食品の保存料, 人工甘味料等の衛生化学的研究 (第4報)

食品中の各種保存料の系統的分析法

抄録

Such food preservatives as salicylic acid (SA), benzoic acid (BA), esters of p-hydroxy benzoica cid (POBA-E), sorbic acid (SOA), dehydroacetic acid (DHA), methylnaphthoquinone (MNQ), nitrofurazone (NFS) and nitrofurylacrylamide (NFA) contained in food are separated with solvents to three groups. When it is difficult to extract the acidic compounds of the food preservatives with solvent, anion exchange resins are used for the uptake of the acidic compounds. The elution of the acidic compounds from the resins is carried out by means of a mixture of glacial acetic acid and acetone.
The food preservatives in fraction I; SA, BA, POBA-E, SOA and DHA are identified by the paper electrophoresis with buffer solution consisted of dimethylformamide-pyridine-acetic acid-water (pH 5.6) or n-butanol-aqueous ammonia-acetic acid-water (pH 5.0) and also by the paper chromatography with cyclohexanol-ammonium carbonate buffer. The spots are detected with ultraviolef light and colorreagents e. g. diazotized sulfanilic acid, diazotized nitroaniline, methyl red or ferric chloride.
The food preservative, MNQ in fraction II is paper-chromatographed with 95% mnethanol by the ascending procedure and detected with ultraviolet light and color reagents e. g. sodium hydroxide, 2, 4-dinitrophenylhydrazine, etc. By the addition of 2, 4-dinitrophenylhydrazine to fraction II, the 2, 4-dinitrophenylhydrazone of MNQ is formed and also paper chromatographed with concentrated aqueous ammonia ascendingly.
The food preservatives, NFS and NFA in fraction III are separated by the ascending paper chromatography with n-butanol saturated with water. The spots are detected with ultraviolet light and colorreagent e. g. sodium hydroxide.
MNc in fraction I and Rf values of the food preservatives in fraction I, II and III are tabulated.