and Co using 2-quinolinethiol by adsorptive voltammetry

A new method for the simultaneous determination of cobalt and nickel has been developed by differential pulse adsorptive voltammetry using 2-quinolinethiol as chelate. A separation of the two peaks by 0.3 V was achieved, allowing the determination of the two metals in a wide range of concentrations. The influence of pH, nature of the supporting electrolytes, preconcentration time and applied potential was investigated. Pb, Cd, Fe, Zn and Cr do not interfere. The determination limits were 10−8 mol/l for Co and 10−9 mol/l for Ni. The method was applied to mussel tissues and wines.

The influence of ultra-violet irradiation on the determination of nickel and cobalt in natural waters by adsorption voltammetry

Recently, the highly specific and sensitive technique of adsorption voltammetry has been developed for ultra-trace metal determination. the method involves adsorption of a ligand at an electrode, accumulation of the metal as an adsorbed complex and reduction of the adsorbed metal complex. In this work, the differential pulse adsorption voltammetric method for the determination of cobalt and nickel has been examined to determine whether adsorption voltammetric methods are likely to provide equivalent data to the widely used methods based on anodic stripping voltammetry when applied to speciation studies in natural water systems. Importantly, in contrast to anodic stripping methods for the determination of copper, lead and cadmium in natural waters, data for cobalt and nickel are essentially independent of the presence or absence of ultra-violet irradiation pretreatment methods aimed at removing dissolved organic material. It is therefore suggested that dimethylgloxime, the organic reagent used in the adsorption voltammetric method for determination of cobalt and nickel, enables the detection not only of labile nickel and cobalt complexes of the kind determined in anodic stripping voltammetry but also of the majority of organically bound cobalt and nickel complexes. That is, the high stability constants and specificity of dimethylglyoxime towards cobalt and nickel enables essentially total metal concentrations to be determined. From this result, it is suggested that all speciation studies on natural water systems undertaken via adsorption voltammetric methods will need to be assessed critically to establish whether total metal or specific forms of the metal are being determined. That is, because anodic stripping and adsorption voltammetric methods are based on fundamentally different principles they need not necessarily provide equivalent data in the area of trace metal analysis.

Spectrophotometric determination of cobalt with ethylenediaminetetraacetic acid and tert-butyl hydroperoxide

A method for the spectrophotometric determination of cobalt with EDTA and tert-butyl hydroperoxide is proposed. The spectrum shows an absorption maximum at 580 nm in basic medium. The effects of amount of reagent, acidity, time and temperature have also been studied. Beer's law is obeyed over the range 50–170 µg ml–1 of cobalt with a minimum photometric error of 2.91%. The reproducibility, precision and potential interferents have been investigated.

Spectrophotometric determination of cobalt with cyclohexane-1, 2-dione bis(2-pyridylhydrazone)

A method for the spectrophotometric determination of cobalt with cyclohexane-1,2-dione bis(2-pyridylhydrazone) is described. The pink complex is formed at an initial pH of 4–5 in a medium containing 12%V/V dimethylformamide, and the absorbance is measured at 525 nm at a final perchloric acid concentration of ca. 0.5 M. The molar absorbtivity is 13700 l mol–1 cm–1. The method has been applied to the determination of cobalt in alloys and minerals.