Objective To study the toxicokinetics of Cymermethrin and its metabolites in dog bile and provide evidence for forensic cases of identification of Cymermethrin poisoning. Methods 1/4LD50 doses of Cymermethrin were given to 6 male dogs by oral perfusion after the gallbladder fistula surgery on them,and their bile were collected at different time, in which Cymermethrin and its metabolites were extracted by Liquid-liquid extraction with dichloromethane and detected by HPLC-MS-MS. The qualitative analysis was based on retention time and MRM ions. The quantitative analysis was based on an internal standard method and calibration curve. Toxicokinetics equations of Cymermethrin and its metabolites in the bile were established from the c-t curves which were fitted by the WinNonlin toxicokinetics software meanwhie toxicokinetics parameters were obtained. Results The toxicokinetics of Cymermethrin met first-order dynamic equation. The Tmax of Cymermethrin(CYM), 3-phenoxybenzoic acid (3-PBA), 3-(2,2-Dichloroethenyl)-2,2-dimethyl-cyclopropanecarboxylate (DCVA) respectively were 1.52±0.30,1.29±0.04,0.93±0.41 h ; The Cmax of CYM, 3-PBA, DCVA respectively were 0.38±0.03,7.9±1.32,30.9±16.24 μg/mL ; The T1/2 of CYM, 3-PBA, DCVA respectively were3.93±0.71,1.36±0.11,4.49±2.81 h; Conclusion The toxicokinetics of Cymermethrin in dog bile met first-order dynamic equation ; The toxicokinetics model and parameters of Cymermethrin can provide evidence for forensic identification of Cymermethrin poisoning cases.

Objective Study on the stability of carbofuran and its metabolite carbofuran phenol in blood preserved at different conditions,in order to provide a scientific evidence for forensic identification of carbofuran poisoning death. Methods The dogs were given intragastric administration with 4LD50(13.5mg/kg) of carbofuran, the blood were collected and divided into five equally groups preserved at 20℃(NC2.5mg/mL), 20℃(1%NaF), 20℃, 4℃ and -20℃, respectively. The concentrations of carbofuran and carbofuran phenol in above samples were detected by GC-MS/MS with MRM at 0d、5d、7d、15d、40d、83d and 150d. Results The concentration of carbofuran in preserved blood were found to be significant decrease at 7d(P < 0.05), then a steady decline. In each condition, the concentration of carbofuran phenol in preserved blood showed an increasing trend firstly, then a declined tendency. The concentration of carbofuran and carbofuran phenol descending fast in blood at 20 ℃ (NC) and 20 ℃ (1%NaF).Conclusion Carbofuran and carbofuran phenol in preserved specimens are found to be decomposed. The decomposition is quick at 20℃ and slow at -20℃. Citrate sodium and sodium fluoride are not suit for anticoagulation and antiputrefactiva. Biological specimens used for forensic identification of the carbofuran poisoning should be stored at refriferated or freezed, and be analyzed as soon as possible.

Objective To develop a method of support liquid-liquid extraction (SLE) and simultaneous determination of 4 components in somedon and its 8 metabolites by GC–MS/MS. Methods Somedon and its metabolites were extracted by SLE and determined by GC-MS/MS in MRM mode. The qualitative analysis was based on retention time and ratio of ions. The quantitative analysis was based on internal standard method and calibration curve. Results After SLE and determination of 4 components in somedon and its 8 metabolites, the extraction rate were 37.57%~95.87%, the linear range were 0.12μg/mL~16.00μg/mL, the correlation coefficient(r)were 0.989 6~0.999 7, LOD were 0.08ng/mL~14.48ng/mL, the accuracy were 79.63%~122.90%, the interday and intraday precision were 0.99%~7.43% and 2.19%~10.60% respectively. Conclusion Simultaneous determination of somedon and its metabolites by GC–MS/MS in biological samples, which was rapid, simple, accurate and was high precision and recovery, can be used for qualitative and quantitative analysis in forensic cases.