| Summary: | 博士 === 國立中興大學 === 獸醫學系暨研究所 === 102 === This study is to research the toxicity and anesthetic effectiveness of TMS (tricaine methanesulfonate, TMS) on tilapia (Oreochromis hybrids). The method applied was high- performance liquid chromatography (HPLC) plus ultraviolet detector to examine and the residues of TMS in the tissue and serum of tilapia after eight hours of immersion in TMS. Then after, by analyzing the behavior of tilapia during the final anesthesia and resuscitation, we can divide it in to 6 and 4 stages respectively. The results show that under different temperatures and concentrations of TMS, the effectiveness of anesthesia and time of resuscitation varies. The result reveals that the time needed to reach stage A4 of anesthesia shortens as concentration of TMS and temperature rise. Also, the time needed for resuscitation is fixated around five minutes at a concentration of 340 ppm. Furthermore, when the concentration of TMS is controlled around 260~300 ppm, the time needed for tilapia to reach A4 stage and R3 stage is 3 minutes and 5 minutes respectively. These results consistent under different temperatures, thus, under proper maintenance of anesthesia, we may be able to apply it to surgery for tilapia. After observing the effectiveness of anesthesia, we performed tests based on 5 log concentration between maximum safety dose and minimum lethal dose and aimed at the toxicity of TMS for tilapia were run under a 24 hour and 96 hour time frame. The results show that the LD50 for 24 hour and 96 hour exposure were 79.23 ppm and 78.06 ppm respectively. This indicates that under the longer the exposure, the concentration for LD50 decreases. The methodology used to examine the residue of an eight hour long exposure to 30 ppm of TMS was HPLC. HPLC is the method of using McIIvaine buffer (0.1 M citric acid/ 0.2 M disodium hydrogen phosphate, 1：1) for extraction, then filtered through C18 cartridges, and set with ultraviolet detector at a wavelength of 220 nm. The results indicate that such a method is both accurate and precise, plus it also has a minimum detection limit of 0.01 ppm. TMS residues in serum, liver, and muscle of tilapia are under the minimum detection limit after 48, 192, and 24 hours respectively. This study, in addition to the establishment of the necessary reference tilapia clinical doses of different applications, the detection method can be effectively applied to the tilapia fish tissue residues or relevant aquatic products for the detection of TMS.
|
|---|
