BUNSEKI KAGAKU, Abstracts

Vol. 4 8, No. 1

January, 1999


Review

Dynamic characterization of metal ions and their complexation rates (Review)

Shigenobu Funahashi**

**Laboratory of Analytical Chemistry, Faculty of Science, Nagoya University, Chikusa, Nagoya 464-8602

(Received 30 June 1998)

The reactivities of metal ions are reviewed on the basis of dynamic behaviors of the metal ions in solutions including structural and dynamic information on solvated structures and solvent-exchange rates of metal ions in various solvents. The dynamic characterization of metal ions has been performed in terms of rates of complexation reactions of metal ions. The kinetic determinations concerned are briefly reviewed and recent advance for analysis of reactive intermediates is shown.

Keywords: dynamic characterization; solvated metal ion; solvent exchange; metal complex formation; complexation mechanism; reactive intermediate; kinetic chelate effect; kinetic determination.


Accounts

Development of ancillary techniques in capillary supercritical fluid chromatography

Yukio Hirata**

**School of Materials Science, Toyohashi University of Technology, Tempaku-cho, Toyohashi-shi, Aichi 441-8580

(Received 30 June 1998, Accepted 31 July 1998)

Capillary supercritical fluid chromatography (SFC) has been recognized as being a powerful tool for the separation of thermally labile or involatile species which are not amenable to gas chromatography. It also provides a higher column efficiency than does HPLC. To fully utilize the ability and high efficiency of capillary SFC, however, further improvements in the current technology and the development of new techniques are indispensable. First, in this article, various sample-introduction methods which can inject sample volumes ranging from low to high micro litters are presented. Second, methods for controlling the UV cell pressure and temperature as well as preparing a mixed mobile phase are presented, and their ability demonstrated. Finally, an interface for two-dimensional capillary SFC and its principle are described.

Keywords: capillary supercritical fluid chromatography; sample introduction; UV detection; mixed mobile phase; two-dimensional separation.


Approach to ion separation using polydentate ligands having aromatic-ring pendant arms

Naoki Hirayama**

**Department of Chemistry, Faculty of Science, Kanazawa University, Kakuma-machi, Kanazawa-shi, Ishikawa 920-1192

(Received 18 June 1998, Accepted 6 August 1998)

The analytical use of polydentate ligands having plural "aromatic-ring pendant arms," such as 2-pyridylmethyl, 1-pyrazolylmethyl and 2-hydroxyphenylmethyl groups, for not only the separation of cations, but also that of anions, was investigated fundamentally. These ligands generally have a specific nature at many points, such as hydrophobicity, electric effects, structural rigidity and sterical selectivity, originating from the aromatic-ring pendant arms; also, upon the mutual separation of many kinds of metal cations by solvent extraction they can act as extraction reagents having specific reaction selectivity. As one example, the extraction selectivity of divalent transition metal cations using N,N'-bis(2-hydroxyphenylmethyl)-N,N'-bis(2-pyridylmethyl)-1,2-ethanediamine (H2bbpen) did not agree with the Irving-Williams series of stability; it was suggested that ion-size recognition based on the cavity size of the ligand acted in this extraction system. Upon the extraction of trivalent lanthanoids, as another example, N,N'-bis(5-nitrosalicylidene)-1,2-ethanediamine (H2Nsalen) showed high performance for their mutual separation, originating from the structural ligidity of the ligand. Furthermore, an immobilized charged complex between bis(2-pyridylmethyl)amino group (bpa-group) and a metal cation was useful as an anion-exchange group in ion chromatography, having specific anion selectivity originating from its additional ligand-exchange ability.

Keywords: polydentate ligands having aromatic-ring pendant arms; structural rigidity and steric selectivity; solvent extraction; ion chromatography; anion-exchange group having ligand-exchange ability.


Metal ion sensing and separation using chromogenic polythiazaalkane derivatives

Junichi Ishikawa**, Hidefumi Sakamoto***, Hiroko Wada and Makoto Otomo**

**Department of Applied Chemistry, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-0061
***Department of Applied Chemistry, Faculty of Systems Engineering, Wakayama University, 930, Sakaedani, Wakayama 640-8510

(Received 24 June 1998, Accepted 11 August 1998)

Acyclic and cyclic dithiaza- and tetrathiazaalkane derivatives bearing the 6-trifluoromethyl-2,4-dinitrophenylhydrazono moiety as a chromogenic group on the nitrogen atom of the alkanes were synthesized and studied as complexing chromogenic reagents for a particular metal ion. In order to evaluate the metal ion recognition properties of these compounds, the following behaviors were examined: proton dissociation, metal ion complexation, metal ion extraction, and metal ion transport through a liquid membrane containing the compound. First, all of the hydrazone derivatives exhibited a similar proton dissociation constants and a silver ion selective complexation behavior in a 1,4-dioxane-water solution. The blue shifts of the absorption spectra were caused by complexation of the hydrazone derivatives with silver ion. The complexing ability is mainly dependent on the number of sulfur atoms in the molecule. Secondly, tetrathiazaalkane hydrazone derivatives exhibited high selectivity for silver ion in the solvent extraction of some heavy metal ions. Drastic red shifts of the absorption spectra of the organic phase were observed in the extraction of silver ion with tetrathiazaalkane hydrazone derivatives. Acyclic tetrathiazaalkane hydrazone derivative extracted silver ion most efficiently. Thirdly, tetrathiazaalkane hydrazone derivatives exhibited effective uphill silver ion transport ability. Especially, a rapid and selective transport of silver ion was observed for an acyclic tetrathiazaalkane analog through liquid membranes.

Keywords: chromoionophore; polythiazaalkane; silver ion; complexation; solvent extraction; liquid membrane transport.


Multielement determination of major-to-ultratrace elements in biological samples by analytical plasma spectrometry

Eiji Fujimori**, Kazumi Inagaki and Hiroki Haraguchi***

**Waste Treatment Facility, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603
***Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603

(Received 22 June 1998, Accepted 2 September 1998)

The multielement determination of major-to-ultratrace elements in biological samples by ICP-AES (inductively coupled plasma atomic emission spectrometry) and ICP-MS (inductively coupled plasma mass spectrometry) is reported. Matrix effects, especially due to organic compounds contained at high concentrations in biological samples, were examined in detail in terms of non-spectral interference and polyatomic ion interference. It was found that the interference of 40Ar12C with 52Cr could be corrected by the CF (correction factor) method, which was estimated from the apparent ion counts of 52Cr and the emission intensity of C at 247.8 nm. The major-to-ultratrace elements in freeze-dried human urine standard reference material (NIST SRM 2670; elevated) and human hair reference material (NIES CRM No. 13) were determined using both ICP-AES and ICP-MS. Furthermore, rare earth elements (REEs) in human blood serum (human blood serum reference material NIES CRM No. 4 and personal human blood serum samples) were determined by ICP-MS after acid digestion and chelating resin preconcentration. The REE distribution pattern of human blood serum showed some similarity to that of seawater.

Keywords: ICP-MS; ICP-AES; biological samples; multielement determination; rare earth elements.


Retention behavior in ion chromatography using stationary phases modified with ionic polysaccharides

Toyohide Takeuchi**

**Department of Chemistry, Faculty of Engineering, Gifu University, 1-1 Yanagido, Gifu 501-1193

(Received 1 July 1998, Accepted 7 October 1998)

The retention behavior of analyte ions on silica-based anion exchangers modified with anionic polysaccharides, such as mucopolysaccharides and dextran sulfate, has been investigated using ion chromatography. The anion-exchange capacity of the substrate was remarkably reduced by the modification, whereas cation-exchange properties were induced. The modified stationary phases possess residual anion-exchange sites of the substrate as well as cation-exchange sites due to free anionic groups of the modifier. The pore size of the substrate and the molecular weight of the modifier strongly affected the retention behavior of the analyte ions. Since both anions and cations were retained on the modified stationary phase, the cation and the anion of the eluent affected the retention behavior of the analyte ions. Under appropriate conditions both the anions and the cations were simultaneously separated on the modified stationary phase.

Keywords: ion chromatography; anionic polysaccharides; retention behavior; separation of anions and cations.


Original Papers

Matrix effects and the relationship between the relative sensitivity factors and the ionization potential in glow discharge mass spectrometry using Kr/0.2 vol.%H2 mixture

Morimasa Saito*

*National Research Institute for Metals, Materials Physics Division, 1-2-1, Sengen, Tsukuba-shi, Ibaraki 305-0047

(Received 15 June 1998, Accepted 19 August 1998)

Glow discharge mass spectrometry (GDMS) using Kr/0.2 vol.%H2 mixture has been studied. The relative sensitivity factors (RSFs) for the analysis of 23 elements were determined based on a multiple determination of 10 reference materials representing steels, heat-resisting alloy, copper, aluminum, molybdenum and indium. The proposed method decreases the matrix effect, compared with the results obtained by Kr gas alone. In addition, when the technique combined with a liquid-nitrogen cryogenic-cooling Mega cell was used, a linear relationship was found to exist between the RSF values on the logarithmic scale and the first ionization potential of the elements. This proposed method may be determined without the use of standard refernce materials.

Keywords : glow discharge MS; Kr/0.2 vol.%H2 mixture; matrix effect; relative sensitivity factor and ionization potential.


Spectrophotometric determination of ionic surfactants on the basis of a color change of fluorescein dyes with a quaternary ammonium ion

Koichi Yamamoto and Mutsuko Kadono*

*Department of Materials Science, Yonago National College of Technology, 4448, Hikona-cho, Yonago-shi, Tottori 683-8502

(Received 29 June 1998, Accepted 24 August 1998)

A method for the spectrophotometric determination of ionic surfactants (cationic surfactants (CS+), such as quaternary ammonium salts containing a long-chain alkyl group, and anionic surfactants, such as sodium lauryl sulfate (LS-)) with Fluorescein dyes (Rose Bengal(RB), Phloxine B(PhB)), has been developed. The addition of CS+ to RB or a PhB solution buffered at pH 3 leads to an increase in the absorbance at 568 nm or 558 nm, respectively; also, when LS- is added to the solution, the absorbance at 568 nm or 558 nm decreases with increasing amounts of LS-. This decrease in absorbance is caused by an ion association of CS+ with LS-. The calibration graph based on this principle shows linearity up to 1×10-5 M of CS+ and from 2×10-6 to 1×10-5 M of LS- with RB and up to 1×10-5 M of CS+ and LS- with PhB. The proposed method is simple and rapid, and there is no use of toxic organic solvents. It was applied to the determination of anionic surfactants in commercial detergents, the results of which were in good agreement with those of the JIS titration method (Epton method).

Keywords: spectrophotometry; determination of ionic surfactants; Rose Bengal; Phloxine B; ion association of quaternary ammonium ion with anionic surfactants.


Regulating of bias voltage of a r.f.-powered glow discharge excitation source and the emission characteristics

Kazuaki Wagatsuma*

*Institute for Materials Research, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577

(Received 21 July 1998, Accepted 1 September 1998)

A method to control the bias voltage of r.f.-powered glow discharge plasmas was investigated to improve the detection power in optical emission spectrometry. D.C. voltages applied with an external power supply can induce greater voltage drops at the cathode sheath, thus leading to an increase in the sputtering rate. Further, the voltages also help promote excitation and ionization processes occurring in the plasma; therefore, the emission intensities excited by the plasma are elevated. The detection limit, which was defined as the sample concentration corresponding to three-times the standard deviation of the background intensity, was estimated to be 2.6×10-3 m/m% Cu in Fe-Cu binary alloys for Cu I 327.40 nm, when the Ar pressure, the r.f. power, and the d.c. external voltage were set at 800 Pa(6 Torr), 70 W, and 450 V, respectively.

Keywords: optical emission spectrometry; r.f.-powered glow discharge plasma; bias voltage control; self-bias voltage; emission intensity; detection limit.


Rapid determination of trace amounts of impurity metals in a Y-1 solution by graphite-furnace AAS using ascorbic acid as a matrix modifier

Kenji Fujiwara, Toshio Mori, Tomoko Atagi, Toshikazu Atagi, Hiroshi Mitsumata* and Taketoshi Nakahara**

*Electronics Research Laboratory, Corporate Technology Center, Matsushita Electronics Corporation, 1-1, Saiwai-cho, Takatsuki-shi, Osaka 569-1193
**Department of Applied Chemistry, Osaka Prefecture University, 1-1, Gakuen-cho, Sakai-shi, Osaka 599-8531

(Received 6 July 1998, Accepted 14 September 1998)

A ferroelectric material, Y-1, is made from a mixture (Y-1 solution) of Sr, Ta and Bi organic solvents. To determine impurity metals in this Y-1 solution, we required a pretreatment of wet digestion or dry ashing. Therefore, there was a possibility that impurity metals from the analytical environment and the digestion container might contaminate the Y-1 solution. In this work, we studied a method for the rapid determination of impurity metals (Al, K, Cr, Fe, Ni, Zn and Pb) in the Y-1 solution without using any pretreatment. Here, we used the calibration-curve method on GFAAS after diluting the Y-1 solution 1000 times by butyl acetate. However, the measurement on GFAAS was interfered by the matrix elements (Sr, Ta and Bi) in the Y-1 solution because their amount was 106 times that of the impurity metals. As a result of various examinations, it was found that ascorbic acid as a matrix modifier could prevent the matrix elements from interfering. The detection limits (3σ)of Al, K, Cr, Fe, Ni, Zn and Pb in the Y-1 solution were 25, 2, 6, 36, 9, 4 and 9 ng ml-1, respectively. We confirmed that the simple and rapid method could be used for determining impuriy metals in the Y-1 solution.

Keywords: Y-1 solution; calibration curve method; ascorbic acid; butyl acetate.


Technical Papers

Single-drop method for the determination of dodecylsulfate ion using an electrodeless piezoelectric quartz crystal

Toshiaki Nomura and Toshio Murakami*

*Department of Chemistry, Faculty of Science, Shinshu University, 3-1-1, Asahi, Matsumoto-shi, Nagano 390-8621

(Received 17 July 1998, Accepted 9 September 1998)

An electrodeless piezoelectric quartz crystal was constructed with a quartz plate placed on a horizontal metal plate electrode, where a single drop of electrolyte solution holding a platinum wire electrode was loaded. The quartz plate was oscillated with the connection of the electrodes to an oscillator. The frequency was shifted with the adsorption of the precipitate resulting from the reaction of calcium ion in the electrolyte solution with dodecylsulfate ion (SDS) in a sample solution dropped on the electrolyte solution. The frequency shifts resulting from the adsorption of the precipitate depended on the size of the drop, the size of the metal plate electrode, the composition of the electrolyte and the sample solutions. SDS over the range 5~100 µM could be determined with a relative standard deviation of 5.3% (n=5) for 50 µM. The adsorbing ion-pair of dodecylsulfate ion with cetyltrimethylammonium ion resulted in the determination of SDS over the range 0.2~10 µM with a good reproducibility of 6.8% of the relative standard deviation(n=4) for 5 µM.

Keywords : electrodeless piezoelectric quartz crystal; single drop method; dodecylsulfate ion; frequency change.


Notes

Amperometric determination of glutathione in yeast extract using a membrane-covered phthalocyanine embedded carbon-paste electrode

Hideaki Kinoshita*, Toyofumi Miya** and Shimeru Kamihira***

*Kwassui Women's College, 1-50, Higashi-yamate, Nagasaki 850-8515
**Technology Department, Saiki Factory of Kohjin Company, 11277, Higashihama, Saiki-shi, Oita 870-8580
***Department of Laboratory Medicine, Nagasaki University, 1-12-4, Sakamoto, Nagasaki 852-8501

(Received 23 July 1998, Accepted 4 September 1998)

By using an unmodified carbon electrode, a sulfhydryl compound can be detected in a potential region more positive than 400 mV vs. SCE, where currents by uric acid, phenols and NADH are also detected. A membrane-covered cobalt phthalocyanine embedded carbon-paste electrode(CoPCP electrode) allows the detection of glutathion(GSH) as low as 2 µM at 200 mV with practically no influence from coexisting substances in a biological sample, except for another sulfhydryl compound and ascorbic acid. The GSH contents in tweleve samples of yeast extract measured by a CoPCP electrode and those by a photometric method using glyoxalase I are in good agreement with the correlation coefficient of 0.96. The current by GSH increased 3.5 times with the addition of 5,5'-dithiobis-(2-nitrobenzoic acid)(DTNB), since the membrane pearmiability of GSH and TNB formed from DTNB by GSH are quite different from each other. Similarly,the current by yeast extract increased 3.5 times with the addition of DTNB. This result confirms that the current by yeast extract was practically due to GSH. The current due to cysteine was reduced by 13% upon the addition of DTNB.

Keywords: cobalt phthalocyanine; glutathione; yeast extract; membrane-covered electrode; amperrometry; sulfhydryl compound.


Technical Letters

Evaluation of simple and easy method for the preparation of a standard gas of volatile organic compounds from their mixed solution

K. Imamura, M. Eguchi, S. Ohira, T. Tashiro, S. Tadano, S. Tachibana, M. Tanaka, T. Nakahara, K. Hirai, Y. Fujikata, G. Fujise, Y. Maeda, Y. Yasaka and M. Warashina**

**Section of the 23rd Cooperative Test, Association for Environmental Analysis in Osaka, 1-8-4, Utsubohonmachi, Nishi-ku, Osaka 550-0004

(Received 21 July 1998, Accepted 8 September 1998)

Round-robin tests were conducted in order to investigate a simple and easy method for preparing a standard gas mixture of volatile organic hazardous air pollutants from their mixed solution by 16 members of the Association for Environmental Analysis in Osaka. Seven compounds (acrylonitrile, dichloromethane, chloroform, 1,2-dichloroethane, benzene, trichloroethylene, and tetrachloroethylene) were accurately weighed into a vial one by one. An aliquot of this liquid mixture was transferred into a glass vessel (1 or 2 l) using a microsyringe, and then vaporized. The resulting gas mixtures (about 300 ppm each) were evaluated as a first standard gas by gas chromatography. The obtained results prove this method to be accurate and precise for the preparation of a standard gas mixture.

Keywords: round robin test; preparation of standard gas; volatile organic hazardous air pollutants; gas chromatography.


Digest of Doctoral Dissertation

Nondestructive Analysis of Polymers by Raman Spectroscopy, Near-Infrared Spectroscopy, and Chemometrics

Masahiko Shimoyama

Forensic Science Laboratory, Hyogo Prefectural Police Headquarters, 5-4-1, Shimoyamate-dori, Chuo-ku, Kobe 650-8510

(Awarded by Kwansei-Gakuin University dated June 26, 1998)

The studies described in this thesis had three purposes. One was to demonstrate the potential of the Raman spectroscopy-chemometrics method and the near-infrared spectroscopy-chemometrics method in polymer analysis. Another was to correlate statistically detected spectral changes with known sample properties, such as the comonomer content, density, and crystallinity, and to predict the properties of polymers. Yet another was to propose band assignments for the Raman and near-infrared spectra of polymers with the aid of the second derivatives and the loadings plots obtained in chemometrics. The Raman spectroscopy-chemometrics method and the near-infrared spectroscopy-chemometrics method are promising for the in situ and nondestructive analysis of polymers. A multiplicative scatter correction (MSC) is powerful pretreatment to overcome the noise, intensity changes, and vertical drifts of the Raman and near-infrared spectra of polymer products, such as pellets. A principal component analysis (PCA) can discriminate the spectra of polymer samples with similar properties, while a partial least-squares regression (PLSR) can construct good calibration models, which can predict the properties of polymers. It has become clear that PCA and PLSR combined with the MSC treatment in Raman and near-infrared spectroscopies are useful for qualitative and quantitative analyses of polymer products and biological materials, such as ivory.

(Received October 29, 1998)

Keywords: nondestructive analysis; polymer; chemometorics; Raman spectroscopy; near-infrared spectroscopy; ivory; forensic science.


Development of Advanced Ion Chromatography with Silica-Based Stationary Phases

Kazutoku Ohta

National Industrial Research Institute of Nagoya, 1-1, Hirate-cho, Kita-ku, Nagoya-shi, Aichi 462-8510

(Awarded by Nagoya University dated October 31, 1997)

A study on the application of both a HPLC silica-based anion-exchanger (TSKguardgel QAE-SW) and unmodified silica gels to conventional IC was carried out for the development of advanced ion chromatography (IC) for anions and cations. First, IC for anions with an anion-exchanger was investigated. Good separation and highly sensitive indirect-UV detection for inorganic anions (HCO3-, Cl-, NO2-, NO3- and SO42-) were achieved by elution with either trimellitate or pyromellitate having strong eluent strength. This result indicates that some HPLC anion-exchangers are applicable to IC for anions when eluent ions having strong eluent strength are used. Second, IC for cations with unmodified silica gels was investigated. One kind of silica gel (Develosil 30-5) proved to act as a cation-exchanger under strongly acidic conditions. Good separation and highly sensitive conductimetric detection for common mono- and divalent cations (Li+, Na+, NH4+, K+, Mg2+ and Ca2+) was achieved by elution with either nitric acid/2,6-pyridinedicarboxylic acid or oxalic acid. The silica gel was also successfully applied to the ion-exclusion chromatographic separation of both aliphatic and aromatic carboxylic acids. Since it's cation-exchange property was attributed to be aluminium in the silica gel, a modification of silica gels with aluminium provided a newly advanced way to prepare novel silica-based cation-exchangers for IC. The IC methods developed here would contribute to expand the utility of IC for anions, cations and carboxylic acids.

(Received October 22, 1998)

Keywords: ion chromatography; anions; cations; carboxylic acid; silica-based anion-exchanger; unmodified silica gel; aluminium.


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