BUNSEKI KAGAKU Abstracts

Vol. 56 No. 5

May, 2007


Reviews
Recent Advances in Materials for Separation
Akira Sano1 and Hiroshi Nakamura1
1 Analytical Chemistry, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641, Yamazaki, Noda-Shi, Chiba 278-8510
(Received 15 November 2006, Accepted 30 January 2007)

Recent developments in packing materials for high-performance liquid chromatography (HPLC) and capillary electrochromatography (CEC) have been discussed. Silica gel and its derivatives have been used predominantly as column packing materials for HPLC owing to their high resolution and mechanical strength. The fact that silica gel matrixes are chemically unstable under acidic and basic conditions facilitated the developments of silica matrixes with stable polymer-coating and organic- and inorganic-hybrid silica matrixes, which were used for the preparation of reversed-phase sorbents. Studies on titania and zirconia have progressed especially due to their extreme robustness and unique chemo-affinity for organic phosphates. Titania and zirconia also play important roles in phosphoproteome analysis. Various intelligent materials such as temperature- and photo-sensitve stationary phases, bio-affinity sorbents, molecular imprinting polymers and molecular shape-selective packing materials were reported. The invention of monolith columns is a major innovation in column technology. However, our description about monolith columns was shortened because the related topics were reviewed previously by many authors.

Keywords : packing material; silica gel; titania; zirconia; intelligent material; HPLC; CEC.

Accounts
Direct Analysis of Minor Organic Components in Various Polymers and Biomaterials by Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry
Hajime Ohtani1 and Yasuyuki Ishida2,3
1 Department of Materials Science and Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya-shi, Aichi 466-8555
2 EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa-ku, Nagoya-shi, Aichi 464-8603 3 Present address, Department of Biological Chemistry, College of Bioscience and Biotechnology, Chubu University, 1200, Matsumoto-cho, Kasugai-shi, Aichi 487-8501
(Received 13 November 2006, Accepted 2 February 2007)

Novel methods for the direct analysis of small amounts of organic components in various polymeric and/or biomaterials were developed by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) using solid sampling techniques while avoiding troublesome solvent extraction. At first, a trace amount of oligomeric hindered amine light stabilizer (HALS) in polypropylene (PP) materials was directly analyzed by solid sampling MALDI-MS. In addition, using an internal standard material, the HALS contents in PP could be determined. Moreover, the light-stabilizing action of the HALS component was also discussed through solid sampling MALDI-MS measurements of UV-irradiated PP samples. Next, the condensed tannin components in wood powder samples were analyzed by solid sampling MALDI-MS. The obtained mass spectra showed a series of peaks corresponding to the sodium ion adducts of the condensed tannin oligomers up to around m/z 3000. Then, the intact lipids in a single zooplankter individual at the level of a few tenths of a microgram were analyzed by a direct sampling MALDI-MS. The observed mass spectra of the single zooplankter samples showed a series of ions generated from phospholipids and neutral lipids; this means that the relative quantity between “structural lipids” (phospholipids) and “storage lipids” (neutral lipids) can be estimated for an individual zooplankter, which should give us a good clue to elucidate the roles of each class of lipids during growth. Finally, phospholipids in whole bacteria were characterized by solid sampling MALDI-MS using a so-called “on-probe” sample pretreatment. By this method, a series of peaks derived from phospholipids in gram-negative bacteria were readily observed in the mass spectra. Furthermore, even for gram-positive bacteria with a thicker peptidoglycan, the phospholipid components in whole bacteria were able to be clearly detected by this method using trifluoroacetic acid as an additional reagent for the promoted decomposition of the bacterial cell wall.

Keywords : matrix-assisted laser desorption-ionization mass spectrometry; solid sampling technique; direct analysis; hindered amine light stabilizer; tannin; lipids; zooplankter; whole bacteria.

Research Papers
Simultaneous Determination of Residual Veterinary Drugs in Muscle by On-Line Solid Phase Extraction/High-Performance Liquid Chromatography/Tandem Mass Spectrometry
Misako Tagiri-Endo1 and Noriaki Yanagita1
1 Institute of Public Health and Environment, Miyagi Prefectural Government, 4-7-2, Saiwai-cho, Miyagino-ku, Sendai-shi, Miyagi 983-8666
(Received 25 December 2006, Accepted 17 February 2007)

A rapid simultaneous assay was developed for determining 63 veterinary drugs in bovine, porcine, and poultry muscles by on-line solid phase extraction (on-line SPE)/high-performance liquid chromatography/tandem mass spectrometry (MS/MS). The drugs were extracted from muscle samples with acetonitrile-methanol (4 : 1, v/v). The extracts were evaporated, and the residues were dissolved with acetonitrile-water (1 : 1, v/v). The samples were injected into an on-line SPE column packed with Oasis HLB using 0.1% formic acid as a mobile phase, to separate drugs from interfering substances and retain them on it. The drugs were introduced onto an analytical column using 0.1% formic acid- acetonitrile in a gradient mode by column switching and directed into MS/MS. Under the optimal analytical conditions, the repeatability of the retention time and the peak area of standard compounds were less than 1% and 12%, respectively. The recoveries of 63 drugs from muscle spiked at 20 ng/g were 45.8〜153%. The detection limits were less than or equal to10 ng/g.

Keywords : veterinary drugs; LC/MS/MS; on-line solid phase extraction; column switching; muscle.

Stability of Sodium Thiosulfate Solution and Constant-Current Coulometric Iodometric Titration of Potassium Iodate
Tatsuhiko Tanaka1, Hiroya Hayashi1, Yoshikazu Komiya1, Hidenori Nabekawa1 and Hideo Hayashi1
1 Faculty of Engineering, Tokyo University of Science, 1-3, Kagurazaka, Shinjuku-ku, Tokyo 162-8601
(Received 25 January 2007, Accepted 8 March 2007)
The effective purity of potassium iodate was determined by adding it to a sufficiently acidified potassium iodide solution, followed by the addition of a measured excess of a standard sodium thiosulfate solution and back-titrating the excess with anodically generated iodine. First, the preparation and stability of a sodium thiosulfate solution were investigated. If pure, freshly boiled and cooled water was used to dissolve an analytical-grade sodium thiosulfate pentahydrate, the decomposition of the thiosulfate solution due to oxygen, carbon dioxide and thiobacteria was inhibited, and the concentration of ca. a 0.5 mol kg-1 thiosulfate solution stored in a Teflon bottle was unchangeable, even immediately after preparation, and was stable for at least one month without the addition of any preservatives. Tightly stoppered plastic containers were appropriate for preserving a thiosulfate solution. The effective purity of a potassium iodate reference material (certified value 99.98%±0.01%) was found to be 99.968% with a relative standard deviation of 0.018% (n=10), and the assay of potassium iodate was successfully determined by coulometric iodometric titration with the standard thiosulfate solution.
Keywords : assay of potassium iodate; stability of sodium thiosulfate solution; constant-current coulometry; reference material.

Technical Papers
Speciation of Sulfur in Petroleum Liquids by Gas Chromatography/Inductively Coupled Plasma Mass Spectrometry
Hiroaki Tao1, Tetsuya Nakazato1, Mikio Akasaka1,2 and Shinya Satoh1
1 National Institute of Advanced Industrial Science and Technology (AIST), 16-1, Onogawa, Tsukuba-shi, Ibaraki 305-8569
2 Japan Industrial Technology Association (JITA), 1-1-1, Higashi, Tsukuba-shi, Ibaraki 305-0046
(Received 14 December 2006, Accepted 7 March 2007)

A speciation method for sulfur in petroleum liquids by gas chromatography/inductively coupled plasma mass spectrometry (GC/ICP-MS) was developed. From an investigation of the effects of the ICP-MS operating conditions on the background intensities at m/z 32 and 34, the origin of the contaminated sulfur and the interference of the oxygen molecular ion O2 with the background were clarified, and countermeasures, such as an alternative GC/ICP-MS interface without using silver brazing, purification of Ar gas by a getter, and alternate cone materials, were quantitatively evaluated for decreasing this contamination and interference. The dependence of the sensitivity and the matrix effect on the ICP output power were also examined, and high sensitivity and low matrix effects were obtained at higher output power. The detection limit was around 0.6 ng S mL-1, corresponding to 0.05 pg at the ICP-MS detector, taking account of the GC split ratios, which were 2 or 3 orders of magnitude superior to those with GC/FPD and GC/AED and equivalent, or 10 times superior to those with GC/pulsed FPD and GC/SCD. The detector response to sulfur is considered to be essentially equimolar for all sulfur species, but in practice, the sensitivity decreased slightly for a species with a high boiling point. It was speculated that the reason for the low sensitivity was not due to an inefficient ionization in ICP, but due to discrimination at the GC injection port, or decomposition in the GC column. The present method was successfully applied to petroleum liquids, such as naphtha, gasoline, kerosene and light oil. These results were also compared with those by GC/AED and GC/SCD, and showed satisfactory agreement. Although the quenching effects by concomitant hydrocarbons were found to be slightly larger than those observed with SCD, the present method was superior in sensitivity to other conventional methods, and is expected to contribute to the development of low-sulfur gasoline for automobiles and fuels for fuel cells.

Keywords : GC/ICP-MS; sulfur; petroleum; speciation; fuel cell.

Notes
Analysis of Small Components and Unknown Species in Dye Mixture by Different Calculation Method of Regression Analysis
Akira Matsushita1, Shuji Okuyama2, Toshiyuki Mitsui3 and Yukihiro Ozaki4
1 Forensic Science Laboratory, Osaka Prefectural Police Headquarters, 1-3-18, Honmachi, Chuo-ku, Osaka-shi, Osaka 541-0053
2 Criminal Investigation Laboratory, Aichi Prefecture Police Headquarters, 2-1-1, Sannomaru, Naka-ku, Nagoya-shi, Aichi 460-8502 3 Data Analysis Laboratory, 1-18-28, Hanazono-cho, Handa-shi, Aichi 475-0833 4 Kwansei Gakuin University, 2-1, Gakuen, Sanda-shi, Hyogo 669-1337
(Received 16 August 2006, Accepted 27 February 2007)

The quantitative analysis of different calculation method of regression analysis (DCR) is performed without a calibration curve and separation process. Also, the mixture ratio of an unknown sample is determined from the coefficient of the multiple regression equation using the measured values of two or more known samples and one unknown sample. In the present work, the mixture ratio of small component in food dye mixture was calculated from 431 absorbance data of known and unknown samples measured by a spectrophotometer. As a result of calculations, a small component in a food dye mixture in an unknown sample was determined very correctly by DCR. The detection limit of the small component in the food dye mixture by this method was about 1%. The reproducibility of the purple dye mixture ratio was examined using a test sample (red dye : purple dye=99.01 : 0.99), and the relative standard deviation from the calculated result was 3.63%. Also, the relative standard deviations of PCR and PLS were 26.36% and 12.9%, respectively. Furthermore, the existence judgment of a non-recognized small component in an unknown sample of food dye was performed based on the difference in the corrected value and the calculated value.

Keywords : different calculation method of regression analysis (DCR); small component in food dye; existence judgment of a non-recognized small component; spectrophotometry.

Analytical Reports
Detection Performance of Dräger Safety Gas Detection Tube for Chemical Warfare Agents
Yasuo Takayama1,2, Ryoji Sekioka1,2, Hiroshi Sekiguchi2, Hisashi Maruko2, Takeshi Ohmori1 and Yasuo Seto1
1 National Research Institute of Police Science, 6-3-1, Kashiwanoha, Kashiwa-shi, Chiba 277-0882
2 Tokyo Metropolitan Police Depaertment, 2-1-1, Kasumigaseki, Chiyoda-ku, Tokyo 100-8929
(Received 11 December 2006, Accepted 13 February 2007)

The detection performance of Dräger safety gas detection tubes for chemical-warfare agents was investigated using authentic compounds. “Phosphoric esther” tubes gave limit of detection (LOD) values of 0.002 (sarin), 0.02 (soman), 0.5 (tabun) and 2.0 (VX) mg/m3 with about 5 min of operation. “Thioether” tubes gave an LOD value of 1.2 mg/m3 (mustard gas) after about 2 min of operation. “Organic arsenic compounds and arsine” tubes gave an LOD of 3.8 mg/m3 (lewisite 1) after about 2 min of operation. “Hydrogen cyanide” tubes gave an LOD of 0.3 mg/m3 (HCN) with less than 1 min of operation. “Cyanogen chloride” tubes gave an LOD of 0.75 mg/m3 (ClCN) with about 3 min of operation. False positive detection was also observed for various simulants.

Keywords : chemical-warfare agents; on-site detector; detection performance; gas detection tube.

Technology Reports
Development of the Certified Reference Materials, Plastics (JSAC 0631, JSAC 0632) for Determination of Hazardous Metals by X-Ray Fluorescence Analysis
Kazuhiko Nakano1, Toshihiro Nakamura1, Izumi Nakai1, Akira Kawase1, Makoto Imai1, Mikio Hasegawa1, Yo-ichi Ishibashi1, Isamu Inamoto1, Kazuhuyu Sudou1, Masaru Kozaki1, Akira Turuta1, Atsushi Bando1, Akihiro Ono1, Kazutoshi Kakita1, Kenichi Takimoto1 and Mamoru Sakata1
1 The Japan Society for Analytical Chemistry, 1-26-2, Nishigotanda, Shinagawa-ku, Tokyo 141-0031
(Received 6 November 2006, Accepted 14 February 2007)

The Japan Society for Analytical Chemistry has developed plastic certified reference materials (CRMs) for the X-ray fluorescent analysis of four hazardous elements: Pb, Cd Cr and Hg in plastics. Disk samples were prepared by filling Al-cylindrical molds with the raw material liquid of polyester resin mixed with hardener and organometallic compounds. Thus 360 candidate reference materials of JSAC 0631 and 0632 were obtained. Both surfaces on prepared disks obtained after 12 h of hardening at room temperature were ground and polished by a milling machine at 4.00±0.05 mm thick. The homogeneity of the prepared disks was shown excellently. An interlaboratory comparison study was performed by 24 laboratory’s participants. In a statistical evaluation for the interlaboratory study, z-scores in the “robust method” were applied in order to reject outlier. The certified uncertainties for prepared CRMs were determined at in the confidence levels of 95%.

Keywords : plastics; polyester resin; certified reference materials; XRF analysis; interlaboratory comparison study; hazardous elements (Pb, Cd, Cr, Hg).

Results of Proficiency Testing for 6th Round Determination of Dioxins in Wastewater based on ISO/Guide 43-1
Yo-ichi Ishibashi1, Shozo Asada1, Hiroyuki Igaki1, Satoshi Tsuruta1, Akihiro Ono1, Kazutoshi Kakita1 and Mamoru Sakata1
1 The Japan Society for Analytical Chemistry, 1-26-1, Nishigotanda, Shinagawa-ku, Tokyo 141-0031
(Received 6 November 2006, Accepted 15 February 2007)

The Japan Society for Analytical Chemistry carried out a sixth proficiency testing for the determination of dioxins (polychlorodibenzo-p-dioxins, polychlorodibenzofurans and dioxin-like polychlorobiphenyls) in wastewater. This proficiency testing of analytical laboratories was based on ISO/IEC Guide 43-1, “Proficiency testing by interlaboratory comparisons”. The testing was carried out from February ’05 to May ’05, with the participation of 105 laboratories. As a result, 93 laboratories (88.5%) were estimated as “satisfactory”, 5 laboratories (4.8%) as “questionable” and 7 laboratories (6.7%) as “unsatisfactory”. Dioxins in wastewater were classified in two groups: existing in SS particulates, and dissolved in water. It was shown from the results that those compounds with a high dissolved state %, such as many CoPCBs, gave a high CV% in their analytical results.

Keywords : dioxins; wastewater; proficiency testing; z score; dissolved state dioxins; particulate state dioxins.

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