Irritation and allergy induced by an enzyme used for detergents (alkali protease) and an enzyme detergent were examined on the skin of guinea pigs, rabbits, and humans. When the concentrated enzyme is adhered and left on the skin and the mucous membrane of an eye, these tissues are considerably irritated. However, these irritations are avoided by washing immediately. Statistically significant difference was not found in the degree of skin roughness between detergents containing an enzyme and conventional detergents.

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Formation of alkylmercury compounds by ultraviolet irradiation of inorganic mercurial together with organic compounds in water was examined. The aqueous solution (100ml) of mercuric chloride (2 mmoles) was irradiated in the presence of acetic acid, propionic acid, methanol, or ethanol (10 mmoles) for 20 hr with ultraviolet ray (2537 Å) at 20°, and the reaction products isolated by the extraction method for alkylmercury compounds were subjected to qualitative and quanti tative analyses using thinlayer chromatography, mercury analyser, and gas chromatography. It was found that irradiation of mercuric chloride in the presence of acetic acid, methanol, or ethanol in water gave methylmercury compound in 0.12, 0.00006, and 0.02% yield of respectively. Irradiation of mercuric chloride in the presence of propionic acid gave methylmercury and ethylmercury compounds at the proportion of 0.00046 and 0.00004%, respectively.

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Growth inhibitory action of some quaternary ammonium-type detergents against baker's yeast was examined. Both lauryldimethylbenzyl ammonium chloride (L-Bz) and laurydimethyl-(3-chloro-2-hydroxypropyl) ammonium chloride (L-Ep) inhibited growth of the cells in the logarithmic phase of multiplication, and pH-growth inhibition curve similar to those well established in other cationic detergents was obtained. Supplementation of nitrogenous compounds, such as urea, L-aspartic acid, L-glutamic acid, casamino acid, pyrimidines, and purines, showed no significant effect on the inhibitory activity of the detergents. Exposure of the resting cells to the detergents at concentrations of 10^-5M to 10^-4M for 3 hr resulted in a progressive increase in the elution of 260 mμ-absorbing materials from the cells, as the detergent concentration increased, but its extent was reduced at a concentration of 10^-3M of the detergents. The yeast grown in the medium containing Bz-type detergents (L-Bz and cetyldimethylbenzylammonium chloride) at a concentration sufficient to inhibit the growth was found to contain more acid-soluble 260mμ-absorbing materials (per protein) as compared with the control cells, whereas in the case of Ep-type detergents (L-Ep and cetyldimethyl-3-chloro-2-hydroxypropyl ammonium chloride) little effect was observed. The syntheses of nucleic acids and protein in the growing cells were inhibited to approximately the same extent by the detergents tested.

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Sulfonated sites in quinoline Yellow WS, which is distributed under the name of "D & C Yellow No.203"have not been clarified as yet. Treatment of 2-(2'-quinolyl)-1, 3-indandione with fuming sulfuric acid, gave several sulfonated products and two of product dye were identified as 2-(2'-quinolyl)-1, 3-indandione-6'-sulfonic acid and 2-(2'-quinoly)-1, 3-indandione-5, 6'-disulfonic acid by nuclear magnetic resonance, infrared and mass spectra. Commercial samples of quinoline Yellow WS consist of the disodium 2-(2'-quinolyl)-1, 3-indandione-5, 6'-disulfonate and contain other sulfonated derivatives.

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A colorimetric method for the determination of cyclamate in foods, based on the reaction of cyclohexanol with vanillin-sulfuric acid reagent, was established. After separation of cyclamate from other components by dialysis pretreatment, cyclamate was converted to cyclohexyl nitrite with nitrous acid under cooling in an ice bath and then to cyclohexanol with sulfamic acid. Cyclohexanol was extracted with ether. After the addition of water to the extract, the ether was evaporated by vigorous stirring using a mixer at room temperature. Vanillin-sulfuric acid reagent was added little by little to the remaining water layer containing cyclohexanol under cooling in an ice bath and warmed for 20 minutes at 70°to form a greenish product. The colored solution was measured spectrophotometrically at 655 mμ. The recovery of sodium cyclamate added to some foods was 93.2-98.8%.

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A method was developed for the separation of nitrite from food products by ion-exchange column chromatography. The sample was extracted with water at pH 9.0, and the filtrate was transfered to a column of Amberlite IRA-410 (Cl form). Nitrite was eluted with solvent system consisting of methanol and 2% sodium chloride solution. Nitrite in the effluent was determined by colorimetry using sulfanilamide and N-naphthylethylenediamine. Recovery of added nitrite from various food products was 87-98%. Ion-exchange chromatography was found to be an efficient and reproducible technique for removing extraneous materials from extracts.

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In order to study the effect of free chlorine in city water on digestive enzymes, inhibition of the activities of crystalline enzyme preparations was measured at various concentrations of hypochlorite. Most of the enzymic activities were found to be somewhat affected at the concentration as small as 0.2 ppm of free chlorine, while swine pancreatic amylase exhibited a slight insensitivity. More than 40% of the activities of all enzymes tested were inhibited by the concentration of 1.0 ppm of chlorine under the experimental conditions used in this study.

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Aqueous solution of sorbic acid (0.32 mg %) was irradiated with ⁶⁰Co γ-ray (dose rate 2.48×10⁴ rad/hr) in doses ranging from 0 to to 2.175×10⁴ rad, and decomposition of the acid was examined by spectrophotometry. Absorbance at λ max 255 nm due to sorbic acid decreased with increasing radiation dose and the G (-sorbic acid) value was calculated from the decreasing rate of the absorbance to give 1.85. An aqueous solution of sorbic acid irradiated at the dose 7×10⁵-13×10⁵ rad showed a stronger antibacterial activity than non-irradiated solution against E. coli, in spite of the decrease of sorbic acid in the solution. Therefore, new antibacterial substance was assumed to have been produced in the solution by γ-ray irradiation. This irradiated solution also showed antibacterial activity against 5 other kinds of bacteria. It was also proved that the presence of O₂ gas might be essential for the production of the new antibacterial substnce by experiments on antibacterial activity of irradiated solutions sealed with or without O₂ gas.

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An examination was made on the sensitive spectrophotometric determination of ammonia-nitrogen in water. Ammonia was determined indirectly by measuring the blue complex produced by reaction with potassium iodide-starch reagent and chloramine compound, which was formed by the reaction of ammonia and hypochlorite at pH 5.4. Unreacted hypochlorite was destroyed with ferrous sulfate before addition of potassium iodide-starch reagent. The absorbance of developed color of the blue complex was measured at 570 mμ. The method was applicable for the determination of ammonia-nitrogen in the range of 0.01 to 0.4 ppm, at between 21 and 26°. The standard deviation was 2.2% on an average absorbance 0.496 of a sample containing 0.2 ppm of ammonia-nitrogen.

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