| Objective: 1. To establish postmortem distribution models in rats and dogs; To establishdecomposition kinetics models with preserved specimens and buried cadaver of dogs.2.To investigate the postmortem distribution of carbofuran in rabbits and dogs;To study thedecomposition kinetics of carbofuran in preserved specimens and buried cadaver of dogs.3.To provide a scientific evidence for the forensic identification of carbofuran poisoning death.Methods:1.Postmortem distributionTwelve male wistar rats were randomly allocated to 2LD50 and 4LD50 groups, which weregiven an intragastric administration of carbofuran with a dose of 22 mg/kg and 44 mg/kg. Assoon as the vital signs disappeared, the rats were dissected and the specimens such as heartblood,heart,liver,spleen,lung,kidney,brain,were sampled immediately for the determination ofcarbofuran. The concentration of carbofuran was detected qualitatively and quantitative byGC/MS and GC/NPD.Nine dogs were randomly allocated to three groups, which were given an intragastricadministration of carbofuran with a dose of 4LD50. Then the toxic symptom were observed.Three groups of animals were dissected separately at the time of promptly death, disposed 1d ,7d at room temperature.The specimens such as heart blood, bile,vitreous humor, right upper limbmuscles, the right lower limb muscles,chest muscle, heart, liver, spleen, lung, kidney, brain,stomach were sampled immediately, in which the concentration of carbofuran was detectedqualitatively and quantitative by GC/MS and GC/NPD.2. The decomposition kinetics in preserved specimens2.1 decomposition kinetics of carbofuran in preserved specimen of poisoned dogs:Six dogs were given an intragastric administration of carbofuran with a dose of 4LD50. Thenthe toxic symptom were observed. As soon as the blood pressure, respiration and ECGdisappeared, the dogs were dissected, and the specimens of blood and liver were sampled anddivided into three portion separately preserving at 20℃,4℃,-20℃,in which carbofuran wasdetected qualitatively and quantitative by GC/MS and GC/NPD at 0 h, 1thd , 2thd, 3thd, 4thd, 7thd,after the preservation.Three dogs were given an intragastric administration of carbofuran with a dose of 4LD50 .Then the toxic symptom were observed. As soon as the blood pressure, respiration and ECG disappeared, the dogs were dissected, and the specimens of blood and liver were sampledimmediately. NaF was added to 1% in blood and liver was fixed in 4% formaldehyde. Thenpreserve the specimens at 20℃in which carbofuran was detected qualitatively and quantitativeby GC/MS and GC/NPD on 0h, 2thd, 4thd, 7thd.2.2 The decomposition kinetics of carbofuran in preserved cadaver blood:Added 80mgcarbofuran into 1000mL cadaver blood and then divide it to four part.Three of them werediposed at 20℃,4℃,-70℃and the other one at 20℃(1%NaF). The carbofuran and carbofuranphenol were detected qualitatively and quantitative by GC/MS on the0h,2d, 5d,8d, 32d, 64d,96d, 152d.3. The decomposition kinetics in buried cadavers.3.1 decomposition kinetics of carbofuran in buried cadavers: twelve dogs were given anintragastric administration of methamidophos with a dose of 4LD50. As soon as the bloodpressure, respiration and ECG disappeared, the dogs were put into plastic unsealed bags, andburied in the field in East Mountain, Taiyuan City. Three of them were dugged out, dissected andthe specimens were collected on the14thd, 40thd, 62thd after the burying.Carbofuran andcarbofuran phenol were detected qualitatively and quantitative by GC/MS.3.2 The effection of burial way on the decomposition kinetics of carbofuran in buried cadavers:nine dogs were given an intragastric administration of carbofuran with a dose of 4LD50. As soonas the blood pressure, respiration and ECG disappeared, the dogs were randomly allocated tothree groups and put into plastic unsealed bags, woven bags and wooden cases (coffins)respectively and buried in the field in East Mountain, Taiyuan City. They were dugged out,dissected and the specimen were collected on the 62d after the burying. Carbofuran andcarbofuran phenol were detected qualitatively and quantitative by GC/MS.3.3 The effection of poisonous dose on the decomposition kinetics of carbofuran in buriedcadavers: twelve dogs were randomly allocated to four groups and were separately given anintragastric administration of carbofuran with doses of LD50,2LD50,4LD50,8LD50. As soon as theblood pressure, respiration and ECG disappeared, the dogs were put into plastic unsealed bags,and buried in the field in East Mountain, Taiyuan City. They were dugged out, dissected and thespecimen were collected on the 62thd after the burying. Carbofuran and carbofuran phenol weredetected qualitatively and quantitative by GC/MS.Result:1.Animal performanceAfter the intragastric administration of carbofuran, the rats showed poisoning smptoms anddied after 30±10min.The poisoning smptoms were twitch,salivate,tear,wet hair,incontinence anddeath finally which were similar with organophosphorus pesticide. After the administration of carbofuran for 0.25±0.10h, the dogs showed poisoning smptomsand died after 1.0±0.5h. The poisoning smptoms were salivate,nausea,vomit,muscle beem tremor,twitch.2. GC and GC/MS detection3. Postmortem distribution3.1 The postmortem distribution of carbofuran in ratsThe concentration of carbofuran(LSD t-test, P<0.05) were as follows:(1) 2LD50 group:lung,liver>blood,brain,heart,kidney,spleen;(2)4LD50group:lung,liver,kidney> blood, heart, brain,spleen. The concentration of carbofuran in the organs full of blood such as lung and liver washigher than blood and other tissues with lowest in spleed. Carbofuran concentration in the organsof 4LD50 group was lower than that of 2LD50.3.2 The postmortem distribution of carbofuran in dogs and the stability in cadavers:The order of carbofuran concentration detected in poisoning death dogs was as follows:stomach＞blood,liver,lung＞spleen,heart,right forelimb,kidney,vitreous humor,brain＞breastmuscle, right hindlimb,bile (LSD-test,P<0.05). The order of carbofuran phenol concentrationwas stomach＞liver＞blood,heart＞spleed,kidney.It haven't been detected in other organs.Disposed by 1d and 7d,the concentration of carbofuran in blood, heart, liver, spleed, lung,kidney and stomach was not shapely reduced(T-test P＜0.05)and haven't been detected invitreous humor,muscle and brain.With the time,carbofuran phenol was detected in bile and lungin which it haven't been dectcted at the time of death. The concentration of carbofuran phenoldetected in stomach,liver,blood,heart,spleed and kidney showed a raised trend.4. The decomposition kinetics in preserved specimens4.1 Decomposition kinetics of carbofuran in preserved blood and liver of poisoning dogs.In each condition,the concentration of carbofuran detected in preserved specimens showed adescended trend. after stored by 7day,carbofuran haven't been detected in blood in eachpreserving condition and it could not be detected in liver ethier at the room temperature.Carbofuran concentation detected in preserved blood and liver at -20℃was descended slowerthan that at 20℃and 4℃(T-test,P＜0.05).the concentration of carbofuran detected in blood at20℃and 20℃(1％NaF)was separately decended to 63.9％and 49.5％of initial concentrationafter stored 2 day. And on the 4thd,it was 29.5％and 14.8％of initial concentration. theconcentration of carbofuran detected in liver at 20℃和20℃(4%formaldehyde)on the 2thd wasseparately decended to31.5％and 45.7％of initial concentration. On the 4thd,it was 2.8％and18.2％of initial concentration and in the 7th,it was 0％and 7.4％.4.2 The decomposition kinetics in preserved cadaver bloodIn each condition,the concentration of carbofuran detected in preserved cadaver blood showed a descend trend.At 20℃,4℃,-70℃and 20℃(1% NaF),carbofuran concentration detectedin preserved adaver blood descended significantly to 79.7％,72.6％,82.1％,79.5％of initialconcentration on 2th d, 2thd, 5th d, 2thd and on the 152thd, it descended to 22.9％,39.0％,62.3％,0％of initial concentration. The decomposition kinetics of carbofuran met the one compartmentopen model with a first order kinetics and could be described as CT=C0e-KeT. Decompositionhalf-lifes were 61.4d,135.3d,190.9d and150.3d at 20℃,4℃,-70℃and 20℃(1% NaF).Carbofuran phenol could be detected at 0h in preserved cadaver blood and the contentshowed a time-dependent rise trend (T-test, P＜0.05). In 20℃,4℃,-70℃and 20℃(1%NaF)condition,at 0h,the concent of cabofuran phenol was 2.06±0.39μg/mL and at 152thd,itincreased to 26.97±4.28μg/mL,25.47±8.88μg/mL,18.49±4.84μg/mL,15.99±3.00μg/mL appearently.5. The decomposition kinetics in buried cadaversCarbofuran content detected in buried cadavers of dogs showed a rise followed by a descendin the 153d.Except right forelimb and stomach,the concentration of carbofuran detected in theorgans except right forelimb and stomach increased to maximum on 14thd.Carbofuran haven'tbeen detected in right hindlimb,beast muscle,lung,brain on 40thd and in right forelimb,righthindlimb,beast muscle,liver,lung and brain on 62thd.On 153thd,only stomach could be detectedwith carbofuran and carbofuran phenol.Carbofuran phenol have been detected in blood,heart,liver,spleen,kidney , stomach at 0h andthe content showed a raised trend with the time. Carbofuran phenol have been detected in bloodon the 40thd and in right forelimb,stomach on the 62thd in which organs carbofuran haven't beeninspected.The research of different burial way showed on the 62thd,carbofuran could be detected inheart,spleen,kidney,stomach in the way buried by plastic bags,in kindney,stomach in the wayburied by woven bags and in stomach only in the way buried by wooden cases (coffins).On the 62thd ,the research of different poisonous dose showed : carbofuran and carbofuranphenol haven't been inspected in LD50 and 2LD50 dose group;carbofuran could be detected inheart,spleen,kidney and stomach with carbofuran phenol in right forelimb, heart,liver,spleen,kidney, stomach in the 8LD50 dose group;in the 8LD50 dose guoup,carbofuran couble bedetected in right hindlimb,heart,liver,spleen,kidney and stomach with carbofuran phenol in rightforelimb,right hindlimb,heart,liver,spleen,lung,kidney,brain and brain.Conclusion:1.The postmortem distribution, decomposition kinetics model of carbofuran(LD50, 2LD50,4LD50,8LD50,ig) in dogs have been developed, which can be applied to forensic identificationand study on forensic toxicokinetics of decomposition of carbofuran poisoning death case. 2. The developed GC-FPD and GC/MS analysis, of which recovery, linear range and sensitivitymeets the demand for analysis of poison in biological specimen, can be used in the forensicidentification and forensic toxicokinetics study of carbofuran poisoning death case.3.The concentration of carbofuran(LSD t-test, P<0.05) in poisoned rats were as follows:(1)2LD50group:lung,liver>blood,brain,heart,kidney,spleen;(2)4LD50group:lung,liver,kidney>blood,heart,brain,spleen.It prompts that we should draw materials reasonblely and analysecomprehensively in the forensic identification of carbofuran poisoning death case.The concentration of carbofuran detected in the poisoning dogs when immediately die wereas follows: stomach＞blood,liver,lung＞spleen,heart,right forelimb,kidney,vitreous humor,brain＞breast muscle, right hindlimb,bile (LSD-test,P<0.05). The order of carbofuran phenolconcentration was stomach＞liver＞blood,heart＞spleed,kidney.It haven't been detected in otherorgans. Disposed for 7d at room temperature,carbofuran and carbofuran phenol couble also bedetected in poisoning dogs.It prompts that carbofuran is metabolized fast,however it is stabilizein cadavers. In carbofuran poisoning death case, we shouble take bile, stomach, lung,spleen andliver but muscle, vitreous humor,brain for analysis in the forensic identification ofmethamidophos poisoning case.Carbofuran and carbofuran phenol should be taken at the sametime for determine the forensic identification.4.In different preserving condition,carbofuran can be decomposed in preserved blood, liver ofpoisoning dogs and in preserved cadaver blood.It was decomposed sharper in preserved blood,liver of poisoning dogs.On the 7thd,carborfuran couldn't be inspected in preserved blood of dogin any preserving condition.Also,it couldn't be detected in preserved liver at roomtemperature.carbofuran was decomposed slower in preserved cadaver blood. The decompositionhalf-lifes were 61.4d,135.3d,190.9d,150.3d at 20℃,4℃,-70℃,20℃(1%NaF).In the forensicidentification of carbofuran, Specimens shouble be stored at low temperature. Carbofuran andcarbofuran phenol should be detected at the same time.5. The decomposition kinetics of carbofuran in stored carbaver blood met the one compartmentopen model with a first order kinetics and could be described as CT=C0e-KeT. According to theequation,the theoretical value and measured value met well. The decomposition kinetic equationand parameter could be used to infer carbofuran content at the time of having the specimens.6.Carbofuran couble be decomposed in buried cadavers and the decomposing speed wasfast. .After buried for 153d,only stomach couble be detected with carbofuran and carbofuranphenol. Carbofuran content detected in buried cadavers of dogs except right forelimb andstomach showed a rise followed by a descend trend in the 153d and on the 14thd, increased tomaximum.Different buried way and different poisonous dose could affect great. In the forensicidentification of buried cadavers of carbofuran poisoning death,combined with the administration way of poison and antemortem treatment, the value and possibility of cadaver-dugging should beestimated according to the effection of buried time, buried way and poisonous dose ondecomposition of carbofuran. It should be carried out as soon as possible for Cadaver- dugging ,toxic analysis and qualitatively and quantitative analysis of carbofuran, carbofuran penol. Itcould be approximately estimated the carbofuran concentration range in buried cadaversaccording to the poision analysis and decomposition rule. |
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