Vol. 59 No. 10

October, 2010

Research Papers
Simple Spectrophotometric Determination of Trace Amounts of Zinc in Environmental Water Samples Using Aqueous Biphasic Extraction
Masami Shibukawa1, Daisuke Shirota1, Shingo Saito1, Shin Nagasawa2, Kazunori Saitoh2 and Hiroaki Minamisawa3
1 Graduate School of Science and Engineering, Saitama University, 255, Shimo-Okubo, Sakura-ku, Saitama-shi, Saitama 338-8570
2 Department of Applied Molecular Chemistry, College of Industrial Technology, Nihon University, 1-2-1, Izumi-cho, Narashino-shi, Chiba 275-8575
3 Department of Liberal Arts and Basic Science, College of Industrial Technology, Nihon University, 2-11-1, Shin-ei, Narashino-shi, Chiba 275-8576
(Received 27 July 2010, Accepted 17 August 2010)

A simple and highly selective and sensitive extraction spectrophotometric method is presented for the determination of trace amounts of zinc in environmental water samples. The method is based on the separation and preconcentration of zinc as its thiocyanate complex by aqueous biphasic extraction and subsequent determination by spectrophotometry. As a chromogenic reagent for the spectrophotometric determination of zinc, 5-(5-Bromo-2-pyridylazo)-5-[N-n-propyl-N-(3-sulfopropyl)amino]-phenol (5-Br-PAPS) was used. Aqueous biphasic extraction can be performed by dissolving polyethylene glycol and sodium sulfate in a water sample. A rapid phase separation technique for this aqueous biphasic system was developed using thermal convection so that the extraction of zinc can be accomplished within 7 minutes without mechanical centrifugation. The calibration curve is linear in the concentration range of 0〜200 μg L−1 and the determination limit calculated with ten-times the standard deviation of the reagent blank value is 1.6 μg L−1. Interferences from foreign metal ions were removed by separation with aqueous biphasic extraction and masking with suitable reagents for individual metal ions. The proposed method was applied to the determination of zinc in tap water and river water samples. The obtained results were in good agreement with those obtained by inductively coupled plasma atomic emission spectrometry.

Keywords : zinc ; aqueous biphasic extraction ; spectrophotometric method ; polyethylene glycol ; 5-Br-PAPS.

Technical Papers
Rapid Analytical Method of Water Samples for High Fish Toxicity Pesticides with GC/MS and LC/MS/MS
Tatsuo Yoshida1 and Toshiaki Tobino1
1 Kumamoto Prefectural Institute of Public-Health and Environmental Science, 1240-1, Kurisakimachi, Uto-shi, Kumamoto 869-0425
(Received 24 March 2010, Accepted 13 August 2010)

The authors have developed a simple, rapid analytical method to be used with water samples for 68 high fish toxicity pesticides. Forty-eight components of those were measured with gas chromatography/mass spectrometry (GC/MS). Twenty components that are difficult to be measured with GC/MS were measured with liquid chromatography/tandem mass spectrometry (LC/MS/MS). For the pesticides to be measured with GC/MS, distilled water with standard pesticides was loaded in a macroporous diatomaceous earth column. As a result of studying the dissolution medium, when 150 mL of ethyl acetate was used, 87〜101% of recovery, which was a satisfactory value, was obtained for all components. As the result of a recovery test with distilled water, mineral water and river water as samples by combining the GC/MS measurement under this condition and the LC/MS/MS measurement for which the sample was directly diluted in acetonitrile, 84〜105% of recovery, which was a satisfactory value, was obtained for all components. The operation time of this method is as short as approximately one hour. Moreover, as an advantage, sample quantities necessary for the analysis are as small as 20 mL for GC/MS and 5 mL for LC/MS/MS ; therefore, the total quantity is 25 mL. It is expected that this method will play an important role for clarifying the causes of fish mortality incidents.

Keywords : GC/MS ; LC/MS/MS ; pesticide ; high fish toxicity ; water.

Research Papers
Determination of Trace Elements in Coffee Beans by XRF Spectrometer Equipped with Polarization Optics and Its Application to Identification of Their Production Area
Takao Akamine1, Akiko Otaka1, Akiko Hokura2, Yuji Ito3 and Izumi Nakai1
1 Department of Applied Chemistry, Faculty of Science, Tokyo University of Science, 1-3, Kagurazaka, Shinju-ku, Tokyo 162-8601
2 Department of Green & Sustainable Chemistry, School of Engineering, Tokyo Denki University, 2-2, Kanda-Nishikicho, Chiyoda-ku, Tokyo 101-8457
3 Kirin Beverage Co., Ltd., 6-26-1, Jingumae, Shibuya-ku, Tokyo 150-0001
(Received 16 April 2010, Accepted 18 August 2010)

The production area of coffee beans becomes a brand name, which gives reputations for the products, which is related to the price. This leads to room for mislabeling the products by unscrupulous market dealers. A rapid and easy method for the analysis of trace-element composition of coffee beans, which could be a good indicator of their production area, was studied in the present work. Coffee beans of 6 different regions (Brazil, Colombia, Vietnam, Indonesia, Tanzania, Guatemala) were analyzed by using a highly sensitive X-ray fluorescence spectrometer with three dimensional polarization optics. The experimental conditions were optimized so as to analyze 6 elements (Mn, Fe, Ni, Rb, Sr, Ba) in coffee beans, and linear calibration curves were obtained for the quantitative analysis of those elements. The analytical results were used in principal-component analysis to classify the coffee beans according to the geographical origin, which results in a successful characterization of the 6 production areas. It is found that roasted beans can be used with the same criterion as their green beans. Consequently, a rapid and easy way for the characterization of the geographic origin of coffee beans has been established in this study.

Keywords : coffee beans ; X-ray fluorescence analysis ; trace elements ; geographic origin ; multivariate analysis.

Spectrophotometric Determination of Heparin and Its Related Compounds with o-Carboxyphenylfluorone-Iron(III) Complex
Toshiki Kouda1, Saeko Tamaki1, Kanako Miyachi2, Kenzou Moriyama2, Shigefumi Morimoto3, Takako Yamaguchi1 and Yoshikazu Fujita1
1 Osaka University of Pharmaceutical Sciences, 4-20-1, Nasahara, Takatsuki-shi, Osaka 569-1094
2 Depertment of Hospital Pharmacy School of Medicine, Kinki University, 377-2, Ohno-Higashi, Osaka-Sayama-shi, Osaka 589-8511
3 Depertment of Phamacy, Osaka Minami Medical Center, National Hospital Organization, 2-1, Kidohigashi, Kawachinagano-shi, Osaka 586-8521
(Received 10 March 2010, Accepted 30 August 2010)

A new method was developed for the quantitative determination of heparin and its related compounds. This method is based on color reactions of ternary complex formation among Iron(III), o-carboxyphenylfluorone and heparin in the presence of a nonionic surfactant. Beer’s law was obeyed in the range of 0.1〜1.2 μg/mL for heparin. The molar absorptivity and the relative standard deviation were 4.6 × 106 L mol−1 cm−1 and 1.33% (n = 5), respectively. The effect of some coexisting substances in the reaction have been investigated, and results show that the selectivity of the method is good. The proposed method should be very useful for a simple and sensitive determination of heparin and its related compounds.

Keywords : spectrophotometry ; heparin ; o-carboxyphenylfluorone ; Fe(III) complex.

Technical Papers
Simultaneous Determination of Nitrite, Nitrate, and Ammonium Ions in Lake and River-Water Samples by Ion Chromatography
Masahito Tanaka1, Hideto Ohguni1, Katsuhiko Adachi2, Tomoaki Tsumura2, Takeshi Hirokawa3 and Kazuaki Ito1,2
1 Cluster of Biotechnology and Chemistry Systems, Graduate School of Systems Engineering, Kinki University, 1, Umenobe, Takaya, Higashi-Hiroshima-shi, Hiroshima 739-2116
2 Department of Biotechnology and Chemistry, School of Engineering, Kinki University, 1, Umenobe, Takaya, Higashi-Hiroshima-shi, Hiroshima 739-2116
3 Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, 1-4-1, Kagamiyama, Higashi-Hiroshima-shi, Hiroshima 739-8527
(Received 30 June 2010, Accepted 22 August 2010)

The simultaneous determination of inorganic nitrogen species (nitrite, nitrate, and ammonium ions) in lake and river-water samples was examined by ion chromatography. Nitrite and nitrate ions were separated on a monolith type of ODS columns equilibrated with DDAB (dilauryldimethylammonium bromide) using 0.5 M sodium chloride+5 mM phosphate buffer (pH = 5.0) as the eluent and they were detected by UV at 225 nm. Whereas ammonium ion was detected at 710 nm as an indophenol blue derivative after the post-column reaction of ammonium in the presence of dichloroisocyanurate and 1-naphthol. Calibration curves of all ions showed good linearity (more than R2 = 0.998) in the range of 0〜10 mg/L. The concentration and pH of reagents, the length of reaction coil, and the flow rate of eluent were optimized. The detection limits (S/N = 3) of nitrite, nitrate, and ammonium ions were 0.2, 0.7, and 2.7 μg/L, respectively. Also, the repeatability (0.1 mg/L, n = 5) was below 0.15% (retention time), 1.13% (peak area), and 0.88% (peak height). The present method was applied to the simultaneous determination of inorganic nitrogen species in lake and river-water samples. The recovery by analysis of spiked samples was in the rage of 94〜108%.

Keywords : ion chromatography ; post-column reaction ; nitrite ion ; nitrate ion ; ammonium ion.

Development of Colorimetric Reagents and Easy Monitoring Devices for the Selective Detection of Formaldehyde and Their Practical Uses
Yoshio Suzuki1, Takahiro Fujikawa2, Nobuo Nakano3, Yasuhiro Terauchi3 and Koji Suzuki4
1 Biotechnology Industrialization Center, National Institute of Advanced Industrial Science and Technology (AIST), c/o Katayanagi Advanced Research Laboratories, Tokyo University of Technology, 1404-1, Katakura, Hachioji-shi, Tokyo 192-0982
2 Kanto Chemical Co. Inc., 3-2-8, Nihonbashi Honcho, Chuo-ku, Tokyo 103-0023
3 Riken Keiki co., Ltd., 2-7-6, Azusawa, Itabashi-ku, Tokyo 174-8744
4 Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama-shi, Kanagawa 223-8522
(Received 25 December 2009, Accepted 12 April 2010)

Formaldehyde (HCHO) is used in the workplace and comes from an adhesive used in the manufacture of resins, plastics, coatings, and fabrics. HCHO emitted from the furniture and walls in the rooms injures the eyes, nose and respiratory organs, and causes allergies, which is called the Sick building syndrome. We designed and synthesized new colorimetric HCHO-sensing molecules that possess an enaminone structure. As an application of a sensing molecule, a hand-held instrument to monitor indoor HCHO gas (FP-30) and formaldehyde test paper (Dr. Sick House) has been developed and is commercially available. The present paper describes technical explanations about the sensing molecule and monitoring devices, as well as their trends.

Keywords : formaldehyde ; colorimetric reagent ; portable monitor ; test paper ; indoor and workplace environment.

Magnetic Susceptibility Measurement of Single Micro-Particle by Magnetophoretic Velocimetry
Masayori Suwa1 and Hitoshi Watarai1
1 Department of Chemistry, Graduate School of Science, Osaka University, 1-1, Machikaneyama, Toyonaka, Osaka 560-0043
(Received 14 January 2010, Accepted 20 April 2010)

It has been highly required to analyze environmental or biological micro-particles noninvasively and nondestructively, since they have each characteristic function in the surface and inside the individual particle. Magnetophoretic velocimetry is a novel migration method, that allows us to measure the magnetic susceptibility of a single micro-particle, and can satisfy this requirement. A high magnetic field gradient generated by a superconducting magnet and a pair of pole pieces were used, in order to enhance the sensitivity of magnetophoretic velocimetry. The apparatus for observation of magnetophoresis in the gradient was constructed. The magnetic susceptibility of a micro-droplet adsorbed by a paramagnetic Dy(III) complex was measured, and reciprocally depended on the radius of the droplet. Dy(III) on the interface could be determined from this dependency. Furthermore, a photo-induced spin transition of single microcrystal of Co-Fe Prussian blue analogues could be observed from an abrupt increase of magnetophoretic velocity after pulse laser irradiation.

Keywords : magnetophoresis ; magnetic susceptibility ; feeble magnetism ; adsorption on liquid-liquid interface ; size effect ; photo-induced spin transition.

Research Papers
Evaluation of ABS Resin Disk Certified Reference Materials for Heavy Metal Analysis by X-ray Fluorescence Analysis
Masaki Ohata1, Toshihiro Kidokoro1, Masayasu Kurahashi1 and Akiharu Hioki1
1 Inorganic Standards Section, Inorganic Analytical Chemistry Division, National Metrology Institute of Japan (NMIJ), National Institute of Advanced Science and Technology (AIST), Tsukuba Central 3-9, 1-1-1, Umezono, Tsukuba-shi, Ibaraki 305-8563
(Received 24 March 2010, Accepted 16 June 2010)

ABS resin disk certified reference materials (CRMs) for heavy-metal analysis (NMIJ CRM 8105-a, NMIJ CRM 8106-a, NMIJ CRM 8115-a and NMIJ CRM 8116-a) were evaluated using an energy dispersive X-ray fluoresence (ED-XRF) analysis. The homogeneities of elements for both among-disks and within-disk were evaluated by ED-XRF analysis without any sample pre-treatment, which were similar to those evaluated by ICP-MS analysis after a sample digenstion procedure. The normalized XRF sensitivities for Cd, Cr and Pb in different ABS resin disk CRMs were compared, and the differences among them for those ABS resin disks that have similar matrices were observed. Moreover, Hg in those ABS resin disk CRMs was stable for long-term X-ray irradiation during ED-XRF analysis.

Keywords : ABS resin disk CRMs for Cd, Cr, Hg and Pb analysis ; RoHS directive ; ED-XRF analysis ; stability ; XRF sensitivity ; homogeneity.

Atomic Absorption Spectrometry in High Absorbance Region Utilizing Wavelength-Variable Laser
Tomoharu Ishida1 and Takanori Akiyoshi2
1 Analysis & Characterization Research Dept., Steel Research Laboratory, JFE Steel Corporation, 1, Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba 260-0835
2 Standardization Center, The Japan Iron and Steel Federation, 3-2-10, Nihonbashi-Kayabacho, Chuo-ku, Tokyo 103-0025
(Received 31 March 2010, Accepted 28 June 2010)

A new atomic absorption spectrometry (AAS) equipped with a wavelength-variable laser has been investigated in order to satisfy the potential needs for measuring of the concentration of dense atomic vapor to control the quality of products in the field of manufacturing premises. The application of AAS is limited because the intensity of the hollow cathode lamp (HCL) is so weak that the dynamic range is narrow in spite of its versatility and simple device configuration. A wavelength-variable laser was applied as the light source of AAS. In the case where the center wavelength of the laser was fit to the absorption maximum of Mn, the measurable region of the absorbance would be magnified by more than one hundred compared with the conventional method. The absorbance was proportional not to the Mn solution concentration, but to the logarithm of the concentration in the high absorbance region. The calculated results of the absorbance supported the experimental results.

Keywords : atomic absorption ; laser light source ; wavelength-variable laser ; high absorbance region.

Analytical Reports
Determination of Phenolic Compounds in Waste Water by 4-Aminoantipyrine Spectrophotometry after Methyl Benzoate Extraction
Emi Morita1 and Eiko Nakamura1
1 Graduate School of Environment and Information Sciences Yokohama National University, 79-2, Tokiwadai, Hodogaya-ku, Yokohama-shi, Kanagawa 240-8501
(Received 26 January 2010, Accepted 11 June 2010)

A methyl benzoate extraction procedure was studied for determining small amounts of phenol compounds in waste in the 4-aminoantipyrine spectrometry. The proposed procedure was as sensitive as the typical chloroform extraction procedure. The precision of repeated tests (n = 4) was ca. 0.7% on phenol solution (0.20 μg as phenol/mL). The detection limit was 0.004 μg as phenol/mL. Good results were obtained in recovery tests using both waste water and river water.

Keywords : phenol ; 4-aminoantipyrine ; methyl benzoate extraction.

Quantitative Analysis of Amorphous Contents in Photocatalytic Titania Powders
Satoru Kawase1, Ken-ichi Sugimoto2, Rise Fujiwara3 and Satomi Ono1
1 Nagoya Municipal Industrial Research Institute, 3-4-41, Rokuban, Atsuta-ku, Nagoya-shi, Aichi 456-0058
2 Aichi prefecture, 3-1-2, San-nomaru, Naka-Ku, Nagoya-shi, Aichi 464-8501
3 Aichi Industrial Technology Institute, 1-157-1, Onda-cho, Kariya-shi, Aichi 448-0013
(Received 30 April 2010, Accepted 5 July 2010)

Titania powders with different crystallinity were prepared from alkoxide-derived amorphous titania powders by heat-treatments at temperatures of less than 600°C. The amorphous and anatase contents of titania powders were analyzed by measuring the heat of crystallization in DSC and by X-ray diffraction measurements with the Rietveld method. Amorphous powders showed an exothermic peak due to the crystallization of amorphous to anatase at around 360°C in DSC. The heat of crystallization was 163 J/g. The amorphous contents of titania powders decreased with an increase of the heat-treatment temperature. On the other hand, the amorphous powder began to crystallize under a heat treatment at 300°C in the XRD profile. The intensity of diffraction lines attributed to anatase became stronger with an increase of the heat-treatment temperature. The amorphous contents of titania powders decreased with the heat-treatment temperature in an analysis of the Rietveld method. There are linear relationships between the amorphous contents and the temperature in both results from DSC and the Rietveld methods. We examined the relationship between the crystallinity of the tiatnia powders and their photocatalytic activity. The photocatalytic performances of titania powders were evaluated upon the removal of acetaldehyde. The results showed that the photocatalytic activity of titania powders increased with an increase of the anatase contents.

Keywords : titania ; powder ; amorphous ; Sol-Gel method ; DSC ; the rietveld method ; quantitative analysis.