BUNSEKI KAGAKU
Print ISSN : 0525-1931
Volume 22, Issue 3
Displaying 1-19 of 19 articles from this issue
  • Studies on analysis of electroceramics and its raw materials. III
    Kikuo WAKINO, Michihiro MURATA
    1973 Volume 22 Issue 3 Pages 255-259
    Published: March 05, 1973
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    The determination of uncombined barium oxide in barium titanate which is synthesized from barium carbonate and titanium dioxide at high temperatures can be a useful production test. Although the acetic acid technique is used as a chemical test, more rapid method is required. The authors have studied the X-ray diffraction method to satisfy the requirement.
    The crystal structure of barium titanate is tetragonal at the room temperature and the lattice constants are a =3.994Å and c =4.038Å. The X-ray diffraction peaks of the 002 and 200 reflections of a perfect crystal of barium titanate are separate from each other. However, if the crystal lattice of barium titanate is disordered during the synthesis, these diffraction peaks overlap each other.
    The “overlapping value” is defined in order to express quantitatively the degree of the overlapping of the 002 and 200 reflections (Fig. 1) and is used to estimate uncombined barium oxide. It is found that the “overlapping value” increases when the temperature of the synthesis decreases. There are many factors of the broadening of the diffraction peaks. It is supposed that in this experiment the main factor is the disorder of the crystal lattice of barium titanate. Because perfect crystals of barium titanate are insoluble in acetic acid, the amount of the titanium soluble in acetic acid in the specimen is determined in order to examine the supposition. The amount of the soluble titanium increases as the temperature of the synthesis decreases. Moreover, the disorder of the crystal lattice of barium titanate is examined by Hall's method of X-ray diffractometry. Both results show a similar tendency. Therefore, the content of barium atoms which are not in their normal position in the crystal frame can be identified as the content of uncombined barium oxide from the “overlapping value”.
    A linear relationship is observed between the “overlapping value” and the logarithm of the content of uncombined barium oxide which is determined by the acetic acid technique, when this content is between 0.3 and 10%. As the results of the experiment with the specimens which are synthesized by using the different kinds of titanium dioxide, the particle size of which are 0.3 and 7.5 μm respectively, it becomes clear that the particle size affects the “overlapping value” very seriously. However, the above-mentioned linear relationship holds for specimens prepared from the same titanium dioxide. Therefore, the calibration curve should be prepared by using the same titanium dioxide as that is used for samples.
    The results by the proposed method and the acetic acid technique agree well, and the proposed method is useful for the production test in the synthetic process. The detecting limit of this method is about 0.3%, which is not achieved by the ordinary X-ray diffraction method.
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  • Studies on relationships between thin-layer chromatography and column chromatography. IV
    Masao SUZUKI, Shoji TAKITANI
    1973 Volume 22 Issue 3 Pages 259-264
    Published: March 05, 1973
    Released on J-STAGE: February 16, 2010
    JOURNAL FREE ACCESS
    The relations between the migration rate (Kβ or K γ value) of the front formed in demixing process and the concentration of the more polar component in a developer were investigated in thin-layer (TLC) and dry column chromatography (DCC). These relations were applied to the choice of a more suitable composition of the developer.
    The following sets of adsorbent and developer were used in both TLC and DCC : 1. for separation of metallic ions (Cu2+, Ni2+ and Co2+) ; adsorbent, purified silica gel; developer, acetone-3N HCl system (acetone system) ; 2. for separation of Sudan IV, 2, 4-dinitroaniline, and quinine; adsorbent, silica gel H; developer, chloroform-1-butanol-diethylamine systems [chloroform system A. (98-M) : M : 2, and chloroform system B. (88- N) : 12 : N]. In TLC the sample solution was spotted on the thin-layer (thickness : 0.25 mm) at a distance (Y) of 2.5 cm from the edge of the plate and developed ascendingly. The distance (X) between the immersion line and the edge of the plate and that (Z) between the solvent front (α-front) and the edge of the plate were 1 cm and 12.5 cm, respectively. A column of 1 cm (inner diameter) × 10 or 12 cm (height) was used in DCC. After the development the spots or zones of the sample and the demixing lines were detected by ultra-violet ray (3600 A) or by applying appropriate reagents. Each component of the eluate in DCC with the acetone system was determined by using acid-base titration and iodometry (Fig. 2).
    Co2+ traveled always nearer to the β-front, Cu2+ in the α-zone, and Ni2+ in the β-zone. 2, 4-Dinitroaniline and quinine traveled on the β- and γ-front, respectively, and Sudan IV in the α-zone. Because of the phenomenon of chromatographic demixing of developer, two fronts (α- and β-front) were observed in the acetone system, and three fronts (α-, β- and γ-front) in the chloroform systems. In both TLC and DCC, the logarithmic relations between Kβ (or Kγ) value and the concentration (mole per cent, CM) of the more polar component in the developer were shown, and the equation based the adsorption isotherm of Freundlich [log (1/K-1) =κ-ξ log CM… ( 1 ), where κ and ξ are constants] was held for K=Kβ and K=Kγ (Fig. 1, 4, 5, 6). The constants of equation ( 1 ) were determined experimentally; in TLC, the following constants were obtained : κ=-0.03, ξ=0.68 (acetone system) ; κ=0.92, ξ=1.16 (chloroform system A) ; and κ=0. 75, ξ=0.98 (chloroform system B) (Fig. 1, 4, 5). While in DCC with the chloroform system B, κ=0. 70 and ξ=1.00 (Fig. 6).
    The optimum composition of the developer for separation of the samples (Cu2+-Co2+, Sudan IV-2, 4-dinitroaniline, 2, 4-dinitroaniline-quinine) was calculated by using the chromatographic data of each sample and equation ( 1 ) as follows. The optimum Kβ (Kγ) value in order to separate the two samples was calculated by means of equation ( 2 ) :
    Kβ(or γ)=(Rf±ΔRf)(Z-Y)+(Y-X)/(Z-X)…(2)
    where Rf is the Rf value of the sample on the β- or γ-front, and ΔRf the difference of Rf value which is needed in order to separate the two samples.
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  • Hideo TOMIOKA, Kuniko TERAJIMA
    1973 Volume 22 Issue 3 Pages 264-269
    Published: March 05, 1973
    Released on J-STAGE: February 16, 2010
    JOURNAL FREE ACCESS
    The writers found, that the reddish brown palladium-bismuthiol II complex can be extracted into certain organic solvents and an absorptiometric method for the determination of small amounts of palladium in conjunction with extraction of the complex is possible.
    The extraction of the complex from hydrochloric, sulfuric, nitric, phosphoric, and perchloric acid has been investigated and that from 0.5 to 1.0N perchloric acid with tributyl phosphate has been found to give the most stable color.
    The complex could be quantitatively extracted by tributyl phosphate from perchloric acid solution of an acidity ranging from 0.5 to 1.0N but it could not be extracted with the same solvent from alkali solution. The molar extinction coefficient of the complex in tributyl phosphate at 450 nm was 4.60 × 103, and the sensitivity according to Sandell's expression was 0.023 μg/cm2. Beer's law was obeyed up to 15 μg/ml of palladium for the absorbance measured at 450 nm. It was confirmed, by the method of continuous variations, that the ratio of palladium to bismuthiol II in the complex in tributyl phosphate was 1 to 2.
    On the basis of these observations, the writers propose the following procedure :
    A 50 ml aqueous solution which contains up to 150 μg of palladium and 0.75N perchloric acid is prepared. It is shaken vigorously for 90 sec with 10 ml of 0.05% tributyl phosphate solution of bismuthiol II and the absorbance of the extract is measured at 450 nm.
    Though copper (II), bismuth (III), iron (III), osmium (VIII), selenium (IV) etc. interfere with the determination of palladium, the interference except with the last two can be eliminated if the organic phase is washed with 50 ml of sodium hydroxide (about 0.16 N) after the extraction.
    The osmium-bismuthiol II complex which is green in both acid and alkali media can be extracted with tributyl phosphate. Since the complex in tributyl phosphate has an absorption maximum at about 780 nm under the conditions employed for the determination of palladium, palladium and osmium can be determined simultaneously by extracting their bismuthiol II complexes with tributyl phosphate.
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  • Satoru SAKURABA
    1973 Volume 22 Issue 3 Pages 270-275
    Published: March 05, 1973
    Released on J-STAGE: February 16, 2010
    JOURNAL FREE ACCESS
    Gallein reacted with molybdenum (VI) to form water soluble various complex in the presence of excessive species of quaternary ammonium salt. Gallein reacts with molybdenum (VI) in the presence of cetylpyridinium chloride (CPC) to form a water soluble, red-purple chelate. The absorption maximum was at 590 nm, and the absorbance was constant over the pH range from 1.0 to 2.7 adjusted with HCl buffer solution. The complex has a composition of 1 : 1.5 in the excessive CPC.
    The molar absorptivity is 4.9 × 104 at 590 nm and the sensitivity is 0.0020 μg Mo/ml for an absorbance of 0.001.
    The effect of diverse ion on the absorbance of the complex was examined. Antimony, tin, vanadium, and tungsten must be avoided. Antimony could be masked by an addition of 0.05M EDTA. Vanadium could be masked by an addition of 0.05M EDTA and 0.1 g KF.
    The ternary complex system between molybdenum (VI), gallein and zephiramine formed a water soluble blue chelate. The absorption maximum was at 620 nm, and the absorbance was constant over the pH range from 1.0 to 1.5 adjusted with buffer solution. The complex has a composition of 1 : 2 in the excessive zephiramine.
    The molar absorptivity is 5.2 × 104 at 620 nm and sensitivity is 0.00185 μg Mo/ml for an absorbance of 0.001.
    The effect of diverse ions on the absorbance of the complexes was examined. Tin, chromium, titanium, and silver must be avoided.
    The both complex were proposed for the spectrophotometric determination of microgram amounts of molybdenum. The calibration curve at 590 nm (in the presence of CPC), and at 620 nm (in the presence of zephiramine) was quite linear for 03.5 μg/ ml molybdenum.
    The recommended analytical procedure was as follows. To a 25 ml volumetric flask was added the sample solution containing less than 88 μg of molybdenum (VI) /25 ml. Then 7 ml of HCl (pH 1) solution, 2 ml of 1 × 10 -3M ethanolic gallein solution, and 2.5 ml of 2.0 × 10 -2M CPC or zephiramine solution were added to sample solution. The whole was made up to the mark with distilled water.
    After it was allowed to stand for 20 minutes at 25°C, the absorbance was measured at 590 nm or at 620 nm against the reagent blank.
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  • Junji MORIKAWA, Kazuei TAKASE, Ryuzaburo OSAWA
    1973 Volume 22 Issue 3 Pages 275-279
    Published: March 05, 1973
    Released on J-STAGE: May 07, 2010
    JOURNAL FREE ACCESS
    Transferrin, an iron binding protein, facilitates iron metabolism by transfering iron in serum. Its unsaturated iron binding capacity has been measured by deducting serum iron (SI) from total iron binding capacity (TIBC). For TIBC measurements in the alkaline zone, the procedure has been to add an excess quantity of iron in order to saturate transferrin with iron, and acidify it after removing the surplus iron with a suitable adsorbent. The iron is then released from transferrin in order to make a colorimetric determination. There are also other procedures which are based on direct radio isotope measurements in which transferrin is saturated with a known quantity of 59Fe and the surplus is adsorbed in a resin sponge in order to determine the intensity of radioactivity. However, in these methods there were difficulties in that the procedures for removing the surplus iron were complicated, and that special apparatus was necessary for RI. Therefore, ways to make use of transferrin's binding capacity in the alkaline zone have been studied. Transferrin can be saturated with a known quantity of exess iron. The remaining unbound surplus iron can then be fixed quanttaitively so as to obtain the unsaturated iron binding capacity (UIBC) value. As iron ion solution is unstable in the alkaline zone, it is stabilized as nitrilotriacetic acid (NTA) -iron chelates. The remaining surplus iron, viz NTA-iron chelates, is measured by using bathophenanthroline sulfonic acid (BPT).
    Iron and BPT chelates have maximum absorbance at a wave length of 535 nm and iron, following Beer's law, up to 600 μg/dl. Under experimental conditions, it has been confirmed that there is a correlation between the binding capacity of transferrin with iron and the stability of iron chelates with NTA, or BPT; (transferrin-BPT) NTA in the range of pH 8.48.7. The error of this method is approximately 15 μg/dl when the concentration of bilirubin is 10 mg/dl and the mean recovery is 94.4%. Results obtained by this method can be correlated well with the results of the adsorbent methods, obtained by calculation from TIBC (light MgCO3, Amberlite IRA-410 resin adsorption). Thus, UIBC can be measured simply, quickly and accurately: the coefficient of variation is 1.3% with a mean of 190 μg/dl, (obtained by application to human serum measurement). Relatively small amounts of serum samples can be analyzed by this method, and thus it is also suitable for routine clinical determination.
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  • Tsutomu FUKASAWA, Takeshi YAMANE, Takeshi YAMAZAKI
    1973 Volume 22 Issue 3 Pages 280-284
    Published: March 05, 1973
    Released on J-STAGE: February 16, 2010
    JOURNAL FREE ACCESS
    A rapid and sensitive method has been developed for the determination of manganese down to several ppb in high-purity sulfur. The method is based on the separation and concentration of manganese in sulfur by combustion in air stream followed by the kinetic determination of manganese as described in the previous paper.
    The procedure can be outlined as follows.
    Weigh the ground sample(containing 5 to 100 ng of manganese) into a quartz combustion boat, and carefully charge it into the combustion furnace, which is previously kept at 250±5°C. Connect up the apparatus as shown in Fig. 1. Introduce the pretreated air of room temperature into the furnace at rate of about 250 ml per min and maintain this conditions for about 30 min (for 1 to 2 g of sample).
    Combustion of the sample in higher flow rate of air and higher furnace temperature is unsuitable because the lower manganese value is obtained in these conditions.
    On the other hand combustion in lower flow rate and lower temperature is time-consuming.
    After the completion of combustion, remove the boat and cool it to room temperature. Add 0.5 ml of 6M hydrochloric acid, then heat gently and evaporate to dryness. At this time the temperature should not be over 160°C. Dissolve the residue in 2.6 ml of an acetate buffer solution(10 M acetic acid solution: 2 M sodium acetate solution=1.6 : 1.0) and transfer the obtained solution to a test tube (25 ml) with a ground glass stopper with water, and then warm to 31°C in the thermostated water bath.
    Add 0.4 ml of 2.16 × 10-4 M Malachite Green solution and 0.5 ml of 1.7 × 10-2 M potassium periodate solution, shake and transfer a portion of this solution into the photometer cell (1 cm), and measure the absorbance at 615 nm.
    From the logarithmic plot of absorbance (a-x) against reaction time t, reaction rate constant k is obtained and manganese content is calculated from the previously prepared calibration curve (namely, relationship between manganese concentration and reaction rate constant k with standard manganese solution).
    The proposed method allows determination of manganese as low as 5 ppb for 1 g sample. The time required for an analysis is about 80 min.
    The estimated standard deviations were 1.9 and 3.2 ppb for the samples containing 16 and 55 ppb of manganese, respectively.
    The conditions of combustion and others are also studied in detail.
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  • Thin-layer chromatography on precoated adsorbents fixed with fused glass. VI
    Tamotsu OKUMURA, Tetsuro KADONO
    1973 Volume 22 Issue 3 Pages 285-291
    Published: March 05, 1973
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    In a previous paper we reported the preparation of a new plate for thin-layer chromatography (TLC), which was made from silica gel-fused glass powder mixtures. Throughout the previous work the homogeneous soda-lime glass was used as both binder and base plate purposes.
    In the present paper, we reported the success in the welding of the silica gel or alumina for TLC use over several kinds of glass or metal base plate using several kinds of sintered glass as binder. As shown in Table I, these materials are very much different each other in their expansion coefficient (α).
    Using these silica gel and alumina sintered plates, thin-layer chromatographic separation of the following test mixtures was performed: azo dyes (Indophenol, Sudan Red G and Butter Yellow for silica gel sintered plate, and azobenzene, Sudan Yellow and p-aminoazo-benzene for alumina sintered plate), estrogens (estriol, estradiol and estrone for silica gel sintered plate) and alkaloids (quinine, codeine, brucine and thebaine for alumina sintered plate). All these plates are heat-stable, and those with glass base plate acid-resistant and, moreover, can be repeatedly used by soaking the chromatograms into cleaning solutions such as chromic acid mixture or concentrated nitric acid. As shown in Table VII, the silica gel quartz sintered plate has, among others, a very superior reproducibility of separation.
    The welding mechanism of these silica gel and alumina sintered plates was clarified by means of scanning electron microscopic method. Although the heterogeneous systems made from such a silica gel or alumina(α=5.4 and 8.0 × 10-7 cm/cm/°C) as adsorbent, lead silicate or soda-lime powdered glass (α=95 and 92 × 10-7 cm/cm/°C) as binder, and quartz or aluminum (α =5.5 and 207 × 10-7 cm/cm/°C) as base plate are not expected to weld well each other, the welding among these three materials did occur. As shown in photo. 12 (surface view of the plate) and photo. 35 (cross sectional view of the plate) obtained by the scanning electron microscopic method, the adsorbents are fixed among the three dimensional space formed by the sintered powdered glass and the glass or metal base plates without loss of their original surface structures. Thus, the sintered powdered glass does play a role of binder fixing adsorbents on the surface of the glass or metal plates even when these three materials are heterogeneous and very much different each other in their physical properties.
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  • Kazuyoshi TAKIYAMA, Terumi KOZEN
    1973 Volume 22 Issue 3 Pages 291-301
    Published: March 05, 1973
    Released on J-STAGE: February 16, 2010
    JOURNAL FREE ACCESS
    Cadmium and zinc 8-hydroxyquinolates precipitate quantitatively in the range of pH above 5.4 and 4.58 respectively and they are determined as Me(C9H6-NO)2 by drying at 130°C. These compounds were prepared as pure and easily filterable precipitates by the precipitation from homogeneous solution using 8-acetoxyquinoline. The quantitative treatment of cadmium 8-hydroxyquinolate precipitated from homogeneous solution, the solubilities and the properties of the crystals of cadmium and zinc 8-hydroxyquinolates are discussed in this paper.
    An aqueous solution of 200 ml containing 1 to 30 mg of cadmium was added by 8-acetoxyquinoline solution in acetone at pH 7 to 9 and the solution was kept over night at room temperature. The precipitate was filtered and weighed after drying at 130°C for the gravimetric determination.
    The concentration of saturated solution of cadmium and zinc 8-hydroxyquinolates in the pure water and in various buffer solutions was measured by the atomic absorption method and the results are shown in Table IV. The solubility products of cadmium and zinc 8-hydroxyquinolates were calculated as 10-26.24 and 10-27.68, respectively. The solubility curves of various species of 8-hydroxyquinolate (e. g. [Cd2+], [CdQ+], [CdQ2]) at various pHs and at various concentrations of 8-hydroxyquinoline are shown in Fig. 1 to 3.
    The induction periods for the precipitation at various initial concentrations were measured and the crystalline nuclei of the precipitates of cadmium and zinc 8-hydroxyquinolates were recognized to be composed of 4 molecules by applying equations 16 and 17.
    The crystal structure of zinc 8-hydroxyquinolate was analyzed by Merritt etc. and it belonged to the monoclinic system. The each particle of this precipitate was long hexagonal lamella and the long and short axes were b- and c-axes and a-axis was perpendicular to the lamellar crystal as shown in Fig. 6 and 7.
    Cadmium 8-hydroxyquinolate precipitated from homogeneous solution has the dimorphism. It deposited as the precipitate containing long hexagonal lamellar crystals in the acidic medium, but in the basic medium it deposited as the precipitate composed of needle crystals at first and these needle crystals changed gradually to long hexagonal lamellar crystals in the mother liquor as shown in Fig. 8 and 9. It seems that the transformation occurred by the dissolution of the needle crystals and the deposition as the stable hexagonal crystals as shown in Fig. 10. The crystal structure of these crystals were analyzed. The needle crystal belonged to the tetragonal system whose lattice constants were such as a0=b0=10.3 and c0= 13.9 and the long axis was c-axis as shown in Fig. 11. The long hexagonal lamellar crystal belonged to the monoclinic system whose lattice constants were such as a0= 13.74, b0= 5.28, c0=11.36 and β=116°18'. This crystal was the isomorphous with zinc 8-hydroxyquinolate as shown in Fig. 12.
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  • Kazuyoshi TAKIYAMA, Terumi KOZEN
    1973 Volume 22 Issue 3 Pages 301-306
    Published: March 05, 1973
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    Zinc and cadmium 8-hydroxyquinolates have the same chemical composition, M(C9H6NO)2·2H2O, and precipitate quantitatively at pH values higher than 5 and 5.5, respectively. The solubility products of zinc and cadmium 8-hydroxyquinolates are 10-27.68 and 10-26.24, respectively. The precipitated particles of zinc 8-hydroxyquinolate are long hexagonal lamellar crystals of the monoclinic system. Cadmium 8-hydroxyquinolate in acid medium deposits as particles having the same morphological and crystallographic properites as zinc 8-hydroxyquinolate, but it precipitates from basic medium initially as needle crystals belonging to the tetragonal system which change to long hexagonal lamellar crystals isomorphous with zinc 8-hydroxyquinolate. The ionic radii of zinc and cadmium are 0.83 Å and 1.03 Å, respectively. The coprecipitation of zinc and cadmium 8-hydroxyquinolates, whose properies are almost the same as described above, are discussed in this paper.
    Each 5 ml of 0.01 M zinc and cadmium solutions were mixed, and the pH of the solution was adjusted at 5.6 to 11.6. 8-acetoxyquinoline solution in acetone was added to the solution. The final volume of the solution was adjusted to 200 ml, and it was stirred at 25°C. The precipitate of 8-hydroxyquinolate produced was filtered and analyzed polarographycally after being dissolved in hydrochloric acid.
    The results of coprecipitation are shown in Fig. 1. The coprecipitation curves were different at different pH's and the distribution coefficient reached the maximum value of unity at pH 8.1 as shown in Fig. 2.
    Around pH 5.5 zinc 8-hydroxyquinolate precipitated quantitatively, but cadmium 8-hydroxyquinolate did not, and in acidic medium zinc 8-hydroxyquinolate precipitated prior to cadmium 8-hydroxyquinolate. Around pH 8.1 the solubilities of both zinc and cadmium compounds were practically the same and both compounds precipitated at the same rate. At higher pH cadmium 8-hydroxyquinolate had a tendency to deposit as needle crystals which dissolved and transformed to hexagonal lamellar particles. Thus cadmium 8-hydroxyquinolate seems to be more soluble than zinc compound at the initial stage of the precipitation at higher pH. Therefore, zinc 8-hydroxyquinolate precipitated prior to cadmium compound at higher pH region.
    The particles prepared by the coprecipitation at various pH's were similarly long hexagonal lamellar crystals as shown in Fig. 4. At pH 9 the needle crystals of cadmium 8-hydroxyquinolate, which would deposit in a reacting solution containing only cadmium, did not appear in the case of coprecipitation. During the coprecipitation of 8-hydroxyquinolates at pH 9 zinc precipitated prior to cadmium and cadmium 8-hydroxyquinolate deposited as hexagonal lamellar particles with zinc compound. Cadmium 8-hydroxyquinolate was induced by the monoclinic zinc compound to form hexagonal particles and the produced particles seem to be solid solutions of zinc and cadmium 8-hydroxyquinolates.
    X-Ray diffraction analysis showed that the particles produced by the coprecipitation at various pH's were the solid solutions.
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  • Yoshihito SUZUKI, Yutaka YAMAZAKI, Tsugio TAKEUCHI
    1973 Volume 22 Issue 3 Pages 306-311
    Published: March 05, 1973
    Released on J-STAGE: February 16, 2010
    JOURNAL FREE ACCESS
    In column chromatography, the following Martin equation is well satisfied: 1/Rf=1+K (Ls/Lm), where, Ls/Lm is the volume ratio of stationary phase to mobile phase, and K is the partition coefficient of solute. On the other hand, the above relation has not been fully examined in thin-layer chromatography (TLC) because of the difficulty in measurements of the values of Ls and Lm.
    In the present work, a series of TLC experiments has been carried out in order to examine the applicability of the Martin equation in TLC. The values of Ls and Lm were determined gravimetrically by using mechanically strong “sintered plates”, which were prepared by sintering the mixture of glass powder and adsorbent (silica gel or kieselguhr) on glass plates at 450 to 750°C.
    The outline of the TLC procedure was as follows. The silica gel sintered plates or the kieselguhr sintered plates were heated at 110°C for 1 hr; after being cooled in a desiccator they were coated with liquid polyethylene glycol(PEG) of various molecular weights(62600) by dipping the plates into PEG-acetone solutions. Samples of 2, 4-dinitrophenylhydrazones of aromatic aldehydes were applied on the plates and developed ascendingly with isopropyl ether. The spots were detected by spraying 5% KOH-ethanol solution.
    Rf values decreased with the increase in PEG amount, and plots of 1/Rf against Ls were found to be linear.
    The values of Kt, the partition coefficient of the sample solutes between PEG and isopropyl ether calculated from Ls, Lm and Rf values in TLC experiments, were only 1155% of the values of K, the partition coefficient measured by the batch method.
    The difference between the values Kt and K can be explained by (1) the alteration of the solubility of PEG by mutual interaction of PEG and the adsorbent, and (2) incomplete partition equilibrium of the sample solutes between PEG and the mobile phases.
    For practical use the effectiveness of a stationary phase can be estimated from the value of θ (=Kt/K), which is tabulated in Table V. As the values of θ increased with the molecular weight of PEG, it can be realized that the use of PEG of large molecular weight, such as PEG 400 or 600, is effective in partition TLC.
    In the course of the investigation, the authors also found out that adsorption sites in adsorbent were destructed by coating with PEG. In TLC with silica gel adsorbent, for example, its adsorption chromatographic behavior disappeared gradually and partition chromatographic behavior appeared with the increase of the amount of PEG coated.
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  • Application of controlled potential coulometry to the automatic recording of liquid chromatography. V
    Yoshinori TAKATA, Yoshijiro ARIKAWA
    1973 Volume 22 Issue 3 Pages 312-318
    Published: March 05, 1973
    Released on J-STAGE: February 16, 2010
    JOURNAL FREE ACCESS
    A new method of detection based on controlled potential coulometry for liquid chromatography has been developed. This paper presents an improvement of the electrolytic flow cell and a method for detecting metal ions without interference of the dissolved oxygen in the column effluent.
    In principle, the technique depends on introducing the column effluent into a cell where electrochemical reaction of almost all of the constituents take place at a working electrode of a constant potential. The potential is selected so that it is sufficient to electrolyse the ions to be determined but insufficient to electrolyse the eluate substrate. The electrolytic current measured is recorded on a recorder and the concentrations or the amounts of the constituents are calculated by Faraday's law.
    Three types of the cell were designed and tested.Each of them consists of a working electrode of large surface area placed between two auxiliary electrodes. The working electrode and the auxiliary electrodes are separated by diaphragms of ion-exchange membrane. The working electrode is made of carbon-cloth and the auxiliary electrodes are silver-silver iodide wire netting of about 40 mesh. The electrodes are tightly fitted in openings of silicone rubber plates, which are arranged and bound with clamping bolts into a liquid-tight cell. One of these cells has a speed of response of less than 1 second and can be used in the flow rate of the effluent as large as 6 ml/min with the electrolytic efficiency of more than 99.5%. It has also a high sensitivity and is suitable for the high speed analysis in liquid chromatography.
    The electrochemical reaction applied to the detection of a metal ion, Mn+, was as follows:
    [Hg-DTPA]3-+Mn++2e
    →[M-DTPA](5-n)-+Hg
    Ag+, Au(III), Bi3+, Cd2+, Co2+, Cu2+, Fe2+, Fe3+, Hg2+, Mn2+, Ni2+, Pb2+, VO2+, Zn2+, and ions of alkaline earth metals and rare earth metals were detected quantitatively with the electrolytic cell. Aluminum and antimony ions were also detected but not quantitatively.
    The method was applied successfully to the detection of alkaline earth metal ions, Mg2+, Ca2+, Sr2+ and Ba2+ separated by cation exchange chromatography.
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  • Tsuguo SAWAYA, Hajime ISHII, Tsugikatsu ODASHIMA
    1973 Volume 22 Issue 3 Pages 318-322
    Published: March 05, 1973
    Released on J-STAGE: February 16, 2010
    JOURNAL FREE ACCESS
    In acid and neutral solutions, Brilliant Green(C. I. 42040) which is in the R+ form, has been used to determine antimony, gold, rhenium and other metals.
    A method has been developed for the spectrophotometric determination of microgram amounts of mercury, after extraction of mercury(II) from an aqueous solution into benzene with Brilliant Green (R+formed in acid solution) in the presence of potassium iodide.
    Various factors such as pH, concentration of potassium iodide and Brilliant Green, volume ratio of two phases, shaking time, diverse ions, etc. have been studied, and the optimum conditions for the determination of mercury have been examined.
    Mercury(II) in the presence of potassium iodide was found to react with Brilliant Green to form tetra iodomercurate-Brilliant Green ion-association complex, which can be extracted quantitatively into benzene in pH region between 0.7 and 1.5. The complex extracted was stable and had an absorption maximum at 640 nm. The molar ratio of mercury to Brilliant Green in the complex has been confirmed to be 1 : 2 by the continuous variation. The recommended procedures are as follows.
    Place an aliquot of standard mercuric nitrate solution (or of sample solution), containing up to 20 μg of mercury(II), in a 50 ml separation funnel, and make the volume up to 21 ml with water. Add 3 ml of 0.1 M potassium iodide solution, 3 ml of 10-3M Brilliant Green solution, the pH of the solution is adjusted to 0.71.5 with 1.8 N sulfuric acid, and then make the final volume of the aqueous phase 30 ml. Extract the complex with 10.0 ml of benzene by shaking the two phases for 5 minutes. After the phases separate, transfer the organic layer into a stoppered glass bottle containing sodium sulfate, and then transfer into a 1 cm cell and measure the absorbance at 640 nm against the reagent blank.
    Beer's law was obeyed over the range 0 to 20 μg of mercury. The molar ratio absorptivity of the complex at 640 nm was 1.0 × 105 and the sensitivity for log(I0/I) =0.001 was 1.7 × 10-3 μgHg/cm2. Perchlorate, thiocyanate and Fe(III) interfered with the determination seriously.
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  • Tomozo KOH
    1973 Volume 22 Issue 3 Pages 322-328
    Published: March 05, 1973
    Released on J-STAGE: February 16, 2010
    JOURNAL FREE ACCESS
    In the previous paper, a spectrophotometric method for the determination of ultramicro amounts of polythionate when only one of tetra-, penta- or hexathionate is present has been described; the method is based on the formation of thiocyanate equivalent to the polythionates and on the extraction of an ion-pair between Methylene Blue and thiocyanate with an organic solvent. In the present paper, a spectrophotometric method for the determination of thiosulfate has been devised as a fundamental experiment for the determination of polythionates when two species of them (tetra-, penta- and hexathionate) in amounts such as 10-6 M coexist. The method is based on the formation of thiocyanate from thiosulfate by the following reaction in the presence of copper(II):
    S2O32-+CN-=SO32-+SCN-
    and on the extraction of an ion-pair between Methylene Blue and thiocyanate with 1, 2-dichloroethane. The analytical procedure is as follows.
    Add 10.0 ml of sample solution, 0.5 ml of 0.13 M sodium carbonate solution, 2.0 ml of 0.05 M potassium cyanide solution, and 1.0 ml of 0.06 M copper(II) sulfate solution to an approximately 50 mlseparatory funnel; the pH of the solution is thereby brought to 7.9. Then, shake the mixture vigorously by hand and leave the reacted solution for 20 minutes in order to convert the thiosulfate quantitatively to thiocyanate. To this mixture, add 1.5 ml of 0.2 M ammonium iron (III) sulfate in 0.33 N sulfuric acid solution, 1.2 ml of 2.0 × 10-3 M Methylene Blue solution and 10.0 ml of 1, 2-dichloroethane. Shake the solutions for about 3 minutes to extract the ion-pair formed between Methylene Blue and thiocyanate. When the two layers have separated, transfer the organic layer to an approximately 15 ml glass tube equipped with a glass stopper, and add some amount of anhydrous sodium sulfate. Shake the mixture vigorously by hand until the solution becomes transparent, and measure the absorbance of the clear solution against dichloroethane at 657 nm.
    The effects of such factors as pH, reaction time, amounts of cyanide and copper(II) and way of shaking, on the cyanolysis of thiosulfate in amounts such as 10-6 M were discussed, and the conditions for thiosulfate to be completely converted into thiocyanate were established. The serious interference of copper(II) used as the catalyst, which may be caused by the formation of cyano-copper(I) complex anion, could be removed by an addition of iron(III). The method is suitable for the determination of 2.5 × 10 -712 × 10 -6 M thiosulfate.
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  • Hirokazu HANAOKA, Sho KAWAMATA, Eiichi ASADA
    1973 Volume 22 Issue 3 Pages 328-334
    Published: March 05, 1973
    Released on J-STAGE: February 16, 2010
    JOURNAL FREE ACCESS
    The applicability of the X-ray emission spectrography to the spot analysis have been pointed out and actively studied. However, the discussions have been concentrated mostly on the analysis for heavy elements and not for light elements. Here we studied the fundamental considerations for the analysis of light elements and, as one of the applications, determined the quantity of sulfur in heavy oil and of aluminum in the cement.
    In the spot analysis, the fundamental equation {eq. (1)} for the intensity of fluorescent X-rays can be approximated to eq. (2), which is the basic relation for the spot analysis, where the element to be analyzed can be determined not being suffered from other coexisting elements. However, it is found from the calculation of absorption coefficients that this approximation holds for the heavy elements, but not for the light elements. For the latter case, it is found that the equation {eq. (3)} of the intensity for the specimen with infinite thickness can be rather applied, because the mass absorption coefficient of filter paper for soft X-rays relatively increases as compared with the case of heavy elements (Table I). In this case, it can be calculated that, when the quantity of the droplet is very little, the denominator in eq. (3) can be attributed mostly from filter paper but not from the solute under the normal concentration. So we were convinced, that the spot analysis can be a practical and convenient method where X-ray intensity of the element to be analyzed is hardly suffered from other co-existing elements for the light elements as well as heavy elements.
    There might be the possibility that the sulfur-contained compounds would be vaporized or decomposed when the X-rays is applied to heavy oil in the vacuum, and so we studied changes of SKα intensity with irradiation time, for various conditions (Figs. 14). Moreover, the SKα intensity variation, which is due to the difference of the spot quantity, (Figs. 5 & 6) and the error at the measurements (Table II) were investigated.
    From those observations, we have fixed the analysis procedures as follows:
    At first, we make the specimen pieces in the sequential procedures, where we add xylene to the heavy oil sample in each same amount, obtain the quantity of 10 μl from thus obtained solution and then spot on the No. 7 filter paper. We prepare three specimen pieces for the same solution. The measurement of the X-ray intensity is done twice for each specimen piece and so we obtain the value as its average. The standard deviation of the error from the chemical analysis is 0.04% (Table III).
    Using the aluminum chloride solution as a standard, the quantity of aluminum oxide in the cement (the standard sample for chemical analysis, containing Al2O3 5.10%) is determined as 5.28%, and that aluminum content in potassium alum (for the commercially available reagent, the calculated ratio of Al is 5.66%) is 5.42%.
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  • Hiroshi TANAKA, Yoshihisa MIYAKE
    1973 Volume 22 Issue 3 Pages 335-336
    Published: March 05, 1973
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    For the detection of primary, secondary and tertiary aliphatic amines, nine amine hydrobromides were examined by silicagel thin-layer chromatography. Silicagel was used as an adsorbent containing a fluorescence indicator(Wakogel B-5F). Two solvent systems were used as the developers; butanol-acetic acid-water (4 : 1: 5) and phenol-water(8 : 3). After development, primary aliphatic amines were detected by visualizing under ultraviolet rays(3660 Å). These amines appeared as yellowish green spots on dark background. Secondary and tertiary aliphatic amines were detected by spraying with a 0.05% solution of 2', 7'-dichloro-fluorescein in ethanol and then visualizing under ultraviolet rays. They appeared as yellow spots on a yellow green background.
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  • Naoichi OHTA, Kazui SASAKI
    1973 Volume 22 Issue 3 Pages 336-339
    Published: March 05, 1973
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    The relationship between the concentration of the sample solution and the accuracy of atomic absorption spectrochemical analysis with standard addition method was studied.
    The experiment was carried out on the determination of strontium in the presence of aluminum as an interfering element. Preliminary test showed that the absorbance of strontium was interfered by aluminum almost in proportion to the logarithm of the concentration, and the calibration curve for strontium deviated from Beer's law in the low-concentration region of strontium in the presence of small amounts of aluminum. In the atomic absorption spectrochemical analysis with standard addition method, the concentration of the element in question in the sample solution had been prepared so as to come within the linear range of the relative concentration vs. absorbance curve. However, the results of the present experiment showed that the higher the concentration of the interfering element in the sample solution, the higher the positive error.
    From these results, it was found that the sample solution should be diluted enough prior to the analysis for the purpose of improving an accuracy of atomic absorption spectrochemical analysis with standard addition method, and the degree of dilution of the sample solution is able to decide as follows; the sample solution is diluted until the difference between the absorbance of the sample solution and that of the solution added a suitable amount of the element to be determined (for example, 1 ppm of strontium in the present experiment) to the sample solution coincide with the absorbance of the solution containing the same amount of the element which is added to the sample solution within the range of experimental error.
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  • [in Japanese]
    1973 Volume 22 Issue 3 Pages 340-349
    Published: March 05, 1973
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
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  • [in Japanese]
    1973 Volume 22 Issue 3 Pages 350-358
    Published: March 05, 1973
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    Download PDF (1349K)
  • [in Japanese]
    1973 Volume 22 Issue 3 Pages 359-372
    Published: March 05, 1973
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    Download PDF (21188K)
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