Determination Of Neodymium Research Articles

Determination of Nd isotopic composition in seawater using newly developed solid phase extraction and MC-ICP-MS

Determination of neodymium (Nd) isotopic composition in seawater is useful for tracing water masses and geochemical cycles for lithogenic elements in the ocean. A new separation procedure for determination of the Nd isotopic composition of in seawater samples was developed that offers enhanced sample throughput and improved measurement reliability. The procedure consists of conventional Fe hydroxide coprecipitation, solid phase extraction using DGA chelating resin column chromatography, and Ln Resin column chromatography to preconcentrate samples. High selectivity in HNO3 medium and elution by low concentration HCl medium for Nd are characteristics of extraction using DGA Resin®, and they allowed an evaporation step to be omitted between the chromatographic steps. These chromatographic steps, using DGA Resin to separate REEs and Ln Resin® to remove Sm, were refined from a previous study. The procedural blank value of Nd was obtained as 2 pg (n = 6) from 3 L of water samples. Chemical yield of Nd from 3 L of seawater ranged within 90–95%. The developed procedure was combined with multiple collector-ICP-MS and applied to analysis of vertical seawater samples obtained from the western subarctic gyre of the North Pacific Ocean, where εNd ranged from −1.29 ± 0.42 at the surface to −3.80 ± 0.41 at 4000 m depth. These results were validated by comparing them with results obtained by the conventional method verified in the GEOTRACES inter-calibration program.

Comparative Studies of Neodymium (III) Selective Poly(vinyl chloride) Electrodes Based on O, N, S Donor Ionophores

Two Schiff-base chelates 4-Methoxy-2-{((2-(pyridin-2-yl)ethyl)sulfanyl}ethyl) iminomethyl phenol (L1), and 2,2'-{sulfanediylbis (ethane-2,1-diyinitro methylylidene)}-diphenol (L2) have been synthesized and used as neutral carrier for the fabrication of Nd(III) selective membrane electrode. The values of formation constant indicates that the proposed ionophore forms stable complex with Nd(III). The addition of sodiumtetraphenylborate and various plasticizers, viz., o-NPOE TBP DBBP TEP and DOS has been found to substantially improve the performance of the electrode. The best performance was obtained with the electrode no.6 having membrane of ionophore (L2) with composition PVC: o-NPOE: ionophore (L2): NaTPB (%, w/w) of 32: 61:5:2. This electrode exhibits Nernstian response with slope 21.1 ± 0.3 mV decade -1 of activity in concentration range 1.6 x 10 -8 to 1.0 x 10 -1 M Nd(III), performs satisfactorily over wide pH range ( 2.5 - 8.3.), with a fast response time (8s). The elec- trode was also found to work satisfactorily in partially non-aqueous media up to 20% content of methanol, ethanol or acetone and could be used for a period of 5 weeks without any change in response characteristics. The Nd(III) selective electrode was used as an indicator electrode for the titration of 50 ml 1 x 10 -3 M EDTA solution. The selectivity coefficients determined by using fixed interference method (FIM) indicate high selectivity for neodymium. The application of prepared electrode has been demon- strated in the determination of neodymium (III) in monazite, bastnasite and spiked water sample.

Determination of Neodymium(III) in Aqueous and Soil Samples with Use of a High-Sensitive and Selective Membrane Sensor

Determination of Neodymium(III) in Aqueous and Soil Samples with Use of a High-Sensitive and Selective Membrane Sensor

Potentiometric determination of neodymium (III) ions using tin (IV) antimonotungstate and zirconium (IV) antimonotungstate as electro-active materials

Neodymium (III)-selective electrodes have been prepared by using tin (IV) antimonotungstate (SnSbW) and zirconium (IV) antimonotungstate (ZrSbW) as electro-active materials and epoxy resin as a binding material. In the case of SnSbW, best performance is exhibited by a membrane having the composition: tin (IV) antimonotungstate (50%) and epoxy resin (50%). It shows excellent response in the concentration range of 10–4 M to 10–1 M Nd (III) ion with a super-Nernstian slope of 40.0 mV/decade. It has a fast response time of 20 seconds and can be used for at least six months without any considerable divergence in potential. In the case of ZrSbW, best performance is exhibited by a membrane having the composition: zirconium (IV) antimonotungstate (40%) and epoxy resin (60%). It shows excellent response in the concentration range of 10–5 M to 10–1 M Nd (III) ion with a near-Nernstian slope of 25.0 mV/decade. It has a fast response time of 10 seconds and can be used for at least six months without any considerable divergence in potential. Effect of internal solution has been studied and the electrode was successfully used in partially non-aqueous medium, too. Selectivity coefficients have been determined by FIM method, with respect to alkali, alkaline earth, some transition and rare earth metal ions. ZrSbW electrode can be used in the pH range of 2.9–9.9 and SnSbW shows pH range 3.0–9.0. Both the electrodes have been used as indicator electrodes in the potentiometric titration of Nd (III) ions against EDTA.

Comparative studies of neodymium (III)-selective PVC membrane sensors

Sensors based on two neutral ionophores, N,N′-bis((1H-pyrrol-2-yl)methylene)cyclohexane-1,2-diamine ( L 1 ) and 3,3′-(cyclohexane-1,2-diylbis(azan-1-yl-1-ylidene)bis(methan-1-yl-1-ylidene)bis(5-hydroxymethyl)pyridine-2-ol) ( L 2 ) are described for quantification of neodymium (III). Effect of various plasticizers; 2-nitrophenyloctylether ( o-NPOE), dibutyl butylphosphonate (DBBP), tri-n-butyl phosphates (TBP), dioctylpthalate (DOP) and chloronapthalen (CN) and anion excluder, sodiumtetraphenylborate (NaTPB) has been studied. The membrane composition of PVC: o-NPOE:ionophore ( L 1 ):NaTPB (w/w; mg) of 150:300:5:5 exhibited best performance. The sensor with ionophore ( L 1 ) exhibits significantly enhanced selectivity towards neodymium (III) in the concentration range 5.0 × 10 −7 to 1.0 × 10 −2 M with a detection limit of 1.0 × 10 −7 M and a Nernstian compliance (19.8 ± 0.3 mV decade −1 of activity) within pH range 4.0–8.0. The response time of sensor was found as 10 s. The influence of the membrane composition and possible interfering ions has also been investigated on the response properties of the electrode. The fast and stable response, good reproducibility and long-term stability of the sensor are observed. The sensor has been found to work satisfactorily in partially non-aqueous media up to 20% (v/v) content of methanol, ethanol or acetonitrile and could be used for a period of 3 months. The selectivity coefficients determined by using fixed interference method (FIM) indicate high selectivity for neodymium. The proposed electrode shows fairly good discrimination of neodymium (III) from other cations. The application of prepared sensor has been demonstrated in the determination of neodymium (III) in spiked water samples.

Determination of Neodymium and Ytterbium by Isotope Dilution Laser Mass Spectrometry

The experimental conditions for minimizing errors in the laser mass spectrometric (LMS) analysis of isotopic ratios for Nd and Yb were found, and the optimum isotope pairs for determining these elements with the use of isotope dilution (ID) were chosen. The precision and accuracy of LMS data, which are characterized by relative random errors (RSD) and relative systematic errors (δ), can be improved using ID. The values for Nd or Yb were no higher than RSD = 2.9% and δ = 0.024 or RSD = 5% and δ = 0.097, respectively.

Determination of neodymium, holmium and erbium in mixed rare earths by norfloxacin

Norfloxacin (NFX) is proposed as reagent for the derivative spectrophotometric determination of neodymium, holmium and erbium in mixed rare earths. The absorption spectra of 4f electron transitions of the systems of neodymium, holmium and erbium complexes with norfloxacin in presence of cetylpyridinium chloride were studied by normal and derivative spectra. The absorption bands found normally at 575 nm for neodymium, 450 nm for holmium and 523 nm for erbium were enhanced markedly. Using the second derivative spectrum, Beer’s Law is obeyed from 5.0 × 10–5∼ 2.5 × 10–4 mol dm–3 for neodymium, holmium and erbium. The relative standard deviations are 1.0, 1.4 and 1.1% for 6.9 × 10–5 mol dm–3 of neodymium, 6.1 × 10–5 mol dm–3 of holmium and 6.0 × 10–5 mol dm–3 of erbium, respectively. A method for the direct determination of neodymium, holmium and erbium in mixtures of rare earth elements with good accuracy and selectivity, is described.

Study of the absorption spectra of 4f electron transitions of the neodymium and erbium complexes with diphacinone and Triton X-100 and its analytical application

Abstract The absorption spectra of 4 f electron transitions of the neodymium and erbium complexes with 2-(diphenylacetyl)indan-1,3-dione and octylphenol poly(ethyleneglycol)ether have been studied by normal and derivative spectrophotometry. Use of third-derivative spectra can eliminate the interference from other rare earth elements and enhance the sensitivity for neodymium and erbium. Beer's law is obeyed for 0–35 μg cm −3 of neodymium and 0–50 μg cm −3 of erbium. Their molar absorptivity at the maximum absorption bands are about 7.4 times for neodymium and 11.4 times for erbium greater than that for the equivalent amount of neodymium and erbium in the chlorides. The relative standard deviations evaluated from seven independent determinations of 8.3 μg cm −3 of neodymium and 8.5 μg cm −3 of erbium are 1.4 and 1.5%, respectively. The detection limits (signal to noise ratio = 2) are 0.06 μg cm −3 for neodymium and 0.1 μg cm −3 for erbium. A method for the direct determination of neodymium and erbium in mixtures of rare earth elements with good accuracy and selectivity, is described.

Kinetic-spectrophotometric method for the determination of neodymium and mixtures of neodymium with lanthanum and cerium

A kinetic method is described for the determination of neodymium, based on its inhibitory effect on the acetonitrile-catalysed oxidation of Pyrocatechol Violet by hydrogen peroxide. The reaction rate was followed spectrophotometrically at 490 nm. The method allows the determination of neodymium in the concentration range 0.14–1.4 µg ml–1 with a relative standard deviation of about 4%. The effect of lanthanum and cerium on the reaction inhibited by neodymium, which is manifested by an increase in this effect, was used for their determination in mixtures with neodymium. Binary and ternary mixtures of neodymium, lanthanum and cerium were analysed with a relative standard deviation of up to 6.1%.

Micellar systems in flow injection for the spectrophotometric determination of neodymium in glasses

Neodymium (0.03–21 µg ml–1) can be determined at a sampling rate of 120 h–1 by injection at pH 2.7 in the presence of 0.4 M NaNO3 into a carrier containing 1.6 × 10–3M 1-(2-pyridylazo)-2-naphthol (PAN)(0.15 g of Triton X-100 plus 1 mg of PAN) buffered at pH 9.2 [HBO2+ NaBO2(0.04 M)] and monitoring the absorbance at 560 nm. The influence of the presence of electrolytes in the matrix on peak height was studied. The interferences produced by heavy metals were eliminated by extracting their diethyldithiocarbamates into chloroform-ethyl actate (1 + 1). The method was applied to the determination of Nd in a commercial glass.

Determination of neodymium with 1-(2-pyridylazo)-2-naphthol by high-order derivative spectrophotometry. Application to the determination of neodymium in glasses

A method is described for the spectrophotometric determination of neodymium by measuring the peak to valley signal of the fourth-derivative of the absorption of the Nd-PAN-Triton X-100 system. The chemical and instrumental variables (wavelength range, Δλ and order of the derivative) were optimised by the modified simplex method. Under the optimum experimental conditions the calibration line fits the equation d4A/dλ4= 2.48 × 105[Nd]– 0.002 (r= 0.9998) and has a detection limit of 11 p.p.b. The method was applied to the determination of neodymium in glasses.

Determination of neodymium with 1-(2-Pyridylazo)-2-naphthol in micelles of Triton X-100 by derivative spectrophotometry

Determination of neodymium with 1-(2-Pyridylazo)-2-naphthol in micelles of Triton X-100 by derivative spectrophotometry

Determination of Neodymium in Bastonaesite Concentrates by Photoacoustic Spectrometry

The Nd contents of bastonaesite concentrates were determined by photoacoustic spectrometry without dissolution or separation. The bastonaesite concentrates were suitably modeled with a Nd carbonate-La carbonate system. To deal with the light scattering samples, a Kubelka-Munku type calibration method was modified, and the linear relationship between Nd content and the response function was obtained up to 20%(wt/wt) of Nd. The effect of particle size was relatively small under 325 mesh. The effect of impurities on the fluorecence process was also discussed.

Determination of neodymium by ion-exchanger absorptiometry with the f-f electron transition band

Ion-exchanger absorptiometry, based on the direct measurement of light absorption by neodymium in the cation-exchange phase, has been developed for metal determination. In the presence of ethylenediaminetetraacetic acid (EDTA) about 99% of the neodymium in a 200-ml sample solution (pH 2.2 to 2.5) was concentrated in 0.50 g Muromac 50W-X12 cation exchanger within 15 min. EDTA does not interfere with the sorption of neodymium ions on the resin but suppresses spectrophotometric interference by ferric ions and ion-exchange saturation by ferric and thorium cations. The resin-phase attenuations at 740.5 nm and of the resin background at 620 nm were used for measurements with a 5-mm cell. Neodymium in the range 0.1 – 10 mg could be simply and rapidly determined without interference from other rare earths and the proposed method was used to analyse the rare-earth minerals and alloys.

Determination of neodymium and boron in iron-neodymium-boron alloys by direct-current plasma atomic-emission spectrometry

Rapid, accurate methods for the determination of neodymium and boron in iron-neodymium-boron alloys are presented. The procedure involves dissolution of the alloy with nitric acid and measurement of the elemental concentrations by direct-current plasma atomic-emission spectrometry. Lithium is added in the determination of neodymium, to control interferences. The relative standard deviations are approximately 1%, and the accuracies comparable to those obtained by classical chemical methods.

Determination of neodymium, europium, gadolinium and erbium by flame emission and atomic absorption spectrometry

BS>The behavior of neodymium, europium, gadolinium and erbium in flame emission and atomic absorption spectrometry was studied in a nitrous oxide -- acetylene flame. The effects of kind of different inorganic acids (hydrochloric, nitric, perchloric, sulfuric and phosphoric acids) in the concentration range of 0.1 to 3M on the intensities of the emission and absorption at 400 ppM Nd, 50 ppM Eu, 500 ppM Gd, and 50 ppM Er were investigated. The effects of addition of metal ions such as Na, K, Mg, Ca, Sr, Ba, Mn, Fe, Cu, Zn and Al and some rare earths in the range of 100 to 10000 ppM on the intensities of the emission and absorption of Nd, Eu, Gd and Er were investigated. The intensities increased with an increase in the concentration of the metal ions (except Al) and the rare earths. The intensities appreciably decreased in the presence of 3000 to 10000 ppM Al. The calibration curves for Nd (0 to 1000 ppM), Eu (0 to 100 ppM) or Gd 10 to 10000 ppM) were not linear with both methods and exhibited a concave form with a bending away from the concentration axis. The curve for Er (0 to 100 ppM) wasmore » linear up to 50 ppM with flame emission (FE) and 60 ppM with atomic absorption (AA). Those for Nd, Eu, Gd, and Er obtsined by adding each of 2000 ppM of K, Y, and La were linear in the concentration up to 600 ppM with Fe and 1000 ppM with AA, 40 ppM with FE and 60 ppM wth AA, 600 ppM with FE and AA, and 50 ppM with FE and 60 ppM with AA, respectively. These methods were applied to synthetic samples and practical samples and good results were obtained. (auth)« less

Spectrophotometric study and analytical application of rare earth tiron complexes—I: Determination of neodymium, holmium and erbium

The absorption spectra of neodymium, holmium and erbium Tiron complexes in aqueous solution have been measured from 340 to 650 nm. The absorbance at the wavelength of maximum absorption band of an aqueous medium containing neodymium (pH 4.5), neodymium (pH 12.0), holmium (pH 5.0) and erbium (pH 5.0) Tiron complexes was about 4 (at 578 nm), 9 (at 571 nm), 9 (at 450 nm) and 5 (at 376 nm) times greater, respectively, than for the same quantities of the corresponding chlorides. The spectrophotometric determination of these elements has been investigated. Combining ratios of Tiron to rare earth have been found to be 3:2 and 2:1.