Spectrophotometric Determination Of Scandium Research Articles

Extraction of Scandium Nitrate and Thiocyanate Complexes Using Two-Phase Aqueous Systems and the Determination of Scandium

Two-phase aqueous systems, polyethylene glycol PEG-3000 (C3H7OH)–NaNO3 (NaNO3 + KSCN)–H2O, are proposed for the selective extraction of scandium nitrate and thiocyanate complexes followed by the complexometric and spectrophotometric determination of scandium. Conditions for analyte separation from rare-earth and concomitant elements are optimized. The procedures are tested on samples of rare-earth metals, concentrates, and an aluminum alloy. The relative standard deviation is not more than 0.8% for complexometric determination and 4.6% for spectrophotometric determination. The time of analysis is not longer than 30 min.

Polyelectrolyte effect on spectrophotometric determination and interaction of scandium (III) with eriochromcyanine

The influence of cationic water-soluble polyelectrolyte PSPMG on the interaction of scandium (III) with organic reagent eriochromcyanine is studied. Because the study of the possibility of obtaining new, more effective, modified reagents with a complex of better analytical characteristics is an actual analytical task. The optimal conditions of complex formation were experimentally determined: the pH range (5.5–6.5), the order of the adding of the components (1 – scandium, 2 – ECR, 3 – PSPMG, 4 – buffer solutions), the composition of the Sc-ECR-PSPMG complex (1:4:1) were experimentally determined and the molar absorption coefficient – 1.8·10 5 was calculated. A sensitive spectrophotometric method for scandium determination in solutions at the level of 10 -7 mol/L was developed. The optimal scandium sorption parameters in the form of three-component systems Sc-OR-modifier on solid-state carriers were established, scandium sorption isotherms were constructed, sorption parameters of A gran and K ads were calculated. The test systems for the identification of scandium as ternary compounds in polyurethane foam and cotton were proposed, calibration curves in the concentration range from 1·10 -6 –1·10 -5 mol/L were built and the colorimetric method of identification of scandium in solutions that accelerate analysis was proposed. It is shown that the PSPMG application is a promising direction for improvement of chemical-analytical characteristics of organic reagents (eriochromcyanine and chromazurol S) because its usage increases the sensitivity and selectivity of the spectrophotometric determination of scandium in the form of a complex Sc-OR-PSPMG.

Spectrophotometric Determination of Scandium (III) with Eriochrome Cyanine R and Cetylpyridinium Chloride – Application to Waters and Synthetic Alloys*

The detailed investigation of a sensitive and selective spectrophotometric method for the trace amounts of scandium is described. The method is based on the reaction of scandium with eriochrome cyanine R reagent in the presence of cetylpyridinium chloride surfactant at pH 4.1, to form a violet-blue ternary chelate which exhibits maximum absorption at 595nm. Beer’s law is obeyed over the range 0.1-3.0 µg25ml, i.e., 0.004-0.12 ppm, with a molar absorptivity of 1.3×105 l.mol-1.cm-1, (r=0.9991), Sandell’s sensitivity index of 0.45 ng.cm-2, a relative error of 0.0-0.4% and a relative standard deviation of ±0.6 to ±6.1 %, depending on the concentration level. The method has been applied successfully to determine, scandium in various samples of water and synthetic alloy.

Spectrophotometric Determination of Scandium(III) with o-Hydroxyhydroquinonephthalein in Cationic Micellar Media

Abstract A spectrophotometric method for determining trace amounts of scandium(III) has been established which makes use of formation of its ternary complex with o-hydroxyhydroquinonephthalein (Qnph) and N-hexadecyl-pyridinium chloride (HPC) as a cationic surfactant at pH 5.4. The molar ratio of the ternary complex among Qnph, scandium(III), and HPC is 3:2:6 in a weakly acidic medium, and its maximum absorbance is at 555 nm against a reagent blank. Beer’s law holds in the concentration range 0–4.5 μg of scandium(III) in a final volume of 10 cm3 at 555 nm. The apparent molar absorptivity is 1.0×105 dm3 mol−1 cm−1 with a Sandell sensitivity of 0.0005 μg cm−2. The coefficient of variation was 0.6% (n=5) for 2.7 μg of scandium(III).

Chlorophosphonazo-p-Cl, a new reagent for the spectrophotometric determination of scandium

Chlorophosphonazo-p-Cl, A New Reagent for the Spectrophotometric Determination of Scandium The synthesis of chlorophosphonazo-p-Cl (CPApC) and a highly sensitive method with CPApC as a new reagent for the spectrophotometric determination of scandium are described. Scandium reacts with CPApC in nitric acid medium at pH ∼2 to form a 1∶1β-type complex which has a maximum absorption at 762 nm. Under the experimental conditions employed, the apparent molar absorptivity is 1.54×105 l·mol−1·cm−1 and the relative standard deviation for 2.0μg of scandium is 0.92%. The determination range is 0–6μg of scandium in 25 ml of solution by using standard addition-deduction method. Scandium can be determined in the presence of reasonable amounts of rare earths.

Spectrophotometric Investigation and Determination of Scandium Using Semi-Xylenol Orange

Abstract The composition, stability constant and molar absorption coefficient of the chelate of scandium ion with Semi-Xylenol Orange (SXO) are determined speotrophotometrically in a medium of chloroacetate buffer. In the scandium-Semi-Xylenol Orange system, Sc(SXO) chelate is formed with a logarithmic stability constant of 19.66 and molar absorptivity of 2.4x104 (530 nm) 1 mole−1cm−1. The precision and accuracy attainable in a direct photometric microtitration of Sc+++ ion with a 0.001M solution of EDTA using SXO as a metallochromic indicator has been studied. Interferences of different anions and cations on scandium determination are also investigated. Spectrophotometric determination of scandium(III) using SXO at the optimum conditions has been carried out. Beer's law is obeyed for 0–13.49 μg scandium/25 ml.

Spectrophotometric study of reactions of scandium, ytrium and lanthanum ions with some triphenylmethane dyes in the presence of cationic surfactants

Optimum conditions for the formation of ternary complexes of scandium, ytrium and lanthanum ions with chrome azurol S, eriochrome cyanine R and pyrocatechol violet in the presence of cetyltrimethylammonium, cetypyridinium and tetradecyldimethylbenzyl-ammonium (zephiramine) ions are described. The spectrophotometric determination of scandium with chrome azurol S and zephiramine exhibits the greatest sensitivity (ϵ = 1.50 × 10 5 l mol −1 cm −1 at 610 nm). In the spectrophotometric determination of scandium with eriochrome cyanine R and cetylpyridinium ion (ϵ = 9.2 × 10 4 at 600 nm), the interference caused by yttrium is the least. In the best method for yttrium (with pyrocatechol violet and zephiramine), the molar absorptivity is 3.3 × 10 4 at 660 nm. Lanthanum does not form ternary complexes of analytical interest in these systems. Some aspects of the formation of ternary complexes with cationic surfactants are discussed.

The spectrophotometric determination of scandium with disodium 3-hydroxy-4-[(6-methyl-2-pyridyl)azo]-2,7-naphthalenedisulfonate N-oxide

The spectrophotometric determination of scandium with disodium 3-hydroxy-4-[(6-methyl-2-pyridyl)azo]-2,7-naphthalenedisulfonate N-oxide

Spectrophotometric determination of scandium with Chromal Blue G in the presence of cetyltrimethylammonium chloride

Spectrophotometric determination of scandium with Chromal Blue G in the presence of cetyltrimethylammonium chloride

Spectrophotometric Determination of Scandium and Yttrium with Methylxylenol Blue

Spectrophotometric Determination of Scandium and Yttrium with Methylxylenol Blue

The Spectrophotometric Determination of Scandium with Eriochrome Azurol G

The Spectrophotometric Determination of Scandium with Eriochrome Azurol G

The Spectrophotometric Determination of Scandium with Chromal Blue G

The Spectrophotometric Determination of Scandium with Chromal Blue G

Chromogenic Behaviour of Eriochrome Cyanine R.C. in the Spectrophotometric Determination of Scandium, Yttrium and Lanthanum

Chromogenic Behaviour of Eriochrome Cyanine R.C. in the Spectrophotometric Determination of Scandium, Yttrium and Lanthanum

Spectrophotometric determination of scandium with 3,5,7,4'-tetrahydroxyflavone

Spectrophotometric determination of scandium with 3,5,7,4'-tetrahydroxyflavone

The Spectrophotometric Determination of Scandium(III) with Chromazurol S

Abstract Chromazurol S reacts with scandium(III) in a weakly acidic medium to form one of two kinds of complexes according to the pH value of the medium. Their compositions were confirmed; one had a 1 : 2 combining ratio of scandium (III) and chromazurol S at pH 5.2 or higher, and the other, a 1 : 1 ratio at pH below 4.0. The color development of the 1 : 2 complex is more sensitive than the other. Therefore, it was applied to the determination of scandium(III). Several conditions for the color development were investigated, a calibration curve was made under the optimum conditions, and the influences of coexisting ions were investigated. The maximum absorption wavelength of the complex is 550 mμ against the reagent blank. The optimum pH for the color development is about 5.6. By adding a reagent in an amount four times the scandium concentration, the maximum color intensity is given. The color intensity decreases gradually during the first 1.5 hr, and then it remains constant for several hours. A linear relationship between the absorbance and the scandium concentration is obtained in the concentration range from 4 to 27 μg per 10 ml. The value of the molar extinction coefficient of the complex at 550 mμ is 27000, and the sensitivity of the color reaction is 0.0017 μg/cm2 for log I0/I=0.001. The formation constant, K, of the complex is calculated to be 9.5×1011 under these conditions. Anions such as fluoride, phosphate, oxalate, tartrate, citrate, and EDTA interfere with the color development of the complex. Cations such as Al(III), Be(II), U(VI), Fe(II), Th(IV), Cu(II), Y(III), Fe(III), Zr(IV), and W(VI) interfere, too.

Spectrophotometric determination of scandium with bromopyrogallol red

A highly sensitive spectrophotometnc method for scandium with Bromopyrogallolo Red is described;) mierogram amounts of scandium can be determined by measurement 'at 610 mμ and pH 6–1. The molar-absorptivity is 2·4 × 10 4 at 610 mμ. Formation of a 1:1 complex of scandium with Bromopyrogallol Red is confirmed, Common cations interfere, but can be separated completely by three successive ioń-exchange (Steps, so the method can be applied to the determmation of traces of scandium in silicate rocks. Results are quoted for scandiumn in several types of igneous rocks.

Spectrophotometric determination of scandium with naphthyl azoxine S

ナフチルアゾキシンS(NAS)は微酸性においてスカンジウムと反応して420mμに極大吸収を持つ錯体を形成する.この錯体はpH4.5において0.4～3.6ppmの範囲でベールの法則に従う. 420mμにおける分子吸光係数は8×103である。スカンジウム-NAS錯体の組成を連続変化法,傾斜比法,電導度滴定法およびpH滴定法を適用して求めると1:1のモル比が示される.多くの元素が妨害するが,これらは硫酸アンモニウム-硫酸系における陽・陰イオン交換により容易に除去され,ケイ酸塩岩石中の微量スカンジウムの比色定量に本法を適用することができる.

Determination of trace quantities of scandium in silicate rocks by a combined ion exchange-spectrophotometric method

A spectrophotometric determination of scandium in silicate rocks has been developed with arsenazo as the color reagent. After the decomposition of samples with a hydrofluoric-perchloric acid mixture, traces of scandium are separated from interferences by cation- and anion-exchange in acid sulfate media and anion exchange in hydrochloric acid solution. The successive 3 steps, with an intermediate concentration step, yield scandium in a sufficiently pure state for spectrophotometric determination.

Spectrophotometric Determination of Scandium with Oxine or its Dihalogeno-derivatives

スカンジウムをオキシン,5,7一ジクロルオキシンおよび5,7一ジブロムオキシン塩として抽出,吸光光度定量する場合の条件を検討した。オキシン塩はρH8～9,5,7一ジクロルオキシン塩は餌8.5～9。5,5,7一ジブロムオキシン塩はρH8～9の溶液からク冒ロホルムによって定量的に抽出され,クロロホルム溶液はそれぞれ370,397,および402mμに吸収極大がある。各吸収極大波長における分子吸光係数はオキシン塩:5900,5,7一ジクロルオキシン塩=10000,5,7一ジブロムオキシン塩:12000であって,感度の点からは5,7一ジブロムオキシン法がもっともよい。しかし,試薬の溶解性,分析値の再現牲などをあわせ考えると,5,7一ジクロルオキシン法がすぐれている。5,7一ジクロルオキシン法で2～30μ9のスカンジウムが定量できる。共存塩の影響についても調べたが,多くの元素が妨害するので,TTAにより抽出しスカンジウムを妨害元素から分離することを試みた。