Spektrofotometrische bestimmung von calciumspuren nach ihrer abtrennung aus konzentrierten Lithiumchlorid-Lösungen mittels kationenaustausch

Calcium was separated from 1–2 M solutions of lithium chloride by means of Wofatit CP cation exchanger. Calcium was quantitatively separated from lithium by elution with 1 M ammonium chloride. Calcium, was eluted with hydrochloric acid and, eventually, measured spectrophotometrically at 567 mμ after addition of buffer and cresolphthalexone. The sensitivity was found to be 0.002 μg Ca/cm2 and Beer's law was obeved up to 15 μg Ca. With l g of lithium, the limit of determination was 10^-4% Ca.     

Die klassischen Verfahren der Analyse von Steinsalz und Salzsole

Ohne Zusammenfassung     

Einen Vergleich von Destillations- und Extraktionsmethoden zur Abtrennung Spuren von Germanium aus Mineralien und Kohlen

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Einen Vergleich von spektrochemischen und Semimikromethoden bei der Analyse von Petroleumaschen

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Nachweis und Bestimmung der Nitrierungsprodukte von Diphenylmethan mittels NMR-Spektrometrie

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Untersuchungen zur atomspektroskopischen spurenanalyse in AIIIBV-halbleiter-mikroproben—IV: Vergleich der bestimmung von tellurspuren im GaP und GaAs durch AAS,AFS und AES

Methods are described for the determination of trace tellurium in acid solution in the absence and presence of the inorganic matrices As, P, Ga, GaP and GaAs and for the direct determination in solid GaP and GAs. The following methods were used: AAS with electrothermal atomization, AFS with electrothermal atomization, and AES with d.c. arc excitation. The conditions for each of the methods were optimized and the analytical results were compared. It is shown that AAS with electrothermal atomization gives the best absolute and also relative limit of detection for trace tellurium (90 pg Te, or 4 ppm Te in GaAs or GaP). Therefore this method is recommended for the determination of trace tellurium in very small samples of A^IIIB_V-semiconductors.     

Vergleich der Eigenschaften von elektrolytisch hergestellten und von handelsüblichen Halogenidelektroden

The preparation of chloride, bromide and iodide electrodes by electrolytical coating of silver rods has been described. These electrodes show at least as good characteristics as commercially available halide electrodes. Main advantages of the coated types are simple preparation, mechanical robustness and easy regeneration. Due to the lack of any cemented areas or electrical contact points, the use of these electrodes is mostly free from interferences.     

Die Verwendung von Brom bei der Arsentrioxyd- und Antimon bestimmung und doe Winklersche Bromjodzahlbestimmung

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Fraktionierte Kristallisation von Ammonium- und Magnesiumdoppelnitraten der Ceriterden; Bestimmung der Trennfaktoren und Vergleich der Trennwirkung

Summary The Separation Factors for Pr/La, Nd/Pr, and Sm/Nd, characterizing the crystallization of ammonium and magnesium double nitrates under practical conditions, were determined analytically and are discussed. They confirm that La and Pr can be separated better by fractional crystallization of ammonium double nitrates, whereas in the presence of Sm the magnesium double nitrates are preferable.

     

Zur bestimmung von natrium- und lithiumbenzoat

Ohne Zusammenfassung     

Oszillopolarographischer nachweis und bestimmung von jodat und perjodat

The oscillopolarographic behaviour of periodate and iodate has been investigated in acid, neutral and alkaline electrolytes. The detection and determination of periodate in iodate may be carried out using iodate as electrolyte and the detection and determination of iodate in periodate may be carried out using 5 M sodium hydroxide as electrolyte.     

Absolute bestimmung der molekulargewichtsverteilung von anionisch und radikalisch polymerisierten polystyrolen durch lichtstreuung

The scattering function P₀ for classical elastic light scattering is specified for several molecular weight distribution functions (Schulz-, Square root-, Maxwell-, Normal-, Poisson-, Logarithmic-normal-distribution function). Precision measurements on anionic polymerized polystyrene from Pressure Chemical Co. $\text{(}\text{M}{}_{\mathrm{w}}\text{= 2 · 10}{}^6\text{and}\text{M}{}_{\mathrm{w}}\text{= 6,7 · 10}{}^6\text{)}$ and radical initiated polystyrene were performed in transdecalin with the light scattering photometer Fica 50. Comparison of experimental results with theoretical curves indicate that the anionic polystyrenes exhibit a broader distribution than given by Pressure Chemical Co. The distribution of the radical polystyrene conforms with distributions found by other methods.     

Atomabsorptions-spektrometrische bestimmung kleiner substanzmengen und analyse von Spurenkonzentrat-mit der “Injektionsmethode”

Characteristics and potentialities of the ‘injection method’ described by Sebastiani, ohls and riemer were examined for the determination of small amounts of substances and for the analysis of concentrates of trace elements. The dependence of the peak height of the analytical signal from the injected volume, damping and solution flow rate of the nebulizer was studied and optimum conditions for the AAS-determination of 11 elements in a total volume of 1 ml were established. For each volume injected there is an optimal value for the solution flow rate, where the maximum concentration sensitivity for this volume is reached. Reduction of the volume of the sucked amount of sample from 0.5–1 ml (continuous sucking) to 40?100μl (injection of sample) improves the mass sensitivity and the mass detection limit for each element by a factor 7. The relative standard deviation of this method was found to be about 0,05.