Optimization Of Purification Methods For Pbdes Determination In Environmental Samples And The Influence Of Organic Fertilizer On Its Transportation From Soil To Plant

Polybrominated diphenyl ethers(PBDEs)as a class of persistent organic pollutants(POPs)are widespread in the environment.PBDEs are the key control chemicals of Stockholm convention and their chemical properties are very stable.PBDEs are ressistant to degradation,easy to adsorb in the particulate matters and sediments,and can conduct a long-term migration.The safety,stability and diversity of soil ecosystem will be impacted seriously.The soil pollution is difficult to improve due to its hysteresis,concealment and accumulative properties.Preventing and controlling the soil organic pollution,protecting the soil environment and realizing the sustainable use of the soil are a hotspot in the world.They can migrate to the plants through the contaminated soil,and then by the plant intake,the food chain cause a serious damage to the animal and human health.Therefore,it is significant to explore to establish an agronomic regulation pathway to prevent and control the migration of organic pollutants to plants.At present,the detection technology of PBDEs has been basically mature,but the preparation technology of PBDEs is still constantly optimized.Due to the complex composition of environmental samples,it is significant to optimize the extraction and purification technology of PBDEs in the environmental samples and to establish the high sensitivity analysis method of PBDEs.This paper carried out laboratory experiments and greenhouse cultivation experiments,established and optimized the determination methods of PBDEs in soil,in plant and in earthworm.Furthemore,the conventional organic fertilizer,the microbial organic fertilizer and the cornstalk were used to explore the passivation and activation mechanism of PBDEs and to explore the migration mechanism from soil to plants.The main research results are as follows:1.An optimized method was established for the determination of 10 Polybrominated diphenyl ethers(PBDEs)in soil using Accelerated Solvent Extraction(ASE),Solid Phase Extraction(SPE)and gas chromatography with an electron capture detector(GC-ECD).ASE was used to obtain 10 PBDEs in soil and a good extraction system had been investigated.The purification of 10 PBDEs in the soil solution was completed by SPE.The optimized conditions can be acquired when using a n-hexane:acetone(V:V,4:1)system to extract and an acid silica gel column to purify.Under the optimized conditions,the average recoveries of 10 PBDEs in soil ranged from 85.42-103.08%with the RSDs of 1.74-4.62%.Method detection limits(MDLs)were 0.04-0.22 ng/mL.The method is simple,rapid and efficient,which has been successfully applied to determine 10 PBDEs in the contaminated soil.2.An optimized method was established for the determination of 10 Polybrominated diphenyl ethers(PBDEs)in plant using Accelerated Solvent Extraction(ASE),Solid Phase Extraction(SPE)and gas chromatography with an electron capture detector(GC-ECD).ASE was used to obtain 10 PBDEs in plant and a good extraction system had been investigated.The purification of 10 PBDEs in soil solution was completed by SPE.The optimized conditions can be acquired when using n-hexane:acetone(V:V,4:1)system to extract and acid silica gel column to purify.Under the optimized conditions,the average recoveries of 10 PBDEs in soil ranged from 75.34-91.54%with the RSDs of 0.72-2.57%.Method detection limits(MDLs)were 0.04-0.22 ng/mL.The method is simple,rapidand efficient,which has been successfully applied to determine 10 PBDEs in plant.3.An optimized method was established for the determination of 10 Polybrominated diphenyl ethers(PBDEs)in earthworm using Accelerated Solvent Extraction(ASE),Solid Phase Extraction(SPE)and gas chromatography with an electron capture detector(GC-ECD).ASE was used to obtain 10 PBDEs in earthworm and a good extraction system had been investigated.The purification of 10 PBDEs in soil solution was completed by SPE.The optimized conditions can be acquired when using n-hexane:acetone(V:V,4:1)system to extract and Al2O3-Florisil column to purify.Under the optimized conditions,the average recoveries of 10 PBDEs in soil ranged from 82.91-95.12%%with the RSDs of 1.14-8.52%.Method detection limits(MDLs)were 0.04-0.22 ng/mL.The method is simple,rapidand efficient,which has been successfully applied to determine 10 PBDEs in earthworm.4.The influence of organic fertilizer on its transportion from soil to plant was explored.Manuring of organic fertilizer can increase the concertration of organic matter,total N,total P and total K,meanwhile,can increase the yield of carrot.The edible part of carrot increased 36.84%.Manuring of conventional organic fertilizer,microbial organic fertilizer and cornstalk can effectively prvent and control the migration of PBDEs from soil to shoots.The influence factors of PBDEs migration from soil to plant are the type and applied quantity of organic fertilizers.Root absorbing is the main way of PBDEs migration from soil to plant;Reducing PBDEs concentration of the soil solution in the root domain,slowing PBDEs migration in the interface of soil(soil solution)-root are the key to prevent and control the PBDEs migration.