A. A. Benedetti-Pichler

Gravimetric microanalysis of beryllium silicate rocks

The micro determination of P2O5, Al, Fe, Be, and Mg have been investigated to determine their applicability to a system of separation. In the case of magnesium and beryllium new methods of determination were worked out. A plan of separation of these ions has been suggested. The conclusions set forth in this paper are based on experimental data secured through numerous determinations. These determinations involved about one hundred macro and over three hundred micro weighings. The authors are at present continuing the work of carrying out a complete separation of all ions listed above.

Mikroanalytische Bestimmung der Phosphorsäure nach der Molybdatmethode

ZusammenfassungEs wird über Versuche zur Bestimmung kleiner Mengen Phosphorsäure nach der Methode von F. L. Sonnenschein berichtet. Die Phosphorsäure wird als Magnesiumammoniumphosphat-Hexahydrat zur Wägung gebracht. Die angegebenen Beleganalysen zeigen eine grösste Abweichung von 0,07% (bezogen auf den P2O5-Gehalt) von der Theorie. Im Filtrat vom Ammoniumphosphormolybdat-Niederschlag können weitere Bestandteile bestimmt werden, da die Entfernung des nur in geringem Überschusse zur Anwendung gelangenden Molybdatreagenses keine Schwierigkeit bietet.

Studies in Qualitative Separations on a Micro Scale

A scheme for the separation, identification, and estimation of the ions of the thallium group ofNoyes andBray (thallium, silver, and lead) using a one milligram sample has been presented. The ranges of usefulness have been investigated, and the experimental data are reported. Results of trial analyses of samples are given. The detection of 0.2% of Thallium in the presence of silver or lead (one part of thallium in the presence of 1000 parts of either silver or lead) has been shown to be possible.

The use of potassium mercuri-selenocyanate as a reagent in qualitative microanalysis

(1) Potassium mercuri-selenocyanate was prepared and its reactions with the cobaltous, nickelous, ferric, ferrous, manganous, zinc, and cadmium ions were investigated. The limits of identification for these ions were determined.

A distillation method for the rapid determination of the volatile constituents of small samples of copper-zinc alloys

The sum of the volatile constituents of copper-zine alloys can be rapidly determined on samples of a few milligrams weight by heating at 1150° C. for 10 minutes in a gentle current of hydrogen The apparatus necessary, consisting of a Kipp generator, a gas wash bottle, a short piece of quartz tube and an electric resistance tube furnace, is available in almost every laboratory. In experiments performed the results were on an average about 0,5% (abs.) too high, the maximum deviations between individual determinations being 1,5% (abs.). Reasons indicating that, when dealing with commercial alloys, quantitative separations by fractional volatilization will not permit the obtaining of results of high precision are discussed with reference to the literature on the subject.