Vol. 55 No. 9
September, 2006
Takaaki Okamoto1, Keiichi Fukushi1, Kuriko Yokota2, Sahori Takeda3 and Shin-ichi Wakida3
1 Faculty of Maritime Sciences, Kobe University, 5-1-1, Fukaeminami-machi, Higashinada-ku, Kobe-shi, Hyogo 658-0022(Received 14 April 2006, Accepted 19 July 2006)
We developed capillary zone electrophoresis (CZE) with indirect UV detection for the determination of phosphate in seawater using transient isotachophoresis (TITP) as an on-line concentration procedure. As a high-UV-absorbing compound in a background electrolyte (BGE), 2,6-pyridinedicarboxylic acid (PDC) was used. Hydroxypropyl methylcellulose (HPMC) was added to the BGE to suppress electroosmotic flow (EOF) and the dispersion of an analyte zone for the purpose of maximizing the concentration effect by TITP. Several analytical conditions were examined to separate low concentrations of phosphate from high concentrations of chloride and sulfate in seawater and to detect phosphate with high sensitivity. The following optimum conditions were established: BGE, 5 mmol/l PDC containing 0.01% HPMC adjusted to pH 3.5 with 1 mol/l sodium hydroxide; wavelength for detection, 200 nm; vacuum (5 in. Hg) injection period of sample, 1 s (ca. 21 nl); terminating ion solution, 500 mmol/l 2-(N-morpholino)ethanesulfonic acid (MES) adjusted to pH 4.0 with 1 mol/l sodium hydroxide; vacuum injection period of the terminating ion solution, 30 s (ca. 630 nl); applied voltage, 15 kV with the sample inlet side as the cathode. Phosphate in seawater samples was detected for approximately 15 min. The limit of detection (LOD) for phosphate was 32 µg/l (PO43--P) at a signal-to-noise ratio of three. The respective values of the relative standard deviation (RSD) of the peak area, peak height, and migration time for phosphate were 2.1, 2.3, and 0.81%. The proposed method determined phosphate in surface seawater samples.
Keywords : seawater analysis; phosphate; capillary zone electrophoresis; transient isotachophoresis; indirect detection.
Emiko Yoshida1, Harumi Takegami1 and Masakazu Horie1
1 Saitama Prefectiral Institute of Public Health, 639-1, Kamiokubo, Sakura-ku, Saitama-shi, Saitama 338-0824(Received 22 April 2006, Accepted 7 July 2006)
A simple and rapid method has been developed for the determination of miloxacin (MLX) and its principal metabolite, M-1 {5,8-dihydro-8-oxo-2H-1,3-dioxolo(4,5-g)quinoline-7-carboxylic acid}, in fish by high-performance liquid chromatography (HPLC) with fluorescence detection. MLX is extremely unstable in aqueous solution toward light, and is rapidly converted to its demethoxy derivative, M-1. The drugs were extracted from fish with 0.2% metaphosphoric acid-acetonitrile (6 : 4, v/v), and the extracts were cleaned up on an Oasis HLB cartridge (60 mg). HPLC separation was performed on a Wakosil II 5C18-RS column (150×4.6 mm i.d.) using 25 mM phosphate buffer (pH 2.5)-acetonitrile (70 : 30, v/v) as the mobile phase at a flow rate of 0.6 ml/min. The calibration graphs for both compounds were rectilinear from 0.02 to 1 µg/ml. The recoveries of the compounds from fish fortified at a level 0.1 µg/g were 80.0~96.0%, with high precision. The limits of determination of the compounds in fish were 0.01 mg/g.
Keywords : miloxacin; quinolones; fish; high-performance liquid chromatography.
Tomohiro Yamashina1, Jong-Soo Lee2 and Yutaka Itabashi3
1 Division of Marine Life Science, Chair of Bioresources Chemistry, Graduate School of Fisheries Sciences, Hokkaido University, 3-1-1, Minato-cho, Hakodate-shi, Hokkaido 041-8611(Received 13 April 2006, Accepted 5 August 2006)
A convenient method for the determination of the stereochemical configuration and alkyl groups of natural 1-O-alkylglycerols was developed. For this purpose, 1-O-alkylglycerols were converted into bis-3,5-dinitrophenylurethane (DNPU) derivatives, followed by chiral-phase high-performance liquid chromatography (HPLC). Complete enantiomer separation was achieved using two columns (25 cm×4.6 mm i.d., 5 µm particle size) having chiral phases of opposite configurations, N-[(S)-1-(1-naphthyl)ethylaminocarbonyl]-(S)-tert-leucine and N-[(R)-1-(1-naphthyl)ethylaminocarbonyl]-(R)-tert-leucine, which caused a reversal in the order of enantiomer elution. The analysis was optimized by using a ternary mobile phase, hexane-dichloromethane-ethanol, and detection at 254 nm. Chiral-phase HPLC in conjunction with electrospray ionization mass spectrometry (ESI-MS) of the derivatives was carried out using an ion-trap mass spectrometer. Post-column addition of 2-propanol was used to assure electrospray ionization in the negative mode. The spectra showed a prominent fragment [M-DNPU]- ion, by which individual molecular species could be identified. This method was standardized with synthetic 1-O-, 2-O- and 3-O-hexadecyl-sn-glycerols (16 : 0) and was applied to the identification and quantification of individual molecular species of enantiomeric 1-O-alkylglycerols derived from muscle lipids from a deep-sea teleost fish, Stromateus Stellatus. The results clearly showed that the glycerol moieties in all of the alkylglycerols have the S-configuration (1-O-alkyl-sn-glycerols), and that the major alkyl groups are 16 : 0, 18 : 1, 14 : 0 and 18 : 0. The method demonstrates that the chiral-phase HPLC in conjunction with ESI-MS provides unambiguous information about the chirality and the alkyl groups of natural alkylglycerols.
Keywords : alkylglycerol; alkyldiacylglycerol; 3,5-dinitrophenylurethane; enantiomer; chiral-phase HPLC; electrospray ionization mass spectrometry; Stromateus Stellatus.
Harumi Takegami1, Masakazu Horie1 and Hiroyuki Nakazawa2
1 Saitama Prefectural Institute of Public Health, 639-1, Kamiokubo, Sakura-ku, Saitama-shi, Saitama 338-0824(Received 25 April 2006, Accepted 30 June 2006)
A simple and reliable method using liquid chromatography-electrospray ionization-mass spectrometry (LC/ESI-MS) has been developed as an analytical method of macrolide antibiotics, such as erythromycin, oleandmycin, kitasamycin, josamycin, mirosamicin, neospiramycin, spiramycin, tilmicosin and tylosin in milk. The drugs were extracted with acetonitrile, and the extracts were cleaned up by partition with hexane. The extracts were analyzed using LC/MS. The LC separation was performed on a TSK-gel Super ODS column (100 mm×2 mm i.d.) with a gradient system of 0.2% acetic acid-acetonitrile as the mobile phase. MS acquisitions parameters were established in the positive ESI mode, and the related molecular ions were (M+2H)2+ or (M+H)+. The recoveries of the drugs from milk fortified at a level 0.1 mg/g were 63.8~95.9% with high precision. The limits of detection of the drugs in milk were 0.01 mg/g.
Keywords : macrolide anticbiotics; erythromycin; oleandmycin; kitasamycin; josamycin; mirosamicin; neospiramycin; spiramycin; tilmicosin; tylosin; milk; LC/MS.
Mariko Yoshimura1, Koichi Inoue1, Tomoyuki Hanaoka2, Pan Guowei3, Ken Takahashi4, Yuko Yamano5, Yusuke Iwasaki1, Rie Ito1, Koichi Saito1, Shoichiro Tugane2 and Hiroyuki Nakazawa1
1 Department of Analytical Chemistry, Hoshi University, 2-4-41, Ebara, Shinagawa-ku, Tokyo 142-8501(Received 9 May 2006, Accepted 27 July 2006)
Phthalate esters (PEs) are widely used as industrial plasticizers in the production of polyvinyl chloride and other plastics. Recent studies on human exposure are required to develop an analytical method for measuring monoester metabolites of PEs in human urine samples. In the present study, we developed an accurate and selective analytical method for the simultaneous determination of phthalate monoester metabolites, such as mono-buthyl phthalate (MBP) and mono-2-ethylhexyl phthalate (MEHP), in urine by using LC/MS/MS accompanied by solid-phase extraction. The developed method was applied to occupational exposure to urine in order to assess human exposure due to environmental circumstance. The average value of each MBP and MEHP for working exposure subjects was significantly higher than that of normal subjects. Furthermore, a good correlation was observed between MBP and MEHP in all of the urine samples.
Keywords : Phthalate esters; monoester metabolites; occupation exposure; LC/MS/MS.
Naoto Kamiya1, Tomoyuki Takayanagi1, George Hirabayashi1 and Kazuharu Sugawara1
1 Faculty of Education, Gunma University, 4-2, Aramaki, Maebashi-shi, Gunma 371-8510(Received 14 April 2006, Accepted 20 July 2006)
The voltammetric behavior of oligosaccharides, which combine with wheat germ agglutinin (WGA), was investigated. The binding was evaluated from the change in the electrode response of an oligosaccharide labeled with an electroactive compound. When the measurement of the labeled oligosaccharide was carried out in a 0.1 M phosphate buffer (pH 7.0) with WGA, the peak current decreased based on the WGA-labeled oligosaccharide binding. In the presence of WGA, the peak current of labeled chitotriose was lower than that of labeled cellotriose. This is because the hydrophobic acetylamide group of chitotriose relates to the binding. Furthermore, the binding constant between WGA and oligosaccharide was estimated.
Keywords : oligosaccharide; wheat germ agglutinin; electroactive compound; voltammetry.
Kanako Honda1, Yasuro Niidome2, Hirofumi Kawazumi1 and Sunao Yamada2
1 Department of Engineering, Kinki University, Kyushu, 11-6, Kayanomori, Iizuka-shi, Fukuoka 820-8555(Received 24 April 2006, Accepted 21 July 2006)
The irradiation of a pulsed laser (532 nm 10 Hz, 10 mJ/pulse) on dodecanethiol-passivated gold nanoparticles in cyclohexane resulted in the deposition of gold nanoparticles onto a glass substrate. The mode values and the spreads of the size distribution of the laser-deposited gold nanoparticles could be controlled with the initial size of colloidal gold nanoparticles and the laser irradiation time. The initial gold nanoparticles of 2 nm and the 1-minute laser irradiation resulted in large deposited gold nanoparticles (mode value, 16 nm; distribution spread, 9.1 nm). The larger initial gold nanoparticles (20 nm) and the longer laser irradiation (5 minutes) provided the fragmentized deposition of gold nanoparticles (mode value, 10 nm; distribution spread, 7.7 nm) which showed a linear correlation between the peak shifts of localized surface plasmon bands and the refractive indexes of the surrounding solvents.
Keywords : gold nanoparticles; laser-induced deposition; localized surface plasmon resonance.
Akinori Matsuda1 and Kouichi Tsuji1
1 Department of Applied Chemistry, Graduate School of Engineering, Osaka City University, 3-3-138, Sugimoto, Sumiyoshi-ku, Osaka-shi, Osaka 558-8585(Received 7 April 2006, Accepted 5 July 2006)
We proposed and investigated the X-ray fluorescence analysis of a micro-volume inside a sample by using needle-type collimators. The primary X-rays were passed into a needle-type collimator, and the inside of the soft sample was irradiated. Generated X-ray fluorescence was detected through a similar collimator. Standard samples of agar that included elements with certain concentrations were prepared. The analytical performance was evaluated using those standard samples. The lowest limits of detection of K, Ca, and Zn in agar were 154 mg/kg, 85.4 mg/kg, and 5.95 mg/kg, respectively. Moreover, oyster was measured as an application to a biological sample. It was confirmed that X-ray fluorescence analysis inside sample was possible.
Keywords : XRF; micro-volume analysis; needle-type collimators; inside sample.
Satoru Miyata1, Akira Tanji1, Hisanori Imura1, Hideaki Matsue2 and Chushiro Yonezawa2,3
1 Ibaraki University, Department of Environmental sciences, 2-1-1, Bunkyo, Mito-shi, Ibaraki 310-8512(Received 14 April 2006, Accepted 28 July 2006)
The k0-standardization method of instrumental neutron activation analysis (INAA) by research reactors, JRR-3 and JRR-4, was evaluated by determining the reference materials associated with air pollution, {NIST SRM 1633a (Coal Fly Ash), NIES CRM No.8 (Vehicle Exhaust Particulates), and NIST SRM 2783 (Air Particulate on Filter Media)}. The analytical results of NIST SRM 1633a obtained by different facilities of the reactors were consistent with each other, and the deviation from certified (reference) values for 22 elements were within 5% and 11 elements within 3%. It was ascertained that the present k0 INAA is very accurate. This method was applied to aerosol samples taken in Ibaraki prefecture during Oct. 2004 to Mar. 2005. Trace-element contents in particulate matter with different sizes were determined, and the size distribution and the regional variation were revealed.
Keywords : instrumental neutron activation analysis; k0 standardization method; aerosol; non-destructive analysis; multi-element determination.
Tomo Takeda1, Ikuko Oyane1, Kenji Okitsu1, Masakazu Furuta2, Hiroshi Bandow1, Rokuro Nishimura1 and Yasuaki Maeda1
1 Graduate School of Engineering, Osaka Prefecture University, 1-1, Gakuen-cho, Sakai-shi, Osaka 599-8531(Received 14 April 2006, Accepted 18 July 2006)
Many kinds of toxic compounds are emitted in the environment from human activity. It has already been reported that various compounds can be decomposed by ultrasonic irradiation. However, there have been few studies regarding the toxicity of the compounds produced by sonochemical decomposition. Therefore, it is important to investigate the effects of sonochemical decomposition products on environmental microorganisms. In this study, the growth activity of yeast cells in growth media containing toxic compounds and their sonochemical decomposition products was measured by a calorimetric analysis. The calorimetric analysis could provide not only quantitative information for the microbial growth activity, but also the characteristic features about the bactericidal and bacteriostatic effects of the chemicals on microbial cells. The growth curves of yeast cells, measured by calorimetry, showed that chloroacetone (MCA) affected the growths of yeast cells. In addition, in the presence of MCA of over 450 ppm, the growth of yeast cells could not be observed. In the case of the sonochemical decomposition products of MCA (initial concentration; 500 ppm), the peak of growth thermograms of yeast cells shifted towards a shorter incubation time. The growth curve of the cells with 6 hours sonicated sample of MCA was similar to that observed without MCA, suggesting that the toxicity of MCA on the growth of yeast cells decreased according to the decomposition of MCA.
Keywords : calorimetry; sonochemical decomposition product; toxic compound; yeast cell.
Yasutaka Joichi1, Narong Lenghor2, Toshio Takayanagi2, Mitsuko Oshima2, Shoji Motomizu2 and Nobuo Ura3
1 Faculty of Science, Okayama University, 3-1-1, Tsushimanaka, Okayama-shi, Okayama 700-8530(Received 18 April 2006, Accepted 4 July 2006)
Flow injection analysis (FIA) systems with low power consumption and personal-computer control were developed by using solenoid pumps and an LED detector. Both programs for controlling the system and acquiring measurement data were written using LabVIEW. The FIA system was applied to the determination of nitrite ion in river-water samples based on diazotization and coupling reactions. Linear calibration graphs were obtained with the combination of pump(s) and photometric detector in the concentration range of nitrite ion at 0.5~3.0×10-6 M. Nitrate and nitrite ions were also determined simultaneously by the system by using a Cd/Cu reduction column and a by-pass flow. Determination of ammonia in river-water samples was also realized by the system with a modified indophenol reaction.
Keywords : Flow injection analysis; LabVIEW control; solenoid pumps; nitrate ion; nitrite ion; ammonia.
Takako Yamamoto1, Akhmad Sabarudin2, Osamu Noguchi2, Toshio Takayanagi2, Mitsuko Oshima2 and Shoji Motomizu2
1 Faculty of Science, Okayama University, 3-1-1, Tsushimanaka, Okayama-shi, Okayama 700-8530(Received 2 May 2006, Accepted 21 July 2006)
An automatically controlled collection/concentration system for ICP-AES was developed. Elements were collected with small chelating disks and chelating resin with the iminodiacetate moiety packed in a line filter. This column was installed in a 6-way valve on the pretreatment system, which could be connected on line to ICP-AES. The flow rate was 1 ml min-1 and conditioning of the chelating disk was carried out by flowing 0.5 M ammonium acetate (pH 5.5) for 2 min, sampling for 5 min and washing for 1 min. Elution was done by passing through 2 M HNO3 at 1.3 ml min-1 for 1 min. Bi, Cd, Co, Cr, Cu, Mn, Ni, Pb and V could be determined with 5.0 ml of the sample solution. The enrichment factors were 3~15 times and the collection efficiencies were better than 80%. The detection limits (LOD) were from 0.003 for Mn to 0.311 for Bi, which were several 10 to 100-times lower than that of normal LOD of ICP-AES. This method was successfully applied to the determination of these metals in tap and river-water samples.
Keywords : automated collection/concentration; chelating disk and chelating resin; ICP-AES; heavy metals.
Ken'ichi Jinno1,2, Tokuo Shimizu1 and Nobuo Uehara1
1 Department of Applied Chemistry, Faculty of Engineering, Utsunomiya University, 7-1-2, Yoto, Utsunomiya-shi, Tochigi 321-8585(Received 13 April 2006, Accepted 18 July 2006)
Phenol was listed as an item to be monitored for preserving aquatic life on November, 2003. The lowest guide-line value was set at 10 mg/l in a trout special area. Studies of the analytical method that is used to determine phenol and chlorophenols by solid-phase extraction and derivatization GC/MS clarified the following: a 500 ml water sample adjusted below pH 4 was passed to a solid-phase extraction cartridge; after elution and enrichment, phenol and chlorophenols were derivatized with pentafluorobenzyl bromide and determined by GC/MS. The detection and quantitation limits of phenol and chlorophenols by the proposed method were 0.016~0.024 mg/l and 0.048~0.071 mg/l, respectively. Using the proposed method, the concentrations of phenol and chlorophenols in river water sampled at 20 sites in Tochigi prefecture were determined. The results show that the concentration range of phenol is between ND and 0.39 mg/l. Except for 2,4-dichlorophenol at one site, no chlorophenols were detected.
Keywords : phenol; chlorophenols; GC/MS; solid-phase extraction; derivatization.
Masaharu Shiki1 and Koichi Yamamoto1
1 Department of Materials Science, Yonago National College of Technology, 4448, Hikona-cho, Yonago-shi, Tottori 683-8502(Received 30 March 2006, Accepted 29 June 2006)
A spectrophotometric method utilizing chitosan coprecipitation for the determination of trace iron(II) was examined with 1,10-phenanthroline (phen) and tetrabromophenolphthalein ethyl ester (TBPE). Iron(II) reacted with phen to a stable cheleting complex, [Fe(phen)3]2+. [Fe(phen)3]2+ associated with TBPE- buffered at about pH 6.5 to form the ion associate [Fe(phen)3]2+·(TBPE-)2. A chitosan solution dissolved with acetic acid was added to this solution and chitosan precipitated from the solution immediately. The ion associate [Fe(phen)3]2+·(TBPE-)2 was adsorbed onto the chitosan precipitate. After centrifugation, the supernatant solution was discarded. The chitosan precipitate was dissolved with acetic acid and sodium acetate, and iron(II) could be determined by measuring the absorbance of the solution at 606 nm, that is, the maximum absorption wavelength of TBPE without any pretreatment. The detection limit (S/N=3) was about 8 ppb. The relative standard deviations (n=3) for 60 ppb iron(II) was 3.9%. This method is simple for the determination of iron(II) at less than 60 ppb, and there is no use of toxic organic solvents.
Keywords : spectrophotometry; Fe(II)-1,10-phenanthlorine; tetrabromophenolphthalein ethyl ester; ion associate; chitosan coprecipitation.
Chikako Yamazaki1, Naoko Suzaki1, Masahiro Nakao1, Shinichiro Kamino1, Takako Yamaguchi1 and Yoshikazu Fujita1
1 Osaka University of Pharmaceutical Sciences, 4-20-1, Nasahara, Takatsuki-shi, Osaka 569-1094(Received 14 April 2006, Accepted 19 June 2006)
A novel spectrophotometric method was established for the determination of chlorpromazine (CPZ) and its related drugs. The method is based on ternary complex formation among o-sulfophenylfluorone, molybdenum(VI) and CPZ. In the determination of CPZ, Beer's law is obeyed in the range of 0.2~7.0 µg ml-1. The effective molar absorptivity at 525 nm and the relative standard deviation were 4.6×104 dm3 mol-1 cm-1 and 2.4% (n=6), respectively. The method was successfully applied to assays of CPZ and its related drugs in pharmaceutical preparations. The proposed method, requiring no solvent extraction, should be useful for a simple and sensitive determination of CPZ and its related drugs.
Keywords : chlorpromazine; chlorpromazine related drugs; spectrophotometry; o-sulfophenylfluorone-molybdenum(VI); ternary complex formation.
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