Vol. 51 No. 5
May, 2002
Makoto Kurihara*, Takashi Hasebe** and Takuji Kawashima***
*Department of Chemistry, Faculty of Education, Shizuoka University, Shizuoka 422-8529
**Physical Chemistry, Analytical Research Laboratories, Eisai Co., Ltd., 5-1-3, Tokodai, Tsukuba-shi, Ibaraki 300-2635
***Laboratory of Analytical Chemistry, Department of Chemistry, University of Tsukuba, Tsukuba-shi, Ibaraki 305-8571
Chemiluminescence is a phenomenon of light emission during the course of a chemical reaction. The chemiluminescent method of analysis has received much attention due to its low detection limits and wide linear dynamic ranges, with relatively simple instrumentation. In recent years, further progress has been made in developing the chemiluminescent method for the quantitative analysis of inorganic, organic and biological substances. In order to increase the sensitivity of the CL method, micelles, reverse micelles and emulsions have been examined as solubilization media or intensity amplification agents. Since chemiluminescent detection is now one of the most sensitive detection methods in analytical chemistry, it is widely utilized in a variety of analytical methods, such as flow-injection analysis, high-performance liquid chromatography, capillary electrophoresis and immunoassay. Chemiluminescence biosensors combining substrate-specific enzyme reactions and chemiluminescence for biological substanses have also been extensively studied because they unite high selectivity and high sensitivity. This paper reviews the recent developments in the analytical applications of chemiluminescence.
Keywords : chemiluminescence; trace analysis; metal ions; biological substances; biosensor; analytical applications.
Yuzo Tamari*
*Faculty of Science and Engineering, Konan University, 8-9-1, Okamoto, Kobe 658-0072
(Received 9 October 2001, Accepted 21 February 2002)Considerably negative interference due to large amounts of iron and titanium in rocks was found when trying to determine trace selenium in sample solutions. However, the addition of EDTA and sodium fluoride mixture to the sample solution was significantly effective to mask the interfering ions derived from rocks. The present method is rapid and convenient: In a Teflon beaker, 0.1~0.5 g of rock with a mixture of 2 ml of hydrofluoric acid, 2 ml of nitric acid and 1.5 ml of perchloric acid was decomposed by heating on a hot-plate. The mixture transferred into a glass beaker with nitric and perchloric acid, where it was also decomposed until white fumes of perchloric acid appeared. After the reduction of selenate to selenite with 6 ml of 6 mol/l hydrochloric acid by boiling, 2 ml of a 0.1 mol/l EDTA-NaF mixture solution was added; this solution was diluted to 10 ml with water. The sample solution was measured by an atomic-absorption spectrophotometer equipped with a hydride generator. This method was applied to the determination of five Japanese rock reference samples of GSJ (Geological Survey of Japan). The analytical values of selenium by this method almost agree with those by fluorometry and with reference vales.
Keywords : selenium; rock; HG-AAS; masking with EDTA-NaF.
Norihisa Ishikawa, Yasushi Taniguchi and Hiroshi Matsushita*
*Department of Applied Chemistry, College of Engineering, Chubu University, 1200, Matsumoto-cho, Kasugai-shi, Aichi 487-8501
(Received 9 November 2001, Accepted 25 February 2002)An indirect potentiometric determination of metal ions using a chelate displacement reaction and a standard addition method, which does not require an adjustment of the ionic strength and the solvent composition of a sample of a water-organic solvent mixture, is proposed. A sample of the water-organic solvent mixture of volume V containing a metal ion M of concentration cx with an immersed N-selective electrode and a reference electrode is titrated with an aqueous solution (titrant-1) containing a metal-chelate (NL) of concentration c0. The electromotive forces (E1) corresponding to the added volumes (vf) of titrant-1 are measured, where the final added volume of titrant-1 is denoted by vf0. Subsequently, the same sample solution of a certain volume (V0) is added to the titrated sample; this solution is titrated again with an aqueous solution (titrant-2) containing NL of concentration c0 and M of concentration cM, and having the same ionic strength as that of titrant-1. The electromotive forces (E2) corresponding to the added volumes (vs) of titrant-2 are measured. If E1 and E2 corresponding to vf and vs that satisfy the condition vs=[1+(V0/V)]vf-vf0 are read off from two titration curves, and if a side-reaction coefficient considering the ion association of N in the solution of the E1 measurement is almost the same as that in the solution of the E2 measurement, 10ΔE/S=1+[cM/(cxV)](vf-vf0') concerning with cx is held, where ΔE=E2-E1, vf0'=vf0/[1+(V0/V)], and S is the response slope of the N-selective electrode. This cx is determined from the slope of linear plots of 10ΔE/S vs. (vf-vf0'). The present indirect method can be applied to determinations of the iron (III) and bismuth (III) in media of water-ethanol and water-1,4-dioxane mixtures with almost the same accuracy and precision as in aqueous solution by using CuIIedta and CuII-selective electrode, and by measuring at 50°C.
Keywords : indirect potentiometric determination; chelate displacement reaction; water-organic solvent mixture; linear plots.
Shanhu Bao and Toshiaki Nomura*
*Department of Chemistry, Faculty of Science, Shinshu University, 3-1-1, Asahi, Matsumoto-shi, Nagano 390-8621
(Received 25 December 2001, Accepted 4 March 2002)A twinned piezoelectric quartz crystal (PQC) was constructed with two of one electrode-separated PQCs, one of which oscillates separately. One of them was coated with a functional polymer film which could adsorb an analyte and the other with a polymer film having the same frequency behavior against the liquid properties, except for the adsorption of an analyte. Thus, the different frequency behaviors between the one electrode-separated PQCs result mainly from the adsorption of the analyte. On the other hand, the frequency behavior caused by the chitosan coating could be controlled with a coating of cellulose acetate on the other PQC. By controlling the experimental conditions, the twinned PQC selectively adsorbed copper(II), and the frequency change was proportional to the concentration. The adsorption of copper(II) onto chitosan, however, increased with the frequency. It was supposed that the adsorbed water on the chitosan with the hydrogen bond was removed by complexing with cupper(II), and then the frequency was increased because of decreasing mass on the chitosan.
Keywords : copper(II); piezoelectric quartz crystal(PQC); chitosan.
Shinji Itoh*, Hitoshi Yamaguchi*, Toshiyuki Hobo** and Takeshi Kobayashi*
*National Institute for Materials Science, Materials Engineering Laboratory, 1-2-1, Sengen, Tsukuba-shi, Ibaraki 305-0047
**Department of Applied Chemistry, Graduate School of Engineering, Tokyo Metropolitan University, 1-1, Minamioosawa, Hachioji-shi, Tokyo 192-0397
We examined sample pretreatment methods for analyzing copper (Cu) alloys using the glow discharge mass spectrometry (GDMS). By treating disk samples with five different methods, including dry-belt grinding with three types of abrasive cloth (alundum, corundum, and zirconia), specular grinding with alumina paste (1 µm), and etching with nitric acid, we obtained the relationship between the duration of the discharge and the ion beam ratio (IBR) of each element. After specular grinding and etching of pure Cu, ions of every element reached a steady value within a short time, and the IBR value was lower than in the other three methods. Copper-based alloys were similarly investigated. As a result, we found that, when etching with nitric acid, there were instances where the surface turned black, depending on the type of sample. In these cases, there were problems in that, although the IBR values of most of the alloy components showed reproducibility, no consistent results were obtainable for IBR values of C and O because of the abnormal values contained. Thus specular grinding was most suitable. We selected 12 mm for the sample masking diameter and 800 V-3 mA, as the discharge parameters while considering the analysis accuracy of the alloying elements. Seven types of standard reference materials were measured to obtain their relative sensitivity factors (RSFX. Cu). The analytical value of GDMS for the standard Cu alloy sample, i. e., MBH CRM CBC2, well matched the certified value or chemically analyzed value. Furthermore, the lower limit of determination for O was 0.5 mass ppm. The proposed method can be applied to the analysis of oxygen-free copper.
Keywords : sample preparation method; elemental analysis; copper-based alloys; relative sensitivity factor; glow discharge mass spectrometry.
Akira Tsuruta, Kazutoshi Kakita, Akihiro Ono and Mamoru Sakata*
*The Japan Society for Analytical Chemistry, 1-26-2, Nishigotanda, Shinagawa-ku, Tokyo 141-0031
(Received 2 November 2001, Accepted 26 February 2002)The Japan Society for Analytical Chemistry has prepared two new reference materials, JSAC 0401 brown forest soil (metal-spiked) and JSAC 0411 volcanic ash soil (non-spiked), for the analysis of trace metals. The materials were certified for the concentrations of 11 metals (Cd, Pb, Cr, Se, Be, Cu, Zn, Ni, Mn and V) in soil and those of several metals (Cd, Be, Cu, Zn, Ni and Mn for the brown forest soil and Mn for the volcanic ash soil) in water leachate as well. For certifying analytical data, an interlaboratory comparison exercise, in which 27 laboratories had participated, was carried out. The participants were requested to digest samples using alkali-fusion or acid digestion to determine the metal composition, and to leach the soil following the protocol issued by the Ministry of Environment, Japan. Various detection methods were employed to determine the metals. In a statistical analysis, the robust method using z-score was applied.
Keywords : forest soil; volcanic ash soil; certified reference materials; metals; the robust method; water leachate.
Takehiro Kojima, Kanako Yoshioka, Mika Ninomiya and Yasumasa Shigetomi*
*Department of Chemistry, Faculty of Science, Okayama University of Science, 1-1, Ridai-cho, Okayama-shi, Japan 700-0005
(Received 25 June 2001, Accepted 1 March 2002)Dyes in pickles were extracted from an ethanol solution by using a quaternary amine cartridge. The influence of the pH and the concentrations of ethanol and sodium chloride were examined. Tartrazine, Sunset Yellow, Acid Red, New Coccine and sorbic acid were separated from pickles by elution with an aqueous ammonia system. The dyes and sorbic acid were directly eluted from the cartridge with 3 % hydrochloric acid methanol solution and the eluate was analyzed by HPLC and TLC after neutralizing of the eluate. Recoveries of the dyes and sorbic acid ranged between 91.5 and 96.0 % with relative standard deviation of 2.8~4.5 %. Also, the detections were approximately 1.0, 2.0, 1.5, 2.0, and 0.2 µg cm-3 for Tartrazine, Sunset Yellow, Acid Red, New Coccine, and sorbic acid, respectively.
Keywords : tar dyes; solid phase extraction; quaternary amine cartridge; HPLC; TLC.
Akihito Kuno
Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1, Komaba, Meguro, Tokyo 153-8902
(Awarded by the University of Tokyo dated November 24, 2000)In this dissertation, nondestructive chemical speciation methods for solid environmental samples using Mössbauer spectroscopy and X-ray absorption fine structure (XAFS) were developed. Further, the behavior of heavy-metal elements in sediments collected from the Tama River estuary in Tokyo, Japan, was investigated by these methods. Prior to speciation, 33 elements in the estuarine sediments were determined by activation analyses. The iron speciation in the sediments was conducted by using Mössbauer spectroscopy in order to clarify the vertical distribution of the iron species. Although XAFS can be measured for many elements, unlike Mössbauer spectroscopy, the XAFS spectra of different species often severely overlap in the whole spectral region. For resolving the XAFS spectra of mixtures and to quantify the species therein, partial least-squares (PLS) and artificial neural networks (ANN) were employed. The overlapping spectra were successfully deconvoluted, and the relative abundances of the thus-determined iron species were consistent with the Mössbauer results. Since the availability of the multivariate calibration of XAFS was confirmed for Fe, it was extended to the speciation of Cr, Mn, and Zn. The Cr and Zn increased with depth in the forms of hydroxide and sulfide, respectively, while there was no significant variation in the chemical state of Mn.
(Received February 6, 2002)Keywords : nondestructive analysis; speciation; estuarine sediment; chemometrics; activation analysis; Mössbauer spectroscopy; X-ray absorption fine structure (XAFS).
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