水質汚濁斃死魚の死因判定法について-XI

Abstract

In this paper, an attempt was made to detect Sn in the body of fish (Carassius auratus) killed by tin plating solutions. Sn content of tissues was determined by the phenylfluorone method. In tin plating, two kinds of plating solutions are commonly used, viz, alkaline and acid (Table 2). Experiments showed that the 48 hour median tolerance limits of these 2 kinds of tin plating solutions to goldfish were approximately 100 ppm Sn (Table 3 and 4). Sn wan not detected in control fish bodies, but was clearly detected in the bodies of fish killed by either of the two kinds of solutions. The bodies of fishkilled by tin plating solutions showed values higher than 13.0γ/g Sn, while the bodies of fish still living in tin plating solutions showed values lower than that. It was also possible to detect Sn even in fish washed by running tap water for 24 hours after death. The distribution of tin in seven parts of the fish body was examined under two conditions. Sn was detected in all the parts examined under the condition that fish were killed by tin plating solutions. Under another condition where the fish were soaked in tin plating solutions for 15-24 hours after being killed by suffocation. Sn was detected in skin, gill and muscle, but not in the spleen, hepatopancreas and kidney (Table 5, 6, 7 and 8). The bodies of fish killed by solutions containing organic tin compounds showed very low values of tin content as compared with fish killed by tin plating solutions (Table 9).