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The spectrophotometric titration of magnesium, calcium, strontium, and barium, in the visible and ultra-violet regions of the spectrum, has been investigated and a method is presented for the determination of small amounts of these elements by spectrophotometric titration using Eriochrome Black T as indicator, after separation by paper chromatography and removal from the paper with dilute hydrochloric acid. The minimum amount of each cation determined was 0.5 μ M and the procedure was applied successfully to the analysis of a dolomite, a strontianite, and a barytocalcite.

(1) Carrier-free yttrium-90 can be separated rapidly and simply from strontium-90 by paper chromatography. The most suitable solvent is a mixture of ethyl alcohol and 10% solution of ammonium thiocyanate (5:3 or 5:2). The Rf value of carrier-free yttrium-90 is 0 and that of strontium is 0.7 to 0.8. (2) Carrier-free yttrium-90 having a radiochemical purity more than 99.9% can be prepared within forty minutes. (3) If yttrium-carrier is present, when it is developed with the above mentioned solvent, it is distributed upward from the original position on the paper. Its distribution pattern depends upon the amount of yttrium-carrier and the developing time and it may be caused by the adsorption of yttrium on the paper.

A procedure has been devised whereby three alkaline earth metal ions - magnesium, calcium, and strontium - resolved on paper chromatography can be analyzed by means of in situ fluorometry. The procedure makes it possible to determine the concentration of adsorbed alkaline earth metal at μg level and lower with a precision of about 2%.

Summary The separation of Ca-Sr-Ba was achieved by paper chromatography using concentrated nitrate solutions with propanol as solvent. Ba yields double spots with some organic solvents. The method enables a separation of Ba and Ra in trace amounts and is useful for the radiochemical purification of 140 Ba and 228 Ra sources.

A specific, sensitive, and simple method of simultaneously determining calcium and strontium in biological material is described. Samples are burned in a closed atmosphere of oxygen, then taken up in dilute HNO/sub 3/. An aliquot is submitted to ascending paper chromatography. Calcium and strontium are separated from each othe-r, then recovered by calcination. Both elements are estimated by complexometric microtitration with EDTA, using calcein as indicator. Amounts of 25 x 10/sup -9/M calcium and strontium are quantitatively recovered to within 1 to 2% and can be determined with a coefficient of variation of about 5%. For larger quantities, the reproducibility ranges from 1 to 4%. (auth)

The chromatographic behaviour of alkali and alkaline earth metals on paper treated with di(2-ethylhexyl) phosphoric acid (HDEHP) has been investigated, using acetic acid as the eluent in the range of concentrations from 2 M to 0.01 M . The quantity (1/ RinF — 1) has been related to the hydrogen ion concentration and to the effective HDEHP concentration on the paper. A behaviour similar to that show in liquid—liquid extraction with HDEHP solutions was found, provided that the acetic acid concentration was kept low. The peculiar behaviour shown with concentrated acetic acid has been discussed. No direct proportionality has been obtained between the HDEHP molarity in the solution used to treat the paper and the effective concentration of HDEHP on the paper which acts during elution. The instability of HDEHP on paper with very concentrated acetic acid has been also investigated. Some chromatographic separations of alkali and alkaline earth metals have been carried out, and others have been suggested.

Reversed-phase chromatography of alkaline earth metals on paper treated with di-(2-ethylhexyl) orthophosphoric acid (HDEHP) has been investigated, using hydrochloric acid as eluent in a range of concentrations from 10 M to 1 · 10 −4 M . The quantity (I R F —1) has been related to the hydrogen ion concentration in the mobile phase, and to the effective HDEHP concentration on the paper. The chromatographic behavious has been correlated with that of liquid—liquid extraction systems. Chromatographic separations of alkaline earths from each other, and from other cations, were performed. Two of them were obtained with acetic acid elutions.

Reversed-phase chromatography of aluminium, gallium, indium, thallium and the transition metals of the iron group on paper treated with di-(2-ethylhexyl) orthophosphoric acid (HDEHP) has been investigated, using hydrochloric acid as eluent in a range of concentrations from 10 M to 1 · 10−4M. The quantity (i/RF — 1) has been related to the hydrogen ion activity in the mobile phase and to the effective HDEHP concentration on the paper. The chromatographic behaviour has been correlated with that in liquid-liquid extraction systems. Chromatographic separations of the above elements from each other and from additional cations such as barium, calcium, titanium, strontium, manganese, yttrium, zirconium and uranium were performed.

A method is outlined for the quantitative transfer of nuclides of strontium, barium, cerium, zirconium, lanthanum, yttrium, and niobium from solution to a paper for Chromatographic separation. Carrier quantities of iron are precipitated as the hydroxide from a carbonate solution and filtered directly onto the Chromatographic paper. A two-dimensional development is utilized to isolate the individual nuclides. This separation procedure is applied to air dust samples containing nuclear debris. Radiometric determinations may be conveniently made by γ-spectrometric or conventional low-background β-measurements.

The chromatographic behavior of beryllium, magnesium, calcium, strontium and barium was investigated on Whatman No. 1 paper impregnated with di- n -butyl phosphate (HDBP) as the stationary phase. Elution was performed with hydrochloric acid in a concentration range 1·10 −3 –10 M . The chromatographic data obtained for Be 2+ and Ca 2+ were interpreted by means of plots of log (1/ R F — 1) vs . log [H+], or versus the amount of HDBP fixed on the paper. From these plots apparent stability constants for the formation of metal complexes were determined using a simple correlation between the liquid-liquid extraction coefficient and the (1/ R F — 1) function in reversed-phase partition chromatography. By a convenient choice of the concentration of hydrochloric acid in the mobile phase and that of HDBP in the stationary phase, separation of alkaline earths and their separation from other cations can be achieved.

A number of separations are described in which paper electropheresis is used in combination with the appearance of electrochemically generated basic and acidic zones at the electrodes. By choice of the proper electrolyte solutions, with or without complexing properties, a simple method has been devised which makes possible the rapid separation of certain ion combinations. Complete separations of 90Sr and 90Y; 137Cs and 137Ba; 208Tl 212Bi and 212Pb and an incomplete separation of 210Po from 210Bi and 210Pb have been achieved.

The mobilities of Co/sup 60/, Sr/sup 90/ Cs/sup 134/, Ce/sup 144/ and Eu/ sup (+Eu/sup 154/), as a function of pH in 1% citric acid solutions of their carrier-free chlorides, were studied. Cesium ion, which migrated toward the cathode, decreased in mobility linearly as the pH increased. Strontium ion had an electromigration behavior similar to that of Cs ion up to pH 5 then changed the direction of migration toward the anode at pH 4.5; Co and rare earth ions, having a similar behavior, changed their ionic charge at pH 2.2 and 3.2, respectively. By taking advantage of this behavior, Cs could be separated from bi- and tervalent metal ions at any pH values, whereas Y could be separated from Sr ions, and rare earth from Co ions only at low pH values. The separation of Y/ sup 90/ from Sr/sup 90/ was effectively carried out in an 80% alcoholic solution of citric acid. After electrophoresis for 2 hr, Sr migrated 20 cm while Y moved only 2 cm. Cerium and Eu behave similarly to Y. Their migration distances decreased with increasing pH values; they changed their ionic charge at pH 2.7, migrated toward the anode, and then their mobilitymore » gradually decreased above pH 5. At higher pH values in the acid region, however, Eu showed slightly greater velocity than Ce. This slight difference may be useful in the separation of Ce, Eu, and Y at higher field strengths and prolonged times of operation. Although the radioactivity maxima of Ce and Eu separate by 1 cm from each other, these rare earths diffuse widely to about 4 cm on the paper strips; therefore, quantitative separation of these 2 metals under the present experimental conditions was not possible. The short-lived Pr/sup 144/ could not be detected in the electrochromatograms of Ce/sup 144/, because the daughter decayed almost completely as soon as it is separated. It is reasonable to expect that Pr would be located between Ce and Eu. (BBB)« less

The differences of the elastic constants of strontium molybdate from those of calcium molybdate and calcium tungstate are investigated. A useful check on the measured velocities at a given angle to the z-axis for materials of tetragonal symmetry is illustrated. An inconsistency in the measured velocities in the xy plane is discussed. A new set of elastic constants has been calculated for strontium molybdate. Es wird die Differenz zwischen den elastischen Konstanten von Strontiummolybdat und denjenigen von Kalziummolybdat und Kalziumwolframat untersucht. Eine nutzliche Uber-prufung der gemessenen Geschwindigkeiten eines gegebenen Winkels zur z-Achse tetragonal symmetrischer Materialien wird illustriert. Eine Inkonsequenz in den gemessenen Geschwindigkeiten an der xy-Ebene wird untersucht. Eine neue Folge der elastischen Konstanten von Strontiummolybdat wurde berechnet.

The migration order of strontium and barium ions in aqueous citric acid solutions was reversed and the complete separation was found to be possible by the addition of methanol, ethanol, or isopropanol. The relative velocity of strontium to barium ions increases with the increasing proportion of alcohols to aqueous solutions. Separation of these ions from each other has been carried out at the field strength of 10, 20, and 37 volt/cm. At 37 volt/cm, strontium and barium ions were separated completely within 1, 2.5, and 6 hours in 80% methanol, ethanol, and isopropanoi solutions, respectively. The migration distances of strontium and barium ions in these solutions have been found to be 16.5, 13.2; 21, 12 and 24, 15 cm, respectively. The readiness for the separation depends on the use of solvents and decreases in the order of methanol, ethanol and 2-propanol. The increase in partition coefficients is attributed to the addition of alcohols.

テトラオキシキノンナトリウム試験紙を用いるバリウムおよびストロンチウムの新しい特異的検出法について検討した.検液の1滴を試験紙上に点滴し,呈色した試験紙を4%シュウ酸アンモニウム溶液に浸すと,バリウムによる呈色は変化なく,ストロンチウムによる呈色は脱色した.また,呈色した試験紙を5%硫酸カリウム溶液中に浸すと,ストロンチウムによる呈色は変化がないが,バリウムによる呈色は消失し,両イオンを区別することができた.また,重金属イオンが共存する場合には,ジエチルジチオカルバミン酸ナトリウムを用いて,簡易に重金属の妨害を除去することができた.

Summary The electrical conductivity due to sodium, barium, and strontium has been investigated in H2-O2 and C3H3-O2 flames at a total pressure of 1 atm and the temperature range 1400° to 2200°K. Both sodium and barium have an ionization potential of approximately 5·1 eV. Flames seeded with barium acetate had a higher conductivity (an order of magnitude at 1800°K) than those with sodium hydroxide. Flames seeded with strontium also had conductivities higher than can be due to the ionization of the alkaline earth metal. The emission limit of graphite electrodes was markedly improved with barium seeded flames compared to the limit found with flames seeded with potassium.