It has been known that tin is formed an insoluble colloidal complex with phenylfluorone (PF). The formation of the complex was modified by the adjustment of pH value and the addition of ammoninm sulfate. When the solution containing tin-PF complex was shaken with water-inmiscible organic solvent, the complex was collected on the surface of the organic solvent. The collected complex was dissolved in hydrochloric acid and was decomporsed into tin and PF. The concentration of tin was determined spectrophoto-metrically. The procedure was as follows. After 25-30ml of the solution containing 1-10μg of tin was adjusted to pH 2.0 with 10% ammonia water, 1-3g of ammonium sulfate and 10ml of 0.0015% PF ethaonl solution were added to 40ml of the solution. After standing for 20-25 minutes, the solution was adjusted to about pH 1 with 2N hydrochloric acid, and was shaken with 15ml of n-hexane. The collected complex was dissolved in 10ml of 6N hydrochloric acid after washing with 15ml of 0.1N hydrochloric acid in 20% ethanol, and then the absorbance of the colored solution was measured at 455mμ of wave length by a spectrophotometer.
In order to carry out simultaneous determination of six kinds of synthetic antioxidant in edible oils, the oil was dissolved in pentane and extracted with acetonitrile saturated with pentane. A definite quantity of benzophenone was added to the extract as internal standard, and the solution was concentrated by Kuderna-Danish concentrator. A small amount of the oil that separated from antioxidants on thin-layer chromatogram was removed, and extracted antioxydants and benzophenone were submitted to gas-liquid chromatography as a trimethylsilane derivatives. Recovery rates of n-propyl gallate and iso-amyl gallate were slightly lower and precisions of determination were also lower than others, however, the determimatien of butyl hydroxy anisol, dibutyl hydroxy toluene, ethyl protocatecuate and nordihydroguaiaretic acid were fully satisfactory.
Mycological examination was carried out on a total of 105 samples of buckwheat and its products including 16 batches of grains, 57 of flours and 32 of dried noodles. All samples were collected from marketing channeles in Tokyo. Representative strains of the isolates from these samples were examined chemically for their producing ability of carcinogenic mycotoxins such as aflatoxins and sterigmatocystin. To isolate fungi was applied the modified Inagaki and Kurata's method, which used two kinds of Potato Dextrose Agar medium containing either 20% glucose or 100μg chloramphenicol per ml. Filamentous fungal counts of the grains, flours and noodles were estimated as 3-88/50 grains (average 51), 100-46, 250/gram (average 6, 055) and 50-7, 025/gram (average 1, 178) respectively. Predominant genera of fungi among the total fungal isolates (383, 708) from all the samples examined were the genera of Aspergillus, Penicillium and Cladosporium. Of the total isolates, 3, 389 isolates (0.9%) were found to be the Aspergillus flavus group, and 48, 428 (12.6%) and 1, 357 (0.4%) isolates were identified as Aspergillus versicolor and Fusarium spp. respectively. Results of the bioproduction test with chloroform extracts of culture filtrates of the isolates indicated that one each strain of A. flavus and Rhizopus sp. from the grains samples were found to be producing aflatoxin B1 and B2 simultaneously. Of the aflatoxins-producing strains belonging to the A. flavus, three strains from the flours showed to have the aflatoxin producing ability (aflatoxin B 15.2-29.2ppm) as high as that of A. flavus NRRL 3000 used as the references strain. One strain of A. versicolor from the flour was recognized as sterigmatocystin-producing strain.
Saccharin sodium was administered to pregnant rats and mice through a stomach tube during the critical period of the organogenesis in the fetuses and the teratogenic effects of the sweetener were examined. In rats, the sweetener was given once daily at doses of 0.48, 0.95, 1.9 and 3.8g/kg for 7 days from day 7 to 13 of gestation, and in mice only once on day 6 of gestation at dose levels of 62.3, 125, 250, 500 and 1, 000mg/kg. In the 3.8g/kg group of pregnant rats, temporary suppression of body weight gain and reduction of food consumption were observed following the administration of the sweetener, but pregnancy, delivery and weaning were maintained well without any disorders. In lower dose groups, also no deleterious effects on lactation and postnatal development of new borns were observed. No abnormalities of the fetuses such as resorption, malformation and retarded development have been observed in rats and mice and also of the weanlings in rats.
Identification of azo-, and disazo-dyes by gas chromatography was studied using their reduction products, aniline, toluidine, xylidine, and phenylenediamine. Aniline. three near boiling point isomers of toluidine, and three isomers of xylidine deriyed from azo-dyes were sufficiently detected each other on 5% PEG 20M+1.2% KOH/Chromosorb W column at 130°, and three isomers of phenylenediamine and p-toluylenediamine deriyed from disazo-dyes were given good results using same column at 180°C.
Detection of residual antibiotics, such as penicillin (PC), streptomycin (SM), and oxytetracyclin (OTC) in slaughtered swine carcases was made by the standard bioassay technique, using Sarcina lutea ATCC 9341, Bacillus subtilis ATCC 6633, and Bacillus cereus var. mycoides ATCC 11778, respectively. Specimens obtained for the examination were neck muscle, liver and kidney of 29 pigs which had been treated with the above mentioned antibiotics. In addition to this field survey, an experimental study on the reliability of disk method, for the detection of penicillin incorporated in pork extract, was also carried out comparing with the standard cup method. As the results it was found that 1 (3.7%) out of 27 muscles, 6 (29.0%) of 21 livers, and 4 (20.0%) kidney contained 0.16-1.1IU/g of PC, while 3 of 21 (14.2%) liver and 2 of 21 (9.5%) kidney contained 0.15-0.75μg/g of SM. However, none of the specimen tested contained any detectable amount of OTC. As for the reliability of the disk method, it was found that almost the same sensitivity with that of the cup method could be achieved, especially at a lower concentration of the antibiotics. Therefore, it is recommeded to use disk method as a routine screenig procedure for the detection of residual penicillin in animal tissues.