Degradation effects of bis (methylmercuric) selenide (BMS) by the protein-SH and reduced glutathione in the liver and brain homogenates of non-treated rats were investigated in the reaction system consisting of the liver homogenate of selenite-treated rat and methylmercury. The protein-SH in the liver and brain homogenates was found to be able to decompose BMS. However, it was revealed that the reduced glutathione in the liver and brain homogenates was independent of the degradation of BMS. The degradation ability of the protein-SH of the liver homogenate was approximately the same as that of the protein-SH of the brain homogenate. On the other hand, when methylmercury was added to the liver homogenate mixture from selenite-treated and non-treated rats or when BMS formed in the mixture of the liver homogenate from selenite-treated rat and methylmercury was decomposed by the addition of the liver homogenate of non-treated rat, an approximately equal amount of BMS was found. The same result was observed when the brain homogenate was used instead of the liver homogenate. These results indicate that the formation and degradation of BMS repeatedly occur in the mixture of the liver homogenate of selenite-treated rat and the liver or brain homogenate of non-treated rat added with methylmercury.

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The objective of this study was to investigate the relation of formation of non-volatile amines to spoilage of sea foods. The amounts of six non-volatile amines, histamine (His.), cadaverine (Cad.), putrescine (Put.), spermidine (Spd.), tyramine (Tyr.) and agmatine (Agm.), formed during the putrefaction were investigated, by using the muscle of various commercial sea foods. And then, the pH value and the volatile base nitrogen (VBN) contents were investigated simultaneously. Raw pacific mackerel, tuna, sardin, pacific saury, shortneck clam and boiled octopus were allowed to stand at the room temperature of 27±2°C. The analytical methods used for the determination involved the separation of non-volatile amines from sea foods by eluting through a cation-exchange resin column, the formation of their dansyl chloride or 4-fluoro-7-nitrobenzo-furazan (NBD-F) derivatives and the determination of these derivatives by high performance liquid chromatography with a fluorescene spectromonitor. The variation of pH value was found in various sea foods during the putrefaction. And, the development of VBN contents was found to be larger in quantity in tuna, octopus and pacific mackerel than others. On the other hand, when no detectable decomposition was observed by the determination of pH value and VBN contents, various non-volatile amines, His., Cad., Tyr. and Put. have already appeared. The formation of His. was observed as decomposition of pacific mackerel, tuna and sardine progressed. Particulary, its formation in pacific mackerel and tuna went up very rapidly to a higher level than either of the other amines. The large and rapid formation and the loss of Put. were also observed during the decomposition process in octopus. Therefore, these amines may serve as quality indicators of any sea food.

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A high performance liquid chromatographic method (HPLC) was developed for the simultaneous determination of oxytetracycline (OTC), chlortetracycline (CTC), chloramphenicol (CP), sulfamonomethoxine (SMMX), sulfadimethoxine (SDMX), furazolidone (FZ) and difurazone (DFZ) in cultured fish. The drugs were extracted from fish with 0.5% metaphosphoric acid-methanol (8 : 2), and the extract was filtered and concentrated. The concentrated solution was passed through a Sep-pak C₁₈ cartridge. The cartridge was washed with water and eluted with methanol. The eluate was evaporated to dryness, and the residue was dissolved in acetonitrile-water (3 : 7). The sample solution was analysed by HPLC using a Nucleosil 5 C₁₈ column as a column and acetonitle 0.05 M monobasic sodium phosphate (35 : 65), pH 2.5 as a mobile phase. The average recoveries of OTC, CTC, CP, SMMX, SDMX and FZ from rainbow trouts, yellowtails and red sea breams fortified at 1.0 μg/g were 68.9-91.7%. The limits of detection were 0.05 μg/g for OTC, CP, SMMX, SDMX and FZ, 0.1 μg/g for CTC and 1.0 μg/g for DFZ.

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A method was developed to directly detect glutathione S-transferase (GST) on the surface of a gel-plate after electrophoresis. First, a photograph of the background photoabsorption of the gelplate was taken by exposing photographic paper laid under the gel-plate to ultraviolet light (365 nm) without any chemical treatment of the gel surface. Next, the same plate was evenly coated with a solution consisting of 3 ml of 20 mM reduced glutathione (GSH) in water and 0.3 ml of 30 mM 1-chloro-2, 4-dinitrobenzene (CDNB) in ethanol. This plate was observed under ultraviolet light (365 nm), and photoabsorbing spots were directly photographed by the same method as before. Finally, the same plate was stained with Coomassie Brilliant Blue R-250 to give a protein picture. The mutual comparison of these three electrophoretic pictures made it possible to detect GSTs despite the presence of many other proteins on the gel-plate.

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A membrane of microporous polyethylene hollow fibers (EHF membrane) has often been used to prepare sterilized water in medical institutions. In the present investigation, we have studied the capacity of EHF membrane to adsorb mutagens from drinking water and examined some properties of the mutagens. Through the module of EHF membrane, drinking water of three cities (A, B and C) was passed and the adsorbate extracted with methanol. The methanol extract was dissolved in dimethylsulfoxide and tested for the mutagenicity to Salmonella typhimurium TA 100, TA 98 and TA 1537 with and without S9 mix. All the extracts showed mutagenic activities to these three tester strains, and it was demonstrated that the EHF membrane has a capacity to adsorb mutagens from drinking water. The mutagenic activities of the extracts decreased by the addition of S9 mix to these test systems. When the adsorption ability of EHF membrane was compared to that of the activated charcoal, the ability of the former was about 4.6 times higher than that of activated charcoal. Mutagens adsorbed of EHF membrane were soluble in most organic solvents, especially in ethyl ether. When the methanol extract was separated into acidic, basic and neutral fractions with ethyl ether, the neutral fraction showed the highest mutagenic activity. The mutagens adsorbed to EHF membrane were relatively stable to heat.

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Gel chromatography with Sephadex LH-60 has been combined with inductively coupled plasma emission spectrometry (ICP) for selective detection and determination of molecular weight of organosilicon compounds. Application of this method to the field samples and organosilicon containing products were described ; field samples were sludge from night soil treatment plant, river sediment and ash from municipal incinerator, and organosilicon containing products were anti-foaming agent, car polish and cosmetic (cologne). The organosilicon concentration ranged from 0.19 ppm to 89 ppm in field samples, and from 1300 ppm to 47000 ppm in the products. The average molecular weight of organosilicon compounds extracted from the field samples were >6000. The organosilicon compounds in incineration ash were made up of a broad molecular weight distribution, although they consisted mostly of high molecular weight compounds. The organosilicon compounds were ascertained to be polydimethylsiloxane by infrared spectroscopy. The organosilicon compounds in cosmetic (cologne) were extremely low molecular-weight compounds, and identified to be octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane.

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The metabolic fate of phosphoric acid triesters in the goldfish (Carassius auratus) were clarified through some experiments in vitro and in vivo. Tributylphosphate (TBP) was converted to dibutyl 3-hydroxybutyl phosphate (TBP-OH) and dibutyl phosphate (DBP) by incubation with goldfish liver microsomes. This reaction was Nicotinamide Adenine Dinucleotide Phosphate (Reduced form) (NADPH)-dependent and presumed to be an oxidation by mixed function oxidase (MFO). The microsomes did not metabolize tris (2-chloroethyl) phosphate, tris (1, 3-dichloro2propyl) phosphate (TDCPP), and triphenylphosphate (TPP) as well as TBP. The soluble fraction of goldfish liver contained an enzyme that acted specifically on TDCPP. The enzyme was glutathione (GSH)-dependent and had an optimum pH at 8-9, and it was concluded to be glutathione S-transferase (GSTase), which was stable at 45°C. GSTase in the goldfish had higher activity than the rat enzyme only toward TDCPP in several substrates tested. The superiority of goldfish GSTase to the rat enzyme might come from the difference of their rate constants, K_m values on TDCPP. The GSH contents in the liver and whole body of the goldfish were significantly decreased by exposure to diethyl maleate (DEM). Pretreatment with DEM increased the assumulation of TDCPP in the fish 6.6-fold but scarcely affected TBP and TPP contents. This results indicate that GSTase is concerned with in vivo metabolism of TDCPP. Killifish (Oryzias latipes) absorbed TBP from water and metabolized it to TBP-OH, butyl bis-(3-hydroxybutyl) phosphate and DBP, which are the same as the metabolites obtained with MFO in the goldfish liver.

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Wet digestion in a microwave oven was examined for rapid determination of Zn, Cu, Mn, Pb and Cd. Analytical results for metals in foods obtained by this microwave oven-digestion (MOD) method agreed well with those obtained by the conventional wet digestion technique (Kjeldahl furnace method) and further, the analytical results for National Bureau of Standards (NBS) standard reference material agreed with the certified values. The values of recovery and coefficient of variation of the metals in food samples were 84.3-113% and 0.1-6.0%, respectively. The results indicate that the MOD method could be useful for the determination of various metals in foods.

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Methamphetamine was found to form an ion-associated complex with rose bengal (RB) by shaking with 1 ml of 0.1% RB solution in the presence of bromphenol blue to prevent the interfering of RB layer. The complex was successfully extracted with dichloromethane at pH 7.3 and gave yellowish orange fluorescence under UV light. The limit of detection of methamphetamine determined by the aid of the fluorescence of the extracted layer was 0.2 μg in aq. solution and 0.6 μg in the urine. This method was applied to the screening test for urine specimens of methamphetamine-abuse suspects and satisfactory results were obtained.

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Systematic determination method for various kinds of pesticides (organochlorine, organophosphorus, carbamate, acid amide, dinitro aniline) was described. The pesticides were simultaneously extracted from sample with acetone and acetone-water (7 : 3) mixture, diluted with 10% NaCl solution, and reextracted with dichloromethane-hexane (1 : 4) mixture. The organic layer was concentrated, purified by partition between acetonitrile and hexane, fractionated by silica gel or active charcoal column chromatography, and then determined by gas chromatography with electron capture or flame thermionic detection system. Recoveries of the 8 pesticides (quintozene, chlorothalonil, disulfoton, o, o-Diisopropyl S-benzyl phosphorothioate, 3-(sec-Butyl) phenyl N-methylcarbamate, propoxur, alachlor and trifluraline) added to orange and wheat were within the range of 57.0-71.8% by the proposed method.

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The determination method of chlorite in foods, which is permitted to be used as a bleaching agent, was established by photometric ion chromatography (PIC). The PIC was performed on a conventional high-performance liquid chromatographic system including an Oyobunko ASA-4000 column and a UV detector set at 250 nm. The mobil phase was 5×10^-4M disodium phthalate-boric acid buffer solution at a flow rate of 0.8ml/min. Sample solutions prepared by aqueous extraction were treated with BOND ELUT SAX cartridge, and directly subjected to chromatography. The detection limit of chlorite was at a concentration of 5 ppm. The actual behavior of chlorite in a laboratory-prepared candied butterbur was monitored during the preparation process. It was found that chlorite was either completely removed or decomposed during the bathing and candying processes.

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In 1982, Environment Agency of Japan defined a regulation on total phosphorus and the total nitrogen concentrations in lake water as an index of environmental quality standard to protect from the pollution. At the same time, an official method for the determination of total phosphorus and total nitrogen was published. Therefore, the concentrations of these compounds in lake and river water in the south area of Hyogo prefecture in Japan were determined to be compared with the regulation of the environmental quality standard. Water samples were also taken from the area and Lake Biwa and Yodo River as comparison. The 18 samples among 29 of lake water exceeded the limit (0.1 mg/l) of total phosphorus, while the 19 samples among 29 of lake water exceeded the limit (1.0 mg/l) of total nitrogen.

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