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Biomedical subjects

M Iwaida

Publications and source records attributed to M Iwaida.

At least 37 records · Page 2Linked to original sources
PubMed1978

Biochemical decomposition of coal-tar dyes. I. Biochemical decomposition and identification of decomposed products.

Biochemical degradation test of food coal-tar dyes using sludge was studied in order to evaluate their safety. It was found that some dyes were little decomposed under aerobic condition but four azo dyes were readily decomposed under anaerobic condition. These were Food Yellow No. 4, No. 5, and Food Red No. 2, No. 102. Decomposed products of these four azo dyes by sludge under anaerobic condition were identified as sulfonilic, naphthionic acids and so on.

Aerobiosis↗
PubMed1978

Biochemical decomposition of coal-tar dyes. II. Acute toxicity of coal-tar dyes and their decomposed products.

Twenty kinds of coal-tar dyes were subjected to median tolerance limit (TLm) test by use of Himedaka (Oryzias latipes) for the comparision of their acute toxicities. It became clear that 4 kinds of halogens substituted xanthene compounds dyes showed strong acute toxicities. From the fact that uranine had the lower acute toxicity than halogens substituted compounds and the toxicities of these 4 dyes increased through irradiation, it was assumed that halogen atoms in dyes might be responsible for these strong acute toxicities to fish.

Anaerobiosis↗
PubMed1978

Gas-liquid chromatographic determination of nitrate and nitrite in cheese, ham, fish sausage, cod roes, and salmon roes.

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 dryness, redissolved in water, and reacted with 2,4-xylenol in the presence of sulfuric acid to form 6-nitro-2,4-xylenol. Interfering chlorides are precipitated with silver sulfate and the nitrosylenol is extracted with hexane, concentrated, and injected. Nitrite in the filtrate is distilled at pH 5, collected in alkaline solution, and dried. The residue is oxidized to nitrate with permanganate in the presence of sulfuric acid, and then chromatographed in the same manner as nitrate. Recoveries from several foods were 83--100% for nitrate and 80--100% for nitrite. The limit of sensitivity was 0.1 ppm for both residues.

Cheese↗