Preparation Of Novel Needle Trap Devices And Their Applications For Analysis Of Trace Organic Pollutants

Polychlorinated biphenyls(PCBs)are a series of persistent organic pollutants,which have carcinogenic,teratogenic and mutagenic effects.Due to the widely used in industry,they have causing environmental pollution and do great harm to human health.Therefore,it is very necessary to develop a simple,highly sensitive and high-performance sample pretreatment and analysis method to detect PCBs.Needle trap device has the advantages of high enrichment factor,fast extraction rate,convenient operation and good stability,which is suitable for sample pretreatment of trace organic pollutants in complex matrix.In this paper,the preparation and application of the needle trap devices for polychlorinated biphenyls analysis was studied.Two coating materials were synthesized on the Zylon fiber by sol-gel technique.And the needle trap device was prepared by packing the fiber into the stainless steel needle.The prepared device has good stable performance and excellent extraction performance.It can be used for enrichment and detection of PCBs in environmental water samples and milk samples by hydrophobic effect and π-πinteraction.The specific research contents of this paper are as follows:1.The needle trap device was prepared by packing the sol-gel coating fiber into the stainless steel needle.Combined with gas chromatography,it was applied for analysis of five PCBs in environmental water samples.The high temperature resistant Zylon fiber coated with sol-gel solution was filled into the stainless steel needle to prepare the needle trap device,and the enrichment of PCBs was realized through hydrophobic effect.The coated fibers were characterized by scanning electron microscopy(SEM).The surface of the coated fibers was rough and the specific surface area increased.The factors affecting the extraction efficiency were optimized.The storage performance and service life of the coating fibers were investigated.After optimization,the linear range of PCB28,PCB52 and PCB118 was 0.02～500 μg/L,and the linear range of PCB153 and PCB180 was 0.05～500 μg/L,and the correlation coefficient(r)was 0.9937 and 0.9999.The limits of detection(S/N=3)was0.0021～0.01 μg/L and the limits of quantification(S/N=10)was 0.0069～0.033 μg/L.The concentration factors of five PCBs in the needle trap device ranged from 1150 to9537.The recoveries of PCBs spiked in Songhua River water were in the range of92.19%～98.56% and the RSDs were 1.8～12.8%.2.A coating fiber needle trap device was prepared by using sol-gel technique with graphene oxide(GO)as coating material.Combined with GC,it was used for the enrichment and detection of PCBs in milk samples.Scanning electron microscopy(SEM)showed that the surface of the coating fibers was rough and showed obvious wrinkle-like structure,which increased the specific surface area.Moreover,several main factors affecting the extraction efficiency were optimized,including the quality of adsorbent,extraction time and temperature,desorption temperature and time.Under the optimal experimental conditions,the proposed method has good linearity in the range of 0.02～500 μg/L(r>0.9908).The limits of detection and limits of quantification were 0.0028～0.0058 μg/L and 0.0093～0.019 μg/L,respectively.The RSDs of run-to-run and needle-to-needle were lower than 3.84% and 5.54%,respectively.In addition,the storage capacity and service life of the device were investigated.The method was used to detect five kinds of PCBs in milk samples.The spiked recoveries were 92.20%～98.93% with RSDs lower than 9.0%.The needle trap device has the advantages of simple preparation,good service life and good stability,and can be used for the analysis of PCBs in milk samples.