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Volume 28, Issue 3
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Tatsuro TARUI, Hiroshi TOKAIRIN1979 Volume 28 Issue 3 Pages 133-137
Published: March 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSA graphite furnace atomic absorption spectrometry using a tantalum boat was studied for the determination of uranium. A Perkin-Elmer 460 atomic absorption spectrometer, a HGA 2100 flameless atomizer, and a uranium hollow cathode lamp made by Westinghouse were involved for this purpose. With a regular graphite tube, uranium was not atomized at 2800°C, whereas with a pyrolytic coating tube uranium became atomized at the same temperature but memory effect was noticed. This is probably due to the carbide formation and to the diffusion of uranium atom vapor through walls of the graphite tube. To avoid this effect and to ensure high atomizing temperature, a tantalum boat (3 mm thick) was inserted into a graphite tube, and 20μl of uranium solution was injected onto the boat. The optimum conditions involved : wavelength 358.5 nm, drying at about 150°C for 20 s, charring at about 500°C for 10 s, atomizing at about 2500°C for 10 s, and Ar flow rate of 30 ml/min. Interference of mineral acids was serious : 0.1 M HCl, 0.1 M HNO3, 0.01 M H2SO4 and 0.01 M H3PO4 decreased the uranium absorption. Calibration curve was linear over the range of (03)μgU/ml. The limit of detection was as low as 2 ng for S/N=2.View full abstractDownload PDF (702K) -
Kiyoshi NISHI, Yasuko ASHIDA, Nobutsura TAN, Norio SUGITA1979 Volume 28 Issue 3 Pages 137-142
Published: March 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSNereistoxin monoxide (4-dimethylamino-1, 2-dithiolane 1-oxide) and nereistoxin (4-dimethylamino-1, 2-dithiolane) which were considered to be metabolites of cartap hydrochloride {2-dimethylaminotrimethylene S, S'-bis (thiocarbamate) hydrochloride} in soil and plant tissue, were determined by gas chromatography (GC) and polarography. On GC analysis, nereistoxin monoxide and nereistoxin dissolved in acetic acid-methanol were directly injected since nereistoxin monoxide is stable in acidic solution. The minimum detection amount of nereistoxin monoxide and nereistoxin with a FPD was as low as 1 ng. Nereistoxin monoxide in acidic solution showed a fourelectron reduction wave due to the formation of thiosulfinate accompanied with an adsorption wave on polarography. Nereistoxin monoxide was easily hydrolyzed in alkaline solution to give 2-dimethylamino-3-mercaptopropanesulfinic acid (DMSA) and the reduction wave disappeared. DMSA showed an anodic wave due to the formation of mercaptide accompanied with an adsorption wave and the wave height is proportional to the concentration. Nereistoxin monoxide and nereistoxin were determined separately by the anodic wave (E1/2=-0.30 V vs. SCE) from DMSA and the reduction wave (E1/2=-0.52 V vs. SCE) after the hydrolysis of the mixture since nereistoxin was stable in alkaline solution. The hydrolysis of nereistoxin monoxide in aqueous solution was base-catalyzed pseudo-first reaction within pH 812. The half-life (t1/2) of this compound at pH 10.5 was 10 min at 25°C.View full abstractDownload PDF (1035K) -
Microdetermination of aluminum and copper as aluminum-quinalizarin lake and copper-thiooxine complexPhotoacoustic spectrometry of solid samples. IISeiji KAWAMOTO, Yu YOKOYAMA, Shigero IKEDA1979 Volume 28 Issue 3 Pages 142-147
Published: March 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSPhotoacoustic spectroscopy was applied to determination of microamount of Al and Cu as Al-quinalizarin ake and Cu-thiooxine complex, respectively. Al-quinalizarin lake was formed by dropping 5 mm3 of Al standard solution on quinalizarin test paper and by exposing the paper to ammonia and subsequently to acetic acid vapor. Cu-thiooxine complex was formed by dropping 5 mm3 of the mixture of Cu standard solution and 20% ascorbic acid on 8, 8'-diquinolyldisulfide test paper and by exposing the paper to ammonia. The photoacoustic spectra and diffuse reflectance spectra almost agreed with each other for quinalizarin as well as Al-quinalizarin lake. Although an absorption maximum appeared at 430 nm in the photoacoustic spectra of Cu-thiooxine complex, as in the absorption spectra of this complex in CHCl3 solution, its diffuse reflectance spectra did not reveal the maximum clearly. Thus photoacoustic technique gave spectra closer to those obtained by the conventional photometry. Determination of Al and Cu was performed by measuring the intensity of photoacoustic signals at 620 nm and 430 nm, respectively. By plotting the normalized intensity of the signals against the amount of the metal ion, linear calibration curves were obtained over the concentration range of 0.03 to 0.6 μg for Al and of 0.1 to 1.0μg for Cu.View full abstractDownload PDF (1006K) -
Kiyoshi MASHIMO, Masanori MATSUKAWA, Tohru WAINAI1979 Volume 28 Issue 3 Pages 147-153
Published: March 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSIt was difficult to measure the pmr spectra of aromatic carboxylic acids because of their low solubilities in carbon tetrachloride, benzene, or chloroform. In this paper, their pmr spectra were satisfactorily measured by using the shift reagents, Eu(FOD)3 and Pr(FOD)3, in carbon tetrachloride-methanol. Adding Eu(FOD)3 or Pr(FOD)3 to the carbon tetrachloride-methanol solution of aromatic carboxylic acid, Eu(FOD)3 and Pr(FOD)3 caused the induced shift of each proton of the acid at high and low field, respectively. The direction of shift was opposite to the ordinary induced shift. In this case, the shift reagent reacted with the associated molecule between carboxylic acid and methanol to form the complex, in which the vector joining the metal atom to each proton and the principal magnetic axis of the molecular complex differed from the angle in the shift reagent and aromatic carboxylic acid system. The magnitude and the direction of the induced shift were affected by the substituent groups and their positions. Therefore, the sign and size of these shifts proved some informations on the structural analysis of aromatic carboxylic acids. The quantitative determination of hydroxy benzoic acid isomers were carried out by utilizing this phenomenon, and good results were obtained.View full abstractDownload PDF (1024K) -
Hiroto WATANABE, Nobuo YAMAGUCHI1979 Volume 28 Issue 3 Pages 154-158
Published: March 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSZinc reacts with 2-(8-quinolylazo)-4, 5-diphenylimidazole (QAI) to form a water-insoluble chelate, which can be rendered soluble in water with a nonionic surfactant. The blue zinc chelate in a micellar solution of Triton X-100 has an absorption maximum at 582 nm. The color develops rapdily and is stable for at least 24 h. The absorbance of the chelate at 582 nm is constant over the pH range 5.0 to 10.5, whereas that of QAI is constant from pH 4.0 to 9.0. A combined use of sodium citrate, N-(dithiocarboxy)-sarcosine (DTCS) and sodium metaphosphate (MP) is effective in order to mask foreign ions. The procedure is as follows. Place the solution containing less than 20 μ of zinc in a 25 ml volumetric flask. Add 1 ml of 1 M citrate, 1 ml of 20%(w/w) MP solution, 2 ml of pH 9.0 ammonia buffer, 30 mg of DTCS and finally 2 ml of QAI solution (QAI, 0.050 g : Triton X-100, 20 g : water, 80 g). Dilute to the mark with water. Measure the absorbance in an 1-cm cell against a blank at 582 nm. Beer's law holds for {(120)μg Zn/25 ml} and the molar absorptivity is 8.3 × 104. The following amounts (μg) of foreign ions are tolerated for the determination of 5.0 μg of zinc : Fe(III) 600, Mn(II) 30, Co(II) 60, Ni(II) 1, Cu(II) 20, Cd 20. The method can be applied to the determination of zinc in several tens to several hundreds ppb level in water.View full abstractDownload PDF (953K) -
Azuma KIDO, Nobuyasu SHIGEMORI1979 Volume 28 Issue 3 Pages 158-163
Published: March 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSA method was described for the rapid determination of trace elements (Ba, Be, Bi, Cd, Cr, Cu, Ga, Mg, Mn, Pb, Ti, V, Zn) in dust falls by photoelectric emission spectrometry. Dust falls collected by using deposit gauge were filtered, dried, and ground for analysis. A small amount of the prepared dust sample was diluted with graphite powder, and mixed with aluminum dioxide buffer (final concentration : 10%). The mixture (25 mg) was placed into a cup electrode (i.d. 4 mm, depth 4 mm) and excited by DC arc (10 A, analytical gap 4 mm). A spectral line intensity was measured by a partial integration method. The coefficient of variation and detection limit of 13 elements ranged (416)% and (440) ppm, respectively. In this method, the aluminum dioxide-graphite buffer effectively controlled the matrix effect and increased the precision of determination. SN ratios increased by the partial integration of spectral line intensity for volatile elements. In this way both volatile and nonvolatile elements could be determined simultaneously.View full abstractDownload PDF (966K) -
Yuzo TAMARI, Keizo HIRAKI, Yasuharu NISHIKAWA1979 Volume 28 Issue 3 Pages 164-169
Published: March 05, 1979
Released on J-STAGE: May 07, 2010
JOURNAL FREE ACCESSA 2, 3-diaminonaphthalene (DAN)-cyclohexane extraction method is described for the determination of selenium in sediments. A sediment sample weighing 0.05 to 0.2 g is opened up with a mixture of hydrofluoric acid, nitric acid and perchloric acid, and evaporated to strong fumes of perchloric acid. DAN, EDTA and sodium fluoride are added to the perchloric acid solution and selenium is extracted from the mixed solution (pH 1) with cyclohexane. Selenium in the organic layer is stripped by nitric acid, and subsequently determined fluorometrically with DAN after reduction to selenium (IV) in a boiling hydrochloric acid solution. This method is excellent for the determination of selenium in view of conveniency, rapidity, high sensitivity (detection limit : 0.5 ng Se) and good reproducibility. Results are also quoted on the analysis of biological materials such as NBS Orchard Leaves and Bovine Liver for selenium.View full abstractDownload PDF (981K) -
Masamitsu KATAOKA, Masahiko TAKAHASHI, Tomihito KAMBARA1979 Volume 28 Issue 3 Pages 169-173
Published: March 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSThe oxidation of iodide ion by peroxoborate ion takes place in acidic milieu and is catalyzed by a trace amount of tungsten(VI) or vanadium(V). When the concentrations of peroxoborate and sulfuric acid were kept in a large excess in comparison with that of iodide ion, the reaction rate was proportional to the product of catalyst and iodide ion concentrations. The reaction rate was followed by measuring the concentration of iodide ion by means of an iodide ion-selective electrode. The appropriate reaction conditions were decided graphically. The most suitable concentrations of sodium peroxoborate, potassium iodide and sulfuric acid for the determination of tungsten(VI) were found to be 12.5 mM, 60 μM and 75 mM, respectively, and for the determination of vanadium(V), they were 12.5 mM, 50 μM and 30 mM. A calibration curve of good linearity was obtained over concentration range 0 to 6.0 μM of tungstate. The calibration curve for orthovanadate showed also a good linearlity in the concentration range below 40 μM, but deviated at the higher concentration. However, the determination up to 100μM was feasible. Interferences of diverse ions were tested, among which Fe(III) and Mo(VI) interfered strongly.View full abstractDownload PDF (634K) -
Kazuo IMAEDA, Keiko OHSAWA, Yoshihiro YOSHIMURA1979 Volume 28 Issue 3 Pages 173-178
Published: March 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSStructural variation in deterioration process of plastics and rubber has been investigated by infrared spectrometry (IR), by gel permeation chromatography as well as by tensile strength tests. But, to determine the index, the oxygen determination technique has not been effectively studied yet in spite of its expected benefits about the quantity of used sample and the preciseness of the method. The experimental results of the direct oxygen determination applied to the investigation was compared with those of IR, tensile strength tests and elongation tests. As samples, were used polypropylene (PP), an antioxidant containing PP, degradation accelerator containing PP, and valcanized natural rubber rings. Rubber used were unconditioned, underwent 4-fold extention, and contacted with copper under 4-fold extention prior to the tests, respectively. These PP and rubbers in each condition were irradiated with ultra violet rays (UV). The rubber samples without undergoing UV irradiation were also employed. All samples thus prepared were subjected to the investigations of time-course change during (910) days by direct oxygen determinations, as well as by IR, by tensile strength tests, and by elongation tests. In accordance with deterioration process of PP and rubbers, there was found to be a correlation between the oxygen content and the tensile strength. The pure PP samples and those containing antioxidants, degradation accelerators gave remarkable defference about the variation of their oxygen content in the induction period. The deterioration rate of the rubbers was most increased by UV irradiation, next by contacting with copper and then by loading mechanically. Thus the oxygen determination was an effective method to obtain the indices of deterioration as well as to characterize the samples mechanochemically. As the deterioration can be determined only with 1 mg of the sample within 15 minutes, and ±0.3% in the range of error, the information about the deterioration can be obtained by this method faster than IR, or elongation technique.View full abstractDownload PDF (892K) -
Kazuo SETA, Mitsunori WASHITAKE, Toshio ANMO, Nobuharu TAKAI, Tsuneo O ...1979 Volume 28 Issue 3 Pages 179-183
Published: March 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSThe determination of the nucleic acid components is one of the most important steps in sequence analysis of nucleic acids and also in minute analysis of free nucleic acid components in cells or tissues. Further progress in this field largely depends on the development of high-resolution and rapid techniques for qualitative and quantitative analysis of a number of nucleic acid components. Various liquid chromatographic methods had been developed for these purposes. Yet, ion-exchange chromatography, introduced by Cohn, had retained its leading position in this field due to its versatility and reliability. The microreticular or the pellicular ion-exchange resins had been used for the separation of nucleic acid components. However, the separation were not satisfiable in the time and in the resolution. We have previously reported that the high-speed and high-resolution anion-exchange chromatography of body fluids, such as urine, blood plasma or serum, and hemodialyzed fluid, can be achieved by the macroreticular anion-exchange resin system. The system used a 50 × 0.4 cm I.D., column packed with Diaion CDR-10 anion-exchange resin and the linear ammonium acetate gradient to elute the UV-absorbing constituents of body fluids. In this paper, we report on the utilization of the macroreticular anion-exchange resin system for the rapid and high-resolution separation of the nucleic acid components of human erythrocytes. In the analysis of TCA extracts from erythrocytes, at least 50 components as UV-absorbing constituents were detected. The assignments of the chromatographic peaks were carried out by comparing to those of standard nucleic acid components and they were found to be nucleic acid components. Then, we comfirmed that the macroreticular anion-exchange resin system is a compositive and minute separation system for those components and related compounds. Furthermore, quantitative analysis of adenine and guanine nucleotides of some animal whole blood were performed by this separation system.View full abstractDownload PDF (956K) -
Analytical application of organic reagents in hydrophobic gel media.VShunsuke IDE, Makoto TAKAGI, Keihei UENO1979 Volume 28 Issue 3 Pages 184-187
Published: March 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSUsing a column of polystyrene gel beads impregnated with chlorobenzene solution of dithizone, preconcentration of heavy metal ions from dilute aqueous solution was investigated. Cu(II), Cd(II), Zn(II) and Pb(II) were trapped in the column as dithizonate complex when respective solution passed through the column under suitable pH conditions. The original green color of the column turned to brown, orange, red purple and deep red from the top, respectively. Cu(II), Cd(II) and Zn(II) could be back-extracted by simply eluting with 6N hydrochloric acid at a flow rate of (1.01.4) ml/min. Pb(II) was not recovered quantitatively with 6N hydrochloric acid but quantitatively with 1 N hydrobromic acid. Concentration factor for these metal ions ranged from 5 to 30. Nickel(II) reacted only very slowly with dithizone, so that it was separated from other metals. A comparison of column performance with respect to the types of solid support, such as polystyrene-divinylbenzene (2%) copolymer, Shimalite F(support for gas chromatography, Shimadzu Seisakusho Ltd.) and Amberlite XAD-4 (Rohm & Haas Co.), was also made using dithizone, and the first one was found to be most suitable for the present purpose.View full abstractDownload PDF (768K) -
Yushi SHICHI, Shigeru FUKUSHIMA, Hisako KATO, Hidenari INOUE, Tsuneo S ...1979 Volume 28 Issue 3 Pages 187-189
Published: March 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSIn the chemical analysis for nitrogen oxides, nitrogencontaining compounds in sample gases are oxidized and absorbed in the absorption solution as NO2- and NO3- to give positive errors to the analytical results when the sample gases are oxidized by ozone. Recently it has been pointed out that ammonia gas remaining in the flue gases after the removal of nitrogen oxides leads to a positive error in the analytical results. In the present work we have studied the effects of ammonia and hydrogen cyanide on the chemical analysis and proposed an improved method to prevent their interferences. Nitrate ions resulting from the reaction of ammonia with ozone were about (58)% of the ammonia concentration and brought about positive errors in the analysis of nitrogen oxides. These interferences could be effectively removed by using 0.0036 N sulfuric acid as absorption solution and shaking it for one minute to absorb ammonia gases prior to the reaction with ozone. About 0.2% of hydrogen cyanide gas were converted to nitrogen oxide, causing slightly positive errors. However, this interference could be eliminated by using an absorption solution of zinc sulfate and shaking that solution for one minute to increase the absorbtion-speed of hydrogen cyanide gas. In addition, it was found that less than 1000 ppm of pyridine gas do not interfere with the analytical results for nitrogen oxides.View full abstractDownload PDF (500K) -
Hikaru SATSUMABAYASHI, Yuuhei NAKAZAWA1979 Volume 28 Issue 3 Pages 189-192
Published: March 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSMethods of determination of chloropicrin in air, river water and soil by gas chromatography were studied. Air was taken in a tedlar bag, and chloropicrin in the air was determined with an electron capture detector, or by the use of the cold trap method with liquid oxgen and a flame ionization detector. In the samples containing 1000 ppm, 1 ppm and 10 ppb of chloropicrin, about 90% and (8090)% of the chloropicrin remained in a glass bottle and a tedlar bag after 24 and 48 hours, respectively, but below 4 ppb recoveries was not enough though the samples were determined immediately after preparation. Chloropicrin in river water was extracted with hexane, and determined with an electron capture detector. About 100% of 4 ppm, 500 ppb, 10 ppb and 1 ppb of chloropicrin in the water were recovered by this method. We applied Tagawa's method to analysis of chloropicrin in soil, and recoveries were satisfactory. Minimum detectable concentrations of chloropicrin in river water and soil were 0.1 ppb and 5 ppb, respectively. The present methods were applied to determine chloropicrin in air, river water and soil of a place disinfected with it.View full abstractDownload PDF (544K) -
Satoshi KAWAI, Akiko Uji, Takeo OHNO1979 Volume 28 Issue 3 Pages 193-195
Published: March 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSApricot Kernel Water contains mandelonitrile and free benzaldehyde. A method for gas chromatographic(GC) determination of them is described. Procedure 1 : for determination of the total of both components, 0.25 ml of Apricot Kernel Water is diluted with water to 5 ml and 2 drops of 10% ammonia solution is added. The total of free benzaldehyde and one produced from mandelonitrile is extracted with 2 ml of ethyl acetate containing 2.0 mg of naphthalene as an internal standard saturating with sodium chloride. An aliquot of the extract is subjected to GC. GC conditions are as follows : 5% DEGS, 1.5 m, 70°C, FID. Procedure 2 : for determination of mandelonitrile, the same volume of sample solution is treated. with 0.3 ml of 1% hydroxylamine hydrochloride solution, which react with free benzaldehyde. After an excess of hydroxylamine is removed by adding 0.2 ml of acetone, the mixture is treated with 2 drops of 10% ammonia solution and the benzaldehyde produced corresponding to mandelonitrile is determined as directed in Procedure 1. This method was applied to analysis of a colored preparation composed of Apricot Kernel Water, Inf. Seneg. Rad. and Brocin (1 : 4 : 5), in which all mandelonitrile was found to have been decomposed to benzaldehyde.View full abstractDownload PDF (471K) -
Hisatake NARASAKI, Katsuhiro OGAWA, Kikuo TSUJIMOTO1979 Volume 28 Issue 3 Pages 195-196
Published: March 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSLess than 10 μg or 10 ppm phosphorus in organic materials was determined by a low-temperature ashing-molybdenum blue spectrophotometry. After a sample had been treated by low-temperature asher, the residue was taken up and fumed with 15 cm3 of 30 (w/w)% perchloric acid. After cooling the perchlonic acid solution was transferred to a 300 cm3 separatory funnel, to which 10 cm3 of 5 (w/v)% ammonium molybdate was added and the mixture was diluted to 100 cm3 with water. Phosphorus was extracted into 10 cm3 of butyl acetate by shaking the mixture for 1 min. The organic phase was transferred to a 25 cm3 volumetric flask and was diluted with ethanol to the mark. After the addition of 0.2 cm3 of 5 (w/v)% tin(II) chloride, the absorbance was measured at a wavelength of 725 nm against water. Results on the determination of phosphorus in rice and filter papers were quoted and compared with those by other ashing methods. Recoveries were checked with tetraphenylphosphonium chloride, yielding 95.4% as an average.View full abstractDownload PDF (335K) -
Yoshifumi AKAMA, Toshiyuki ISHII, Toshio NAKAI, Fumikazu KAWAMURA1979 Volume 28 Issue 3 Pages 196-199
Published: March 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSThe use of the enrichment process by extraction technique prior to the determination by atomic absorption spectrophotometry is very effective to remove interferences and to concentrate the trace element. The procedure was applied to the determination of the trace amount of manganese by the extraction of its complex of 4-benzoyl-3-methyl-1-pheny1-5-pyrazolone(BMPP) into MIBK, and subsequently by the atomic absorption spectrophotometry. The standard analytical procedure is as follows: After neutralizing the sample solution containing less than 4.0 μg of manganese, it was adjusted to pH 8.0 by adding 5 ml of NH4OH-NH4l buffer solution, and then the solution was made up to 40 ml with distilled water. After the manganese was extracted as the Mn-BMPP complex into 10 ml of 0.1% (w/v) BMPP-MIBK solution by shaking them for 5 min, the separated organic phase was centrifuged for 5 min to remove the trace of water in it. Atomic absorption measurements were done for the organic phase thus obtained. This method was applied to determine manganese in carbonated drinks by means of a standard addition procedure.View full abstractDownload PDF (600K) -
Toshiaki NOMURA, Takeshi SAKAI1979 Volume 28 Issue 3 Pages 199-201
Published: March 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSAs some mercury(II) chelate compounds form mixed-ligand complexes with many anions, such as cyanide, thiocyanate, thiosulfate, iodide, and bromide, the spectrophotometric or volumetric determination of those ions has been proposed by using the mixed-ligand complexes. But, as the formation of the mercury(II) mixed-ligand complexes containing both of the chelate ligand and anions is not selective, the other metal chelate, which forms the mixed-ligand complex specifically, have been investigated. Copper(II) ethylenediaminetetraacetate (Cu-EDTA) reacts with cyanide in an alkaline solution in the pH range 9.512.0 to form the mixed-ligand complex of Cu-EDTA/cyanide in the 1:1 molar ratio, and the apparent stability constant (log K) is 4.7 at ionic strength 0.10 and pH 10.0. The mixed-ligand complex is stable when the molar ratio of cyanide to Cu-EDTA does not exceed 4. On the other hand, Cu-EDTA does not react with the ions, such as bromide, iodide, thiocyanate, and thiosulfate, which react with the mercury(II) ethylenediaminetetraacetate to form the mixed-ligand complexes. Therefore, the specific determination of cyanide may be possible using the reaction such one shown by Cu-EDTA, although the molar absorption coefficient of the copper(II) complex is too small to utilize practically for the direct spectrophotometric determination of cyanide.View full abstractDownload PDF (469K) -
Kazuo KUGA, Isao SUGAYA, Kanji TSUJII1979 Volume 28 Issue 3 Pages 201-205
Published: March 05, 1979
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSPolyimide resins (polyimide-isoindoloquinazolincdione) were decomposed by a dry ashing technique and analyzed for the four elements by flame (air-acetylene) atomic absorption spectrometry. A specially designed quartz ashing vessel was used to control the temperature and atmospheric composition for the ashing. Recoveries of four elements decreased with increasing ashing temperature, being dependent on crucible materials. The recoveries of copper and sodium were not satisfactory when the platinum and quartz crucible were used, respectively. These losses were attributed to the retention of respective metal on the crucible used, which was demonstrated by radioisotopic tracer method. The increase of oxygen content in atmospheric gases resulted in a slight increase of temperature and shortened the ashing time. In practice volatile organic solvent in the resin was first removed by increasing the heating temperature from 100 to 500°C and then the oxidant gases consisting of oxygen and air in equivalent volume was supplied to the ashing vessel at a flow rate of 1.2 l/min. The temperature was raised to 600°C to complete the ashing for one hour. The ash was dissolved in 1 ml of nitric acid and stored in 2 N nitric acid, followed by atomic absorption measurements. The standard deviation of (3.37.9) % came out.View full abstractDownload PDF (923K) -
Effect of substituent groups on fluorescence. IKinpei YAMAMOTO, Hisakazu SUNADA, Nobuyori YONEZAWA, Akinobu OTSUKA1979 Volume 28 Issue 3 Pages 205-208
Published: March 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSSeveral 2-hydroxyazomethines having various substituent groups were prepared and the effect of the substituent groups on the fluorescence intensity of aluminum chelates of these compounds was investigated by the use of Free-Wilson's method, which has been known as a methematical technique describing structure-biological activity relationships of a series of chemical analogs. The mathematical model used is based upon the assumption that the fluorescence intensity in a series of analog can be given as the sum of the "over-all average" values and the contribution of each substituent. For the testing compounds successful solutions of the equations based on the model were obtained. So it became obvious that this method could be applicable to the studies of fluorescence intensity-structure relationships as well as structure-biological activity relationships.View full abstractDownload PDF (753K) -
Masakichi NISHIMURA, Akiko NIINO, Shinichiro NORIKI1979 Volume 28 Issue 3 Pages 208-211
Published: March 05, 1979
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSFerrous-1, 10-phnenthroline chelate, Fe(II) (phen)32+, is quantitatively extracted into 1, 2-dichloroethane by ion-association with methyl orange, and this extraction is applied to a sensitive spectrophotometric determination of iron(II). The procedure is as follows: To a sample solution containing up to 2×10-7 moles of iron are added 5 ml of 3 M hydrochloric acid and 1 ml of 10% hydroxylamine solution. After 10 min, 1 ml of 1 × 10-3 M 1, 10-phenanthroline solution is added and the pH is adjusted to 6.0 with 6 M ammonia. After 30 min, the solution is diluted to about 50 ml with water in a separatory funnel. And then, 10 ml of 3 × 10-3 M methyl orange (MO) solution and 10 ml of 1, 2-dichloroethane are added, and the funnel is shaken for 5 min. The organic phase is dried with filtration through a paper filter and the absorbance at 422 nm is measured against the reagent-blank as a reference. Beer's low is held up to 2 ×10-7 moles of iron in a 10 ml extract., The extracted chelate has a composition of Fe(II) (phen)3(MO)2, and its molar absorptivity at 422 nm is 4.5 × 104. The absorption maximum is due to the absorption of methyl orange extracted into the organic phase. The absorption maximum of methyl orange in an aqueous solution of pH 6.0 is in 470 nm, but all the extracted associates of Zn(phen)3(MO)2, (zephiramine)(MO) and (tetraphenylarsonium) (MO) show the absorption maxima at around 421 nm.View full abstractDownload PDF (508K)
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