Studies on the Determination of Arsenic. V : Volumetric Determinations of Reduced Metallic Arsenic

Dichromate, permanganate, Chloramine, ceric sulphate and iodate methods are applied to the determination of metallic arsenic which is reduced with stannous chloride or sodium hypophosphite. Dichromate and Chloramine methods are recomended ; the other methods are accurate but less applicable

Studies on the Determination of Arsenic. I : Determination of arsenic in Iron, Steels and Iron Ores

1. A reduction of arsenic compound to arsenious compound with potassium iodide takes place perfectly in hydrochloric acid solution from 2 N to 6 N or in sulphuric acid solution from 3 N to 6 N ; the use of sodium sulphite is most suitable to consume the liberated iodine. Influences of molybdenum, copper and iron on the iodometric determination of arsenic were investigated. 2. Several methods to precipitate arsenic as sulphide were tested and the method with sodium sulphide is most suitable for a routine analysis. 3. An analyitcal procedure for iron, steels and iron ores containing comparatively much arsenic is decided, in which arsenic is separated out with sodium sulphide and determined by iodometry. Analytical results of arsenic in some of iron, steel and limonite are shown. In conclusion the author wishes to express her heartfelt thanks to Prof. H. Goto for his valuable suggestions during the work

Studies on the Determination of Arsenic. VI : Determination of Arsenic in Bismuth, Antimony and Tin

The determination of arsenic in non-ferrous metals was studied by means of iodometry and of colorimetry after it had been separated in metallic state. In this report, the influence of bismuth and antimony on the molybdenum blue coloration was experimented, and the condition of reduction with stannous chloride and the separation of arsenic in bismuth, antimony and tin metal solutions were described in detail and analytical procedures for arsenic in respective metals were proposed

Semimicro Determination of Beryllium in Copper-Beryllium Alloy

A simple method for the determination of beryllium in copper-beryllium alloys by a small amount of the sample was studied. After separating beryllium from copper and others by precipitate with guanidine carbonate, beryllium was determined colorimetrically with "aluminon". The most suitable procedure for this method was established

Determination of Free Lime in Slag

Applying the method of McPherson and Forbrich by the use of ethylen glycol, the determination of free lime in slags was studied. The powdered slag sample was heated at 60～70℃ with ethylen glycol to extract free lime and after filtration, the filtrate was titrated with standard hydrochloric acid to determine free lime. By this method, free lime in several kinds of slags and cement was determined and the results obtained were shown. This method was carried out successfully within about 30min without any complicated procedure

Microdeterminations of Arsenic and Antimony in Metallic Germanium and Germanium Dioxide

The method for the determination of minute amounts of impurities in high-purity germanium was studied and a simple method for the determination of arsenic and antimony was successfully completed, by using only a small amount of sample. For the determination of arsenic, germanium was removed as germanium tetrachloride by distillation, or by dissolving the sample and, omitting the distillation and the isolation processes, reducing quinquevalent arsenic to trivalent arsenic and extracting with carbon tetrachloride after the addition of sodium diethyldithiocarbamate, arsenic was determined as molybdenum blue. Antimony was determined after removing germanium tetrachloride by distillation or separating antimony by coprecipitation with manganese dioxide, determined by the methyl violet method, a sensitive method of determination was developed by the present study. In this way, the determination of up to 0.1 p.p.m. of arsenic and 0.01 p.p.m. of antimony in metallic germanium was possible

Fluorescene Analysis. XIV : An application of Chromatography with Filter Paper

A chromatography with a filter paper was carried out under the ultraviolet ray. Oxine, Cochineal and Rhodamine B were used as the developing reagents and the absorptions were made in solutions neutral, ammonia alkaline or containing sodium tartarate. Chromatograms of lead, copper, cadmium, zinc, nickel, cobalt, manganese and iron were shown by their photographs

Colorimetric Determinations of Niobium and Tantalum

Niobium develops a stable yellow color and tantalum does not with pyrogallol at pH 4.6-6.8 in the solution containing sodium sulfite, which is applicable for the photometrical determination of niobium. As little as 0.4γ per ml can be determined. Tantalum develops a stable yellow color and niobium does not with pyrogallol in the acidic solution containing sulfuric acid in less than 3N and a minute amount of sodium sulfite. Applying the coloration, as little as 0.05 mg per ml can be determined photometrically. Acetic acid, citric acid, succinic acid, phthalic acid, nitric acid, hydrochloric acid and perchloric acid do not interfere the both determinations

Determination of Tungsten in Iron and Steel. I : Investigations on the Perchloric Acid Method

The conditions for the determination of tungsten in iron and steel have been studied by the use of perchloric acid. Tungsten can be precipitated quantitatively with a single fuming of perchloric acid by the following treatment : the sample is dissolved in aqua regia and evaporated to the white fume after an addition of 50 ml of perchloric acid ; after cooling, 30 ml of 6N hydrochloric acid is added and its final volume is brought to 150 ml with water so as to adjust the concentration of hydrochloric acid between 1～1.5N. The solution is warmed at 70°～80℃ for an hour and then filtered. Applying this method also to the rapid determination, tungsten can be determined within about 20 minutes