Séparation des alcalino-terreux par chromatographie sur colonne de cellulose

A good separation of tracer amounts of. Ca- Sr- Ba- Ra could be obtained by chromatography on a cellulose powder column on using successively the following two eluants: 1. Methanol-ether-HCl 12N (v/v: 75-25-5) (Ca, Sr). 2. Methanol - HCI 12N (v/v: 100-5) (Ba, Ra). Eluant 1, which has already been proposed for the separation of Ba and Sr in tracer amounts. is well suited for the separation of Ca Sr (carrier free) A further test of this eluant for the separation of ⁸⁹Sr-¹⁴⁰Ba, obtained carrier-free, from an irradiated uranium nitrate sample, proved to be successful.Eluant 2, gives a satisfactory Ba- Ra separation (Ba either carries free or not) and may be used for a rapid preparation of mesothorium 1 -sources (²²⁸Ra), free from barium; it is also recommended for the purification of small quantities of radium.     

利用锶特效树脂分离富集岩石样品中的锶及测定~(87)Sr/~(86)Sr

本研究以Sr-Spec树脂作为分离锶的特效树脂,以HNO3为淋洗液,通过改变HNO3的浓度,将地质岩石样品中的锶分离富集.实验结果表明,Sr与基质元素和Rb能很好地分离.利用Sr-Spec树脂分离国际标准物质SRM607、日本岩石标样JA-2、JB-2、JF-2和国家标准物质GBW04111后, 测得同位素比值87Sr/86Sr结果及误差(2σ)分别为1.200660±22, 0.706350±17, 0.703640±16, 0.709692±22和0.700008±23.相对于常规的阳离子树脂分离方法,此方法所用淋洗试剂量少,分离流程短,可以降低实验空白并提高工作效率.因此,Sr-Spec树脂分离法是快速分离富集不同岩性地质样品的Sr并测定87Sr/86Sr的有效方法.     

Chromatographische trennung von metallionen durch elution mit ammoniumsulfat: Bestimmung von magnesium,calcium und strontium in salzreichen wässern

The chromatographic separation of Mg, Ca, Sr, Ba, Fe(II, III) and Mn(II) by elution with ammonium sulphate solution from Dowex 50–X₁₀ was studied. The optimum conditions for the separation of the alkaline earths from each other were established. The method was applied for the separation of Mg, Ca and Sr in salt waters; Mg and Ca were determined by EDTA titration and Sr spectrographically, the coefficient of variation being 1.9% for Mg and 1.4% for Ca.     

Separation of strontium from associated elements with selective specific resin and extraction chromatography

In this paper,separation of Sr from associated elements（Na,K,Ca,Mg,and Ba） was carried out using an extraction chromatographic column packed with Sr selective specific resin consisting of an octanol solution of 4,4’（5’）-bis（t-butylcyclohexo）-18-crown-6 sorbed on an inert polymeric support.Using 8.0 mol/L HNO₃ as the eluent,Ba and associated elements were eluted immediately from the column, whereas Sr was strongly retained.The adsorbed Sr could then be stripped from the column as the eluent was changed to 0.05 mol/L HNO₃.Complete Sr/Ba separation was demonstrated to be feasible in that Ba could be washed from the column leaving pure Sr by adequate rinsing with 8.0 mol/L HNO₃. Furthermore,matrix effect could be effectively eliminated and the selectivity of the method was improved.The method was applied for the determination of Sr in the high purity barium carbonate （BaCO₃） product and seawater.The recoveries of Sr in 2 samples were determined to be 93.2%and 109%, respectively.     

Use of Extraction Chromatography, Ion Chromatography and Liquid Scintillation Spectrometry for Rapid Determination of Strontium-89 and Strontium-90 in Food in Cases of Increased Release of radionuclides

For rapid determination of ⁸⁹Sr and ⁹⁰Sr in food, isocratic ion chromatography used for Sr isolation and purification is integrated in a complete analytical system comprising sample preparation, incineration, dissolution, phosphate precipitation for alkali/alkaline carth separation, and Sr specific extraction chromatography on crown ether basis for Ca/Sr separation. Strontium-89 and ⁹⁰Sr are determined by liquid scintillation spectrometry after carbonate precipitation. The components of the mixed spectra obtained are calculated by the computerized spectra subtraction method. Two days plus measuring time are required for single, three for double analysis. The limit of detection for ⁸⁹Sr and ⁹⁰Sr is ca. 0.1 Bq·kg^–1, related to the fresh produce.     

La1—xMxCoO3（M=Ca,Sr）表面状态的XPS研究

合成了一系列钙钛矿复合氧化物La_(1-x)M_(?)CoO_3(M=Ca,Sr),并用XPS研究了LaCoO_3中的La~(3+)部分被Ca~(2+)或Sr~(2+)取代后表面状态的变化。由XPS的O_(10)谱图拟合得到的吸附氧O(2)百分数与取代量x呈现规律性变化。对Ca_(2p)与Sr_(3d)谱图也进行峰拟合处理,其中结合能较高的Sr(2)、Ca(2)可指认为周围有氧离子缺位物种。Ca(2)或Sr(2)百分数与吸附氧百分数的关系可用取代后表面状态的变化来解释。     

Retention of alkali,alkaline earth and transition metals on an itaconic acid cation-exchange column. Eluent pH,ionic strength and temperature effects upon selectivity

The unusual selectivity of a methylene succinic (itaconic) acid modified polymeric column was investigated for the separation of alkali, alkaline earth, transition and heavy metals employing non-chelating inorganic eluents. The retention of selected metal ions on the column was investigated with simple HNO3 eluents and eluents prepared from KNO3 and KCl salts of varying pH (adjusted using HNO3). From these studies both the effect of eluent ionic strength and pH upon retention was evaluated for the itaconic acid stationary phase. The results obtained showed that despite slow exchange kinetics causing poor efficiencies, acceptable baseline separations of selected alkaline earth and transitions could be obtained under optimum conditions (the baseline separation of Mg(II), Ca(II), Mn(II), Cd(II), Zn(II) and Co(II) was possible using a 15 mM KNO3-5 mM KCl eluent at pH 3.50 in under 25 min). The use of an simple ionic strength step gradient was shown that facilitated the addition of Pb(II) to the above group of metal ions. An investigation into the effect of temperature upon peak efficiency and retention showed increased column temperature could be used to improve the resolution of closely eluting metal ions such as Ca(II) and Sr(II) and Ca(II) and Mn(II).     

The extraction behavior of some dicarbollylcobaltate crown extraction systems

The extraction of cesium, strontium and barium by a nitrobenzene solution of dicarbollylcobaltate in the presence of various crown ethers has been investigated and the influence of the substituent of crown to the extraction possibility has been observed. It has been found, that the addition of DB15C5, DB18C6 and DB21C7 (but not DB24C8 and DCH24C8) increases the distribution ratio of Cs by one order of magnitude. The fivemembered crowns are usually more efficient extractants for strontium than DCH18C6, which is widely used for strontium separation. The distribution ratio of strontium D_Sr decreases in the order 15-crown-5>benzo-15-crown-5>2-hydroxymethyl-15-crown-5>cyclohexyl-15-crown-5 >dibenzo-15-crown-5> nitrobenzo-15-crown-5. The selectivity α(Sr/Ca) decreases in the order 15C5>B15C5>DB15C5>2HM15C5>CH15C5. A selectivity factor α(Sr/Ca)≥1000 can be reached in the presence of 15C5 and B15C5. Six-membered and four-membered crowns extract strontium worse than most of the five-membered crowns. The selectivity factors α(Sr/Ca)≈100 have been reached for six-membered crowns and α(Sr/Ca)<1 has been found for 12C4. The extraction of barium by a nitrobenzene solution of dicarbollylcobaltate in the presence of 15C5 is even more efficient as the extraction of strontium. In that system D_Sr>10⁴ and D_Ba>10⁴ have been found for the extraction of Sr and Ba by a 0.01M nitrobenzene solution of dicarbollylcobaltate (c_B=0.01 mol/l) from 0.1M HNO₃. Maximal values of separation factor α(Ba/Sr) have been found in the system containing DB21C7.     

Methodology for determination of <Superscript>89</Superscript>Sr and <Superscript>90</Superscript>Sr in radiological emergency: II. Method development and evaluation

In this work a method for the determination of both ⁸⁹Sr and ⁹⁰Sr is presented. The method can potentially be used in radiological emergency and deliver results shortly after an incident. The method development was based on theoretical calculations of potential interferences from other fission products and how these could be discriminated when applying different chemical separation schemes. Validation was done on reactor coolant water containing short-lived fission products, and on a reference material. The results indicate that correct results of ⁸⁹Sr and ⁹⁰Sr can be obtained 4 and 9 days, respectively, after an incident.     

人牙齿中锶的特效树脂分离及其同位素测定

采用锶特效树脂(Sr-Spec)建立了快速分离富集人牙齿中微量元素锶,并测定87Sr/86Sr的有效方法。采用HNO3-HClO4体系消解牙齿样品,以8mol/L HNO3为介质上柱,8mol/L HNO3淋洗,0.05mol/LHNO3洗脱,收集淋洗液,蒸干;采用正热电离质谱法进行87Sr/86Sr的测定。结果表明,利用Sr-Spec树脂,不仅能将锶与基质中大量钙分离,并能有效分离同位素测定中干扰元素铷。本方法可以缩短分离时间,提高分离效率,减少试剂用量,降低实验空白。采用本方法对陕南地区人牙齿牙釉质中锶进行分离,测得的87Sr/86Sr值在0.710948～0.711037之间。     

Optimization of Sr-90 precipitation in nitric acid using design of experiments for radioactive waste characterization method

Journal of Radioanalytical and Nuclear Chemistry - 90Sr radiochemical method using nitric acid for Sr and Ca separation was optimized using design of experiments methodology. Nitric acid...     

Growth and Spectral Characterization of Nd3+∶(Sr0.7Ca0.3)3Y(BO3)3 Crystal

A Nd3+ :(Sr0.7Ca0.3)3Y(BO3)3 crystal with dimensions of 17×23 mm3 has been grown by the Czochralski method. The spectroscopic characterization of Nd3+ :(Sr0.7Ca0.3)3Y(BO3)3 crystal was investigated. The polarized absorption cross-sections of Nd3+ :(Sr0.7Ca0.3)3Y(BO3)3 crystal are 2.81×10-20 cm2 with full width at half maximum (FWHM) of 14 nm at 808 nm for σ-polarization and 2.04×10 -20 cm 2 with FWHM of 19 nm at 807 nm for σ-polarization, respectively. The polarized emission cross-sections of Nd3+ :(Sr0.7Ca0.3)3Y(BO3)3 crystal are 12.2×10-20 cm2 at 1062 nm for the π-polarization and 13.6×10-20 cm2 at 1061 nm for the σ-polarization, respectively. After the Ca 2+ ion partly substitutes for Sr2+ ion in the Sr3Y(BO3)3 crystal to form the (Sr0.7Ca0.3)3Y(BO3)3 solid solution, it can improve the quantum efficiency of Nd3+ :(Sr0.7Ca0.3)3Y(BO3)3 crystal. The quantum efficiency is 31.7%. These results may be regarded Nd3+ :(Sr0.7Ca0.3)3Y(BO3)3 crystal as a potential solid-state laser material.     

石墨炉原子吸收光谱测硼时基体改进剂的选择

研究各种基体改进剂的增感效果,和它们对灰化、原子化温度的影响。结果表明,Ca、Sr、Ca-Mg、Ca-La、Sr-Mg均可作为硼的基体改进剂,且Ca-Mg、Ca-La、Sr-Mg较之Ca、Sr性能优越。并分别以Ca、Ca-Mg、Sr-Mg作基体改进剂,直接分析饮用水中痕量硼,所得结果基本一致,相对标准偏差均在10%以内。     

Chromatographische trennung von calcium und strontium durch elution mit ammoniumsulfatlösung

A method is described for the chromatographic separation of calcium and strontium adsorbed on a cation-exchange resin, by means of elution with ammonium sulphate solution. The method is suitable for Ca : Sr ratios ? 1. The separated elements can be determined directly in the eluate.     

等离子体质谱法测定珊瑚锶和钙

研究了珊瑚中Ｓｒ（～８０００ｕｇ／ｇ）、Ｃａ（～４００ｍｇ／ｇ）在同一份溶液中的等离子体质谱的同时测定。所有样品均加入Ｓｃ和Ｙ作内标元素分别控制测定Ｃａ和Ｓｒ时的仪器波动。本方法Ｓｒ、Ｃａ测量精度（ＲＳＤ％）分别～０．３％、～１％。９０个珊瑚样品Ｓｒ分析结果中,仅有７个样品Ｓｒ数据与同位素稀释热电离质谱法数据相比,相对偏差较大（～１％）,其它数据相互吻合。本方法适合珊瑚样中Ｓｒ的快速测定,并可以此     

Separation of Cs and Sr using polyoxonium compounds

Extraction separation and concentration of Cs and Sr from aqueous solutions, containing macroconcentrations of competitive ions (Li⁺, Na⁺, K⁺, Mg²⁺, Ca²⁺, Al³⁺, Fe³⁺) by the nitrobenzene solutions of bis-1,2-dicarbollylcobaltate in the presence of linear and cyclic polyoxonium compounds (POC) has been investigated. It has been found, that the addition of DB18C6 increases the distribution ratio of cesium (D_cs) but the addition of other crowns and PEG decreases D_Cs value and selectivity of D_Sr and the selectivity of Sr/Ca separation. Separation factors of Sr/Ca increase from (Sr/Ca)2 (found in the absence of POD) to (Sr/Ca)50 (for DB18C6), (Sr/Ca)100 (for 18C6 and DCH18C6) and (Sr/Ca)1000 for 15C5.     

Simultaneous determination of alkali, alkaline earths and ammonium in natural waters by ion chromatography

An ion chromatographic method has been developed for the determination of alkali (Li(+), Na(+), K(+)), alkaline earths (Ca(2+), Mg(2+), Ba(2+), Sr(2+)) and ammonium ion in waters. The usual difficulties encountered during traditional cation-exchange separations (incomplete resolution for Na(+) and NH(4) (+) present in disproportionate concentration ratios) have been overcome tuning the selectivity of the separation by the introduction of 18-crown-6 ether in the mobile phase using an IonPac CS12A (150x3 mm id) column. After a detailed study of the effect of mobile phase components on separation, a gradient elution from 26 mM methanesulphonic acid (MSA) with a step change at 9 min to 60 mM MSA (0.5 mM 18-crown-6) provided the required baseline separation for the eight selected analytes. The method developed provides the advantage of the determination, in the same analytical run, also of strontium and barium, which is usually performed by spectroscopic techniques. Within-day and between-day repeatability have been assessed, observing between-day RSD included between 0.3 and 1.8% for retention times and 0.6 and 7.2% for peak areas. The method has been finally tested for the analysis of water samples of different provenience (well, tanks, water system) and results compared with those obtained by the laboratory in charge of the control of drinking water for the city of Torino (Italy).     

An emulsion membrane extraction of strontium and its separation from calcium utilizing crowns and picric acid

The selective separation ability of the cyclic crowns, known for liquid-liquid extraction, e.g. alkali metals, is found to be effective for emulsion membrane extraction. 18-C-6, DB-18-C-6, DC-18-C-6 crowns were used as carriers. The co-transport of the ionic pair SrL²⁺. 2A through the membrane has been studied. Calcium was considered as a main competing ion. Even in the case of 20-fold preconcentration, there have been found conditions under which the pertraction process can reach Sr/Ca separation factors of about 500 and the yield of strontium is high (95–98%). The presence of calcium up to 1000-fold excess has no influence on the yield of strontium (1.10^–5M). The calcium content in the isolated emulsion was caused by second emulsification of the outer solution. The influence of potassium on strontium pertraction has been studied and some transport data of Cs and Y have been obtained.     

Separation and analysis of aluminium(III) by cation exchange ion chromatography

A method for the determination of aluminium(III) ions based on separation by cation exchange column chromatography and detection by conductivity detector has been developed. It is fast and reliable, and can be used for the separation and analysis of aluminium(III) ions from other metal ions like Mg(II), Mn(II), Zn(II), Co(II), Ca(II), Sr(II), rare earth elements like Lu(III), Tm(III), and Gd(III), which are eluted at different times and so do not interfere. Effect of p-phenylene diamine concentration present in the eluent, presence of other metal ions and effect of various anions present in the injection sample on the separation and analysis of aluminium(III) ions have also been studied.