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Volume 53, Issue 8
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Toshiyuki MITSUI, Shuji OKUYAMA, Minesada HIDA2004 Volume 53 Issue 8 Pages 773-791
Published: 2004
Released on J-STAGE: October 22, 2004
JOURNAL FREE ACCESSMultivariate analysis was applied to the determination of a mixed compound, and each component was accurately measured without a separation procedure. Two or more data from measuring one sample for analysis were used for a multivariable analysis. The qualitative analysis for identification is evaluated as follows. First, the principal component analysis is examined for removing the outlier samples. Next, the cluster analysis is examined for the formation of a cluster to unknown samples, or the determination of a belonging cluster of an unknown sample. Finally, the relations between the unknown samples are calculated by soft independent modeling of the class analogies method (SIMCA method) based on the result of the cluster analysis. The principal component analysis (PCS), the principal component regression analysis (PCR), and the different calculation method of regression analysis (DCR) were examined for quantitative analysis. When PCS or PCR were examined using two or more measured data, the accuracy of the determination improved as compared with the calibration-curve method. DCR was unnecessary for a calibration curve for the determination, and but was applied for a determining the content of each compound from samples in which three or more kinds of compounds had been mixed.
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Hideo HAYASHI, Masataka HIRAIDE2004 Volume 53 Issue 8 Pages 793-804
Published: 2004
Released on J-STAGE: October 22, 2004
JOURNAL FREE ACCESSInductively coupled plasma mass spectrometry (ICP-MS) offers a powerful multielement analytical method. Polyatomic interferences, however, are a major problem for the analysis of some elements. For example, 40Ar16O+, 40Ar35Cl+and 40Ar2+cause overlap interferences when detecting 56Fe+, 75As+and 80Se+, respectively. To address this issue, we studied low-pressure helium-ICP-MS, where a highly energetic helium plasma was generated with an rf power of 500 W in a water-cooled plasma torch. A sampling orifice was fabricated from an aluminum metal to minimize the background spectra. Different sample-introduction techniques were also developed for extending the scope of the proposed method. A liquid sample, for example, was first converted into tiny droplets with an ultrasonic nebulizer and then desolvated in a heater. The resulting dry aerosol was successfully introduced in the low-pressure helium plasma through a PTFE capillary tube. A small amount of sample was transported to the plasma after electrothermal vaporization on a tungsten filament. Other sampling techniques examined include hydride generation and laser ablation. The detection limits were measured based on 3σ for a large 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 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 different types of certified reference materials.
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Hiroshi OHRUI2004 Volume 53 Issue 8 Pages 805-815
Published: 2004
Released on J-STAGE: October 22, 2004
JOURNAL FREE ACCESSSince the discovery of enantiomerism by L. Pasteur in 1848, studies concerning to the discrimination of enantiomers have been among the important subjects in science. A recent finding that the relationship between the optical purity and the biological activity of biologically active compounds is very important, has stimulated the development of a highly potent chiral-discrimination method. The most widely used diastereomer method for the discrimination of enantiomers has a problem in that it is very difficult, or even impossible, to discriminate diastereomers having chiral centers separated by more than four bonds. The problem has been assumed to be intrinsic to the diastereomer method, and has been left unsolved. The author has proposed a solution to this problem by developing several fluorescent chiral labeling reagents.
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Research Paper
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Hidekazu MIYAHARA, Takayuki DOI, Youichi MIZUSAWA, Eiki HOTTA, Akitosh ...2004 Volume 53 Issue 8 Pages 817-825
Published: 2004
Released on J-STAGE: October 22, 2004
JOURNAL FREE ACCESSIn a new argon/helium compatible ICP torch designed to reduce plasma gas consumption, a cooling gas is exhausted in the same direction as the plasma, which causes concern about an immixture of both gases and air. In this study, the effect of a cooling gas difference and the flow rate on the emission properties of Ar and He ICP were investigated by measuring the emission intensities of OH, N2 and Ar. When an appropriate cooling gas and flow rate were chosen, the background emission caused by the air immixture was reduced.
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Yumi KATO, Yui ISHII, Ryohei WAKAO, Yoshikazu AMANO, Mikita ISHII, Mas ...2004 Volume 53 Issue 8 Pages 827-832
Published: 2004
Released on J-STAGE: October 22, 2004
JOURNAL FREE ACCESSA cyclic FIA system was designed for a determination of iodide ion with considering both environmental protection and a rapid, easy, economical and convenient operation. The proposed system consisted of the most simplified one line by popular colorimetric detection. A coloring switching system depending on the reaction temperature between iodine and starch was used for the proposed cyclic FIA. The present cyclic system by a 100 μl sample injection method under operating conditions of a 30°C to 60°C switching temperature and a reagent flow rate of 2.5 ml min−1 was available for 50 repeated runs with the 100 ml reagent solution. The calibration for the determination of iodide ion was linear between 1.0×10−5 M and 5.0×10−4 M in 100 μl sample injection. The reproducibility of the proposed method in a 100 μl sample injection was less than 1% in terms of relative standard deviation in 5 repeated runs with the 5.0×10−4 M iodide ion standard solution. The analytical time required was 30 s for one sample. The selectivity of the present method was good, and two Cr2O72− and SO42− anions giving the next larger absorbance signal to that of the iodide ion had a negligibly small interference in a (1 + 1) mixed solution of 5.0×10−4 M iodide ion standard with their foreign ions tested.
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Azusa YAMAMOTO, Kazuaki NAGAI, Tetsuo SAKAMOTO, Masanori OWARI, Yoshim ...2004 Volume 53 Issue 8 Pages 833-839
Published: 2004
Released on J-STAGE: October 22, 2004
JOURNAL FREE ACCESSAiming at the development of a rapid-analysis technique for environmental organic pollutants on suspended particulate matter (SPM) in air, a supercritical fluid extraction (SFE) technique was studied. The extraction efficiencies of typical organic pollutants spiked in alumina particles were first examined at various combinations of the extraction temperatures and pressures. The recovery of polyaromatic hydrocarbons (PAHs) showed strong dependence on both the extraction temperature and the pressure. This result was disscussed in terms of the enhanced solubilities and desorption/diffusion rates at a higher temperature and pressure. As for n-octadecane and tetrachlorobenzene, they showed little dependence on the fluid conditions. This implied that solubility has little effect on the recovery in case of these compounds with relatively high vapor pressures. The extraction behavior was also investigated using real SPM. Phthalates and Phenanthrene showed the maximum recovery at the highest temperature and pressure among three-step extraction, whereas n-alkanes and polysiloxanes were effectively extracted in the medium temperature and pressure step. The apparent difference in the extraction behavior implies the possibility of the selective extraction of the aimed analytes from real environmental samples.
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Shigeo TAKEMORI, Kouji YAMADA, Osamu ITOH, Nobuyoshi NANBU, Yoshifumi ...2004 Volume 53 Issue 8 Pages 841-845
Published: 2004
Released on J-STAGE: October 22, 2004
JOURNAL FREE ACCESSA chelating cellulose (SRY-Cell) containing thioglycollic acid as the chelating group was synthesized and studied for its sorption efficiencies with respect to Pb and Cu from an aqueous solution in both batch and column experiments. The influence of the pH on the adsorption, 250 μg each of Pb and Cu on SRY-Cell (0.1 g) from a 100 ml solution was studied in the pH range of 1.2∼10.8 by a batch process. Pb and Cu were quantitatively retained on the proposed adsorbent at pH>5. The effects of the flow rate of the sample solution through a column (polypropylene syringe, 78×16 mm i.d., 1.0 g of SRY-Cell was packed) were studied over the range of 10∼30 ml min−1. The retention of these metals on the SRY-Cell was not affected by the flow rate of the sample solution up to 30 ml min−1. Based on these results, the solution passed through the column at a flow rate of about 15 ml min−1. The extracted metals were stripped from the column using 20 ml of 1 M HCl at a flow rate of 5.0 ml min−1. The maximum sorption capacities were found to be 0.89 mmol g−1 and 0.64 mmol g−1 for Pb and Cu, respectively. The adsorbent was chemically stable and the adsorption-desorption cycles could be repeated at least 20 times. The method was applied to the concentration and determination of Pb and Cu in solar salt and water samples.
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Technical Paper
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Minemasa HIDA, Motoyasu SATOH, Toshiyuki MITSUI2004 Volume 53 Issue 8 Pages 847-850
Published: 2004
Released on J-STAGE: October 22, 2004
JOURNAL FREE ACCESSA method has been examined that analyzes whether or not a very small amount of the stimulant methamphetamine hydrochloric acid salt (MA) in dimethylamphetamine hydrochloric acid salt (DMA), which is a stimulant material, exists. The optimization of an extraction system for MA was carried out as a pretreatment process of GC-MS. This method was able to detect 5 μg of MA in 100 mg of DMA as a result. DMA powder was easily recovered by air-drying to remove the extraction solvent.
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Akio SAKURAGAWA, Miki NAKANE2004 Volume 53 Issue 8 Pages 851-856
Published: 2004
Released on J-STAGE: October 22, 2004
JOURNAL FREE ACCESSFrom the viewpoint of a graphite carbon column with excellent durability, it was applied to the ion chromatography of several organic acids. The carbon column was permanently coated with the cetylmethylammonium ion, and the elution behaviors of several organic acids and inorganic anions (acetic acid, lactic acid, succinic acid, malic acid, tartaric acid, citric acid, Cl−, NO2−, NO3−) were examined according to an ion chromatography that combined conductometric detection using a mobile phase of the salicylic acid system, when an ion-exchange ability was given to the graphite carbon column. Though the peaks overlapped among Cl−, NO2− and malic acid, it was possible that 9 components were separated within 15 minutes. The calibration curve of each ion was over 0.999 with the correlation coefficient (r2), and the relative standard deviations (RSD) by repeated measurements were found tobe 0.53∼1.03% (n = 6) with good reproducibilities. Analytical results for organic acids, that were contained in food vinegar, were examined using the proposed method. It was possible to get within 1.0% and good values were obtained that comparied with a reversed phase-high performance liquid chromatography (HPLC) using ODS column.
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Analytical Report
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Hideaki KITAMI, Tetsuo WATANABE, Takio KITAHARA, Yoshimi ISHIHARA, Jir ...2004 Volume 53 Issue 8 Pages 857-861
Published: 2004
Released on J-STAGE: October 22, 2004
JOURNAL FREE ACCESSA cartridge-type solid-phase extraction method for the determination of anionic surfactants, followed by high-performance liquid chromatography with ultraviolet detector (HPLC-UV) is described. The HPLC-UV measurement method provides good linearity of the calibration curve as well as repeatability. The correlation coefficients of the calibration curve were estimated to be from 0.9989 to 0.9996 for anionic surfactants in the concentration range from 0.1 mg l−1 to 10 mg l−1. For anionic surfactants by HPLC-UV, the detection limits were calculated to be 0.031 mg l−1 for ABS analysis and 0.047 mg l−1 for synthetic detergent test for laundering, at which the signal-to-noise (S/N) ratio was 3. Methanol was recommended for the elution of anionic surfactants from the cartridge-type solid-phase. The recoveries for anionic surfactants for ABS analysis from distilled water spiked at concentration of 1.0 ng ml−1 was 93.2%, and the relative standard deviations (RSD) was 6.3% by a cartridge-type solid-phase extraction method. This measurement method could be successfully applied to the determination of anionic surfactants in tap water.
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