Vol. 55 No. 2
February, 2006
Noboru Kitamura1
1 Division of Chemistry, Graduate School of Science, Hokkaido University, Kita 10-Nishi 8, Kita-ku, Sapporo-shi, Hokkaido 060-0810(Received 1 August 2005, Accepted 9 November 2005)
The analysis of individual microparticles in solution is in general very difficult because of their vigorous Brownian motions. Furthermore, the experimental results observed by a particle-unresolved method do not provide correct chemical and physical characteristics of the microparticles, since the results are the ensemble average of those for various microparticles with different sizes and properties. Therefore, a laser trapping/manipulation technique is an indispensable basis for analyzing various single microparticles undergoing vigorous Brownian motions in solution. Thus, the technique has been combined successfully with various analytical tools: steady-state and time-resolved absorption/fluorescence spectroscopies, Raman spectroscopy, and electrochemical techniques. In this review, the principles of laser trapping/manipulation and scanning laser micromanipulation techniques, including their instrumentation, are introduced. On the basis of such theoretical and experimental backgrounds, recent topics on single microparticle analyses are overviewed. In particular, the chemical and physical characteristics of single microparticles (ion-exchange resin beads, microdroplets, and so forth) in solution, revealed by laser trapping-microanalysis techniques, are described.
Keywords : laser trapping/manipulation; microspectroscopy; microelectrochemistry; single microparticles.
Akio Yuchi1
1 Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya-shi, Aichi 466-8555(Received 28 September 2005, Accepted 11 November 2005)
The performances of metal complexes and organometalic compounds containing polyvalent metal ions were studied as carriers of liquid membrane anion-selective electrodes from both fundamental and practical view points. 1) The high selectivities of simple dialkyltin(IV) compounds to phosphate and to a-hydroxycarboxylates were ascribed to formation of partially hydrolyzed polynuclear complexes, where these anions interacted with two Sn(IV) centers and were shielded from the solvent by alkyl groups projected from Sn(IV). This is the first evidence that the self-assembling reactions of a carrier and a sample anion create novel selectivities in potentiometry with liquid membrane anion-selective electrodes. 2) Tetraphenylporphine (H2tpp) complexes of Ti(IV), V(IV), Zr(IV), Hf(IV), Nb(V), and Ta(V) were prepared and evaluated as carriers of ISEs. Among a series of Zr(IV)-tetraphenylporphine complexes, cationic dimers, ([Zr2(OH)3(tpp)2],X), showed the selectivity characteristic of the ion-exchange process. The response was smaller for the cationic dimers containing X- of higher lipophilicities. In contrast, neutral monomers, [ZrX2(tpp)], showed the selectivity indicating contribution of ligand-exchange reactions. Among the neutral monomers, [ZrCl2(tpp)] was easily hydrolyzed to give [Zr(OH)Cl(tpp)], which showed an appreciable response to carboxylates. The response slowly deteriorated by replacement of chloride with hydroxide but was recovered in a reversible manner by conditioning the membrane with concentrated hydrochloric acid. The monomer, [Zr(OH)2(tpp)], was proposed as a carrier of an excellent citrate-selective electrode. 3) The neutral dimer [Nb2O3(tpp)2] rapidly reacted with phosgene to give [NbOCl(tpp)]. This reaction was successfully applied to the spectrophotometric monitoring of the spontaneous formation of phosgene in chlorinated hydrocarbons. 4) Potentiometric performances were briefly described about the Zr(IV)-dodecyliminodiacetate complex, the Ge(IV)-nitrilotriphenol complex, and naphthylboronic acid. All these results were discussed in terms of multi-points recognition, self-assembly, charges on carriers, additives, conditioning and life-time.
Keywords : ion-selective electrode; carrier; anion; citrate; two-phase reaction.
Junichi Sugiyama1, Hiroyuki Hanihara1, Kosuke Tanaka1, Akinori Igarashi1 and Masami Fujiwara1
1 Analytical Research Center, Research & Technology, LION corporation, 7-13-12, Hirai, Edogawa-ku, Tokyo 132-0035(Received 9 September 2005, Accepted 15 November 2005)
In previous paper, we established an accurate analyzing method by combining a size-exclusion chromatography (SEC) with multi-angle laser light scattering (MALLS) and a refractive index detector (RI) for determining the amount and absolute molecular weight of the cationic cellulose derivative {cellulose, 2-hydroxyethyl 2-[2-hydroxy-3-(trimethylammonio)propoxy]ethyl 2-hydroxy-3-(trimethylammonio)propylether,chloride} (CC), which is the most popular cationic polymer used in hair shampoo. However, an appropriate sample-preparation method for the analysis has not been established due to the lack of separation and dissolution procedures of the CC from the shampoo. In this work, we investigated a sample-preparation method in which the CC is efficiently separated from the shampoo without its molecular deterioration. We found that the CC is clearly solubilized by the SEC mobile phase (0.3 mol/l NaClO4 aqueous solution) as long as the CC is separated from the shampoo, because the tetrahydrofuran insoluble matter is immediately diluted by the mobile phase before drying out. In the SEC measurement, the CC from the model shampoo, the recovery rate and the reproducibility were sufficient. Moreover, no deterioration of the CC through the sample preparation was confirmed from a comparison between the molecular weight of the CC separated from the shampoo and that of the standard CC.
Keywords : extraction; preparation; cationic cellulose derivatives; determination molecular weight; polymer; shampoo; SEC; MALLS.
(Received 1 June 2005, Accepted 24 November 2005)
Silica gel particles impregnated with the ion associates of water-soluble p- sulfonatocalix[n]arene (n=6, H6L66-; n=8, H8L88-) ions and methyltrioctylammonium ion (MTA+), MTA-L6 and MTA-L8, were prepared, and their adsorption properties for some metal ions were examined. The adsorbents that were impregnated in the first place with the ion associates of metal complexes, such as UO22+ or Ti4+, then eluted these metal ions by dilute sulfuric acid, i.e., complex-type adsorbents, indicated large and selective adsorptivities for UO22+ and Ba2+. The supporting condition of the ion associates was also stable. No adsorptivity was observed for the adsorbents prepared by impregnating directly with the ion associates of these calixarenes with MTA+, i.e., the free ligand-type adsorbents. Also, the supporting condition of the ion associates was less stable than those of the complex types in the presence of metal ions. In the former, it was estimated that these calix[n]arenes are fixed in a “cone” structure in which their hydroxyl groups are ordered conveniently for taking specific metal ions. On the other hand, the latter were estimated to consist of “alternate” type calix[n]arenes in which some of the hydroxyl groups are located on opposing sides to make the reaction with metal ion impossible.
Keywords : p-sulfonatocalix[n]arene; methyltrioctylammonium ion; ion associate; metal adsorbent.
Shin-Ichi Ohira1, Md. Abul Kalam Azad2, Rika Kuraoka2, Takayoshi Tanaka1, Kotaro Mori2 and Kei Toda1
1 Department of Environmental Science, Faculty of Science, Kumamoto University, 2-39-1, Kurokami, Kumamoto-shi, Kumamoto 860-8555(Received 19 July 2005, Accepted 24 November 2005)
Flow analysis was applied to atmospheric analyses, and its usefulness and reliability were examined through a long-term measurement. The analysis system was comprised of small diffusion scrubbers and homemade fluorescence and conductivity detectors to measure H2S and SO2. The systems were settled in Kumamoto city and Mt. Aso, and the gases were monitored for two and a half years. We also brought this system to Aso crater, to walk around with, and investigated the gas distributions. Based on the gas data obtained at the two locations, the gas behaviors were investigated. The daily variations of SO2 and H2S were opposite, and the effects from the wind of the two gases were also different. The volcanic activity greatly affected the gas levels. In the active period, the SO2 gas level and the gas ratio of SO2/H2S became high. Near the fumaroles, the gas levels changed by 3 or 4 orders in a very short time. At 1 km downstream of the wind from the crater, the H2S ratio was much lower, which indicated that H2S decomposition occurred in a short time.
Keywords : diffusion scrubber; volcanic gas; sulfur dioxide; hydrogen sulfide; long-term flow analysis.
Mikio Ishikuro1, Yoshihiro Sato2, Kazuyuki Tohji2 and Kazuaki Wagatsuma1
1 Institute for Material Research, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai-shi, Miyagi 980-8577(Received 25 May 2005, Accepted 1 November 2005)
When carbon nanotubes (CNTs) are synthesized, some metal elements are usually employed as catalysts. The CNTs synthesized by this method are contaminated with metals and various forms of carbon and other impurities, which in some cases hinders the detailed characterization of such nanotubes and the assessment of their potential utility. Metallic elements (Fe, Cr, Mo, Al and Ni) in CNTs were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES). Several sample dissolution procedures were investigated. By using an acid dissolution procedure with a mixture of nitric acid and perchloric, or a fusion procedure with potassium hydrogensulfate, a part of the samples was adsorbed on the wall of a flask or a crucible. However, the CNTs could be completely dissolved after the procedures were repeated several times. When the CNTs were incinerated, a part of molybdenum was sublimated. By a microwave-assisted dissolution procedure, CNTs were completely dissolved with a mixture of nitric acid and perchloric acid. The analytical results of the CNTs obtained by ICP-OES had good reproducibility. The contents of metallic elements in CNTs were drastically reduced when they were purified by acids.
Keywords : carbon nanotubes; metal elements; microwave-assisted dissolution procedure; ICP-OES.
Susumu Shimoyama1, Hideo Matsui2 and Yasuko Shimoyama3
1 Kibi International University, 8, Iga-machi, Takahashi-shi, Okayama 716-8508(Received 8 September 2005, Accepted 1 November 2005)
Dayflower, knotgrass (indigo) and Prussian blue are known to be blue colorants used in traditional ukiyo-e color prints. For the non-destructive determination of the three blue colorants, the visible near-infrared reflection spectrum of each standard color sample was measured with a portable spectrophotometer using fiber optics. The three spectra, corresponding to each colorant, showed different patterns in the range of 630~900 nm, and the three colorants could be easily identified by each respective spectrum pattern. This analytical method was applied for the identification of blue colorant(s) used in 36 prints of “Thirty-six Views of Mt. Fuji”, the key-blocks of which were printed with blue color by Katsusika Hokusai, published in ca. 1830~33. It was identified that every key-block of the 36 prints was printed with indigo, which was hitherto assumed to be Prussian blue, while all color-blocks were printed with Prussian blue. This pattern of color usage, indigo for the key-block and Prussian blue for the color-blocks, was also observed in 5 prints of the “Shokoku Taki Meguri” series, the key-blocks of which were printed with blue color, by Katsusika Hokuai, published in ca. 1832~33.
Keywords : visible-near infrared reflection spectrum; non-destructive analysis; ukiyo-e print; blue colorant.
Hiroshi Tominaga1, Hiroko Kadobayashi1, Takako Yamaguchi1, Shinichiro Kamino1, Michiko Nishimura1 and Yoshikazu Fujita1
1 Osaka University of Pharmaceutical Sciences, 4-20-1, Nasahara, Takatsuki-shi, Osaka 569-1094(Received 8 August 2005, Accepted 21 November 2005)
We reported on a spectrophotometric determination of DNA binding protein, histone, with 3,4,5,6-tetrafluoro-2-carboxyphenylfluorone and manganese(II) in a previous paper. In the present work, preconcentration method for the determination of histone, which involves the filtration of a histone - 3,4,5,6-tetrafluoro-2-carboxyphenylfluorone - manganese(II) aggregate on a membrane filter, followed by its redissolution or tristimulus colorimetry, is described. Each of these methods is about 10-times more sensitive than the usual spectrophotometry.
Keywords : histone determination; 3,4,5,6-tetrafluoro-2-carboxyphenylfluorone; manganese(II); membrane filter.
Hideyuki Sakamoto1, Kazuko Yamamoto1, Toshihiro Shirasaki1 and Yoshinori Inoue2
1 Naka Application Center, Hitachi High-Technologies Corporation, 11-1, Ishikawa-cho, Hitachinaka-shi, Ibaraki 312-0057(Received 10 August 2005, Accepted 14 November 2005)
A pretreatment method of Al, Mn, Fe, Ni, Cu, Zn, Mo, Cd, Pb, and U in seawater has been investigated using the solid phase extraction column packed with polyamino-polycarboxylic acid type chelating resin. The dependence of pH on the recovery differed in each analytes. However, all analytes were simultaneously extracted at pH 5.5. Hence the optimum condition was decided at pH 5.5. Na, K, Ca, and Mg, which are major components in the seawater were not extracted at pH 7 and below. After the column was cleaned with 10 ml of pure water, the optimum concentration of nitric acid as eluate was 3 M. The analytes concentration in standard reference materials (Seawater NRC-CNRC, CASS-4) pretreated by the presented method was measured with the ion source mass spectrometer and the analytical values were well agreed with the certified values and the reference values without the interference of major components. Moreover, in the analysis of the analytes in the coastal sea water sample, a high recovery of 93~107% was obtained.
Keywords : polyamino-polycarboxylic acid type resin; matrix removal; seawater; solid phase extraction; heavy metal.
Hiroaki Matsuura
Riken Keiki. Co., Ltd., 2-7-6, Azusawa, Itabashi-ku, Tokyo 174-8744
(Awarded by University of Tsukuba dated March 25, 2005)
A novelf and highly sensitive electrochemical method has been developed for the determination of thiol compounds, based on the chemisorption/electrochemical desorption-procedure of the analyte on a metal electrode. The chemisorption (i.e. accumulation) of the analyte resulted in an enhanced sensitivity for an electrochemical measurement of the thiol compared to a direct determination of the same analyte without any accumulaion. Our thiol-sensing method was successfully applied to a highly sensitive measurement of an enzyme, acetylcholinesterase (AChE). Thiocholine, which was produced through the AChE-catalyzed reaction, was chemisorbed on a silver electrode, and was then electrochemically desorbed. The electrical charge that passed through the desorption process was proportional to the number of adsorbed thiocholine molecules, and hence to the AChE activity. The detection limit was 0.01 U l-1, which was one-hundred times lower than that obtained with a conventional amperometric method. Organophosphorus pesticides, diazinon (0.01~0.05 mg l-1) and ethylthiometon (0.01~0.2 mg l-1) could be measured by monitoring the activity change of AChE, based on the method mentioned above. We developed an enzyme immunoassay system for the determination of B-type natriuretric peptide (BNP). The detection limit was as low as 40 ng l-1. An automated system at an inexpensive BNP assay could soon be realized.
(Received September 22, 2005)
Keywords : thiol compound; chemisorption/electrochemical desorption-procedure; acetylcholinesterase activity; organophosphorus pesticides; electrochemical enzyme immunoassay.
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