Gas chromatography ofγ-valerolactam andγ-valerolactone from reductive amination of butyl levulinate

Summary The-valerolactam and-valerolactone in the reductive amination products of butyl levulinate in water or alcoholic medium, after removing most of the light fractions, ammonia, and water or alcohol, have been determined by isothermal gas chromatography using phenylether or isoamyl salicylate as the internal standard. With the thermal conductivity detector, a column of 6 mm I. D., 2 m long copper tubing packed with 25% glycol adipate/chromosorb-W was used, with hydrogen as the carrier gas. The accuracy was ± 0.4% for-valerolactone and ± 0.5% for-valerolactam. Using the hydrogen flame ionization detector, a column of 3 mm I. D., 2 m long stainless steel tubing packed with 10% glycol adipate/chromosorb-W was used, with nitrogen as the carrier gas; the accuracies for-valerolactone and-valerolactam were ± 0.5% and ± 0.8% respectively.

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Zusammenfassung Unterwirft man Butyllävulinat in wäßrigem oder alkoholischem Milieu der reduktiven Aminierung, so entstehen unter anderem-Valerolactam und-Valerolacton. Diese wurden nach weitgehender Entfernung der flüchtigen Anteile (Ammoniak, Wasser oder Alkohol) durch isotherme Gaschromatographie unter Verwendung von Phenyläther oder Isoamylsalicylat als interne Standards bestimmt. Mit einem Wärmeleitfähigkeitsdetektor wurde eine 2 m lange Säule mit 6 mm i. D. aus Kupferrohr mit einer Füllung aus 25% Glykoladipat und Chromosorb W verwendet, mit Wasserstoff als Trägergas. Die Genauigkeit betrug ± 0,4% für-Valerolacton und ± 0,5% für-Valerolactam. Wurde hingegen ein Ionisierungsdetektor mit Wasserstoff-Flamme verwendet, so diente eine 2 m lange Säule mit 3 mm i. D. aus rostfreiem Stahl mit einer Füllung aus 10% Glykoladipat und Chromosorb W und Stickstoff als Trägergas. Die Genauigkeit betrug dann ± 0,5 bzw. ± 1,8%.

     

Detection of vanadium by means of spot tests

Zusammenfassung Zwei neue Tüpfelreaktionen für Vanadinum werden beschrieben.-Benzoinoxim gibt einen gelben Niederschlag in schwefelsauren Vanadatlösungen, der auf der Tüpfelplatte den Nachweis von 1 Vanadinum ermöglicht. Der Nachweis der durch Zusatz von Vanadylsalz zu Ferrichlorid gebildeten Ferroionen kann auf der Tüpfelplatte mit,-Dipyridyl oder mit o-Phenanthrolin durchgeführt werden. In beiden Fällen wird eine Erfassungsgrenze von 0,1 Vanadinum erreicht und nur wenige Ionen stören den Nachweis.Der Nachweis der Ferroionen mit Hilfe von Dimethylglyoxim (1 V) und auch der Vanadatnachweis durch die durch Wolframat erzeugte Gelbfärbung (0,3 V) wurden in bezug auf Störungen durch gleichzeitig anwesende Stoffe gründlich untersucht. Die Dimethylglyoximprobe wird durch Zusatz von Phosphat wesentlich verbessert.

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Résumé Deux nouvelles réactions à la touche sont décrites pour le vanadium. L'-benzoinoxime donne un précipité jaune en solution sulfurique de vanadate qui, sur la plaquette à touche, rend possible la recherche de 1 vanadium. La recherche des ions ferreux formés par addition d'un sel de vanadyle au chlorure ferrique peut être conduite sur plaquette avec l', -dipyridyle ou l'o-phénanthroline. Dans les deux cas, on atteint une limite de sensibilité de 0,1 de vanadium et quelques ions seulement gênent la recherche.Celle des ions ferreux au moyen de la diméthylglyoxime (1 de vanadium) et aussi la recherche des vanadates par la coloration jaune donnée avec un tungstate (0,3 de vanadium) furent expérimentées d'une manière approfondie en fonction des interférences par les substances simultanément présentes. L'essai à la diméthylglyoxime est essentiellement amélioré par addition de phosphate.

     

Development and application of parallel-plate avalanche counter for in-beam Mössbauer spectroscopy

For Mössbauer -rays in the in-beam Mössbauer experiments using various beams such as heavy ion, secondary short-lived isotope, and neutron beams, it is important to develop a detector. A parallel-plate avalanche counter (PPAC) is the most suitable gas counter for on-line measurements, because PPAC collects the internal conversion electrons emitted by the Mössbauer effect even under high -background. We evaluated the influences of the pressure and flow rate of the counter gas against the counting efficiency of PPAC, and determined the optimum conditions for use in the in-beam Mössbauer experiments.     

Sol-Gel Synthesis and Gas Adsorption Properties of CuCl Modified Mesoporous Alumina

Cuprous chloride (CuCl) modified unsupported -alumina membranes and adsorbent granules were synthesized by sol-gel processing followed by wet-impregnation of CuCl. The CuCl coated -alumina remains mesoporous with a uniform pore size distribution and a large surface area. The mesoporous alumina granules, prepared by a sol-gel oil-drop process, exhibit excellent mechanical strength and attrition resistance. The CuCl modified -alumina preferentially adsorbs ethylene and carbon monoxide, with a saturated adsorption capacity of 0.67 and 0.78 mmol/g, respectively. Both equilibrium capacity and kinetic rate for adsorption of ethylene and carbon monoxide on the CuCl modified -alumina are much larger than those for ethane and carbon dioxide. These results indicate the potential use of the sol-gel derived CuCl modified -alumina for separation of ethylene or carbon monoxide from its gas mixture containing ethane or carbon dioxide.     

Compton suppression neutron activation analysis: Past,present and future

Conclusions In this work a review of the development of compton suppression is presented. It was shown that the application of Compton-suppression counting in instrumental NAA reduces the detection limits and improves the accuracy for a list of elements by substantial reduction of the background of the -spectroscopy. Results for certified reference materials obtained through the use of Compton suppression are normally more accurate and in agreement with the published values. Compton suppression is particularly helpful for low level concentrations in environmental samples to those elements which exhibit severe special interferences in the normal NAA counting. A list of the elements with isotopes having single or close to single -ray decay schemes and which could benefit from Compton-suppression counting is presented. Also, evaluation is made regarding the reliability of Compton suppression with increase in the overall dead-time of the counting. It was concluded that this method does not provide accurate quantification of the isotopes when the overall dead-time exceeds the 10% range. Investigation of the natural background was performed with Compton suppression for the purpose of neutron activation analysis application. The method presented proves to broaden the application of NAA and helps in its competition for simplicity, accuracy and reliability with the modern methods of elemental analysis. Future application of coincidence spectrometry in activation analysis should include better enclosing of the primary detector, utiliza5tion of x-ray and well type detectors, -, -, and -- coincidence techniques.     

An empirical equation-of-state for solid-fluid interfacial free energies

The contact angle,, formed by a liquid on a solid surface in air depends on the solid-air ( _S ), liquid-air ( _L ) and solid-liquid ( _SL ) interfacial free energies, as described by Young's equation. Critical examination of reported contact angles for numerous liquids and solids leads to an empirical correlation between _sL and both _Y and _S . Combination of this correlation with Young's equation gives an empirical relation allowing calculation of _S from _L and Calculations made with these empirical relations agree well with estimations of _S obtained by the method of critical spreading, and are consistent with Young's equation.Founded and supported by F. Hoffmann-La Roche and Co., Limited Company, Basel, Switzerland.     

A new gamma-ray spectrum catalog and library for PGAA

New measurements have been performed at the PGAA facility at the Budapest Research Reactor (BRR) in order to create a prompt -ray catalog for qualitative and quantitative analysis. The measured spectra were accurately analyzed by HYPERMET-PC. Prompt -ray energies and associated -ray production cross-sections have been determined by internal standardization. The resulting catalog contains prompt -ray data from neutron capture and other reactions such as (n,), and decay -ray data from short-lived reaction products. Data have been measured for nearly all stable elements, from hydrogen to uranium. Generally, data for several isotopes are given, to enable isotopic analysis as well. The whole library, including elemental spectra, will be available as a book.     

Multiparameter coincidence spectromety applied to the instrumental activation analysis of rocks and minerals

An instrumental method for activation analysis based on multiparameter coincidence spectrometry is described. Practical considerations of our X- and - coincidence systems are presented. The main applications of geochemical interest are the non-destructive determinations of tin in granitic rocks and iridium in ultra-basic rocks. Some other applications to the activation analysis are proposed.     

Radiometric measurements of fallout under accidental conditions

Empirical expression for experimentally obtained functional dependence between the results of total -activity and integral -activity activity of fallout, measured during May, 1986, at a control point: 44°47 northern latitude and 20°32 eastern longitude, has been established in order to enable estimation of the level of fallout contamination by -emitters when total -activity values are known.     

Synthesis of mono- and dilactones from 2,7-disubstituted 4-octene-1,8-dioic acids

2,7-Disubstituted 4-octene-1,8-dioic acids are formed by heating the-lactones of 2,7-disubstituted 4-hydroxyoctane-1,8-dioic acids to 250°C. The bromination of these unsaturated dicarboxylic acids gives,-dilactones of 2,7-disubstituted 4,5-dihydroxyoctane-1,8-dioic acids.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1590–1592, December, 1971.     

High precision determination of uranium in ore by gamma-ray spectrometry

A new approach for the determination of elemental uranium in uranium bearing ore, using high resolution -ray spectrometry, was applied. Using a variant of the enrichment technique an agreement of better than 1% has been obtained between -ray measurement results and a certified value obtained by other analytical methods. For the calibration of the -ray spectrometer uranium reference samples have been used which are made available jointly in Europe and the USA as Certified Reference Materials for Gamma-Ray Spectrometry (EC NRM 171 and NBS SRM 969, respectively). The measured ore has been put in a special designed container which ensured in all directions seen from the radiation window an uniform degree of infinite thickness of about 95%. The results can be taken as an example for the applicability of -ray spectrometry when high accuracy is required and under conditions were homogeneously distributed elemental uranium is embedded in larger amount of matrix material.     

Complexation of Calix[4]arenephosphonous Acids with 2,4-Dichlorophenoxyacetic Acid and Atrazine in Water

In capillary electrophoresis using poly(vinyl sulfate), added to sample solutionsand running buffers, the signal of Rhoda-mine 6G (R6G) is shaped like a squarewave. When -, -, or -cyclodextrin (-, -,or -CD) has further been added to the running buffers as well as samplesolutions, the intensity of the square-wave type signal of R6G has been enhanced,accompanied by narrowing of the signal width. The migration time of the risingedge of the square-wave type signal has been very slightly delayed by the additionof CD. These findings exhibit the formation of inclusion complexes of R6G withCDs. From the analyses of the variations in signal width with the concentration ofCD, the equilibrium constants for the formation of the 1:1 inclusion complexes ofR6G with -, -, and -CDs have been evaluated to be 245,210, and 302 M^-1, respectively, although the equilibrium constants could not be estimated using a conventional procedure based on electrophoretic mobility, inwhich poly(vinyl sulfate) was not added. The values of the equilibrium constants for- and -CDs are comparable to those obtained from the absorbancechanges in spectrophotometry, whereas the value for -CD is about four timesgreater than that obtained from the absorbance change.     

EPR in strongly irradiated polyacetylene

The influence of -irradiation on the paramagnetic properties of polyacetylene has been studied. The samples were exposed to -irradiation up to a dose of 3 MGy.     

Circular dichroism spectra of the inclusion complexes of phlorizin in cyclodextrins

Two aromatic rings of a phlorizin molecule form inclusion complexes with -CD and -CD. Induced circular dichroism spectra of these complexes have been measured to estimate the orientation of the two aromatic rings in the hydrophobic space of CDs. Apparent complex formation constants have been also estimated for each complex. It is concluded that phlorizin forms a stronger inclusion complex with -CD than with -CD.     

Radiopapierchromatographie der Isomeren des 1.2.3.4.5.6-Hexachlor-cyclohexans (HCH)

Zusammenfassung Für die quantitative Auswertung der Aktivitätsverteilung auf Radiopapierchromatogrammen wurde ein 4-Durchnußzähler gebaut. Der Aufbau und die Betriebsweise dieses Zählers werden beschrieben. Die Anwendung der Radiopapierchromatographie als quantitative Analysenmethode wird am Beispiel des Isomerisierungsgleichgewichtes -HCH -HCH -HCH erläutert.Der Vereinigung von Freunden der Technischen Hochschule Darmstadt und dem Fonds der Chemischen Industrie danken wir für finanzielle Unterstützung.     

Distribution of137Cs,40K,238U and232Th in soils from Northern Venezuela

More than one hundred undisturbed soil samples from Northern Venezuela and the islands of Margarita and Los Roques have been analyzed for¹³⁷Cs,⁴⁰K,²³⁸U and²³²Th by -ray spectroscopy. The specimens were taken from between 5–10 cm below the earth's surface. Thus, they are valid not only for the¹³⁷Cs deposition studies but also for the estimation of the natural -ray dose from primordial radionuclides that form the terrestrial component. The concentration of⁴⁰K was directly determined from its 1461 keV -ray, while those of¹³⁷Cs,²³⁸U and²³²Th were performed using a -ray from one of their daughter radionuclides: the 661 keV -ray of^137mBa for¹³⁷Cs, the 1760 keV -ray of²¹⁴Bi for²³⁸U and the 2620 keV -ray of²⁰⁸Tl for²³²Th. Finally, the concentration values were compared with those of global estimates.     

Adsorption behavior of polymers having phosphoric acid group on γ-Fe2O3 and magnetic characteristics in magnetic coatings

Polymers having phosphoric acid groups were prepared as a model binder for magnetic coatings, and the correlation among the adsorption behavior of the polymers onto-Fe₂O₃ particles and the dispersibility, the orientation, and the packing density of-Fe₂O₃ particles in the magnetic coatings was investigated.PMMA homopolymer molecules hardly adsorbed on-Fe₂O₃, and the interfacial tension at a water/polymer solution (toluene) interface ( _W/T) was scarcely changed compared with a water/toluene interface. Increasing with the content of polymeric phosphoric acid group, the adsorbance of polymer increased and the interfacial tension ( _W/T) decreased. When the content of polymeric phosphoric acid groups was over 0.4 mol%, the adsorbance of polymer and interfacial tension ( _W/T ) remained constant. When these polymers were used as a binder for magnetic tapes, the dispersibility of-Fe₂O₃ in the magnetic coatings was improved, increasing with the content of polymeric phosphoric acid group; however, when the content of phosphoric acid group was over 0.2 mol%, its dispersibility decreased abruptly.Studies on Recording Magnetic Materials and Magnetic Composite. XVIII.