The qualitative and quantitative analyses by the fluorometric method were studied. Griseofulvin in Miso was extracted with ether and was chromatographed on a thin layer. The measurement of its fluorescence was carried out by use of Auto-fluorodensitometer. The limit of detection per spot was 0.01μg on a thin layer plate, and a straight line relationship was obtained between the amount of griseofulvin and fluorescence intensity within the range of 0.05-0.25μg (per spot). The detection level of griseofulvin in Miso was 0.5ppm.
This method was applied to nine commercial samples of Miso produced in various districts and to three marketted samples of soy produced in Kanto area. From the results, it was affirmed that these products were free from griseofulvin.

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A method for the quantitative analysis of 8 kinds of food colors and 8 kinds of similar dyes, of which 12 dyes were water-soluble and 4 were oil-soluble, was presented. The method consist of paper chromatography and direct densitometry of the resultant spot peak areas on the spots of paper chromatograms transparently scanned through the filter with approximately maximum wave length of each dye in the visible region.
As the result, the integrated readings of peak areas on the spots were approximately proportional to the root square of dye amounts or concentrations. In the total regression equations between peak areas and the root squares of dye amounts, mean value of correlation coefficient was 0.992 with the slit (0.5×5.0mm).

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A method for the quantitative analysis of 4 kinds of monazo-dyes used for food is described. The method consists of paper chromatography and analysis of the resultant spot peak areas by direct densitometry.
The paper-chromatogram-spot volumes of each dye through filters with various wave lengths were approximately proportional to the root square of color concentration as was shown in our previous paper (Shokuhin Eiseigaku Zasshi, 13, 120, 1972.).
The application of direct densitometry to the quantification of the components of monazodyes mixtures was made. For two 2 components mixtures (amaranth and new coccine, tartrazine and sunset yellow FCF), the content of each color was determined densitometrically with reproducibility of 95.7-100.7%. For 4 component mixture of all four dyes above, 84.8-112.1%.

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Previous reports suggest that intestinal bacteria play an important role in the metabolism of sodium cyclamate in animal bodies. Furthermore, the bacteria capable of assimilating sodium cyclamate have been separated from the feces of guinea pigs, and some of their characteristics have been examined, including some enzymatic experiments with cell-free extracts of the bacteria.
In this report, it was elucidated that the bacteria, reported previously, were able to metabolize sodium cyclamate to cyclohexylamine even in the presence of a large amount of other nutrients or cecal contents of guinea pigs.
Additionally, when living cells of the bacteria were orally administered to guinea pigs, together with 1% sodium cyclamate solution as drinking water, cyclohexylamine was excreted in the urine earlier than in the control.
Absorption of cyclohexylamine through the membrane of the intestine and excretion in the urine were demonstrated in another experiment by direct injection of cyclohexylamine into the cecum of guinea pigs.
These observations are further evidences to support the actual participation of intestinal bacteria in the metabolism of sodium cyclamate.

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It has been considered that the colorimetric method with methylene blue is one of the best methods for determining very small amounts of anionic surfactants. However, in the case of vegetables and fruits, this method is not necessarily satisfactory owing to interference by methylene blue active substances (MBAS) other than anionic surfactants, contained in vegetables and fruits. Because of the above reason, small amount of a residual surfactant remaining in them cannot be detected precisely, especially when the blank value is high, to give a higher value of the surfactant than an expected value.
This paper describes a way of determination of residual alkylbenzene sulfonate in tomato juice by removing MBAS. The procedure is as follows. After evaporating alcohol from the alcohol extract of a sample, the residue is treated with petroleum ether and washed with chloroform. The amount of the surfactant in the aqueous layer is then determined according to the Abbott's method with methylene blue.

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