外切酶保护PCR快速检测垃圾焚烧飞灰中二噁英类化合物

目的]利用外切酶保护PCR分析(exonuclease protection mediated-PCR assay，EPM-PCR)方法检测焚烧炉飞灰中的二噁英类化合物(dioxins-like chemicals，DIEs)的毒性当量(toxic equivalency quantifies，TEQs)。方法]将两份5g飞灰样品经过抽提、浓缩及纯化等前处理步骤后，采用EPM-PCR方法检测其中的二噁英类化合物的TEQs。与高分辨气相色谱-质谱联用技术(high-resolution chromatography combined with high-resolution mass spectrometry，HRGC-HRMS)检测结果相比较，分析其差异原因。结果]两份垃圾焚烧飞灰样品TEQs值分别为1288ng／kg和160130ng／kg，相当于根据HRGC-HRMS检测结果估算出来的TEQ值的1．61倍和2．63倍。EPM-PCR检测TEQ值偏高可能由于检测物中包含一些被化学方法排除的物质(如多氯联苯)造成。结论]结合有效的前处理过程，EPM-PCR可快速地用于实际样品的定性与定量检测。

The Determination of Dioxin-like Chemicals in Fly Ash Samples Using Exonuclease Protection Mediated-PCR Assay

Objective] Exonuclease protection mediated-PCR(EPM-PCR) assay was applied to detect the toxic equivalency quantities(TEQs) of dioxin-like chemicals( DLCs) in fry ashes from incinerators. After the extraction, concentration and purification,5 g samples were analyzed by EPM-PCR assay. Results] The TEQs of two samples were 1 288 ngTEQ/kg and 16 000 ngTEQ/kg respectively. Compared with those of the high-resolution chromatography combined with high-resolution mass spectrometry (HRGC/HRMS) method, the values were 1.61 and 2.63 times higher. The reason may be the presence of interference chemicals which are not detected by HRGC/HRMS,such as PCBs. Conclusion] With the valid pretreatment process,EPM-PCR assay is valuable to screen and quantify the DLCs in samples rapidly.