Vol. 54 No. 2
February, 2005
Takashi Yokoyama1, Michio Zenki1, Miroslav Macka2 and Paul R. Haddad2
1 Department of Chemistry, Faculty of Science, Okayama University of Science, 1-1, Ridai-cho, Okayama-shi, Okayama 700-0005(Received 26 July 2004, Accepted 28 September 2004)
An enhancement of the separation selectivity of inorganic ions by capillary electrochromatography was investigated. When a sulfo-betain-type zwitterionic surfactant as an additive in a background electrolyte (BGE) was used, the separation selectivity of the hydrophobic inorganic anions in 10 inorganic anions (chloride, bromide, iodide, iodate, nitrite, nitrate, chlorate, perchlorate, thiocyanate, and molybdate ions) and 7 cations {lithium, sodium, potassium, rubidium, cesium, magnesium, and cerium(III) ions} could be changed. The magnitude of the selectivity change was evaluated from the association constants (Kass) between the zwitterionic surfactants {3-(N,N-dimethyldodecylammonio)propane sulfonate and 3-(N,N-dimethylmyristylammonio)propane sulfonate} micelles and the inorganic ions. The largest Kass value was 800 dm3 mol-1 for the perchlorate ion among the 10 inorganic anions. The perchlorate ion could also be used an the additive in the BGE for a selectivity change of the inorganic anions. On the other hand, the Kass values for the 7 inorganic cations were small compared to those for the inorganic anions. When carboxylate ions and amines as additives in the BGE were used, the separation selectivity of copper(II) in 5 transition-metal ions {iron(II), cobalt(II), nickel(II), copper(II), and zinc(II) ions} could be signiticantly changed. The magnitude of the selectivity change was also evaluated from the stepwise coordination constants (KCuL1 and KCuL2) between [Cu(phen derivative)2]2+ (phen=1,10-phenanthroline) pre-complexed copper(II) with the phen derivatives and the carboxylate ions in the BGE and between the Cu(II)-Alizarin complexone complex anion formed by an on-line complexation and the amines in the BGE. The mechanism of the separation selectivity was considered based on the KCuL1 and KCuL2 values. Furthermore, when pyridinedicarboxylates (PDCs) as chelate reagents for the on-line complexation were used, the separation selectivity of cobalt(II) and copper(II) could be changed. The migration orders were cobalt(II)<copper(II) and copper(II)<cobalt(II) for both 2,3- and 2,5-PDC and 2,4-PDC, respectively. This result was considered based on the structures of the metal PDC complexes.
Keywords : inorganic ion; selectivity; capillary electrochromatography; zwitterionic surfactant; chelate reagent.
Kunihiro Watanabe1, Youhei Katou1 and Masayuki Itagaki1
1 Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641, Yamazaki, Noda-shi, Chiba 278-8510(Received 13 April 2004, Accepted 22 September 2004)
A novel flow-through electrochemical cell, used to concentrate and separate successively lead(II) and zinc(II) ions, has been developed. The working electrode potential can be controlled by the solution resistance of the present electrochemical cell, which is a stepladder type. The flow channel between the working and counter electrodes in the cell is made of a PTFE tube (inner diameter 1.0 mm). The potential gradient on the working electrode depends on the PTFE tube length. After lead and zinc were deposited at -0.1 V and -1.0 V vs. SSE, respectively, on a working electrode of platinum wire for 20 min, they were eluted from the working electrode for 3 min at +1.0 V. The sample solutions, involving zinc(II) and lead(II) ions, were prepared with distilled water and sodium perchlorate as a supporting electrolyte. The zinc(II) and lead(II) ions dissolved from the working electrode were determined with 4-(2-pyridylazo)-resorcinol (PAR) by spectrophotometry at a wavelength of 520 nm. The calibration curve for the zinc(II) ion was linear at a concentration below 100 ppb. The determination limit of zinc was 4 ppb using 1 ml of the sample solution. On the other hand, the calibration curve between the absorbance and the lead concentration was not straight, but the calibration curve between the lead concentration and the peak area was linear over the concentration range below 1000 ppb.
Keywords : flow-through electrochemical cell; solution resistance; simultaneous determination; spectrophotometry; lead; zinc.
Yoshinori Shimada1, Ryuji Mizoguchi2, Hidenori Shinohara3, Tomoyuki Yatsuhashi3 and Nobuaki Nakashima3
1 Institute for Laser Technology, 2-6, Yamada-oka, Suita-shi, Osaka 565-0871(Received 12 August 2004, Accepted 8 October 2004)
For the first time, femtosecond laser mass spectrometry (FLMS) has successfully detected 1,3,6-trichlorodibenzo-p-dioxin and 2,2',5-trichlorobiphenyl. Non-chlorinated dibenzo-p-dioxin and biphenyl were also compared with the results of trichlorinated dioxins. The formation of parent ions without heavy fragmentation is an important goal for laser mass spectrometry; in other words, a high signal intensity ratio value of the parent ions/total ions (P/T ratios) is essential. The ratios were found to depend on the laser intensities as well as the wavelengths in FLMS. Generally, dioxins were more highly fragmented with increases in the laser intensity for all compounds studied here; the P/T ratios of non-chlorinated dioxins were higher with increases in the laser wavelength. The wavelength dependency for the chlorinated compounds was not distinct, probably because C-Cl bonds are easily dissociated in high-intensity laser fields, which induce further fragmentation. As a consequence of dissociation, the P/T ratios of the chlorinated dioxins were lower than the non-chlorinated dioxins. Within our experimental parameters, the optimum laser conditions were 1500 nm excitation with an intensity of 3.0×1013 W/cm2 for 1,3,6-trichlorodibenzo-p-dioxin and 2000 nm and 3.3×1013 W/cm2 for 2,2',5-trichlorobiphenyl.
Keywords : femtosecond laser; high intensity; mass spectrometry; polychlorinated dioxins; non-resonance multiphoton ionization.
Yusuke Iwasaki1, Koichi Inoue1, Rie Ito1, Yoshihiro Yoshimura2, Koichi Saito1 and Hiroyuki Nakazawa1
1 Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Hoshi University, 2-4-41, Ebara, Shinagawa-ku, Tokyo 142-8501(Received 4 August 2004, Accepted 19 October 2004)
Allantoin is a catabolic product of purines, which is formed by the enzymatic reaction of uricase with uric acid. Investigations of the residual existence of allantoin in the human body have revealed the presence of trace levels of allantoin in human biological samples. However, the hitherto available analytical techniques for allantoin in biological samples suffer from such problems as insufficient separation from coexisting substances and a non-specific detection wavelength of 220 nm. Therefore, an accurate, sensitive and selective analytical method for the determination of allantoin in human biological samples using hydrophilic interaction chromatography with mass spectrometry (HILIC/MS) was developed. The following were used for HILIC/MS: AtlantisTM HILIC Silica column, electrospray ionization (ESI), negative mode, and selected ion monitoring (SIM) with m/z 157 for allantoin and m/z 159 for allantoin-1,3-15N2. The detection limit (S/N=3) and the quantification limit (S/N=10) were 0.03 and 0.1 µM, respectively, and the calibration curve (0.1~10 µM) showed linearity with a correlation coefficient (r) of 0.999. The average recoveries of allantoin with an internal standard in human serum, urine and saliva samples were 96.9% (RSD: 13.2%), 95.2% (RSD: 9.0%) and 100.3% (RSD: 11.8%), respectively. The proposed HILIC/MS method for the determination of allantoin can be applied to the detection of trace amounts of allantoin in human biological samples.
Keywords : hydrophilic interaction chromatography; MS; allantoin.
Noboru Hiraki1, Akinori Isozaki2 and Hisomu Nagashima3
1 Tokyo Kaseigakuin high school, 22, Sanbanchou, Chiyoda-ku, Tokyo 102-8341(Received 30 July 2004, Accepted 27 September 2004)
A method for the determination of iodine in organic compounds has been developed for ion-pair chromatography (IP-HPLC) with a new C30 column, coupled with a UV detector at 230 nm. A phosphate buffer (pH 6.0) containing 2 mM tetrabutylammonium (TBA-HSO4) in 15(v/v)% acetonitrile was used as an optimal mobile phase for iodide ion. Especially the calibration curve was linear with excellent correlation coefficients of more than 0.9995; further, the relative standard deviations at 20 and 2 µg/ml were less than 0.27 and 0.45% based on 10 repeated measurements. This method was applied to the determination of iodine in organic compounds with an oxygen-flask-combustion method. Several mg of a sample was burned in an oxygen flask filled with 20 ml of 2 mM NaHCO3 and 100 ppm NH2NH2 as an absorbent; water was added to make 50 ml. A 20 mg liquid sample solution was injected into a column. The content of iodine by this method was in good agreement with that calculated based on the molecular weight.
Keywords : ion-pair chromatography; iodine in organic compounds; UV detector; C30-silica column.
Takashi Karatsu1, Daisuke Iwata1, Toshiharu Nakajima1, Shiki Yagai1, Masanori Seimiya2, Fumio Nomura2 and Akihide Kitamura1
1 Department of Applied Chemistry and Biotechnology, Faculty of Engineering, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba-shi, Chiba 263-8522(Received 13 September 2004, Accepted 3 October 2004)
The development of instant determinations of glucose has attracted much attention from the viewpoint of diabetic treatment. We propose a determination by using FT-IR with an attenuated total-reflection method (ATR). However, it is not easy to obtain accurate values of the concentrations of glucose in serums. In order to obtain a high correlation coefficient (R) between the concentrations obtained by the FT-IR-ATR method and those obtained by the enzyme method, we improved the method, for example, by changing the shape of the sample holder, and developed an extraction method of the absorption band from the background by using of a second-ordered differential method. Finally, we obtained R=0.807, which opened a possibility of using the FT-IR-ATR method for the instant determination of glucose.
Keywords : glucose; serum; FT-IR; ATR.
Yukako Taoka1, Saori Ishioka1 and Yutaka Itabashi1
1 Laboratory of Bioresouces Chemistry, Graduate School of Fisheries Sciences, Hokkaido University, Hakodate-shi, Hokkaido 041-8611(Received 29 May 2004, Accepted 4 October 2004)
A simple and sensitive method for the determination of molecular species of bacterial phosphatidylglycerols (1,2-diacyl-sn-glycero-3-phospho-1'-sn-glycerol, PG) as an intact form is described. The PG fraction isolated from Escherichia coli IAM12119 was subjected to reversed-phase high-performance liquid chromatography (HPLC) in conjunction with ion-trap mass spectrometry with electrospray ionization (ESI-MS). The HPLC analysis was performed with an ODS column (25 cm×4.6 mm i.d., 5 µm particle size) using methanol/water/aqueous ammonium hydroxide (93:7:0.1, v/v/v) as the mobile phase, which gave a clear resolution of individual molecular species containing saturated, monounsaturated and cyclopropane fatty acids. In addition to a prominent deprotonated [M-H]-molecule, the negative ESI-MS gave weak product ions, [M-RCO]-, [M-H-RCOOH]-and [RCOO]-, by which individual molecular species could be identified. These product ions, derived from a fatty acid at the sn-2 position, showed greater intensities than those from the sn-1 position.
Keywords : phosphatidylglycerol; molecular species; acyl position; Escherichia coli; reversed-phase HPLC; electrospray ionization mass spectrometry.
Kazutoshi Nose1, Takaharu Kondo2, Shuki Araki3 and Takao Tsuda4
1 Department of Materials Science & Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya-shi, Aichi 466-8555(Received 20 May 2004, Accepted 23 October 2004)
Since both acetone and β-hydroxybutyrate are metabolized compounds from acetoacetate, the relationship between the concentrations of acetone and β-hydroxybutyrate in gases released from human skin and blood, respectively, were studied. For collecting gases released from human skin, a home-made collector was used. The collector was a bag-type (inner volume, 70 ml), which was made with sheets of perfluoro (ethylene/propylene). After a finger was pushed into the collector at the center of a shield film made by PARAFILM®, its state was maintained for a period of 3 minutes for collecting human emanated gases from the inserted finger. Then, the acetone concentration in the collector was estimated by gas chromatography. We found a good relationship between them. Its correlation factor was 0.88 (p<0.01). The concentration of acetone can be used as an alternative marker for β-hydroxybutyrate in blood. The present proposed method for estimating the ketone-value is non-invasive, and its sampling procedure is very easy.
Keywords : gases emanated from human skin; non-invasive; acetone; β-hydroxybutyrate.
Yo-ichi Ishibashi1, Shozo Asada1, Hiroyuki Igaki1, Shu-ichi Yamada1, Satoshi Tsuruta1, Makoto Shimura1, Kazutoshi Kakita1, Akihiro Ono1 and Mamoru Sakata1
1 The Japan Society for Analytical Chemistry, 1-26-1, Nishigotanda, Shinagawa-ku, Tokyo 141-0031(Received 5 July 2004, Accepted 13 September 2004)
The Japan Society for Analytical Chemistry carried out a second proficiency testing on the determination of dioxins (polychlorodibenzo-p-dioxins, polychlorodibenzofurans and coplanar polychlorobiphenyls) in fly-ash of a waste incinerator, the same as the 1st one. The proficiency testing of analytical laboratories is based on ISO/IEC Guide 43-1, “Proficiency testing by interlaboratory comparisons”. This testing was carried out in the term from June '01 to August '01 with the participation of 71 laboratories. The test results were; 1.747 ng-TEQ/g of total Dioxin concentration on average, 11% in robust coefficient of variation. There have only been 3 labs estimated to be unsatisfactory because of their large z score in the robust method, over 3 in absolute value.
Keywords : proficiency testing; dioxins; fly-ash; GC-MS analysis.
Keiichi Fukushi1, Jun-ichi Tsujimoto2 and Kuriko Yokota1,3
1 Faculty of Maritime Sciences, Kobe University, 5-1-1, Fukaeminami-machi, Higashinada-ku, Kobe-shi, Hyogo 658-0022(Received 28 June 2004, Accepted 17 September 2004)
We have determined the concentrations of inorganic components in jellyfish, such as Aurelia aurita (with and without aeration), Stomolophus nomurai, and dried sludge of Aurelia aurita using absorptiometry, flame photometry, ICP emission spectroscopy, atomic absorption spectrometry, or ion chromatography to examine the potential usefulness of jellyfish as a fertilizer for vegetable fields. The concentrations of the total nitrogen (9800 µg/kg), total phosphorus (19000 µg/kg), magnesium (17000 µg/kg), and calcium (27000 µg/kg) in the dried sludge of Aurelia aurita were 23, 1360, 14, and 96-times higher than those in Aurelia aurita (without aeration, 420, 14, 1200, and 280 µg/kg in fresh weight), respectively. Although the dried sludge of Aurelia aurita seemed to have some potential as a fertilizer, it contained high concentrations of iron (190000 µg/kg) and aluminum (2200 µg/kg), which might be undesirable for the growth of plants. On the other hand, the concentration of total nitrogen (750 µg/kg) in Stomolophus nomurai was 1.8-times higher than that in Aurelia aurita (without aeration), although the concentrations of total phosphorus (2.3 µg/kg) and calcium (75 µg/kg) were 1/6 and 1/4 of those in Aurelia aurita (without aeration). Stomolophus nomurai could also be expected to have potential as a fertilizer. Spinach was cultivated using a suspension of Aurelia aurita and Stomolophus nomurai, and the dried sludge of Aurelia aurita as a fertilizer. Stomolophus nomurai was most effective for the growth of spinach. The high concentrations of iron and aluminum in the dried sludge of Aurelia aurita seemed to decelerate the growth of spinach.
Keywords : jellyfish; inorganic constituents; nutrients; fertilizer; vegetables.
Takahira Tokimoto
Department of Chemistry, The University of Arizona, 1306 E. University, Tucson, Arizona 85721
(Awarded by Osaka University dated March 25, 2004)
A novel method, named two-phase sheath flow/fluorescence microscopy, was developed to investigate the initial stage of fast reactions at a liquid/liquid interface. The organic phase was flowed from a micro-capillary inserted into the aqueous sheath flow, and formed a cylindrical flow, of which the diameter was 5~20 µm. An excitation laser beam was irradiated to the organic phase flow through a microscope objective, and the emitted fluorescence was detected with an ICCD camera, or a streakscope. The rate of fast complexation at a liquid/liquid interface was measured. A digital simulation, in which the diffusion, complexation, and interfacial adsorption constants were incorporated, was used to analyze the reaction kinetics. It was revealed that the complexation of zinc(II) with 5-octlyoxymethyl-8-quinolinol was delayed by the dissolution of water into the 1-butanol phase just after the contact of two phases (0.1~2 ms). In the synergistic extraction of samarium(III) with 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione (Htta) and tri-n-octylphosphine oxide (topo), the reaction intermediate, Sm(tta)3(topo)(H2O)2 was successfully detected by means of a fluorescence lifetime measurement at the initial stage of complexation (1~30 µs). The lactone cleavage reactions of rhodamine dye at the liquid/liquid interface were investigated by two-photon excitation fluorescence microscopy. The rate constants of the cleavage reaction at the interface were determined.
(Received August 30, 2004)
Keywords : liquid/liquid interface; two-phase sheath flow; fluorescence microscopy; complexation kinetics; fast reaction rate.
Hideo Hayashi
Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science, 1-3, Kagurazaka, Sinjuku-ku, Tokyo 162-8601
(Awarded by Nagoya University dated March 25, 2004)
Inductively coupled plasma mass spectrometry (ICP-MS) offers a powerful analytical method. The mass spectral interferences, however, often become a serious problem. To overcome this problem, a low-pressure helium-ICP was studied for the ionization source. This helium plasma was generated in a water-cooled plasma torch. In order to minimize the background spectra, a sampling orifice was fabricated from aluminum metal. An aqueous sample-introduction technique was developed. The sample solution was converted into tiny droplets with an ultrasonic nebulizer, and then dried in a heater. The resulting dried aerosol was successfully introduced into the plasma through a PTFE capillary tube. Other sample-introducing techniques were examined, including electrothermal vaporization and laser ablation. The detection limits were measured based on 3σ for a wide range of elements in the periodic table. Improved lower detection limits were obtained for halogens, C, Cr, Fe, Se, and so on. The diagnosis of helium plasma with a Langmuir probe indicated that the plasma temperature was higher than that of the conventional argon plasma, which may contribute to an enhancement of the detectability. The analytical capability of the proposed ICP-MS was demonstrated by analyzing various types of certified reference materials.
(Received September 16, 2004)
Keywords : ICP-MS; helium plasma; trace analysis; electrothermal vaporization; laser ablation.
Haruka Minowa
Radioisotope Research Facility, The Jikei University School of Medicine, 3-25-8, Nishi-shinbashi, Minato-ku, Tokyo, 105-8461
(Awarded by Tokyo Metropolitan University dated March 25, 2003)
Pallasite meteorites, which are classified into stony-iron meteorites, have a unique structure that olivine grains are included in iron-nickel metal. They have been considered to be formed by the mixing of olivine mantle and metallic core at the core-mantle boundary in a differentiated asteroid. A study of such small planetary bodies gives us information of early formation and differentiation processes of rock-type planets, like Mars or Earth. The purpose of this study was to present the detailed formation process of the pallasite parent body based on trace elemental abundances in pallasite meteorites. For rare earth elements (REEs) and platinum group elements (PGEs), an analytical technique based on neutron activation analysis with extraction chromatography was developed. This new method enables the quantitative determination at the ppt level for REEs (La, Ce, Nd, Sm, Eu, Gd, Tb and Lu) in only 100 mg samples. REE data of this work in olivines from six pallasites, classified in main group pallasite, indicate that primordial REE patterns for pallasites are not so-called “V-shaped”, but linear light REE-depleted patterns. The formation scenario expected from trace elemental data is that a pallasite parent body experiences partial melting and subsequent large-scale melting. This scenario is consistent with the core-mantle mixing model for the formation of pallasite meteorites.
(Received August 30, 2004)
Keywords : pallasite meteorites; differentiation; neutron activation analysis; rare earth element.
Yasuhiro Suzuki
National Research Institute of Police Science, 6-3-1, Kashiwanoha, Kashiwa-shi, Chiba, 277-0882
(Awarded by Nagoya University dated April 30, 2004)
The analysis of trace impurities in various types of physical evidence was investigated by ICP-AES and ICP-MS. The obtained date were applied to forensic discriminations of the physical evidence, such as glass bottles, lead shotgun pellets, lead-tin solders and arsenous acids. A small amount (10~250 mg) of these samples was dissolved using acids, such as HF, HClO4, HNO3 and HCl, and several elements contained as trace impurity were analyzed by ICP-AES or ICP-MS. Trace impurities useful for the discrimination of each evidential material were selected after qualitative analyses of commercially available products. Satisfactorily good accuracy and precision were achieved in the analyses of NIST Standard Reference Materials for glass, lead shotgun pellets and solders. The analytical results for arsenous acid were estimated by comparing the data obtained by the present method and those by the JIS method; the concentrations for Sb and Pb showed good agreement between the two methods. The 5 trace impurities (Se, Sn, Sb, Pb, Bi) in arsenous acids could be determined with RSDs between 0.9% and 5.5%. The comparison of trace impurities was significantly useful to discriminate evidential materials made of the same substance, when the concentrations of the trace impurities exhibited quite large variations among samples from different origins and differences in the elemental compositions at different sampling positions were sufficiently small within the same samples.
(Received October 5, 2004)
Keywords : forensic science; physical evidence; trace impurity analysis; ICP-AES; ICP-MS.
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