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Volume 39, Issue 3
Displaying 1-13 of 13 articles from this issue
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Kaneharu KATO, Kyoichiro TAKASHIMA1990 Volume 39 Issue 3 Pages 139-143
Published: March 05, 1990
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSThe determination of B in mixed solutions of heavy water (D2O) and light water (H2O) by ICP-AES using Cu as an internal standard element (ISE) was investigated. Real heavy water samples of 16 ml were pipetted respectively into volumetric flasks of 20 ml and diluted to the mark with light water after the addition of 200 μg Cu. In calibration, Cu internal standard calibration solutions prepared with light water were used. The obtained linear dynamic range, background equivalent concentration (BEC), and detection limit (3σ, n=10) were 0.01 to 100 μg B/ml, 0.17 μg B/ml and 1.50 ng B/ml, respectively. The B concentrations of 0.01, 0.1, 1, 5 and 10μg/ml in mixed solutions of heavy water (80 vol % ) and light water (20 vol % ) were determined with the relative standard deviations (n=10) of 20, 7.5, 3.5, 3.0 and 1.0%, respectively. It was found, furthermore, that the present method could be applied to the determination of other elements. That is, Si and Al could also be determined by the use of Cu as the ISE, and Mg, Cd and Mn could be determined by the use of Cr as the ISE.View full abstractDownload PDF (763K) -
Yuuko ISHII, Kazuyoshi TAKIYAMA1990 Volume 39 Issue 3 Pages 145-149
Published: March 05, 1990
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSSpinach, begonia, garden sorrel, goosefoot and other plants contain calcium oxalate crystals in their leaves. Calcium oxalate is developed to protect the protoplasm from the toxic action of oxalic acid, which is produced by metabolism. In the present investigation, it was found that the calcium oxalate crystals in plants were monohydrate or dihydrate, each having its typical shape. Calcium oxalate crystals in begonia were dihydrate and those in garden sorrel and goosefoot were monohydrate. Most calcium oxalate crystals in spinach were dihydrate with about 20% monohydrate. Calcium oxalate was also prepared by the precipitation of calcium and oxalate at various concentrations and pH's. Calcium oxalate monohydrate or dihydrate was produced by changing the reagent concentration and pH of the reacting solution and also by the presence of citrate, malate or succinate. Calcium oxalate monohydrate crystallized as long hexagonal plates and its dihydrate crystallized as octahedrons. The conditions for the formation of monohydrate and dihydrate calcium oxalate crystals in plants was partially elucidated and the calcium oxalate crystals of plants could be distinguished as monohydrate or dihydrate from their morphological characteristics.View full abstractDownload PDF (1182K) -
Hidekazu YAMADA, Tomoo HATTORI, Takeshi MIYAMURA, Manami OKADA, Akiko ...1990 Volume 39 Issue 3 Pages 151-157
Published: March 05, 1990
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSSoil extracts containing appreciable amounts of dissolved organic compounds often present difficulties in their analysis for selenium. As a method for eliminating the difficulties, the addition of a small amount of copper ion to the soil extracts was found to be effective for suppressing interference caused by the organic compounds in the extracts. By applying this result, a method for the fractional determination of selenium in soil extracts was developed. Selenium(IV) was determined by HPLC with fluorescence detection after reaction with 2, 3-diaminonaphthalene. Selenium(VI) was first reduced to the quadrivalent state with potassium bromide and hydrochloric acid as reducing reagents and copper ion, then the total inorganic selenium was determined by the same method as the determination of selenium(IV). The amount of selenium(VI) was calculated by subtracting the amount of selenium(IV) from the total inorganic selenium. Total selenium in the soil extract was also determined by the same method as the total inorganic selenium after oxidizing the organic compounds in the extract. The amount of organically-bound selenium was estimated from the difference between the total selenium and the total inorganic selenium. The proposed method could be applied to the fractional determination of selenium in the soil extract with satisfactory reproducibility and recovery.View full abstractDownload PDF (850K) -
Susumu YAMATO, Hiroyuki WAKABAYASHI, Masaharu NAKAJIMA, Kenji SHIMADA1990 Volume 39 Issue 3 Pages 159-162
Published: March 05, 1990
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSDeactivation of endogenous thiol compounds in biological samples was studied by using maleic anhydride. An excess amount of maleic anhydride in ether was added to the solutions containing glutathione or coenzyme A. The reaction of maleic anhydride with the thiol compounds and the hydrolytic degradation of maleic anhydride were followed by the measurement of remaining thiols with Ellman's reaction. About a 5 molar excess amount of maleic anhydride was enough to eliminate thiol compounds in the assay mixture. Thiol compounds had been reacted with maleic anhydride within 5 min and then the reducing ability diminished. Excessive maleic anhydride was also hydrolyzed rapidly and then lost its reactivity to thiol compounds. It was recognized that maleic anhydride was a useful reagent for elimination of endogenous thiol compounds in biological samples, especially for a series of determinations of thiols newly produced by the subsequent enzymatic reaction.View full abstractDownload PDF (513K) -
Yasuyo TAKAHATA, Yoshikuni YAKABE, Masato KATO, Mitsuo AKIBA, Yoshihis ...1990 Volume 39 Issue 3 Pages 163-166
Published: March 05, 1990
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSOpen tubular columns having inner diameters from 0.5 mm to 1.2 mm were prepared and examined regarding the dependency of column efficiency on the inner diameter of the open tubular column in the range of carrier gas flow rate usually used on the packed column. At carrier gas flow rates above 10 ml/min, HETP decreased and consequently column efficiency increased with increasing column diameter. A column 40 m in length with a 1.2 mm inner diameter and 1 μm film thickness showed a theoretical plate number of 20300 for the naphthalene peak. The maximum sample injection volume for this column was about 4 μg. The relative standard deviation for ten repeated quantitative analysis of 40 ppm naphthalene was 0.472%. In conclusion, the wide diameter open tubular column can be operated easily at higher flow rates of carrier gas (2060 ml/min) compared to the capillary column. It can be used without a split system and a large volume of sample can be directly injected, making possible a highly sensitive and reliable analysis.View full abstractDownload PDF (601K) -
Takako MANO, Satomi NAKAMORI, Keiichiro HOZUMI1990 Volume 39 Issue 3 Pages 167-170
Published: March 05, 1990
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSLow-temperature ashing of organic samples with oxygen plasma has been currently carried out within the glow discharge region of a plasma chamber operated by an external electrode system. However, ion chromatographic analysis of the residual ash showed that samples containing NaCl or NaBr yielded significant low recoveries of halogenide as well as oxyhalogenide as a byproduct. This was interpreted to be due to energetic electrons and ions on the sample material. Therefore, a new plasma chamber design consisting of a glass bell jar and a modified internal electrode system was tested for milder oxidation. In this version, sample boats could be situated within a cylindrical sample container that was placed on the lower electrode and electrostatically shielded by wire mesh to eliminate electrons and ions. The results showed higher recoveries of halogenides were obtained with the electrostatic shielding than without it. However, some oxyhalogenides were still found as byproducts. Finally, carbon dioxide plasma was used in place of oxygen plasma to oxidize the organic samples. Quantitative recoveries of chloride or bromide could be obtained, eliminating any detectable signals of oxyhalogenides in the ion chromatogram. X-Ray photoelectron spectroscopy also proved the absence of oxyhalogenides. It was apparent that the use of carbon dioxide plasma for the low-temperature ashing was superior to that of oxygen plasma in terms of quantitative recovery of slightly volatile inorganic components. Such gentle oxidation might be due to the sole presence of atomic oxygen in carbon dioxide plasma whereas in oxygen plasma, ordinary molecular oxygen might also participate in the oxidation process.View full abstractDownload PDF (636K) -
Hirohito NAKA, Hirofumi KURAYASU, Yasuo INOKUMA1990 Volume 39 Issue 3 Pages 171-175
Published: March 05, 1990
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSDetermination of trace amounts of acid soluble aluminium in iron and steel by graphite furnace AAS was studied. In order to avoid interferences encountered in practical analysis, the following analytical conditions were employed. (1) sulfuric acid was used for the sample decomposition. (2) pyrolitically coated graphite tubes were used as furnaces. (3) as a matrix modifier magnesium sulfate was added to sample solutions. (4) ramp mode heating (13002000°C, 30 s) was performed at the ashing step. The proposed method was applied to the determination of aluminium in iron solution. The relative standard deviations obtained with the present conditions were less than 7% (concentrations of aluminium were in the range of 00.05 mg/l) and the detection limits (3σ) were 0.75 μg/l. Interferences from manganese and silicon were almost negligible when concentration of manganese was 50 mg/l and that of silicon was 25 mg/l. This method was applied to the determination of acid soluble aluminium in carbon steel with satisfactory results.View full abstractDownload PDF (632K) -
Hitoshi MUKAI, Yoshinari AMBE1990 Volume 39 Issue 3 Pages 177-182
Published: March 05, 1990
Released on J-STAGE: January 18, 2010
JOURNAL FREE ACCESSICP-MS was applied to the measurement of stable isotope ratios of lead, which are used as an indicator of the source of lead in airborne particulate matter. For the measurement of lead isotopes ratios, the influences of machine conditions, lead concentration and matrix elements to the precision and accuracy of the measurements were studied. At a scanning mode, dwell time of 40160 μs gave the best precision to the isotope ratio measurements; about 0.3% of R. S. D. for 206Pb/207Pb and 206Pb/208Pb, 0.6 % for 206Pb/204 Pb. Precision of the measurement was better at a high concentration of lead in sample solution. The observed value of 206Pb/207Pb ratio was not affected by the lead concentration, but in the cases of 206Pb/204Pb and 206Pb/208Pb, about 1% of the value changed in the observed ratios with the lead concentration of 100500 μg/l. Six matrix elements (Na, K, Ca, Mg, Al, Fe) did not affect the observed isotope ratios up to 200 mg/l. The lead isotope ratios of reference materials {Urban Particulates (NIST) and Vehicle Exhausted Particulates (NIES)} were measured by using two kinds of sample; crude sample and lead-isolated sample from matrix elements by anodic deposition. Both cases gave the same isotope ratio values, therefore, lead isotope ratios in airborne particulate samples can be measured by ICP-MS without any separation of lead from matrix elements.View full abstractDownload PDF (865K) -
Reiko YOSHIDA, Yuji WATANABE, Masayoshi KAZAMA1990 Volume 39 Issue 3 Pages 183-187
Published: March 05, 1990
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSThe standard test of plastics for food packaging is defined by the Food Sanitation Law in Japan and the testing methods vary depending on the material. Copolymers are examined by evaluating the contents of major components (>50%). Therefore, in case of styrene (St) copolymers, it is necessary to know St content in the copolymers. St concentration in copolymers was determined by Curie point pyrolysis GC. Open tubular glass columns (1.2 mm i.d.) were chosen to separate the pyrolysis products of the St copolymers with high resolution. Best resolution was obtained on serially coupled columuns coated with dimethyl silicone (G-100) and polyethylene glycol (G-300). The precision was within 2.8% R.S.D. (n=10). The determination of composition in commercial St copolymer products (styrene-acrylonitrile resin, acrylonitrile-butadiene-styrene resin etc.) for food packaging was successfully achieved by the present method and the St concentration proved to be more than 50%. This method is suitable to know the composition of the copolymers simply by taking pyrograms of the samples since it dose not require any pretreatment to remove additives.View full abstractDownload PDF (604K) -
Hiroshi MIKASA, Yoshikazu HORI1990 Volume 39 Issue 3 Pages 189-191
Published: March 05, 1990
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSUranium was extracted with tributylphosphine oxide (TBPO) into toluene from 4 M hydrochloric acid solution, and determined by fluorometry following carbonate fluoride fusion. The extractability was 96% by the second extraction from the aqueous phase after the first extraction. 1% TBPO/toluene and 30 min shaking time was used for each extraction. The presence of 7.5 μg Fe(III) interfered with the determination, while other coexisting elements did not. Interference by Fe(III) was suppressed by adding hydroxylamine in aqueous phase. Aluminium nitride was dissolved by heating in a sealed Teflon vessel with 8 M hydrochloric acid. Trace uranium as low as 1.9 ng per sample was determined.View full abstractDownload PDF (297K) -
Miyoko IZAWA, Takashi KORENAG, Teruo TAKAHASHI1990 Volume 39 Issue 3 Pages 193-195
Published: March 05, 1990
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSThis study discussed a method for the determination of inorganic arsenic in arsenic compounds and dimethylarsonic acid (DMA) mixture by AAS after benzene extraction. The ion associate of arsenic(III) was extracted with benzene from hydrochloric acid solution (1012 M) but neither arsenic(V) nor DMA were extracted. Titanium chloride(III) dissolved in concentrated hydrochloric acid was used to reduce arsenic(V) to arsenic(III). The reduction of 10 μg of arsenic(V) was carried out by using 2 ml of 10% titanium chloride (III) solution at 60°C for 30 min. As a result, the arsenic (V) was completely reduced to arsenic(III) but the reduction of DMA was negligible. This method was applied to the determination of arsenic ion in oxidation degradation reaction products of wastewater containing DMA. The detection limit was 1 μg/l and the relative standard deviation was 1.8% at 30 μg/l.View full abstractDownload PDF (403K) -
Takeshi NAGANUMA, Satoshi TUZUKI, Jiye JIN1990 Volume 39 Issue 3 Pages 197-199
Published: March 05, 1990
Released on J-STAGE: June 19, 2009
JOURNAL FREE ACCESSA method for the fluorornetric determination of uranium, based on a solvent extraction of an ion associate formed between Rhodamine B cation and 2-thenoyltrifluoroacetone(TTA)-metal chelate anion with benzene, is described. The procedure for the construction of the calibration curve is as follows. Varying amounts of uranium standard solution and 2 ml of 2 M ammonium acetate buffer solution are mixed. The solution is adjusted at pH 6.0 and 10 ml of 0.3% Rhodamine B are added. It is then shaken for 5 min with 10 ml of 0.01 M TTA benzene solution. The fluoresence of the organic phase is measured at 545 nm (excitation) and 570 nm (emission) for uranyl-TTA-Rhodamine B complex. The fluorescence intensity is linearly related to the concentration of uranyl ion in the range of 0.05 ppm to 1 ppm.View full abstractDownload PDF (362K) -
Masao UMEMOTO, Koji HAYASHI1990 Volume 39 Issue 3 Pages T35-T38
Published: March 05, 1990
Released on J-STAGE: January 19, 2010
JOURNAL FREE ACCESSDependence of SBR (signal-to-background ratio) on rf power as a function of carrier gas flow rate in ICP-AES was investigated on the spectral lines of Cr I 425.435 nm and Ca I 442.673 nm as a soft analytical line, and Zn I 213.856 nm, La II 408.671 nm, Ti II 336.121 nm, Fe II 259.940 nm and Zn II 202.548 nm as a hard analytical line, respectively. In the case of the soft analytical lines, the SBRs decreased continuously with an increase in the rf power regardless of the carrier gas flow rate. On the other hand, in the case of hard analytical lines, the maximum point of the SBR appeared with an increase in the rf power when a higher carrier gas flow rate was applied. In particular, the SBR increased with an increase in the rf power on Zn II 202.548 nm at 0.60 l/min of carrier gas flow rate. Thus, the rf power and the carrier gas flow rate should be carefully selected for the hard analytical lines in order to obtain the best SBR values.View full abstractDownload PDF (568K)
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