Showing papers in "Analytica Chimica Acta in 1948"

TL;DR: In this article, the authors describe diaminobenzidine as a reagent for V + 5 and show that it behaves similarly to benzidine in this respect, but is more specific and is interfered with by the presence of oxidizing constituents.

TL;DR: In this article, a potentiostat is described which automatically maintains the potential of a working electrode constant during an electrolysis, and some typical applications are reviewed, including electrogravimetric determinations of metals, electrolytic separation of metals with mercury and platinum cathodes, coulometric analysis, identification of the oxidation states that correspond to polarographic waves, and electrolytic preparation of organic and inorganic compounds.

TL;DR: Germanium is quantitatively precipitated by tannin from oxalate solution at 007 N acidity, the white precipitate settles quickly, and is easily filtered and washed Clean separations are effected in one precipitation from vanadium, ferric iron, and elements of Tannin Group B Germanium is shown to be a member of Group A, being precipitated at an acidity below that required for tin and tantalum but above the required for titanium Davies and Morgan's precipitation procedure in acid sulphate solution was tested as mentioned in this paper.

TL;DR: In this article, the selecting principles for gas mixtures and those for liquid mixtures, according to the "cage-model" are mentioned, and experiments with synthetic mixtures of liquid hydrocarbons generally confirmed these principles.

TL;DR: In this article, a description of some microbiological assays for the estimation of copper, magnesium, and molybdenum in soils as well as in plant tissues is given.

TL;DR: In this paper, a critical study of the colorimetric determination of magnesium with titan yellow was conducted and it was concluded that titan yellow must be present in excess; a mixture of glycerol and starch solution is satisfactory as protecting colloid.

TL;DR: In this paper, a new chromatographic separation of antimony was proposed, where Sb+3 can be separated from all common metallic ions by absorbing one drop of the solution to be tested on a strip of filter paper on which Sb +3 is strongly absorbed and after development with H 2 O shows up very close to the spot when the strip is held over H 2 S vapours.

TL;DR: In this paper, the CO2 is absorbed in barium hydroxide, the excess of which is determined by titration with 0.1 n hydrochloric acid on cresolphthalein as the indicator.

TL;DR: In this article, an optimal culture solution was developed for the determination of potassium and phosphate by means of Aspergillus niger, which was sufficiently buffered to keep the PH changes between allowable limits, which was not influenced by the humus-content of the soil, nor by the presence of calcium and sodium salts.

TL;DR: In this paper, the authors present la premiere au dosage des traces d'iodates dans les periodates et inversement; elle permet de plus d'adapter au polarographe, de facon rapide et sensible, la micromethode de dosage du potassium de willard et boyle.

TL;DR: In this article, the authors decrit un procesence de titrage direct des ions cereux par le permanganate en milieu sensiblement neutre en presence d'ions pyrophosphoriques.

TL;DR: In this article, a number of Verfalnen wurden auf die Tatsache gegrundet, dass das Jodidion durch freies Chlor zu Jodat oxydiert and der Uberschuss an Chlor durch KCN, als CICN, das jodid nicht oxydiet, gebunden werden kann.

TL;DR: In this article, a methode de dosage des traces dc gallium dans les bauxites et procluits derives is presented, which permits de doser 1.4 4.2 γ de gallium, a 10% pres.

TL;DR: In this paper, a colorimetric method for the determination of thorium is proposed, based upon the precipitation of the thorium with a standard solution of oxalic acid and the subsequent reaction of the excess oxalinic acid with a normal solution of potassium permanganate.

TL;DR: In this paper, auteurs ont prepared 67 precipites, i.e., gravimetriques, for effectuer le dosage gravimetrique du cuivre, and le thermobalance de Chevenard a permis de determiner les temperatures auxquelles il faut les porter pour obtenir un poids correct.

TL;DR: In this paper, Chevenard et al. present deux trioxydes presente deux domaines thermiques d'exibtence, le trioxyde prepare elcctrolytiquement: 156° a 283°; chlorure: 56° a 425°; iodure: 70° a 473°; sulfate: 92° a 355°; thallichlorure luteocobaltique; and chromat: 50° a 210°; chromate: 97° a 745°.

TL;DR: In this article, with the aid of the Spckkei absorptiometer the colonmetnc delerminations, of nickel (with dimethylglyoxime), chromium (with diphenylcarbazide) and manganese (after oxidation with periodate) in steel were critically evaluated.

TL;DR: In this paper, the perte de poids de papiers-filtres dits “sans cendres” is described, and the result is reproductible, ne dependent pas de la grosseur des pores et s'etendent meme, mot pour mot, au coton hydrophile.

TL;DR: In acid and fluoride-ion-containing solutions all precipitation and colour-reactions of MoO 4 "and WO 4 ''-ions and the greater part of VO 3 ''-ion reactions do not occur.

TL;DR: In this article, the value of micro-melting point measurements was investigated using three groups of closely related substances (benzoic acid derivatives, barbituric acid derivative, and sulphonamids).

TL;DR: In this paper, a method for sugar analysis was developed, which enables us to determine all sugars in foods by reductometric and biochemical methods, and the results of these analyses were worked up by mathematical methods.

TL;DR: In this article, the authors considered the problems relating to the indirect determination of the water content on the basis of absolute water vapour pressures and indicated the advantages and disadvantages of this method of treatment.

TL;DR: In this paper, a breve revue montre que les spectres d'absorption infrarouges sont capables de fournir des renseignations.

TL;DR: The methode de Ball, rnoins classique que les autres, meriterait une plus grand attention de la part des analystes as discussed by the authors, s'est surtout portee sur les acetates triples que nous conseillons de peser seulement a 1'etat de pyro-uranates.

TL;DR: In this paper, les auteurs etudient la pyrolyse des compos'es suivants de magnesium qui ont ete proposes pour le dosage gravimetrique de cet e1ement: hydroxyde, fluorure, sulfate, phosphate ammoniaco-magnesien, arseniate ammoniac o-magne sien, carbonate ammoniacoencogenien, oxalate and hydroxy-8 quinoleate.

TL;DR: In this article, the pyrolyse de 10 composes du potassium and fixe les limites entre lesquelles il faut secher pour pouvoir les peser avec certitude.

TL;DR: In this paper, the extinction coefficient of dilute solutions is calculated as a function of the iodine concentration for temperatures ranging from 10 to 30° C. The extinction coefficient can be used to determine oxygen in water in concentrations ranging from 0.005 to 0.4 mg O2/litre.

TL;DR: In this paper, the water content of potato starch with the aid of P 2 O 5 in vacuo at 75°C was determined using the PREGL method and its exactness and accuracy were verified with BaCl 2.2H 2 O as reference substance.

TL;DR: A survey of the application of chromatograpinc analysis to mixtures of hydrocarbons has been given in this paper, where an empirical constant called "transport factor" has been introduced.