Elimination of anionic interference in flame photometric determination of calcium in the presence of phosphate and sulphate

Studies on the interference of phosphate and sulphate in the flame emission of calcium as calcium chloride have shown that there is a fall of intensity corresponding initially to the quantity of the interfering anion, the emission intensity reaching a constant value at a certain ratio of PO₄^-3 or SO₄^-2 to Ca⁺².On addition of appropriate quantities of lanthanum (or iron) to the sample, the intensity of the calcium emission lines is restored to the value it had when the interfering anions were absent.It is postulated that lanthanum replaces calcium in a phosphate- or sulphate-containing compound, that without lanthanum does not form calcium ions even at high temperature.     

Extractive photometric determination of barium and strontium with dimethylsulphonazo DAL

Dimethylsulphonazo DAL, i.e., the dianilide of 2,7-bis(o-sulpho-p-methylphenylazo)chromotropic acid, is proposed as an extractive photometric reagent for determination of trace amounts of barium and strontium.     

The flame photometric determination of calcium in phosphate,carbonate, and silicate rocks

A flame photometric method of determining calcium in phosphate, carbonate, and silicate locks has been developed Aluminum and phosphate interference was overcome by the addition of a large excess of magnesium. The method is rapid and suitable for routine analysis Results obtained are within ± 2% of the calcium oxide content.     

Spectrographic determination of barium and strontium in geological samples

Ohne Zusammenfassung

---

Polarographic determination of Tergitol 08

     

Indirect flame photometric determination of sulphate ions

In this paper the possibilities have been studied of determining sulphate ions by indirect flame photometry by difference. Barium and Strontium in constant concentration were used as background elements. By means of the methods proposed sulphate ions can be determinined in the concentration range 0 to 70 p.p.m. with barium and 0 to 110 p.p.m. with strontium. The determinations can be carried out in dilute solutions of alkali metal sulphates and sulphate ions can also be estimated in the presence of macroquantities of other compounds. This may prove useful for the quantitative estimation of sulphate as an impurity in Chemical reagents. Some examples are given of the determination of the degree of purity of substances containing sulphate as impurities.     

流动注射微分光度法测定钛酸钡烧结物中微量钡

分析速度快、精密度好的流动注射分析技术(FIA),在光度法分析中得到了广泛应用和迅速发展[1-3]。就测试技术而言是在一个非平衡单光束动态检测完成的,而应用双光束检测器建立的分析方法报道很少[4,5]。本文自行研制两组流动比色装置,分别安置在检测器的样品池和参比池,实现了微     

Monohydrates of strontium and barium hydroxide

The monohydrates of strontium and barium hydroxide have been prepared by decomposition, under vacuum, of the corresponding octahydrates. X-ray powder data for both compounds are reported, together with that for anhydrous strontium hydroxide; the latter is included in order to clarify an apparent anomaly in the literature.

---

Zusammenfassung Es wurden die Monohydrate von Strontium und Bariumhydroxid im Vakuum aus den entsprechenden Octahydraten hergestellt. Röntgenographische Daten für beide Verbindungen sowie für wasserfreies Strontiumhydroxid wurden gegeben; für Letzteres, um gewisse Anom alien in der Literatur zu klären.

---

Résumé Préparation des hydroxydes de strontium et de baryum monohydratés par décomposition dans le vide des octohydrates correspondants. Etude par rayons X de ces composés ainsi que de l'hydroxyde de strontium anhydre, dans le but, pour ce dernier, d'élucider certaines anomalies de la littérature.

---

, . , ; , .

---

---

The authors wish to thank Mr. A. Miller for taking the X-ray powder photographs.     

Determination of barium and strontium in sea water

A process based on ion-exchange concentration and separation followed by flame photometry has been developed for the determination of strontium and barium at natural levels in sea water. These elements are stripped from 1-I samples of sea water by means of a cation-exchange resin in the calcium form and selectively eluted with CyDTA and EDTA respectively. Factors influencing the intensity of strontium and barium in hydrogen flames have been studied. The standard deviations of the method are 0.05 p.p.m. for strontium and 0.6 p.p.b. for barium and the accuracy of the method is more than sufficient to demonstrate clearly the variability of Sr/Cl and Ba/Cl ratios with depth and location     

The photolysis of barium and strontium azides

The effect of very high intensity UV light on powdered barium and strontium azides in vacuo in the temperature ranges −70° to 100°, and −80° to 90°, has been studied. The photolytic decompositions were characterized by a high percentage decomposition and sigmoid pressure vs time plots similar to those obtained by thermal decomposition. Kinetic analysis, the determination of activation energies, studies of the dependence of reaction rates on light intensity, and the effect of water vapour, were carried out. Mechanisms for decomposition over well defined temperature ranges are proposed.     

The flame photometric determination of alkali metals, alkaline earths and copper in nuclear grade uranium

Summary A method, which involves prior chemical separation of uranium from impurities by tributylphosphate extraction, is described for the determination of alkali metals, alkaline earths and copper in nuclear grade uranium. The characteristic emission lines, excited in hydrogen-oxygen flame, are isolated by a small monochromator and recorded photoelectrically.Using 3 g samples 0.005 ppm of Li, 0.001 ppm of Na, 0.05 ppm of K, 1 ppm of Mg, 1.5 ppm of Ba and 2 ppm of Cu can be determined in uranium, with reproducibilities better than ± 3%.Some interelemental interferences are discussed, and the possibilities of their elimination are described.The method can be used without modification for the analysis of uranium containing up to 100ppm of impurities.

---

Zusammenfassung Es wird ein Verfahren zur flammenphotometrischen Bestimmung von Alkalien, Erdalkalien und Kupfer in Uran von nuklearem Reinheitsgrad beschrieben, das eine vorherige Extraktion des Urans mit Tributylphosphat verwendet. Die charakteristischen Emissionslinien werden durch eine Wasserstoff-Sauerstoff-Flamme angeregt, durch einen kleinen Monochromator isoliert und photoelektrisch registriert. Mit einer Probe von 3 g können noch 0,005 ppm Li, 0,001 ppm Na, 0,05 ppm K, 1 ppm Mg, 1,5 ppm Ba und 2 ppm Cu mit einer Reproduzierbarkeit von <± 3% bestimmt werden. Störungen durch andere Elemente sowie Möglichkeiten zu ihrer Ausschaltung werden diskutiert. Das Verfahren kann bis zu einem Gehalt von 100 ppm an Verunreinigungen in Uran angewendet werden.

---

---

On leave to the IAEA Vienna, Austria.     

The photometric determination of Copper by extraction as the Diethyldithiocarbamate. Interferences and their Elimination

Summary Two procedures for the photometric determination of copper as the diethyldithiocarbamate complex have been investigated as to their selectivity.In the first procedure—extraction by chloroform from a citrate solution ofph about 8.5, containing EDTA—the following elements interfere: Hg^II, Ag, Au, Pt, Pd, Os, Sb^III, Te^IV, Tl^III and Bi. Interference by Hg^II, Ag, Pd, Sb^III, Te^IV and Tl^III can be prevented by simple measures.In the second procedure—extraction by a solution of lead diethyldithiocarbamate in chloroform from ammoniacal citrate-only Ag, Tl^III, Bi and Hg^II interfere. Interference by the first three elements can be prevented easily, leaving as the only serious interference in this method mercury in amounts above 500 g.     

Simultaneous determination of lithium, sodium and potassium in blood serum by flame photometric flow-injection analysis

A simultaneous flow-injection analysis (FIA) manifold that could analyse three ions from a single injection was designed, constructed, calibrated and used successfully to analyse Li(+), Na(+) and K(+). This FIA method was 10 times faster than the batch technique. The sample volume required was a fraction of about 1/110 to 1/75 that of the batch technique. The outputs were quite reproducible and calibration curves were linear. Results obtained for artificial sera compared favourably with the actual known concentrations of ions and results obtained in the analysis of eight natural human blood sera compared well with those obtained by the traditional batch technique.     

Application of displacement reactions in flame photometry-II Emission flame photometric determination of alkaline earth metals in the presence of interfering anions

For the emission flame photometric determination of strontium and barium in the presence of interfering ions such as phosphate, sulphate, arsenate and oxalate, calibration or simple standard addition methods cannot be used. Greatly reduced errors can be achieved by dividing the sample solution into four equal parts and adding to each certain known amounts of two metal ions. One of these is identical to the determinand (e.g., strontium or barium) the other has similar characteristics to it (e.g., calcium). The amounts of these metals are chosen so that the total (molar) concentration of these should be identical in all solutions, but the ratio of the concentrations of the two metals should be different. The emission of the determinand metal must be measured, and a standard addition plot produced. The amount of determinand present in the sample can be obtained from the intersection of the emission vs. concentration line with the concentration axis.     

Infrared determination of barium, strontium, sodium and potassium sulphates by the pellet technique

Methods are proposed for the infrared determination of barium, strontium, sodium and potassium sulphates by the pellet technique. The semimicro sample is mixed with 300 mg of potassium bromide, the pellet is formed, and the peak heights are determined at the appropriate peak. Barium and strontium sulphates are measured at 983 and 993 cm(-1), respectively. Sodium and potassium sulphates are both measured at 619 cm(-1). Barium and strontium sulphates can be determined in the presence of each other in ratios from 1:20 to 20:1 from the measurements at 983 and 993 cm(-1). Carbonates or nitrates do not interfere with any of the procedures.