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Volume 46, Issue 2
Displaying 1-15 of 15 articles from this issue
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Yutaka YONEDA, Masako TAKAHASHI, Takashi KITAMURA1997 Volume 46 Issue 2 Pages 89-94
Published: February 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA determination method of amino acids in a dried blood disc for a neonatal mass-screening test was developed. The method consists of extraction with a 4mM sodium borate aqueous solution from a dried blood disc treated with methanol-acetone (1: 1) and an on-column fluorometric derivatization. High-performance liquid chromatography was performed isocratically using an acetonitrile-4 mM sodium borate aqueous solution (14.6: 85.4, v/v) containing 2 mM o-phthalaldehyde and 2 mM N-acetyl-L-cysteine as a mobile phase. Amino acids (i.e. Tyr, Val, Met, Ile, Orn, Phe, Leu, Lys) and methylhistamine as an internal standard were eluted within fifteen minuits with excellent reproducibility.View full abstractDownload PDF (1146K) -
Masashi GOTO, Kazuya TANAKA, Yukihiro ESAKA, Bunji UNO1997 Volume 46 Issue 2 Pages 95-100
Published: February 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSCapillary zone electrophoresis was employed to rapidly separate sugars, sugar alcohol, and sugar acids according to their electrophoretic mobilities in a strong alkaline solution containing a cationic surfactant, cetyltrimethylammonium chloride. Sample zones were monitored electrochemically using amperometric detection at a constant potential of 0.7 V (vs. Ag/AgCl) with a copper-disk microelectrode (30 μm in diameter). The copper microelectrode in strong basic solutions with a cationic surfactant showed about two-times the electrocatalytic oxidation currents for carbohydrates and related compounds compared to those without a cationic surfactant. A sample mixture of carbohydrates and related compounds was separated in less than 15 min, being one third compared with that of the conventional method. The detection limits for the samples studied were about 2.5 f mol (S/N=3), being about one twentieth compared with that of the conventional method.View full abstractDownload PDF (1350K) -
Ken MATSUMOTO, Mayumi YUNO1997 Volume 46 Issue 2 Pages 101-105
Published: February 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA simple and rapid method for the decomposition of refractory tungsten compounds has been proposed. The tungsten samples (WO3, WS2, WC, alloys and ores) were de-composed by fusion with ammonium hydrogen sulfate, which was found to be a suitably powerful flux for dissolving various refractory tungsten compounds. An accurately weighed sample (ca. 4050 mg) was placed in a dry Pyrex glass test-tube (16 mm o.d., 180 mm length). Ammonium hydrogen sulfate (ca. 2 g) was added to the tube and mixed with the sample by agitating of the tube. The bottom of the test tube was gently heated with a swirling motion over a small gas flame of a Bunsen burner with a fish-tail at a temperature of ca. 350450°C. Heating was continued until a clean, translucent yellow melt was formed. The cooled melt was dissolved in a 10% (w/v) ammonium tartrate solution. Tungsten(VI) oxide and sulfide were dissolved by heating for about 4 min, for carbide it was about 8 min. Finally, the concentration of the tungsten in the, resulting solution was determined by atomic-absorption spectrometry using a dinitrogen oxide-acetylene flame. This method was applied successfully to various hard metals and ores (scheelite). The tungsten, cobalt and iron in the samples were determined.View full abstractDownload PDF (1223K) -
Shigeru TAGUCHI, Atsushi KAKINUMA, Xia MIN, Issei KASAHARA1997 Volume 46 Issue 2 Pages 107-111
Published: February 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA simple and rapid preconcentration and spectrophotometric method was proposed for the determination of trace thiuram in water using a solvent-soluble membrane filter. Less than 80 μg of thiuram in 500 cm3 of a sample solution acidified with sulfuric acid was converted into a light-yellow complex in the presence of a large excess of copper (II) and ascorbic acid at pH 6. The complex was retained rapidly and quantitatively on a cellulose nitrate membrane filter by filtration under suction. The filter was quickly dried with a hair dryer and dissolved in 3 cm3 of 2-methoxyethanol which contained a small volume of concentrated sulfuric acid. The solution was heated with a hot-water bath for about 30 s. The color of the complex became deep-yellow showing an absorption max-imum at 390 nm. The absorbance of the solution was measured at the absorption max-imum against a reagent blank. Beer's relationship was obeyed over the concentration range from 50 to 160 μg dm-3 of thiuram. The detection limit was 1 μg dm-3 for three-times the standard deviation of the blank basis. High concentrations of Ca2+, Mg2+ Na+, K+, Al3+, Cl-, SO42 and NO3-, and sub-mg dm-3 levels of Fe3+ did not inter-fere with the determination. The recoveries of thiuram added to river water and ground water were satisfactory.View full abstractDownload PDF (1171K) -
Wataru YOSHIMURA, Atushi UZAWA1997 Volume 46 Issue 2 Pages 113-116
Published: February 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSCadmium in natural water was determined by means of coprecipitation with zirconium hydroxide and differential pulse anodic stripping voltammetry. Fifty milliliters of a sample solution were added to constant amounts of cadmium standard solutions. After 1 ml of a zirconium oxychloride solution was added, the pH was adjusted to 9.0 with ammonia water (1 : 2). The precipitate was separated by filtration and then dissolved in 25 ml of 4 mol dm-3 hydrochloric acid. This solution was diluted to 50 ml with distilled water. A portion of this solution was employed for determining cadmium. The results were as follows : 1) Zirconium hydroxide was the most effective collector of cadmium when the pH was adjusted to 9.0 with ammonium water (1 : 2). 2) Cadmium took about 90 min to be determined by this analytical procedure. 3) This method is applicable to the determination of trace amounts of cadmium in natural water.View full abstractDownload PDF (629K) -
Shinobu NAGA, Chieka NAGAI, Izumi NAGASHIMA, Hisashi KOIKE1997 Volume 46 Issue 2 Pages 117-120
Published: February 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSChlorpheniramine maleate (CPM) in tablet (CPM-T), powder (CPM-P) and injection (CPM-I) forms according to The Japanese Pharmacopoeia Thirteenth Edition (JP-XIII) was determined by the two-phase photometric ion-pair titration (TPPIT) method using Methyl Orange (MO) as the titrant. Ten ml of a buffer solution (pH 5) and 40 ml of dichloromethane (DCM) were added to a sample containing about 0.5 mg CPM and titrate in a 1 × 10-3 M MO standard solution; the solution was then stirred for 2 minutes. After the solution was separated into two layers, the absorbance of the DCM layer was measured at 425 nm. By repeating this operation, a titration curve was prepared and the titration end point was obtained. The amount of CPM was calculated, and compared with that determined by the JP-XIII method. No significant difference was found in the accuracy between the two methods. Therefore, the TPPIT method is a useful method for the determination of CPM.View full abstractDownload PDF (759K) -
Yuji SHIRAI, Shigetaka SUZUKI, Hiroshi HIBINO, Toshiaki HAYAKAWA1997 Volume 46 Issue 2 Pages 121-130
Published: February 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSAn analytical method for organophosphorus pesticides in feed was established by capillary column gas chromatography. After water was added to a sample, the pesticides were simultaneously extracted with acetonitrile. The extract was purified with a gelpermeation chromatograph on a stainless-steel column (20 mm i.d. X 300 mm), followed with a Florisil cartridge or a charcoal activate cartridge. The pesticides were simultaneously determined by a gas chromatograph equipped with a FPD on a fussed silica capillary column bonded 5% diphenyl 95% dimethyl polysiloxane or trifluoropropylmethyl polysiloxane (0.25 mm i.d. × 300 mm, 0.25 μm film tiness). The recovery test was conducted with mixed feed and hay (alfalfa) spiked with pesticides at levels of 0.022.0 ppm. Except for metamidophos and tiometon, the mean recoveries at levels of more than 0.02 ppm were in the range of 73119%, and the relative standard deviation of repeatability (RSDr) was within 14%. A cross check test was carried out at 3 laboratories with mixed feed spiked with the pesticides at levels of 1.0 ppm. The mean recoveries were in the range of 80129%, and the relative standard deviation of reproducibility (RSDR) was within 20%.View full abstractDownload PDF (1952K) -
Kusuo NARITA, Mituo UCHIDA, Kazuhisa SAKAKIBARA, Norio KAWAHARA, Yoshi ...1997 Volume 46 Issue 2 Pages 131-135
Published: February 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSIt was studied whether micro balances can work properly and show accurate weighing results under a strong magnetic field. Although a nuclear magnetic resonance device (NMR) generates a very strong magnetic field, it is generally operated by the constant a power of a magnet. In the surroundings of a NMR device, electronic micro balances have shown accurate weighing results as long as they were properly operated and calibrated before use. In the case of mechanical micro balances, although a few μg changes were observed, they were correctable by calibration before use. At a place near to the mass spectrometer (MS), which always changes its magnetic power, micro balances showed slight changes in the weighing results. However, accurate weighing results were confirmed as long as a certain distance from the MS was maintained. Other disturbances caused by the magnetic field were observed while handling or moving a magnetic substance near to the micro balances. In such cases, a significant change in the weighing results or unstable results was observed.View full abstractDownload PDF (990K) -
Osamu HAMAMOTO, Masaharu TAKABATAKE, Shunichi UCHIYAMA, Toshiyuki HOBO1997 Volume 46 Issue 2 Pages 137-142
Published: February 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSSmall pieces of filter paper (10 mm × 10 mm) with various reagents were employed as sample absorbing mats for rapid portable coulometric analyses. Samples were absorbed by the mats, and placed between the electrodes to be analysed by constant-voltage coulometry. Vitamin C in lemon juice was determined by a direct electrolysis of the sample absorbed in the mats. The results showed an excellent agreement with those by the indophenol method; the precision was within 2.0% in the relative standard deviation. Hydrogen peroxide was determined using a mat with potassium iodide. The enzyme dispersed in the mat was also tested for the determination of D-glucose. A mat pregnant with glucose oxidase and potassium iodide was employed for this application; a similar result to that in the coulometric analysis of sample injection method with pipettes was obtained. The sample-absorbing mats can be expected to offer a practical sampling method and sample pre-treatment measurements for rapid coulometry.View full abstractDownload PDF (1268K) -
Masahiro MIYASHITA, Saburo YAMASHITA1997 Volume 46 Issue 2 Pages 143-148
Published: February 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThis paper describes the anion-exchange solid-phase extraction of iodide ion (I-) using a column (Bond Elut® NH2) packed with aminopropylsilyl bonded silica. The quantitative retention of I- on the solid phase in the free (-NH2) form is obtained when the pH of the sample is adjusted below 5.0, while on the solid-phase in the acetate form it is obtained below 6.7. The I- retained on the solid phase is effectively eluted with ammonia water. To eliminate the analytical interference from ammonium ion, I- eluted from the solid phase is passed through a cation-exchange column packed with AG® 50W-X8, and is then subjected to reversed-phase HPLC with a UV detector. In the optimum extraction procedures, the recoveries of. I- from 1, 0.1 and 0.01 mM I- standard solutions (0.5 ml) were 98.3 ± 1.8, 92.9±2.0 and 88.0±3.5%, respectively.View full abstractDownload PDF (1263K) -
Hiroshi KAWAMOTO, Yoshikatsu TAKAZAWA, Hiroki YANAGI1997 Volume 46 Issue 2 Pages 149-151
Published: February 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe partition coefficients of pyridine between an organic solvent and the aqueous phase were rationalized by using the newly-proposed equation, which was derived on the basis of the concept of regular solution theory.View full abstractDownload PDF (490K) -
Hiroshi ONO, Noriko KANKE, Nobuo UEHARA, Tokuo SHIMIZU, Yoshio SHIJO1997 Volume 46 Issue 2 Pages 153-158
Published: February 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe separation and simultaneous determination of trace amounts of Cu, Ag, and Cd in high-purity Zn were studied. After the sample was dissolved in a mixture of sulfuric acid and nitric acid, Cu, Ag and Cd were separated from Zn by extraction into xylene as diethyldithiocarbamates complexes using diethylammonium diethyldithiocarbamate (DDDC), and then back-extracted into nitric acid for a determination by ICP-AES. The recoveries of Cu, Ag and Cd were satisfactory throughout the extraction with 2.5 × 10-2 mol/l DDDC in xylene from 0.25 mol/l sulfuric acid-0.1 mol/l nitric acid solution and the back-extraction with 7.5 mol/l nitric acid. The extractions of Cu, Ag and Cd were sup-presed in the presence of hydrochloric acid. The diverse elements in Zn caused no interference for the determination of Cu, Ag and Cd. The recoveries of Cu, Ag and Cd decreased somewhat with increasing the added amount of Zn. Thus, the standard addition method should be applied for the determination of these metals. The detection limits were found to be 0.17 μg/g for Cu, 0.12 peg for Ag and 0.07 μg/g for Cd using 1 g of a Zn sample. The proposed method was applied to an analysis of the reference material, the results agreed with the certified values.View full abstractDownload PDF (1199K) -
VI. A report on a third round-robin testM. NAGATA, S. MORI, Y. GOTO, M. YABE, K. TAKADA, N. OOSHIMA, H. OOZEKI ...1997 Volume 46 Issue 2 Pages 159-166
Published: February 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA third round-robin test of three polystyrene samples by size-exclusion chromatography (SEC) was performed at seven laboratories using the same SEC columns under the same experimental conditions of the second round-robin test. After rejecting suspected results of one laboratory, the relative standard deviations (RSD) of the number-average molecular weight (Mn) were between 7.4 and 11 %, and those of the weight-average molecular weight (Mw) were between 2.6 and 3.4%. These values can be regarded as the RSD of the molecular-weight averages obtained at different laboratories using the same columns under the same experimental conditions. A recalculation of the chromatographic data obtained at seven laboratories by the same person using the same data processor gave better RSD values of Mn as 2.36.1% including the suspected data. The use of the same data processor operated by the same person was capable of a standardization of the determination of the baseline and the cutoff molecular weight, which resulted in an improvement in the RSD of Mn. A careful determination and data processing can decrease RSD to these values. Magnification of chromatograms on the data processor makes the determination of the baseline easy, and can give the precision and accuracy of the detector used.View full abstractDownload PDF (1567K) -
Kumiko OHTSU1997 Volume 46 Issue 2 Pages 167-168
Published: February 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDownload PDF (443K) -
1997 Volume 46 Issue 2 Pages e1
Published: 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDownload PDF (114K)
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