The behaviors of gases in metallic uranium have an importance in metallurgical point of view and an accurate estimation of a trace amount of gas is inevitable.
By the proposed method for hydrogen in metallic uranium, the author was able to determine 0.20.4ppm of hydrogen by the extraction in vacuo for 20min at 900°C instead of using a metal bath.
In case of the determination of oxygen, a metal bath of platinum was found superior than that of iron, and it was indicated that the uranium content must not exceed 10%. The estimation of oxygen was possible by extraction with fusion at 1850°C. Precision of analytical value was much increased by a mere mechanical cleaning of the metal surface.

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Uranium metal (1g) was dissolved in hydrochloric acid-hydrogen peroxide, the solution was evaporated to dryness and taken up in 40ml water. 5ml of 20% ammonium citrate were added and the pH was adjusted to 8.5 with aqueous ammonia. The whole was transferred into a separatory funnel and metals including cobalt were extracted with 10ml of 1×10^-3M dithizone carbon tetrachloride solution. The organic layer was washed with 10ml of 4N hydrochloric acid and passed through an alumina column (0.7cmφ×5cm) on which the dithizone complexes were chromatographically adsorbed. These were eluted with chloroform. The cobalt complex alone was separated and diluted with 2ml of chloroform. The absorbancy at 550mμ was measured using 1cm cell. Determination of above 0.1ppm of cobalt was possible with 10% coefficient of variation.

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A new analytical method for determination of a small amount of chlorine in uranium metal has been investigated by use of A. C. polarography.
The sample was dissolved in sulfuric acid and hydrogen peroxide, the excess hydrogen peroxide was decomposed by heating, the sulfuric acid concentration was adjusted to 9N, and A. C. polarogram was obtained by use of dropping mercury electrode. The amount of chlorine was calculated from the wave height (E_p=-0.15 V vs. Hg) produced by the electrode reaction,
2Hg+2Cl^-_??_Hg₂Cl₂+2e
The result was not affected by the presence of the other halogens and common elements as impurities in uranium metal.
170ppm chlorine was determined with good result by taking 1g sample and making it up to 10ml of the final solution.

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The sample was dissolved in nitric acid and sulfuric acid followed by the additions of thallous sulfate and potassium iodide. The silver coprecipitated with thallous iodide was taken up in sulfuric acid and hydrogen peroxide. The solution was evaporated to dryness and the residue was treated with acetic acid (60vol%) and p-dimethylaminobenzylidenerhodanine (0.004%).The light absorbency at 580mμ indicated the amount of silver. 0.44ppm silver in uranium metal could be estimated, provided 5g sample was taken and was made up into 5ml of the colored solution. The coprecipitation rate with thallous iodide was confirmed to be more than 95%, by using ^110m Ag as a tracer.

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A rapid method for the determination of sulfur in the range of 0.5γ to 100γ in a liquid or gas sample has been presented.
The sample is heated in a hydrogen stream over a nickel-silica catalyst at 1200°C. Sulfur is converted to hydrogen sulfide and absorbed in a dilute zinc acetate-sodium hydroxide mixture. The absorbed sulfur is determined spectrophotometrically at 665mμ by the Methylene Blue method.
The precisions for micro-amount of sulfur are±0.1γ, ±1γ and ±2.5γ for 0.5, 10γ and 50γ of sulfur, respectively.
The suitable sample sizes are 0.2g to 0.5g for the liquid, and 100 to several hundred ml for the gas.
Depending on the character of the sample, an analysis requires 30 to 50 minutes.
Analytical results on town gas and butadiene are given.

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A fluorescent X-ray analysis was applied to the determination of sulfuric anhydride and magnesium oxide in cement with several new knowledges.
The measurement was performed by a Rigakudenki X-ray Spectrograph with a specially designed sample chamber, and the contents of sulfuric anhydride and magnesium oxide were determined with ammonium dihydrogen phosphate (d=5.324Å) as an analysing crystal in a hydrogen atmosphere, by means of a gas-flow proportional counter and a pulse height analyser.
Calibration curves were prepared from commercial cements which contained various amounts of sulfuric anhydride and magnesium oxide. Each of the powder specimens was pressed to a plate of 2cm×3cm large under 300kg/cm² so as to avoid the error caused by an ununiformity in packing. The contents of sulfuric anhydride and magnesium oxide were measured by comparing the intensities of SKα and MgKα in the sample with those of the standards at every determination.Standard samples used in the experiment were a polished piece of sulfur crystal and a metallic magnesium plate, respectively.
Standard deviations of the analytical values obtained by the above-mentioned method and the calibration curves were 0.19% and 0.26% for sulfuric anhydride and magnesium oxide respectively. A determination of each of two components was made within ten minutes. One of the reasons of analytical error observed was attributed to the PKα emitted from the analysing crystal.

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A rapid method for the simultaneous spectrophotometric determination of niobium, tungsten and titanium using hydroquinone as the reagent was investigated.
The suitable wavelengths for the absorbancy measurements were selected and the calibration formulae for three elements were obtained. An examination of reproducibility of this method was made and a good result was obtained. Since the method does not require the removing of iron, nickel, chromium, cobalt, etc., it is suitable for the rapid determination of niobium, tungsten and titanium in heat-resisting steels and alloys.

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A rapid method of determination of a small amount of carbon (less than 0.05%) in steel has been developed, in which carbon is absorbed in barium hydroxide as carbon dioxide and excess barium is titrated with EDTA.
The carbon dioxide produced by combustion of the sample is absorbed in a barium hydroxide solution in 0.1N sodium hydroxide, to which is added a definite amount of alcohol to assure the complete precipitation by reducing the solubility of barium carbonate. The excess of barium ion in the solution retaining the precipitate is titrated with a standard solution of EDTA using Eriochrome Black T as an indicator and the amount of carbon is calculated. While the conventional method based on the acid-base titration is usually accompanied with a certain difficulty in the complete recovery of carbon dioxide owing to the limited concentration of the alkali, the proposed method by EDTA chelate titration has effectuated the rapid and simple absorption of carbon dioxide by increasing the alkalinity of absorbing solution and by introducing a porous glass absorption tube. The time required for an analysis of the steel sample was about 13min. and D₄(2)R was 0.0028%.

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Availability of the zinc complex of bis (2-hy-droxyethyl) dithiocarbamate (BHDTC) has been tested as a reagent for the spectrophotometric determination of bismuth, cobalt, copper, nickel and tellurium(IV), with which the BHDTC forms water soluble colored complexes in the presence of citric acid. The absorbance of Te-BHDTC solution is affected remarkably by pH of the solution and the time of standing after the reaction, while those of the complexes with the other metals remain constant in the range of pH from 5.5 to 9.5 and are stable for at least 25min.
The relation between absorbance and respective metal ion concentration keeps good linearity. The sensitivities for those ions are as follows ; Bi 0.021γ/cm² (at 363mμ), Co 0.075γ/cm² (at 470mμ), Cu 0.004γ/cm² (at 432mμ), Ni 0.010γ/ cm² (at 390mμ) and Te (IV) 0.04γ/cm² (at 420mμ). The extractability of the metal-complexes by several organic solvents has been also tested.

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Residual catalysts in high-polymers have a serious effect upon the characteristics of the products. The amounts of the residual catalysts are conventionally determined by chemical method including the ashing procedure, which are tedious and troublesome for the routine works in the quality control. A spectrochemical method has been presented by the author for the determinations of titanium, aluminum and iron in polypropylene by alternative current arc without an ashing procedure, as follows.
Prior to the arcing, 1 part of polypropylene powder was mixed with 2 parts of graphite powder containing 1% palladium as an internal standard, and 1 or 0.05 part of germanium dioxide, or, instead, 0.05 part of barium chloride. The excitation conditions were as follows: arc current 7A at A. C. 220V, carbon arc, and 50 seconds exposure. The suitable concentration range of the determinations were 0.0080.4% for titanium, 0.0040.4% for aluminum, and 0.002 (0.0004)0.01% for iron. The relative deviations by this method were ±8±15 per cent in the most favorable conditions. The method might also be applied to the determination of calcium, magnesium, silicon, zinc, etc. in polypropylene.

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When aluminum-clad uranium elements of a nuclear reactor are dejacketed with sodium hydroxide, it becomes necessary to determine free alkali (sodium hydroxide that is not combined with aluminum) in the solution.
A pH titrimetric method has been proposed for this purpose. To the sample solution triethanolamine is added to mask aluminum, and the solution is titrated with a standard hydrochloric acid while measuring the pH of the solution at regular intervals. A titration curve (pHml of hydrochloric acid) is then constructed and the end point is determined graphically. Sodium nitrate and sodium nitrite do not interfere with the determination of free alkali.
By the proposed method more than 0.5meq. of free sodium hydroxide in the presence of 5m mol of aluminum can be determined rapidly.
The method will also be useful in the processes of extraction of aluminum from bauxite.

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In order to simplify the spectrographic technique for aqueous solutions, a simple and stable electrode was devised. A copper rod of 5mmφ×7cm commonly employed as the ordinary standard electrode was incised vertically at the center of its top as the groove being 10cm in depth and 0.8mm in width, whilst a polyethylene reservoircup of 18mmφ×10mm was fitted to the rod as the brim of cup being lower 1mm from the top of the incised electrode. The groove pulled up the solution in the reservoir-cup successfully to the top of the electrode and from 1.7ml to one drop of the solution was subjected to the spectrographic analysis by means of the Feussner spark method.
This new electrode might be used successively without re-construction for various sample solutions only by washing the rod and the cup with 6N hydrochloric acid and water. The dependence of the method on various factors-consumption of the solution during the sparking, temperature increase in the cup, and the relation between the form of the electrode and the strength of the spectral lines was examined. The determination of magnesium in some underground water was carried out by employing the electrode and reasonable results were obtained.

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I. A simultaneous determination of C and H in Ta and Zr, was attempted by applying the method previously reported by one (Oda) of the authors for C and H in Ti and its alloys, and the following method was recommended.
In the same apparatus (Fig. 1) as used in the preceding Ti determination, the sample, 5g of Ta alone or 3g of Zr with 3g of Cu as a combustion accelerator was burnt at 1300°C in a current of oxygen (180ml/min), and the percent of C and H is calculated from the amount of CO₂ and H₂O obtained (Fig. 2, Table I). The coefficient of variation in the determination was 6% for both of C and H in Ta or Zr (Table II), and the lower limit of determination was 0.005% for each. The time required for an analysis (including both C and H determinations) was 20min.
II. Conditions for the combustion of C in Ta and Zr in high frequency furnace and for the succeeding determination of CO₂ have been investigated and a method for determining as low as 0.005% of C in Ta and Zr was presented (Fig. 3, Table III and IV).
III. The values by the simultaneous determination of C and H in Ta and Zr by the combustion gravimetry using a resistance furnace (method I) were compared with those obtained by the high frequency furnace combustion method (C in Ta and Zr, method II) or the vacuum fusion method (H in Ta), and good agreements were obtained (Table V). Discussions were given for the practical usefulness of each method.

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The author revealed in the preceding report that chloranil was determined satisfactorily by the polarography in 50% alcohol solution. Since chloranil is readily obtained as a stable end product from various aromatic compounds by the oxidation with potassium chlorate and hydrochloric acid, the applicability of this oxidation to the quantitative analysis has been preliminarily examined in this paper for several aromatic compounds, in which phenol has been found to be oxidized quantitatively to chloranil.
The author recommends a method whereby the chloranil derived from phenol by KClO₃-HCl oxidation is extracted with ether and is determined by the polarography in 50% alcohol at pH 3.4 using N/10 potassium nitrate as a supporting electrolyte. This offers an easy and accurate method for the determination of phenol.
The method was applied to the determination of phenol in naphthalene.

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The author reported in the preceding publication that beryllion, one of azo-chromotropic acid compounds, was useful as a color reagent for boron in concentrated sulfuric acid solution. In this paper the application of neo-thorin, the same kind of compound as beryllion, to the determination of boron has been described.
The effects of concentration of neo-thorin and sulfuric acid, and time of heating on color development and also stability of the color were examined.
For the determination of boron, add 1.50ml of 2×10^-3M neo-thorin solution to the sample containing up to 10.0μg of boron, then add concentrated sulfuric acid and adjust the total volume to 10.0ml. Warm the mixed solution for 15min. in an air-oven at 35°C. After cooling, measure the absorbancy of the solution at 635mμ against the reagent blank as a reference.
In the recommended procedure Beer's law was maintained from 0.0 to 1.0ppm of boron at 635mμ, and the molar extinction coefficient of boron was 6, 410. The proposed method was sensitive and, in connection with the distillation procedure, suggested the possibility to develop a method for the detemination of boron.

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A new coulometric titration device was presented in which the electrolysis at a constant current was carried out by supplying an electrolyte solution into an external generating cell at a given flow rate and the flow of the electrolyte was automatically stopped simultaneously with the cutting off of the generating current. By this means of synchronization, a given concentration of the external generating reagent could be maintained throughout the titration regardless of frequent intermissions of the electrolysis.
In the experiment, a mixed electrolyte solution of 0.5M sodium nitrate and 0.02M acetic acid was used and the chloride ion was titrated with silver ion generating from a silver electrode. The end point was determined amperometrically and the titration was found to give good results. It was especially satisfactory when the "hold up" of the cell was small. By use of this means, the amount of liquid flowing out dropwise was not increased unnecessarily large in amount even with the repetition of discontinuous electrolysis and this offered an advantage for determination of the end point without any correction for the dilution in the reading of the indicator current.

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Coulometric titration with externally generated silver ion was successfully applied to the determination of chlorine in organic compounds.
Organic compounds were decomposed either with combustion in oxygen-filled Schöniger's flask or with liquid ammonia and metallic sodium. After the decomposition, chloride ion was titrated coulometrically with externally generated silver ion using the same procedure as reported previously by the author {S. Suzuki: this journal, 11, 228 (1962)}.
The determination of chlorine was carried out with good results as shown in Table I or II after the decomposition either with Schöniger's method or with liquid ammonia and sodium, respectively.

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Attempts have been made to separate berberine, atropine, and scopolamine by use of weak cation-exchange resin (Duolite CS-101, 100200 mesh).
An aqueous solution containing a mixture of berberine hydrochloride, atropine sulfate, and scopolamine hydrobromide was passed through a column of Duolite CS-101 (NH₄-form) for adsorption of the alkaloids. A portion of scopolamine was eluted unadsorbed and the rest of it was liberated by washing the column with water. The column was then treated with 0.2N NH₄Cl for liberation of atropine and finally with 1N Na₂CO₃ for liberation of berberine.
Each alkaloid thus liberated was determined by the amperometric titration.
The recovery was above 85% for atropine and scopolamine and above 95% for berberine.

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1. Extraction method. It had been already reported that an addition of ethanol extended the upper limit of the determination of nitrite ion by Griess Romijn reagent since the azo-dye was soluble in ethanol. 0.010.35ppm of NO₂^--N could be determined by this means. The author presented a new method in which butanol cyclohexanol was used instead of ethanol and the azo-dye was extracted into the mixed solvent. 50ml sample solution containing NO₂^- was treated with GR reagent for development of coloration, hydrochloric acid was added to about 1.7N, and the dye was extracted with 10ml of the mixed solvent (7:3). The estimation of ultra micro-amounts (0.0020.07ppm) of NO₂^--N was made with good sensitivity.
2. Alkali addition method. The dye was soluble in alkali and gave orange yellow coloration, which was used by the author in the photometricdetermination of NO₂^-. In the recommended procedure, GR reagent was added to a neutral sample solution, and it was made alkaline with sodium hydroxide solution after a sufficient time for the completion of color development. The absorbancy at 480mμ was measured for the determination of 0.051.0ppm NO₂^--N.

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The convection electrode, which has already been reported by the author in Nippon Kagaku Zasshi, 81, 98 (1960); 82, 46 (1961), is applied to the amperometric titration. It is constructed as follows. An aluminum disk of a pulley-shape coated with paraffine wax is rotated horizontally at a constant rate (3600rpm) in the titration vessel (electrolytic cell) near the stationary platinum-wire electrode, which is set on the side wall of the cell.
Current-potential curves of Fe²⁺ in 0.1N H₂SO₄ and Ag⁺ in 0.1M KNO₃ are investigated and fairly reproducible waves are obtained. The systems of Cr₂O₇^2--Fe²⁺, S₂O₃^2- -I₂, Cl^--Ag⁺, and Fe(CN)₆^3- -Ag⁺ are studied as the typical reactions, which are unaffected by dissolved oxygen.
10^-6N of Cr₂O₇^2- and S₂O₃^2- can be determined with the error of about 2%, and 10^-4N of Cl^- and Fe(CN)₆^3- with the error of about 3% and 1% respectively. The proposed method is more accurate especially at low concentrations than the ordinary method with a rotating platinum electrode. Ethyl alcohol, instead of acetone previously used by Laitinen et al., is added to the sample solutions at the precipitation reaction to decrease the solubility of precipitates, and good results are obtained.

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