Vol. 4 9, No. 1
January, 2000
Keiji Saito* and Toshio Ogawa**
*UBE Scientific Analysis Laboratory, Inc., 1978-5, Kogushi, Ube-shi, Yamaguchi 755-8633
**Laboratory for Ecological Polymer and Organic materials, Kanazawa Institute of Technology, 7-1, Ohgigaoka, Nonoichi, Ishikawa-gun, Ishikawa 921-8501
A computer program for the identification of additives included in polymers has been developed by combining MS, 1H-NMR, 31P-NMR and LC/MS. Some empirical equations are presented for calculating the existence probabilities of certain additives. This method was confirmed to be applicable to the identification of various additives in polymers.
Keywords : computer-assisted identification; additives; MS spectra; 1H-NMR spectra; 31P-NMR spectra; LC/MS spectra.
Tomokazu Tanaka, Jun Kuramata, Mikio Seki and Masataka Hiraide*
*Department of Molecular Design and Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603
(Received 9 August 1999, Accepted 29 September 1999)The proposed technique uses laser energy to directly sample solid material and to transfer it as a fine aerosol to an acidic solution for analysis by ICP-MS. Multi-element synthetic standard solutions are employed instead of standard reference solid materials for calibration. The surface of sintered silicon nitride was subjected to ablation for 3 min using a Q-switched Nd/YAG laser (150 mJ) operating at 1064 nm. Laser-sampled particles were carried in an argon stream to 10 cm3 of 0.1 M nitric acid, which was analyzed by ICP-MS for impurity metals. The sample collected in the solution was determined by ICP-AES and found to be about 50 µg. This indicates that the particle-transport efficiency is about 7%. The proposed method is more rapid and convenient than conventional methods involving sample decomposition prior to instrumental analysis. It has been successfully applied to the determination of Mg, Ti, Mn, Co and W in a sintered body of silicon nitride.
Keywords : ICP-MS; laser ablation; sintered silicon nitride; advanced ceramics; direct analysis.
Akinori Isozaki, Hiroto Shimamura, Yukitoki Morita*, Hisomu Nagashima** and Tadao Okutani*
*Department of Materials and Applied Chemistry, College of Science and Technology, Nihon University, 1-8-14, Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8308
**Institute of Science and Technology, Inc., 3-10-2, Kitashinagawa, Shinagawa-ku, Tokyo 140-0001
A new method for the determination of azide ion has been developed for ion chromatography with a graphitized carbon column and suppressed conductivity detection. 1 (v/v)% acetonitrile containing 1.5 mM sodium carbonate and 0.5 mM tetrabutylammonium hydroxide (TBA-OH) was used as the optimal mobile phase for the simultaneous determination of a mixture of eight anions (F-, Cl-, NO2-, Br-, N3-, NO3-, SO42- and HPO42-). These were efficiently separated within 20 minutes, and azide ion was eluted in about 7 minutes between bromide ion and nitrite ion. The calibration curve of the azide ion was linear with correlation coefficients of more than 0.999. The relative standard deviation of the peak areas was 0.89% at 5 mg/l, and 4.7% at 100 µg/l. The detection limit (S/N=3) of azide ion was about 5 µg/l. This method was applicable for the determination of azide ion in water samples.
Keywords : azide ion; ion chromatography; graphitized carbon column; tetrabutylammonium hydroxide.
Hideo Asakura, Katsushige Ikegami* and Hisanobu Wakita**
*Research Center, Shinagawa Refractories Co., Ltd., 707, Imbe, Bizen-shi, Okayama 705-8577
**Department of Chemistry, Faculty of Science, Fukuoka University, 8-19-1, Nanakuma, Jonan-ku, Fukuoka 814-0133
In order to analyze spinel raw materials by X-ray fluorescence spectrometry we applied JRRM800 series reference materials prepared by the Technical Association of Refractories, Japan. The standard deviation (SD) of the calibration curves, obtained by using JRRM800 series glass beads, are very satisfactory: less than 0.1 mass% for the main components and less than 0.02 mass% for impurities. The obtained reproducibilities (within-laboratory) amply satisfied the permissible tolerance of each component in JIS R 2014 (method for chemical analysis of Al2O3-MgO). This analysis method could be applied to the determination of Al2O3 from 95 to 50 mass% in commercial spinel raw materials. From the analytical results, it was shown that these spinels were made from synthetic and/or natural raw materials of both alumina and magnesia sources.
Keywords : JRRM800 series; reference material; X-ray fluorescence spectrometry; spinel; glass bead.
Kazuko Hirayama and Kei Kameoka*
*Industrial Research Center of Ehime Prefecture, 487-2, Kumekubota, Matsuyama-shi, Ehime 791-1101
(Received 20 September 1999, Accepted 26 October 1999)Acrylic acid and the acrylamide were radically polymerized with (NH4)2S2O8 in a phosphate buffer containing lysozyme, surface-modified silica beads, and cross-linkeres. A polymer layer having a recognition site to lysozyme on a silica-gel surface was formed using a molecular imprinting technique. The modified silica gel was able to grasp lysozyme selectively compared with non-modified silica gel. Even after an operation of binding and releasing of lysozyme to the modified silica-gel has been repeated several times, the rebinding ability does not decrease. A sensor that use the quartz crystal microbalance method, which involves a polymer layer having a recognition site to lysozyme, was made. The quartz crystal was coated with a polymer layer having a recognition site to lysozyme and set to the cell. When a lysozyme aqueous solution was dropped onto the cell, good sensitivity and response were shown. It turns out that it can be used as a sensor film.
Keywords : molecular imprinting; molecular recognition; polymer particles; zeta-potential; lysozyme.
Keiro Higuchi*2, Ryozo Goto*3, Takuji Kawashima*4, Koichi Oguma*5, Akira Kawase*6 and Hisako Ogura*7
*1 Report on the Japanese Association for Flow-Injection Analysis (No. 1)
*2 Tokyo Kasei Kogyo Co. Ltd., 6-15-9, Toshima, Kita-ku, Tokyo 114-0003
*3 TOA Electronics Ltd., 1-29-10, Takadanobaba, Shinjuku-ku, Tokyo 169-8648
*4 Department of Chemistry, University of Tsukuba, 1-1-1, Tennoudai, Tsukuba-shi, Ibaraki 305-8571
*5 Department of Materials Technology, Faculty of Engineering, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba 263-8522
*6 Seiko Instruments Inc., 1-8, Nakase, Mihama-ku, Chiba 261-0023
*7 Chiba Prefectural Laboratory of Water Pollution, 3-5-1, Inagekaigan, Mihama-ku, Chiba 261-0005
In order to propel the standardization of the flow-injection analysis (FIA) method and to estimate the reliability of FIA, interlaboratory testing for the determination of nitrite and nitrate in standard solutions and river-water samples was carried out at five laboratories belonging to the Japanese Association for Flow-Injection Analysis of the Japan Society for Analytical Chemistry. Because little difference was found in the experimental conditions for FIA employed at respective laboratories, normalization of the analytical conditions should be easy to establish. The relative standard deviation for repeatability tests with ten injections were less than 0.90% for nitrite and less than 1.76% for nitrate, respectively, using prepared standard samples. The analytical results for nitrite and nitrate in water samples obtained by the FIA method were in good agreement with those obtained by the standard method. The regression equation for nitrite was y=0.9983x+0.0158 (r=0.9901, n=69), and that for nitrate: y=1.0107x+0.0424 (r=0.9933, n=72).
Keywords : flow-injection analysis; nitrite determination; nitrate determination; interlaboratory testing river-water.
Yoshikazu Nakamoto*
*Tokuyama Refinery, Idemitsu Kosan Co., Ltd., 1-1, Singu-cho, Tokuyama-shi, Yamaguchi 745-0843
(Received 26 May 1999, Accepted 22 September 1999)Organic and inorganic arsenic compounds in thermally cracked gasoline are known to be catalyst poisons in the aromatization process. Therefore, it is important to determine trace arsenic in thermally cracked gasoline. By the addition of nickel nitrate as a matrix modifier, a simple and rapid method was established for the determination of arsenic in thermally cracked gasoline by using graphite-furnace AAS. The determination limit and relative standard deviation were estimated to be 10 ng g-1 and 3.1% for a 100 ng g-1 arsenic determination, respectively. The effects of the kinds of thermally cracked gasoline and other metals were not observed.
Keywords : arsenic; matrix modifier; nickel nitrate; graphite furnace AAS; thermally cracked gasoline.
Yuichiro Hashimoto, Masuyoshi Yamada, Masao Suga, Kouichi Kimura, Minoru Sakairi*, Shinji Tanaka, Mamoru Mizumoto** and Masami Sakamoto***
*Hitachi, Ltd., Central Research Laboratory, 1-280, Higashi-koigakubo, Kokubunji-shi, Tokyo 185-8601
**Hitachi, Ltd., Power & Industrial Systems R & D Laboratory, 832-2, Horiguchi, Hitachinaka-shi, Ibaraki 312-0034
***Hitachi, Ltd., Instrument Division, 882, Ichige, Hitachinaka-shi, Ibaraki 312-8504
Real-time monitoring for trace gas has become increasingly important in environmental analysis. Until now, gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) have been used for trace-gas analysis. However, these methods require much time and cost. We coupled atmospheric-pressure chemical ionization (APCI) with an ion-trap mass spectrometer (ITMS) for the purpose of trace-gas detection in flue gas. By this method, the detection limit of chloroaromatic compounds, such as chlorophenol and chlorobenzene, has become 10~1000 times as low as that by other ionization methods, such as electron impact (EI) and chemical ionization (CI). For example, the detection limit of 2,4-dichlorophenol is 30 ppt. By using APCI-ITMS, the detection of chlorophenols in flue gas has been proved to be possible.
Keywords : atmospheric-pressure chemical ionization; ion-trap mass spectrometer; trace-gas analysis; real-time monitor; chlorophenol; chlorobenzene.
Eiko Nakamura and Michiko Yagi*
*Department of Environmental Sciences, Faculty of Education and Human Sciences, Yokohama National University, 79-2, Tokiwadai, Hodogaya-ku, Yokohama, 240-8501
(Received 23 July 1999, Accepted 12 October 1999)Spectrophotometric methods of cyanide with pyridine-pyrazolone, isonicotinic acid-pyrazolone and pyridine-barbituric acid have been widely known. Although they are very sensitive, they also have the following disadvantages. In the former two methods used as JIS methods, pyrazolone is insoluble in water, or pyridine has an unpleasant odor. In the latter one used as standard methods, the absorbance decreases with time after the maximum absorbance is reached. In the present work, color development with isonicotinic acid-sodium barbiturate, which is soluble in water and odorless reagents, was studied. The concentration of isonicotinic acid and sodium barbiturate as well as the pH, temperature and time affect the color development. When an isonicotinic acid(4%)-sodium barbiturate(1%) solution was used at pH 4~6, the maximum absorbance was achieved within 20 min and the absorbance was stable for 30 min at 25°C. The proposed procedure is as follows. Ten milliliters of acetate buffer solution(0.1 M, pH 5) and 0.5 ml of chloramine T solution(1%) are added to a sample, and the solution is left standing for 5 min. Then, 10 ml of an isonicotinic acid(4%)-sodium barbiturate(1%) solution is added to the solution. After the solution is made up to 50 ml with water, it is left for 30 min at 25°C. The absorbance is measured at 595 nm. The sensitivity of this method is about 1.3-times that of the JIS methods. The isonicotinic acid-sodium barbiturate solution is easily prepared by dissolving with water and is stable for 20 days at room temperature.
Keywords : spectrophotometric determination of cyanide; isonicotinic acid-sodium barbiturate.
Hiroki Ohura*, Toshihiko Imato**, Ikuo Matsuo and Sumio Yamasaki*
*Department of Industrial Chemistry, Faculty of Engineering, Kyushu Sangyo University, 2-3-1, Matsugadai, Higashi-ku, Fukuoka 813-8503
**Department of Chemical Systems and Engineering, Graduate School of Engineering, Kyushu University, 6-10-1, Hakozaki, Higashi-ku, Fukuoka 812-8581
A simple and rapid potentiometric FIA method for the sequential determination of Cr(VI) and Cr(III) is described, using both a redox electrode detector and a stream of an Fe(III)-Fe(II) potential buffer containing bromide. A three-channel flow system, a carrier stream (water), a reagent stream (H2SO4 solution or Ce(IV) solution containing H2SO4) and the Fe(III)-Fe(II) potential buffer solution, was constructed by equipping a six-way valve between the stream of the reagent solution and the carrier stream. The valve was used to switch the stream of either the H2SO4 solution or the Ce(IV) solution containing H2SO4 in the reagent solution. For the selective determination of Cr(VI) in a mixed sample of Cr(VI) and Cr(III), the valve was switched to flow a reagent stream of the H2SO4 solution into the potential buffer solution. Then, Cr(VI) reacted with the potential buffer, and a peak signal was obtained by the detector. For determining the total chromium, the sum of Cr(VI) and Cr(III), the valve was switched to flow the reagent stream of Ce(IV) solution into the potential buffer solution. Cr(III) in the mixed sample was oxidized to Cr(VI) by Ce(IV) in the reagent stream and a peak signal was obtained by the detector. Cr(III) in the mixed sample was determined by the difference of the peak heights obtained by the two reagent streams. The detection of Cr(VI) was based on the measurement of a large transient potential change due to bromine generated by an oxidaton reaction between Cr(VI) and bromide in the potential buffer solution. The linear relationships between the peak heights and the sample concentration were observed over the range of 1×10-6 to 10×10-6 M for Cr(VI) and from 4×10-6 to 4×10-5 M for Cr(III) by using a 0.01 M Fe(III)-Fe(Il) potential buffer containng 0.6 M NaBr and 3.6 M H2SO4.
Keywords : Cr(VI)-Cr(III) speciation; flow injection analysis; potentiometry; redox electrode.
Motoshi Nakamura, Tomoko Yasukawa, Tetsuya Igarashi, Shinkichi Yamada and Sen-ichi Aizawa*
*Faculty of Engineering, Shizuoka University, 3-5-1, Johoku, Hamamatsu-shi, Shizuoka 432-8561
(Received 1 June 1999, Accepted 22 September 1999)A fluorometric determination method for asulam(methyl4-aminosulphonylcarbamate, herbicide) in environmental water samples by using solid-phase extraction(SPE) has been proposed. The method is based on the addition of EDTA to a sample solution for the elimination of interferences from metal ions and the use of ethylsilanized silica(tC2) and polystyrene gel (PS-2) combination cartridges to remove any fluorescent impurities in the matrix. Asulam in a sample solution(pH 2~3) was hardly retained in the tC2 combined upon the PS-2, and retained in the PS-2. Asulam, which was slightly adsorbed on the tC2, was retained in the PS-2 by washing with 20 ml of water. Asulam was then eluted from the PS-2 with 2 ml of methanol. After adjusting the pH to 8~10 and diluting to 10 ml, asulam was determined by measuring the fluorescence intensity at 343 nm with excitation at 252 nm. The calibration graph was linear over the range of 0.02 to 0.3 mg l-1 (r=0.997). The average recovery of 0.25 mg l-1 asulam in 100 ml of distilled water was 98.9% (n=5) with a relative standard deviation of 1.16%. The proposed method has been successfully applied to some environmental water samples with recoveries of 93~96%.
Keywords : asulam; fluorometry; solid-phase extraction; environmental waters.Makoto Sato
Sagamihara R&D Center, Shino-Test Corporation, 2-29-14, Oonodai, Sagamihara, Kanagawa 229-0011
(Awarded by Tohoku University dated March 25, 1999)The potential neurotoxicity of transferrin-bound aluminium has recently received increasing attention. A simple, sensitive, and selective method has been developed for the determination of transferrin-bound aluminium with 8-quinolinol by using affinity chromatography combined with kinetic differentiation mode HPLC. The most remarkable point of this method is that only transferrin-bound aluminium ion selectively response among many metal ions in human serum. The complex formation of released aluminium with 8-quinolinol is completed on the first column, which has an affinity to transferrin. The aluminium chelate is separated from the serum matrix on the second column, and detected at Ex 370 nm, Em 504 nm. It is well recognized that zinc is one of the important elements for human body. Although analytical applications of porphyrin as a highly sensitive spectrophotometric reagent for zinc have been investigated, the reaction of metal ion with porphyrin is generally very slow. In order to overcome this difficulty, several accelerators such as nucleoside were reported. In this study, it was found that zinc-TCPP (α,β,γ,δ-tetrakis (4-carboxyphenyl) porphine) complex is quantitatively formed within 20 min at room temperature in the presence of adenine. This effect has been successfully applied to the determination of zinc in human serum by HPLC. These proposed methods reported here will provide simple, rapid yet and sensitive techniques for trace elements of medical and environmental importance.
(Received October 9, 1999)Keywords kinetic differentiation mode liquid chromatography; micellar liquid chromatography; serum; aluminium; 8-quinolinol; transferrin; affinity chromatography; zinc; porphyrin.
Akihiko Ishida
Division of Molecular Chemistry, Graduate School of Engineering, Hokkaido University, Nishi-8, Kita-13, Kita-ku, Sapporo-shi, Hokkaido 060-8628
(Awarded by Tohoku University dated March 25, 1998)The importance of simple analytical methods that require no sophisticated instruments is increasing. For simple measurements, visual methods based on the perception of color change and the recognition of figure are more suitable. The author has developed simple methods for the visual determination of trace metal ions, based on construction of the following chemical systems. First, for the visual sensitive detection of trace aluminium, a simple concentration method was developed. After a drop of solution are evaporated on a hydrophobic substrate, components, such as several pH buffers or poly(vinyl alcohol), form a ring-like solid phase. Aluminium ion was concentrated into the ring as a fluorescent chelate of 2,2'-dihydroxyazobenzene and distinctly detected. This method has been successively applied to the determination of ppb levels of aluminium in tealeaves. Second, a color-forming reaction system has been developed, which makes it possible to visualize the concentration of metal ions by using a color property of the Xylenol Orange (XO)-metal complex system. The Xylenol Orange-Fe(III) system gives yellow, red, and purple blue along with an increase in the iron concentration, owing to a sequential formation of FeIII(xo) and FeIII2(xo). A field test for iron leached from rock samples was developed by using the color reaction, and was applied to the prediction of water quality in aquifers.
(Received October 14, 1999)Keywords test method; visual determination; colorimetry; visual fluorometry; 2,2'-dihydroxyazobenzene; aluminium(III); poly(vinyl alcohol); Xylenol Orange; iron(III).
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