Vol. 52 No. 1
January, 2003
Kazuhiko Tsukagoshi1
1 Department of Chemical Engineering and Materials Science, Faculty of Engineering, Doshisha University, Kyotanabe-shi, Kyoto 610-0321
(Received 1 July 2002, Accepted 16 October 2002)The author has studied capillary electrophoresis-chemiluminescence detection system. Various types of the chemiluminescence detection cells for capillary electrophoresis were developed, including flow- and batch-type cells. The author took advantage of several chemiluminescence reagents such as luminol, peroxyoxalate, ruthenium(II) complex, and 1.10-phenanthroline in the system, and also introduced several separation modes such as micellar electrokinetic chromatography, capillary isoelectric focusing, and capillary gel electrophoresis to the system. Consequently, a variety of analytes including amino acids, peptides, proteins, saccharides, nucleic acids, nucleosides, metal ions, metal complexes, alkaloides, fluorescence compounds, fluorescence compound-including liposomes, and phenolic compounds were analyzed by means of capillary electrophoresis-chemiluminescence detection system. The system provided excellent selectivity and sensitivity. The sensitivity of the system was better than those of absorption and fluorescence detection systems; for example, the detection limit for luminol was 1.5×10-11 M (S/N=3), representing the highest sensitivity of luminol yet reported. The system was applied to microchip capillary electrophoresis and immunoassay. The author also considered on peak shape in batch-type chemiluminescence detection cell for capillary electrophoresis.
Keywords : capillary electrophoresis; chemiluminescence; separation; detection; selectivity; sensitivity.
Atsuko Hasegawa1
1 Kanagawa Environmental Research Center, 1-3-39, Shinomiya, Hiratsuka-shi, Kanagawa 254-0014
(Received 19 August 2002, Accepted 24 September 2002)An analytical method was developed for the determination of phthalate ester plasticizers {diisononylphthalate (DINP), diisodecylphthalate (DIDP) and diisotridecylphthalate (DITP)} in the atmosphere by liquid-chromatography/tandem mass spectrometry(LC/MS/MS). The ionization mode was positive-APCI (atmospheric pressure chemical ionization) and [M+H]+ ions were formed, which then fragmented by collosion with nitrogen. Sample air was drawn for 24 h at a constant flow rate (12~14 l/min) through a quartz fiber filter. After the collected substances were extracted into acetonitrile, di-(2-ethylhexyl)phthalate-d4 (DEHP-d4) was added as an internal standard. The recoveries, relative standard deviation (RSD) and limit of detection (LOD) were 94~102%, 4.3~8.7% and 0.05~0.8 ng/m3, respectively. DINP and DIDP were detected in outdoor and indoor air samples, including clearn room air; concentrations were 1.2~9.6 and 0.1~1.4 ng/m3, respectively. Because these phthalate esters are semi-volatile and include a mixture of many isomers, it is hard to obtain high analytical accuracy and precision by gaschromatograhy. The present method could be used to determine DINP and DIDP in air with high sensitivity.
Keywords : diisononylphthalate; diisodecylphthalate; diisotridecylphthalate; LC/MS/MS; air pollution.
Tadao Sakai1 and Tomohide Kitamura1
1 Department of Applied Chemistry, Aichi Institute of Technology, 1247 Yachigusa, Yakusa-cho, Toyota-shi, Aichi 470-0392
(Received 30 August 2002, Accepted 5 October 2002)A diprotic acid dye eosin and a tertiary amine quinine form a red 1:2 associate in neutral media. When trace amounts of cetylpyridinium salt are added to the media, in which the red 1:2 associate co-exists, one quinine is substituted for cetylpyridinium salt and a eosin-quinine-cetylpyridinium associate(1:1:1) is newly formed. Therefore, the extractability of cetylpyridinium ion is enhanced. As a result, a highly sensitive spectrophotometry can be developed for the determination of trace amounts of cetylpyridinium salt. The linearity of the calibration graph is good over the range of 2.5×10-7~1.5×10-6 mol dm-3 (=M) with an RSD of 0.37%. The proposed method can be applied to the trace analysis of cetylpyridinium salt and quaternary ammonium salts.
Keywords : ternary 1:1:1 associate; synergistic extraction effect; co-existence of eosin-quinine associate; cetylpyridinium salt.
Hiroshi Uchihara1, Atsushi Bando1, Satoshi Yoshida1, Masahiko Ikeda1 and Taketoshi Nakahara2
1 HORIBA Application Center, 2 Miyanohigashi, Kisshoin, Minami-ku, Kyoto-shi, Kyoto 601-8510
2 Department of Applied Chemistry College of Engineering Osaka Prefecture University, 1-1, Gakuen-cho, Sakai-shi, Osaka 599-8531
(Received 23 July 2002, Accepted 6 November 2002)When trace oxygen is analyzed by the method of inert gas fusion-infrared absorption, it is important to make a measurement immediately after the oxide on the surface of a sample has been removed. In general, file grinding, chemical polishing, and electrolytic polishing, etc. were done as a method for removing the surface oxide. However, oxide cannot be completely removed, because oxidation occurs immediately again after these procedures. The surface oxide begins reduction from 750°C by carbon in the graphite crucible of the inert gas fusion. The surface oxide was removed in the temperature range of 900°C~1050°C. At 1050°C or more, the sample had melted. Therefore, the sample was preheated for 60 seconds at 1000°C in an inert gas atmosphere in a graphite crucible. Afterwards, purified Sn was added using dual sample/flux introduction system. It was melted at 2300°C together with the sample, and the oxygen in the sample was measured. The interference of Mn as a getter of carbon monoxide in an oxygen analysis was eliminated by the addition of Sn, and an analysis of oxygen became possible after three minutes. An IR detector was installed in the absorption cell, whose length was five-times as long as that in the conventional model. The S/N was improved by five times. A sample of 2 g was analyzed using a large-volume graphite crucible. The analytical result of oxygen in a steel sample JSS GS-6b (oxygen concentration 3.4 µg g-1) became 2.9 µg g-1, except for the surface oxygen. JSS GS-2c (oxygen concentration 17.5 µg g-1) became 16.8 µg g-1, and both standard deviations was 0.2 µg g-1.
Keywords : trace oxygen in steel; surface oxide; interference suppression using tin flux; infrared method after fusion under inert gas; dual sample/flux introduction system.
Junya Kudo1, Yoshinori Takano1, Takeo Kaneko1 and Kensei Kobayashi1
1 Department of Chemistry and Biotechnology, Yokohama National University, 79-5, Tokiwadai, Hodogaya-ku, Yokohama 240-8501
(Received 30 August 2002, Accepted 11 November 2002)An extraction method for amino acids in soil samples to determine their concentrations and D/L ratios was developed. The amounts of amino acids extracted with a mixture of HF and HCl were much more than those extracted with hot water. Digestion of soil matrix with HF is necessary for extracting amino acids in soils. Since racemization of chiral amino acids occurred during extraction, different periods of HF extraction were employed to determine the initial D/L ratio. The extract was subjected to acid hydrolysis with 6 M HCl for 2 h to obtain free amino acids. The present procedure is promising to study amino acids in geological samples.
Keywords : amino acids; D/L ratio; extraction; racemization; soil samples.
Tomomi Watanabe1, Keiko Jyonosono1, Nobuaki Soh1, Toshihiko Imato1, Noriyuki Imazumi2, Masayuki Nakanishi2 and Jun-ichi Yagi2
1 Department of Chemical Systems and Engineering, Graduate School of Engineering, Kyushu University, 6-10-1, Hakozaki, Higashi-ku, Fukuoka 812-8581
2 Lubricants Research Laboratory, Idemitsu Kosan Co., Ltd 24-4, Anegasakikaigan, Ichihara-shi, Chiba 299-0107
(Received 23 August 2002, Accepted 21 October 2002)A spectrophotometric FIA method for the determination of the total base number (TBN) and the total acid number (TAN) in a lubricant, where a nonaqueous solvent (toluene 52%/H2O 1%/2-propanol 47%v/v) is used as an acid-base buffer solution, is proposed. The method is based on measurements of the absorbance change of an indicator contained in the acid-base buffer solution, which is generated due to a neutralization reaction of an acid or base in the lubricant with the acid-base buffer solution. For determining of TBN, a lubricant sample was injected into the carrier of the nonaqueous solvent and merged with a stream of perchloric acid (HClO4) solution prepared with the nonaqueous solvent. The base compound in the sample solution was neutralized with HClO4. An excess of HClO4 after the neutralization reaction was subsequently merged with a stream of tetrabutylammonium salt of trifluoroacetic acid (TFA·TBA) solution containing an indicator (m-cresol purple); the mixed stream was led to a spectrophotometric detector. As a result of mixing three streams, the composition of the TFA/TFA·TBA buffer changed. This change gave rise to an absorbance change of the acidic form of m-cresol purple at 536 nm. The absorbance change was monitored with a spectrophotometric detector, and a peak-shape signal was obtained for the base sample. An identical linear relationship between the peak height and the concentration of the base sample was obtained for several base additives of a lubricant, such as calcium sulfonate and calcium phenate etc, irrespective of their basicity. The TBN of a lubricant sample, which contained both base and acid additives, could be determined by the proposed method without interference from the coexistence of acid additives. A good linear correlation was found between the TBN obtained by our FIA method and that obtained by a conventional neutralization titration method. For the determination of that, a similar flow system to that for the determination of TBN was constructed from the streams of a carrier, a tetrabutylammonium hydroxide solution and tetrametylguanidine of hydrochloric acid solution containing α-naphtholbenzein. A single linear calibration line was obtained for several acid additives of a lubricant, such as zinc dialkyldithiophosphate and oleic acid. A good correlation for the analytical results of TAN was also obtained between the two methods. The proposed method was successfully applied to the determination of TBN and TAN of real lubricants with a sampling rate of 20 h-1, and solvent consumption was as low as 4.5 ml/sample.
Keywords : total base number; total acid number; lubricant; spectrophotometric FIA; pH buffer solution.
Toshihiro Suzuki1, Akiharu Hioki1 and Masayasu Kurahashi1
1 National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 3-10, 1-1-1, Umezono, Tsukuba-shi, Ibaraki 305-8563
(Received 13 September 2002, Accepted 15 November 2002)Solutions of cyanide ions of approximately 1000 mg kg-1 were prepared with 0.2~1.5 mol dm-3 KOH solutions and stored in high-density polyethylene and PFA bottles at 8°C and 25°C. The concentrations of the solutions were determined by a complexometric titration using a nickel titrant as a reliable reference and murexide as an indicator. The decreases in the concentrations were -1.7~-2.8%/year at 8°C and -19~-26%/year at 25°C. The higher was the KOH concentration, the smaller was the decrease in the cyanide concentration. The material of the bottle had no influence on the storage stability of the solution. The storage stability of potassium cyanide was similarly studied. The purity of potassium cyanide might decrease by more than 0.10%/year at 25°C, even if it is stored in an sealed bottle.
Keywords : cyanide ion; potassium cyanide; storage stability of standard solution; nickel; murexide.
Kunihiro Watanabe1, Takuya Okada1 and Masayuki Itagaki1
1 Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641, Yamazaki, Noda-shi, Chiba 278-5810
(Received 4 April 2002, Accepted 17 October 2002)The flow injection fluorometry of an ultra-trace amount of magnesium ion was investigated by an on-line concentration method using a PTFE tube. In a weak alkaline solution, magnesium ions were adsorbed and concentrated on the inner surface of a PTFE tube which had been treated with a 2 M NaOH solution for 3 hours at 70°C. Then, magnesium adsorbed on PTFE was eluted with 0.1 M HCl quantitatively, and then mixed with a N,N'-bis-salicylidene-2,3-diaminobenzofuran(SABF) dioxane solution and dimethylamine buffer. Magnesium ions reacted with SABF and formed a Mg-SABF complex in the flow tube, and was determined by on-line fluorometry. Although the presence of calcium ions interfered with the concentration of magnesium, it was removed by the addition of o,o'-bis(2-aminoethyl)ethyleneglycol-N,N,N',N'-tetraacetic acid(GEDTA) as a masking agent. The optimum conditions were as follows: inner diameter of PTFE tube, 0.5 mm; length of PTFE tube, 3 m; concentration pH, 10.3; sample flow rate, 2 ml/min; complexing pH, 10.4; concentration time, 3 min; carrier, 50% dioxane; measurement wavelength: Ex=475 nm, Em=545 nm. The detection limit was 82 ppt. The result for the determination of magnesium was 3.1 ppb in distilled water, which shows good agreement with the value obtained by ICP-AES.
Keywords : on-line concentration; adsorption on PTFE tube; magnesium(II); FIA; distilled water.
Kensaku Okamoto1,2, Akio Yasuhara1,3, Takeshi Nakano1,4, Katashi Kenmotsu1,5, Toru Matsumura1,6, Takao Yagi1,7, Kazutoshi Kakita1,8, Akihiro Ono1 and Mamoru Sakata1
1 The Japan Society for Analytical Chemistry, 1-26-2, Nishigotanda, Shinagawa-ku, Tokyo 141-0031
(Received 29 August 2002, Accepted 26 September 2002)There is an important discussion on the condition of alkaline treatment in case of determination of PCBs in soil/sediment; that is, the official method at present which consists of alkaline treatment of sample over 80°C as pretreatment process will cause dechlorination of PCBs. A study group of the Japan Society for Analytical Chemistry has been organized to improve it. The proposed conditions against the official method (method A) were; extraction using acetone (method B) or toluene (method C) is followed by alkaline treatment of the extract at room temperature instead of at 80°C. Hexane extraction and chromatographic clean-up procedure after alkaline treatment in method B and method C are same as method A. An interlaboratory comparison test was performed by participation of 7 laboratories. As the result, there are no significant difference in quantitative data obtained from 3 methods except high values in 1~3 Cl-substituted homologues from method C. Study on rate of dechlorination of PCB homologues has not programmed in this experiment.
Keywords : PCBs; river sediment; alkaline treatment; GC/MS analysis.
Hideaki Kitami1, Tetsuo Watanabe2, Takio Kitahara3, Yoshimi Ishihara3 and Jiro Takano3
1 Sougou Kankyou Bunseki Co., Ltd., 1-13-2, Kamoi, Midori-ku, Yokohama 226-0003
2 Department of Resources and Environmental Science, School of Humanities and Culture, Tokai University, 1117, Kitakaname, Hiratsuka-shi, Kanagawa 259-1292
3 Derpartment of Chemistry, School of Science, Tokai University, 1117, Kitakaname, Hiratsuka-shi, Kanagawa 259-1292
(Received 8 July 2002, Accepted 3 October 2002)A simple and low cost mesurement method for determination of bisphenol A (BPA) in drinking water and river water by high-performance liquid chromatography (HPLC) with an ultraviolet detecter (UV) has been studied. As a result, good linearity of the calibration curve was obtained in the concentration range from 0.01 mg/l to 1 mg/l. The detection limit, based on S/N=3, was 0.0065 µg/ml for BPA. Acetone was recommended for the elution of BPA from the solid phases. The recoveries for BPA from river water spiked at a mesurement concentration of 0.1 mg/l was 55.3~78.7%, and the relative standard deviations was 5.2~7.1% by an activated carbon column method. This measurement method could be successfully applied to the determination of BPA in drinking water and river water.
Keywords : HPLC/UV; bisphenol A (BPA); drinking water; river water; extraction.
Kiyoshi Imamura2, Masaharu Eguchi2, Syuhei Ohira2, Tadashi Shirakuni2, Norimichi Takenaka2, Takahisa Tashiro2, Shigeo Tachibana2, Kyouzo Hirai2, Yutaka Fujikata2 and Yuta Yasaka2
2 Section of the 23rd Cooperative Test, Association for Environmental Analysis in Osaka, 1-8-4, Utsubohonmachi, Nishi-ku, Osaka 550-0004
(Received 9 September 2002, Accepted 30 October 2002)Keywords : roundrobin test; HPLC; aldehyde; DNPH.
Shingo Saito
Department of Applied and Environmental Chemistry, Kitami Institute of Technology, 165, Koen-cho, Kitami-shi, Hokkaido 090-8507
(Awarded by Tohoku University dated September 12, 2001)Analytical methods of LnIII were developed in which the kinetic inertness of LnIII complexes with acyclic polyaminocarboxylate (PAC) on the dissociation reaction was the key to establishing detection systems. First, a pre-derivatization HPLC method with fluorescent detection was developed for closed-shell LnIII using an aromatic octadentate PAC as the derivatizing reagent. Selective detection at ppb levels was achieved. Second, the factors to form inert Ln-PAC complexes were investigated on the dissociation reaction. The rate constants and activation parameters were determined for a series of LnIII-hexadentate and octadentate PAC complexes. Interestingly, an unusually large negative activation entropy for solvolysis governed the kinetic inertness, and was probably derived from metal envelopment in the complex and hydration on the activation state. Third, a novel measurement method of the dissociation rate was developed using capillary electrophoresis (CE). The dissociation rate constant for the CeIII-PAC complex was determined for the first time. Fourth, based on the result of the second study, a sensitive pre-derivatizing CE method for LnIII at the fmol level was developed using an aromatic EDTA derivative. In this method, a high resolution was achieved by introducing a ternary complex equilibrium in the carrier. Finally, the energy-transfer luminescence of a TbIII complex with a PAC possessing phenol function was studied. The detection limit at the ppt level was achieved, and the photophysics was also investigated.
(Received September 20, 2002)Keywords : lanthanide(III); polyaminocarboxylate complex; dissociation kinetics; HPLC; capillary electrophoresis; energy transfer.
Hiromitsu Hachiya
DKK·TOA Corporation, R&D Center, Sensor Technology dept., 613, Kita-Iriso, Sayama-shi, Saitama 350-1388
(Awarded by Tokyo Metropolitan University dated March 25, 2002)The downsizing of electrochemical gas sensors that hold an electrolyte solution with a gas-permiation membrane using microfabrication technologies was studied. These sensors can be used for sensing toxic gases down to the ppm level. The first sensor developed was a micro Cl2 gas sensor of 5×5×3(mm). It consisted of a Pyrex glass body, Pt/Ti electrodes, a porous silicon membrane, an electrolyte solution and the other components. This sensor gave a rapid response and linearity up to the 10 ppm level of Cl2. The volume of the electrolyte became 1/250; Pt volumes for working and counter electrodes were 1/2500000, 1/20000, respectively, when this micro sensor was compared with commercial centimeter-size sensors. This first model sensor had a large pore-size membrane, which showed some problem concerning evaporation of the electrolyte solution. Then, a second model micro Cl2 sensor of 3×4×1(mm) was developed. This sensor had a multi layer structure, including an original gas-permeation mechanism, and showed a reliable property to give stable signals at low concentration. A micro HCN sensor was also developed. Ag/Pt/Ti electrodes on a glass body as working and counter electrodes were newly designed and prepared. Satisfactorily good performances up to 20 ppm HCN were obtained. These sensors were the first micro electrochemical type for toxic gases. This study might have provided a possible approach to achieve micro toxic gas sensors.
(Received October 22, 2002)Keywords : micro sensor; electrochemical; chlorine; hydrogen cyanide; toxic gas.
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