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Volume 41, Issue 7
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Akihiro ONO1992 Volume 41 Issue 7 Pages 289-308
Published: July 05, 1992
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSImprovement in quality and productivity, and expansion in the variety of steel products have generally been followed by development of automated and rapid analytical methods for production control use. I have been engaged in research work on (1) automation of wet chemical methods and (2) development of on-line real time instrumental methods. Fully automated analytical methods have been developed based on automation of such unit procedures as sample dissolution, distillation, spectrophotometric measurement for determining small amounts of P, Si, Mn, Al, N and B in steel samples, and for determining Fe(II) and Fe(III) ions in Zn-Fe galvanizing solution as well. These achievements proved to not only shorten analysis time and save labor but also improve the precision and accuracy of the analytical methods. On-line real time analytical methods have also been developed for determining elements in molten metal by utilizing several means such as measurement of emission spectra from “hot spot” formed by blowing oxygen onto molten iron in converter, measurement of ICP emission spectra from ultra-fine particles generated from molten steel by gas atomization, and gas chromatographic measurement of collected hydrogen by bubbling Ar gas in molten steel. For example, the Mn content in molten iron can easily be obtained continuously in 15 s intervals without a sampling procedure by measuring the emission spectra from “hot spot”.View full abstractDownload PDF (3021K) -
Toshiaki NOMURA, Kazutake TAKADA, Toshiyuki MITSUI1992 Volume 41 Issue 7 Pages 309-315
Published: July 05, 1992
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSWhen one of the leading wires from an oscillator to a piezoelectric quartz crystal was cut off and then the cut parts (electrodes) were immersed in a solution, the crystal oscillated and the frequency of the crystal having the electrodes immersed in the electrolyte solution shifted with the conductivity and that in organic solvents shifted mainly with the permittivity. The frequency changes of the crystal having wire electrodes immersed in the electrolyte solutions were proportional to the conductivities and increased with decreasing distance of the electrodes. The crystal, therefore, could be used to the conductivity or permittivity detector. The crystal having the wire electrodes was used for the detectors of liquid chromatograph and titrations.View full abstractDownload PDF (880K) -
Nobumasa ARAI, Hiroaki MINAMISAWA, Osamu HIROTA, Tadao OKUTANI1992 Volume 41 Issue 7 Pages 317-322
Published: July 05, 1992
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSBi(III) complex having the composition of Bi(III)-2, 4, 6-tri-2-pyridyl-1, 3, 5-triazine (TPTZ)-ClO4-=1 : 2 : 3 is extracted into nitrobenzene easily. The Bi(III) in the resulting organic phase can be determined by flame AAS. The optimum pH range for the extraction of Bi(III) complex was 2.03.5. The calibration curve was linear below Bi(III) 80.0 μg/200 cm3 (aqueous phase). Relative standard deviations (n = 10) were 2.3% for 50 ppb Bi(III). Determination limits (S/N≥3) were 5 ppb for Bi(III). Interference of Sn(II), Ti(IV) and Fe(III) with the determination of Bi(III) could be masked by adding 0.1 mol dm-3 ammonium fluoride. The resulting determinations of Bi(III) in water and seaweeds were satisfactory. The composition of the extracted complex was [Bi(TPTZ)23+(ClO4-)3]. Based on the distribution equilibrium quations for extraction, the extraction constant (Kex), the distribution coefficient (Kd), and the formation constant (β) of this complex were 6.06×1012, 5.49×102and 1.10×1010, respectively.View full abstractDownload PDF (712K) -
Yoshihito SUZUKI, Mingyu DING, Hitoshi KOIZUMI, Kazue TANI1992 Volume 41 Issue 7 Pages 323-329
Published: July 05, 1992
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe effect of a suppressed system on the sensitive and selective detection of analytes in ion chromatography was investigated using organic acid eluents of low conductivity. The separation of organic acids was carried out on a chemically bonded hydrophilic anion-exchange column (SAM column, 4.9 mm i.d. × 75 mm) fitted with a conductivity detector and using 2.5 mM potassium biphthalate (pH 4.15) as eluent. Chemically suppressed conductivity detection was accomplished using a cation-exchange micro membrane tube which was continuously regenerated with 15 mM sulfuric acid. Chromatograms of organic acids presented positive peaks without suppressed system under the above chromatographic conditions. When the suppressed system was used, however, acetic, lactic, succinic, malic and tartaric acids indicated negative peaks, and the detector response showed higher sensitivity than without the suppressed system. But the chromatograms obtained with and without the suppressed system when 2.5 mM phthalic acid (pH 2.90) was used as the eluent were the same. Since the background conductivity of potassium biphthalate eluent in the detector increased and the relative conductivity between analyte and eluent varied when the suppressed system was used, the detector response had changed. This situation resulted in negative peaks for organic acids which have lower conductivity than phthalic acid. The negative peak height increased linearly with increasing injection amounts. Oxalic acid eluent adjusted to around pH 4 resulted in negative peaks both with and without the suppressed system. On the other hand, succinic acid eluent, pH 4, gave only positive peaks. This explains the high background conductivity of oxalic acid and the low one of succinic acid. The detector response changed when the background conductivity of the eluent was greatly varied by suppressed system.View full abstractDownload PDF (777K) -
Yasuyuki MIURA, Tomozo KOH1992 Volume 41 Issue 7 Pages 331-335
Published: July 05, 1992
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe separation of iodide from sulfate, perchlorate, thiocyanate and thiosulfate, all of which are generally late-eluting anions, was investigated using phosphate, tartrate, phthalate and 1, 3, 5-benzenetricarboxylate (BTC) as eluents in suppressed ion chromatography with a silica based anion exchange column (TSKgel IC-Anion-SW). The flow rate of the eluents was maintained at 1.0 ml/min and a conductivity detector was used. Of the four eluents, BTC solution was the most powerful in both the lowest concentration and the lowest background conductivity. When 1.5×10-4 M BTC eluent (pH 6.0) was used, iodide was eluted out within 8 min and separated completely from mixtures containing phosphate, nitrate, sulfate, thiocyanate, thiosulfate and dithionate. The high sensitivity of conductivity for these anions was achieved by using an anion micro membrane suppressor (AMMS), even when an acidic BTC eluent was used. When a 50-μl aliquot of sample solution was injected, the calibration graph plotted as peak height vs. concentration of iodide was linear up to 1×10-4 M. The observed detection limit for iodide as S/N=3 was 3.0×10-7 M (38.1 ppb). The proposed method proved to be applicable to the determination of iodide in various medicines.View full abstractDownload PDF (618K) -
Katsuaki KAMETANI, Toshiro MATSUMURA, Mitsuhiro NAITO1992 Volume 41 Issue 7 Pages 337-341
Published: July 05, 1992
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSAnalytical methods for the determination of iodide and iodate ions in surface water were investigated. Iodide in water was adsorbed on an anion exchange resin column and eluted as iodate which was then oxidized with permanganate. For the colorimetric determination of iodide, the Leuco Crystal Violet method was adopted. To obtain the concentration of iodate in surface water, total iodine was determined by a similar analytical method after reducing iodate to iodide with sulfurous acid. The concentration of iodate was calculated by subtracting the concentration of iodide from that of total iodine. The concentration of total iodine was 2.5 μg/l in rain water and 57 μg/l in river and tap waters. The analytical results of iodide and iodate in rain and river waters showed that the ratio of iodate to iodide in river water was higher than that in rain water. On the other hand, the analytical results for tap water showed that its ratio of iodate to iodide was conspicuously higher than that of river water.View full abstractDownload PDF (501K) -
Kazuo MURAKAMI, Michiko KAKEMOTO, Toshikatu HARADA, Yoseph YAMADA, Hir ...1992 Volume 41 Issue 7 Pages 343-348
Published: July 05, 1992
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSGlucose was determined by reacting it with glucose oxidase (GOD) to produce hydrogen peroxide which was then quantified electrochemically. Maltose was converted to glucose with glucoamylase (GAM) for determining subsequently. GOD and GAM were immobilized on controlled-pore silica beads and packed into a short stainless steel column. The effects of pore size of immobilized silica bead surface on the response were studied over the range 1001000Å Å. Maximum responses of glucose and maltose were obtained when pore size of that were 500 Å Å. The sensitivity of this detection system was nearly the same as that of chemiluminescence and about 5×102-fold that of differential refractive index method. The least detectable amounts of glucose and maltose were 10 ng and 15 ng (S/N=3), respectively. The use of specific enzymatic reaction and the electrochemical detector made sample pretreatments extremely simple. This system was successfully used to determine glucose and maltose in foods.View full abstractDownload PDF (685K) -
Yoshinobu AKADA, Nobuyuki ISHI, Yoshito NAKANE1992 Volume 41 Issue 7 Pages 349-351
Published: July 05, 1992
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDetermination of berberine chloride in pharmaceutical preparations was investigated by capillary electrophoresis. Free zone capillary electrophoresis in phosphate buffer at pH 5.0 gave complete separation of berberine from accompanying substances within 20 min. A sample solution was introduced by hydrostatic method and the on-column detection was performed at 214 nm. The calibration curves of berberine chloride gave good linearity over the concentration range of 10100 μg ml-1. Berberine chloride in various preparations was determined with good reproducibility.View full abstractDownload PDF (302K) -
Nobuo NAKANO, Yosio KOBAYASI, Kunio NAGASHIMA1992 Volume 41 Issue 7 Pages T97-T102
Published: July 05, 1992
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA porous cellulose tape coated with a silica gel as the absorbent and impregnated with a coloring solution which includes silver nitrate, p-toluenesulfonic acid, glycerin and methanol is a highly sensitive means of detecting hydride gases such as phosphin and arsine and is stable upon exposure to light. The hydride gas, adsorbed on the surface of the tape, reacted with the silver nitrate to form a stain the intensity of which could be measured by an optics system to determine the concentration of the gas. A linear relation was obtained between sampling time and relative intensity in the range of 0.01 to 0.05 ppm of arsine at a constant flow rate of sample gas. The detection limit was 0.01 ppm for arsine at a sampling time of 20 s and flow rate of 350 ml/min. This method is hardly affected by other gases excepting hydrogen sulfide. This tape maintains a white background for at least six months under normal storage conditions at room temperature with protection from light and maintains mechanical strength for at least twelve months.View full abstractDownload PDF (2044K) -
Etsu YAMADA, Kenji NAGAOKA, Toyohide TAKEUCHI, Hisayoshi IKATSU, Chie ...1992 Volume 41 Issue 7 Pages T103-T108
Published: July 05, 1992
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA round robin test between seven universities was carried out for the determination of total cyanide in complicated wastewater samples by Japanese Industrial Standards and other analytical methods. Six kinds of waste samples obtained from university laboratories and a tap water sample were prepared. Relative standard deviation of the analytical data for these samples by the Japanese official method were within ±10%. Interference of organic compounds, residual chlorine at low concentration or sulfide on the total cyanide determination was eliminated by the addition of ascorbic acid or zinc acetate at distillation. However, in the presence of residual chlorine at high concentration, recovery of total cyanide was only 4050% even by ascorbic acid addition and moreover cyanide ion was formed by the addition of hydroxylamine hydrochloride. It was found that cyanide compounds such as NH4Fe[Fe(CN)6] which are not easily decomposed, can be analyzed quantitatively by an increase of EDTA addition by three times at distillation.View full abstractDownload PDF (722K)
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