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Volume 46, Issue 1
Displaying 1-13 of 13 articles from this issue
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Shukuro IGARASHI1997 Volume 46 Issue 1 Pages 1-23
Published: January 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSWater-soluble porphyrins have been extensitively studied in analytical chemistry. In order to evaluate the analytical function of these reagents, the following items, are reviewed and discussed: acid-base reactions, complex formation and spectral properties (Soret absorption band, fluorescence and phosphorescence of porphyrins). Based on these fundamental facts, various spectrophotometric methods for ppb-level trace metal ions are summarized in this article. Recently, determinations below the ppb levels of metal ions have been performed by the following methods: chemical amplification, a new pre-concentration method using fluoro-surfactant and laser analysis. Moreover, new determination methods for anion species and polyelectrolytes are described. Finally, the possibility of water-soluble porphyrins is discussed based on novel molecular designs.View full abstractDownload PDF (4827K) -
Hisao SATO, Megumi BAN, Michihisa KYOTO, Naohei NOGUCHI, Seiichiro HIG ...1997 Volume 46 Issue 1 Pages 25-30
Published: January 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSIn the present investigation we examined the curing reaction of epoxy resin using acid anhydride as a curing agent by near-infrared laser-excited FT-Raman spectrometry. The sample system was as follows. Diglycidyl-ether-bisphenol A (DGEBA) was used as the main agent, methyl nadic anhydride (MNA) as the curing agent, and 2-ethyl-4-methyl-imidazole (EMI) as the curing catalyst. Though this sample system is widely used in practice, quantitative or semi-quantitative examinations of the curing reaction have not yet been sufficiently developed. This situation is assumed to result from the fact that in infrared spectrometry the characteristic bands of the main agent severely overlap with those of the curing agent. On the other hand, in the usual Raman spectrometry using laser light in the visible region, a very strong fluorescent background is generated from this sample system illuminated by laser beam, and the spectra are hidden in this background. It was shown that when FT-Raman spectrometry is performed with a near-infrared laser as an excitation source very clear spectra consisting of sharp bands can be obtained, and the characteristic signals of each of the chemical species involved in the curing reaction in question can be recognized. On the basis of these characteristic Raman signals, the effect of the quantities of the curing catalyst on the curing phenomena was examined. It was proven that when the quantity of EMI is in the concentration range from 0.2 wt % to 2 wt %, EMI promotes a polymerization reaction between the main agent DGEBA and the curing agent MNA, which is the situation that we had expected to realize. On the other hand, when the concentrations of EMI are larger than 2 wt %, it is clear that the reaction scheme changes, and that the reaction between DGEBA and EMI takes priority over the desired curing reaction. It was concluded that the thus-obtained information is very important for the optimum curing characteristics of epoxy resin.View full abstractDownload PDF (1298K) -
Hiroaki MATSUURA, Norio MATSUURA, Norio MINAGAWA, Tetsuji HIROTA1997 Volume 46 Issue 1 Pages 31-36
Published: January 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA sensitive HPLC method with postcolumn-labeling using 2, 4-dinitropheriylhydrazine (DNPH) was developed for the determination of aliphatic aldehydes in milk, milk products, edible fat and oil. An ethanolic sample solution was prepared by mixing 10g of a food with 50 ml of ethanol. A reaction mixture was prepared by mixing 90 ml of ethanol, 2 ml of hydrochloric acid, 50 mg of DNPH and 8 ml of water. One milliliter of the sample solution was added to 1 ml of the reaction mixture. The mixture was allowed to stand at 45°C for 30 min to form aliphatic aldehydes-DNPH derivatives. Twenty microliters of the reactant were injected into an HPLC system and separated in a reversed-phase column with an aqueous solution of acetonitrile (water : acetonitrile=80:25). Aliphatic aldehydes-DNPH were completely separated in 25 min by HPLC. The detection limits, monitored at 365 nm, were about 0.040.2μg for each of the aliphatic aldehydes in 1 g of sample. The reproducibility of the HPLC measurements was 0.54.9% (RSD). This method was successfully applied to the determination of aliphatic aldehydes in milk, milk products, edible fat and oil.View full abstractDownload PDF (1175K) -
Atsushi MURASE, Takuya MITSUOKA, Motoyasu SUGIURA, Toshimi ARAGA1997 Volume 46 Issue 1 Pages 37-43
Published: January 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSIn order to determine the distribution of a small amount of carboxyl groups formed by the oxidation of polymers with micron-level lateral resolution using an analytic method, referred to as "derivatization-electron probe X-ray microanalysis (EPMA)", the suitable condition of the derivatization reaction with carboxyl groups in polymers was investigated. It was found that carboxyl groups in polymer were derivatized selectively using gas-phase esterification with 2, 2, 2-tribromoethanol (TBE). Pyridine was used as a catalyst, and dicyclohexylcarbodiimide (DCC) was used as a dehydration agent. The most suitable amounts of TBE, pyridine, and DCC in a 50 ml reaction vessel were 70 mg, 70 μl, and 50 mg, respectively. After setting a sample in the vessel without directly contacting the reagents, by heating the reagents and the sample at 110°C for 2 hours, the highest reaction yield and selectivity were obtained. By derivatization-EPMA using this derivatization condition, an analysis of the distributions of a small amount of carboxyl groups in polymers with 3 μm lateral resolution has become feasible. For example, in the case of degraded polyethylene (PE), 0.6 units of carboxyl groups per 10, 000 ethylene units can be detected. The actual applications to the depth analysis of degraded PE and Nylon-6 have proved that this method is useful for the studies on polymer degradation.View full abstractDownload PDF (1397K) -
Toshio NAKAMURA, Hiroshi NISHIKAWA1997 Volume 46 Issue 1 Pages 45-49
Published: January 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSStudies concerning the cyclic voltammetric (CV) behavior of biofunctional materials have been carried out. Three kinds of indicator electrodes were prepared by coating platinum disk electrodes with a polyacrylamide (PAA) membrane containing functional materials. Cells were then constructed with each electrode and an acetonitrile (AN) solution. The redox peak currents could be observed using the cell, in which the PAA membrane contained methylviologen. The different PAA electrodes containing a heme protein (cytochrome c, hemoglobin, or catalase) or a kind of iron ion containing antibiotics (bleomycin) showed different CV behaviors concerning the redox of oxygen. The difference in the voltammograms coinsided with a difference in the charge of the iron. The NADH and PQQ-containing PAA electrodes gave reduction currents proportional to the concentration of cyclohexanol in AN. The effects on the values of the current density of peaks due to the scan rate were also investigated in each case of the three different electrodes.View full abstractDownload PDF (878K) -
Toshiaki NOMURA, Akiko SATO1997 Volume 46 Issue 1 Pages 51-54
Published: January 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSNeutral precipitates were adsorbed on the quartz plate of an electrode-separated piezoelectric quartz crystal (electrode-separated PQC), causing a frequency change. A trace amount of iron(II) in aqueous solution reacted with 4, 7-diphenyl-1, 10-phenanthorolinedisulfonate to form an anionic complex at pH 2.55.6. The adsorption behavior of the associated ion pair formed with the complex and benzyldimethyltetra-decylammonium ion adsorbed on the quartz plate of an electrode-separated PQC and shifted the frequency. The frequency change of the electrode-separated PQC resulting from the adsorption of the precipitate depended on the pH, flow rate, and concentration of the complexing reagent and the counter ion. A linear calibration curve was obtained over the range 50500 nM Fe(II).View full abstractDownload PDF (687K) -
Atsushi TAKAHASHI, Hitoshi YAMAGUCHI, Shukuro IGARASHI1997 Volume 46 Issue 1 Pages 55-58
Published: January 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA homogeneous liquid-liquid extraction method of high-valence metal ions using desferrioxamine B (DFB) was studied. In a strongly acidic aqueous solution, DFB reacts and forms a 1:1 complex with Ti(IV), Zr(IV), V(V), Nb(V), Ta(V), Mo(VI) and W(VI) at room temperature. These metal-chelates were concentrated by a homogeneous liquid-liquid extraction method using perfluorooctanoic acid (HPFOA). Under the experimental conditions {[HPFOA]T=6.0×10-3 mol dm-3, [HCl]T=0.72 mol dm-3; [acetone]T=2.0 vol %} the volume of the sedimented phase was about 0.1 cm3 (500-fold concentration) and the extraction percentage of Ti(IV)-, Zr(IV)-, V(V)-, Nb(V)- and Ta(V)-chelates in the extraction procedure were 8398%. The concentration of metal ions in the sedimented phase was determined by X-ray fluorescence spectroscopy. The calibration curves of Ti(IV), Zr(IV), V(V), Nb(V) and Ta(V) were linear over the concentration range of the metal ions up to 2.0×10-6 mol dm-3. The relative standard deviation was below approximately 6% (5 determinations). The detection limits (S/N=3) were at 10-8 mol dm-3 levels, respectively. This method was applied to the simultaneous determination of Ti(IV), Zr(IV) and V(V) in a synthetic sample with satisfactory results.View full abstractDownload PDF (766K) -
Toshihisa OHYAMA, Kensuke ARAI, Tamaki NAKAGAWA, Chiyo MATSUBARA, Kiyo ...1997 Volume 46 Issue 1 Pages 59-62
Published: January 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe present study was conducted to assess poly (vinyl methyl ether) (PVME) for collecting chemical substances in water in an attempt to provide a preconcentration and separation procedure for constituent species in a urine analysis. Although PVME, a thermally reversible polymer, is soluble in water below 31°C, it coagulates upon heating at above 31°C, and becomes insoluble. With a phase separation of PVME from an aqueous solution, certain substances in solution were incorporated into the coagulated polymer. An assessment was made for some familiar substances as urine components. Collection ratios obtained were appreciable (1299.6%) for fatty acids, phospholipids and steroids. Contrary to this, inorganic cations and anions, glucose, creatinine and urea were scarcely collected in PVME PVME was thus found very useful for the preconcentration of hydrophobic substances while removing hydrophilic substances in urine sample.View full abstractDownload PDF (799K) -
Tsuneaki MAEDA, Yasuhide HISAMOTO, Masanori ANDO1997 Volume 46 Issue 1 Pages 63-68
Published: January 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSFor the water standard mixture (volatile organic compounds), 23 kinds (VOC-23) have been widely used for the analysis of drinking-water quality, the regulated water quality standard and the regulated waste-water quality standard. Still, there is no uniform quality-control standard or regulation concerning the quality of their commercially available standard mixture, also, quality is controlled and assured by each manufacturer. A relative comparison has been conducted for the standard mixtures concerning the difference among manufacturers. Also, the analytical method used to evaluate the quality control is discussed in this paper. The sample injection methods using in this paper were the split injection, on-column injection and purge & trap method, utilizing the capillary column GC/FID. A comparison of the relative sensitivity using the standard material (1, 1, 2-trichloroethane kept in the reagent) made it clear that the difference among the reagents remained within the latitude of the measurement tolerance. Further, although a comparison of the sensitivity between a 1, 1, 1-trichloroethane which elute the earlier stage on a chromatogram and its isomer, 1, 1, 2-trichloroethane, which elute at a later stage, the measuring result was identified depending on whether or not it had been done correctly. The same evaluation method can be applied to evaluate the total quality of the analysis, including any error caused by the dilution procedure. Although there was no recognition of a difference between the reagents made by various manufacturers, a further study and evaluation of the absolute values must be pursued from now on.View full abstractDownload PDF (1071K) -
Hisashi AKUZAWA, Hideo AKAIWA1997 Volume 46 Issue 1 Pages 69-74
Published: January 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSHigh-performance liquid chromatography (HPLC) was applied for a simple and rapid determination of DL-homoalanine-4-yl (methyl) phosphinic acid (commercial name: Glufosinate, GLF). GLF was derivatized with 9-fluorenylmethyl chloroformate (FMOC-Cl) and injected into an octadecylsilyl (ODS) column (4.6 mm i.d., 150 mm L) equipped with a fluorescence detector (Ex 265 nm, Em 315 nm). The derivatization was completed within 10 min at 40°C. The calibration curve was linear between 0.2 μ·g cm-3 and 20.0 μ·g cm-3 of GLF-FMOC, the detection limit being 1 ng·cm-3. In the case of GLF determinations in such biological samples as blood and urine, sodium borate buffer (pH 8.5) and acetone were added in order to remove proteins. By injecting the supernatant into HPLC, GLF was rapidly determined with high sensitivity.View full abstractDownload PDF (1073K) -
Koji YAMAGAKI, Michinao YOSHII, Minetaka KONDO, Yutaka SAKAI1997 Volume 46 Issue 1 Pages 75-79
Published: January 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThis report describes modified graphite-furnace AAS (GFAAS) method for the determination of aluminium in sludges collected from a sedimentation pond in a water-treatment plant. Interfering substances in the acid extract from sludge are removed by extraction with solvents, such as 4-methyl-2-pentanone (MIBK). Aluminium is extracted by 8-quinolinol-chloroform; nickel nitrate is added to the sample solution as a matrix modifier in order to increase its recovery. The analytical value of aluminium in standard pond sediment agreed with its certified value (106±5 mg, Al/g) with decreasing the relative standard deviation (R.S.D=1.51%). The value of aluminium in water-treatement sludge was 39.3 mg Al/g and the RSD was 1.10%.View full abstractDownload PDF (840K) -
V. Dependence of molecular weight averages on detectors and mobile phasesS. MORI, S. TAKAYAMA, Y. GOTO, M. NAGATA, A. KINUGAWA, T. HOUSAKI, M. ...1997 Volume 46 Issue 1 Pages 81-86
Published: January 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe effects of the differences in detectors and mobile phases on the calculated molecular-weight averages are discussed based on the data obtained from 1st and 2nd round-robin tests. Although the weight-average molecular weights (Mw) of polystyrene (PS) samples remained unchanged with the detectors, the number-average molecular weights (Mn) obtained with an ultraviolet absorption detector (UV) were 7488% of those with a differential refractometer (RI). The fractions at a lower molecular weight range of the differential molecular-weight distributions, calculated using UV chromatograms, were higher than those based on RI chromatograms, which caused the Mn, obtained by a UV detector to have smaller values than those by an RI detector. Peak broadening due to the cell structure or the difference in the molecular-weight dependence of the response coefficients of UV and RI detectors were negative as the main reason. The most probable assumption was that the end-structure of the PS samples affected the increase in the UV absorption. When a comparison of the Mn, values between laboratories is required, the type of detector for size-exclusion chromatography must be the same. The values of Mn and Mw for poly (methyl methacrylate), obtained with chloroform mobile phase, were 525% higher than those with the tetrahydrofuran mobile phase. PS standards were used for the calibration; in this case, the change in the values of Mnand Mw for other types of polymers than PS using different mobile phases had to be taken into account.View full abstractDownload PDF (1092K) -
Jun Yan CAO1997 Volume 46 Issue 1 Pages 87-88
Published: January 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDownload PDF (342K)
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