Detection and quantitative determination of the components : i) radical species, ii) hydroperoxides, iii) secondary aldehydes, hydrocarbons and fatty acids, and iv) reaction products between proteins, which are generated during lipid peroxidation, are reviewed. Determination of plural classes of components is required for the accurate monitoring of lipid peroxidation. Among the many known assay methods, thiobarbituric acid test can be properly used for the monitoring of lipid peroxidation. The principles of the test, which has been recently clarified, is reviewed in detail.

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Aqueous alkylphenol solutions were treated with chlorine at 20°C under various experimental conditions. Changes in the compositions of the chlorination products in water were determined by gas chromatographic (GC) and GC-mass spectrometric (GC-MS) analyses of diethyl ether extracts. Alkylphenols were shown to produce a variety of chlorinated compounds, including alkylpolychlorinated phenoxyphenols (predioxins), having one to five chlorine atoms, as by-products in chlorine-treated water. Production of some of these predioxins is dependent on the number of equivalents of chlorine per mol of compound and on the reaction pH. These results suggest that chlorine treatment of water contaminated with alkylphenols leads to the production of predioxins, which are precursors of the highly toxic chlorinated dibenzo-p-dioxins.

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For the investigation of the contamination mechanism of underground water with 1, 1, 1-trichloroethane (MC), trichloroethylene (TCE), tetrachloroethylene (PCE) and carbontetrachloride (CTC), it is necessary to determine them in the soil. Since these compounds are volatile, sample storage is difficult. Moreover, it is difficult to extract them, which were strongly adsorbed on the soil, with nonpolar organic solvents. An attempt was made to use the 100 ml vial with a metal sealed cap, as storage and extraction bottles, and the determination of the above contaminants were performed by the water-hexane extraction method. Soil samples were examined by this method according to the following procedures ; About 5 g of soil samples was weighed in the field. The sample was poured immediately into the vial, which had been added with about 40 ml of purified water beforehand. Then, more water was added to the level mark of 80 ml. The vial was sealed with a PTFE seal, silicone rubber septum and aluminum crimp cap. The vial was shaken for 15 min and kept at 5°C until use. For the examination, the cap of vial was opened, and 20 ml of n-hexane was added to the vial. After the top was sealed again, the vial was shaken vigorously in lateral direction for 30 min. The hexane extract was injected into a ECD-GC. CV in repeated examinations was within 10% and reproducibility was supported. As the results of trials, the use of vials for storage and extraction was indicated to be a simple, practical and satisfactory method.

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Concentrations of six volatile aromatic hydrocarbons (VAHs), i.e. benzene, toluene, ethylbenzene and three kinds of xylene, in the ambient air at the rural, suburban and urban sites were monitored. Twenty-four h measurements of VAHs were carried out during 8 consecutive days in June, August, October and December, 1991, and in February and April, 1992. Mean concentrations at all sites of benzene, toluene, ethylbenzene, o-xylene, m-xylene and p-xylene were 1.7 ppb, 2.3 ppb, 0.39 ppb, 0.29 ppb, 0.70 ppb and 0.29 ppb, respectively. Concentrations of all VAHs were most elevated at the urban site compared with those at the rural and suburban sites. The VAH concentrations decreased on Sunday ; the relative ratios of VAH to benzene in air at the investigated sites were similar to those in exhaust gas from vehicles and to those in air from automobile tunnels. These facts suggest that the VAHs in these sites are mainly originated from vehicle emissions and also suggest that the VAH concentrations reflect traffic of each area. An excursion in toluene measured at the suburban site was related to the usage of solvent for painting. All the VAH concentrations were higher in winter season than in summer season. This seems to be caused by meteorological factors. Cancer risk calculations for inhalation of benzene in the ambient air were from 30×10^-6 (rural) to 70×10^-6 (urban).

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Effects of rare earth elements (REEs) on the time courses of REE, Ca, Mg and P concentrations in the liver, kidney, spleen, lung, femur and whole blood were investigated in the male rats of Wistar strain. Four kinds of REE salts, i.e. dysprosium chloride (DyCl₃), europium chloride (EuCl₃), ytterbium chloride (YbCl₃) and yttrium chloride (YCl₃)], were administered intravenously from the caudal vein (10 mg/kg as REE). Contents of REE, Ca, Mg and P were estimated by the wet digestion-ICP-AES method as a function of time. Results were as follows : 1) Concentrations of Ca in the liver, spleen and lung increased extremely in the rat administered with YCl₃. Pattern of hepatic Ca concentration as a function of time was similar to that of hepatic Y concentration, and Ca concentration was not significantly different from the control group at 45th d after the administration. Patterns of Ca concentrations were different from Y in the spleen and lung. REEs administration did not affect significantly the concentrations of Ca, Mg and P in the liver, kidney, spleen and lung except the concentrations of Ca in the liver, spleen and lung of Y-administered rats. 2) Concentrations of Ca, Mg and P in the whole blood of REE-administered rats varied from the control group within 1 d after the administration. 3) No significant effects were observed in the femoral Ca, Mg and P concentrations. 4) Concentrations of REEs in the whole blood and liver decreased exponentially in the ranges of 15 min-1 d and 1-45 d (8 h-45 d in case of YCl₃-administered rats) respectively. The half lives of Dy, Eu, Yb and Y were calculated as 6.94, 6.78, 6.84 and 0.427 h for the whole blood, and 16.2, 21.0, 15.5 and 19.3 d for the liver, respectively.

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Scavenged effects of Cu (II) chelates of imidazole and thiazole derivatives on superoxide (SO), H₂O₂ and OH radical were studied and compared with that of cimetidine, which is well known as a superoxide scavenger, and with those of superoxide dismutase (SOD), catalase and Cu (ClO₄)₂. Six of imidazole and 6 of thiazole derivatives were cimetidine and famotidine analogues, respectively. Superoxide scavenged effects (IC₅₀) of Cu (II) chelates were in the range of 0.48-5.67μM determined by the nitroblue tetrazolium method in a phenazine methosulfate-NADH system (method A) and in a xanthineoxidase-hypoxanthine system (method B), whereas the IC₅₀ values of SOD were 4.5×10^-2 and 3.4×10^-2μM by the methods of A and B, respectively. No catalase activity of Cu (II) chelates were observed. In the studies of the scavenged effect of Cu (II) chelates on hydroxyl radical, IC₅₀ values of Cu (II) chelates of N-methyl-N'-[2-(imidazol-4-yl) methylthioethyl]-thiourea (I-1) and its 5-methylimidazole derivative (I-2), which possessed methylthiourea groups, were 13.7 and 8.0μM, respectively, and the Cu chelate of I-2 had the highest scavenged activity against hydroxyl radical generated from Fenton reaction.

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The efficiency of removing chloroform and carbon tetrachloride from chemical wastewater by a water treatment plant using activated carbon adsorption and coagulation precipitation processes was investigated. The results showed that the treatment removed the two compounds with a respective average efficiency of 82.3% and 84.7%. Both coagulation precipitation and activated carbon adsorption processes showed effective removal results.

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Distribution of free and conjugated 3-tert-butyl 4-hydroxyanisol (BHA) in liver and serum of dams and in the fetus was analyzed by HPLC with electrochemical detection after 0, 200, 400, and 800 mg/kg body weight of BHA was administered orally to pregnent rats. BHA was detected in fetus of all BHA-administered rats though its concentration in fetus was much lower than that in liver and serum. The ratio of total BHA (free BHA plus conjugated BHA) to free BHA was approximately constant in liver, serum and fetus irrespective of BHA concentration administered.

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The determination of aspartame in carbonated beverages was investigated by enzymatic method. Conditions for determining aspartame were as follows : time of hydrolysis by 6 N HCl, 5 h at 110°C ; concentration and pH of 2-amino-2-methyl-1, 3-propanediol-HCl buffer, 200 mM and 7.5 ; reaction temperature, 37°C ; reaction time, 5 h ; GOT, 0.655 IU/ml ; MDH, 0.234 IU/ml ; α-ketoglutarate ; 0.615 mM ; concentration of NADH, 0.1 mM. The method gave high recoveries (93.9-102.1%) of aspartame to amount added (0.058-0.339 mg/ml) into carbonated beverages. The minimum limit of determination was 6μg/ml.

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We investigated the effect of vitamin E on active oxygen generation by alveolar macrophages (AMs) challenged with different stimuli to determine the influence of the vitamin. AMs were obtained from rats orally treated with vitamin E (100 mg/kg or 150 mg/kg) for 6 d, and Concanavalin A (Con A) and 12-o-tetradecanoylphorbol-13-acetate (TPA) were used as stimuli. AMs from the vitamin E-treated group showed a dose-dependent increase of active oxygen generation when stimulated with Con A. while a dose-dependent decrease of production by AMs challenged with TPA was observed with the vitamin treatment. These results suggest that vitamin E has a modulating effect on active oxygen production by AMs stimulated with stimuli.

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