抄録
Simple method for the detection of histamine in fish muscle, based on the extraction of histamine azo-compound with organic solvent, was presented. When p-nitroaniline was used for the preparation of diazo-reagent, using ethyl-acetate as a extracting agent, histamine azocompound was easily transfered into the ester and separated from that of histidine. And furthermore the azo-compound of almost all the diazo-reaction positive substances presumably contained in fish muscle was also kept free from being transfered into the ester. At the high concentratation of histidine, histidine azo-compound slightly passed into the ester, but it was possible to remove this by treating with dilute alkaline solution.
Detection procedure was summarized as follows: Fish muscle extract was obtained by shaking and filtering after being added 20 volumes of water (or succesively 10 volumes of water and of 5% CCl3COOH). To 1.0 cc. of the extract, was added 2.0 cc. of 2.0% Na2CO3. To the above solution, was added 1 cc. of diazo-reagent. After brief standing, 7 cc. of ethylacetate was added to it and its solution was shaken vigorously. Histamine concentration was measured roughly from the intensity of rose color of ester layer. Diazo-reagent was freshly prepared by adding 0.1 cc. of 5% NaNO2 to 5 cc. of 0.1% p-nitroaniline in O.l N HCI solution, and it was used immediately after preparation.
