^(14)C-DDT在罗非鱼体内的积累、分布及降解(英文)

Studies on the Accumulation, Distribution, and Degradation of  14CDDT in Marine Tilapia sp

用示踪法研究海水中１４Ｃ－ＤＤＴ在罗非鱼中的积累分布和降解．结果表明，２４ｈ内鱼体所有器官几乎都达到积累高峰，随后缓慢下降．在第２４ｈ，鱼体各器官对ＤＤＴ的积累能力依次为：肝脏，胆囊，肠，脑，鳃，尾鳍，眼，肌肉和鳞片．肝脏单位重量放射性活度为肌肉的５７倍．对ＤＤＴ降解物的ＴＬＣ分析发现，内脏团中在２ｈ内已经有ＤＤＴ的降解物出现．第６ｈ内脏团中可提取物中ＤＤＴ及其残留物的比例分别为：ＤＤＴ３１．０５％，ＤＤＤ４３．５２％，ＤＤＥ５．６０％，ＤＤＭＵ３．３０％，ＤＤＡ２．３２％，原点未知物１４．２１％．提示ＤＤＴ能在罗非鱼中很快的降解，主要降解产物为ＤＤＤ．这和以往在其它鱼类得出的研究结果不同．水中的放射性活度在４８ｈ内快速减少，此后缓慢上升．对水中标记残留物的ＴＬＣ分析发现，在实验后期水中放射性残留物已基本不是ＤＤＴ．第２６ｄ水样的放射性残留物中，ＤＤＴ只占２．９３％，而原点未知物则占８３．１３％．

Tilapia could rapidly accumulate and degrade 14CDDT. Within 24 hours, the accumulation of DDT in almost all the organs of the fish had reached the peaks and the radioactivity declined from then on. At the 24th hour, the concentration ability of organs to DDT were in the descending sequence as follows: liver, bile, intestine, brain, gill, caudal fin, eye, muscle and scale. The relative radioactivity of liver is more than 57 times of that of muscle. The metabolites could be detected in viscera in the 2nd hour. In the 6th hour, the percentage of extractable residues of viscera were: DDT 3105%, DDD 4352%, DDE 560%, DDMU 330%, DDA 232%, unknown compound at initial point 1421%. Radioactivity in water was declined within 48 hours, and then increased slowly. DDT residues in water were analyzed by TLC and the results showed that in the later period of the experiment, the radioactivity in water was almost not DDT. On the 26th day, the radioactive compounds in water were: DDT 293%, DDD 625%, DDE 195%, DDMU 098%, DDA 176%, unknown compound at initial point 8613%. Concentration factors and their limitations were also discussed.