Vol. 63 No. 11

November, 2014

Annual Topic “Gold” : Research Papers
Spectroscopic Properties and SEM Observations of Au-Ag Core-shell Nanorods Deposited on ITO Plates
Yasuro NIIDOME®1,2,4, Yukiko TSURU1, Yuki HAMASAKI1,2 and Naotoshi NAKASHIMA1,2,3
® E-mail : yniidome@sci.kagoshima-u.ac.jp
1 Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744, Motooka, Nishi-ku, Fukuoka-shi, Fukuoka 819-0395
2 I2CNER, WPI, 744, Motooka, Nishi-ku, Fukuoka-shi, Fukuoka 819-0395
3 CREST, JST, 4-1-8, Hon-machi, Kawaguchi-shi, Saitama 332-0012
4 Present address: Department of Chemistry and Bioscience, Graduate School of Engineering, Kagoshima University, 1-21-35, Korimoto, Kagoshima-shi, Kagoshima 890-8580
(Received June 12, 2014; Accepted July 8, 2014)

Gold-silver (Au-Ag) core-shell nanorods were deposited on ITO plates. The deposition was optimized to suppress the formation of aggregates and to control the densities of the nanorods on the ITO plates. Light-scattering spectra of single nanoparticles were obtained by using a dark-field illumination apparatus and a multichannel spectrophotometer. The spectra indicated that the light scattering originated from surface plasmon of the deposited core-shell nanorods. Dark-field images and SEM images were compared to investigate the relationship between the color of the scattered light and the orientation/aggregation of the core-shell nanorods on the plates. There were four kinds of nanorods on the plates: dimers of nanorods, isolated nanorods “lying” on the plate, isolated nanorods “standing” on the plate, and aggregates containing three or more nanorods. The colors of the four kinds of nanorods were red, green, blue, and white, respectively. The fraction of the “lying” nanorods on the plate was about 50 %. The “standing” nanorods were about 25 %. The dimers and the aggregates were about 12 %, respectively. It was found that the orientation of the nanorods on the plates as well as the aggregation should be taken into account when discussing the spectroscopic properties of the nanorod-deposited plates.

Keywords : gold nanorod; core-shell nanorod; dark-field image; surface plasmon band; anisotropic metal nanoparticle.

Annual Topic “Gold” : Analytical Reports
Evaluation of Neutron Dose Released in the Environment by Activation of Gold
Kouhei N. KUSHITA1, Mariko ATARASHI-ANDOH2 and Hikaru AMANO®3
® E-mail : h-amano@jcac.or.jp
1 Naka Fusion Institute, Japan Atomic Energy Agency, 801-1, Mukoyama, Naka-shi, Ibaraki 311-0193
2 Nuclear Science and Engineering Center, Japan Atomic Energy Agency, 2-4, Shirakatashirane, Tokai-mura, Naka-gun, Ibaraki 319-1195
3 Japan Chemical Analysis Center, 162-1, Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1106
(Received March 20, 2014; Accepted August 8, 2014)

Gold is useful not only for traditional, ordinary human applications as ornaments, coins or electric devices, but also for nuclear and radiation applications. Here we report a study of activated gold for estimating the neutron dose in the environment in the case of the JCO criticality accident that occurred in Tokai, Japan, in 1999. We collected and analyzed 16 gold samples, such as rings, coins or necklaces stored at residents’ houses located in the range of 168 to 568 m from the accident site of the JCO. They indicated activities of gold from 91.9 to 0.322 Bq g−1 as standardized values at 06 : 15 on October 1, 1999, when the criticality reaction had ceased after 20 hours of continuation. The induced radioactivity of gold samples showed a good correlation as a power function of distance. The induced radioactivity of gold is discussed with the reference data in order to estimate dose equivalent in the environment around the JCO. This paper gives an example showing the usefulness of gold in the field of nuclear and radiation studies and applications.

Keywords : gold; Au-198; neutron dose; JCO criticality accident; radiation exposure.

Development of Micro Gas Analysis System and Its Applications to Environmental Analysis
E-mail : todakei@sci.kumamoto-u.ac.jp
1 Department of Chemistry, Kumamoto University, 2-39-1, Kurokami, Chuo-ku, Kumamoto-shi, Kumamoto 860-8555
(Received July 2, 2014; Accepted July 31, 2014)

Micro gas analysis system (μGAS) was developed to monitor atmospheric chemical compounds and gases anthropogenically emitted from industries. While there is still no simple and highly sensitive instrument for most of the water-soluble gases, in these works portable and continuous monitoring systems were developed for these gases. A key device was a microchannel scrubber, which has a 20000-times higher collection/preconcentration efficiency compared to a conventional impinger. This allows us to achieve both high sensitivity and high time resolution. Other important techniques were also developed, such as novel liquid handling, miniature reactors, miniature detectors, and gas generator for on-site calibration. The μGAS enables us to measure SO2, H2S, CH3SH, COS, NO, NO2, HONO, HCHO, NH3 and so on at ppbv levels. Urban environment, forest air, volcanic gases, and gases emitted from soils were analyzed using μGAS, and interesting data were presented, such as localized polluted gases. Also, μGAS was useful for investigations of atmospheric chemistries. The most difficult analytical target among the above-mentioned gases was nitric oxide, NO, because NO is not water soluble, but monitoring of NO in breath air was successful with μGAS. A spreadsheet was developed to simulate the collection efficiency, and was utilized to design channel scrubbers. Thus, the developed channel device was applied to separate gaseous and particulate HCHO, and HCHO was found in particulate matter. The partitioning of HCHO between the gas phase and particulate matter was first investigated.

Keywords : micro gas analysis system (μGAS); on-site analysis; flow control; micro detector; breath; odor analysis; air pollution monitorin.

Technical Papers
Simultaneous Collection of Volatile Organic Compounds and Carbonyls in Mainstream Cigarette Smoke from Japanese Cigarettes Using a Sorbent Cartridge Followed by GC/MS and HPLC
Rina IZU1,2, Shigehisa UCHIYAMA®1, Kanae BEKKI1, Yohei INABA1, Hideki NAKAGOME2 and Naoki KUNUGITA1
® E-mail : uchiyama@niph.go.jp
1 Department of Environmental Health, National Institute of Public Health, 2-3-6, Minami, Wako-shi, Saitama 351-0197
2 Graduate School of Engineering, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba-shi, Chiba 263-8522
(Received June 10, 2014; Accepted July 25, 2014)

Volatile organic compounds (VOCs) and carbonyl compounds in mainstream cigarette smoke from Japanese cigarettes were measured using solid-sorbent collection, followed by GC/MS and HPLC. As a result, it was shown that the major carbonyl compounds in mainstream cigarette smoke were acetaldehyde (48–56%) and acetone (20–24%); the major VOCs in mainstream cigarette smoke were isoprene (40–57%) and toluene (9–12%), respectively. A tobacco-like product, such as Neo Cedar, is the second kind pharmaceutical product; however, it generated many kinds of carcinogen, such as benzene and furans. Moreover, the total carbonyl compounds generated from Neo Cedar was 1.1–2.0–fold higher than those from commercially available cigarettes. During the collection of mainstream cigarette smoke, generation of VOCs and carbonyl compounds was varied by the condition of the smoking machine. On every puff collection, the collected amount by the 1st puff was different from that of the 2nd puff; therefore, it was suggested that the filter structure of the cigarette influenced the chemical compounds in the mainstream cigarette smoke.

Keywords : mainstream cigarette smoke; carboxen 572; volatile organic compounds; carbonyl compounds; Neo Cedar.

Development of Ultra-violet Light-emitting Diode Based Portable Fluorometer and Its Application to Estimations of COD
Yasutada SUZUKI®1, Yoshihiro KIKUTA2, Kazuhiro YAMADA3, Kazuhisa KITADE4, Toshihisa MARUTA4, Junichi ICHIDA4 and Susumu KAWAKUBO1
® E-mail : yamatori@yamanashi.ac.jp
1 Department of Research, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-4-37, Takeda, Kofu-shi, Yamanashi 400-8510
2 Department of Education, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-4-37, Takeda, Kofu-shi, Yamanashi 400-8510
3 Faculty of Engineering, University of Yamanashi, 4-3-11, Takeda, Kofu-shi, Yamanashi 400-8511
4 Tokai Techno Co., Ltd., 2-4-18, Umaokoshi, Yokkaichi-shi, Mie 510-0023
(Received June 30, 2014; Accepted July 31, 2014)

A portable fluorometer using an ultraviolet LED (UV-LED) and a photomultiplier tube module as a light source and a detector, respectively, has been developed to estimate the chemical oxygen demand (COD) value of river-water, seawater and industrial wastewater samples. The fluorescence intensities of samples (excitation wavelength, 340 nm; emission wavelength, 450 nm) were measured by this fluorometer. Their correlation to the COD values obtained by the official titration method using permanganate as an oxidant (CODMn) was studied. The equations for the correlation at different sampling points were not identical; therefore, it should be built for every sampling point. When the sample was taken from a specific point, the time course of its fluorescence intensity versus the CODMn value showed a good correlation. In the case of multi-point sampling from Ise Bay, their correlation was good, if the sampling point was not nearby an estuary. For industrial waste-water, the CODMn of the sample from a factory whose operational condition did not change drastically, can be estimated. This flurometer has additional functions to measure the color unit and turbidity of the sample by an absorbance measurement.

Keywords : COD; ultraviolet light-emitting diode; fluorometer; seawater; wastewater.

Photocatalytic Performance of Prussian Blue-loaded Tungsten Oxide for Photodegradation of Acetaldehyde
Nobuyuki KISHIKAWA®1, Hiroyasu TSUGE1, Satoru KAWASE1 and Satomi ONO1
® E-mail : kishikawa.nobuyuki@nmiri.city.nagoya.jp
1 Nagoya Municipal Industrial Research Institute, 3-4-41, Rokuban, Atsuta-ku, Nagoya-shi, Aichi 456-0058
(Received July 9, 2014; Accepted August 1, 2014)

We prepared a new visible light-responsive photocatalyst, tungsten oxide, supported with Prussian blue (PB-WO3) by a kneading method. The photocatalytic performance of PB-WO3 was improved to photodegrade acetaldehyde completely under visible light. We investigated the formation rate constant of carbon dioxide (CO2) generated by the photodegradation of acetaldehyde, in order to compare the photocatalytic performance of PB-WO3 to that of tungsten oxide supported with copper oxide (CuO-WO3), which was reported previously. As a result, the formation rate constant of CO2 in PB-WO3 indicated 2.1 × 10−2 min−1, which was nearly twice as much as that in CuO-WO3. When we investigated the PB-WO3 after completion of the photodegradation of acetaldehyde to find a factor for the improvement of the photocatalytic performance of PB-WO3, decoloration was observed. It was caused by the reduction of PB by exited electron. It was suggested that the oxidation reaction proceeded effectively on a positive hole, because the reduced PB supported on WO3 prevented recombination of the excited electron. Also, the photocatalytic durability of PB-WO3 was better than that of CuO-WO3, which was evaluated based on the decrease of the formation rate constants of CO2 by repeating the photodegradation of acetaldehyde.

Keywords : photcatalyst; visible light; tungsten oxide; prussian blue; air purification.

Analytical Reports
SI-traceable Purity Evaluation of Non-protein Amino Acid as Reference Materials by Using 1H NMR Spectroscopy
Naoki SAITO®1, Takeshi SAITO1, Taichi YAMAZAKI1, Hisashi KATO1 and Toshihide IHARA1
® E-mail : nao-saitou@aist.go.jp
1 National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1, Umezono, Tsukuba-shi, Ibaraki 305-8563
(Received May 30, 2014; Accepted July 1, 2014)

In recent years, it was become increasingly important to conduct quantitative analyses of several kinds of protein and non-protein amino acids in the human blood. By doing so, it is possible to detect cancer focus positivity at an early stage by monitoring profile of their concentrations. In clinical tests that strongly require high reliability of analytical values, it is essential to use amino acid reference materials that are traceable to the International System of Units (SI). However, SI-traceable reference materials of non-protein amino acids are not generally supplied worldwide. Although it is generally used in the titration method for purity evaluations of amino acid reference materials, purity evaluations using this method require much time and a large amount of sample. On the other hand, Nuclear Magnetic Resonance (NMR) spectroscopy is a rapid quantitative method that is not only SI-traceable, but also requires a small amount of the sample. In this study, we demonstrated purity evaluations of 20 kinds of non-protein amino acids by using 1H NMR. To verify the analytical value, a titration method was used. From our results, the accuracy of the analytical value was evaluated to be approximately 1% by optimizing the experimental conditions for each amino acid, such as the kinds of solvent. Furthermore, the difference in the analytical values between 1H NMR and titration was 0.5% or less. Therefore, it was confirmed to able to perform rapid and accurate evaluations of the purity of non-protein amino acid reference materials by using 1H NMR spectroscopy.

Keywords : non-protein amino acids; 1H NMR; SI-traceability; purity evaluation.

Validation of Plate-type Cell for Micro-Raman Analysis of Liquid Sample
Akiko YAMAKOSHI®1, Yoshiaki ARATA2, Yasuo HASEGAWA2, Masayuki TAKASHIMA2, Toshihide TSUKATANI1 and Susumu YONEZAWA2
® E-mail : a-yamakoshi@niccachemical.com
1 Corporate Research & Innovation Center, NICCA CHEMICAL CO., LTD, 4-23-1, Bunkyo, Fukui-shi, Fukui 910-8670
2 Headquarters for Innovative Society-Academia Cooperation, Fukui University, 3-9-1, Bunkyo, Fukui-shi, Fukui 910-8507
(Received April 2, 2014; Accepted August 11, 2014)

Recently, the use of the Micro-Raman spectrometer for the analysis of chemical materials is attracting attention in applied chemistry and advanced technologies due to the easiness of measurement. However, in the case of a liquid sample, there is some difficulty to analyze it, especially in focusing the laser beam on a transparent liquid sample accurately by using conventional vessels, such as the NMR tube and capillaries. We report here on the validation of a newly-designed cell for Micro-Raman spectroscopy that could more easily analyze a liquid sample than using conventional vessels. This cell is a small rectangular block (30 × 30 × 15 mm) made of aluminum alloy having a cylindrical hole (Φ10 × 5 mm) at center of the surface. First, the hole is filled with an aqueous solution or organic solvent, and then covered with a thin glass plate. By focusing the laser beam anywhere on the bottom surface of the hole, a high signal with sufficient intensity is easily detected. Similarly, a measurement using a cell made of another material, such as stainless steel, glass or polypropylene (PP) is tested. Finally, we conclude that aluminum alloy is the most suitable to be used for the cell material, due to its overall signal intensity, workability of material, low cost, resistance to chemicals and no interference to the Raman signal.

Keywords : Micro-Raman spectroscopy; liquid cell.