Separation/Preconcentration Techniques for Rare Earth Elements Analysis

2016 ◽  
Vol 1 (10) ◽  
Author(s):  
Bin Hu ◽  
Man He ◽  
Beibei Chen ◽  
Zucheng Jiang
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Solid Phase ◽  
Phase System ◽  
Two Phase ◽  
Specific Element ◽  
System A ◽  
Subsequent Determination ◽  
The Matrix ◽  
Preconcentration Techniques

AbstractThe main aim of this chapter exactly characterizes the contribution. The analytical chemistry of the rare earth elements (REEs) very often is highly complicated and the determination of a specific element is impossible without a sample pre-concentration. Sample preparation can be carried out either by separation of the REEs from the matrix or by concentrating the REEs. The separation of REEs from each other is mainly made by chromatography.At the beginning of REE analysis, the method of precipitation/coprecipitation was applied for the treatment of REE mixtures. The method is not applicable for the separation of trace amounts of REEs. The majority of the methods used are based on the distribution of REEs in a two-phase system, a liquid–liquid or a liquid–solid system. Various techniques have been developed for the liquid–liquid extraction (LLE), in particular the liquid phase micro-extraction. The extraction is always combined with a pre-concentration of the REEs in a single drop of extractant or in a hollow fiber filled with the extractant. Further modified techniques for special applications and for difficult REE separation have been developed. Compared to the LLE, the solid phase micro-extraction is preferred. The method is robust and easy to handle, in which the solid phase loaded with the REEs can be used directly for subsequent determination methods. At present, very new solid materials, like nanotubes, are developed and tested for solid phase extraction.

RADIOIMMUNOASSAYS EMPLOYING IMMUNOSORBENTS

1969 ◽  
Vol 62 (1_Suppl) ◽  
pp. S207-S221 ◽  
Author(s):  
Leif Wide
Keyword(s):  
Liquid Phase ◽  
Cyanogen Bromide ◽  
Solid Phase ◽  
Binding Capacity ◽  
Phase System ◽  
Two Phase ◽  
System A ◽  
Technical Procedure ◽  
Particle Form ◽  
Insoluble Polymers

ABSTRACT The use of a reaction between compounds in a two phase system – a solid phase and a liquid phase – has simplified the technical procedure of the radioimmunoassays. Antigens or antibodies can be coupled covalently to insoluble polymers to form stable conjugates with retention of immunological binding capacity. Such immunosorbents can be used in radioimmunoassays in many different ways and with the solid phase in different forms. Some of these techniques seem to be universally applicable for the assay of antigens or antibodies. In one of these, antigens or antibodies are chemically coupled to cyanogen bromide activated insoluble polysaccharides in a particle form. This method which has several advantages when compared with most other radioimmunological methods is discussed in particular. Finally, a detailed description of the preparation of an immunosorbent and its use in such a radioimmunoassay system is given.

Multistep pH-Peak-Focusing Countercurrent Chromatography with a Polyethylene Glycol-Na2SO4 Aqueous Two Phase System for Separation and Enrichment of Rare Earth Elements

2012 ◽  
Vol 85 (2) ◽  
pp. 978-984 ◽  
Author(s):  
Kohei Shimizu ◽  
Hiroaki Kuribayashi ◽  
Haruna Watanabe ◽  
Tomomi Shimasaki ◽  
Kenzaburo Azuma ◽  
...  
Keyword(s):  
Rare Earth ◽  
Polyethylene Glycol ◽  
Rare Earth Elements ◽  
Phase System ◽  
Countercurrent Chromatography ◽  
Two Phase ◽  
Aqueous Two Phase System

Influence of biomass on hydrodynamics of an internal loop airlift reactor

2006 ◽  
Vol 60 (6) ◽  
Author(s):  
M. Juraščík ◽  
M. Hucík ◽  
I. Sikula ◽  
J. Annus ◽  
J. Markoš
Keyword(s):  
Aspergillus Niger ◽  
Gluconic Acid ◽  
Solid Phase ◽  
Biomass Concentration ◽  
Airlift Reactor ◽  
Phase System ◽  
Two Phase ◽  
Experimental Conditions ◽  
Internal Loop ◽  
Three Phase

AbstractThe effect of the biomass presence on the overall circulation velocity, the linear velocities both in the riser and the downcomer and the overall gas hold-up was studied in a three-phase internal loop airlift reactor (ILALR). The measured data were compared with those obtained using a two-phase system (air—water). All experiments were carried out in a 40 dm3 ILALR at six different biomass concentrations (ranging from 0 g dm−3 to 7.5 g dm−3), at a temperature of 30°C, under atmospheric pressure. Air and water were used as the gas and liquid model media, respectively. Pellets of Aspergillus niger produced during the fermentation of glucose to gluconic acid in the ILALR were considered solid phase. In addition, liquid velocities were measured during the fermentation of glucose to gluconic acid using Aspergillus niger. All measurements were performed in a bubble circulation regime. At given experimental conditions the effect of the biomass on the circulation velocities in the ILALR was negligible. However, increasing of the biomass concentration led to lower values of the total gas hold-up.

scholarly journals Geochemistry and Fuid-Inclusion Microthermometry of the Farsesh Barite Deposit, Iran

Geologos ◽  
2014 ◽  
Vol 20 (3) ◽  
pp. 201-214 ◽  
Author(s):  
Alireza Zarasvandi ◽  
Nazanin Zaheri ◽  
Houshang Pourkaseb ◽  
Abbas Chrachi ◽  
Hashem Bagheri
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Open Space ◽  
Sea Water ◽  
Shear Zones ◽  
Major And Trace Elements ◽  
Petrographic Analysis ◽  
Two Phase ◽  
Moderate Salinity ◽  
Scatter Plots

Abstract The Permian carbonate-hosted Farsesh barite deposit is located southeast of the City of Aligudarz in the province of Lorestan, Iran. Structurally, this deposit lies in the Zagros metallogenic belt and the Sanandaj-Sirjan Zone. Barite mineralisations occur as open-space flling veins, and as massive and replacement ores along fractures, faults and shear zones of the Permian carbonate host rocks. In order to determine the structure, in addition to pe-trographic and fuid-inclusions studies, an ICP-MS analysis was carried out in order to measure the major as well as the trace and rare earth elements. The Farsesh barite deposit has a simple mineralogy, of which barite is the main mineral, followed by calcite, dolomite, quartz, and opaque minerals such as Fe-oxides. Replacement of bar-ite by calcite is common and is more frequent than space-flling mineralisation. Sulphide minerals are minor and mainly consist of chalcopyrite and pyrite, which are altered by weathering to covellite, malachite and azurite. Petrographic analysis and micro-thermometry were carried out on the two-phase liquid/vapour inclusions in ellipsoidal or irregularly shaped minerals ranging in size from 5–10 µm. The measurements were conducted on fuid inclusions during the heating and subsequent homogenisation in the liquid phase. The low homogenisation temperatures (200–125°C) and low to moderate salinity (4.2–20 eq wt% NaCl) indicate that the barite had precipitated from hydrothermal basinal water with low to moderate salinity. It appears from the major and trace elements that geochemical features such as Ba and Sr enrichment in the barite samples was accompanied by depletion of Pb, Zn, Hg, Cu and Sb. The geochemistry of the rare earth elements, such as low σREE concentrations, LREE-enrichment chondrite-normalised REE patterns, the negative Ce and positive Eu anomalies, the low Ce/La ratio and the positive La and Gd anomalies, suggest that the Farsesh barite was deposited from hydrothermally infuenced sea water. The Farsesh deposit contains low-temperature hydrothermal barite. The scatter plots of the barite (close to sea water) in different areas on the CeN/SmN versus CeN/YbN diagram support the possibility that the barite was formed from seawater-bearing hydrothermal fuids.

A Rapid and Accurate X-Ray Determination of the Rare Earths Elements in Solid or Liquid Materials using the Double Dilution Method

1968 ◽  
Vol 12 ◽  
pp. 546-562
Author(s):  
R. Tertian
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Accurate Determination ◽  
Fluorescence Analysis ◽  
Dilution Method ◽  
Practical Advantage ◽  
X Ray ◽  
The Matrix

AbstractThe double dilution method has many important advantages. For any element to be determined, let us say A, It enables us to control or calculate the matrix factor (sum of the absorption end enhancement effects) for the sample being Investigated towards A radiation, and it furnishes corrected Intensities which are strictly proportional to A concentration. Thus the results are exact, whatever the general composition of the sample, their accuracy depending only on the quality of measurement and preparation. Another major practical advantage is that the method does not require systematic calibration but only a few permanent standards consisting of a pure compound or of an accurately known sample.The procedure has been tested successfully for accurate determination of rare earth elements using, for solid materials such as ores and oxide mixtures, the borax fusion technique. It also can be readily applied to liquids. All the rare earth elements can be titrated by that method, as well as yttrium, thorium and, if necessary, all the elements relevant to X-ray fluorescence analysis. The concentration range considered for solids is of one comprised between 0.5 and 100 % and, with a lesser accuracy, between 0.1 and 0-5 % Examples are given relative to the analysis of various ores. Finally it rcust be pointed out that the method is universal and applies to the analysis of every solid, especially ores, provided that they can be converted to solid or liquid solutions. It appears that most industrial analyses can be worked on In this way.

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