Comparative Studies on Toxicokinetics and Residues of Dimethyl Phthalate (DMP) in Tilapia(Oreochromis niloticus × O. aureus)at Different Water Temperatures

The study was conducted to evaluate the toxicokinetic disposition and residue of Dimethyl phthalate (DMP) in tilapia at different water temperatures (18oC and 28oC) by RP-HPLC method. After oral administration of DMP with a single does of 20mg/kg body weight, the tilapia’s plasma, muscle, brain, skin and myocardium were sampled separately at different time to determine the concentration of DMP. Then the data were analyzed using 3p97 Pharmacokinetics software written by the Chinese Society of Mathematical Pharmacology, which indicated that the absorption, distribution and elimination half-life at 28oC were 0.020 h, 0.19 h and 40.16 h, while the absorption half-life and elimination half-time were 3.01 h and 57.62 h at 18oC. That’s to say, the DMP absorption rate was faster in tilapia at 28oC than that at 18oC. And the serum concentration-time curve (AUC) was 30.13μg h ml at 28oC, while the T-peak was 0.074 hrs and the C-peak were 2.06μg·ml; whereas, the corresponding situations at 18oC were 74.77 μg·h·ml, 13.51 hrs and 0.76μg·ml, respectively. No matter how, the DMP residue was detected after oral administration for 360 hrs at both water temperatures, but the research had revealed that water temperature had great impact on the DMP absorption, distribution and elimination in tilapia.