The carrier precipitation of μgmg range of indium in 25ml of diluted nitric acid (<0.1N) with hydrated manganese dioxide has been studied using In-114m as a tracer, and the results were discussed by assuming the adsorption of indium on a surface of the collector. The μgmg range of indium in 25ml of solution was almost completely coprecipitated with 27.5mg of manganese carrier. The carried-down percentage of indium decreased effectively by the elevation of initial concentration of indium above 2mg/25ml following the Freundlich's isotherm: log (In)_ad=log k+1/n log (In)_ini, where _k and _n are constants. The amounts of the carrier also showed the effect on the entrained percentage of indium according to the equation: log (In)_ad=a log (Mn-Mn⁰)+log b, where (Mn-Mn⁰) denotes the quantities of precipitated manganese and a, b are constants.
The presence of more than 10^-6mol/l of EDTA, 0.1mol/l of H⁺, 10^-4mol/l of Pb²⁺ or 10^-4mol/l of Fe³⁺ diminishes the recovery of μg quantities of indium.

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A surface ionization method was applied to the determination of the abundance ratio of copper isotopes.
For the practical point of view, the single-collector method was proved to be better than the double-collector method. The experimental conclusions on the single-collector method are as follows.
(1) The accuracy is ±0.5% (standard deviation).
(2) Copper nitrate {Cu(NO₃)₂} sample gives better results than copper chloride (CuCl₂).
(3) The combination of a rhenium ionization filament and a tungsten vaporization filament gives the best results among the other double or single filament arrangements.
(4) The ⁶³Cu⁺ ion current, the currents of ionization filament and vaporization filament, and the time from the initiation of heating of the filament to the measurement of ion-peak (⁶³Cu⁺, ⁶⁵Cu⁺) should be held constant in a series of experiments.
(5) The same ionization case should be used to compare the abundance ratio of copper isotopes.
(6) The time required for a measurement is about 2 hours.

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RHgX type alkylmercury compounds were subjected to gas chromatography on 13 different columns to know the relation between chemical structure of compound and its retention volume. Organic mercury compounds were eluted in the order from smallest C numbers to larger C's. The difference in X did not generally affect the retention volume for the compounds with the same R, although a few columns were found to separate these. Theoretical plate numbers and decomposition degrees of organic mercury compounds were shown.

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As little as 0.16 to 3.0ppm of zirconium and 0.16 to 3.4ppm of hafnium were spectrophotometrically determined with Chromazurol S (CAS).
The sample solution containing 0.6 to 0.7ml of hydrochloric acid was diluted to 10ml with water. One ml of 0.257% CAS solution and 25ml of 0.25M sodium acetate solution were added, and the mixture was diluted to 50ml with water. Thus final pH became to 1.4. The absorbance at 555mμ was measured against the reagent blank as a reference.
Iron(III), phosphate, oxalate, citrate, EDTA, and hydrogen peroxide even in small amounts interfered seriously.
The mole ratio of Zr-CAS or Hf-CAS in either complex under the given condition was 2: 5.
A simultaneous determination of 8 to 84μg of zirconium and 8 to 160μg of hafnium by the difference of decolorization in their complexes with hydrogen peroxide was also carried out.

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Methods are described for the spectrophotometric determination of lanthanum, neodymium, gadolinium, erbium and ytterbium with Eriochrome Black T. The sample solution containing 580μg of rare earth element is transferred to a 25ml volumetric flask. Eriochrome Black T is added and pH is adjusted to9 by a buffer solution of ammonium chloride and ammonium hydroxide. Potassium cyanide is added to eliminate the interference of many elements in the sample solution. After diluting to the mark and allowing to stand for 15 min., the absorbance is measured in a 10mm cell at 640mμ (indirect method) or 510mμ (direct method). Beer's law is obeyed in the concentration range 090μg rare earth element per 25ml.
Results of the continuous variation method indicate that the mole ratio of rare earth element to Eriochrome Black T is 1: 1. Apparent molar absorptivities at 640 and 510 mμ are given for the five rare earth elements.

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A spectrophotometric method for the determination of dithianone, 2, 3-dicyano-1, 4-dithiaanthraquinone, was studied and established. The recommended method is as follows. A sample containing 150mg of dithianone was weighed into a 100ml measuring flask and it was filled up with acetone. After one hour of standing with occasional shakings, one ml of the supernatant was pipetted into a 50ml measuring flask and made up to 50ml with methanol. Five ml of the solution was pipetted into a 25ml measuring flask. The flask was filled up with 3% aqueous sodium sulfide solution held at 25°C and immediately the absorbancy of the solution at 375mμ was measureed. The amount of dithianone was calculated from the calibration curve obtained by treating 5ml of the standard solution containing 100200μg of dithianone through the procedure mentioned above.
It was clarified by thin-layer chromatography that commercial products of dithianone did not contain any substance which interfered with the analysis. The method was proved to be applied to the determination of dithianone in its formulations containing other fungicides, i.e. phenylmercuric acetate, Cellocidin or basic cupric chloride.

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p-Chlorophenyl p-chlorobenzenesulfonate (CPCBS) and bis(p-chlorophenoxy) methane (DCPM) in emulsifiable concentrate or wettable powder weredetermined by gas-liquid chromatographic method using benzyl benzoate as an internal standard. A Shimadzu gaschromatograph GC-2B with a thermal conductivity detector was used. The stainless columm (4mm×2m) was packed with 15% FS 1265 as stationary phase on a support of Chromosorb W (acidwashed). The columm temperature was adjusted to 200°C and the flow rate of the carrier gas, helium, was maintained as 80 ml per minutes. The emulsifiable concentrate was injected to gaschromatograph after being mixed with the internal standard. The cornpounds in wettable powder were extracted with a 1+1 mixture of acetone and toluene containing benzyl benzoate and applied to gaschromatography. The relative retention times of DCPM and CPCBS against benzyl benzoate were 2.17 and 5.88, respectively. The results of analysis of technical products and formulations were tabulated in Table II. It was proved by gas chromatography that DCPM isolated from technical product by partition chromatography contained some impurities.

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Improvements have been made on the spectrophotometric determination of nickel by Sandell's method and a method for determining exchangeable nickel in soils without separation has been established. The main point of improvement is the addition of a stabilizing agent for the 1:2 nickel-dimethylglyoxime complex initially formed by the ammonia-bromine method. The authors found that the color intensity of the 1:2 complex did not vary within 3 hours at 20°C by the addition of ammonium acetate or a mixture of ammonium acetate and citric acid before coloration (Fig. 1 and Fig. 2). The absorbance at 445mμ was not affected by the presence of considerable amounts of metallic ions except for copper (Table I), and, therefore, this method is suitable for the determination of exchangeable nickel in a number of soil samples. Comparing with the Sandell's method, the recommended method was more accurate (Table II). Determination of nickel in plants grown on the serpentine soil was possible provided that the content of copper was not so high (Table III).

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In the simultaneous C, H and N determination apparatus involving a thermal conductivity measurement, a choking of carrier gas flow in the carbon dioxide absorption tube may cause a serious interference with the accurate quantitative analysis.
Soda asbestos generally used causes the choking in the part of carbon dioxide absorption, so that a preventive method was studied. Lithium hydroxide of 1020 mesh was poor in quantity of carbon dioxide absorption, and it would not be practical, while, on the other hand, it was not given any change of form before and after the absorption.
Therefore, it was mixed at a volume ratio of 1:2 or 1:1 with the soda asbestos and packed in the absorption tube with 10cm length, and good results were obtained. The capacity of the carbon dioxide absorption with the mixture was found to be reproducible for about 150 times of analyses with 2.02.5mg of acetanilide in the 1:2 ratio mixture and for 120times of analyses in the 1:1 ratio mixture and practically no change in calibration values was observed. With the similar object, polyethylene pieces of O. D.=2.3mm I. D.=1.2mm and length=23mm were also studied.
All the mixtures above mentioned showed to be available to the absorption limit of reagents packed and the analytical accuracies have been illustrated in Table I.

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For the photometric determination of traces of fluoride using alizarin complexone (ALC), a commercially available reagent, "Dotite Alfusone", has been used. With 2.52% of La-ALC (1:1) chelate, potassium hydrogen phthalate and hexamethylenetetramine are contained in the soluble reagent as buffer agents. The buffer action is strong enough to keep the pH of the solution at 5.1 in the following procedure.
A weakly alkaline solution containing 1 to 30μg of fluoride is treated with 5.0ml of 2.5% "Dotite Alfusone" solution (6×10^-3M of La-ALC chelate) and 10ml of acetone, and the resulting solution is diluted to 25ml with water. After standing for 1.5 hours, the absorbance of the solution is measured at 620mμ using a blank as reference.
The preparation of the reagent solution is simple and easy. The established method is more sensitive (molar absorptivity =1.3₈×10⁴) than the authors' previous work in which a composite reagent solution (La-ALC chelate, buffer solution and acetone) was used.

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A method has been proposed for the gas-liquid chromatographic determination of 3, 4-dichloropropionanilide (DCPA) in technical products and emulsifiable concentrates. The DCPA was dissolved in toluene and analyzed with added benzyl benzoate (BB) as an internal standard by a Shimadzu Gas Chromatograph GC-2B with a thermal conductivity detector, using helium as carrier gas, the flow rate of which was maintained as 100ml per minute. The column (4mm×1m, stainless steel) used contained 30 weight per cent Apiezon grease L as the stationary phase and 1 weight per cent Emulsogen WS-32 as the tailing reducer on the support of Celite 545 and the column temperature was adjusted to 230°C.
A calibration curve in the 0.31.6 weight ratio (DCPA/BB) was found to be almost linear and passed through the zero point. The standard deviation and the mean recovery of the proposed method were calculated to be 1.35%, and 99.9%, respectively for the prepared emulsifiable concentrates.

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When total acid contents and formol titration of many Saké (Japanese rice wine) are carried out, the determination of the end points by observing the change of color of the indicator visually was considered to be difficult. In order to avoid such troubles, as well as individual errors, an automatic stopping titrator to indicate the end point precisely has been deviced to the trial.
Silicone phototransistor was used as a light detector which controls the SCR by the change of photoelectric current and it operates the electromagnetic valve of buret, employing bromothymol blue and phenolphthalein as an indicator.
From the repeated experiments on Saké, the values measured are stable and the results are found to be reliable. When it is compared with the automatic titrator of glass electrode, the price is low. At the same time, it is considered to be so effective that many tititrations are carried out accurately, rapidly and easily.

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Spectrophotometric determination of germanium with phenylfluorone is considered to be one of the excellent methods, but the reaction is slow and troublesome to carry out. Rate of this reaction is accelerated appreciably by the addition of cethyl trimethyl ammonium chloride (CTMAC) and then the coloration is developed immediately at room temperature (2530°C). The sensitivity is about twice as much as that without CTMAC.
The solution containing 18μg Ge is transfered to a 50ml volumetric flask, and enough hydrochloric acid is added to make its total content in the solution equivalent to 5ml of concentrated acid. To this solution are added 5ml of 0.25 percent polyvinyl alcohol (Polmerization grade 1400) solution, 5ml of 1 percent CTMAC solution and 10ml of 0.04 percent phenylfluorone ethanol solution and then it is diluted to 50ml with water. The absorbance of the solution is measured at 505mμ against a blank. The molar extinction coefficient is 1.71×10⁵. The calibration curve shows to be linear over 0.020.16ppm Ge.

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An application of I₂-CH₃OH method for the chemical separation of metallic Ni from NiO is investigated. The metallic Ni is quantitatively dissolved when the material (180 mesh) is stirring with 50ml of 4% I₂-CH₃OH for 15min. at 30°C, and an aliquot of solvent is dried and dissolved in acid.
Nickle separated by this procedure are determined by photometrical method, obtaining satisfactory results.

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