Spectrophotometric determination of small amount of vanadium utilizing its catalytic action on the reaction of aniline with hydrogen peroxide has been presented.
An aliquot of a sample solution is taken in a Nessler tube and diluted to 2ml with water. After an addition of 10 ml of sulfuric acid, it is water-cooled to room temperature, and a half ml of 3% hydrogen peroxide solution added and water cooled again to room temperature. A half ml of aniline solution (0.1 g aniline/50ml sulfuric acid) is added and mixed by shaking. The tube is immersed in boiling water to develop color for 8 min., and then water-cooled. The absorbance at 475 mμ of the solution is measured to determine 0.020.2μg vanadium.

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Methods of determination of sulfur oxides in a large-scale flue was examined. The heating of sampling tube was successfully done by an application of steam-jacket tubes.
Theoretical values agreed well with those obtained either by JIS neutralization method, by barium chloranilate method, by Arsenazo-III method, or by sulfur dioxide detector tube method. Sulfur trioixde in the flue gases was simultaneously determined and was found to be less than 3%, the remaining 97% or more being sulfur dioxide. Since, therefore, the amount of sulfur dioxide may represents the concentration of sulfur oxides in the flue gases, the use of the sulfur dioxide detector tube is a convenient method for the measurement of the whole concentration of sulfur oxides in the waste flue gases.

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The work was undertaken to determine the amount of 4-chlorophenyl-2, 4, 5-trichlorophenyl sulfone (Tetradifon, Tedion) in emulsion concentrates, wettable powders, and dust formulations. A rapid and simple semi-micro procedure has been devised by utilizing the dry thin-layer chromatography with ultraviolet absorption procedure.
The procedure is as follows : Apply one ml of ether solution containing about three mg of Tedion to an alumina plate prepared by "dry method ". Develop the plate ascendingly with n-hexane-ether (9:1) until the solvent front reach a preliminarily marked line 10 cm apart from the original line (development needs 68 minutes). Dry the plate at room temperature, and identify the Tedion fraction (R_f 0.3) under ultraviolet rays (250mμ), and mark on it. Collect the alumina powder containing Tedion into a suction and elution tube {This Journal, 14, 207 (1965)}. Elute it with methanol. Measure the absorbances of the solution at 250 mμ and 277 mμ, respectively. Then, compare the difference between them with a calibration curve, and calculate the amount of Tedion.
The proposed method was applied to determine the amount of Tedion in the formulations and gave satisfactory results. The recovery and σ are, respectively, as follows. The emulsion concentrate, 100.9% and 0.74% : the wettable powder, 100.5% and 1.05% : the dust formulation, 100.3% and 0.24%. It was also applied to the investigation of the degradation of Tedion after its formulation.

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A new tensammetric titration of metal ions with 8-hydroxyquinoline (oxine) has been developed utilizing the tensammetric wave of oxine which appears at a potential of positive polarization of the dropping mercury electrode (DME).
Oxine produces two a. c. polarographic waves in ammonium acetate buffer solution of pH 6.7 on a potential more positive than the electrocapillary maximum. The first wave at about +0.15V vs. SCE seems to be the "transition wave" which is due to both the electrolytic oxidation of mercury and the adsorption of mercurous oxinate formed at the DME, but the second wave at about -0.05V vs. SCE is purely tensammetric in character.
The height of the second wave is proportional to the concentration of oxine between 3 × 10^-6M and 3 × 10^-5M. When metal ions such as Zn²⁺, Cu²⁺, Ni²⁺, Fe³⁺, In³⁺, U⁴⁺ and Mo⁶⁺ are added to the solution, these ions react quantitatively with oxine and the height of the tensammetric wave is decreased. This fact can be applied to the detection of the end point of the titration of very dilute solution (10^-5M10^-6M) of these metal ions with oxine. The relative standard deviation of the method was ±2% or better for the titration of 2 × 10^-5M Cu²⁺ or Zn²⁺.

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A new method for the a. c. polarographic determination of gallium using perchloric acidammonium thiocyanate as supporting electrolyte solution was studied and applied to iron and steel.
The procedure is as follows. One g. sample is decomposed with the mixture of nitric and hydrochloric acids, and evaporated to white fume after adding perchloric acid. After reducing ferric ions with 1-ascorbic acid, gallium is extracted with MIBK from hydrochloric acid solution and back-extracted with water. This treatment is repeated once more, and water is removed by moderate evaporation. Perchloric acid (60%) 0.3ml and ammonium thiocyanate solution (50.0%) 5.0 ml are added and diluted with water to exact 25 ml. The oxygen dissolved in an aliquot is removed completely by passing nitrogen gas. This solution is applied to an a. c. polarography under the voltage between -0.55 and -0.85V against mercury pool and the amount of gallium is determined from the wave height of -0.75V.
This method is carried out within an absolute error of 0.005%. The time required for an analysis is about 90 min. The 38 elements coexisting commonly in iron and steel scarcely interfere.

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Flame photometric method has been successfully adopted to the determination of micro amounts of manganese (0.00020.01%, sample taken 0.1 g) in pure iron. This determination, scarcely interfered with the co-existing elements, was found to be more suitable than colorimetric determination. The sensitivity was much increased by spraying manganese into oxyhydrogen flame after a TTA extraction. The recommended procedure is as follows.
One tenth g of sample is decomposed with the mixed acids (HCl, HNO₃ and HClO₄) and iron is removed with a MIBK extraction. Hydrochloric acid layer is evaporated to almost dryness after perchloric acid is added. Five ml of 1 M ammonium tartrate and 8 ml of the mixed buffer solution (pH 8.5) are added, and the solution is diluted to 25 ml. Manganese is extracted with 10 ml of 0.005M TTA-mixed ketone (50 v/v % of 2-octanone in MIBK) solution. The organic layer is sprayed into oxyhydrogen flame (O₂ : 1.0 kg / cm², H₂: 0.13 kg /cm²) and manganese is determined from the intensity at 403.3 mμ.
An analysis was carried out in about 70 min.within an absolute error of 0.0001%. Twenty μg of 21 elements commonly found in pure iron hardly interfered when 5 μg of manganese was determined.

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Spectrophotometric determination of copper with thiomalic acid was investigated.
Thiomalic acid reacts with copper to form a water-soluble reddish violet complex with an absorption maximum at 530 mμ.
Fundamental conditions for the determination were studied, the optimum conditions being 10 ml of 0.6% thiomalic acid solution per 100 ml of total solution containing 1% hydrazine sulfate, pH 5.5, and the wavelength 530 mμ.
The Beer's law obeyed over the range of 1 to 30 ppm Cu, and the molar extinction coefficient was 1.27 × 10³.
The mole ratio of Cu to thiomalic acid was proved to be 1 : 1 both by continuous variation method and by mole ratio method.
The influence of Ni²⁺, Co²⁺, Fe³⁺ etc. was examined.

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The sample is dissolved in nitric acid or perchloric acid, and an aliquot of the solution is. taken. When more than 40 mg of Cu, or nickel and chromium, are present, yttrium should be preliminarily isolated by TTA extraction. When the amount of Cu does not exceed 40 mg, it can be masked by thiourea. After the removal of the above interference, Arsenazo-III is added and the 660 mμ absorbance is measured at pH 2.5. Reference on the calibration line gives the amount of yttrium.
Yttrium-Arsenazo-III complex obeys Beer's law over the range of 01 ppm Y, and the sensitivity of the determination is 0.1 ppm in final solution.

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The activation of silica gel adsorbent and the efficacy of developing solvents in thin-layer chromatography of bufogenin were studied. The optimum activating conditions of silica gel depended more or less on its quality, but, generally, were 3060 min. standing at room temperature after spreading and the succeeding heat for 6090 min. The recommended developing solvents were; acetone-chloroform-cyclohexane (3 : 3 : 4), acetone-cyclohexane (3 : 7), n-hexane-ethyl acetate (1 : 9), and methanol-ethyl acetate-cyclohexane (2 : 6 : 7). Twenty-four bufogenins and sterins were detected and identified by the proper combination of the solvents or by the aid of two-dimensional development. The separation of 3-hydroxy isomer and 14-anhydro isomer and the determination of bufogenin were also investigated.

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Copper 8-hydroxyquinolate was precipitated from homogeneous solution using 8-acetoxyquinoline as the parent material of 8-hydroxyquinoline in which the fundamental condition for the precipitation, the morphology of the precipitate. obtained, and the separation of copper from diverse ions were studied. About 1 to 100 mg of copper can be precipitated quantitatively. The precipitates are composed of needle crystals of about 100 μ × 0.2 μ. Copper 8-hydroxyquinolate precipitated in the presence of cadmium from the homogeneous solution of pH 3.5 was utterly free from cadmium.

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Thiosemicarbazide forms a soluble blue complex with copper (II) in acidic aqueous solution. The complex has two absorption peaks at 356 mμand 700 mμ, respectively. The peak at 356 mμ is high enough so that an almost coloress solution containing 3 ppm of copper (II) and thiosemicarbazide has an absorbance of 0.26 at this wavelength.
Copper (II) (0.52.0 ppm) is determined by the measurement of 356 mμ absorbance after an addition of 0.05 g. of thiosemicarbazide with 1.0 ml of 35% hydrochloric acid to 50ml of solution. The calibration line is given by a regression equation y=0.0874x+0.0018, where y is the absorbance at 356 mμ for the copper (II) concentration (ppm) x. The standard deviation is 0.02 ppm at the level of 1 ppm.
There hardly was any substance except iron (III) which would give much interference with the determination of copper (II).
Measurements by the continuous variation method and the molar ratio method showed that the composition of the complex was 1 (Cu) : 2 (thiosemicarbazide) in molar ratio.
Solution, below pH 4, containing the complex did not show any change in its absorbance after having been kept at 15 to 40°C for 24 hours.
The application of this method to industrial wastes, preliminarily treated, was successful. The rapidity and simplicity are the advantages of this method.

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A method is described for the spectrographic determination of strontium and calcium in bone ash. Two parts of carbon powder and 1 part each of potassium sulphate and bone ash were mixed, loaded into a graphite sample electrode, and burned in an interrupted a. c.-arc of 3 amperes. The line pairs were: Sr 4077.7Å/Ca 3968.4Å or 4226.7Å, Ca 3644.4Å/Ti 3642.1Å. The lower determinable limits by the present method were 10^-4 for Sr/Ca-ratio and 20% for calcium, and the coefficient of variation estimated statistically were below 5.3% for calcium and 12% for Sr/Ca-ratio.
Mean values of calcium content and Sr/Ca-ratio in human bone ash, 34% and 0.36 × 10^-3, were obtained from results on 20 samples by the present method.

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