All issues
Volume 24, Issue 12
Displaying 1-16 of 16 articles from this issue
- |<
- <
- 1
- >
- >|
-
Chuichi WATANABE, Noriyuki YANAGISAWA, Yukio KUBO1975 Volume 24 Issue 12 Pages 737-741
Published: December 10, 1975
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSA new technique was developed for the extraction of dissolved gases, such as light hydrocarbons and hydrogen, from transformer oil. A 150 ml transformer oil was placed in a vacuum cylinder (about 700 ml) which was maintained under 1 mmHg with a vacuum pump. After the extraction, the extracted gas was quickly concentrated about 30 times, 10 mmHg to 300 mmHg, by pressing the piston under the pressure of atomosphere. The analyzed solutes in the concentrated gas were hydrogen (H2), methane (CH4), carbon monoxide (CO), carbon dioxide (CO2), ethylene (C2H4), ethane (C2H6), and acetylene (C2H2). The molecular sieve 5A (4-meter) and Porapak Q + Porapak T (each 2-meter) column were used. The column temperature was 60°C and helium was used as a carrier gas : 25 ml per min. The efficiency of extraction was as follows : H2 : 100, CH4 : 97.5, CO ; 100, CO2 : 88.6, C2H4 : 90.4, C2H6 : 89.4, and C2H2 : 92.1 percent. In quantitative analysis, the correction factor was applied to each solute and the detecting limit was as follows : H2 : 25, CH4 : 2.4, CO : 3.7, CO2 : 0.8, C2H4 : 0.9, C2H6 : 1.6 ppm in one ml oil. The coefficient of variation was within 6.3 percent. The number of analysis per day was 8- 10, which means about three times faster than in the conventional method.View full abstractDownload PDF (599K) -
Yoshinori KIDANI, Kouji NAKAMURA, Kenji INAGAKI, Hisashi KOIKE1975 Volume 24 Issue 12 Pages 742-745
Published: December 10, 1975
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSBenzylpenicillin (Pen-G) was extracted into nitrobenzene as an ion pair of tris(1, 10-phenanthroline)cadmium chelate. The chemical formula of the extracted species was confirmed to be [Cd(phen)3]-(Pen-G)2 by the continuous variation method. By measuring the amount of cadmium in nitrobenzene phase with an atomic absorption spectrophotometer, the quantitative determination of Pen-G was made indirectly.
In this experiment, a Hitachi 207 atomic absorption spectrophotometer was used, and the analytical line at 2288 Å of cadmium was used for the measurement using air-acetylene flame.
The procedure for the determination is as follows : 1 ml of an aqueous solution of 5.0×10-2 M tris (1, 10-phenanthroline)-cadmium chelate is taken into a 100 ml separatory funnel, 2 ml of phosphate buffer, 1 ml of 20% ammonium sulfate solution, and 1 ml of Pen-G solution of the concentration range of 5.0×10-4 M to 3.0×10-3 M are added and the resultant solution is diluted with deionized water to 10 ml. The mixed solution is shaken well with 10 ml of nitrobenzene for 5 minutes. The organic phase is centrifuged and absorbance was measured by an atomic absorption spectrophotometer.
Optimum pH range was 5.06.0 and the molarity of tris(1, 10-phenanthroline)-cadmium chelate was 16 times as much as that of Pen-G.
In order to prevent emulsification, 1 ml of 20% ammonium sulfate was added. Under these conditions, absorbance of cadmium in nitrobenzene phase shows a linear relationship over the range of 18.6 to 111.6 μg/ml of Pen-G. Any interference in the coexisting compounds, such as starch, lactose, dextrin, and saccharin-Na was not observed. The relative standard deviation was 2.14 and this method can be applied to the indirect determination of penicillin drug preparations.View full abstractDownload PDF (430K) -
Masako MAEDA, Akio TSUJI1975 Volume 24 Issue 12 Pages 745-750
Published: December 10, 1975
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSA fluorophotometric method for the determination of total amino acid in serum with the pyridoxal-Zn(II) reagent has been investigated and applied to the assay of enzyme activity based on the formation of amino acid in the assay mixture. Serum was deproteinized by heating it with diluted acetic acid or directly deproteinized with the pyridoxal-Zn(II) reagent. (A) 0.1 ml of serum was mixed with 0.1 ml of 0.05 N acetic acid, diluted to 1.0 ml with water, and heated for 5 minutes in a boiling bath. After cooling, the mixture was centrifuged and the concentration of amino acid in the supernatant was assayed by the pyridoxal-Zn(II) method. (B) 0.5 ml of the diluted serum (1 : 500) was mixed with 4 ml of the pyridoxal-Zn(II) reagent (0.01% pyridoxal HCI, 0.1% zinc acetate and 2 v/v% pyridine in methanol) and incubated at 37°C for 30 minutes. After centrifuging at 2000 rpm for 5 minutes, the fluorescence intensity of the supernatant was measured at excitation 390 nm and emission 470 nm. Carboxypeptidase B activity or acylase I activity was measured by determining fluorophoto-metrically L-arginie or L-leucine formed in the assay mixture after incubation. Benzoyl glycyl-L-arginine acetate or N-chloroacetyl L-leucine was used as substrate for each enzyme. These methods were more sensitive and simpler than the usual colorimetric method based on the ninhydrin reaction. Recoveries of alanine or glycine added to serum were (87.5100.0)% and their coefficients of variation were (0.224.80)%. Forty human sera were examined by the proposed method and the colorimetric ninhydrin method ; a good correlation was obtained between the two, with the relation y=0.962x+0.0058 and a relative coefficient of 0.949.View full abstractDownload PDF (759K) -
Study on residue analysis of pesticide. IShigeo ONO, Jiro HASEGAWA, Riichiro YANASE, Katumi SUGIOKA, Norihiro T ...1975 Volume 24 Issue 12 Pages 750-754
Published: December 10, 1975
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSResidue analysis for thiophanate-methyl[Dimethyl 4, 4'-ο-phenylene bis(3-thioallophanate)] (TM) and its degradation product, 2-methyl benzimidazolyl carbamate (MBC), of various plants was studied. TM and MBC were extracted together from plants with methyl alcohol. The solution was acidified with hydrochloric acid and TM was extracted with methylene chloride; TM and MBC were satisfactorily separated from each other. TM was cyclized to MBC by refluxing with copper acetate in 50% aqueous acetic acid. After clean up, MBC was determined by ultra violet absorption spectrophotometry. The corrected absorbance method was adopted in order to avoid the interfering absorbance due to plant components. The detection limits of TM and MBC were 0.02 ppm and 0.01 ppm, respectively, when 100-g samples were used.View full abstractDownload PDF (655K) -
Masahiro TSUBOUCHI, Tadao SAKAI1975 Volume 24 Issue 12 Pages 754-758
Published: December 10, 1975
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSOnium dyes such as pinacyanole, methylene blue, toluidine blue, crystal violet, and methyl violet are not quantitatively extracted with tetrapheyylborate anions into organic solvents from aqueous solutions in (210) minutes shaking. There is a difference in this respect between dye cations and metal chelate cations. The interference of tetraphenylborate in the extraction system with pinacyanole has been studied.
Pinacyanole cation is well extracted as an ion-pair with tetraphenylborate anion into nitrobenzene or chloroform in a few minutes of shaking (shaker: about 300 strokes/min) when [Pinacyanole]≥[Tetraphenylborate] in an aqueous phase. On the other hand, when [Pinacyanole]<[Tetraphenylborate], the pinacyanole cation is scarcely extracted in a few minutes of shaking even in the presence of perchlorate, and full color development on the extraction takes a long time of shaking as the concentration of tetraphenylborate increases. It is suggested that a 1 : 3 association complex is formed in the aqueous phase between pinacyanole cation and tetraphenylborate anion.View full abstractDownload PDF (645K) -
Hiroko WADA, Genkichi NAKAGAWA1975 Volume 24 Issue 12 Pages 758-761
Published: December 10, 1975
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESS4-(2-Thiazolylazo)-2-methylresorcinol (TAR-2 Me), 4-(2-thiazolylazo)-5-methylresorcinol(TAO) and 4-(2-thiazolylazo)-resorcinol(TAR-6Et) were synthesized. The acid dissociation constants of these reagents were determined spectrophotometrically in 20%(v/v) dioxane at μ=0.1 and at 25°C: the values of pkNH were 0.59, 0.93 and 0.73, pkoH(p) 6.54, 6.12 and 6.13 and pkoH(o) 11.8, 12.8 and 11.1 for TAR-2Me, TAO and TAR-6Et, respectively. TAR-2Me and TAR-6Et react with a number of metal ions to form the red or purple complexes as TAR does, while TAO does appreciably with a few metals. The formation constants of copper chelates in 20%(v/v) dioxane at μ=0.1 and at 25°C were log KcuA=16.0, 15.8, 15.8, and log KHCuHA=4.25, 4.75, 3.72 for TAR-2Me, TAO and TAR-6Et, respectively. TAO forms less stable metal chelates, because the methyl group atο-position of azo group in TAO may hinder the rotation of resorcinol on the formation of metal chelates.
TAR-2Me and TAR-6Et are much similar to TAR rather than TAC[2-(2-thiazolylazo)-4-methylphenol] in the behaviors of chelate formation, and very good metal indicator for Cu-EDTA titration. TAO can be used for colorimetry of copper, or mercury without serious interference with other metal ions.View full abstractDownload PDF (411K) -
Application of controlled potential coulometry to the automatic recording of liquid chromatography. VIIYoshinori TAKATA, Yoshijiro ARIKAWA1975 Volume 24 Issue 12 Pages 762-767
Published: December 10, 1975
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSRapid separation of rare earths by cation-exchange chromatography was studied with the use of a coulometric detector. Sulfonated polystyrene resins of 8, 10, and 12% cross-linkage were used with lactate solution as eluents. The elution of rare earths was very much affected by the pH of the eluent. The results indicate that the pH-gradient elution is effective for rapid separation. Good separation was achieved by the pH-gradient elution of initial pH 3.4 and final pH 5.0. The elution of rare earths was accelerated with the addition of sodium chloride to the eluent. Some heavy metals which interfere under ordinary conditions were mostly eliminated by controlling the sodium chloride concentration.of the eluent. Concentrations higher than 0.1 M of sodium chloride decrease the column efficiency. The raise of temperature improves the column efficiency and the increase of cross-linkage improves the separation factor between Y and Dy. Taking into account of these results, it was possible to separate 16 rare earths (Sc and Y included) in less than 80 min. with the use of strong cation-exchange resin of particle size (811) μm and of a steep pH-gradient lactate solution method.View full abstractDownload PDF (685K) -
Sumio YAMASAKI, Hiroki OHURA, Issei NAKAMORI1975 Volume 24 Issue 12 Pages 767-771
Published: December 10, 1975
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSThe differential titration of sulfite and thiosulfate ions with mercuric chloride (HgCl2) solution has been studied by short-circuited amperometry using a rotating platinum wire electrode (1000 rpm) as the indicator and SCE as the reference electrode.
Sulfite and thiosulfate ions, respectively, from Hg-(SO3)22- and Hg(S2O3)22- quantitatively at pH 78. But, in the presence of large excess of formaldehyde to sulfite ion, Hg(SO3)22- is not formed. On the basis of these phenomena, sulfite or thiosulfate ion in their mixture is determined differentially. To prevent air oxidation of sulfite ion, glycerin is added to ca. 5 (v/v) % in the sodium sulfite solution. The recommended procedure is as follows: To a sample solution, ca. 10 ml of 1 M KNO3 and ca. 10 ml of 0.2% gelatin are added. The solution is adjusted to pH 78 with the diluted perchloric acid or sodium hydroxide. The solution is diluted to 100 ml with deaerated water. The sample solution is titrated amperometrically with (0.050.0005) M HgCl2 standard solution by Pt rotating electrode (1000 rpm) at ca. 20°C. The concentration of sum of sulfite and thiosulfate ions is found by this titration.
The second sample solution, to which 2 ml of 1 M formaldehyde is added, is titrated with HgCl2 standard solution, then the concentration of thiosulfate ion is found. The sulfite ion can be determined from the difference of the two concentrations. The whole titration procedure requires about 10 minutes. Each ion of sulfite and thiosulfate can be determined at the concentration range of ca. 5×10-5 M10-2M and the relative errors are ca. ±3%, even in the case of lower concentration (5×10-5 M). Sulfate, carbonate, chloride, azide, nitrite and chlorate ions in the concentration ranges up to 100 times of the mixture of sulfite and thiosulfate ions do not interfere the determination. It is an advantage of this method that the titration is applicable to the solution containing oxidation reduction substances such as nitrite and chlorate ions.View full abstractDownload PDF (642K) -
Selective gas-chromatographic detector by use of ionselective membrane electrode. VITsugio KOJIMA, Yoshimitsu SEO, Junichi SATO1975 Volume 24 Issue 12 Pages 772-776
Published: December 10, 1975
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSA method for selective detection of mercaptans by use of a silver/sulfide ion-electrode has been developed. Components eluted from a G.C. column are introduced into an absorption tube in which a suitable silver nitrate solution {(1×10-51×10-3)M} flows at a constant flow rate. The solution emerging from the absorption tube is passed into a micro-cell equipped with a silver/sulfide ion-electrode. When mercaptans are dissolved in the absorption solution, the silver ion concentration is lowered by formation of insoluble mercaptide, and changes in the silver ion concentration are detected by the corresponding changes in the ionelectrode potential. The potentiometric output of the ion-electrode is converted by an antilogarithmic converter, and recorded. A chromatogram showing only peaks due to mercaptans is obtained. When it is desired to detect all sulfur compounds, a postcolumn reactor is used where each component undergoes hydrogenolysis, and hydrogen sulfide formed from sulfur compounds is introduced into the absorption solution. Thus a chromatogram recorded peaks of all sulfur compounds is obtained by use of the hydrogenolysis reactor. In this method, sulfur compounds can be easily distinguished from other compounds and mercaptans can be readily identified from other sulfur compounds by comparing both chromatograms.View full abstractDownload PDF (604K) -
Yukio ONO, Shigeyuki TANAKA1975 Volume 24 Issue 12 Pages 776-782
Published: December 10, 1975
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSMass spectrometric identification of oxygenated compounds in geranium oil was investigated with a Hitachi RMU-6E spectrometer coupled with a K-53 gas chromatograph {5% PEG-20 M, 2m×3mm I.D., (70220)°C, 4°C/min} and a Hitachi RMU-7L, double-focusing mass spectrometer. Gas chromatography was carried out on a Shimadzu GC5A PF equipped with an FID {5% PEG-20 M, 2m, 4m×3mm I.D., (80240)°C, 6°C/min}. Geranium oil of Seto bourbon, Japan (Perargonium roseum bourbon) and several imported geranium oils were examined for the comparison of gas chromatograms and detection of adulterants. In GC-MS measurements, peaks of main oxygenated compounds in the oils were overlapped by those of sesquiterpene hydrocarbons. Silica gel chromatography using n-pentane and ethylether effectively separated these hydrocarbons. The identification of oxygenated compounds in the ether fraction revealed that the differences in the gas chromatograms were mainly attributed to the quantities of formates and acetates of citronellol and geraniol, α-terpineol and sesquiterpene alcohol. Moreover, the ether fraction was applicable to the detection and isolation of adulterants in imported geranium oils. Besides already known components of geranium oil, there were several isolated compounds in one of the imported oils examined: 3, 5, 5-trimethyl-1-hexyl acetate, diphenyl methane and phenylether. These compounds have not been found in natural geranium oil.View full abstractDownload PDF (935K) -
Kamihiko ITSUKI, Joji ABUKAWA, Yoshinobu TOFUKU1975 Volume 24 Issue 12 Pages 782-787
Published: December 10, 1975
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSThe method for the determination of trace mercury in selenium by means of heating followed by collecting in a gold trap was investigated. To avoid vaporization of selenium, which causes error due to adsorption of generated mercury vapor in deposited selenium or selenium oxide, sample was covered with tin powder and was made to alloy in the heating process at 400°C under argon atmosphere. Outline of the analytical method is as follows. Sample of 0.1g selenium is taken in a portion of a quartz glass boat and is covered with 2.5g of tin powder. The boat is put into a quartz glass tube in which air has been replaced with argon gas. Sample is heated at 400°C in argon atmosphere. Generated mercury vapor is led to a gold trap and collected. Amalgamated mercury is then released by heating at 700°C and absorbancy at the wavelength of 253.7 nm is measured. Depending upon the mercury content, i.e., 3 ppm and 11 ppm Hg in selenium, 0.1g and 0.03g of samples were used respectively in this method. The results were in good agreement with those obtained by the atomic absorption method preceded by dithizone extraction- stannous chloride reduction process using sample of 0.4g or 0.1 g. The method of dithizone extraction was also improved in this experiment with following conditions: use of ammonium nitrate as salting-out reagent, double dithizone extractions followed by back extraction with hydrochloric acid and repeating the whole extraction procedure again, and addition of buffer solution of pH 5.3 for the purpose of saving time of pH adjustment to avoid loss of mercury.View full abstractDownload PDF (1000K) -
Tsutomu TSUKADA, Yukio HIYAMA, Noriyuki WATANABE, Eiji NIKI1975 Volume 24 Issue 12 Pages 787-791
Published: December 10, 1975
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSThe marginal oscillator-detector by means of the frequency modulation for nuclear quadrupole resonance spectrometer causes an incidental output (offset) due to its frequency characteristics. There are two disadvantages resulting from this offset. One is the limitation in performing the high gain amplification of the detected signal, and the other is the shift in the baseline. In order to overcome these difficulties, we constructed the NQR spectrometer with an automatic amplitude control on one side of the excursion of the bi-directional square wave for frequency modulation. This automatic control system enables the high gain amplification and accomplishes the flat baseline over a wide frequency range. Moreover, it is proved that the spectrometer is highly sensitive not only to chlorine and nitrogen compounds (35Cl, 37Cl and14N) but also to copper(I) compounds (63Cu and 65Cu) which show a wide line-width requiring a large modulation amplitude.View full abstractDownload PDF (669K) -
Tomoo MIWA, Takayoshi TOYOTA, Atsushi MIZUIKE1975 Volume 24 Issue 12 Pages 792-794
Published: December 10, 1975
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSTo establish the method for preparing glassy carbon electrodes which give reproducible anodic stripping curves and small background currents, the effects of various factors (the kind of glassy carbon, surface roughness, chemical pretreatments, etc.) on the shape of the stripping curves of copper and mercury have been studied. The recommended method is as follows. The surface of a glassy carbon rod (Tokai Electrode Mfg. Co. Grade GC-20, 5mmφ×50mm) is polished with an emery paper (No.5/0) followed by a chromium(III) oxide suspension (ca.0.5μmφ) and covered with epoxy resin adhesive at (6080)°C. Then the rod is sheathed with Teflon. After complete setting, the surface of the electrode is polished with a series of emery papers of increasing fineness (Nos. 0 to 5/0), then with the chromium(III) oxide suspension. The electrode is washed with 7 M aqueous ammonia, ethanolic 5% sodium hydroxide solution, and water, successively, with the aid of ultrasonics. The electrode is held in a supporting electrolyte at+0.8 Vvs. SCE for a definite time, and then rinsed with water.View full abstractDownload PDF (544K) -
Yukimasa HASE, Emiko FUKAZAWA, Masayoshi YAMAO1975 Volume 24 Issue 12 Pages 794-797
Published: December 10, 1975
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSUrea-melamine resins are widely used as wood adhesives. The infrared spectral method for the determination of melamine contents in urea-melamine resins was studied. The KBr-tablet method was satisfactory for this purpose, and potassium thiocyanate was most suitable for the internal standard. It was found that the ratio of the optical density at the wavenumber 810cm-1, X (melamine), to the optical density at 2050 cm-1, Y (KSCN), of the spectrum was proportional to the ratio of melamine to KSCN. A calibration curve was constructed for the relation between X/Y and melamine/KSCN by the standard mixtures. The reproducibility and recovery test of this method was examined on the standard samples prepared by different processes. The standard deviation of this method was below 0.5% as melamine content. This method is suitable for routine analysis because of its accuracy, simplicity, and rapidity.View full abstractDownload PDF (665K) -
Hiroshi OGURO1975 Volume 24 Issue 12 Pages 797-799
Published: December 10, 1975
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSAntimony in fire retardant polypropyrene could be extracted into boiling HCl (6N) layer from xylene layer containing dispersed sample and antimony content was determined by atomic absorption spectrophotometry. The outline of the extraction method was as follows: 250 mg of sample was taken into a Kjeldahl flask connected with a reflux condenser. 20 ml of xylene was added and heated gently. 30 ml of HCl was then added and the mixture was heated with boiling state for 30 minutes. The HCl layer was filtered through a filter paper to a volumetric flask after cooling. By repeating the extraction with HCl twice, more than 99% of antimony was extracted. The conditions for atomic absorption were : wavelength 2175.8 Å, lamp current 17 mA, burner height 10 mm, air flow-rate 7.0 1/min, acetylene flow-rate 1.5 1/min and entrance slit width 0.1 mm. A linear calibration curve was obtained within the concentration range of 0 to 75 ppm for antimony. No appreciable interference was caused by other elements likely to be present in sample. The coefficient of variation for a sample containing 7.70% Sb2O3 by the present method was 2.30%.View full abstractDownload PDF (527K) -
Satori UTSUMI, Tadao OKUTANI, Tatsuo YAMADA1975 Volume 24 Issue 12 Pages 799-801
Published: December 10, 1975
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSIodine does not react with sodium azide however, the following reaction is catalytically promoted in the presence of micro amounts of sulfut compounds.
2 NaN3+I2→2 NaI+3 N2
This catalytic reaction is applied to the photometric determination of trace amounts of thiocyanate ion. One milliliter of an aqueous solution (1×10-3 N in KIO3 and 1×10-2 N in KI) and 0.5ml of the 1 N acetic acid are placed in a glass tube with a glass stopper. After standing this solution for 5min at 25°C, 3ml of the sodium azide solution (20g/100ml) and 5ml of the sample solution containing this cyanate ions are added. Three minutes after the mixing 0.5ml of the 1N potassium iodide solution is added. Then, the absorbance of the solution is measured at 350nm. By this method, the concentration range from 0.005ppm to 0.08ppm of thiocyanate ion in 5ml of the sample solution can be determined accurately. Fe (III), Cu (II), CN- and SO32- interfere with the determination of thiocyanate ion.View full abstractDownload PDF (347K)
- |<
- <
- 1
- >
- >|