东莞市蔬菜基地多环芳烃的污染特征研究

Occurrence of polycyclic aromatic hydrocarbons(PAHs) in vegetable fields of Dongguan city

利用气相色谱-质谱技术分析了东莞市典型蔬菜基地灌溉水、土壤和蔬菜中属于美国国家环保局优控污染物的16种多环芳烃(PAHs)化合物的污染特征。结果表明,灌溉水中仅检出少数PAHs化合物,且含量较低。土壤和蔬菜中均检出14种PAHs化合物,其中土壤中PAHs化合物总含量在0.048～1.799mg/kg之间,主要化合物为菲和芘,部分化合物超过美国土壤控制标准;蔬菜中ΣPAHs在0.174～3.261mg/kg(干重)之间,多数低于1.0mg/kg。大部分蔬菜中检出5种以上PAHs化合物,含量以低于0.50mg/kg为主,主要化合物为芘、菲、萘、蒽和荧蒽。致癌性化合物苯并(a)芘、苯并(b)荧蒽和苯并(k)荧蒽的检出率较低但含量高达1.0mg/kg左右。因此,东莞市蔬菜基地已受到PAHs不同程度的污染。

Sixteen polycyclic aromatic hydrocarbons （PAHs）classified as U.S EPA priority pollutants in irrigating water, soils and vegetables sampled from nine typical vegetable fields of Dongguan City were detemined by gas chromatography-mass spectrometry （GCMS）. Only a few PAH compounds with low concentrations were detected in irrigating water. Fourteen PAH compounds were detected in both soils and vegetables. The total concentrations of the PAH compounds composed mainly of phenanthrene and pyrene in soils range from 0.048 to 1.799 mg/kg. The concentrations of some PAH compounds exceed US soil control standards. More than five PAH compounds consisting mainly of pyrene, phenanthrene, anthracene, anthracene and fluoranthene were detected in most vegetable samples, which predominats under 0.50 mg/kg.The total concentrations of the PAH compounds （ΣPAHs） in vegetables range from 0.174 to 3.261 mg/kg, which predominats under 1.0 mg/kg. It is concluded that soil and vegetables in vegetable fields of Dongguan City were polluted with polycyclic aromatic hydrocarbons.