The separation of trace amounts of anthracene from phenanthrene is very difficult even with the zonerefining method. The authors have found that the addition of a small quantity of maleic anhydride to the original phenanthrene sample greatly enhances the efficiency of zone-refining.
Anthracene reacts with maleic anhydride in the melted zone of phenanthrene to form an addition compound whose segregation coefficient is much different from that of anthracene itself. Therefore, the efficiency of zone-refining is enhanced.
The determination of anthracene was made by measuring the absorbance at 376 nm in cyclohexane; the limit of detection by this method was 0.002%. A commercial sample of guaranteed-grade phenanthrene contained about 1.2% anthracene. After 30 passes of the sample through the heated zone in the presence of 2.8% maleic anhydride, no anthracene could be detected in the purified product.
The present technique of improving efficiency of the zone-refining method by adding a third substance which in the melted zone reacts with the impurity to form a compound of different segregation coefficient may be applied to various cases.

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A quantitative analysis by electrolysis with mercury pool cathode has been applied to alkali and alkaline earth metal ions during descending paper chromatography. In this method, I employ a mercury electrode having high hydrogen overvoltage, and so I can suppress the dark current and apply acidic developers in addition to the neutral developers.
The determination obtained by this method has better sensitivity due to the measurement of the current in electrolysis for alkali and alkaline earth ions than the conductometric method with Pt-electrode which has been already reported. The reason of use of the descending development is that a rapid passing descending developer decreases the raising temperature in electrolysis and the variation of the developer's component.
The D. C. voltage applied is maintained constant in the range of 3.0V to 4.0V. Mercury negative electrode is made from polymetacrylate resin, which provides a long mercury pool ditch 3×18 ×2 mm, and the surface of mercury electrode is kept fresh by constant supply of mercury. The filter paper is clamped between the flat graphite anode and above mentioned mercury pool cathode, and both are placed 35 cm below the original point.
After having the paper been clamped and mercury poured to the ditch cathode, the development of chromatography is carried out.
Selected developers are methanol for alkali metal ions, while ethanol or 80% (v/v) ethanol for alkaline earth metal ions.
A calibration curve is ordinarily obtained from the height of the peak current by electrolysis for each separated ion during descending development. By this method, for example, sodium chloride can be measured as far as 0.058% in concentration, and 1.2 μg of Na⁺ (3.0 μg as chloride) in quantity. And its deviation in current of peak is below 0.7% (the region of 350 μg as chloride i.e. 1.220 μg of Na⁺). Potassium chloride is measured with deviation of 0.4% for 550 μg as chloride; whereas alkaline earth metal chlorides within the region of 1550 μg are measured with deviation of 2.0±0.5%.

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Quantity analysis of sodium sulfide had been studied repeatedly, but the analysis of the mixture of sodium sulfide and sodium hydrogensulfide, and the mixture of sodium polysulfide and sodium hydrogensulfide, has not been established. The author studied this analysis because it was necessary in the procedure of the reduction of aromatic nitrocompound with sodium hydrogensulfide. Finally, two methods were found to be suitable. The first method is based on the fact that sodium hydrogensulfide, sodium sulfide and sodium polysulfide consume the same mol of iodine, respectively, but in the case of neutralization with 1N hydrochloric acid, sodium hydrogensulfide needed the same mol of hydrochloric acid. On the other hand sodium sulfide and sodium polysulfide needed a double mol of hydrochloric acid. From this difference, quantity analysis of sodium polysulfide and sodium hydrogensulfide was carried out by solving a simultaneous equation. A standard sample containing 0.0050 mol of sodium disulfide was analysed. The quantities of sodium hydrogensulfide and sodium disulfide obtained were 0.0050 mol and 0.0049 mol, respectively. When sodium thiosulfate was present in this system, it was better to subtract the amount of sodium thiosulfate from the value of iodometry. A standard sample containing 0.0050 mol of sodium disulfide, sodium hydrogensulfide and sodium thiosulfate was analysed. The quantity of sodium disulfide obtained was 0.0048 mol and sodium hydrogensulfide was 0.0053 mol. In the second analysis, sodium sulfide and sodium hydrogensulfide were neutralized with 1N hydrochloric acid and a neutralization curve was made. Sodium hydrogensulfide showed a one step wave, but sodium sulfide showed a two step wave. The step wave in the higher position is denoted as the first wave and the lower position as the second wave. In the case of sodium sulfide, the first wave dissociates to sodium hydrogensulfide and sodium hydroxide, and the second wave dissociates to hydrogen sulfide and sodium hydroxide. So we could analyse the mixture of sodium hydrogensulfide and sodium sulfide from the neutralization curve. A standard sample containing 0.0055 mol of sodium hydrogensulfide and 0.0033 mol of sodium sulfide was analysed. The quantity of sodium hydrogensulfide obtained was 0.0056 mol and that of sulfide obtained was 0.0033 mol. These analytical values agreed with the calculated values. By mean of an application of this method, free alkali in sodium sulfide could also be analysed. In the case of sodium polysulfide, the average of the first wave and the second wave agreed with the concentration of sodium polysulfide. Quantity analysis of next three mixtures was established using the two methods, the first method was used for a and b, and the second method was used for a and c.
a: Mixture of sodium sulfide and sodium hydrogensulfide.
b: Mixture of sodium polysulfide and sodium hydrogensulfide.
c: Mixture of sodium sulfide and sodium hydroxide.

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In the study of sodium sulfide reduction, it was first necessary to find the quantity of α-nitronaphthalene and α-naphthylamine present. On the basis of this, the convertion of α-nitronaphthalene, the selectivity of α-naphthylamine, and the behavior of sodium sulfide reduction was sought. Quantitative analysis of α-nitronaphthalene and α-naphthylamine was done by gas chromatography. Separation was successful, but this reaction was hetrogeneous, consisting of sodium sulfide solution and oil of α-nitronaphthalene. The total weight of oils decreased. The total weight of oils must be measured to analyse the α-nitronaphthalene and α-naphthylamine in this reaction system, but as the sampling from this reaction mass must be continued to the end of the reaction, the weight of oils could not be measured. An attempt was made to analyse α-nitronaphthalene and α-naphthylamine by adding the standard material into this reaction system before reaction, analysing the sample which was picked up from this reaction mass by gas chromatography, measuring the area's ratio of chromatogram, and deciding from this ratio the quantity of α-nitronaphthalene and α-naphthylamine using a calibration curve. The standard material must comply to the next items.
(1) It must not react with sodium sulfide.
(2) Its gas chromatogram's peak must not be piled up on the peak of α-nitronaphthalene and α-naphthylamine.
(3) Its boiling point must be more than 100°C.
(4) It must not effect the reduction.
Naphthalene fit with these items, but stucks fast to condenser of the reacter during reaction. In this case the concentration of standard material was thought to be decreased. An attempt was made to solve this problem by adding a little benzene, using a water seal reacter having the sampling tube composed of teflon tube, with an inside diameter of 1 mm. An attempt was made to connect the needle to this tube and a sample was obtained with an injection syringe. By mean of this method the sample can be obtained any time and analysed by gas chromatography. To confirm this method, water, naphthalene, α-naphthylamine, α-nitronaphthalene and a little benzene was poured into a reaction vessel, and the sample taken up periodically. Each sample was analysed by gas chromatography and the quantity of α-nitronaphthalene or α-naphthylamine was measured. The reproducibility of the data was indicated by the values obtained in this experiment. The composition analysis of the reaction mass was established easily (during reaction) even though the reaction was heterogeneous, by mean of addition of standard material for the gas chromatography into the reaction system from the beginning and using the special reacter which control the concentration of the standard material always constant.

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A separate-reservoir-type diffusion cell was examined to produce air flow containing low concentration of organic vapor. For this purpose, benzene vapor-air mixtures at various levels were produced with the diffusion cell under various sets of the running conditions such as flow rate of air, size of a diffusion tube and temperature. The concentrations of benzene vapor in air flow were determined intermittently with a gas chromatograph from start of running the diffusion cell.
The steady-state concentrations thus obtained were processed into the geometric mean of the concentrations. Under all the sets, the geometric means of the steady-state concentrations of benzene vapor were in fairly good agreement with the calculated concentrations which were derived from a diffusion equation and flow rate of air. The agreement between the observed concentration and the calculated concentration was confirmed by producing seven kinds of dynamic vaporair mixtures with the diffusion cell. The standard deviation of the logarithmic concentrations was used as a scale of variation of the steady-state concentrations. The variation of the benzene vapor concentration in steady state was negligibly small with the diffusion tubes above 2 mm in diameter, but increased with the decreasing diameter below 2 mm. The variation was found proportional to volume of vapor space in a reservior flask and inversely to volume of a diffusion tube. The variation of the steady-state concentrations would be presumably caused by disturbance of vapor diffusion in the presence of small fluctuation of pressure and/or temperature.
In designing a separate-reservior-type diffusion cell, it was recommended to reduce the volume of vapor space in a reservior flask especially when a diffusion tube below 2 mm in diameter was used. In addition, it was also suggested to minimize fluctuation of pressure and/or temperature in the diffusion cell.

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Previously the authors developed spectrophotometric methods for the determination of boron in U₃O₈ and of tantalum with Methylene Blue. It was expected that rhenium as perrhenate, ReO₄^-, might give a color reaction with Methylene Blue. A preliminary test using dilute sulfuric acid solution gave a promising result. Later, the authors learned that Tarayan and Vartanyan (reference 4) described a method for the determination of rhenium with Methylene Blue. They extract Methylene Blue perrhenate into 1, 2-dichloro-ethane at pH 45 and measure the absorbance at 645 nm. The method described herein is different from their method and is more selective.
The neutral sample solution containing 215 μg of rhenium (VII) is transferred to a separatory funnel, 2 ml of 10 N sulfuric acid is added, and the solution is diluted to about 20 ml with water. Two ml of 0.001 M Methylene Blue is added, and the solution is shaken with 10.0 ml of 1, 2-dichloroethane for 1 min. The organic phase is transferred to another separatory funnel containing 5 ml of water and shaken for 1 min. (This washing removes excess of Methylene Blue and reduces the reagent blank value.) The organic phase is filtered through paper into a 1-cm cell. The absor-bance of the clear extract is measured at 658 nm against 1, 2-dichloroethane.
Beer's law is followed in the range 015 μg of rhenium per 10 ml of organic phase. The sensitivity is 0.0018 μg Re/cm² for an absorbance of 0.001. The apparent molar absorptivity is 1.0 × 10⁵. Six determinations of 10 μg rhenium gave a relative standard deviation of 0.6%. The extractability of rhenium under the conditions of determination was measured by using rhenium-188. The result is shown in Table I.
The result of the study on the interference is shown in Table II. Ten mg of boron, 100 mg of iron (III), 10 mg of molybdenum, 1 mg of tungsten, and 1 mg of tantalum do not interfere with the determination of 10 μg of rhenium. However, in the method of Tarayan and Vartanyan, it was reported that the upper limit of molybdenum which does not interfere is only 0.5 mg. The molar absorptivity of their method is 1.1 × 10⁵ at 645 nm.
The Methylene Blue method described herein is more sensitive and selective than the thiocyanate and α-furildioxime methods. The method appears to be as sensitive and selective as the Brilliant Green or Methyl Violet method.

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This paper describes a quick determination method of benzo(a)pyrene in yeast. This method consists of the following procedures; i) solvent extraction of aromatic compounds in yeast, ii) extraction of polynuclear hydrocarbons by liquid-liquid partitions, iii) isolation of benzo(a) pyrene by one-dimensional dual band thin layer chromatography, and iv) spectrofluo-rometrical determination of benzo(a)pyrene.
Aromatic compounds in yeast were extracted by benzene with the help of Soxhlet's extractor. The benzene extract was dried under reduced pressure at about 40°C, and the dried extract was dissolved in cyclohexane.
Polynuclear hydrocarbons in the cyclohexane solution were extracted selectively by a series of liquid-liquid partition of cyclohexane-dimethyl sulfoxide(DMSO), (DMSO + 20 vol% HCl; 1: 1, v/v)-cyclohexane, cyclohexane-70% H₂SO₄, cyclohexane-water, cyclohexane-5% NaOH, and cyclohexane-water. The cyclohexane solution thus obtained was evaporated to dryness under reduced pressure at low temperature (ca. 40°C). Polynuclear hydrocarbons in the residue were dissolved in ethyl ether and filtered. The filtrate was evaporated to small volume at low temperature (ca. 30°C) by rotary evaporator. The net amount of polynuclear hydrocarbons in the concentrated solution was applied repeatedly with intermittent drying onto the aluminum oxide G layer of thin-layer plate which was composed of aluminum oxide G layer and 26% acetylated cellulose layer. The plate was then inserted into a developing chamber with freshly prepared ethyl alcohol-ethyl ether-water (4: 4: 1, v/v). Development was continued until the front of the developer reached 10 cm from the layer boundary. After the development, the plate was withdrawn from the developing chamber and dried in a dark room. The plate was again developed to the 10 cm mark with methyl alcohol-ethyl ether-water (4: 4: 1, v/v). Benzo(a)pyrene thus separated was detected on ace-tylated cellulose layer as a narrow fluorescent spot under ultraviolet ray (365 nm). The benzo(a)pyrene spot was scraped off into a small centrifuge-tube, and benzo(a)pyrene in it was extracted with benzene by means of centrifugation. Benzo(a)pyrene in the benzene solution was analysed by spectrofluorometry.
We applied this analytical method to the quanti-tative determination of benzo(a)pyrene in seven kinds of yeasts and found the presence of benzo(a)pyrene in all yeasts tested. The contents of benzo(a)pyrene were very small and ranged from 0.32 ppb to 1.19 ppb.

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Determination of the mole ratio (F/P, where F and P are the amounts of formaldehyde and phenol, respectively) of resol type phenol-formaldehyde resins by pyrolysis gas chromatography was examined.
Samples of different F/P ratios (1.0, 1.5, 2.0, 2.5) were prepared by using NaOH as catalyst. Shimadzu GC-IC gas chromatograph was used with Shimadzu PYR-IA pyrolysis apparatus. Conditions of analysis were as follows: Column, Chromosorb W (80100 mesh) coated with dinonyl phthalate (20%), 3 mm in diameter, 1.5 m in length; column temperature, 120°C; detector temperature, 170°C; carrier gas, helium, 60 ml/min; pyrolysis temperature, 700, 750, 800, 850°C. About 5 mg of the sample was pyrolyzed in each run.
Although phenol, o-cresol, p-cresol, 2, 6-xylenol, 2, 4-xylenol and other compounds were detected in pyrolysate, the phenol, o-cresol, p-cresol were selected for the determination of the mole ratio. The ratios of o-cresol/phenol and p-cresol/phenol in the pyrolysate were determined, and the relationship between the above-mentioned ratios and the mole ratios was examined. The results were as follows.
(1) Compositions of the pyrolysates of uncured resins and the corresponding cured resins were almost the same. In the case of the cured resins, a stable base line was attainable immediately after air purge. How ever, in the case of uncured resins, the base line was disturbed for a long time by gradual emergence of methanol, water and unreacted phenol derived from the samples after air purge. This defect was excluded by the use of cured resins.
Thus, cured resins were suitable for the pyrolysis, and uncured resins were cured by heating at 135°C for 60 min. (JIS K 6802, 6909, the condition for determining non-volatile contents of liquid phenolic resins).
(2) At 850°C cresol in the pyrolysate decreased, and the standard deviation of F/P was large. At 700800°C, the standard deviations (as F/P) were 0.10.2, so that the determination of the mole ratios was satisfactory.
The main source of error was fluctuation of the pyrolysis temperature. In this respect, lower pyrolysis temperature is desirable. But, it should not be too low since at 700°C the experimental data indicated the delay of the pyrolysis. Accordingly 750°C was recommended for the pyrolysis temperature.
(3) This method was applied to the analysis of commercial samples of known mole ratio. It was observed that higher values were obtained for samples which were prepared by using alkaline earth hydroxides as catalysts. This fact suggests that the difference in the catalysts used in preparing samples can be detected by comparing the result of this method to that obtained by the I. R. or U. V. spectrophotometric analysis.

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A gas chromatographic method for the determination of CO-hemoglobin (CO-Hb) in human blood was investigated. A simple attachment for gas chromatograph, blood gas sampler (BGS-1A), in which CO was freed from CO-Hb with Van-Slyke reagent and directly transferred into gas chromatograph, was constructed. Performance of this BGS-1A, and analytical conditions were studied.
Co was released from CO-Hb and analysed by following conditions; blood sample was 20 μl, releasing reagent, 0.5 ml, reaction time in BGS-1A, 5 minutes, sampling time for GC, 30 sec, respectively. The setting of these sampling and reaction time must be kept precisely.
Blood clotting disturb the release of CO from samples and the determination should be started as soon as blood samples were taken out. If the samples are required to be stored over 200 hours, the samples must be kept in refregerators.
The content of CO-Hb in blood was calibrated from the saturated CO-Hb obtained by passing CO gas, or town gas through the blood for about 10 minutes.
A digital integrator is useful for prosessing gas chromatographic data, and this CO-Hb analysing system easily gave the content of CO-Hb in micro amounts of blood samples. (20 to 50 μl). The coefficient of variance of this method was calculated to be 0.024 when blood samples were taken 20 to 50 μl.
The higher level of CO-Hb in blood were obtained from the people, who were exposed in air pollution and smoking. It is interest that the smoking is one of the main factors to give higher content of blood CO-Hb.
In this study, it was proved that this gas chromatographic analysis of CO-Hb were superior to conventional Van-Slyke method and useful for the CO determination in micro amounts of blood samples.

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Atomic absorption spectrophotometric method for the determination of microamounts of silver, bismuth, copper, lead, manganese, nickel, palladium and magnesium in electrolytic gold and gold anode scrup was established. The recommended procedures are as follow. With the aid of heat, 1 g of sample was dissolved in 10 ml of dilute aquaregia and was evaporated to syrup state. It was dissolved in 10 ml of 6M hydrochloric acid, and the solution was transferred into a separtory funnel with 20 ml of 6M hydrochloric acid. This solution was extracted with 20 ml of a 1:1 volume mixture of methyl isobuthyl keton (MIBK) and isoamyl acetate and the aqueous phase was extracted with 10 ml of the mixed solvent again. According to this extraction separations, the residue of gold in the aqueous phase was about 0.013 mg.
The aqueous phase was transferred to a Pyrex beaker and was concentrated to one-third of its original volume. The solution was transferred into a separatory funnel using a small amount of pure water and was added 2 ml of 25 w/v% Rochell salt solution. The solution was then added aqueous ammonia untill pH range from 8 to 9 and was cooled to room temperature. The total volume of the solution was adjusted to 50 ml with pure water and it was permitted to stand for 2 to 3 minutes after an addition of 5 ml of 1 w/v% sodium diethyldithiocarbamate (DDTC) solution. The solution was then shaken with 10 ml of MIBK and the organic solvent was used to determine silver, bismuth, copper, lead, manganese, nickel and palladium by atomic absorption spectrophotometric method. The aqueous Phase was concentrated to about 5 ml. The solution was added dilute hydrochloric acid and was diluted with pure water untill the total volume became 25 ml. An adequate amount of this solution was used to determine magnesium by atomic absorption spectrophotometric method.
One sample can be analyzed within about 6 hours with the accuracy enough for practical usage. The sensitivities were, respectively, 0.01 of silver, 0.05 of bismuth, 0.02 of copper, 0.1 of lead, 0.02 of manganese, 0.02 of nickel, 0.05 of palladium and 0.005 of magnesium for the absorbance (μg/ml/%).

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2-(ο-Hydroxyphenyl)-benzoxazole (abbreviated to oxazole) forms a yellow colored 1:2 chelate with copper ion in acidic solution. Since the selectivity of the reaction with copper is high, studies on the gravimetric determination of copper in copper or aluminum alloys have been carried out. The copper oxazole chelate is dissolved into various kinds of organic solvents. The absorption curve of the chelate extracted into organic solvents shows an absorption maximum at 370 nm in carbon tetrachloride, benzene and toluene and at 365 nm in chloroform and methyl isobutyl ketone, whereas the reagent blank has an absorption maximum at 345 nm and a slight absorption at 370 nm against the respective organic solvents. In this paper, a highly sensitive and selective method of spectrophotometric determination of copper has been achieved by extraction of the chelate into carbon tetrachloride.
Since oxazole is only slightly souble in water, carrier precipitation of a minute amount of copper has also been investigated using oxazole as a collector organic reagent. A single precipitation of 0.01 g of oxazole in each case collects 9858% of copper in 1005000 ml of aqueous solution at pH 5.57.0. The relationship between the concentration of copper in the aqueous solution vs. the amount of copper coprecipitated with oxazole in equilibrium is quite similar as that obtained by solvent extraction. The distribution ratio of copper in this case has been caluculated to be 7.0×10⁵ (ml/g) at 20°C.
The precipitate of oxazole which collects coprecipitated copper is dissolved in hydrochloric acid, followed by carbon tetrachloride extraction and spectrophotometric determination of copper. These experiments were applied to the separation, concentration and determination of copper of an amount below 3 ppb in water samples.
The recommended procedure for the spectrophotometric determination of copper is as follows:
To a sample containing less than 40 μg of copper in a 100 ml separatory funnel, add 1 M acetic acid and 1 M sodium acetate solution to adjust pH 6.0, 1 ml of 0.5% ethanolic oxazole solution and 10.0 ml of carbon tetrachloride. Shake the liquids for 2 min, separate the organic phase and dried with anhydrous sodium sulfate. Measure the absorbance at 370 nm against the reagent blank as a reference. Beer's law is obeyed up to 40 μg of copper in 10 ml of the extract and the molar absorptivity is 2.5×104. A constant absorbance was obtained in the range 5.37.0 of pH, 50300 ml of the aqueous layers and 13 min of the shaking time.
Intreference by hydrolysis of iron(III) up to 20 ppm can be avoided by an addition of 5 ml of 10% ammonium tartrate solution per 100 ml of the aqueous solution. By an addition of 0.01 g of oxazole per 1000 ml sample solution, 88% of copper in the precipitate was recovered from 10005000 ml of water samples, followed by the determination of 0.230 μg of copper using the calibration curves obtained by the similar procedure.

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It was found that molybdenum reacts with tiron in the presence of zephiramine to give a yellow precipitate (molybdenum-tiron-zephiramine ternary complex) which has an absorption maximum at 390 nm when extracted into chloroform at pH 8.0. This spectrum of the complex may be used in the spectrophotometric determination of molybdenum, but such ions as iron (III), vanadium (V), and perchlorate interfere seriously with the determination. To prevent the interference of these ions, molybdenum was extracted into chloroform as α-benzoinoxime complex, which then reacted with tiron in the presence of zephiramine to form the molybdenum-tiron-zephiramine ternary complex in chloroform. This reaction was applied to the determination of molybdenum in iron and steel. The proposed procedure is as follows; 1.00.1 g of steel sample is decomposed with 20 ml of perchloric acid or aqua regia. After being cooled, the solution is transferred to a 100 ml volumetric flask and diluted to the mark with water. A 10 ml portion is transferred into a 100 ml separatory funnel, then 2 ml of 10% _L-ascorbic acid is added and made up to 20 ml with water. It is shaken with 10 ml of 0.2% α-benzoinoxime-chloroform for 3 min. After two phases have separated, a 5 ml portion of the organic phase is transfered to the second separatory funnel, and then 5 ml of phosphate buffer solution (pH 8.0), 2 ml of 0.8% tiron and 2 ml of 10^-2M zephiramine are added and shaken for 3 min and allowed to stand for 5 min. The lower organic phase is taken into a 50 ml stoppered conical flask. After dehydration with anhydrous sodium sulfate, the content is taken into a 1 cm cell and the absorbance is measured at 390 nm against chloroform.
Analytical results of the standard samples of iron and steel by this method were satisfactory. The addition of _L-ascorbic acid solution in extracting the complex did not affect the determination of molybdenum, but the coexistence of tungsten interfered with the determination, so in the case of tungsten-bearing steel, it was necessary to remove tungsten prior to the extraction of the molybdenum complex.

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Extraction of europium(III) complexes with thenoyltrifluoroacetone (TTA ; HA) in organic solvents has been investigated at 25°C by using europium 152+154 as the tracer from aqueous sodium perchlorate solution in which pH was kept at 2.0 to 4.5 and the ionic strength at 0.1. The chemical form of the extracted species into “inert” solvents was found to be EuA₃, while that into ethers was found to be solvated complexes, EuA₃·mS (where m=1, 2), with the solvent molecules (S) and thus a synergistic effect has been observed.
In order to examine the regularity in the distribution in these systems, the distribution ratios of europium (D_Eu) obtained at a definite pA have been correlated with the distribution coefficients of TTA (P_HA). The correlation between them at pA =5.50 has been found to be log D_Eu =2.9 log P_HA-5.82 for inert solvents and log D_Eu =3.3 log P_HA-3.48 for ethers except for a few solvents containing electron-drawing groups. The relation for inert solvents agrees with that expected from the solubility parameter concept, whereas the findings for ethers may be understandable by considering the role of the solvent molecules as donors in addition to the role as medium.
The extraction constants in the inert solvent system are expected to be independent of the kind of solvent under desirable conditions of the aqueous phase; the values of log K_ex have been found to be constant (log K_ex=-8.14±0.23).
The distribution ratios have been compared with those of scandium tris-TTA chelate that has a poor tendency to form adducts with donor solvents. In the inert solvent systems, the values of D_Eu are nearly proportional to those of D_Sc, log D_Eu (pA =5.50) = 1.1 log D_Sc (pA =8.00)-0.05; on the other hand, the distribution ratio is much enhanced with a donor solvent and a semi-empirical relation, log D_Eu(pA=5.50) =1.3 log D_Sc (pA =8.00) +2.98, has been found in the ether solvent systems. The distribution ratios have also been compared with those of uranyl bis-TTA chelate which trends to form a solvated complex; log D_Eu vs. log D_U plots are close to the straight line having a slope of 1.5 as expected.
Some regularities found in this study may be useful for the selection of a suitable solvent or for the estimation of distribution ratio.

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The adsorption of fourteen kinds of anions on a silica-alumina adsorbant(containing 2.70% aluminum and treated at 500°C) was studied by a batch method.
The adsorption capacity was decreased in the following sequence; Cr₂O₇^2-> EDTA^2- > Fe(CN)₆^3- >Fe(CN)₆^4- >SO₄^2- >MnO₄^- >CrO₄^2- > I^-> Br^-> SCN^- > Cl^- > F^- >NO₃^- >CN^-. This capacity was two to three times greater than silica gel treated at 300°C, while cation adsorptivity was found several tenths times less.
There found a proportional relationship between the capacity of adsorption and the molecular weight, ionic structure and valency of anion.
It was assumed that the availability of this adsorbant was restricted.

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In the ion selective electrode standard addition technique the error of determination caused by a change in the response slope was evaluated. It was pointed out that the modified Gran's plot shows a straight line even if the response slope is different from the true one and that an erroneous concentration may be obtained by the use of such a straight line. A simple method for the determination of the response slope is proposed as follows : An indifferent electrolyte is added to a sample solution, standard solution and diluent in order to bring them to the same ionic strength. The volume, v', of the diluent is added to the initial volume, V, of the sample solution in which the ion-selective electrode and reference electrode are immersed. Prior to the addition of the diluent, the cell potential of the sample solution is measured and denoted by E₁. The cell potential, E', after each addition of the diluent are measured and the response slope, k, is calculated by the following equation. E₁-E' =k·log V/ ( V+ v' ).
Then, the usual standard addition technique is applied to this diluted sample solution.

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It is often necessary that gas chromatographic columns are operated at such a high temperature as the use of them which is almost limited due to the high vapor pressure of the stationary liquid phase. In such cases, the stability of the retention volumes and of the separations are impaired during an operation for a long time by the decrease of the amount of the stationary liquid phase (bleeding). In order to reduce this difficulty, the GC which connected with a pre-mixed column in front of the column as shown in Figure 1 was designed. The carrier gas was saturated with the stationary liquid phase in the pre-mixed column kept at the same temperature as the column, and was introduced into the column.
The efficiency of the pre-mixed column, η, which is the ratio of changes in the retention times when the operation is conducted without and with pre-mixed column was derived theoretically as given in equation (6). The experimental results of isopropyl benzene of D. O. P. column at 160°C supported these considerations.

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Copper, lead and cadmium at the ppb level in high-purity tantalum metal are determined simultaneously by square-wave polarography after removal of tantalum by anion exchange. A 1-g sample is dissolved in a mixture of hydrofluoric and nitric acids in a Teflon beaker, and the solution (20 ml, 4 M in F^- and 0.5 M in NO₃^-) is introduced onto an anion-exchange column (Bio·Rad AG 1-X8, 100200 mesh, 10 mmφ × 150 mm, polyethylene tubing). Then 20 ml of the mixed acid (4 M HF +0.5 M HNO₃) is passed through the column. The effluent is evaporated to dryness and the residue is dissolved in 5 ml of the supporting electrolyte containing 0.5 M potassium chloride-0.1 M hydrochloric acid. The lower limits of determination are 0.05 ppm for copper, 0.1 ppm for lead, and 0.02 ppm for cadmium, and the precision is about 10% at the 0.2 ppm level. The time required for a determination is approximately 5 to 6 hours.

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The determination of small amounts of antimony by atomic absorption spectrometry combined the extraction with diethylammonium diethyldithiocarba-mate-xylene method was investigated. Antimony can be extracted quantitatively into the xylene from aqueous solutions containing sulfuric acid at less than 10 N.
The recovery of antimony by the extraction was found to be about 99% with a coefficient of variation of 2.3%. The calibration curve of this method shows good linearity in the concentration range of 030 ppm. The following sensitivities were obtained: 0.25 ppm for 1% absorption at 2175.9 Å; 0.6 ppm for 1% absorption at 2311.5 Å.
The present method was three times more sensitive than the direct method.

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A new method is proposed for the spectrophotometric determination of molybdenum(VI), which is based on the extraction of a molybdenum(VI)-indoferron chelate into chloroform in the presence of 1, 3-diphenylguanidinium (DPG) salt. The combining ratio of molybdenum(VI), indoferron, and DPG in the extracted species was shown to be 1: 2: 1. The extracted species had an absorption maximum at about 555 nm, and the maximum absorbance of the organic phase was obtained when the pH of the aqueous phase was between 1.5 and 2.1. Under the optimum, conditions, Beer's law was obeyed up to 67 μg molybdenum(VI) per 10 ml chloroform. The molar absorption coefficient of the extracted species is about 1×10⁴ cm² mol^-1 at 555 nm. Interfering cations such as iron(III), titanium(IV), and zirconium(IV) can be masked by addition of EDTA.

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When a metal complex is synthesized, the quantitative determination of metal elements has been made by several methods, such as spectrometry, complexometric titration and gravimetric methods. However, it is difficult to prepare clear solution for spectrometry or complexometric titration, if the metal complex has a low solubility. In such a case, the gravimetric method will be applicable instead, however, it consumes fairly large amount of the precious sample for each analysis. Therefore, quantitative analyses of the metal elements in metal complexes are not so easy and common as the organic elementary analyses.
For the quantitative analyses of metal elements, atomic absorption spectrometry is considered to be one of the best methods.
The authors attempted to employ atomic absorption spectrometry to the analyses of metal elements in metal complexes. In this paper, analyses of the glycine, oxine-5-sulfonic acid, and oxine chelates of Zn, Cu, Ni, and Co as well as the acetates of these metals were carried out under the conditions shown in Table II. From these investigations, measurements of water soluble metal complexes are recommended to be carried out in acidic medium, for example 0.1 N HCl solution. In the case of water insoluble complexes, it is better to dissolve them in either alcohol or other organic solvents, in which the complexes are soluble. The sample solutions of Cu, Ni, and Co complexes were made to be ca. 5 ppm in 0.1 N HCl and for Zn complexes ca. 0.5 ppm solution was used. The commercial standard solutions of Cu, Ni, Co, and Zn were diluted to make the working curves.
The advantages of the present method are as follows: (1) A very small amount of the sample is quite enough for the measurements, (2) the pretreatment is simple, (3) the sensitivity is high.
Therefore, the atomic absorption spectrometry is recommended to the quantitative analyses of metal elements in metal complexes.

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