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Volume 37, Issue 12
Displaying 1-12 of 12 articles from this issue
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Osamu SETOKUCHI, Sadao MATUZAWA, Tadato YAMAMOTO, Yukio SIMIZU, Mituhi ...1988 Volume 37 Issue 12 Pages 637-641
Published: December 05, 1988
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA simple and rapid method has been developed for the gas chromatographic determination of trace amounts of formaldehyde. Formaldehyde is converted to hexamethylenetetramine, which is sensitive to hydrogen flame ionization detector, by the reaction with ammonia in a reaction column. The three-stage column, composed of a separation column, a protection column and a reaction column was used for the analysis. A glass column packed with Porapack N and Carbosieve G was used as a separation column. The glass columns packed with glass beads served as a protection column and a reaction column. After the separation of the formaldehyde sample was achieved in the separation column, formaldehyde reacted with ammonia introduced into the reaction column from the cylinder. The protection column was used to prevent the diffusion of ammonia into the separation column. A length of 30 cm for the reaction column gave the maximum response. The detection limit was 0.5 ng for formaldehyde, and the linear dynamic range was about 103. The relative standard deviation was 3.2% for 32 ng of formaldehyde.View full abstractDownload PDF (736K) -
Shoji MOTOMIZU, Naomi YONEDA, Tadashi IWACHIDO1988 Volume 37 Issue 12 Pages 642-647
Published: December 05, 1988
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSSodium and potassium ions were spectrophotometrically determined by solvent extraction flow injection incorporated with a silica gel column. The ion association complexes which formed between alkali metal-crown ether complexes and an anionic dye were extracted into an organic phase and the absorbance of the organic phase was measured after the phase separation by a phase separator with a poly(tetrafluoroethylene) porous membrane (pore size: 0.8 μm). Sodium and potassium were separated on a silica gel column (1 mm i.d. × 20 cm; 100200 mesh silica gel). Four streams, a carrier, an eluent, a reagent solution and an extraction solvent, were propelled at the flow rate of 0.8 ml min-1 The carrier was distilled water. The eluent contained 10-2 M lithium acetate and 5 × 10-3 M benzo-18-crown-6 (B18C6), and the reagent solution consisted of 5 × 10-4 M 4-diethylamino-2, 5-dichloroazobenzene-4-sulfonate, 5 × 10-3 M B18C6, 10-3M EDTA (dilithium salt) and 3 × 10-3 M lithium hydroxide. The extraction solvent was a mixture of benzene and chlorobenzene (1+1). The absorbance was continuously measured at 450 nm with a 8 μl flow cell (path length: 10 mm). Calibration curves for sodium and potassium were linear in the range from 1 × 10-4M to 2 × 10-3 M and from 5 × 10-6 M to 1 × 10-4 M, respectively. The sampling rate was about 20 samples per hour.View full abstractDownload PDF (726K) -
Yumie MAEDA, Kazuhiro OWADA, Masatoshi YAMAMOTO, Satoko SANO, Toshio M ...1988 Volume 37 Issue 12 Pages 648-653
Published: December 05, 1988
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA rapid, simple and reliable method was developed for the simultaneous determination of eleven corticosteroids, such as prednisolone, triamcinolone acetonide, fluocinolone acetonide, hydrocortisone butyrate, fluocinonide, difluprednate, dexamethasone valerate, betamethasone valerate, prednisolone valerate-acetate, beclomethasone dipropionate and diflucortolone valerate, and four parabens, such as methyl, ethyl, n-propyl and n-buthylparaben in ointments by HPLC. The method involves a clean-up on a disposable SepPak silicagel cartridge. Fat-soluble excipients are removed through the cartridges with 10 ml of hexane-chloroform (70 : 30). Corticosteroids and parabens are then eluted from the cartridges with 10 ml of ethyl acetate and determined by HPLC on a reversed-phase column with water-methanol (50 : 50 and 60 : 40) as the mobile phase, and detected at 240 nm with 0.04AUFS using s-butylparaben as an internal standard. The method was successfully applied to the analysis of ointement base spiked corticosteroids and parabens, and the sufficient recoveries (98.4103.2%) were obtained with relative standard deviation of 0.42.4%.View full abstractDownload PDF (889K) -
Akifumi YAMADA, Yutaka ARAKAWA, Yayoi OKUDA, Kazunori HODOUCHI, Koichi ...1988 Volume 37 Issue 12 Pages 654-658
Published: December 05, 1988
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSChloride in cement pastes was determined by using displacement reaction with silver chromate with chloride ions. The accuracy of the method depended on the pH value of the pretreated solution. A recommended procedure is as follows: Transfer a 1 ml aliquot of the cement paste solution and 1 ml 0.1 M (1 M = 1 ml dm-3) nitric acid to a 100 ml-volumetric flask. Add 5 ml 1 M acetic acid-ammonium acetate buffer solution and dilute up to the mark with distilled water. Add 200 mg silver chromate and shake the flask for 2 min. Filter through a No. 5C filter paper to remove excess silver chromate and silver chloride produced, and add 1 ml 4 M ammonia solution. Measure the absorbance of filtrate at 405 nm in 1 cm cells using a chloridefree blank, prepared by this same procedure in the reference cell. Linear relation was observed in chloride concentration range of 0.170 ppm. Thus, 0.3170 mM chloride in cement paste was determined with a relative standard deviation of 240% repeated runs.View full abstractDownload PDF (654K) -
Tetsuya HIROI, Kazuyuki OUCHI, Tsuneo OKUYAMA, Kohji NOGUCHI1988 Volume 37 Issue 12 Pages 659-664
Published: December 05, 1988
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSHydrophobic chromatography of proteins were studied with the polyvinylalcohol beads column (Aashipak GS 320 H, 7.6 mm i.d. × 250 mm), which was originally used for gel permeation chromatography. The kinds of proteins having the molecular weight range of 11000460000, were loaded on the column and eluted with 60 min-linear gradient from 50 mM Tris-HCl (pH 7.5) containing 1.6 M ammonium sulfate to 50 mM Tris-HCl (pH 7.5) containing 5% (v/v) acetonitrile at a flow rate of 1.0 ml/min. The relationship between logarithm of the molecular weight of proteins and the retention time was found to be linear, indicating that this method could be applicable to the separation of the proteins which have the molecular weight larger than exclusion limit (MW; 20000) of this column in the case of gel permeation chromatography. The recoveries of proteins were more than 90% in all the cases examined. Even α2-macroglobulin (MW; 800000) and immunoglobulin M (MW; 1000000) could be recovered with this procedure. We have concluded that the hydrophobic chromatography on polyvinylalcohol beads column could be a useful method for the analysis as well as for the preparative separation of various proteins of wide molecular weight range without denaturation.View full abstractDownload PDF (747K) -
Shigeru TANAKA, Kensuke YASUE, Nakaya KATSURA, Yoshimasa TANNO, Yoshik ...1988 Volume 37 Issue 12 Pages 665-670
Published: December 05, 1988
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA method for the determination of formic acid and acetic acid in rain water by ion chromatography was investigated. Three different methods were tested for formic acid and acetic acid determination. One is ion exchange chromatography (IC) by using Na2B4O7 solution as an eluent, and the others are ion exclusion chromatographys (ICE) with Ag+-type suppressor column and cation exchange fiber suppressor. The ion exchange chromatography by using 2 mM Na2B4O7 eluent was the most suitable method for formate and acetate ions determination from the viewpoint of the separation of these ions and the analytical sensitivity. This IC method could obtain a good separation of formate and acetate ions even in the case of sample volume as large as 1000μl, while the ICE methods could not obtain a good separation. The detection limits of the IC method were 0.003 ppm for formate ion and 0.005 ppm for acetate ion at 1000 μl injection volume. Forinate and acetate ions were eluted within 6 minutes by 2 mM Na2B4O7 eluent at 1.9 ml/min flow rate. Most of nitrate and sulfate ions in rain water were retained on the anion exchange resin of the separation column and could not be eluted by using 2 mM Na2B4O7 eluent due to its wesk elution ability. It is necessary to elute out these ions from the separation column in order to maintain a good reproducibility of the analysis. So, 4 mM Na2CO3/4 mM NaHCO3 solution was injected to the separation column with the injector after formate and acetate ions were detected, so that nitrate and sulfate ions were eluted out before the measurement of the next sample. It takes about 20 min to complete the analysis of a rain water sample by using the above method, and the relative standard deviation of the analysis was 3.7% for formate ion and 7.1% for acetate ion, respectively. The measurements of formic acid and acetic acid in rain water at Hiyoshi, Yokohama were done from April to October 1987 by this method. The concentration range was 0.05 0.91 ppm for formic acid and 0.040.56 ppm for acetic acid, respectively.View full abstractDownload PDF (1008K) -
Takashi OKAI1988 Volume 37 Issue 12 Pages 671-674
Published: December 05, 1988
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA rapid and accurate method for the determination of Zr in geological materials is presented. The interference of F- was reduced by masking with Al+, and Fe3+ was reduced to Fe2+ with hydrazinium dichloride. A sample (0.2 g) was decomposed with a mixture of HNO3, HClO4 and HF, and the solution was evaporated to dryness. Then the dried sample was fused with a mixture of 2 g Na2CO3 and 0.3 g H3BO3, and the melt was dissolved in 17 ml of HCl (1 + 1), and it was diluted to 50 ml with water. Fifteen ml portion of the sample solution was transferred to a 50 ml volumetric flask. To it, 8 ml of Al chloride solution (Al3+ 25 mg/ml) and 5 ml of hydrazinium dichloride solution (15 w/v%) was added. The solution was heated in boiling water for 15 min. After cooling, 5 ml of Xylenol Orange solution (0.1 w/v%) was added and diluted up to the mark with water. Absorbance was measured at 535 nm. Ten samples could be analyzed in 5 h. This method was satisfactorily applied to a variety of geological reference materials.View full abstractDownload PDF (681K) -
Mari TAKAHASHI, Kazuyoshi TAKIYAMA1988 Volume 37 Issue 12 Pages 674-676
Published: December 05, 1988
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSMagnesium is generally efficiently determined by AAS using any flame, but some foreign ions is known to interfere with the air-acetylene flame. In particular, a large quantity of Ca raises the response of Mg, while phosphate depresses it. When laurylpyridinium chloride (LPC) was added to Mg solution to reach 7.5 ×10-2 M, the atomic absorption of Mg was highly enhanced and the interference of Ca and/or phosphate was overcome. LPC decreases the surface tension of the solution, and then the sample uptake rate is increased and the spray droplet is decreased. So, the sensitivity of Mg absorption is increased. Enhancement effect of LPC may also be attributed to the reducing action of the CN radical formed in the flame by decomposition of LPC. Mg in several foodstuffs could be efficiently determined by the present method.View full abstractDownload PDF (447K) -
Hiromiti SAWAMOTO, Miwa KAWAZOE1988 Volume 37 Issue 12 Pages 676-678
Published: December 05, 1988
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDL-Thioctic acid (α-lipoic acid) is adsorbed on a mercury electrode in the potential region more positive than ca. -0.4 V vs. SCE and yields a reduction peak at ca. -0.6 V. The adsorption of thioctic acid is employed in the preconcentration step of the stripping voltammetry of thioctic acid (adsorptive stripping voltammetry). From the fundamental studies it was found that in 0.1 M ammonium acetate the stripping peak height for thioctic acid was maximum. The optimal preconcentration potential, preconcentration time, scan rate and temperature are -0.2 V, 5 min, 50 mV/s and 25 °C, respectively. Under the optimum conditions described above, the calibration curve is linear up to 1.6 μM and the detection limit is 0.1 μM. Thioctic acid and riboflavin in milk were determined by this method.View full abstractDownload PDF (529K) -
Toru MITOMO, Mitsunojo ICHISE, Tsugio KOJIMA1988 Volume 37 Issue 12 Pages T223-T227
Published: December 05, 1988
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSUV-excited resonance Raman spectroscopy has a potantial as a method for highly sensitive and quantitative analysis of organic molecules in acqueous solution. In its application to flow analysis and liquid chromatography, a "rapid measurment" and a "very small sample size" are essential. In this paper, multichannel detection of the single UV pulse-excited resonance Raman spectra was investigated. Excitation by a single laser pulse (347 nm, 22 ns, 20 mJ) gave well-resolved resonance Raman spectra of t-azobenzene, p-aminoazobenzene and p-aminobenzophenone, which showed 3000 cm-1 shift with resolution of 18 cm-1. The emittance gain of image intensifier should be at least 2 × 104 w/w for these measurements. Considering from the characteristics of optical systems and the above results, measuring conditions for a single pulse excitation of at 200 nm were discussed.View full abstractDownload PDF (776K) -
Zou JUN, Mitsuko OSHIMA, Shoji MOTOMIZU1988 Volume 37 Issue 12 Pages T228-T231
Published: December 05, 1988
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSSimple and highly sensitive method of boron determination in steels and iron salts has been studied. Boric acid forms a complex anion with chromotropic acid in an aqueous solution. The complex anion and excess of chromotropic acid were separated by HPLC with anion exchange column (TOSO TSK gel IC-Anion-PW). Octyltrimethylammonuim chloride was added to accelerate the complex formation. The eluent solution consisted of 0.2 M sodium perchlorate and 1 × 10-3 M acetate buffer solution (pH 5.6). Steel sample solutions were prepared as follows: weigh 0.1 g of a steel sample into a 100-ml fused silica beaker and add 2 ml of 2.5 M sulfuric acid. Add 1 or 2 ml of 30% hydrogen peroxide solution gradually, heating the solution moderately. After dissolving, continue heating modelately to remove the excess of hydrogen peroxide. Then boil the solution for 1 min. Transfer to a 100-ml of measuring flask made of polyethylene and make up to the mark with water. For each 60 ml of these solutions, add 15 ml of 1 M EDTA solution and neutralize to pH 4 with 1 M sodium hydroxide. Then make up to 100 ml. Standard procedure was as follows: transfer 10 ml or less of the sample solution to a test tube made of polypropyrene, if nesessary, add water up to 10 ml. Add each 0.5 ml of the reagent solution(A) which consists of 1.6 × 10-2 M disodium chromotropate and 0.1 M EDTA solution and the reagent solution(B) which consists of 2 M octyltrimethylammonium chloride and 1 M acetate buffer solution (pH 4.8). After standing for 60 min, inject 10 μl of the solution to the HPLC and measure the absorbance at 350 nm. Boron in iron salts was determined in similar manner. Interference from iron up to the concentration of 5× 10-2 M was eliminated with EDTA solution. The detection limit was 0.006μg/m1 of boron. The sampling rate was 17 samples/h.View full abstractDownload PDF (522K) -
Extension of linear range of calibration curveTetsuo UCHIDA, Hirofumi ISOYAMA, Mariko TATEMATSU, Isao KOJIMA, Chuzo ...1988 Volume 37 Issue 12 Pages T232-T237
Published: December 05, 1988
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe simple modification of the circuit in AAS for an average of absorption signals readily permitted the integration of signals (measurement for total area of signals). This made the absolute amount measurement easily feasible, because in "one-drop method" the peak area was directly proportional to the mass of the analyte in the solution injected. Thus, the linear range of calibration curve could be apparently extended both to lower and to higher concentrations only by the increase or decrease in the volume of sample solution injected. Changing of operating conditions of AAS, such as scale expansion or burner angle and re-pre paring sample and/or standard solution did not need. The present technique would be particularly convenient for routine analyses of practical samples, because a few samples might deviate from the available range of the calibration curve in use. The present method was successfully applied to the determinations of Cu, Mg and Mn in NIES-CRM No. 1, Pepperbush.View full abstractDownload PDF (893K)
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