Hygienic safety of rubbor articles was reviewed, concentrating on raw rubber, cross-linking agent, vulcanizing agent, vulcanization accelerator, antioxidant, reinforcing agent, and filler. Since the hygiene problems related to rubber have been investigated for only 10 years, many aspects are judged from experience, and very few data are available on chronic and carcinogenic test. It is necessary for the discussion on the hygienic safety of rubber articles to have the data not only on acute toxicity but also on sub-acute and chronic toxicity, carcinogenicity, teratogenicity and mutagenicity.

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A simple method for the determination of sucrose monopalmitate (SMP) by the use of gas chromatography is described. SMP was trimethylsilylated with a mixture of hexamethyldisilazane and trimethylchlorosilane or of N, O-bis (trimethylsilyl)-acetamide and trimethylchlorosilane in anhydrous pyridine. Trimethylsilylated SMP was introduced into a gas chromatograph equipped with a hydrogen flame ionization detector and a glass column (0.5 m×3 mm) packed with 3% OV-17 on Gaschrome Q at 260°in N₂ with a flow rate of 55 ml/min. SMP was resolved from sucrose monostearate (SMS) and was determined by the use of SMS or trilaurin as an internal standard. A linear relationship between the peak height ratio of trimethylsilylated SMP to internal standard and the amount of trimethylsilylated SMP injected was obtained up to at least the amount equivalent to 25 μg of SMP. Coexistent palmitate in the sample was also determined, after treatment of the sample with the trimethylsilylating reagents mentioned above, by employing the same gas chromatograph equipped with another glass column (1.0 m×3 mm) packed with 3% OV-17 on Gaschrome Q. The recoveries of SMP and palmitate from rat plasma or lymph were satisfactory.

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Since metallothionein binds strongly with cadmium at a definite molar ratio, an examination was made on the method for quantitative determination of metallothionein using this characteristic. 1) Free cadmium was removed by heating with a guinea pig hemolysate and subsequent separation by centrifugation. 2) Zinc in the metallothionein fraction was completely substituted with cadmium by its addition and treatment of this fraction with the guinea pig hemolysate resulted in approximately complete removal of cadmium other than that in the metallothionein fraction. 3) This method showed a good linearity in the wide range of cadmium content of 0.2 to 4.0 μg/ml. 4) Result obtained from this method was compared with the existing method of measuring the amount of metal (s) bound to the metallothionein fraction after gel filtration in the liver and kidneys of rats given cadmium, and the values were in approximate agreement. Correlation coefficient was 0.98 for the liver and 0.95 for the kidneys.

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Lyophilized and powdered oyster meat was extracted with acetone, and the residue was extracted further with 0.5 M NaCl. The NaCl-soluble fraction was dialyzed against the same NaCl solution. The heavy metal content in each sample (samples A-G) was determined by atomic absorption spectroscopy, and an aliquot of the NaCl-soluble fraction was chromatographed over Sephadex G-50. 1) Acetone failed to extract 99% of Zn, Cd, and Cu in the freeze-dried oyster meat while 35% of Zn, 16% of Cd, and 41% of Cu in the acetone-insoluble fraction (fraction C) were extracted with 0.5 M NaCl solution, and 91% of Zn, 82% of Cd, and 78% of Cu in the NaCl-soluble fraction (fraction D) were dialyzed. 2) Heavy metals in fraction D appeared in two peaks of high and low molecular fractions in Sephadex gel filtration chromatography. Heavy metals in the high molecular fraction were not dissociated and were not dialyzed in 0.5 M NaCl solution. 3) When the oyster was bred in an artificial sea water containing various concentrations of Cd, the content of Cd in oyster meat increased in proportion to the concentration of Cd in artificial sea water. On the other hand, the content of Zn in oyster meat decreased with the increase of Cd in artificial sea water. 4) Accumulation of Cd in oyster meat did not decrease for 1 week after immersion of oyster in natural sea water.

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For the purpose of detecting micro-quantity components in odorous fish meat, high-resolution gas chromatography-mass measurement was made, and tetralin was determined in fish meat, other than the components that had been recognized as the substances responsible for offensive odor in odorous fish. It is considered that tetralin does not act the main role as an offensive odor substance in the fish, because it is seldom detected but it is one of the notable components as new environmental pollutants.

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Electron capture detector-gas chromatography was investigated for determination of ultra-micro amount of chromium which was converted to a chromium chelate [tris-(1, 1, 1-trifluoro-2, 4-pentanedionato) chromium (III), Cr (TFA)₃] by reacting with 1, 1, 1-trifluoro-2, 4-pentanedione (TFA). A mixture of 10 ml of a sample solution containing less 100 ppb of Cr (III), 5 ml of TFA-benzene solution, and 2 ml of acetate buffer of pH 4.6 was sealed in a glass ampule, and submitted to two times of heating-mixing operation (heating at 100°for 3 min and mixing vigorously for 1 min), and cooled to room temperature. Then the ampule was broken to separate the benzene fraction from the aqueous layer, and the benzene fraction was washed with 5 ml of 0.5 N NaOH and twice with 5 ml each of water. The benzene fraction was submitted to gas chromatography. In the gas chromatography, a calibration curve showed a linear relationship between the weight of Cr (TFA)₃ peak in the gas chromatogram and amount of Cr up to 80 ng/10 ml. The proposed method was found to be effective for determination of Cr (III), but it needed reduction with hydroquinone in order to measure Cr (VI). To determine Cr content in a deposit sample, the sample was divided into two fractions, soluble and insoluble fractions. From the results obtained by this method, Cr (VI) was found scarce in both fractions. Therefore, Cr in the deposit sample might be mainly present in the state of Cr (III).

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A simple and rapid determination of linear dodecylbenzenesulfonate (LAS) in natural and waste water was investigated. A water sample containing 3-30 μg of LAS was adjusted to the concentration of 2.7-3.2% sodium chloride, and shaken with methyl isobutyl ketone (MIBK). LAS and alcoholic anionic surfactants were extracted with MIBK, while many kinds of substances interfering the measurment of LAS were not extracted. Alcoholic anionic surfactants in MIBK were decomposed easily by heating at 80-85°for 5 min with conc. hydrochloric acid but LAS was stable. When the resulting mixture was diluted with 1.2% sodium chloride, the MIBK layer separated. After the separated MIBK layer was washed with 0.1 M sodium borate solution and then with 0.1 M phosphate-hydrochloric acid buffer of pH 2.5-3, it was shaken with 0.0025% Methylene Blue solution. The absorbance of LAS-Methylene Blue complex in MIBK layer was measured at 658 nm. The average recovery of LAS added to water sample was higher than 95%, except in highly polluted water.

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In order confirm the role of volatile fatty acids, aromatic hydrocarbons, and phenol found as the main substances responsible for offensive odor of fish meat, odor-imparting experiments were carried out on these three components, their concentrations being based on their analytical values obtained from river water in which the fish with unpleasant odor lived. The odor of fish bred in such a solution was close to that of the fish in natural waters but there was still a very fine difference, and the odor of the odorous fish itself was not the same, indicating that it is difficult to reproduce the original odor due to a slight difference in the componental principles. It was found that there was a limit to the transfer of odor to fish from the water area, which is of importance in the counter-measure for odorous fish, and the limit exist between the concentration of 1st and 2 nd experiments in Table I. Tetra methyl pyrazine and tetralin were found by GC-MS analysis in the offensive odor fish meat, but fish was not scented with tetra methyl pyrazine. Taste of fish scented with tetralin was different from that of the offensive odor fish. Therefore, the compounds did not responsible for offensive odor substances.

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