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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.

A Colorimetric method, using p-nitrobenzaldehyde and o-dinitrobenzene, combined with the diffusion analysis was established for the determination of cyanide in food.After the addition of 0.4ml of the absorbing reagent (0.15N KOH) into the inner chamber and then 1-2ml of sample solution (distillate containing 0-150ng CN) and 2ml of 10% H2SO4 solution into the outer, the standard unit was allowed to stand for 3 hours at 30-35°C. The content of the inner chamber was treated with chromogenic reagent (0.25ml of 0.1M p-nitrobenzaldehyde methylcellosolve solution and 0.25ml of 0.1M o-dinitrobenzene methylcellosolve solution) and allowed to stand for 30 minutes at room temperature.After diluting the colored solution with 5ml of methylcellosolve, the absorbance at 560mμ of the solution was measured.The content of cyanide (CN):0-464ppm (42 samples) for Beans.0.014-129ppm (14 samples) for Apricot kernel.0.008-0.018ppm (3 samples) for Corn.0-0.013ppm (5 samples) for Tapioca.38.2-44.5ppm (4 samples) for Chips of Cassava root.0-3.4ppm (15 samples) for Fruit wine.0 (10 samples) for “Sake”, Whisky and Brandy.

We carried out the determination of residual ABS remained in vegetable and fruits treated with the chemical detergent.1) Chemical methodThere are few reports on the determination of ABS contained in vegetables and fruits, but in this case we adopted the following method; a sample sliced and miced as finely as possible is extracted with alcohol containing hydrochloric acid. After evaporating alcohol from the alcoholic extract, the residual fluid is adjusted to pH 10 and filtered. The filterate is washed with petroether. The petroether-washed liquid is treated according to Longwell and Maniece method.As a result of our experiments we could find the following.Vegetables: The residual detergent was 20-70ppm after soaking a sample in 0.05 per cent ABS solution (usual concentration for use) for 1-5 minutes, but when once washed with water after soaking, the residuals were decreased to 4-13ppm, when 3 times to 2-7ppm.Hurt vegetables showed a larger amount of the residues as compared with normal ones.Fruits: 0.5-2ppm of the residues were found to remain in a sample after washing with water.In the case of strawberry as a sample, it was found the longer time of soaking the more residues of the detergent.On the contrary apples showed no more than 0.5ppm of the residual detergent after soaking in the solution within 1-5 minutes.2) Radiochemical methodAs a result of our radiochemical experiments, when 10g of spinach was soaked in 150ml of 0.05 per cent ABS solution containing labeled sodium alkylbenzenesulfonate for 10 seconds, and washed again with 300ml of water, we found 2ppm of ABS remained in the sample. And when soaked for 30 minutes under the same conditions, 12ppm of ABS in the sample.

Dibutyl tin compounds are widely used as the stabilizer of polyvinyl chloride. The determination of such dibutyl tin compounds used can be successfully carried out by square wave polarography using mercuric pool as the electrode. Various kinds of polyvinyl chloride films were manufactured by use of dibutyl tin compounds (chloride, maleate and laurate) as the stabilizer, then the amount of stabilizer eluted by 0.01N hydrochloric acid, 4v/v% acetic acid or 20v/v% ethanol was measured by polarography. From the results it became clear that the organic tin in the stabilizer is more apt to be eluted by ethanol than that in dibutyl tin maleate. The stabilizer was scarcely eluted from rigid polyvinyl chloride in the experimental conditions.

1. Through our research into the metabolism in rabbit of Naphthol Yellow S (NYS), it was clarified that NYS was excreted as the unchanged one without forming glucuronide or sulfate.2. About 10% and 50-70% of the amount of NYS administered to the test animals per os and through the subcutaneous injection respectively were excreted as unchanged NYS. In both cases most of them were found in the test animal's urine obtained within the first 24hrs. After the administration and scanty in the one within the second 24hrs. The concentration in the test animal's blood of NYS amounted to its highest level in 2hrs. after the administration per os and in 30min. after the subcutaneous method, then it decreased to the normal level of its concentration showed before the administrations. In the liver, kidney and other internal organs of the test animals which had completely discharged NYS no residue of deposited or remained NYS was discovered.3. We could measure the changes of the NYS concentration in the test animal's blood by means of the photoelectric colorimetry. Protein-excluding agents, measurable range, accuracy, etc. necessary for carrying out the colorimetrical procedure were investigated and thereby, basic important conditions for the measurement were established.4. In the sample urine obtained from the administered animals we could detect a red substance, presumably one of the metabolites, by the partition paper chromatography and isolate it by the column chromatography. But its properties are remained to be studied.

For the purpose to elucidate the type of mercury compounds present in agricultural products treated with organomercuric fungicides, behavior of phenylmercuric acetate and methylmercuric chloride within several kinds of young plants was studied.Both compounds were found to be decomposed, to some extent, to inorganic mercuric compound. It was shown by thin-layer chromatography in cooperation with X-ray fluorecence analysis that phenylmercuric compound was present in rice bran.

The color reactions of 75 samples of of phenols with p-nitrobenzenediazonium fluoroborate in alkaline methanolic solution were studied spectrophotometrically (see Table 1, 2, 3 and 4). The wavelengths at maximum absorption were ranged from 445 to 616mμ.The coloring matters formed by the color reactions between 8 samples of phenols and p-nitrobenzenediazonium fluoroborate were separated on Silica gel plate. The Rf values of the coloring matters were shown in Table 5.

はち蜜中のジアスターゼ (α-アミラーゼ) 活性をよう素でんぷん反応による比色法によって測定し, 結果をジアスターゼ数によって表示した。本法を市販はち蜜30種類および採取はち蜜3種類に応用した結果, 後者はいずれもジアスターゼ数8以上であったが市販はち蜜は27種類が8未満であって, 明らかに加熱の影響が認められた。

BHT is a very effective antioxidant for fats and oils. Its combination with other antioxidants is often used. That has indicated the need for a specific and simple method for its quantitative determination.The method presented in this paper is based on separation of BHT from fat or oil by steam distillation, extraction with carbone tetrachloride, application of thin layer chromatography, color reaction of spots with phosphomolybdic acid and measurement of the spot areas.There was a linear relationship between the square root of the spot area and the logarithm of the concentration of BHT (0.25 to 5.0mg/ml). The per cent recovery of BHT from edible oils (100 to 300ppm) was 98±10per cent.

The coloring matters formed by the color reaction between chlorophenols and 4-aminoantipyrine were separated on silica gel.Glass plates coated with “Silica gel G” to a thickness of 250μ were dried in an oven at 110° for 1 hour.The mixture of the coloring matters (CHCl3 extracts, 0.01-0.03μg as each chlorophenol) was introduced by means of a micropipette at a corner 1.5cm from the lower edge of the plate and developed with the solvent mixtures (see Table 1, 2) until the solvent front reached a distance of 10cm from the starting point on the plate.As each spot gives a red color or orange color, this method has no need of detection reagent.The coloring matters were isolated and it was confirmed that the couplings of 4-aminoantipyrine with the chlorophenols take place in the position para to phenolic OH group by Ultraviolet absorption spectra, Visible absorption spectra, Infrared absorption spectra and thin-layer chromatography of the coloring matters.

In view of the unique position of milk and milk products in human nutrition, FAO prepared in 1957 "Code of Principles concerning Milk and Milk Products" with the entire assistance of the International Dairy Federation. It contains the designations, definitions and standards for milk and milk products. Here, an explanatory note on the Code of Principles was given, comparing each article of the code with the domestic laws and orders.

The wave length of maximum absorption (λmax.) of sorbic acid and its molar absorbancy index (∈) change depending upon pH of solutions. However, they were fixed and constant below pH 2.5 and since it was easy to keep pH below 2, absorbancy was read at a pH range of 0.5 to 2.According to this method, the two calibration curves formed straight lines between 0.5μg/ml and 3.0μg/ml. E264-E275 seemed, however, to provide better accuracy and precision for calibration and determination than the other because while the backgrounds at 264mμ and 275mμ, due to impurities from prunes, were too large to be neglected, there was little difference between them.

The authors examined trichloracetic acid extract of cod and Alaska pollack meat as to the substances which might interfere the color reaction of formaldehyde with acetylacetone and found no appreciable disturbance during the course of the determination.This method, originally proposed by Nash in 1953, was then applied to the examination of formaldehyde content of the frozen meat of cod and Alaska pollack. The amount of formaldehyde in back muscle of cod was in a range between 2 and 5mg% and in Alaska pollack, 3.7 to 5.7mg%, respectively. However, the formaldehyde content in the back muscle of these fishes was observed lower than that of skin or dark muscle portion.No remarkable change was noticed in the amount of formaldehyde in these fishes during cold storage at -20°C for six months. But, a slight increase in the formaldehyde content was shown in the sample of cod muscle after four weeks' storage at -5°C, which had been kept at -20°C for five months prior to store at -5°C.A decrease in the amount of formaldehyde was indicated in cod meat when the samples reached a stage of incipient spoilage under a temperature of 16°C and 3°C.The authors conclude that formaldehyde occurs spontaneously in the tissues of cod and Alaska pollack.

About 10-100μg of copper (II) in 40ml of solution of a pH 4-7 have been determined by spectrophotometric titration at 26mμ, with 0.001M or 0.01M NN′-ethylenediaminedipropionic acid (EDDP) solution, and the error was 1-2%. Ca(II), Mg(II), Ni(II), Pb(II), Zn(II), and Hg(II) did not interfere with the determination of copper, but Fe(III) interfered slightly.Copper in foods was also determined by this method, after the foods were ashed in a electric furnace at 400-500°C and dissolved in 0.1M hydrochloric acid.