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Volume 35, Issue 7
Displaying 1-12 of 12 articles from this issue
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Yoshio UMEZAWA1986 Volume 35 Issue 7 Pages 559-573
Published: July 05, 1986
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSRecent studies from the author's laboratory were critically reviewed. Four different types of new sensors were constructed and evaluated : i) Uphill transport membrane electrodes, ii) Electrochemical immunoassay with protein-pendant liposomes and ion selective electrodes, iii) Biological polyanion sensor using lipophilic macrocyclic polyamines and iv) Carrier transport membrane electrode. Also, fundamental studies on the recognition of chemical species at membrane surfaces were made. As for the liquid membrane, some comparative measurements were made between membrane potentials and extractability of solvent extraction for several common ion associate systems. A new empirical rule was found from this. In this connection, mass transport across the interface of liquid membrane ion selective electrodes was measured simultaneously with membrane potentials using a specially designed microcell. Photo-responsive crown ethers were used to construct photo-switching ion selective liquid membrane sensors. Also, the charge separation process at the CuS solid membrane and LaF3 solid membranes was studied in terms of surface stoichiometry vs. membrane potentials. pH response of platinum electrodes in various protein solution was correlated with the isoelectric point of each adsorbed protein.View full abstractDownload PDF (2204K) -
Yasuhiko NISHIKAWA, Fujio MORISHITA, Tsugio KOJIMA1986 Volume 35 Issue 7 Pages 575-578
Published: July 05, 1986
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA FIA of urate using a uricase-immobilized open-tubular reactor is described. The decrease in the absorbance at 290 nm resulted from the conversion of urate into allantoin is measured by a dual-channel FIA system with a single UV detector, which is composed of a unease-immobilized reactor and an empty tube in parallel. A sample solution injected is split and sent into these two tubes. The residence times in these tubes are different and after confluence a pair of peaks appear in a FIA-gram at every injection. The urate concentration can be evaluated from these peaks. The design of the optimal geometry of the FIA system is especially important to avoid overlap of the peaks and was carried out based on the Tailor-Aris equation. Excellently reproducible results were obtained despite a somewhat complex flow system used and a linear calibration curve was obtained in the urate-concentration range of 0.01 to 0.5 mM. The presence of L-ascorbic acid in the sample hardly interfere with the urate determination.View full abstractDownload PDF (665K) -
Han-guo HUANG, Xiao-xia GENG1986 Volume 35 Issue 7 Pages 579-584
Published: July 05, 1986
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThis paper reports the optimum conditions and effect of coexisting ions for the fluorometric determination of samarium and europium with 2-thenoyltrifluoroacetone(TTA) and 1, 10-phenanthroline (phen) micellar solution of nonionic surfactants, Tween 20, 40, 60, 80 and Triton X-100, and TTA-phen-Tween 20 micellar systems were adopted for the simultaneous determination of samarium and europium in rare earth minerals and mixed rare earth chloride. The proposed method is superior to the solvent extraction method not only in simplicity, rapidity, stability and sensitivity but also in decreasing the fluorescence quenching effect without interference of Ca2+ up to 0.1 M (20000 times for Eu3+). Optimum pH region was 5.35.5 being lower than benzene extraction system, while optimum concentrations of reagents, excitation and emission wavelengths are all the same except for the slight difference in the detection limit. The detection limits in the Tween 20 system were 0.3 ppb for europium and 7.0 ppb for samarium, while those of the Tween 60 system were 0.2 ppb and 4.0 ppb for Eu and Sm, respectively, by the use of Tianjin Optical WFD-9 type (made in China) spectrofluorometer. The recoveries of samarium and europium were found to be about 94% with 2.9% of relative standard deviation in the Sm/Eu ratio of 220 using TTA-phen-Tween 20 system. The recommended procedure for the determination of samarium and europium in rare earth sample was as follows: To 13 ml of the sample solution containing 5 μg rare earth oxide/ml was added 5 ml of 0.1 M sodium acetate-acetic acid buffer solution and 2.5 ml of 5 × 10-3 M TTA-5 × 10-3 M phen-1%(v/v) Tween 20 solution. Adjust pH to 5.5 and dilute to 25 ml with water. Then the fluorescence intensity of the solution was measured with excitation wavelength at 345 nm, with emission wavelength at 614 nm for europium and at 649 nm for samarium. The results analyzed for a mineral and mixed rare earth chloride samples agreed well with those obtained by other method.View full abstractDownload PDF (885K) -
Kazunobu TAKAHASHI, Yoshihiko OHYAGI1986 Volume 35 Issue 7 Pages 585-589
Published: July 05, 1986
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA simple and rapid procedure for the determination of tin in environmental samples such as bottom sediments by AAS has been studied. In order to avoid loss of tin compounds by volatilization, decomposition of the sample with a mixture of hydrochloric and nitric acids (3 : 1) was performed in a Kjeldahl flask equipped with a condenser. After decomposition, the solution was filtered and diluted with 1M hydrochloric acid. The atomic absorption of tin was measured in an air-hydrogen fuel-rich flame at 224.6 nm, and the content of tin in the sample was determined by standard addition. This procedure was applied to the determination of tin in bottom sediments of a marine environment at Tanabe Bay, Wakayama Pref. As a result, the contents of tin found in the bottom sediment at Tanabe Bay was estimated to be 8.829.3 μg/g (dry).View full abstractDownload PDF (771K) -
Akikazu MATSUMOTO, Yoshimitsu HIRAO, Masatoshi IWASAKI, Etsuko FUKUDA, ...1986 Volume 35 Issue 7 Pages 590-597
Published: July 05, 1986
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSLead concentration in rock, shell and algae was determined by graphite furnace atomic absorption spectrometry (GFAAS), prior to this lead was separated using an anion exchange column of HBr media. To prevent lead contamination during handling and dissolution, the analysis was performed in a clean laboratory and clean bench, and acids used in the procedure were purified by redistillation with quartz and Teflon wares. The sample was completely decomposed with HF (not used for shell and muscle), HNO3 and HClO4, and dried. The sample was dissolved in 0.5 M HBr, spiked with 212Pb and was passed through a column of Bio Rad AG 1-X8 100200 mesh (4 mm i.d. × 4 cm h). Lead retained on the column was eluted with 6 M HCl after washing the column with 0.5 M HBr. The column yield of the purified solution was measured by 212Pb activity and then the solution was subjected to lead concentration measurement by GFAAS. Lead concentration in the sample was determined from the relationship between sample weights and total lead amounts obtained from more than 3 analyses of the same sample using the method of least-squares fitting. The lead values obtained for standard materials, JA-1, JB-1, JB-2, JB-3, JG-1, JGb-1, JR-1, JR-2 of GSJ rocks and of NIES SRM No.1 Pepperbush were 5.7, 7.3, 5.1, 5.7, 27.1, 1.6, 19.1, 23.7 and 5.3 ppm, respectively. Marine samples contained traces of lead: 27 ppb fresh weight for algae (Eisenia bicyclis), 96 ppb for abalone shell (Haliotis discus) and 4.5 ppb f.w. for abalone muscle.View full abstractDownload PDF (1191K) -
Morimasa SAITO1986 Volume 35 Issue 7 Pages 598-602
Published: July 05, 1986
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSRelative sensitivity coefficients(RSC)(Fe=1) of elements in steel, copper and aluminum standard samples when gold, platinum, silver, tantalum, tungsten and aluminum probes were used as counter electrodes were studied. The metal probe used was about 0.5 mm in diameter and the elements measured were B, Si, P, Ti, V, Cr, Co, Ni, Cu, As, Nb, Mo, Sn, Ta, W and Pb. The difference in the RSC values amoung the metal probes was found not to exist except for the elements of Ti, Si and Sn, and the RSC values obtained by the metal probe methods tend to be in good agreement with those obtained by the conventional method using the solid sample electrodes (the solid method). The precision of these methods except for the aluminum probe method was from 5 to 13% better than that of the solid method. However, these probe methods had the same matrix effects as the solid method. The precision for Si and Ti in steels was poor due to inhomogeneity of samples and also the poor precision of aluminum probe method seemed to be due to the instability of the spark caused by vigorous consumption of aluminum.View full abstractDownload PDF (924K) -
Yoshisuke NAKAMURA, Hitoshi YAMAGUCHI, Haruno OKOCHI1986 Volume 35 Issue 7 Pages 603-608
Published: July 05, 1986
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA hundred mg of a sample was dissolved with 10 ml of conc. nitric acid and 50 ml of the mixture of hydrofluoric acid and potassium fluoride(200 ml+30 g), the sample solution was then cooled to below 10°C to precipitate the potassium hexafluorosilicate. The precipitate was filtered using funnel cover in order to maintain a low temperature and then dissolved in a hot sodium nitrate solution(5w/v%). After the solution was adjusted to pH 78 with a sodium hydroxide solution(0.2 M), it was diluted to 500 ml with the sodium nitrate solution, and a 50 ml aliquot was exactly transferred to a polyethylene beaker(200 ml). Three ml of the total ionic strength adjustment buffer was added to adjust the pH of the solution to pH 5.35.4 and to promote the dissociation of the fluoride ion from hexafluorosilicate ion. The fluoride ions were titrated against a standard lanthanum nitrate solution (1/30 M). The analytical concentration range was 2080% of silicon. The recovery of silicon (Si : 20, 40, 60, 80 mg) when analyzing synthesized samples (molybdenum powder +standard solution of silicon) was 99.98±0.03% (n=5). The maximum permissible amounts of interfering elements in determining 40 mg of silicon were 2.0 mg for Al, 2.5 mg for Ca and 3.0 mg for Mg. However, the analytical values were not affected because molybdenum disilicide does not contain these element. The analytical value for ferrosilicon of Japanese Standards of Iron and Steel JSS 720-3(Si : 75.94%), was 75.94% (n=6, R. S. D. =0.054%). The analytical value of silicon in molybdenum disilicide was 36.64% (n=7, R. S. D. =0.065%), while the analytical result by the neutralization titration was 36.4% (n=7, R.S. D. =1.26%).View full abstractDownload PDF (987K) -
Makoto KIMURA, Keiichiro HOZUMI, Keisuke KITAMURA1986 Volume 35 Issue 7 Pages 609-613
Published: July 05, 1986
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDuring the low-temperature ashing of organic materials under the oxygen plasma, oxidant gases are excited by high frequency wave so as to yield their characteristic emission spectra. Nitrogen-containing organic materials were identified by the emission spectrum of N2 337.1 nm and the spectral intensity was dependent upon the nitrogen composition of the organic materials under a given plasma condition. A basic survey of the spectral intensity of the nitrogen gas showed that the electric power and the gas pressure were the essential plasma parameters controlling a reproducibility in the spectral intensity while the effect of gas flow rate was negligible. The present plasma condition under the electric power of 20 W and the gas pressure of 0.75 Torr gave a relative standard deviation of 0.36% as a reproducibility of the spectral intensity and a detection limit of nitrogen of 40 ppm when diluted by a helium carrier gas. Determination of nitrogen in the organic materials such as the amino form encountered, however, with difficulty because of different oxidation rate of the materials that changed the concentration of nitrogen in the oxygen plasma. An attempt was therfore made to standardize the spectral intensities of nitrogen by taking intensity ratios of N2 337.1 nm/CO 308.0 nm which were well proportional to the composition ratios of N/C in the organic materials. Several nitrogen-containing organic samples were successfully analyzed with the N/C ratios.View full abstractDownload PDF (748K) -
Yoshihito SUZUKI, Toshihiro INOUE1986 Volume 35 Issue 7 Pages 614-617
Published: July 05, 1986
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA high performance liquid chromatographic method has been developed for the fluorimetric determination of aliphatic nitriles. Nitriles in aqueous solution were converted to aliphatic amines by electrolytic reduction with the palladium attached on nickel gauze as a cathode. After the reduction, amines were subjected to react with 1-dimethylaminonaphthalene-5-sulfonyl chloride (DNS-Cl) in slightly alkaline solution at room temperature for 5 min. The fluorescent derivatives of amines were separated on Lichrosorb RP-8(15 cm × 4.6 mm i.d.) column with a mixture of methanol and water as binary mobile phase. The present method permits the detrmination of 20 ppm of aliphatic nitriles in aqueous solution.View full abstractDownload PDF (760K) -
Shigeru MONTANI, Kunio TADA, Tomotoshi OKAICHI1986 Volume 35 Issue 7 Pages 618-621
Published: July 05, 1986
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSPurines and pyrimidines are major chemical components of organisms. These bases are thought to play an important role on marine ecosystem and organic geochemistry. Therefore, cleanup procedures were developed for the determination of these bases in marine environmental samples. The separation and determination methods of uracil, thymine, cytosine, adenine, guanine and hypoxanthine were developed by HPLC using cation exchange mode. The present methods were rapid and convenient, as compared with those previously used. The data obtained as total purines and pyrimidines varied from 0.3 to 9.3 vg/l for suspended particles in seawater and 4 to 54 μg/g for sediment core samples obtained from Harima-Nada of Seto Inland Sea in Japan.View full abstractDownload PDF (522K) -
Katsuaki KAMETANI, Toshiro MATSUMURA, Masaaki SAKURAI1986 Volume 35 Issue 7 Pages 622-625
Published: July 05, 1986
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSAn analytical method for the determination of microgram quantities of iodine was developed by combining the procedure, which liberates six equivalents of iodine from the reaction of iodide and iodate ions produced from iodine in the sample solution, and the method of colorimetric determination of iodine using Leuco Crystal Violet. The proposed method is able to determine the microgram level of iodine and the relative standard deviation was 1.2% for the determination of 7.5 μg of iodine. In addition, the determination of iodine in suspended particles in air was tested, and it was found that the recovery of iodine from glass fiber filter was 82.8%. Furthermore, the determination of iodine in air at the ground surface in Tokyo was carried out, and the average value of iodine concentration in the suspended particles in 1000 m3 of air was found to be about 9.2μg.View full abstractDownload PDF (636K) -
Principle of the method and its applicationJunsuke SUZUKI, Tomihisa KAMBARA1986 Volume 35 Issue 7 Pages 626-628
Published: July 05, 1986
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA new technique, the iso-concentration analysis, has been applied to the spectrophotometry. Two series of aliquots are taken. In the first series, each aliquot contains the same amounts of the substance x= (x, x, …), to be taken to which an incremental amount of the standards is added as x +y = (x+y1, x+y2, …). The second series contains an α times amount of the standards added to the first series, y' (αy 1, αy2…). When all the aliquots of both series are made up to the same volume, V, the concentration of one of the aliquots in the first series is equal to that of second series. To all aliquots is added the constant amount of reagent which reacts with the species to be determined and forms the colored complex. The absorbance in any aliquot of the first and second series is given as Eqs.(1) and (2), respectively.
Ax+y=εkx+y(x+y)/V…(1)
Ay'= εky' αy/V…(2)
where Ax+y and Ay' are the absorbance. ε is the molar absorptivity, and kx+y and ky' are the constants. From both equations one obtains Eq.(3).
αi (kx+y/ky')(1+ (x /y)) =(kx+y/ky')(1 +xz) …(3)
where i =Ax+y/AAy', and z= 1/y. The plots of αi vs. z show an S-shape curve. All the curves of αi =f (z) have a common intersection at the point of kx+y= ky', which shows ik= 1. One obtains Eq.(4).
x=(α-1)/zk=(α-1)yk…(4)
The intersection point can be obtained as the intersection of the curve of αi=f (z) with αi=α. If α = 2, x is equal to yk, i.e., the amount of substance present in the sample can be determined without using a calibration curve. The method was successfully applied to the determination of antimony using a reaction with Brilliant Green.View full abstractDownload PDF (502K)
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