Vol. 4 9, No. 1 1
November, 2000
Kousaburo Ohashi, Sung-Yong Choi and Jin Ougiyanagi*
*Department of Environmental Sciences, Faculty of Science, Ibaraki University, 2-1-1, Bunkyo, Mito-shi, Ibaraki 310-8521
(Received 29 May 2000)8-Quinolinol and various substituted 8-quinolinols have been extensively investigated from the viewpoint of analytical chemistry. It is essential to enhance the selectivity of their individual metal ions in practical samples, such as alloys, environmental samples, biological samples. Since the analytes of interest are often accompanied by diverse substances or a large amount of matrices, the analytes have been required to be separated and pre-concentrated prior to their determination by various instrumental analyses. This review presents an overview and a discussion of the characteristics of the acid-base equilibria, metal complex formation and liquid-liquid distribution equilibria of 8-quinolinol derivatives (HA), the extraction equilibrium of metal ions with HA, the kinetics of the metal extraction with HA, the separation and pre-concentration of metal ions by using liquid-liquid extraction, and complex-forming adsorbents such as chelating resin, reagent-immobilized or -loaded silica, chitosan, and activated carbon.
Keywords : 8-quinolinol and its derivatives; pre-concentration and separation; determination of traces of metal ions; solvent extraction; equilibrium and kinetics.
Tetsuya Kawashima*, Toshihiko Sugimoto** and Toshio Ogawa***
*Kameyama branch, Nitto Analytical Techno Center Co., LTD., 919, Fuke, Kameyama-shi, Mie 519-0193
**Product Development Dept., Printed Circuit Div., Electric·Electronic Business Sector Nitto Denko Co., LTD., 919, Fuke, Kameyama-shi, Mie 519-0193
***Laboratory for Material Design Engineering, Kanazawa Institute of Technology, 7-1, Ohgigaoka, Nonoichi-machi, Ishikawa 921-8501
The mechanism of the deterioration process of an adhesive composed of nitrile rubber(NBR) and epoxy resin is discussed based on the techniques of differential scanning calorimetry (DSC), transmission electron microscope (TEM), FT-IR and GC. An accelerated test of the adhesive was carried out at 120°Cand 100% relative humidity. It was found that the deterioration of the adhesive was mainly due to degradation of the NBR domain. The glass transition temperature of the adhesive became lower and the staining ability of OsO4 for the NBR decreased with time. The degradation of the NBR was accelerated by decrease in the antioxidant content during curing step of the adhesive.
Keywords : transmission electron microscope; FT-IR; adhesive; nitrile rubber; deterioration.
Haruhiko Tajima, Kazunari Tsujimura* and Masatoshi Yamaguchi**
*Chemicals Evaluation and Research Institute, Kurume Laboratory, 19-14, Chuoh-machi, Kurume-shi, Fukuoka 830-0023
**Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1, Nanakuma, Johnan-ku, Fukuoka 814-0180
A sensitive method for the determination of 17β-estradiol,estrone and estriol in river water has been developed, based on SPE cartridge extraction and HPLC coupled with negative electron ion spray tandem mass spectrometry(LC/MS/MS) in the multiple reaction monitoring mode(MRM). An internal standard calibration method using a stable isotopic labeled 17β-estradiol was employed for quantitation. The limit of detection(LOD) for these estrogens in river water was 0.3 ng/l. Good linearities of the calibration curve were obtained in the concentration range from 0.4 ng/l to 80 ng/l. The correlation coefficients were >0.995 for all estrogens. The recoveries of these estrogens were 65.9~96.9%. The relative standard deviations were 5.8~11.1% for 0.4 ng/l, 8.1~11.8% for 0.8 ng/l, 4.2~12.6 ng/l for 1.6 ng/l. Using this method, the behavior and occurrence of estrogens in river water and the effluent of sewage treatment plants were investigated in Chikugo-river(Kyusyu, Japan). A few estrogens were detected in the river water by LC/MS/MS, and the levels were ND-0.6 ng/l. However, in all samples of sewage-treatment plants, 17β-estradiol and estrone were detected, and the levels were 0.5~4.2 ng/l(17β-estradiol) and 5.3~35.1 ng/l(estrone). On the other hand, 17β-estradiol was detected in most samples, including river water, by ELISA(17/18); the levels in sewage-treatment plants were 6.0~13.5 times higher than those by LC/MS/MS. The differences in these results might be due to the cross reaction of ELISA.
Keywords : 17β-estradiol; estrone; estriol; estrogen; river water; sewage treatment plant; LC/MS/MS; ELISA.
Hideyuki Matsuta, Kazuaki Wagatsuma* and Kuniyuki Kitagawa**
*Institute for Materials Research, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai 980-8577
**Research Center for Advanced Energy Conversion, Nagoya University, Furo-Cho, Chikusa-ku, Nagoya 464-8603
In order to improve the precision of depth profiling in glow-discharge optical emission spectrometry, sampling from the sample electrode with laser ablation and excitation of the sample atoms with an r.f. helium glow plasma have been attempted for a glow- discharge emission source. Consequently, it has been found that sample atoms can be introduced into the glow plasma by laser ablation, and excitation of the atoms with the r.f. helium glow plasma is possible during a period of between 100 µs and 7 ms after the irradiation of a Q-switched Nd:YAG laser. Since the r.f. helium glow plasma has little sputtering ability, the sampling and the excitation processes can be controlled independently; thus, the above-mentioned procedure would improve the precision of depth profiling in glow-discharge optical emission spectrometry. In addition, an enhancement of the emission intensity and the production of metastable helium atoms were observed by using a bias-current conducting method described in our previous paper. These effects could also improve the sensitivity in glow-discharge optical emission spectrometry.
Keywords : glow discharge optical emission spectrometry; laser ablation; helium; glow discharge plasma; radio frequency.
Toshihiro Yamada, Masaharu Tanaka, Satoshi Hirano, Yasuhiro Nagao, Kazuhiro Kobayashi, Takanobu Sakurai, Youko Furukawa and Youichi Nobuhara*
*Central Research Institute, Nissin Food Products Co., Ltd., 2247, Noji, Kusatsu-shi, Shiga 525-0055
(Receiverd 26 June 2000, Accepted 23 August 2000)We examined a quantitative analysis of a styrene oligomer 6 specimen in instant noodles contained in a polystyrene container. Therefore, we made six kinds of poly-deuterated styrene oligomers (surrogate) which coped in it from the viewpoint of chemosynthesis. Furthermore, we established a high-precision analytical procedure in an alimentary form of instant noodle in which the impurity which contains a noodle, an ingredient material, soup by combining extraction and purification is abundant in. This made an accretion recovery of surrogate that more than 80% can be secured indicator. It was confirmed in 17 kinds of instant noodles in PS containers that it had an accurate elusion amount of the styrene oligomers in the alimentary form which used a surrogate body represented by three kinds of PS material. Further, as for the instant noodles with a PS container as well which administered the decrease countermeasure of the styrene oligomer elusion amount, it was confirmed.
Keywords : polystyrene container; determination; surrogates; synthesis; styrene oligomers.
Akitoshi Okino, Daigo Kaneko*, Hironobu Yabuta and Eiki Hotta**
*Department of Electrical & Electronic Engineering, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552
**Department of Energy Sciences, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502
To overcome some problems imvolving the argon ICP-MS, helium ICP-MS device was developed using an enhanced vortex flow torch. Because a secondary discharge in the interface region is the main problem for practical use, we constructed a new vessel for measuring the discharge. The basic characteristics of the plasma in the interface region were measured by a Langmuir probe method. The electron temperature (Te) and the electron number density (ne) values at an RF input power of 700 W were 2.7 eV and 3.7 × 105 cm-3, respectively, for a position 6 mm from the sampler orifice. The Te values were higher, but the ne values were much lower than those of Ar ICP-MS. The probe measurements also indicated that the Mach disk position in this device was about 8 mm from the sampler orifice.
Keywords : ICP-MS; helium ICP; Langmuir probe; Mach disk.
Shogo Suzuki, Yukiko Okada and Shoji Hirai*
*Faculty of Engineering, Musashi Institute of Technology, 971, Ohzenji, Asao-ku, Kawasaki 215-0013
(Received 3 August 2000, Accepted 8 September 2000)When γ-rays are counted using γ-ray spectrometry for neutron activation analysis (NAA), the Compton continum from high-energy γ-rays often interfers with the detection of nuclides with lower energy γ-rays. A coincidence counting of γ-rays in the cascade series with a coaxial Ge detector and a well-type NaI(Tl) detector can reduce this problem. The coincidence counting method was applied to the determination of Se, Hf, Ba, Cs, Co, Sb and Sc in 3 kinds of certified reference materials (NIES CRM No.16 river sediment, NIES/NIRS typical Japanese diet CRM and NIES/WAMRL fish otolith CRM) and 10 kind of iron remains excavated at the ruins of Kaman-Kalehoyuk in Turkey. These samples and comparative standards were irradiated for 6 h at a thermal neutron flux of 3.7 × 1012 n cm-2 s-1 in the Rikkyo University Research Reactor (TRIGA Mark-II, 100 kW). The irradiated samples were couted by multiparameter MCA (LN-9000, Laboratory Equipment Corporation). A coaxial Ge detector (relative efficiency of 21% and FWHM of 1.8 keV at 1332 keV) was used for the conventional counting method. For the coincidence counting method, the coaxial Ge detector along with a well-type NaI(Tl) detector (6 in.φ × 6 in., well 3 in.φ × 4 in.) was used. Using this method to determine Se, Hf, Ba, Cs, Co, Sb and Sc, the lower limit of the determination was improved by 2~4 times compared with the conventional counting method using the coaxial Ge detector. The determined values were in good agreement with the certified values.
Keywords : coincidence counting method; neutron activation analysis; certified reference material; iron remain; multiparameter MCA.
Yoshikazu Nakamoto*
*Tokuyama Refinery Idemitsu Kosan Co., Ltd., 1-1, Singu-cho, Tokuyama-shi, Yamaguchi 745-0843
(Received 7 June 2000, Accepted 2 August 2000)Because organic chlorine in petrochemical products influences their stability, it is important to determine trace organic chlorine in them. An aluminium,strontium, and cobalt nitrate mixture was used as a matrix modifier. A simple and rapid method was established for the determination of organic chlorine in products by using aluminium monochloride molecular-absorption spectrometry. The detection limit and relative standard deviation for 100 ng g-1 chorine determination were 10 ng g-1 and 4.1%, respectively. The results obtained from the proposed method were in agreement with those obtained from a chlorine analyzer.
Keywords : organic chlorine; matrix modifier; aluminium, strontium, cobalt nitrate; aluminium monochlorine molecular absorption spectrometry; petrochemical products.
Norikazu Nagae and Toshiyuki Enami*
*Nomura Chemical Co., Ltd., 851, Anada-cho, Seto-shi, Aichi 489-0003
(Received 29 June 2000, Accepted 9 August 2000)The retention behavior of the reversed-phase was evaluated under 100% aqueous conditions. It is commonly said that reversed-phases, such as ODS (C18) and C8, show a decrease in the retention time under 100% aqueous conditions. The mechanism of the decrease in retention was found to be that the 100% aqueous mobile phase was pulled out of the pore of the packing materials, so that the stationary phase in contact with the mobile phase decreased. Some parameters, such as the pore size, length of the alkyl group of the stationary phase, temperature and buffer in the mobile phase, were shown to influence the decrease in retention. The C30 phase didn't show any decrease of retention. Furthermore, ODS, which had a larger pore, didn't show any decrease in the retention time, but showed high reproducibility in retention. In contrast, TMS (C1), which had a smaller pore, showed a decrease of retention, although it was known that TMS, which had 10 nm of a pore, didn't show a decrease in retention. The reversed-phase could be used under 100% aqueous conditions, and showed high reproducibility in retention when it was filled with some terms.
Keywords : reversed-phase; 100% aqueous mobile phase; retention behavior; HPLC.
Tomokazu Tsuchiya and Takaharu Honjo*
*Department of Chemistry, Faculty of Science, Kanazawa University Kakuma-machi, Kanazawa-shi, Ishikawa 920-1192
(Received 5 June 2000, Accepted 7 August 2000)A new method for the separation of lanthanum(III) and barium(II) as their thenoyltrifluoroacetone(TTA) complexes with dibenzo-18-crown-6(DB18C6) in o-dichlorobenzene has been established by means of synergistic extraction and back-extraction combined with inductively coupled plasma atomic emisson spectrometry(ICP-AES). When the mixtures of La(III) and Ba(II) were extracted for 5 min at pH 4.5, only lanthanum(III) was extracted quantitatively, whereas barium(II) remained in the aqueous phase. After the phases were separated, barium(II) was extracted quantitatively for 5 min at pH 7.9 again. Then, the two phases were each shaken with 0.1 M HCl in order to back-extract lanthanum(III) and barium(II) from the organic phases; both metal ions were determined by ICP-AES. In the process, lanthanum(III) and barium(II) TTA chelates in o-dichlorobenzene formed stable adducts with DB18C6 (La(TTA)3·nDB18C6 and Ba(TTA)2·nDB18C6, n=0-2). The stability constants(βn) of the adducts determined by means of curve-fitting method were log β1=3.7 and log β2=5.9 for lanthanum(III), and log β1=3.8 and log β2=7.9 for barium(II). The extraction constant(log K) of lanthanum(III) adduct was -3.7.
Keywords : lanthanum(III); barium(II); thenoyltrifluoroacetone; dibenzo-18-crown-6; synergistic separation extraction.
Yuji Suzuki*
*Saitama Prefectural University Junior College, 820, Sannomiya, Koshigaya-shi, Saitama 343-8540
(Received 7 August 2000, Accepted 7 September 2000)The chemical characteristics of ditaurobilirubin, which is a synthesized conjugated bilirubin, have been investigated. The absorption maximum, spectrum and absorption intensity of this substance changed in the presence of methanol, Triton X-100, human albumin or serum protein, and its absorbance at the absorption peak increased by the addition of methanol and protein. Also, these four substances promoted the photochemical reaction of ditaurobilirubin. Its change to other substances by the irradiation of light was several times faster than unconjugated bilirubin, but in this reaction biliverdin almost did not formed. However, even at 4°C in the dark ditaurobilirubin spontaneously changed to biliverdin for a short term, unlike unconjugated bilirubin. In the diazo coupling reaction, a colored product readily formed, but its stability was low. The absorption maximum of the colored product was close to that formed from the serum direct bilirubin when the reaction was performed in the presence of human albumin, serum protein or Triton X-100.
Keywords : ditaurobilirubin; stability; photoreaction; diazo coupling reaction.
Yuetsu Danzaki, Hideyuki Konno, Tetsuya Ashino, Kouichi Tozawa and Masakuni Takeuchi*
*Institute for Materials Research, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai 980-8577
(Received 4 July 2000, Accepted 11 September 2000)Elemental analysis of oxide superconductors yields useful information about their properties. As an analytical method, inductively coupled plasma-optical emission spectrometry (ICP-OES) is more convenient than spectrophotometry or titrimetry. However, various analytical errors are sometimes included in the procedure of ICP-OES, especially because of spectral and non-spectral interferences. To minimize these errors, the solutions used for calibration curves are ideally prepared by matrix matching with the sample solution. However, it is difficult to obtain the calibrational relation unless standard reagents containing no impurities are obtained, and unless binary alloy samples are analyzed. In this work, instead of a matrix-matching method, a sequential correction method is suggested, where several error factors, such as fluctuation of the emission intensities, spectral interferences, non-spectral interferences and blank values, are individually corrected on the basis of calibration curves prepared with single-element solutions. By using the sequential correction method, we have investigated an ICP-OES total analysis for bismuth-system oxide superconductors.
Keywords : bismuth-system oxide superconductors; ICP-OES; sequential correction method; spectral interferences; non-spectral interferences.
Department of Medical Test, College of Medicine, University of Beihua, No.1, Beijin road, Jilin city, 132001, Jilin province, China
(Awarded by University of Tokyo dated March 26, 1999)This dissertation gives a brief description of two new approachs for the assay of sulfated bile acid (SBA) in urine based on flow-injection chemiluminescence and spectrophotometry with immobilized enzyme reactors. The analytical procedure of FIA-chemiluminescence is as follows.
SBAs take place in the reaction of desulphation under a catalytical action of a bile salt sulfatase immobilized in the column and formed 3β-hydroxyl bile acids; the formed 3β-hydroxyl bile acids react with nicotinamide adenine dinucleotide (β-NAD+) under the catalysis of 3β-hydroxysteroid dehydrogenase coimmobilized in the same column, and are converted to 3-ketosteroid. At the same time, β-NAD+ is changed into reduced nicotinamide adenine dinucleotide (NADH). Looking like a chain reaction, 1-MPMS is taken as an electron mediator and reacts immediately with NADH coexisting in the carrier solution, and is turned into 1-MPMSH2; the formed 1-MPMSH2 again reacts with dissolved oxygen existing in the carrier solution, and produces hydrogen peroxide. Last, the hydrogen peroxide reacts with the luminol reagent, and gives out light in the presence of POD. SBA can be determined by the luminous intensity. Based on this principle, an approach was established for the determination of SBAs. Its sampling frequency is 30 sample/h, and the relative standard deviation (RSD) is smaller than 2.2%. It can be used to determine SBAs in the range of 0.1~12 µM. Flow-injection spectrophotometry with immobilized enzyme reactors is based on a part of the principle mentioned above, namely, after β-NAD+ is converted to NADH, by catalysis of diaphorase immobilized, NADH reacts with a novel colouring reagent, called Water Soluble Tetrazolium Blue (WST-5), to generate a blue diformazan dye. Last, SBA is determined from the absorbance of the formed formazan (λmax= 550 nm). By using the manifold and optimized conditions, the author has obtained the linear response in the range of 1~75 µM GLCA-S with a correlation coefficient of 0.999 and an analytical rate of 15 sample/h. RSD was less than 1%. The recoveries (91~108%) of GLCA-S added into urine were satisfactory and the assay had a good correlativity with manual the UBASTEC method. As a consequence, based on the method, a new-type of analytical instrument for the assay of SBAs in urine has been developed. The author also thinks that this method is very useful for routine analyses in a clinic laboratory and long-period monitoring to patients with acute hepatitis, liver cirrhosis, and intra- and extra-hepatic biliary obstruction urinary.
(Received August 24, 2000)Keywords : flow-injection analysis; sulfated bile acid; chemiluminescence; immobilized enzyme; spectrophotometry.
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