Vol. 4 9, No. 6
June, 2 0 0 0
Masumi Mitome, Katsutoshi Ito, Hidetoshi Arakawa and Masako Maeda*
*School of Pharmaceutical Sciences, Showa University, 1-5-8, Hatanodai, Shinagawa, Tokyo 142-8555
(Received 14 January 2000, Accepted 20 February 2000)We have developed a simultaneous determination of phenylalanine (Phe), leucine (Leu) and galactose (Gal) by a semi-micro flow-injection analysis system using an enzyme-immobilized column. This method was applied to preliminary neonatal mass-screening for inborn errors of metabolism. Enzyme-immobilized gel was prepared with Phe, Leu or Gal dehydrogenase using a TSK-gel Tresyl 5PW (Tosoh Co., Tokyo), which was easily linked to the amino group of protein and packed into a column(1.5 i.d.×100 mm). The enzyme-immobilized columns were connected to high-pressure 6-way valves. In the proposed method, the detection limits (S/N=3) of Phe, Leu and Gal were 1.6×10-13, 3.4×10-13 and 1.6×10-13 mol/assay, respectively. The measurable ranges for Phe, Leu and Gal were 0.3-19.6, 0.8-18.4 and 0.4-18.2 mg/dl on the standard dried-blood disc (3 mm i.d.) on filter paper, respectively. The accuracy of an intra-assay with each point of the standard disc (n=5) was less than 2.4%. The mean recoveries (n=11) of Phe, Leu and Gal from a dried-blood disc were 77.4, 78.5 and 97.4%, respectively. Further, we measured the Phe, Leu and Gal concentrations of neonatal blood-disc samples by the proposed method. The levels (mean±SD, n=30) were 1.5±2.1 (Phe), 2.4±1.4 (Leu) and 2.6±2.1 (Gal) mg/dl, respectively. The proposed method could quantitatively measure amino acids and galactose in one dried-blood disc on filter paper for 17 min.
Keywords : neonatal mass-screening; enzyme-immobilized column; phenylketonuria; maple syrup urine disease; galactosemia.
Keitaro Yoshimoto, Emiko Kaneko and Takao Yotsuyanagi*
*Department of Applied Chemistry, Graduate School of Engineering, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8579
(Received 14 January 2000, Accepted 10 April 2000)A visual method has been established for the determination of the urinary protein concentration with Bromochlorophenol Blue (BCPB) and a membrane filter (MF). The acid-dissociation constant of HBCPB- is pKa (OH)=4.2. At pH 3.0, ternary association occurs between HBCPB-, BCPB2- and protein in solution. After the associate is extracted onto a MF, HBCPB- in the associate undergoes a significant color change from yellow to blue upon drying. Free HBCPB- is not extracted onto a MF. The high extractability of the ternary associate and the significant color change provide a sensitive visual method for protein detection. This method can be used to detect human serum albumin in urine visually at concentrations as low as 40 mg/l. There was good agreement between the results obtained for urinary protein by this method and those obtained by the conventional Coomassie Brilliant Blue spectrophotometry. The method reported here can be used as a screening test for low, but increased, protein in urine.
Keywords : protein; urine; visual determination; Bromochlorophenol Blue; membrane filter.
Toshio Yao and Akira Uno*
*Department of Applied Chemistry, College of Engineering, and Research Institute for Advanced Science and Technology, Osaka Prefecture University, 1-2 Gakuencho, Sakai, Osaka 599-8531
(Received 7 January 2000, Accepted 1 February 2000)A flow-injection system with a dual enzyme electrode is proposed for estimating porcine meat freshness, based on the simultaneous detection of polyamines and hypoxanthine as quality indexes of meat freshness. A dual enzyme electrode was prepared by cross-linking putrescine oxidase or xanthine oxidase with bovine serum albumin using glutaraldehyde on each of two silanized platinum disks of a cross-flow dual electrode. Further, a poly(1,2-diaminobenzene) film was hybridized onto the cross-linked enzyme membrane to improve the selectivity by permselective coating of the platinum disk surface. The prepared dual enzyme electrode responded selectively to polyamines and hypoxanthine, respectively, without any interference from oxidizable species or proteins, with an in-parallel arrangement of two sensing parts for the carrier flow direction. Two sensing parts responded linearly to the concentration of polyamines and hypoxanthine, respectively, over the range of 2×10-6~2×10-3 M. The reproducibility of the measurements was 1.1-1.6% RSD. The determination speed was up to 100 samples per hour at a flow rate of 0.7 ml min-1 when a 0.1 M phosphate buffer (pH 8.0) containing 0.1 M NaCl was used as the optimum carrier solution. The present FIA method could be successfully applied to the simultaneous detemination of polyamines and hypoxanthine in extracts from porcine meat stored at 5°C; the amounts of polyamines and hypoxanthine increased with increasing the storage time, particularly after 4 - 9 days.
Keywords : dual enzyme electrode; FIA; estimation of meat freshness; polyamines; hypoxanthine.
Yutaka Itabashi, Mako Kawano*, Tomoya Aoyama and Toshiaki Nakajima**
*Department of Marine Bioresouces Chemistry, Faculty of Fisheries, Hokkaido University, Hakodate-shi, Hokkaido 041-8611
**Material Project, Idemitsu Petrochemical Co., Ltd., 5-6-1, Shiba, Minato-ku, Tokyo 108-0014
A simple method is described for determining the positional distribution of fatty acids in γ-linolenic acid-rich triacylglycerols (TGs). The oils from the filamentous fungus Mucor circinelloides and its variant were analyzed for this purpose. The procedure involved the preparation of sn-1,2(2,3)-diacylglycerols (DGs) by the partial deacylation of TGs with a Grignard reagent, the preparation of 3,5-dinitrophenylurethane (DNPU) derivatives of the DGs, the resolution of the enantiomeric sn-1,2- and sn-2,3-DGs by chiral-phase HPLC, the resolution of molecular species of DGs in each enantiomer group by reversed-phase HPLC, and the determination of the fatty acid composition by gas-liquid chromatography. The positional distributions of the fatty acids were calculated from the fatty acid compositions of the original TGs and the enantiomeric sn-1,2- and sn-2,3-DGs. The results demonstrated the preferential association of γ-linolenic acid to the sn-3 position, followed by the sn-1 position, and then the sn-2 position in both oils.
Keywords : γ-linolenic acid; Mucor circinelloides; chiral-phase HPLC; stereospecific analysis; molecular species.
Yuzo Tamari*
*Konan University, 8-9-1, Okamoto, Higashinada-ku, Kobe-shi, Hyogo 658-0072
(Received 16 December 1999, Accepted 2 April 2000)The selenium contents of a brand of cow's milk and four brands of commercially available infant formulas were investigated from 1989 to 1999. As a pretreatment, each sample was digested with a mixture of nitric acid and perchloric acid; then, all of the selenium(VI) in the mixture was reduced to selenium(IV) by boiling with hydrochloric acid. The selenium concentration was determined by atomic absorption spectrometry with hydride generation. As a result, the selenium contents of a brand of cow's milk (69 samples) were almost constant, with a mean of 19.7±2.3 ng/g, i.e., there was little variation during eleven years. Four brands of infant formulas showed no significant year-variation of selenium content. The selenium contents ranged over 30~51, 31~54, 33~40 and 55~83 ng/g for four brands of formulas available during 1991 to 1999. Using these data, a daily dietary selenium intake of infants has been estimated and discussed.
Keywords : cow's milk; infant formulas; selenium content; selenium intake; hydride generation-AAS.
Akiko Hokura*,**, Sachiko Oguri, Hirotaka Matsuura and Hiroki Haraguchi*
*Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603
**Present address: National Institute for Research in Inorganic Materials, Science and Technology Agency, 1-1, Namiki, Tsukuba-shi, Ibaraki 305-0044
A multielement determination of major-to-ultratrace elements in vegetable samples was carried out by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectrometry (ICP-AES). Spinach samples (0.5 g) were digested with nitric acid and hydrofluoric acid in a Teflon beaker on a hot plate. The decomposed samples were dissolved in a 1 M (=mol dm-3) HNO3 solution containing internal standard elements (Ge, In, and Re, 10 ppb each), and were subjected to multielement analyses by ICP-AES and ICP-MS. As a result, about 40 elements were successfully determined over a wide concentration range from % to ppb level. Spinach samples grown in different production areas were also analyzed in order to understand the influences of the environmental conditions on growth. Among the major and minor elements, the values of the coefficient of variance (CV) for B, Mg, P, and K were <20%, and those for Ca, Na, Al, and Mn were higher than 50%. On the other hand, the values of CV for trace and ultratrace elements were significantly high. Furthermore, the present analytical method was also applied to the determination of major-to-ultratrace elements in various vegetable samples (23 species in 11 families); the similarities and differences of the elemental distributions in vegetables were found in the experimental results.
Keywords : multielement determination; major-to-ultratrace elements; vegetable samples; ICP-AES; ICP-MS.
Hirotaka Matsuura*, Akiko Hokura*,** and Hiroki Haraguchi*
*Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603
**Present address: National Institute for Research in Inorganic Materiasls, Science and Technology Agency, 1-1, Namiki, Tsukuba-shi, Ibaraki 305-0044
(Received 13 January 2000, Accepted 24 April 2000)In order to investigate the multi-elemental composition of green tea leaves as well as chemical species in tea infusions, inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS) were used for elemental analysis and elemental speciation with the aid of size exclusion chromatography (SEC). As a result, the multielement determination of major-to-ultratrace elements in green tea leaves and green tea infusions was carried out by ICP-AES and ICP-MS. About 40 elements in these tea samples could be determined in a wide concentration range of over 8 orders of magnitude. The extraction efficiency of each element was estimated as the ratio of its concentration in tea infusion to that in tea leaves. It was found from the experimental results that the elements in tea leaves could be classified into three characteristic groups, depending on their extraction efficiencies. Furthermore, tea infusions were analyzed by a combined system of SEC, UV absorption detector, and ICP-AES (or ICP-MS) for the speciation of major-to-ultratrace elements. Most of the elements in tea infusions were found to be present as associated complexes with large organic molecules.
Keywords : multielement determination; elemental speciation; tea leaves; ICP-AES; ICP-MS; size exclusion chromatography.
Akemi Yasui and Kumiko Shindoh*
*Ministry of Agriculture, Forestry and Fisheries, National food Research Institute, 2-1-2, Kannondai, Tsukuba-shi, Ibaraki 305-8642
(Received 11 January 2000, Accepted 24 February 2000)The distinction of the geographic origin of brown-rice samples by their trace-element composition was studied. Thirty four kinds of unhulled rice samples (Oryza sativa L. cv. Koshihikari, produced in 1996), including those fertilized in different ways at the same place, were collected from 27 different locations. After hulling, about 1 g of brown-rice (about 50 grains without pulverization) were digested with nitric and perchloric acid. P, K, Mg, Ca, Mn, Zn, Fe and Cu were determined by ICP-AES; Rb, Mo, Ba, Sr, Ni, Cd, Cs, Pb, Al, Cr and Co were determined by ICP-HRMS. Using the analytical results of 13 elements (P, K, Mg, Ca, Mn, Zn, Fe, Cu, Rb, Mo, Ba, Sr, Ni), brown-rice samples were analyzed using chemometrics software, including cluster analysis and principal component analysis (PCA), to categorized into particular groups. As a result, cluster analysis (Ward method) and PCA using 9 elements (Mn, Zn, Fe, Cu, Rb, Mo, Ba, Sr, Ni) could distinguish rice samples cultivated in the Tohoku/Kanto area from those in Hokuriku, and those in Tohoku from those in Kanto.
Keywords : brown-rice; cluster analysis; principal component analysis; geographic origin; trace-element composition.
Minako Hada, Masahiko Takino and Shigeki Daishima*
*Yokogawa Analytical Systems Inc., 3-3-11, Niitaka, Yodogawa-ku, Osaka 532-0033
(Received 13 January 2000, Accepted 20 February 2000)A method for the analysis of 7 aldehydes in drinking water and river water was developed using an headspace sampler in combination with a GC/MS with negative-ion chemical ionization (NICI). A sample (15 ml) was simply transfered to a 20 ml headspace vial, followed by the addition of a 0.1% O-(pentafluorobenzyl) hydroxylamine (PFBOA) solution (1 ml) and NaCl (2 g), in which aldehydes were converted to their O-(pentafluorobenzyl) oximes with PFBOA within two hours. A sample was put in the headspace sampler, which was set to heat at 80°C for 20 min. The gas of PFBOA derivatives was then injected into the GC/NICI-MS with methane as the reagent gas by high-pressure pulsed split injection. The detection limits of the 7 aldehydes ranged from 3.7 pg/ml to 15.3 pg/ml. The overall recoveries of the aldehydes in drinking water and river water samples were from 82% to 103% {RSD (n=5) were from 3.4% to 7.1%} and from 89% to 95% {RSD (n=5 were from 3.2% to 6.5%)}, respectively.
Keywords : aldehydes; headspace sampler; GC/MS; negative-ion chemical-ionization; pentafluorohydroxylamine; drinking water; river water.
Etsu Yamada*, Hideyuki Okita, Takeshi Yamada**, Munekatsu Hirano and Sadao Narita***
*Department of Chemistry and Materials Technology, Kyoto Institute of Technology, Sakyo, Kyoto 606-8585
**Department of Polymer Science, Kyoto Institute of Technology, Sakyo, Kyoto 606-8585
***Seiken Co. Ltd., 92-1, Shimotoba, Fushimi, Kyoto 612-8474
Because silver ion can kill bacteria in trace concentrations, such as 10 µg l-1(10 ppb), the use of silver as an antibacterial reagent has expanded in pools and spring water instead of chlorine. Although there is no regulation of silver ion in Japan, silver ion should be used in appropriate concentrations. Thus, a sensitive, easy and rapid determination of silver ion at ppb level is desired. In this work, a catalytic determination of trace silver ion on the persulfate oxidation of manganous ion to permanganate was developed and applied to the determination of silver ion in tap-water and spring-water samples. The determination limit of silver ion was 1 ppb and the relative standard deviation was 0.9% for 80 ng of silver with 5 measurements. Common co-existing ions did not interfere with the silver determination. Furthermore, the determination limit of silver ion was 2 ppb by the simple method to determine the silver concentration with the standard color table.
Keywords : trace silver ion; catalytic determination; spring water; tap water; sterilizing power.
Takashi Korenaga, Tamao Odake, Yasunari Ono and Long Rong*
*Department of Ecosystem Engineering, Graduate School of Engineering, University of Tokushima, 2-1, Minami-Josanjima, Tokushima 770-8506
(Received 17 January 2000, Accepted 19 April 2000)The possibility of a micro-total analysis system (µ-TAS) for high-speed, convenient and efficient analytical measurements has been suggested in recent years. Its application in the monitoring of human health related to environmental species has become a worldwide issue. We have developed a measurement method with a microchip-based simple sampling procedure that obeys Fick's and Henry's laws. It is suitable for measuring trace amounts of air pollutants and for monitoring and evaluating the living environment. The absorption solution, composed of 3% triethanolamine (TEA) solution, was used as an absorption solution and flowed into the fabricated microchip. Gaseous NO2, which dispersed through the porous glass material, was absorbed into the absorption solution. The influences of the flow rate of the absorption solution (0.2~0.6 ml/h) and the wind speed (0~2.5 m/s) inside a wind tunnel were studied under a NO2 concentration range of 10~150 ppb. It was shown that the concentration of NO2 in a sampling solution under a wind speed of 2.5 m/s was 20-times larger than that under a wind speed of 0 m/s when the concentration of NO2 inside the wind tunnel was fixed at 50 ppb. This sampling method was proved to be suitable for measuring of atmospheric NO2, and may also be used for sampling and evaluating the indoor environmental NO2 level.
Keywords : µTAS; microchip; porous glass; nitrogen dioxide; triethanolamine.
Makoto Sato, Jun Matsuda*, Harunobu Murayama, Ryong-Woon Shin**, Emiko Kaneko and Takao Yotsuyanagi***
*Sagamihara R & D Center, Shino-Tset Corporation, 2-29-14, Oonodai, Sagamihara-shi, Kanagawa 229-0011
**Department of Neurological Science, School of Medicine, Tohoku University 2-1 Seiryo-machi, Sendai 980-8575
***Department of Applied Chemistry, Graduate School of Engineering, Tohoku University, Aoba-ku, Sendai 980-8579
The development of a simple and sensitive method for the determination of aluminium is a subject of growing interest. The objective of this study was to apply kinetic-differentiation mode HPLC with 8-quinolinol to biological and water samples. The aluminium chelate is detected fluorometrically at Ex 370 nm and Em 504 nm. The most remarkable point of the proposed method is that only aluminium ion respond selectively among many metal ions in the sample matrix. The limit of detection, 1 µg/l, is approximately ten-times higher than that of graphite-furnace AAS, which is currently used in routine work. Precautions to prevent aluminium contamination during sample preparation are described. The proposed method has been successfully applied to serum, urine, tap water, and bottled mineral water. The most important practical application is in the treatment of patients on dialysis for whom aluminium accumulation can present serious problems. A comparison of the aluminium concentration between healthy subjects and subjects on dialysis has been difficult because the concentrations in the former group approach the lower limit of those detectable by conventional methods. Using the proposed HPLC, it was determined that the average aluminium concentration in serum was 3 µg/l for 240 healthy subjects, and 11 µg/l for 196 patients on dialysis.
Keywords : aluminium; kinetic-differentiation mode HPLC; serum; urine; cerebrospinal fluid; drinking water; 8-quinolinol.
Takeshi Tsunesada, Atsuhiko Takehara, Kazuta Mitsuishi* and Toshihide Ihara**
*Industrial Technology Center of Okayama Prefecture, 5301, Haga, Okayama 701-1296
**National Institute of Materials and Chemical Research, 1-1, Higashi, Tsukuba-shi, Ibaraki 305-8565
(Received 14 January 2000, Accepted 21 February 2000)
Saccharide and sugar alcohol were analyzed by pyrolysis GC/MS. In this experiment, an excess of tetramethylammonium hydroxide was added to saccharide and a sugar alcohol solution. Reducing sugar was different from sugar alcohol and nonreducing sugar in the analysis results. Sugar alcohol was derivatived without pyrolysis. D-glucitol, D-mannitol, and galactitol were analyzed simultaneously with the pyrolyzer temperature at 150°C. Other sugar alcohol and nonreducing sugar, such as sucrose, were methylated without pyrolysis in the pyrolyzer. Meanwhile, some products were detected by methylation with pyrolysis from monosaccharide, such as D-glucose. Some products were detected by decomposition of the reducing sugar residue from a reducing oligosaccharide, such as maltose. This method enabled an analysis of constituent monosaccharides by pyrolysis in a pyrolyzer for reducing oligosaccharide samples, and methylation in a pyrolyzer for nonreducing sugar and sugar alcohol samples.
Keywords : pyrolysis GC/MS; tetramethylammonium hydroxide; oligosaccharide; sugar alcohol.Takashi Yamamoto and Akio Yasuhara*
*National Institute for Environmental Studies, 16-2, Onogawa, Tsukuba-shi, Ibaraki 305-0053
(Received 11 January 2000, Accepted 7 February 2000)Bisphenol A migration from polyvinyl chloride (PVC)hose to water was quantified. Pure water was poured into nine bent PVC hoses and then retained for 24 hours at room temperature. The water samples were extracted with dichloromethane. The extracts were concentrated and derivatized with N,O-bis (trimethylsilyl)trifluoroacetamide. The derivatized samples were determined by GC/MS. Bisphenol A was detected from all samples. The migration levels of bisphenol A from PVC hoses ranged from 4.0 to 1730 µg/l. The detection limit was 0.03 µg/l. These migration levels were much higher than the migration levels from polycarbonate foodstuffs. To confirm the relation between the migration period and the levels, migration tests in which the migration period was changed from 0 to 24 hours were carried out. The migration level of bisphenol A rose from 8.7 to 558 µg/l with the migration period. Since the water which passed through a PVC hose was contaminated with bisphenol A at ppb level, PVC hose might be a significant source of environmental bisphenol A.
Keywords : bisphenol A; polyvinyl chloride hose; migration.
Yuko Nishimoto, Takeshi Takenouchi, Tomoko Daigo*, Tetsuzann Nakada and Hidenobu Kuroyama**
*Faculty of Science, Kanagawa University, 2946, Tsuchiya, Hiratsuka-shi, Kanagawa 259-1293
**JDC Corporation, 4036-1, Nakatsu, Aikawa-machi, Aikou-gun, Kanagawa 254-0303
It is important to use building materials in which the inclusion of volatile organic compounds (VOC) is small, so as to prevent the sick building syndrome or the sick house syndrome. Recently, the use of wood materials as building materials has been considered to be useful because the amount of the evolution of formaldehyde from the building materials was small. However, the total amount of evolution of VOCs from wood materials was expected not to be very small. A rapid measuring method of VOCs in wood materials was developed using thermogravimetry and gas chromatography. It takes 2 hours to estimate the species and the amounts of the evolution of VOCs from wood materials. The method was as follows. First, 2 g of wood powder was sealed in a 20 ml vial, and kept at 393 K for 1 hour, 2 ml of the gas phase in this vial was then measured by GC. It was found that the sum of the peak areas from 3 min to 22 min in the chromatogram is related to the amount of evolution of VOCs from each wood material. This method proved to be an effective acceleration test to estimate VOCs in wood materials from simultaneous measurements of thermogravimetry and infrared spectroscopy. This method was applicable to some wallpapers and plasterboards.
Keywords : volatile organic compound; building materials; volatile organic compound of wood materials; rapid measuring method of volatile organic compound; GC.
Norio Teshima, Tadao Sakai*, Seiji Yasuda** and Keiro Higuchi***
E*Department of Applied Chemistry, Aichi Institute of Technology, 1247, Yachigusa, Yakusa-cho, Toyota-shi, Aichi 470-0392
**Tokai Technology Center, 2-710, Inokoishi, Meitoh-ku, Nagoya 465-0021
***FIA Division, Tokyo Kasei Kogyo Co.Ltd., 6-15-9, Toshima, Kita-ku, Tokyo 114-0003
Flow injection analysis (FIA) was applied to the simultaneous determination of nitrogen monoxide (NO), nitrogen dioxide (NO2) and sulfur dioxide (SO2) as air pollutants collected by using a passive sampling device. NO and NO2 were determined based on a diazotization/coupling reaction with a copperized cadmium (Cd/Cu) reduction column installed in the FIA system. A NOx (NO+NO2) collection filter was coated with PTIO (2-phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl), which oxidized NO to NO2, together with triethanolamine for collecting NO2. However, the residual PTIO that coexisted in the extract for a FIA measurement interfered with the diazotization/coupling reaction. We found that the interference of the residual PTIO can be completely removed by using an on-line Cd/Cu column in the FIA system. An FIA method using dimethylsulfonazo III-barium chelate was used for SO2 determination. By using these FIA systems, NO, NO2, NOx and SO2 in air samples collected at Nagoya and its environs were monitored, and the relation between the results and the weather conditions was considered. On the other hand, the same proposed FIA methods were applied to monitoring the concentrations of nitrite nitrogen and nitrate nitrogen in river water, pond water, rainwater and seawater, and of sulfate ion in seawater. The proposed FIA systems provide simple and rapid methods with high precision for the determinations of nitrogen oxides and sulfur oxides, and are thus useful for investigating the movement of these pollutants in air and water samples.
Keywords : nitrogen oxides; sulfur oxides; air pollutants analyses; water analyses; FIA.
Tomoyuki Chimuro*,***, Tamizi Sugiyama* and Ryuhei Funabiki**
*Department of Agricultural Chemistry, Meiji University, 1-1-1, Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571
**Department of Applied Biological Science, Tokyo University of Agriculture and Technology, 3-5-8, Saiwai-cho, Fuchu-shi, Tokyo 183-8509
***Present address; Isehara Research Laboratories, Kanto Chemical Co., Inc., 21, Isehara-shi, Kanagawa 259-1146
Mass spectrometry using deuterium-labeled standard was applied to determine thymine glycol in the urine of rats fed with catechin and rutin in order to evaluate their antioxidative efficacy. The rats were freely fed a 20% casein diet containing 1% catechin and/or 1% rutin and water for 56 days. The urine samples were collected on the last 2 days of feeding. Thymine glycol-d3 was added to one ml aliquots of the urine samples, and then recovered with thymine glycol in the samples by affinity chromatography, solid-phase extraction and HPLC using an ODS column. The recovery of thymine glycol was 40-56% through the purification steps. The thymine glycol fractions recovered were converted to tetra-TMS derivatives and then applied to GC/MS analysis. Thymine glycol in urine samples of rats fed with catechin decreased to 68% levels (P<0.05) of those of no-administered control. However, the antioxidative efficacy of rutin was not observed by this method.These results suggest that catechin has the ability to prevent oxidative DNA damage on the basis of thymine glycol levels in rat urine samples.
Keywords : thymine glycol; urine; GS/MS; isotope dilution; catechin.
Takashi Korenaga, Momoko Kumemura, Murad I. H. Helaleh, Chiharu Hara* and Takao Yamauchi**
*Faculty if Integrated Arts and Science, University of Tokushima, 1-1, Minamijosanjima-cho, Tokushima 770-8502
**Graduate School of Engineering, University of Tokushima, 2-1, Minamijosanjima-cho, Tokushima 770-8506
The droplet method is known to be one of the gas passive sampling monitoring procedures. A liquid droplet containing a reagent solution (boric acid and hydralazine) is formed at an end of a stainless-steel pipe. Formaldehyde gas in ambient air is absorbed into a growing droplet interface. After gas-trapping process, gas-collected droplets in a vial are analyzed by spectrofluorometry at 389 nm after boiling for 25 minutes. In this work, three diameter sizes of the pipe, the flow rate of the reagent solution and the boiling time needed for a reaction between formaldehyde and hydralazine were examined. The detection limit and coefficient of variation for formaldehyde were 2.0 ppb and 5~16% in ambient air, respectively. This droplet method was applicable to the measurement of formaldehyde in actual indoor air samples with satisfactory results.
Keywords : droplet method; passive sampling; formaldehyde; indoor air; gas absorption.
Sahori Takeda*, Shigeo Iida, Kenji Chayama, Haruo Tsuji**, Keiichi Fukukshi***, Masataka Yamane, Zyun Siroma and Shin-ichi Wakida*
*Department of Energy and the Environment, Osaka National Research Institute, AIST, 1-8-31, Midorigaoka, Ikeda-shi, Osaka 563-8577
**Faculty of Science, Konan University, 8-9-1, Okamoto, Higashinada-ku, Kobe 658-8501
***Cargo Transportation Research Institute, Kobe University of Mercantile Marine, 5-1-1, Fukaeminamimachi, Higashinada-ku, Kobe 658-0022
The simultaneous separation of chlorinated phenols including structural isomers by capillary electrophoresis was studied. Structural isomers of mono- and dichlorophenols and phenol were selected as analytes because of their low hydrophobicity. In order to detect them using mass spectrometry in the future, three volatile running solution (ammonium acetate, ammonium hydrogencarbonate and ammonium carbonate) were investigated. The migration behavior of analytes was found to be governed by their dissosiation constants. When an ammonium hydrogencarbonate solution (pH 8.1) was used, the peak shapes were the best, and all dichlorophenol isomers completely separated. The optimized concentration of the solution was 20 mM. All analytes were completely separated within 8 minutes.
Keywords : capillary electrophoresis; chlorinated phenols; separation of structural isomers; volatile running solution.
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