Thiolactame als Reagenzien in der quantitativen Analyse. IX

Zusammenfassung Thiocaprolactam (T) eignet sich zur Goldbestimmung im Konzentrationsbereich 10 bis 130 g Au/ml mit einem Fehler von ±0,5g. Thiocaprolactam bildet mit [AuCl₄]^– eine Verbindung im molaren Verhältnis TAuCl=112, mit [AuJ₄]^– im molaren Verhältnis TAuJ=213. Dagegen bilden sich im System T:Au:Br zwei verschiedene Verbindungen: Ein Bromidkomplex mit höherem Goldgehalt TAu=12, der mit Chloroform extrahierbar ist, und eine sich als Niederschlag ausscheidende Verbindung mit dem Verhältnis TAuBr=112.

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Thiolactams as reagents in quantitative analysis. IX

Summary Thiocaprolactam (T) is suitable for the determination of gold in the concentration range 10–130g Au/ml with an error of ±0.5g. Thiocaprolactam yields with [AuCl₄]^– a compound in the molar ratio TAuCl=112, with [Aul₄]^– in the molar ratio TAuI=213. On the other hand various compounds result in the system TAu Br. The molar ratio in the case of the bromide complex has a higher gold content, namely TAu=12; this product is extractable with chloroform and a compound that comes down as a precipitate shows the ratioT Au Br=112.

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Herrn Dr.K. Czerepko möchte ich hiermit meinen Dank für die Diskussion der Ergebnisse aussprechen.     

Spectrophotometric study of the reaction of Co(II) and Ni(II) with nitroso-R-salt and α-nitroso-β-naphthol

The complexes of Co(II) and Ni(II) with nitroso-R-salt are studied by conductometric titration and spectrophotometric methods in buffer solutions of differentpH. The study proved the possible formation of (11), (12) and (13) complexes for Co(II) while Ni(II) forms (11) and (12) complexes (metal:ligand) only. The factors affecting complex formation are established and the formation constants of the complexes are evaluated. The ir spectra of the solid complexes with -nitroso--naphthol revealed that the ligand exhibits the nitrosophenol structure and that the reaction takes place through proton displacement from the OH-group.

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Spektrophotometrische Studie zur Reaktion von Co(II) und Ni(II) mit Nitroso-R-Salz und -Nitroso--naphthol

Zusammenfassung Es wurden die Komplexe von Co(II) und Ni(II) mit Nitroso-R-Salz mittels konduktometrischer und spektrophotometrischer Methoden in Puffer-Lösungen mit verschiedenempH untersucht. Für Co(II) wurden (11)-, (12)- und (13)-Komplexe gefunden, während für Ni(II) lediglich (11)- und (12)-Komplexe (Metall:Ligand) festgestellt werden konnten. Die Faktoren, die die Komplexierung bestimmen, werden diskutiert und die Komplexbildungskonstanten wurden bestimmt. Die IR-Spektren der Komplexe mit -Nitroso--naphthol zeigen, daß der Ligand in der Nitrosophenol-Form vorliegt und daß die Reaktion über eine Protonenverschiebung von der OH-Gruppe verläuft.

     

Interactions of amphiphilic drugs withα-,β-, andγ-cyclodextrins

The association of several amphiphilic drugs with -, -, and -cyclodextrins has been measured by use of drug-sensitive electrodes. Drugs investigated are hydrochlorides of chlorpromazine, dibucaine, tetracaine, and procaine, and valethamate bromide. Each drug forms the drug:cyclodextrin=11 complex with - and -cyclodextrin, and both the 11 and 21 complex with -cyclodextrin, except valethamate which only forms the 11 complex. The strength of the 11 complex formations is in the order of CyD>-CyD>-CyD. The association constant of the 21 complex in drug--CyD is larger than that of 11 complex. The free energy change of the conplex formation has a positive correlation with that of the micelle formation of drugs. The deviation from this relation is explained in terms of fittability of the bulky hydrophobic group of drugs into the cyclodextrin's cavity. The free energy change for the complex formation between chlopromazine or valethamate and -CyD is governed by the enthalpy term and not by the entropy term which controls the surfactant--CyD interactions.     

Detection and determination of benzophenone present in diphenylhydantoin sodium formulations and drug substance

Summary The detection of benzophenone in sodium diphenylhydantoin formulations and drug substance is carried out by thin-layer chromatography on silica gel 60 F using toluene/methanol/ethyl acetate/acetic acid/chloroform (802015105) or ethyl acetate/methanol/ammonium hydroxide (85105) as solvent and UV-light for visualizing. The determination is performed by measuring the absorption at 248 nm. The method is recommended for production monitoring.

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Nachweis und Bestimmung von Benzophenon in Natriumdiphenylhydantoin-Formulierungen und -Reinsubstanz

Zusammenfassung Der Nachweis erfolgt dünnschicht-chromatographisch auf Silicagel 60 F mit Toluol/Methanol/Äthylacetat/Essigsäure/Chloroform (802015105) oder Äthylacetat/Methanol/Ammoniak (85105) als Lösungsmittel und durch Sichtbarmachung mit UV-Licht. Die Bestimmung wird durch Absorptionsmessung bei 248 nm vorgenommen. Das Verfahren wird zur Produktionskontrolle empfohlen.

     

A rapid chromatographic method for the estimation of thorium in rocks, soils and low grade ores

Summary A simple and rapid field Chromatographic method for the determination of thorium in ppm quantities in rocks, soils and low grade ores using paper strip chromatography is described. An aliquot of an hydrochloric acid solution of the sample is taken on a special paper (Chromatographic paper of C.R.L./l grade) and the paper is then placed into a beaker containing the solvent mixture consisting of methyl alcohol, acetone, 2-thenoyl trifluoroacetone and hydrochloric acid in the ratio 12 ml6 ml0.04 g2 ml (13) respectively.A saturated alcoholic solution of alizarin atph 2.8-2.4 is used as developing reagent.This method is applicable to samples containing from 0.2 ppm to 1000 ppm of thorium.

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Zusammenfassung Eine einfache und schnell durchführbare Feldmethode zur papierchromatographischen Bestimmung von ppm-Mengen Thorium in Gesteinen, Böden und Erzen niederen Gehaltes wird beschrieben. Hierbei wird ein Anteil der salzsauren Probelösung auf ein Spezialpapier (C.R.L./ 1 grade) aufgebracht und dieses in einem Becherglas mit einem Gemisch aus Methanol, Aceton, 2-Thenoxyltrifluoraceton und Salzsäure (12 ml 6 ml0,04 g2 ml [13]) chromatographiert. Zur Entwicklung dient eine gesättigte alkoholische Alizarinlösung (ph 2,8-2,4). 0,2–1000 ppm Thorium können nach diesen Verfahren bestimmt werden.

     

Thermal analysis of bitumens from black coal,extracted successively with different solvents

A successive extraction of bitumes from black coal was carried out using the following solvents: petroleum ether, petroleumether-benzene (11), benzene, benzene-ethyl ether (11), ethyl ether, ethyl ether ethanole (11), ethanol. These extract organic products as follows: 0.06, 0.16, 0.11, 0.21, 0.07, 0.29 and 0.70% respectively. The obtained by the above mentioned solvents chujniuds were compounds to the thermal and IR-spectral analysis.

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Zusammenfassung Mittels folgender Lösungsmittel wurde eine sukzessive Extraktion von Bitumen aus Steinkohle durchgeführt: Petrolether, Petrolether-Benzol (11), Benzol, Benzol-Ethylether (11), Ethylether, Ethylether-Ethanol (11), Ethanol. In dieser Reihenfolge konnten organische Produkte zu 0.06, 0.16, 0.11, 0.21, 0.07, 0.29 bzw. 0.70 % extrahiert werden. Die durch aufgeführte Lösungsmittel erhaltenen Verbindungen wurden einer Thermound einer IR-Analyse unterzogen.

     

Beitr?ge zur Thermostabilit?t und zur Bestimmung des Feuchtigkeitsgehaltes von Vitamin B12-Pr?paraten

Zusammenfassung Die Flüssig-flüssig-Extraktion des Goldes als Polyäthylenglykoloxonium-saccharino-aurat(III) erlaubt seine Trennung von Palladium, Platin, Arsen, Antimon, Mangan, Nickel, Eisen, Kobalt und anderen Metallen bis zu den Verhältnissen AuPdPtAsMnSbNiFeCo =110060070010001500100002000050000. Trennungen Au/Pb sind beim Verhältnis 150000 mit der photometrischen Meßgenauigkeit durchführbar. Das Gold wird in der nichtwäßrigen Phase bei 315 nm photometrisch bestimmt.Teil II: Ziegler, M., u. H.-D. Matschke: diese Z. 184, 166 (1961).     

Separation of strontium from calcium by means of anion exchanger and alcoholic solution of nitric acid

A possibility of mutual separation of calcium and strontium on an anion-exchange column has been studied and then used in working out methods of separation of radioactive strontium from natural samples. All examinations, carried out on model systems, showed that calcium could be completely separated from strontium on the column with the anion exchanger Amberlite CG-400 using 0.25M HNO₃ in methanol as eluent. The flow velocity of this eluent in the range between 1 ml/min and 5 ml/min did not influence the efficiency of separation of calcium from strontium. The increase of the concentration of nitric acid in methanol reduced the efficiency of their mutual separation and the increase of exchanger column height neutralized the influence of the increase of acid concentration. Calcium was separated from strontium in the mass concentration ratio (Ca²⁺)/(Sr²⁺) in the range between 11 to 1001. This separation procedure may be used for the isolation of radioactive strontium from real samples instead of using fuming nitric acid.     

Determination ofFe 2+ content of NiZnCo iron-excess ferrites by thermogravimetry

Experimental results are reported on the determination by thermogravimetry of the iron(II) content of the NiZnCo ferrite with the molar ratio Fe₂O₃NiOZnOCoO=59.019.520.51.0.     

Complexes of metallochromic substances. VI

Summary Two new simple spectrophotometric methods are developed, which are based on the estimation of one or two pairs of absorptivities in given conditions. The first extrapolation method is convenient for the determination of formation constants of complexes 11, 21, and 22 (LM). The second calculating method is suitable for the classification of complexes 11 and 22.

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Zusammenfassung Zwei neue, einfache spektralphotometrische Methoden wurden entwickelt, die auf der Bestimmung von einem oder zwei Extinktionspaaren unter gegebenen Bedingungen beruhen. Die erste Extrapolationsmethode ist für die Bestimmung der Bildungskonstanten von Komplexen 11, 21 und 22 (LM) geeignet. Die zweite Rechnungsmethode eignet sich für die Klassifikation der Komplexe 11 und 22.

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Part V, see: Z. analyt. Chem. 207, 247 (1965).     

N,N,N′,N′-tetrabutylsuccinylamide as a new extractant in n-dodecane for extraction of uranium(VI) and thorium(IV) ions

N,N,N,N-tetrabutylsuccinylamide (TBSA) was synthesized, characterised and used for the extraction of U(VI) and Th(IV) from nitric acid solutions into n-dodecane. Extraction distribution coefficients of U(VI) and Th(IV) as a function of aqueous nitric acid concentration, extractant concentration and temperature have been measured and found that n-dodecane as diluent was superior to 50% 1,2,4-trimethyl benzene (TMB) and 50% kerosene, (OK) system for extraction of U(VI) and Th(IV). The compositions of extracted species, equilibrium constants and enthalpies of extraction reactions have also been calculated. The formation of the 121 complex of uranyl(II) ion or the 141 complex of thorium(IV) ion, nitrate ion and TBSA and extracted species was further confirmed by the IR spectra of saturated extract of U(IV) and Th(IV).     

Some effective solvents for rapid and reliable characterization of phenylthiohydantoin-amino acids

Summary One-dimensional chromatography with internal standards permits reliable identification of the phenylthiohydantoins from all the common amino acids with the following TLC systems: silica gel — chloroform/n-butyl acetate (9010), di-isopropylether/ethanol (955), dichloromethane/ethanol/acetic acid (9082) ortrans-dichloroethylene/ethanol/acetic acid (88102); and cellulose with 25% formic acid — heptane/isobutanol/75% fromic acid (40309) or silica gel — chloroform/ ethanol/acetic acid/water (50470.52.5).Abbreviations: PTH=phenylthiohydantoin, TLC=thin-layer chromatography, HPTLC=high-performance TLC; other abbreviations: see end of text. Proportions in solvent mixtures are v/v except where otherwise indicated.     

Eine empfindliche Methode zur Bestimmung von Beryllium mit Chromazurol-S und 2,2′-Bipyridyl

Zusammenfassung Eine spektralphotometrische Methode zur Bestimmung von Mikrogrammengen Beryllium mittels Chromazurol-S in Anwesenheit von 2,2-Bipyridyl wurde beschrieben. Letzteres steigert die Empfindlichkeit der Methode wesentlich; _=610nm beträgt 5,4 × 10⁴. Die Komplexverbindung gehorcht dem Lambert-Beerschen Gesetz im Konzentrationsbereich von 0,002 bis 0,2 ppm Be. Die maximale Farbintensität wird bei pH 5 sofort erreicht. Das molare Verhältnis BeCHASBip beträgt 121. Die vorgeschlagene Methode ist empfindlich und bei Anwendung von ÄDTA als Maskierungsmittel befriedigend selektiv.

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A sensitive method for assay of beryllium with chromazurol S and 2,2-bipyridyl

Summary A spectrophotometric method of assay for microgram amounts of beryllium by means of chromazurol S in presence of 2,2-bipyridyl was described. The latter appreciably enhances the sensitivity of the method; _=610nm is 5.4 × 10⁴. The complex compound obeys the Lambert-Beer law in the concentration range 0.002 to 0.2 ppm Be. The maximum color intensity is immediately attained at pH 5. The molar ratio BeCHASbip is 121. The suggested method is sensitive and has satisfactory selectivity when EDTA is applied as masking agent.

     

Phosphorus-containing podands. 6. Calorimetric study of complexation of 1,17-bis (diphenylphosphinyl)-3,6,9,12,15-pentaoxaheptadecane with alkali and alkaline-earth metal salts in acetonitrile

1, 17-bis-(Diphenylphosphinyl-3, 6, 9, 12, 15-pentaoxaheptadecane in MeCN forms complexes of 11 and 12 composition (ML) with alkali and alkaline-earth metal salts, complexes of 11 and 21 composition were found for Li salts. The BaL²⁺ complex is the most stable complex, and the complexes NH₄L⁺ and CaL2+ are the least stable. The selectivity for Li is significantly higher for the podand studied than for crown ethers.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 575–581, March, 1991.     

Solvent extraction and spectrophotometric including graphite furnace atomic absorption determination of molybdenum in the environment

A selective and sensitive method for the extraction and microgram determination of molybdenum (VI) with hydroxamic acid as yellow molybdenum-hydroxamate complex from acidic medium is described. The molybdenum-PCPPSAHA complex has _max 388 nm, molar absorptivity 5.0 × 10³l mol^–1 cm^–1. The system obeys Beer's law in the range of 1–28 g/ml of molybdenum(VI). Sandell's sensitivity is 0.0192 g cm² and stoichiometry of the complex is 12, molybdenum: PCPPSAHA while mixed complex molybdenum-PCPPSAHA-morin has _max 400 nm and molar absorptivity 5.9 × 10³lmo1^–1 cm^–1 and stoichiometry of the complex is 121.The molybdenum is determined by graphite furnace atomic absorption spectrophotometry after directly pipetted the extract into the furnace which increases the sensitivity 20 fold.     

Effect of alkali ions (Na+, K+) on the solvent extraction of uranium(VI) with a di-carboxylated calix[4] arene

The solvent extraction of uranium(VI) with a di-carboxylated calix[4]arne (LH₂) in chloroform and 1,2-dichloroethane has been studied in the presence or absence of alkali ions (M=Na⁺,K⁺). For UO ₂ ²⁺ when studied alone, a 12 (metal: ligand) extracted species is evidenced, with a rather low associated extraction equilibrium constant. The efficiency of extraction increases drastically in the presence of alkali ions, due to the formation of heteronuclear complexes. In all cases, the extracted species are found to be both 122 and 112 (UO ₂ ²⁺ MLH₂) mixed complexes, except in chloroform with K⁺, where only the latter is formed. In the case of Na⁺, mass spectrometry spectra confirm the existence of both homo and heteronuclear complexes as determined in the extraction studies.     

Interaction between carbon dioxide and magnesium oxide prepared by low-temperature thermal decomposition of magnesium hydroxide and carbonate

The interaction of CO₂ with MgO has been studied. The reaction mechanism is discussed with special attention to the important catalytic role of the surface hydroxy groups of the active oxide.

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CO₂ MgO. , .

     

Determination of ten anti-inflammatory drugs in serum by isocratic liquid chromatography

Summary A high performance liquid chromatographic system has been developed for the resolution of ten anti-inflammatory drugs. Isocratic separation was achieved using a Spherisorb 5m ODS column with an eluent consisting of water-orthophosphoric acid to pH 3.2: acetonitrile: methanol (523513). A comparison was made between chloroform/acetonitrile (32) and hexane/ether (11) as solvents for the extraction of these drugs from serum.