Environmental Pollution Chemistry On Organochlorine Pesticide Residues At Sediment-Water Interface Of Bohai Bay

Intertidal zone is an intense sea-land interaction interface and the sedimentationof coastal sewage discharge as well as pollutants carried by rivers makes it be one ofthe most important destination of organochlorine pesticides (OCPs). Besides thedirect effect on human health, organic pollutants in intertidal zone will meanwhileresult in "secondary pollution" of OCPs under the action of tides, waves and marineorganisms, and thus bringing about certain hazard on costal environment. Under thejoint financial supports from the National Natural Science Foundation of China (Grant40573044) and Scientific Research Foundation for Distinguished Professor of Tianjin(Grant20100405), an accurate, rapid and higher sensitive method for eightorganochlorine pesticide residues in sediment and porewater including BHC series(α-BHC, β-BHC, γ-BHC, δ-BHC) and DDT series (p, p’-DDT, o, p’-DDT, p, p’-DDEand p, p’-DDD) by gas chromagraphy (GC) after enrichment and purification withsolid-phase microextraction (SPME) was established and then successfully applied forthe determination of OCPs in sediments and porewater of intertidal zone of Bohai Bayand estuary of Yongding River. Meanwhlie, the profiles of OCPs in sediment andporewater of these areas were also presented.Conclusions presented in this study can be summarized as follows:①The optimum SPME-GC conditions for OCPs analysis were established bythe optimization of SPME-GC.②The SPME-GC method for OCPs analysis in sediment samples wasestablished. The detection limits for eight OCPs ranged from0.0084~0.27ng/g, andthe recoveries of spiked samples were65.5~119.6%with RSD less than10.4%. Theresults were satisfied.③The SPME-GC method for OCPs analysis in seawater samples wasestablished. The detection limits for eight OCPs ranged from1.16~8.93ng/L, and the recoveries of spiked samples were65.5~119.6%with RSD less than10%. The resultswere satisfied.④OCPs contents in intertidal sediments of Bohai Bay as well as sediments ofYongding River were analyzed. BHC and DDT series in intertidal sediments, whichare4.20,10.93ng/g and3.08,2.76ng/g respectively, are obviously higher than thesein estuarine sediments of Yongding River. BHC series in intertidal sediments mainlyexist in β-BHC form with an average content2.63ng/g, meanwhile the contentsincrease with depth. However, β-BHC in estuary basically doesn’t present an obviousvariation trend. The contents of DDT series in intertidal zone increase with depth.However, the trend for estuarine sediments is just the opposite.⑤OCPs contents in porewater of intertidal sediments of Bohai Bay and estuarysediments and porewater of sediments of Yongding River were analyzed. OCPs ofBohai Bay are higher than these in estuary. OCPs contents in porewater of intertidalsediments of Bohai Bay and porewater of sediments of Yongding River are0.51,0.38μg/L. DDT series in porewater of intertidal sediments are relatively higher with anaverage content reaching to0.18μg/L, and it is far higher than that in nationalseawater quality standard to cause certain effects on marine environment. Meanwhile,there still have some new input of DDT series in recent years, which should arousethe attention of departments concerned.