Vol. 50 No. 5
May, 2001
Makoto Ueki*
*Doping Control Laboratory, Mitsubishi Kagaku Bio-Clinical Laboratories, Inc., 3-30-1, Shimura, Itabashi-ku, Tokyo 174-8555
(Received 5 February 2001)Doping control is conducted at national and international sports events using cutting-edge analytical techniques. Most problematic doping agents used by athletes to enhance performance are a series of anabolic androgenic steroids, so called `muscle-enhancing drugs'. Some 37.1% out of 2,624 positive doping cases in 1999 proved to be due to the use of anabolic steroids according to laboratory statistics reported by the medical commission of the International Olympic Committee. Although the majority of the detected doping agents are synthetic anabolic steroids which do not exist in nature, doping cases with naturally occurring anabolic androgenic steroids are also increasing. Because most anabolic steroids are extensively metabolized in the human body and excreted into the urine very rapidly, the parent drug is not detectable within a few days after administration. Thus, the detectability of doping depends on selecting of the analyte, the target compound to be monitored, and the sensitivity method used. For naturally occurring hormones, positive test results have to be supported by additional scientific evidence that shows the heterogeneity of the origin of the target compounds. One example of such strategies is an indirect statistical evaluation by comparing the analysis results with those obtained from non-doping subjects. We developed a carbon isotope methodology for differentiation between exogenous and endogenous compounds, which was applied for the first time in Olympic history in 1998 to detect doping with naturally occurring testosterone-related steroids. The source of human physiological steroids is a mixture of food cholesterol from meat, fish, poultry etc., but commercially available steroids are usually synthesized from phytosterols which exist in C3-plants having a lower 13C-content than animal sterols. The present status of comprehensive screening of steroids, and the latest strategy to enhance both the sensitivity and specificity of the testing system, are discussed in this report.
Keywords : anabolic steroids; doping; carbon isotope ratio; testosterone; GH doping.
Takashi Ito*
*Department of Chemistry, Science University of Tokyo, 1-3, Kagurazaka, Shinjuku-ku, Tokyo 162-8601
(Received 25 January 2001, Accepted 19 March 2001)The uphill transport of lanthanoid (III) ions (Ln3+; La3+, Pr3+, Nd3+, Eu3+, Er3+ and Lu3+) was performed with supported liquid membranes (SLMs) containing n-decane solutions of 1,1,1,2,2,3,3-heptafluoro-7,7-dimethyl-4,6-octanedione (FOD) in the presence and absence of tri-n-octylphosphine oxide (TOPO) or 4,4'-dioctadecyl-2,2'-dipyridyl (DODpy). In all of the SLMs examined, the proton-driven uphill transport of Ln3+ was observed, as indicated by a decrease in the pH of the outer (feed) solutions after the transport of Ln3+ from the outer (originally, pH 3.5, 4.5 or 5.5) to inner (receiving) solutions (pH 1) as well as a coincidence of the concentrating factors observed for Ln3+ with those calculated from a theoretical model for uphill transport through an SLM. Both an increase in the initial pH of the outer solution and the addition of Lewis bases into SLMs result in an enhancement of the transport rate of Ln3+ on one hand and a deterioration of the separation among Ln3+ on the other hand. Interestingly, the separation selectivity between the lighter and heavier lanthanoid ions was better for SLMs containing DODpy than for those containing TOPO. An enhancement of the transport rate as well as the separation selectivity reflect adduct formation between tris(β-diketonato)lanthanoid and the Lewis bases.
Keywords : supported liquid membranes (SLMs); proton-driven uphill transport; lanthanoid ions; adduct formation; β-diketone.
Masahiko Takino*, Shigeki Daishima, Kenji Yamaguchi** and Taketoshi Nakahara***
*Yokogawa Analytical Systems Inc., Kansai brunch office, 3-3-11, Niitaka, Yodogawa-ku, Osaka 532-0033
**Yokogawa Analytical Systems Inc., Application center, 2-11-13, Nakamachi, Musashino-shi, Tokyo 103-0006
***Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1, Gakuen-cho, Sakai-shi, Osaka 599-8531
An analytical method for the determination of twelve pesticides in river water with liquid chromatography/mass spectrometry (LC/MS) has been developed. Under reversed-phase liquid-chromatographic conditions, twelve pesticides were analyzed using electrospray ionization(ESI) with a simultaneous acquisition of positive ions and negative ions. The effects of the liquid-chromatographic mobile phase on the separation of pesticides, the fragmentor voltage and the capillary voltage with ESI on the sensitivity of pesticides were examined. The maximum sensitivities for all pesticides in simultaneous acquisition were accomplished by setting the capillary voltage at 2500 V. Large volumes of river-water samples were directly injected into the precolumn, and then twelve pesticides were separated by an analytical column with a column-switching technique. The limit of detection (LOD) of these pesticides ranged from 0.7 to 2.1 pg/ml. The overall recoveries of pesticides were from 83.4 to 109.4% {RSD(n=5) were from 1.1 to 7.2%} for drinking water.
Keywords : LC/electrospray ionization MS; column switching; peticides; large volume injection; simultaneous acquisition.
Ikuko Ishii-Karakasa*
*Department of Biochemistry, School of Medicine, Kitasato University, 1-15-1, Kitasato, Sagamihara-shi, Kanagawa 228-8555
(Received 16 January 2001, Accepted 26 February 2001)Measurements of the 600 MHz 1D 1H-NMR and H-H COSY spectra are possible at the nanomole order of oligosaccharide. However, many proton peaks of oligosaccharide are observed to overlap at near δ 2~4 ppm in the 1H-NMR spectrum. Therefore, full assignments of the 1H-NMR spectrum of oligosaccharide are difficult from only the 1D 1H-NMR and H-H COSY spectral data. However an analysis of the 1H-NMR spectrum of the oligosaccharide is possible using the following three conditions: 1. The splitting pattern of the AMX type is symmetric at the chemical shift. 2. The multiplicity of protons included in overlapped peaks is from the triplet to the octet (dd-ddd). 3. In the oligosaccharide, the conformations of composite monosaccharides are similar to those of the corresponding monosaccharide derivatives. The program (FORTRAN 77) for an analysis under this condition was developed, and was applied to analyses of pyridylaminated-disaccharide (Galβ1-3GalNAc-PA) and disaccharide-alditol (Galβ1-3GalNAc-ol).
Keywords : oligosaccharide; nanomole order analysis; 1D 1H-NMR; H-H COSY; full-assignment.
Michio Zenki, Shuhei Tanaka and Yuko Iwadou*
*Department of Chemistry, Faculty of Science, Okayama University of Science, 1-1, Ridai-cho, Okayama 700-0005
(Received 15 January 2001, Accepted 3 March 2001)The use of a closed-loop flow system in flow injection analysis (FIA) allows the recycling of any reagents which are present in excess. The spectrophotometric determination of iron(II) with 1,10-phenanthroline was chosen as a model system. The reagent solution was circulated through a photometric cell at a flow rate 1.5 ml/min, and signals at 510 nm were recorded on a strip chart recorder. To estimate the recycling of the reagent solution, Fe(II) standard solutions (0~10 ppm) were injected in triplicate for calibration, a 5 ppm Fe(II) standard solution was injected 100 times in sequence, and calibration followed again. The effect of the reservoir mixture volume, the concentration of the Fe(II) standard solution and 1,10-phenanthoroline, and the injection volume were investigated. The typical reservoir mixture, which consisted of 0.1% o-phen and ascorbic acid and 0.02 M acetate buffer (pH 5.0), allowed consecutive determinations of 5 ppm Fe(II) more than 100 times.
Keywords : cyclic-FIA; Fe(II)-1,10-phenanthroline; repeated use of a reagent solution.
Yasuhiro Suzuki, Masaaki Kasamatsu, Shinichi Suzuki*, Kazuo Ohashi and Akira Kawase**
*National Research Institute of Police Science, 6-3-1, Kashiwanoha, Kashiwa-shi, Chiba 277-0882
**Seiko Insturuments Inc., 1-8, Nakase, Mihama-ku, Chiba 261-8507
The application of inductively coupled plasma atomic emission spectrometry (ICP-AES) to the determination of trace impurities in arsenous acid was examined in order to discriminate arsenous acid samples from different origins. About 250 mg of a sample was accurately weighed and put into a glass beaker; 5 ml of HCl and 0.5 ml of HNO3 were then added. The beaker was capped with a watch glass and heated on a hot plate until the sample was completely dissolved. After cooling to room temperature, the sample solution was transferred to a volumetric flask, followed by dilution to 25 ml with purified water. Five elements (Se, Sn, Sb, Pb and Bi) could be determined with RSDs between 0.9% and 5.5% at levels of 120 and 15 µg/g, respectively. The effect of the arsenic matrix and reagents on the background levels and the emission intensities of these elements could be compensated by using standard solutions containing the same amount of acids as the sample solutions, and by adopting a spectroscopic background correction. The obtained values for Sb and Pb were in good agreement with those by the JIS method. The proposed method was applied to 14 kinds of arsenous acid samples from different sources. A comparison of the analytical results made it possible to distinguish 14 samples from each other, except for only 4 pairs.
Keywords : analysis of trace elements; arsenous acid; ICP-AES; forensic science.
Yoshiaki Minamiya, Isoshi Nukatsuka and Kunio Ohzeki*
*Department of Materials Science and Technology, Faculty of Science and Technology, Hirosaki University, Hirosaki-shi, Aomori 036-8561
(Received 9 January 2001, Accepted 5 March 2001)A simple, rapid and highly sensitive method was developed for the determination of trace amounts of ammonia. The method is based on the following steps: (1) ammonia is oxidized to nitrite ion with sodium hypochlorite in the presence of potassium bromide in an alkaline media; (2) the effect of remaining hypochlorite is masked by the addition of acetone; (3) the ion is reacted with sulfanilamide and N-1-naphthylethylenediamine in an acidic media; (4) the resulting reddish-purple compound is concentrated and fixed on a finely ground cation-exchange resin by batch operation; (5) the resin particles are filtered through a membrane filter in the presence of Zephiramine, leaving a colored thin-layer disc on the filter; and (6) the absorbance of this thin layer is measured directly with a spectrophotometer (545 nm). A calibration graph of good linearity was obtained up to 1.0 mg ammonia in a 10 ml of sample solution when the resin phase absorbance was measured against a resin thin layer, while linearity up to 0.8 mg of ammonia was obtained when the resin-phase absorbance was measured against a membrane filter. The detection limit was 5.3 ng (n=5) and 24.0 ng (n=5) in a 10 ml sample solution, respectively. The proposed method was applied to the determination of ammonia in a river-water sample. Recoveries of 93.6~107% were obtained.
Keywords : ammonia determination; spectrophotometry; ion-exchange resin thin layer.
Michio Zenki, Tadashi Yoshida, Mikoto Ohiwane and Miki Nakamura*
*Department of Chemistry, Faculty of Science, Okayama University of Science, 1-1, Ridai-cho, Okayama 700-0005
(Received 7 February 2001, Accepted 19 March 2001)A simple solid-phase colorimetry for the determination of alkylbenzenesulfonate (ABS) has been proposed. Methylene Blue (MB) reacts with ABS to produce an ion-associate, which is adsorbed onto a flexible polyurethane foam (PUF, polyether type; density, 20 kg/m3; hardness, 11.5 kgf). The color intensity of the foam-adsorbed MB-ABS complex was proportional to the ABS concentration, and thus the concentration of ABS could be determined by both visual and tristimulus methods. The recommended procedure is as follows. Five ml of 1M acetate buffer solution (pH 5.0) and 10 ml of 1.0×10-3 M MB were added to a 200 ml sample solution containing less than 0.8 ppm of ABS. A chip of PUF (2×2×2 cm) was put into the solution and stirred with a magnetic stirrer for 15 minutes. The chip taken up from the solution was rinsed with distilled water to remove any excess MB. The color intensity was measured by tristimulus colorimetry with a calibration curve, together with a visual measurement, followed by the standard series method. The proposed methods were applied to the determination of ABS in pond and river-water samples.
Keywords : alkylbenzenesulfonate; Methylene Blue; polyurethane foam; solid-phase preconcentration of anionic surfactant; tristimulus colorimetry.
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