It was made clear that there were many kinds of food containing large amounts of boron, according to the results of our experiments by the previously reported colorimetric (curcumin) method for microdetermination of boron. In this paper, the new simplified methods for detection of boron in foods are reported. The methods are the following: 1) Paraffin-ring filter paper method 2) Sea sand method Furthermore regarding these methods heating temperature, heating time, influence of the added acid on coloration, stability of coloured substance, and effect of NaCl were examined in detail.
It was presumed that nitrofurylacrylic amide (NFA) was adsorbed in eggwhite, albumin and γ-globulin. The adsorption rate of NFA in 10% aqueous solution of eggwhite, albumin and γ-globulin respectively were examined in comparison with each one. Judging from results of the experiments, it was assured that γ-globulin had the greatest adsorption ability and albumin the smallest.
The mixture of nitrofurazone (NFS) and nitrofurylacrylic acid amide (NFA) was able to be analyzed separately, NFS was determined by means of forming nitorofural phenylhydrazone and NFA by the formation of red dye produced by adding the solution of NaClO to NFA dissolved in 75% solution of dimethylformamide. Each of the colorimetric methods was not interfered by other components.
From 17th to 20th in May 1961, 20 persons were poisoned by eating Akasara shellfish (Chlamys nipponensis), one of them died, in Ofunato city facing the Pacific, Iwate prefecture situates in the northern part of Japan. In order to make clear properties of poison which was contained in the shellfish and get methods for determining it chemically and biologically, studies have been carried out in our laboratory on the shellfish. It was demonstrated that paralytic shellfish poison PSP in America and our poison are very similar to each other in their chemical properties; soluble in water, not volatile, stable against heat only in the acidic medium and insoluble in ether, chloroform, ethyl acetate and benzene. The preliminary purification of our poison and the color tests on the attained poison were carried out according to McFarren's procedure for PSP. Then, the careful purification of the poison was tried according to the method for PSP reported by Dr. Schantz et al. The results of our experiments on the purification of the poison are summarized as following; our poison was satisfactorily purified to some extent by the method for PSP, but its behaviours to the purifying agents (ion exchange resin and others) used to our poison seem to be different from PSP in the detailed points and therefore it is doubtful to presume the both poison to be identical. Our purified poison which presumably still includes much impurities, was tested by the papar chromatography. The Rf values obtained, using the three kinds of mixed solvent system, were not identical with those of PSP at all as compared with the reports by Dr. Schantz et al. At last a mixture of our poison and the pure PSP sent by courtesy of Mr. Jensen and Dr. Schantz was examined by means of the same chromatography. It was shown clealy in paper chromatograms that two poisons are chemically quite different from each other. Henceforth our poison is named, we hope, Chlamytoxin after the name of the shellfish, Chlamys nipponensis Kuroda.
Thin layer chromatography was employed for the simplified detection of organophosphorus insecticides and for the separation of insecticides from the substances inhibiting their determination, such as vegetable oil, natural dye and detergent. After development, the insecticide was extracted from adsorbent quantitatively and used for the enzymatic determination.
An incident of paralytic food poisoning was reported to have been caused by shell fish, AKAZARA, (Chlamys Nipponensis Akazara Kuroda) May, 1961, in Ofunato-city, Iwate Prefecture. The noxious shellfish was found mainly in the sea areas of Odachi, the offing of Yamaguchi, and Kawasaki in Ofunato bay, and the toxicity of the shellfish was estimated at 300-8, 000 mouse units per 1g of its mic-gut gland accourding to the method for evaluating the globefish poison. On the contrary, the toxicity was not observed in the shellfish, Akazara, which was caught in Otsuchi bay. The symptoms of this poisoning were quite similar to those of poisoning by Asari broke out 1948 in Toyohashi-city, Aichi prefecture.
A method is described for detecting and determinating low concentration (0.0005 per cent) of nitrofurazone and nitrofurylacrylamide in food. The food containing nitrofurazone and nitrofuryacryllamide is treated with diluted hydrochloric acid, and these substances are extracted with acetone after removal of interfering materials by pre-treatment with n-hexane. Nitrofurazone and nitrofurylacrylamide in the acetone extract are detected by ascending paper chromatography using n-butanol saturated with water. Each substance is well separated and the spots are detected by absorption when the paper is examined in ultraviolet light and with color reagent of a solution of sodium hydroxide. When nitrofurazone or nitrofurylacrylamide is contained alone in food, the substance in the acetone extract is determined by measuring the optical density in each absorption maximum spectrophotometrically.
The methods for determination of nitrofurazone and nitrofurylacrylamide by polarography and column chromatography are described. When nitrofurazone and nitrofurylacrylamide in N, N-dimethylformamide are deter-mined by polarography, ammonium citrate solution (pH 5.0) is an excellent buffer. Relation between their wave heights and the concentrations shows the linearity in a standard graphic paper. However in a case of the mixture of nitrofurazone and nitrofurylacrylamide, each substance is not determined by the polarographic method. In such a case, these substances can be separated by column chromatography. Silica gel in used as an absorbent. Nitrofurylacrylamide is eluted with a mixture of ether and acetone, and nitrofurazone with acetone. These methods have been successfully applied to the analysis of nitrofurazone and nitrofurylacrylamide in preparations and food.