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Volume 66, Issue 9
Displaying 1-9 of 9 articles from this issue
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Annual Topic “photo” : Research Papers
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Yuhei YAMAMOTO, Azusa TAGAMI, Toshihiro SHIRASAKI, Akira YONETANI, Tak ...Article type: Annual Topic “photo” : Research Papers
2017 Volume 66 Issue 9 Pages 629-637
Published: September 05, 2017
Released on J-STAGE: October 05, 2017
JOURNAL FREE ACCESSAn investigation of the atomization mechanism of boron using a commercially averable graphite furnace atomization absorbance spectrometer (GFAAS) was difficult due to the upper limit of atomization temperature. By customizing the GFAAS equipment, the atomic absorbance of boron was observed in a graphite furnace under a constant heating rate, and could be applied to a kinetic approach using the Sturgeon method. In the case of a Fe matrix modifier, which can improve the limit of detection of boron using GFAAS, the pyrolysis curve showed a curve with two plateaus, suggesting the presence of stable products during the pyrolysis step. At the first step (< 1260 K), the activation energy (Ea) of the boron species was 799±72 kJ mol−1, whereas at the second step (1400–1740 K) Ea was 485±78 kJ mol−1. The former Ea value was similar with that of Ca modifier, the latter Ea value was identical to that of Cu mofidier. The boron atomization processes was estimated using model reactions and their reaction enthalpy. At the first step, the decomposition of boron oxides was the rate-determining step, whereas at the second step the oxidative decomposition of boron carbides was the rate-determining step.View full abstractDownload PDF (999K)
Annual Topic “photo” : Notes
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Asami YAMAMOTO, Kenta ADACHIArticle type: Annual Topic “photo” : Notes
2017 Volume 66 Issue 9 Pages 639-646
Published: September 05, 2017
Released on J-STAGE: October 05, 2017
JOURNAL FREE ACCESSDue to the biological importance of α-amino acids and their derivatives, the development of novel colorimetric probes for these molecules has been an active research area in recent years. In this study, surface-enhanced photochromic phenomena by various α-amino acids (L-aspartic acid [Asp], L-leucine [Leu], and L-lysine [Lys]) adsorbed on molybdenum(VI) oxide (MoO3) nanoparticles in an aqueous system were investigated by means of UV-vis absorption spectrometry. No derivatization of α-amino acids is required, and eventually highly accurate determinations are obtained from the UV-induced MoO3 photochromic coloration. Under optimal conditions in this system, limit of quantitation (LOQ) values of 3.45 × 10−6, 2.08 × 10−6, and 1.53 × 10−6 mol dm−3 for Asp, Leu, and Lys, respectively, were achieved at pH 2. During UV irradiation, the detection process could be visually observed by naked eyes. A simple and unique approach to explore sensitive "label-free" colorimetric sensing toward α-amino acids is proposed.View full abstractDownload PDF (951K)
Notes
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Takumi YOMOGIDA, Shiho ASAI, Morihisa SAEKI, Yukiko HANZAWA, Takuma HO ...Article type: Notes
2017 Volume 66 Issue 9 Pages 647-652
Published: September 05, 2017
Released on J-STAGE: October 05, 2017
JOURNAL FREE ACCESSPalladium-107 can be found in high-level radioactive liquid wastes (HLLW). Owing to its long half-life (6.5 million years), determining the 107Pd contents in HLLW is essential to evaluate the long-term safety of HLLW repositories. However, the 107Pd contents in HLLW have not been reported because of difficulties in a pretreatment for the measurement. Treating highly radioactive samples, such as HLLW, may cause radioactive contamination and radiation exposure to workers. Therefore, a simple and non-contact separation procedure is desirable. In this study, we applied a simple and non-contact separation technique based on laser-induced photoreduction to a simulated HLLW solution. The solution, which consisted of 14 major elements (Rb, Sr, Zr, Mo, Ru, Rh, Pd, Cs, Ba, La, Ce, Pr, Nd, Sm) in a 3 mol L−1 HNO3 solution, was used to evaluate the separation performance. The results showed that the recovery of Pd from a simulated HLLW solution depended on the solvent, concentration of ethanol, concentrations of Pd ion, irradiation time and pulse energy. The results indicate that the coexisting elements in a sample hampered the photoreduction of Pd ions or the formation of a Pd precipitate and the loss of a Pd precipitate at centrifugation caused a decrease of the Pd recovery. By considering the conditions at laser irradiation, the results showed that the Pd recovery reached 59 %, while about 99 % of the other 13 elements was removed. This indicates that the non-contact and high-selective separation of Pd is achievable with the proposed separation technique under a suitable separation condition.View full abstractDownload PDF (928K)
Analytical Reports
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Yuto ONETA, Masayuki YAUCHI, Akiko HOKURAArticle type: Analytical Reports
2017 Volume 66 Issue 9 Pages 653-662
Published: September 05, 2017
Released on J-STAGE: October 05, 2017
JOURNAL FREE ACCESSIt has been recently reported that unscrupulous producers have been mislabeling geographic origins of their food products. The development of techniques to scientifically determine geographic origins of agricultural products has been requested so as to guarantee consumers' food safety. Dietary salts are mainly produced from sea water, rock salt, and agglomerate from salt lake; consequently, their prices can greatly vary depending on the production processes and the sources. Because the chemical composition of salts should be reflected by their sources and the making processes, we have tried to determine trace elements by using a highly sensitive XRF instrument, and demonstrate so as to identify the characteristics of dietary salts. By optimizing the XRF measurement conditions, the intensities of 15 elements (Na, Al, Cl, K, Ca, Cr, Mn, Fe, Cu, Zn, As, Br, Rb, Sr, I) in dietary salts were rapidly and nondestructively obtained. Principal-component analyses using the normalized intensities of eight elements (K, Ca, Mn, Fe, Br, Rb, Sr, I) were performed to distinguish the characteristics of salt production and its source. We successfully demonstrated our ability to determine trace elements in dietary salts by XRF analysis with simple and quick sample preparation. It is beneficial to discriminate the characteristic of salts.View full abstractDownload PDF (2162K)
Accounts
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Shin-ichi MIYASHITA, Shin-ichiro FUJII, Kazumi INAGAKIArticle type: Accounts
2017 Volume 66 Issue 9 Pages 663-676
Published: September 05, 2017
Released on J-STAGE: October 05, 2017
JOURNAL FREE ACCESSICP-MS-based analytical techniques for nanoparticles and cells, such as single-particle ICP-MS (spICP-MS) and single-cell ICP-MS (scICP-MS), are currently under the spotlight as promising techniques. In contrast to a conventional ICP-MS measurement, they require highly time-resolved measurements to individually analyze particles and cells, and processing of huge amounts of measurement data. Furthermore, these techniques require highly efficient and repeatable sample introduction to perform high-throughput and highly precise analysis. To date, the authors have developed a system that enables to concurrently carry out highly time-resolved measurements, which results from direct reading of the ion pulse current from the ICP-MS detector, and the processing of measurement data. Moreover, the authors have developed a unique high-efficiency sample introduction system that enables to significantly reduce sample loss during the sample introduction process. This paper provides development outlines of the systems and their beneficial applications to spICP-MS and scICP-MS.View full abstractDownload PDF (990K) -
Analytical Evaluation of Bioactive Small Peptides on Their Intestinal Absorption and BioavailabilityMitsuru TANAKAArticle type: Accounts
2017 Volume 66 Issue 9 Pages 677-685
Published: September 05, 2017
Released on J-STAGE: October 05, 2017
JOURNAL FREE ACCESSSmall peptides with di- or tripeptide length have been known as bioactive food components to prevent lifestyle-related diseases (e.g. hypertenstion). Although they must be absorbed into the blood circulation or accumulated in targeted tissues after their intake, the bioavailability was still uncertain due to limitations of analytical methods. Thus, the aim of this study was to develop analytical methods to measure these small peptides based on mass spectrometry (MS) techniques. In this study, a 2,4,6-trinitrobenzenesulfonate-derivatized liquid chromatography–multiple reaction monitoring–tandem mass spectrometry (LC-MRM-MS/MS) technique was developed to significantly enhance the sensitivity of small amines including peptides. The evidence of phytic acid to improve poor detection of small peptides (< 500 Da) by matrix-assisted laser desorption/ionization-imaging mass spectrometry (MALDI-IMS) was also demonstrated. Here, this review article summarizes these developed MS techniques as well as the resulting bioabailability and intestinal absorption behavior of these bioactive small peptides based on the established analytical methods.View full abstractDownload PDF (1133K)
Research Papers
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Yuya HASEGAWA, Yasutada SUZUKI, Susumu KAWAKUBOArticle type: Research Papers
2017 Volume 66 Issue 9 Pages 687-692
Published: September 05, 2017
Released on J-STAGE: October 05, 2017
JOURNAL FREE ACCESSA sensitive on-site determination method for phosphorus was developed by collecting phosphorus as phosphoric acid ion in Molybdenum Blue (MB) on a mixed cellulose ester membrane filter with a pore size of 0.45 μm and by measuring reflection absorbance (RA) of MB on the filter using a laboratory-made palm-top size reflectometer with a red light-emitting diode (630 nm). The formation of MB was completed within 10 min at 10 - 40 °C in the presence of Bi(III) as an accelerator. The collection of MB was carried out by adding tetradecyldimethylbenzylammonium chloride as a coagulator. A portable drier was used for on-site drying of the filter. The value of RA was proportional to the amount of phosphorus up to 0.1 μg. The detection limit was 0.003 μg (0.001 μg mL−1). The interference of As(V) forming MB was eliminated by the reduction of As(V) to As(III) with sodium thiosulfate. Arsenic(V) was tolerable up to 0.4 μg. The proposed method was successfully applied to river-, spring-, and top-water samples containing 0.001 μg P mL−1 levels. The analytical time was 20 min for one sample.View full abstractDownload PDF (712K)
Technical Papers
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Hideyuki MONGI, Masakazu ARITAArticle type: Technical Papers
2017 Volume 66 Issue 9 Pages 693-698
Published: September 05, 2017
Released on J-STAGE: October 05, 2017
JOURNAL FREE ACCESSIn this study, the elimination of interference in a diphenylcarbazide (DPCI) spectrophotometric determination of Cr(VI) for a fly-ash leaching test was examined. The determination of Cr(VI) in the fly-ash eluate using DPCI spectrophotometric determination was difficult due to matrix interference. Despite the aluminum-precipitate treatment, the obtained recoveries using the normal-addition method were insufficient. The recoveries of Cr(VI) were improved via reversing the addition procedure of the reagent. Also, high recoveries were simultaneously obtained by the pretreatment of aluminum precipitation. The recoveries were more than 90 % at dilution rates of more than 2.5. Twelve fly-ash leaching solutions were examined using the normal-addition and reverse-addition method at a dilution rate of 5, and their recoveries were compared. Consequently, recoveries of more than 89 % were obtained via the reverse-addition method, whereas the normal-addition methods yielded low recoveries.View full abstractDownload PDF (665K)
Notes
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Takashi MASADOME, Yuichiro NAKAMURA, Keiko MARUYAMAArticle type: Notes
2017 Volume 66 Issue 9 Pages 699-702
Published: September 05, 2017
Released on J-STAGE: October 05, 2017
JOURNAL FREE ACCESSWe report on the development of an optical fluorescence sensor based on the lactone-form Rhodamine B (L-RB) for the detection of an anionic surfactant (AS). The sensor was prepared by embedding the L-RB in a 2-nitrophenyloctyl ether-plasticized poly (vinyl chloride) (PVC) membrane. The optical fluorescence response to AS occurred due to ion-pair coextraction of an AS and a proton into the PVC membrane. The extracted AS enlarges fluorescence of the PVC membrane (λex = 559 nm, λem = 584 nm). The optical fluorescence membrane responds to anionic surfactants, such as dodecylbenzenesulfonate in the concentration range from 0.50 to 5.0 μM. The coexistences of NaCl, KCl, CaCl2, MgCl2, Na2SO4 and NaNO3 at 100 times, a nonionic surfactant (Triton X-100) at 10 times excess to AS did not interfere with the determination of AS within an error of 10 %. The recovery of AS added to environmental water samples was roughly 91 – 104 %. The result indicates that there is small matrix effect on the determination of AS in environmental water samples, and that the present optical fluorescence sensor is applicable for the determination of AS in environmental water samples such as river water and tap water.View full abstractDownload PDF (650K)
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