Sur la thermogravimétrie des précipités analytiques : Dosage du Lithium

The four salts normally used for the gravimetric determination of lithium have been submitted to pyrolysis with the aid of the chevenard thermobalance. To obtain correct results it is necessary to heat the chloride between 175° C, and 606° C, the sulphate above 160°, the phosphate above 450° C, and the aluminate above 471°.     

Sur la thermogravimétrie des précipités analytiques : Dosage du néodyme

In the gravimetric determination of neodymium, the hydroxide should be heated to above 608° and the oxalate decahydrate to above 813°, in order to ensure a correct weight. The anhydrous oxalate can be weighed after heating between 290° and 350°.     

Sur la thermogravimétrie des précipités analytiques: Dosage du lanthane

The three gravimetric methods so far proposed for the determination of lanthanum have been tried out experimentally. The oxide prepared from the hydroxide must be heated to at least 944° and that obtained from the oxalate at not less than 876°. The basic carbonate reaches almost constant weight between 700° and 800°. Finally the oxinate should be kept at 130°.     

Étude de réactions à l'état solide entre l'arbre de Saturne et des sels contenant le groupement XO3

Résumé Le plomb utilisé sous forme d'arbre de Saturne possède une grande réactivité et permet de réduire les nitrates en nitrites. Il s'agit d'une réaction à l'état solide, débutant dès la température ordinaire. On a pu caractériser ainsi la présence de nitrites en mélangeant le plomb avec les nitrates de lithium, sodium, potassium, césium, cuivre, argent, magnésium, calcium, strontium, baryum, zinc, thallium, plomb, cobalt et nickel.

---

Summary Lead used in the form of the lead tree has great reactivity and is able to reduce nitrates to nitrites. This involves a solid state reaction and starts at room temperature. In this way it is possible to detect the presence of nitrites after mixing the lead with the following nitrates — Li, Na, K, Cs, Cu, Ag, Mg, Ca, Sr, Ba, Zn, Tl, Pb, Co, Ni.

---

Zusammenfassung In der Form des Bleibaumes ist Pb sehr reaktionsfähig und reduziert Nitrat zu Nitrit. Dabei handelt es sich um eine Festkörperreaktion, die bei gewöhnlicher Temperatur einsetzt. Nach Vermengen von Blei mit den Nitraten von Li, Na, K, Cs, Cu, Ag, Mg, Ca, Sr, Ba, Zn, Th, Pb, Co und Ni konnte die Anwesenheit von Nitrit festgestellt werden.

---

---

En l'honneur du ProfesseurA. A. Benedetti-Pichler, pour son 70^e anniversaire.     

Determination of free carrier protein in protein-polysaccharide conjugate vaccines by micellar electrokinetic chromatography

Protein-polysaccharide conjugate vaccines offer the prospect of reducing morbidity and mortality due to bacterial pneumonia and meningitis but, because of their size and heterogeneity, are often a challenge to characterize by traditional analytical methods. Vaccines consisting of Streptococcus pneumoniae, or Neisseria meningiditis polysaccharide covalently linked to formaldehyde-inactivated diphtheria toxoid carrier protein were resolved from non-conjugated toxoid by micellar electrokinetic chromatography. Separation was achieved using alkaline sodium borate solutions containing sodium dodecyl sulfate in excess of the critical micellar concentration. No sample pretreatment was required prior to analysis. Diphtheria toxoid peak migration times were highly reproducible. Measurement of absolute toxoid peak area showed poor precision, but good precision was observed when peak area was normalized against an internal standard (myoglobin). Good linearity was observed over useful ranges of both protein content and injection time.     

Detection of stable isotopes with A (n, α) nuclear reaction: Application to the measurement of unidirectional fluxes of borate in a plant

The unidirectional influx of borate has been studied inLemna minor plants with the aid of purified boron isotopes,¹⁰B and¹¹B. Isotope¹⁰B was detected specifically by nuclear reaction¹⁰B(n, α)⁷Li in the presence of “homogeneous” detectors. Despite technical difficulties in performing the¹⁰B-estimations in the plant samples themselves, the results obtained here were consistent with those of efflux experiments, published previously, where the¹⁰B-measurements were performed in the external solution. Kinetic parameters of borate transports inLemna minor have been calculated.     

Etude des acides aminés sur une goutte de solution aqueuse par spectrographie infrarouge

Résumé L'auteur donne les spectres infrarouges des solutions neutres, acides et basiques d'un certain nombre d'amino-acides; il fournit les bandesclés utiles pour un futur dosage et examine l'influence de l'alanine et de l'acide glutamique quand on les mélange au glycocolle.

---

Summary The infra red spectra of neutral, acid, and basic solutions of a certain number of amino, acids are given. The author also provides the key bands to be used for a future determination. He examines the influence of alanine and glutamic acid when they are mixed with glycine.

---

Zusammenfassung Die Infrarotspektren neutraler, saurer und basischer Lösungen einer Reihe von Aminosäuren werden angegeben. Die für die künftige Bestimmung geeigneten Schlüsselbanden wurden festgestellt und der Einfluß von Alanin und Glutaminsäure in Mischungen mit Glykokoll untersucht.

---

---

A M. le Professeur de l'Université Dr.Hans Lieb à l'occasion de son 70ème anniversaire.     

Synthesis and structural characterization of a uranyl(VI) complex possessing unsupported unidentate thiolate ligands

The synthesis and structural characterization of the first example of a uranyl(VI) complex possessing unsupported unidentate thiolate ligands, UO2(S-2,6-Cl2C6H3)2L2 (2b, L=N,N-diisobutylisopropylamide), are reported. Isolation of 2b as a stable mononuclear complex is provided by the alkyl substituents of the organic amide ligands, which offer enhanced solubility, electron-releasing properties, and steric protection to help saturate the uranyl(VI) coordination sphere.     

Synthesis and Diels-Alder Reactions of a New Kind of Chiral Dienophiles: Cyclic Vinyl-p-tolylsulfilimines

A new kind of chiral dienophiles, cyclic vinyl-p-tolylsulfilimines (2a and 2b), were obtained from the corresponding (Z)-sulfinylacrylonitriles with HBF(4) and methanol. The asymmetric Diels-Alder reaction of optically pure 2a with cyclopentadiene under mild thermal or catalyzed conditions afforded only the endo-4a adduct with complete endo and pi-facial selectivities. The ability of the sulfilimine moiety to enhance the dienophilic reactivity of the double bond is similar to that of the sulfinyl group.     

Sur la thermogravimétrie des précipités analytiques : Dosage de L'ammonium

The temperature of 110° C is quite suitable for drying ammonium chloride, prior to weighing. If the residual platinum from the pyrolysis of ammonium chloroplatinate is weighed it. is necessary to ignite, either between 407° and 538° C, or above 811° C.