Study On Plant Absorption And Accumulation Of Organophosphates In Soil

Organophosphates(OPEs)are widely used as a new type of flame retardant,instead of the original bromine flame retardant.Studies have suggested that OPEs is widespread and potentially toxic in the environment,and is therefore of widespread concern.In this study,rapeseed,which is often eaten in daily life,was selected as the research object to study the absorption and accumulation characteristics,distribution and toxic effects of rapeseed on tri(2-chloroisopropyl)ester(TCPP)under the pollution of TCPP.The main research results are as follows:(1)The analytical method of organophosphate in plants was established.Florisil was selected as dispersant,acetone: n-hexane(1:1,V /V)as an extraction solvent for solid phase extraction.After the solution volume was determined by tr-5ms(30 m×0.25 m ×0.25mm),the target compound was qualitatively determined by reaction monitoring mode(SRM),retention time and characteristic ions,and quantified by internal standard method.The OPEs analysis method developed in this study has a good linear relationship.The correlation coefficients r were all greater than 0.9915,the detection limit of the method was 0.05~0.33ng/g,and the quantitative limit of the method was 0.16~1.10 ng/g.The recoveries of 13 OPEs were 65.1%~109.1%(2 ng),68.4%~103.9%(20 ng),and 70.2%~105.3%(100 ng),respectively.The relative standard deviation of the experiment is less than 15%,which meets the requirements of quantitative analysis.(2)TCPP stress experiment in different growth periods showed that TCPP could inhibit the growth of rapeseed roots.Under the stress of low concentration(100 ?g/kg),TCPP promoted the growth of plants and increased the activity of three kinds of antioxidant enzymes(SOD?POD?CAT)and chlorophyll content in rapeseed leaves.The treatment of 500 ?g/kg TCPP could promote the growth of rapeseed in the mature stage,but had no obvious effect on the growth of rapeseed in the growing stage.Under the stress of high concentration(1000 ?g/kg),the growth of rapeseed was inhibited.The activity of three kinds of antioxidant enzymes(SOD?POD?CAT)and the content of chlorophyll in the leaves of rapeseed showed a decreasing trend compared with the low concentration.The content of proline and MDA increased with the increase of TCPP concentration.(3)The accumulation of TCPP in rapeseed was similar in different growth periods.TCPP was mainly accumulated in the leaves of rapeseed,and the content in the roots of rapeseed was higher than that in the stems.The content of TCPP(water soluble state,acid soluble state and combined state)in soil is Combined state > water soluble state > acid soluble state.The effective TCPP state(water soluble state?acid soluble state)can be absorbed and accumulation by rape.Therefore,The reduction of TCPP in soil was much greater than the total amount of TCPP accumulated in rape,the effective state reduction of TCPP in soil was mainly concentrated in the growth period of rape.