牡蛎和贻贝中二噁英及多氯联苯同类物的分布

Distributions of PCDD/Fs and PCBs congeners in oysters and marine mussels

利用同位素稀释、高分辨气相色谱-高分辨质谱联用仪,首次测定了大连湾牡蛎和贻贝等海洋生物体内痕量的二噁英和多氯联苯,并比较了二噁英及多氯联苯的同类物在牡蛎和贻贝中的含量分布。结果表明,所采集的牡蛎和贻贝样品中均含有二噁英和多氯联苯,且多氯联苯的含量明显高于二噁英,反映出环境中多氯联苯背景值大于二噁英的背景值。其中,牡蛎和贻贝中二噁英总质量分数平均值分别为47.8pg/g和216pg/g(以干物质计),毒性当量平均值分别为0.89pg/g和0.87pg/g;12种有毒性的共平面多氯联苯的总质量分数平均值分别为585.5pg/g和818.6pg/g,总毒性当量平均值分别为0.47pg/g和1.18pg/g。牡蛎和贻贝样品中的二噁英及多氯联苯的同类物含量分布基本类似,表明二者摄取的二噁英及多氯联苯可能有相似的来源。可以把牡蛎和贻贝作为生物标志物,以监测海洋环境中二噁英和多氯联苯的污染状况。

Trace polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) in oyster and marine mussel samples collected from Dalian Bay were determined for the first time by isotope dilution and high resolution gas chromatography- high resolution mass spectrometry (HRGC-HRMS). The results showed that PCDD/Fs and PCBs exist in both oyster and marine mussel samples, and the concentrations of PCBs were higher than those of PCDD/Fs obviously. This indicated that the background concentrations of PCBs were higher than those of PCDD/Fs in the environment. The average total concentrations of PCDD/Fs in oyster and marine mussel samples reached 47.8 pg·g-1 and 216 pg·g-1 (dry weight), respectively; and the average total toxic equivalency (TEQ) reached 0.89 pg·g-1 and 0.87 pg·g-1, respectively. OCDD, 2,3,7,8-TCDF and OCDF were the main congeners in oysters and marine mussels. The average total concentrations of coplanar PCBs in oyster and marine mussel samples were 585.5 pg·g-1 and 818.6 pg·g-1, respectively, and the average W-TEQ values were 0.47 pg·g-1 and 1.18 pg·g-1, respec- tively. PCB#118, PCB#105, PCB#77, PCB#156 and PCB#123 were the main congeners in oysters and marine mussels. In samples, the PCDD/Fs and PCBs congeners which came from their ingested foods and the growing environment may have the same emission sources because the congener concentration distribution of PCDD/Fs and PCBs in all the determined samples was similar. Oysters and marine mussels can be used as bio-markers to survey the contamination status of PCDD/Fs and PCBs in the ocean environment.