Motohiko Iwaida

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The 2,4-xylenol method was modified and a gas-liquid chromatographic (GLC) method was developed for nitrate and nitrite determinations in several foods. Either a flame ionization (FID) or an electron capture detector (ECD) can be used. Proteins and fats are removed from warm alkaline water with zinc sulfate and filtered. The filtrate is evaporated to(More)
Improved 4-aminoantipyrine (4-AA) colorimetry was developed for the detection of minute quantities of residual hydrogen peroxide in several kinds of food. Hydrogen peroxide in the sample was stabilized with potassium bromate and extracted with cold methanol. The methanol extract was diluted with phosphate buffer, protein was eliminated with zinc sulfate,(More)
Forty-four kinds of organic nitrogen compounds as well as 37 kinds of dyes which contained nitrogen were subjected to TLm test by use of Himedaka (Oryzias latipes) and the results were compared with their partition coefficients between n-octanol and water. Concerning organic nitrogen compounds, such good correlation was observed among them that the larger(More)
The toxicity of xanthene dyes were studied by various interaction between the dyes and the components in vital body. (1) An increase in the amount of Rose Bengale adsorbed on the gill of fish was followed by the increase in red corpuscle number, and it was assumed that the death of fish in xanthene dye solution was due to anoxemia. (2) Binding capacity of(More)
In order to have an effective utilization of the radio wave resources, it is important to estimate propagation path in the urban area. In our previous works, we have shown that the shape and material of wedges do not affect the diffracted fields. In this paper, we analyze the reflected and diffracted fields by one or two wedges and compare the effects that(More)
Estimation of the scattering of electromagnetic waves by buildings and other obstacles is very important for wireless communications in urban area. In our previous work, we have examined the diffracted fields by two horizontal edges with an arbitrary angle. In this paper, we consider the diffracted fields by two edges with an arbitrary angle which change in(More)
Reason of acute toxicity to fish caused by coal-tar dyes and their industrial effluents were studied from the three points of view. 1) Partition coefficient (n-octanol/water) was determined on several coal-tar dyes, and it was found that the larger the ratio was, the stronger was toxicity to fish. 2) As a result of determination about existent form of(More)