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Volume 36, Issue 12
Displaying 1-17 of 17 articles from this issue
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Toshiyuki MITSUI, Yukio MINAMI, Yoshikazu FUJIMURA1987 Volume 36 Issue 12 Pages 821-824
Published: December 05, 1987
Released on J-STAGE: May 25, 2010
JOURNAL FREE ACCESSThe determination of Paraquat was studied by means of curie point pyrolysis GC using an induction heating pyrolyser. The procedure for the determination is as follows. About 30 mg of a nickel potassium iodide mixture (Ni/KI =2, w/w) and 30 μg of a sample solution are put in the pyrofoil. After heating on a hot plate for 5 min at 120°C to evaporate water, the pyrofoil is placed in the pyrolyser and pyrolyzed for 4 s at 445°C. The Paraquat reacts with potassium iodide and forms methyl iodide. The peak area of methyl iodide is used for the determination of Paraquat. The measurement range of Paraquat was from 2.0 to 35.0 μg and R. S. D. (measured 10 times) was 1.01% to 16.61 μg of Paraquat. The sensitivity of this method is about 70 times higher than the standard pyrolysis method.View full abstractDownload PDF (559K) -
Toru NOZAKI, Hiroshi YAMASHITA, Hiroyuki TAKAHASHI1987 Volume 36 Issue 12 Pages 825-829
Published: December 05, 1987
Released on J-STAGE: May 29, 2009
JOURNAL FREE ACCESSIon flotation of twelve types of different metal ions were investigated in the pH range 1 to 13 with N-dodecanoyl-N-methyl-3-aminopropionic acid (DMA). A 20 ml solution containing (4.014.37) × 10-4 M of metal and (1.071.60) × 10-3 M of DMA was adjusted to the desired pH and subjected to flotation in a cell (20 cm × 2.7 cm i. d.) for 1020 min with a nitrogen bubble. Recoveries of Mn (II) and Co(II) at pH 6.5 to 10.0, Ni(II) at pH 7.5 to 11.0, Cu(II) and Cd (II) at pH 5.0 to 10.0, Zn (II) at pH 7.0 to 8.0, Pb (II) at pH 6.0 to 9.0, Al (III) at pH 4.0 to 4.5, Fe (III) at pH 3.5 to 9.0, Ga (III) at pH 3.5 to 4.3, In (III) at pH 3.0 to 10.0, and Bi (III) at pH 2.5 to 10.0 were 98100%, respectively. The composition of the floated complexes were determined to have a metal/reagent ratio of 1 : 2 for the divalent metal ions by the mole ratio method ; and a ratio of 1 : 3 for the trivalent metal ions by analysis of nitrogen and iron (III) in the scum. The stability constants of the complexes were also determined. This flotation method was successfuly applied during pretreatment in the determination of bismuth in electrolytic copper and iron (III) in the guaranteed reagents of copper (II) nitrate and lead (II) nitrate by using 11 of the sample solution in a cell (50cm × 6.6cm i. d.), respectively.View full abstractDownload PDF (686K) -
Kenzo YAMAMOTO, Hidetaka TSUJI1987 Volume 36 Issue 12 Pages 830-835
Published: December 05, 1987
Released on J-STAGE: May 07, 2010
JOURNAL FREE ACCESSA variation of head-space GC was investigated to determine hydrogen sulfide in water. A stripping chamber with 10 ml of solution containing 30% H2SO4 and 20% Na2SO4 was connected to the carrier gas line between the gas flow regulator and the column of a gas chromatograph. The solution in the chamber was bubbled with the carrier gas (N2). Water samples (10100 μl) were injected through a rubber septum into the chamber with a microsyringe. Sulfide and hydrosulfide ions in the injected water were converted to free hydrogen sulfide and stripped completely with the carrier gas in several minutes. The free hydrogen sulfide was introduced into the column and detected with a flame photometric detector. This method allows the analysis of small samples of water without pretreatment and is useful for any type of water. By this method, 0.02 ppm of hydrogen sulfide in 100 μl of water can be determined.View full abstractDownload PDF (856K) -
Mitsuru EBIHARA, Akihiko NEMOTO, Hideo AKAIWA1987 Volume 36 Issue 12 Pages 836-841
Published: December 05, 1987
Released on J-STAGE: May 29, 2009
JOURNAL FREE ACCESSFive trace chalcophile elements, Zn, Se, Cd, In and Te in chondritic meteorites were determined by radiochemical neutron activation analysis. Powdered samples of 50100 mg, along with standard samples prepared from reagents, were sealed individually in quartz tubes and irradiated in the JRR-4 reactor of the JAERI at a flux of 5.5 × 1013 n cm-2 s-1 for 12 h. After cooling for 34d, meteorite samples were fused with sodium peroxide and sodium hydroxide in zirconium crucibles in which the appropriate amounts of carrier solutions of the above elements had been taken and dried. After the fusion cakes were dissolved in water, sodium sulfide was added. Mixtures of hydroxide and sulfide precipitates involving Zn, Cd, In, and a part of Te were separated by centrifugation. Precipitates were then dissolved in nitric acid. Being converted to the chloride form, the elements separated as precipitates were loaded onto anion exchange resin to be separated successively from each other. Selenium and remainders of tellurium were precipitated as metallic forms by saturating with sulfur dioxide gas. Selenium and tellurium were separated by passing through anion exchange columns. Each element recovered was radiochemically purified and precipitated in an appropriate form to determine the chemical yield gravimetrically. The detection limits of the present method were deduced to be 70 ppb for Zn, 0.61 ppb for Se, 17 ppb for Cd, 3.3 ppb for In and 68 ppb for Te under the current conditions. Analytical precision and accuracy were estimated based on data from the Allende meteorite which was analyzed several times repeatedly.View full abstractDownload PDF (1012K) -
Masashi GOTO, Atsuko ISHII, Daido ISHII1987 Volume 36 Issue 12 Pages 842-850
Published: December 05, 1987
Released on J-STAGE: January 15, 2010
JOURNAL FREE ACCESSA simple method for preparation of samples for XRF analysis was developed using cellulose powder as matrix. The relative XRF (Kα, Lα, Lβ) intensities of 63 elements from Mg to U were measured, and then those of the other 11 elements were estimated from the results. The Kα X-ray intensity of K and Sr were used as the unit standard intensities for the elements of atomic number less than 19 and for the elements of atomic number larger than 19, respectively. The environmental standard samples (Chlorella, Pepperbush) were analyzed using the relative intensity values. The analytical results by the proposed method well coincided with the certified values offered from Environmental Agency, National Institute for Environmental Studies, Ibaraki, Japan. Green tea, black tea and flower tea leaves were analyzed as examples of natural samples by the method. The minimum detectable amounts, which depend on elements, were about 110 μg for the elements from Mn to Ba and those from Er to U. The proposed method is applicable not only to plant samples, but also to liquid samples.View full abstractDownload PDF (2320K) -
Tadashi NARA, Koichi OGUMA, Rokuro KURODA1987 Volume 36 Issue 12 Pages 851-855
Published: December 05, 1987
Released on J-STAGE: May 29, 2009
JOURNAL FREE ACCESSTwo FIA/AAS systems have been developed for the determination of Na and K in silicates. A split flow system allows a sample slug to be split into two flow channels leading to respective AAS detectors for Na and K, where special attention is paid to achieve a reproducible split by adding a third channel for the hydrodynamic balance of the system. The nonsplit flow system developed consists of two independent flow channels to which the sample solution is introduced alternatively by switching an interconnected, double six-way loop injection valve. The sample solution is prepared by fusing the silicate with a Li2CO3-H3BO3 (1 : 1) flux and leaching the cake in 1 M hydrochloric acid (1 mg silicate ml-1). Both flow systems permit high throughput of 120 sample solutions per hour. The procedures have been applied to standard silicate rocks of the US Geological Survey and the Geological Survey of Japan. The precision (R. S. D.) is 1% for Na and 0.5% for K for both systems.View full abstractDownload PDF (834K) -
Yukiko OKADA, Shohgo SUZUKI, Shoji HIRAI1987 Volume 36 Issue 12 Pages 856-861
Published: December 05, 1987
Released on J-STAGE: May 25, 2010
JOURNAL FREE ACCESSSelenium in thirty five kinds of soybean originating from Japan, China, Formosa, Burma, Brazil, Argentina and U. S. A. was determined by instrumental neutron activation analysis (INAA). Each soybean sample of ca. 12g was irradiated at the Musashi Institute of Technology Research Reactor (MITRR). The γ-ray spectra of the irradiated samples were counted by three methods. The first counting method was a long irradiation and counting method which acquired an activity of the long-lived 75Se formed by 5 h of irradiation. The second counting method was a long irradiation and coincidence counting method which acquired selectively an activity of 75Se emitting a cascade γ-ray pair. The third counting method was a short irradiation and counting method which acquired an activity of the short-lived 77mSe formed by 10 s of irradiation. Results for all the samples could be obtained by the long irradiation and coincidence counting method. However, some of the samples could not be analyzed by the other two counting methods. The values obtained by the three methods were found to be in good agreement with each other, but three replicate samples of the same origin yielded somewhat different results, mainly due to differences in sample size and compactness. Concentration of selenium in analyzed soybean ranged from 5200 ppb. Concentrations of selenium in soybean originating from China, U. S. A. and Japan were 530ppb, 50200ppb and 870ppb, respectively.View full abstractDownload PDF (873K) -
Reiko YOSIDA, Yuji WATANABE, Kenichi SATO, Masayoshi KAZAMA1987 Volume 36 Issue 12 Pages 862-866
Published: December 05, 1987
Released on J-STAGE: January 15, 2010
JOURNAL FREE ACCESSThe standard test of plastics for food packaging is defined by the Food Sanitation Act in Japan and the testing method depends on the material. Copolymers are examined by evaluating the contents of major components (>50%). Therefore, in case of ethylenevinyl acetate copolymers (EVA), it is necessary to know the vinyl acetate (VAc) content in EVA. VAc content in EVA is determined by Curie point pyrolysis GC. The pyrolysis conditions were chosen to minimize the decomposition of the ethylene chain, and to detect acetic acid (the pyrolysis products of VAc) with good sensitivity. Optimum pyrolysis temperature and time were 500 °C and 2 s, respectively. The minimum detectable amount of the present method was 10 μg VAc as absolute quantity; 1% vinyl acetate content in EVA. The precision was within 5.1 % R. S. D. (n=10). The determination of VAc in ocmmercial EVA products for food packaging was successfully achieved by the present method and the VAc contents proved to be less than 10%. It was found that when samples containing less than 2% alkaline earth metals, the yields of acetic acid were not affected by these metals.View full abstractDownload PDF (712K) -
Harunobu NAKASHIMA, Shinjiro HORI, Shozo IWAGAMI, Hiroyuki NAKAZAWA, M ...1987 Volume 36 Issue 12 Pages 867-871
Published: December 05, 1987
Released on J-STAGE: January 15, 2010
JOURNAL FREE ACCESSA simple, selective and highly sensitive method has been developed for the determination of dialkyltin compounds in textiles. Dialkyltin compounds (di-methyl, diethyl, dipropyl and dibutyl) were separated by reversed phase HPLC on a polymethacrylate column using 10 mM phosphate buffer (pH =2.3)-methanol (30 : 70) mixture as the mobile phase. Detection was made by a fluorescence detector with an excitation wavelength of 420 nm and an emission wavelength of 500 nm after postcolumn derivatization with Morin reagent. Dioctyltin was separated from the other dialkyltin compounds on a polyvinyl alcohol-copolymer column using a 10 mM phosphate buffer (pH=2.0)- methanol (40 : 60) mixture as the mobile phase. The detection limits of dimethyl, diethyl, dipropyl, dibutyl and dioctyltin compounds were 4.5, 1.8, 2.6, 6.0 and 40 ng, respectively. Dialkyltin compounds were extracted from textiles with methanol containing 0.05% of hydrogen chloride. The extract was alkalized by sodium hydroxide and was washed with hexane. The methanolic phase was reacidified by hydrogen chloride and the dialkyltin compounds were extracted into hexane-ethyl acetate. After evaporating the organic solvent, the residue was dissolved in the mobile phase, and the solution applied to the HPLC. Dialkyltin compounds in textiles were successfully cleaned up by this preparation and determined by HPLC with good selectivity. Recoveries of dibutyltin dichloride added to various textiles at the amount of 50 μg were about 72% in average. A large amount of dibutyltin compounds was found in a diapercover (900 μg/g). And a small amount of tributyltin compounds could be detected in the same sample by ECD- GC and GC/MS, as an impurity in the dibutyltin compounds.View full abstractDownload PDF (914K) -
Masakazu DEGUCHI, Hiroshi ICHIOKA, Kiyotoshi MORISHIGE, Itsuo OKUMURA, ...1987 Volume 36 Issue 12 Pages 872-874
Published: December 05, 1987
Released on J-STAGE: May 29, 2009
JOURNAL FREE ACCESSIron(III) reacts quantitatively with 2-hydroxy-5-sulfoaniline-N-salicylidene (HSS) to form a yellow complex in the presence of zephiramine at pH 4.05.2. The complex in an aqueous solution has an absorption maximum at 406 nm and the absorbance is stable for at least 24 h. The analytical procedure is as follows : To a sample solution containing less than 40 μg of iron (III), were added 5 ml of buffer sloution (0.5 M CH3COOH-0.5 M CH3COONa), 3 ml of 0.5 w/v% zephiramine solution and 2 ml of 0.3 w/v% HSS solution in DMF. Then the mixture was diluted to 25 ml with water (the final pH : 4.7+0.1). After 30 min, the absorbance was measured at 406 nm against the reagent blank. The calibration curve was linear up to 40 μg of iron(III) in 25 ml of the final solution. The relative standard deviation (n = 5) on the absorbance for 30 μg of iron(III) was 0.48%. The apparent molar absorptivity at 406 nm was 2.42 × 104 1 mo-1 cm-1. The molar ratio of iron (III) to HSS in the complex was estimated to be 1 : 2 by the continuous variation method. Aluminum(III), gallium(III) and copper(II) interfered seriously. The proposed method was applicable to the determination of iron in high purity zinc with satisfactory results, where the iron had been separated from interfering elements by extracting with isopropylether before the determination.View full abstractDownload PDF (589K) -
Takako MANO, Kiyoko MURAHATA, Yumiko OMURA, Shinji CHUSHI, Keiichiro H ...1987 Volume 36 Issue 12 Pages 874-877
Published: December 05, 1987
Released on J-STAGE: May 29, 2009
JOURNAL FREE ACCESSDetermination of arsenic oxides after plasma ashing of organic materials encountered with a difficulty, i.e., significantly low recovery of the oxides. A modified plasma apparatus having an electrostatically shielded chamber has been employed to overcome this difficulty: The organic materials were essentially oxidized by atomic oxygen without violent bombardments of energetic electrons and ions moving in the glow discharge region. A known amount of sodium arsenate {1530 mg As(V)} impregnated in 200 mg cellulose powder was plasma ashed and the ash residue was subjected to an ion chromatography. Nearly quantitative recovery was obtained with the modified apparatus while the recovery was approximately 60% when the electrostatic shield was eliminated. Arsenite ion was practically insensitive to the ion chromatography. However, when the arsenite-containing cellulose powder {4050 mg As(III)} was plasma ashed without the electrostatic shield, a recovery of about 60% was obtained as the form of arsenate. On the otherhand, when the same arsenite-containing cellulose powder was processed with the electrostatic shield, the recovery of arsenate was only 7%. Further oxidation of the latter ash material with hydrogen peroxide gave the quantitative recovery as the arsenate. Samples containing very low concentration of arsenate yielded somewhat low recoveries even with the use of electrostatic shield, but the recoveries were significantly raised by the addition of sodium carbonate as a fixative.View full abstractDownload PDF (794K) -
Yukio NAGAOSA, Nobuyoshi SATO1987 Volume 36 Issue 12 Pages 877-879
Published: December 05, 1987
Released on J-STAGE: May 29, 2009
JOURNAL FREE ACCESSA simple and convenient method for the determination of copper (II) has been developed, based on the extraction of the 8-quinolinol complex into propylene carbonate followed by differential-pulse polarography. A polarographic cell has been designed, in which the solvent extraction and deoxygenation can be done simultaneously by passing nitrogen through the aqueous and organic phases. An aqueous sample solution is placed with 2.0cm3 of 0.1mol dm-3 sodium acetate solution (pH 8.0), 1.0cm3 of 0.1 mol dm-3 sodium EDTA solution and then water to make up the total volume of 5.0cm3. To this solution is added 5.0cm3 of propylene carbonate solution containing 0.1 mol dm-3 tetrabutylammonium perchlorate and 0.1 mol dm-3 8-quinolinol. Emulsion is formed by stirring with a stream of nitrogen for 3 min. After the extraction, the three electrodes are inserted into the organic phase. The differential-pulse polarogram is recorded under the following conditions: scan rate 5 mV/s; modulation amplitude : 25 mV; drop-time; 2s. The peakcurrent at-0.45 V vs. Ag/AgCl is directly proportional to the Cu (II) concentration up to 3.0 μg/cm3. The lower limit of determination has been found to be 0.1 μg/cm3 Cu(II) in the aqueous phase. The method can be applied to the determination of copper in Bovine Liver and River Sediment of NBS standard sample.View full abstractDownload PDF (519K) -
Kazuyoshi TANAKA, Masanori SEKIMIZU, Masashi SAITO1987 Volume 36 Issue 12 Pages 880-881
Published: December 05, 1987
Released on J-STAGE: May 29, 2009
JOURNAL FREE ACCESSA theoretical analysis of the dynamic time response of a gas-sensing electrode is presented. The factors governing response time characteristics of the electrode are diffusions through both gas permeable membrane and internal film solution. The long response time of amine is due to considerable decrease in diffusion rate caused by chemical equilibration between amine and its conjugated acid in the internal film solution. The decrement of the apparent diffusion rate of amine is expressed by the product of the diffusion coefficient and the flux efficiency as defined by van der Pol. Based on this response time characteristic and Nikolsky-Eisenman's equation, a theoretical equation for the time- or concentration-dependent selectivity can be derived. The concentration-dependent change in experimental selectivity coefficients to trimethylamine is treated by applying the proposed equation. The result shows that the present approach provides a numerical prediction for the influence of interfering species on selectivity.View full abstractDownload PDF (358K) -
Shoichiro TAGAMI, Sachiko MIYAJIMA1987 Volume 36 Issue 12 Pages T129-T131
Published: December 05, 1987
Released on J-STAGE: May 29, 2009
JOURNAL FREE ACCESSAmmonia formed by Kjeldahl digestion of drug samples (primidone, panthothenic acid calcium salt, sodium glutamate, acetoaminophen and glycine) has been determined by use of an ammonia electrode. This method can eliminate the distillation-titration procedure for estimating the ammonia content of Kjeldahl digestion solutions. Since differences in the osmotic pressure and the solubility of ammonia between the standard solution and the Kjeldahl digestion solution often cause serious errors in the results, salt concentrations of both solutions should be kept equal. A linear calibration plot was obtained in the drug concentration range of 1 × 10-51 × 10-2 mol dm-3. The electrode method of analysis is rapid and simple. The results obtained by this method agree closely with those obtained by the customary distillation-titration method.View full abstractDownload PDF (456K) -
Tohru KUWAKI, Kyoji TÔEI, Masanori AKIBA, Mitsuko OSHIMA, Shoji ...1987 Volume 36 Issue 12 Pages T132-T135
Published: December 05, 1987
Released on J-STAGE: May 29, 2009
JOURNAL FREE ACCESSIn FIA, a gas-diffusion technique is highly selective, because there are only a few species which are generated as gases at room temperature. In this paper, the authors determined the total carbonate-carbon content in water by FIA with gas-diffusion unit assembly with a tubular microporous polytetrafluoroethylene (PTFE) membrane, which was reported previously. In this method, the sample was injected into a carrier stream of sulfuric acid in which carbonate and hydrogencarbonate ions injected were converted to gaseous carbon dioxide. The reagent stream which contained Cresol Red and was adjusted to pH 9.0, and the carrier stream, were fed to the gas-diffusion unit. Carbon dioxide passed through the PTFE membrane: the color change of Cresol Red to the acidic form was measured at 410 nm in a flow-through cell. The detection limit was 5 × 10-6 M (S/N=3), the response was linear up to 1.2 × 10-3 M, the sampling rate was 15 h-1, and the relative standard deviation obtained by ten injections of tap water (4.7 × 10-4 M) was 0.8%. The results obtained by the proposed method were in good agreement with those obtained by indirect photometric ion chromatography.View full abstractDownload PDF (605K) -
Computer aided data processing for carbon, hydrogen and nitrogen determination in elemental analysisMitsutoshi TANIMOTO, Akio HIKITA, Yasuharu IJUIN, Katsuko NOGUCHI, Set ...1987 Volume 36 Issue 12 Pages T136-T139
Published: December 05, 1987
Released on J-STAGE: May 29, 2009
JOURNAL FREE ACCESSThis report describes a personal computer system for processing the data obtained by an elemental analyzer with a differential thermal conductivity. The computer receives the data via a digital multimeter with automatically adjusted sensitivity according to the output level and a GP-IB data bus. The compositions of carbon, hydrogen and nitrogen are calculated and printed in a prescribed form which can be returned to a client, with no labor to calculate the composition from the recorder reading and to rewrite the result on a reporting sheet.View full abstractDownload PDF (695K) -
Kazuo IMAEDA, Keiko OHSAWA, Takaho WATANABE1987 Volume 36 Issue 12 Pages T140-T143
Published: December 05, 1987
Released on J-STAGE: January 15, 2010
JOURNAL FREE ACCESSA rapid method for the determination of cholesterol and squalene in skin surface lipid was established by reversed phase HPLC. Sebum was collected from different area of human body by the elution device. Sample was evaporated to dryness at 30 °C. The residue was dissolved with 50 μl of hexane and 10 μl aliquots of the solution was subjected to the HPLC. Optimum chromatographic conditions are as follows: ULTRON N-C18 (150 × 4.6 mm i. d.) as stationary phase, acetonitorile/tetrahydrofuran/water (42/50/8, v/v) as eluent at flow rate of 0.6 ml/min, and column temperature is 40 °C. Peak was detected by monitoring an absorbance at 210 nm. The retention times for cholesterol and squalene were 5 and 7 min, respectively. Linear calibration curves for cholesterol and squalene were obtained in the range 0.124 μg, 5 ng to 2.5 μg, respectively. The within-day relative standard deviations for cholesterol and squalene were less than 2.2%. The method was superior to the GC method in analytical time and precision.View full abstractDownload PDF (639K)
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