| Summary: | 碩士 === 國立交通大學 === 環境工程系所 === 94 === This paper presents the toxicity data of benzenedicarboxylate(14 phthalate esters、4 terephthalate esters and 2 isophthalate esters) on Psudokirchneriella subcapitata (green algae) assessed by a new algal toxicity testing technique conducted under air-tight environment. Based no DO production, median effect concentration (EC50) varies from 0.037 mg/L (Dihexyl phthalate, DHP) to 344 mg/L(Bis(Methoxyethyl) phthalate, BMOEP). The endpoint of algal DO production reveals more sensitive that from final yield and growth rate. Compared to literature data, Psudokirchneriella subcapitata are apparently more sensitive to the other organisms such as Fathead minnow、Daphnia magan or T. pyroformis besides the low molecular phthalate(Dimethyl phthalate and Diethyl phthalate). Furthermore, good correlations between toxic effects observed from Psudokirchneriella subcapitata and other aquatic organisms were found. Hence, algal toxicity test can be considered as a surrogate test for estimating the toxicity of phthalate esters to Fathead minnow and Daphnia magna.
Quantitative Structure-Activity relationship (QSAR) was established based on chemical hydrophobicity , 1-octanol/water partition coefficient (log P) with R2 equal to 0.88〜0.92. If the parameter of log P* Molecular weight is used, we can get a greater R2 0.95〜0.96. The purpose we used this parameters was not only to get a great R2, but to describe the physiological aspects relative to the mode of action of the chemicals assayed.
Finally, we used the equation of baseline toxicity built by our laboratory, only six compounds had more than 1 residual. According to this result, we determined the mode of action of other 14 compounds were non-polar toxicity.
|
|---|
