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Volume 53, Issue 11
Displaying 1-19 of 19 articles from this issue
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Review
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Kiyoshi SAWADA, Yoichi KIKUCHI2004 Volume 53 Issue 11 Pages 1239-1255
Published: 2004
Released on J-STAGE: March 28, 2005
JOURNAL FREE ACCESSThe complex formation of non-cyclic linear polyoxyethylenes and their alkyl derivatives (POE compounds) and application to analytical chemistry are reviewed. The POE compounds form the complexes with alkali and alkaline earth metal ions in the same manner as the cyclic one (crown ether). Although the selectivity and stability of the complex formation are inferior to that of crown ether, POE compounds are interesting material because they have flexible structure and the compounds having a very long ethylene oxide (EO) unit are available. The structures of the crystalline complexes have been determined as the metal ion is surrounded by EO moieties and similar structures are estimated for the complexes in solution. Generally they form 1 : 1 complexes with a metal ion. In case of long chain POE compounds, however, polynuclear complexes are formed. POE compounds are widely used as non-ionic surfactants (NIS). The complexation of POE compounds has been applied to various separation and determination methods, such as solvent extraction, trace analysis of NIS and metal ions and so on. Peculiar properties of POE compounds as NIS have been also utilized for various analytical methods.
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Junichi TAKAHASHI, Noriyuki YAMADA2004 Volume 53 Issue 11 Pages 1257-1277
Published: 2004
Released on J-STAGE: March 28, 2005
JOURNAL FREE ACCESSAmong the various methods applied to reduce spectral interference in ICP-MS, collision technology, which utilizes gaseous molecules to eliminate interfering ions, has been demonstrated to be one of the most effective techniques. Helium, hydrogen, ammonia, methane and oxygen are mainly used as collision gases. Although by-product ions are sometimes found as a result of the ion-molecule reactions involved in this technology, these undesirable ions are successfully suppressed by energy discrimination, or a band-pass tuning technique. The principle of the technology, the optimization method of the instrumental parameters and the major applications to various samples are described along with comments on the possibilities and limitations of the technology.
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Account
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Masashi2004 Volume 53 Issue 11 Pages 1279-1293
Published: 2004
Released on J-STAGE: March 28, 2005
JOURNAL FREE ACCESSIn aqueous solution, alkali metal and alkaline earth metal salts are regarded to be "indifferent salts" or supporting electrolytes, which should change the activity coefficients of ionic species. Although higher ion aggregates from 1 : 1 type electrolytes in low-permittivity media (εr<10) are widely accepted, only few chemists have recognized higher ion aggregation in higher permittivity media. However, we have clarified that the chemical interaction, such as coordination, can operate between anions and cations in non-aqueous solvents (20<εr<65) of low solvation ability. Acids (HA) and their conjugate base anions (A−) may react with each other to form homoconjugated species, such as A−(HA)2, in acetonitrile or benzonitrile, protophobic aprotic solvents with low hydrogen-bonding donor and acceptor abilities. After observing the direct reaction of some anions (e.g. Cl−) and cations (e.g. Li+) toward a certain species, we comprehensively interpreted the salt effects in chemical equilibria, based on distinct chemical interactions and not merely a vague term, "medium effect". A reaction manner similar to that in non-aqueous solution can take place, even in some "aqueous" solution, if the water structure of the aqueous solution is completely destroyed, because the properties of bulk water should arise from a huge network of water molecules by hydrogen bonding; otherwise, the properties of water must be reduced to just those of isolated H2O molecules, termed, "dihydrogen ether". The chemical interaction between ions has been proved in "aqueous" solution of low water-structuredness with the addition of concentrated salts and non-aqueous solvents; a minor increase of the intermediate species that would never be observed in the chemical equilibrium sense could be multiplied into a measurable change in the chemical kinetics.
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Research Paper
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Azusa OGA, Kazuaki YAMAOKA, Kazuyuki ITANO, Yuko HASEGAWA2004 Volume 53 Issue 11 Pages 1199-1206
Published: 2004
Released on J-STAGE: March 28, 2005
JOURNAL FREE ACCESSThe extraction constants represented by Kex=[LnA3]o[H+]3[Ln3 +]−3[HA]o−3 were determined across the lanthanoid series, in the extraction of lanthanoids(III) with acetylacetone (Haa), benzoylacetone (Hbza), benzoyltrifluoroacetone (Hbfa), and hexafluoroacetylacetone (Hhfa) from 0.1 mol dm−3 NaClO4 into CHCl3 at 25°C. The extraction constants increased along with increasing the lanthanoid atomic number. However, the degree of the variation of the extraction between adjacent lanthanoids decreased in the sequence of Haa—∼Hbza>Hbfa>Hhfa, i.e., the extraction constants with β -diketones, possessing a smaller number of F atoms, showed the larger variation for the lanthanoid. In addition, when the stability constants of the aqueous chelates of lanthanoids(III) with Hhfa and Haa were determined by potentiometric titration and the solvent-extraction technique, the constants of the aa chelates increased along with the atomic number, while those of the hfa chelates did not change over the series. Accordingly, it was concluded that the increase of Kex with Haa for the lanthanoid series depends on the change in the stability constants as well as the distribution constants of the extracted species, while the similar values of Kex with Hhfa across the series was contributed by similar stability constants.
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Kenji KODAMA, Kazuaki WAGATSUMA2004 Volume 53 Issue 11 Pages 1207-1213
Published: 2004
Released on J-STAGE: March 28, 2005
JOURNAL FREE ACCESSThe introduction of a d.c. bias current to an r.f. glow-discharge plasma led to an intensity increase of particular emission lines. It was considered that the excitation mechanism was investigated based on Boltzmann plots of chromium emission lines with and without the introduction of a bias current. In the case of Cr I lines, the Boltzmann plot follows a straight lines without bias-current introduction, whereas it bends upwards when a bias current is introduced. This effect could be explained from the fact that the excited levels having energies of 4.2 eV and 5.8 eV were more populated compared to the excited levels of 3.3 eV through collisions with introduced electrons. On the other hand, the Boltzmann plot of Cr II lines bends downwards with no bias currents, which is caused by the selective excitation of Cr ion species having excitation energies of 8 eV through charge-transfer collisions between Cr atoms and Ar ions. When bias currents were introduced, the charge transfer collisions could be less effective, leading to a straight-line relationship of the Boltzmann plot of the Cr II lines. These results effects suggest that introducing a bias current is effective to enhance the intensities of not only the Ni or Cr atomic emission lines, but also the other atomic-emission lines.
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Chikako OKUMURA, Hiroshi HASEGAWA, Hidenobu MIZUMOTO, Teruya MAKI, Kaz ...2004 Volume 53 Issue 11 Pages 1215-1221
Published: 2004
Released on J-STAGE: March 28, 2005
JOURNAL FREE ACCESSWe determined iron speciation in laboratory cultures containing a radioactive tracer, 55Fe, and chelating ligands using a size-fractionation method. For the size-fractionation of iron, filters with 0.025, 0.20 and 3.0 μm pore size were used. In the media with chelating ligands, major species of iron were colloidal and truly dissolved fractions. When cells of phytoplankton were added, the colloidal fractions decreased, while the large particle fractions (>3.0 μm) increased in the cultures. The iron uptake of phytoplankton, especially extracellular iron, was correlated with the colloidal iron fractions, of which the concentrations depended on the chelating ligands in the media. It is likely that phytoplankton absorbed the colloidal iron fractions onto the cell surface and that utilized the fractions as an iron source in the cultivated media.
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Miho SEGAWA, Shouko KOBAYASHI, Haruo TUJI, Kenji CHAYAMA2004 Volume 53 Issue 11 Pages 1223-1228
Published: 2004
Released on J-STAGE: March 28, 2005
JOURNAL FREE ACCESSA polymer-mediated extraction system using 1,9-diphenyl-2,5,8-trithianonane (9-2Ph-SSS) as extractant and Poly-N-isopropylacrylamide (PNIPAAm) as an extraction medium for noble metal ions was examined. The system was compared with the liquid-liquid extraction system using the same ligand and 1,2-dichloroethane as an organic solvent. The results showed that soft metal ions (class b metal ions) were extracted well as the metal trithioether complex by both systems. On the other hand, class ab metal ions such as cobalt(II), nickel(II), manganese(II), copper(II) and zinc(II) ions were incorporated into solid phase of the polymer as hydroxide at pH higher than 6. A masking agent EDTA was added to polymer mediated system to prevent the formation of hydroxide, resulting in a highly selective extraction system for noble metal ions, such as silver(I), copper(I) and palladium(II) as well as the liquid-liquid extraction system.
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Hiroyuki NAKAZAWA, Yukiko KANZAKI, Nobuyuki TAKAHASHI, Hisao OKA2004 Volume 53 Issue 11 Pages 1295-1301
Published: 2004
Released on J-STAGE: March 28, 2005
JOURNAL FREE ACCESSA new strategy, based on immunoaffinity extraction coupled with flow-injection-electrospray tandem mass spectrometry (IAE-FI-MS/MS), has been developed for a screening method of phenoxy acid herbicides. This method uses polyclonal antibody produced against a protein for conjugating the phenoxy acid herbicides. Silvex, Mecoprop, Dichlorprop and 2,4-D were monitored in the multiple reaction monitoring (MRM) mode with the selection of m/z 267/195 for Silvex, m/z 213/141 for Mecoprop, m/z 233/161 for Dichlorprop and m/z 219/161 for 2,4-D, respectively. The use of highly selective IAE in sample preparation prior to FI-MS/MS analysis allowed the removal of interfering compounds present in the sample extracts, that would cause severe ionization suppression of the phenoxy acid herbicides during the electrospray process. In addition, the analysis time, including sample preparation and determination for 96 samples, required only 100 minutes for the screening for residual Silvex, Mecoprop, Dichlorprop and 2,4-D by using a 96-well microtiter plate.
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Technical Paper
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Yasutada SUZUKI, Takayuki ITO, Tsugio FUKASAWA, Susumu KAWAKUBO, Masaa ...2004 Volume 53 Issue 11 Pages 1303-1308
Published: 2004
Released on J-STAGE: March 28, 2005
JOURNAL FREE ACCESSTwo electroanalytical instruments, such as a power supply for electrogravimetry and a constant-current coulometric analyzer, were developed for quantitative semimicro analysis experiments in an undergraduate course. The power supply for electrogravimetry contained a variable-voltage power supply and an electronic load; they controlled the potential and current of electrolysis, respectively. It also contained an embedded controller and a liquid-crystal display (LCD), and could display the potential and current. It was applied to the determination of copper in copper(II) sulfate pentahydrate. The obtained results were 98∼103% of theoretical values. On the other hand, the coulometric analyzer contained a constant-current power supply for electrogeneration of the titrant, a constant-voltage power supply for the indicator circuit, an amplifier and an analog-to-digital converter for the indicator current measurement, and an embedded controller and an LCD to display the indicator current and the elapsed time of electrolysis. It was applied to the determination of thiosulfate with electrogenerated iodine. The obtained results were in good agreement with a conventional instrument. Both instruments were not only applicable to quantitative semimicro analysis experiments, but also their dimensions and power consumption were markedly reduced.
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Toshiyuki ENAMI, Norikazu NAGAE2004 Volume 53 Issue 11 Pages 1309-1313
Published: 2004
Released on J-STAGE: March 28, 2005
JOURNAL FREE ACCESSThe retention behavior of the reversed phase was evaluated under 100% aqueous conditions. It is commonly said that reversed phases, such as ODS (C18) and C8, show a decrease of the retention time under 100% aqueous conditions. It was previously reported that the mechanism of the decrease in retention was found to be that the 100% aqueous mobile phase was expelled from the pore of the packing materials, so that the stationary phase in contact with the mobile phase decreased. In this study, the wettability between the C18 stationary phase and water as a mobile phase was analyzed. It was concluded that the retention behavior could explained by capillarity, and reversed-phase separation could be carried out under 100% aqueous conditions, even if a mobile phase can not wet the stationary phase.
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Note
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Koich AKIYAMA, Tadashi NAKANISHI, Ryo OHNISHI, Tasuku AKAGI2004 Volume 53 Issue 11 Pages 1229-1232
Published: 2004
Released on J-STAGE: March 28, 2005
JOURNAL FREE ACCESSDissolution methods for the determination of silicon in plant samples with inductively coupled plasma atomic emission spectrometry (ICP-AES) were examined. Plant samples (0.1 g) ashed by an electric furnace at 700°C were dissolved by three methods: an acid dissolution method, where the ashes were dissolved with a hydrochloric acid solution; an alkaline dissolution method, where the ashes were dissolved with a sodium carbonate solution; and an alkaline fusion method, where the ashes were fused with sodium carbonate salt. The effect of evaporation after dissolution was also examined. It was found that evaporation exerted a critical effect on the analytical results of silicon, i.e., complete evaporation reduced the results to about half that obtained with incomplete evaporation. Two tea leaf samples (commercial and sampled) with a low silicon concentration could be dissolved by all three methods when the resultant solution was followed by incomplete evaporation. The reproducibility of the silicon concentration with the alkaline dissolution method and acid dissolution method was about 3%, and the recovery of silicon after both methods was more than 95%. In the case of Magnolia leaves with a high silicon concentration, the alkaline dissolution method gave a greater concentration of silicon with better precision (5%) than the alkaline fusion method.
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Mitsuyoshi HOSHINO, Kunio NAGASHIMA, Minori KAMAYA, Nobuo NAKANO2004 Volume 53 Issue 11 Pages 1315-1319
Published: 2004
Released on J-STAGE: March 28, 2005
JOURNAL FREE ACCESSA sample solution was pumped at a flow rate of 3 ml min−1 to the mixing joint, where a sulfuric acid(0.05 M) was mixed at a rate of 2 ml min−1. A mixture containing hydrogen cyanide was fed into a gas-liquid separation tube(pore size, 1 μm; microporous Teflon tube of 2 mm i.d., 3 mm o.d., 900 mm length). Hydrogen cyanide evolved from the gas-liquid separation tube was purged by purified air (400 ml min−1) onto HCN monitoring tape. The efficiency of the gas-liquid separator used was about 3%. The monitoring tape used was porous cellulose tape containing silica gel, N,N-diethyl-p-phenylenediamine, Cu(CH3COO)2 and glycerin. When the tape was exposed to HCN gas, the tape became colored homogeneously. The degree of color intensity was proportional to the concentration of CN− in the sample solution. The relative standard deviation of the response to 0.1 mgCN− dm−3 was 1.2%. The calibration curve showed a rectilinear behavior in the range of 0.01∼0.3 mgCN dm−3. The method has detection limits of 0.01 mgCN dm−3 for free cyanide ion with a sampling time of 5 min. This method could detect free cyanide ions, and indirectly Cu(II) and Cd(II) cyano complexes when the metal concentrations were below 10 mg dm−3.
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Zhidong CHEN, Tsutomu NAGAOKA2004 Volume 53 Issue 11 Pages 1321-1324
Published: 2004
Released on J-STAGE: March 28, 2005
JOURNAL FREE ACCESSA self-assembled monolayer consisting of 3,3'-thiodipropionic acid and n-decyl mercaptan formed on a gold electrode was studied for a sensitive and selective determination of dopamine. The experimental results show that the monolayer exhibits both excellent sensitivity and stability, even in the presence of ascorbic acid and protein. A detection limit of 5.0×10−6 M for dopamine was obtained in flow injection analysis by the optimizing experimental conditions, such as the solution pH, flow velocity of the carrier solution and the electrode potential. The current response of the modified electrode showed excellent stability in the presence of 0.2% albumin. Even with ascorbic acid in 10-fold excess, dopamine could be detected within an error of about 3%.
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Yoichi TAKEDA, Koji ISHIDA2004 Volume 53 Issue 11 Pages 1325-1328
Published: 2004
Released on J-STAGE: March 28, 2005
JOURNAL FREE ACCESSThe adsorption behavior of all the rare earths, except for promethium, was surveyed on carboxymethyl cellulose thin layers in sodium nitrate solutions as a function of the concentration of salt. At lower salt concentrations, the Rf values of the lanthanoids showed an S-shaped variation with their atomic number, and yttrium lay near to lanthanum, relatively analogous to the adsorption behavior in chloride solutions. At higher salt concentrations, the behavior of the metals was considerably different from that in the chloride solutions, and the Rf values of the lanthanoids decreased with an increase of their atomic number. The Rf value of yttrium gradually approached that of europium with increasing salt concentration in nitrate media. Two-dimensional development appeared first with a 0.5 M sodium chloride solution and second with a 5 M sodium nitrate solution, allowing yttrium to be separated from all of the rare earths.
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Hiroaki FUKUI, Osamu FUJINO, Shigeo UMETANI2004 Volume 53 Issue 11 Pages 1329-1334
Published: 2004
Released on J-STAGE: March 28, 2005
JOURNAL FREE ACCESSThe magnesium in hard tissues (shell and pearl) of shellfish inhabiting freshwater and sea water was determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES) after solvent extraction separation. We examined whether ICP-AES signals for magnesium were highly suppressed, or increased by large amounts of calcium ions. Two interferences, spectral and physics, were generated by the macro-component calcium for the emission intensity of magnesium. These interferences occurred simultaneously for magnesium. In addition, the calcium of the large excess adhered to a quartz torch, and the tip minute of the torch was damaged. From these results, it became cleare that it is necessary to separate magnesium from calcium prior to a measurement by ICP-AES. To eliminate this problem, we applied the solvent extraction method to separate magnesium from the interfering element, calcium. The chelating agent was easy to form the chelate with magnesium, and then a reagent that could extract the chelate from the acid solution was chosen. 1-phenyl-3-methyl-4-trifluoroacetyl-5-pyrazolone (HPMTFP) having a pKa value of 2.56 was chosen as the extraction reagent. Also, we selected some organic solvents in which the carbon did not adhere to torch without extinguishing plasma on the extractant. The sample solutions of shell and pearl used in the present work were treated with hot concentrated nitric acid, hydrochloric acid and perchloric acid. Magnesium was extracted with 0.01 mol/l-HPMTFP in dibutyl ether at pH 4.5 in order to separate it from the interfering calcium. Magnesium was determined by ICP-AES, and direct injection of the dibutyl ether. The magnesium content in the shell and pearl was found to be 16.4∼2627 μg/g.
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Analytical Report
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Takanori TAKII, Kenichirou SUZUKI, Satoshi NAKANO, Miyuki YOSHIZAWA, M ...2004 Volume 53 Issue 11 Pages 1233-1237
Published: 2004
Released on J-STAGE: March 28, 2005
JOURNAL FREE ACCESSWe performed a source apportionment for particulate matter under 2.5 μm with the diameter (PM2.5) based on individual particle analyses using an electron probe microanalyzer (FE-SEM/EPMA). The analyzed particles were collected from the air environment near to a traffic route in June (before diesel vehicle emissions control regulations) and December (after regulations) 2003. From the results of the size, shape, and components of the particles, five or more sources of the particles were estimated. The rates for the contribution of diesel exhaust particle (DEP) were higher than that of the other sources. DEPs were further classified based on information concerning light elements according to the X-ray spectrum patterns. The X-ray spectrum patterns of DEPs collected before diesel vehicle emissions control regulations were different from that collected after the regulations. We could obtain this information about PM2.5 and DEPs, which could not be obtained by the conventional method. Therefore, it is concluded that the combination of individual particle analysis based on FE-SEM and EPMA is one of the most powerful techniques for obtaining detailed information about PM2.5.
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Kensaku OKAMOTO, Takashi IMAGAWA, Hiroyasu ITO, Masahiro TAKEUCHI, Shi ...2004 Volume 53 Issue 11 Pages 1335-1345
Published: 2004
Released on J-STAGE: March 28, 2005
JOURNAL FREE ACCESSThe Japan Society for Analytical Chemistry has developed two new certified reference materials (CRMs) for dioxins and coplanar PCBs. A project team was organized to prepare 2 kinds of forest soil and to certify the concentration of dioxins. An interlaboratory comparison test was performed with the participation of 15 laboratories. In a statistical, analysis, z-scores in the "robust method" were applied to estimate the degree of bias of reported data from the mean value in order to reject any data with a big bias, and was followed by the usual statistical procedure. The presented CRMs are expected to be useful for the quality assurance and quality control of dioxins analysis.
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Yo-ichi ISHIBASHI, Shozo ASADA, Hiroyuki IGAKI, Shu-ichi YAMADA, Satos ...2004 Volume 53 Issue 11 Pages 1347-1354
Published: 2004
Released on J-STAGE: March 28, 2005
JOURNAL FREE ACCESSThe Japan Society for Analytical Chemistry carried out proficiency testing on the determination of dioxins (polychlorodibenzo-p-dioxins, polychlorodibenzofurans and coplanar polychlorobiphenyls) in fly-ash of a waste incinerator. The proficiency testing of analytical laboratories is based on ISO/IEC Guide 43-1 "Proficiency testing by interlaboratory comparisons". This testing was carried out from November 2000 to March 2001, with the participation of 41 laboratories. The test results were; 0.987 ng-TEQ/g of total dioxin concentration on the average, 13% in robust standard deviation. Two labs were judged to be unsatisfactory because of their large z-score in the robust method (over 3 in absolute value).
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Hiroshi MITSUMATA, Toshio MORI, Kazuo SAIMOTO2004 Volume 53 Issue 11 Pages 1355-1358
Published: 2004
Released on J-STAGE: March 28, 2005
JOURNAL FREE ACCESSWe have established a method for assaying the quantities of silicon and copper in aluminium alloys deposited by sputtering on silicon substrates. This method involves the following procedure: 1) The alloy film is peeled away with a metal blade, while taking care not to damage the silicon substrate. 2) The peeled film is dissolved in a hot 1% aqueous solution of sodium hydroxide. 3) The solution is acidified with nitric acid, and the quantities of silicon and copper are assayed by inductively coupled plasma optical emission spectrometry(ICP-OES). We have clarified that this method can assay silicon and copper in as little as 20 mg of peeled aluminium alloy.
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