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Volume 47, Issue 8
Displaying 1-10 of 10 articles from this issue
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Osamu SHIROTA, Yutaka OHTSU1998 Volume 47 Issue 8 Pages 465-472
Published: August 05, 1998
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSAttempts to miniaturize columns for liquid chromatography (LC) have been reported since the late 70's. A series of advantages were repeatedly claimed in the use of microcolumns, whose inner diameters were less than 1 mm. However, several requirements and limitations have kept microcolumn LC within a very limited area of applications. On the contrary, semi-microcolumn LC (inner diameter: 12 mm) has been widely accepted in academia and industry, possessing both advantages shown by microcolumn LC and the reliability of conventional LC. Although certain modifications, such as miniaturizing dead volumes of components, are required in instrumental arrangements, it became possible to easily obtain highly efficient separation with a semi-microcolumn, even under isocratic conditions. The benefits of semi-microcolumn LC seem most pronouncing when a column-switching system is arranged. A tremendous concentrating effect could be earned by first injecting a sample solution into a short conventional-bore precolumn, and then transferring an analyte-containing fraction to a semi-microcolumn connected into a detector. This analytical format was applied to the analysis of various substances contained in biological liquids at very low concentrations. The later sections of the article discuss some of these applications, including forensic analysis and diagnosis in clinical chemistry.View full abstractDownload PDF (1380K) -
Hideo NOGUCHI, Shigeaki MATSUTANI, Shoichi TANAKA, Yasunobu HORIGUCHI, ...1998 Volume 47 Issue 8 Pages 473-479
Published: August 05, 1998
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSAn alkyl homologue distribution analysis of surfactants contained in household detergents or toiletries involved intricate work. A rapid analysis method using a two-dimensional (2D) HPLC has been developed. In the case of anionic surfactants, each surfactant, such as carboxylates or sulfates, is separated from matrices according to the type of anionic group by an anion exchange column (1D), and eluted as a single peak. The eluted surfactant is trapped on a C8 short column and then transferred to a C18 analysis column (2D) by a switching technique. The alkyl homologs can be analyzed in this a time of less than 40 min. In the case of cationic or amphoteric surfactants, a cation exchange column was used as an 1D column. The method was successfully applied for the analysis of carboxylates, sulfates, sulfonates, quaternary ammonium salts, alkyl pyridinium salts, amidobetains, and other surfactants in household formulations.View full abstractDownload PDF (978K) -
Akiko TANABE, Hideko MITOBE, Kuniaki KAWATA, Masaaki SAKAI1998 Volume 47 Issue 8 Pages 481-489
Published: August 05, 1998
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA gas chromatography-mass spectrometry (GC/MS) was applied to the determination of 90 pesticides and 10 transformation products in the particulate matter (PM) of river water. The pesticides investigated were 18 fungicides, 30 insecticides and 42 herbicides. After a water sample was filtered through a glass-fiber filter (1 μm of pore size), the filtrate was filtered with a hydrophilic polytetrafluoroethylene (PTFE) filter (0.5 μm of pore size). The target compounds on the PM on each filter were extracted ultrasonically with acetone. The extracts were concentrated under reduced pressure for GC/MS determination. The overall recoveries of the compounds were 74% to 104% from PM. Thirteen compounds, such as etofenprox, benfluralin and trifluralin, spiked to a riverwater sample distributed to the PM at rates from 4.0 to 72%. This method has been successfully applied to monitoring compounds in river water.View full abstractDownload PDF (1218K) -
Ken MATSUMOTO, Mayumi KITAGAWA1998 Volume 47 Issue 8 Pages 491-495
Published: August 05, 1998
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA simple and rapid method for the decomposition of refractory cerium compounds has been proposed. Cerium samples (CeO2, CeTiO4, CeZrO4 and ore) were decomposed by fusion with ammonium hydrogen sulfate, which was found to be a suitably powerful flux for dissolving various refractory cerium compounds. An accurately weighed sample (ca. 30100 mg) was placed in a dry Pyrex glass test-tube (16 mm o.d., 180 mm length). Ammonium hydrogen sulfate(ca. 3 g) was added to the tube and mixed with the sample by agitating the tube. The bottom of the test tube was gently heated along 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 the yellow melt changed into a colorless, clear and translucent form. The cooled melt was dissolved in water. Cerium (IV) oxide was dissolved by heating for about 6 min; for cerium(IV) titanate and cerium(IV) zirconate it was about 10 min. Finally, the concentration of the cerium in the resulting solution was determined by absorption spectrophotometry or a redox titrimetric method. This method was successfully applied to various cerium compounds and ore. The cerium, titanium and zirconium in the samples were determined.View full abstractDownload PDF (793K) -
Kazuyuki NARA, Takashi SAITO1998 Volume 47 Issue 8 Pages 497-502
Published: August 05, 1998
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe determination of copper ion by flow injection analysis using a polyvinyl chloride (PVC) membrane containing 4, 7-diphenyl-2, 9-dimethyl-1, 10-phenanthroline (bathocuproine) as a detection port has been developed. The PVC membrane containing bathocuproine and ο-nitrophenyloctylether was synthesized and set in a flow-through cell; the flow-through cell was then attached in the cell holder of a spectrophotometer. A carrier solution consisting of 5×10-2 mol dm-3 of hydroxyl ammonium sulfate, 5×10-2 mol dm-3 of sodium chloride and sodium hydroxide was prepared, and pumped at 0.5 ml min-1. The sample volume was 100μl The injected copper ion formed a complex with bathocuproine on the PVC membrane surface in the flow-through cell; the absorbance of the colored membrane was then measured by the spectrophotometer at 481.5 nm. The determinable concentration of copper ion on the proposed method was over the range of 5×10-61×10-4 mol dm-3. The reproducibility of the determined values of copper ion was 3.8% with a relative standard deviation on repeatable experiments of seven times for a 5×10-5 mol dm-3 copper ions sample. Coexisting metal ions had no effect on the determined value of copper ions when their concentrations were equal to or less than the copper-ion concentration. A linear correlation between the determined values by the proposed method and AAS was obtained at a concentration range of 1×10-51×10-4 mol dm-3.View full abstractDownload PDF (806K) -
Nobuaki OGAWA, Ryoei KIKUCHI, Hiroshi GOTO, Masahiro KAJIKAWA, Toru OZ ...1998 Volume 47 Issue 8 Pages 503-511
Published: August 05, 1998
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe validity of the classification of sea-salt and non-sea-salt origins of pollutants in precipitation was evaluated using a constrained oblique rotational factor analysis. The precipitations used for this analysis were collected from April, 1993 to March, 1995 in Akita and from January to March of 1994 and 1995 in Yuzawa on a day-after-day basis. The chemical compositions in these precipitations were analyzed and their four sub-data-sets (a two-year data-set of Akita, a data-set of winter season in Akita, a data-set of seasons except for winter in Akita and a data-set of winter season in Yuzawa) were analyzed using the factor analysis. Three or four pollutant sources were quantitatively extracted for each data-set. The factor analysis has extracted a factor ascribed to the sea-salt (ss) component without using any information concerning its composition. However, a part of the sodium and chloride ion is also involved in another acidic factor, which contains sulfuric acid. This means that part of sea-salt particles suffered a chemical reaction while coming to the precipitation place from the Sea of Japan.View full abstractDownload PDF (1344K) -
Mitsuko OSHIMA, Takashi OHSAKI, Shoji MOTOMIZU1998 Volume 47 Issue 8 Pages 513-517
Published: August 05, 1998
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSUltra-trace amounts of lead were determined by graphite-furnace AAS (GF-AAS) after miniature-membrane filter (MF) concentration/dissolution. Lead was concentrated as a pyrrolidinedithiocarbamate (APDC) chelate on a miniature MF, which was 5mm in diameter, 2mm in effective filtering diameter and 0.2 μm in pore size. After collection of the lead chelate on MF, the MF was cut so as to be 3mm in diameter using a punch. This tiny MF was dissolved in 100 μl of a dissolution solvent (methyl cellosolve), which resulted in a high concentration efficiency. When 10 ml of a sample was used, the concentration ratio was 100. The addition of 5 × 10-5 M Zephiramine to the sample solution before chelation was effective for collecting lead; the recovery was almost 100%. The filtering time was 15 min for a 10 ml sample solution. The detection limit was 10 ppt when a 10 ml of sample solution was concentrated in 200 μl of methyl cellosolve. Measurements by GF-AAS were carried out using 40 μl of a methyl cellosolve solution. The relative standard deviation for 40 ppt of lead was 4.51% (n= 4). This method was applied to both river- and tap-water samples.View full abstractDownload PDF (852K) -
Zhidong CHEN, Takahiro KIYONAGA, Tsutomu NAGAOKA1998 Volume 47 Issue 8 Pages 519-521
Published: August 05, 1998
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe authors have prepared colloidal dispersions of polypyrrole-poly(vinylalcohol) composites doping carbobenzoxy-L-aspartic acid, using the oxidative polymerization technique. The colloid was used to resolve the enantiomers of glutamic acid (glu) and valine (val). When 15 mg dm-3 colloid was a-dded to a solution containing 1.0×10-4 mol dm-3 D-glu or L-glu and 2.0×10-4 mol dm-3 cupric ion, about 50% and 10% of D-and L-glu were extracted into the colloid, respectively.View full abstractDownload PDF (406K) -
Toshihide IHARA, Akiko Takatsu, Akira NOMURA1998 Volume 47 Issue 8 Pages 523-527
Published: August 05, 1998
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe Comité Consultatif pour la Quantité de Matière (CCQM) was established by the Comité International des Poids et Mesures (CIPM) in response to the issue of international comparability and traceability of chemical measurements. At its second meeting, in 1996, the CCQM working group on metrology in chemistry decided upon international comparisons for organic compounds using isotope dilution mass spectrometry (IDMS). The first CCQM inter-comparison concerning the determination of a solution of (p, p'-dichlorodiphenyl) dichloroethylene using IDMS was carried out by eight national laboratories, including our institute. Two-level (low and high) sample solutions were provided by the pilot laboratory. Our results for high-level samples showed good agreement within 1% of the reference values. Further, we had attempted an IDMS measurement using three different types of mass spectrometers : a magnetic sector, a quadrupole and an ion trap for comparing the sensitivity or reproducibility among these instruments.View full abstractDownload PDF (687K) -
Takashi YARITA, Shinji YOSHIYAGAWA1998 Volume 47 Issue 8 Pages 529-532
Published: August 05, 1998
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDownload PDF (787K)
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