长期施用粪肥菜地土壤中四环素类抗生素的含量与分布特征

规模化养殖场动物粪肥富含抗生素且作为有机肥大量施用于农业生产，由此造成的土壤抗生素污染问题在我国还鲜有研究.针对亚热带地区长期施用粪肥的“无公害蔬菜”生产基地，利用固相萃取-高效液相色谱-串联质谱(HPLC-MS/MS)分析方法，探讨了土壤中4种四环素类(TCs)化合物(四环素、土霉素、金霉素、强力霉素)的含量与分布特征.结果表明，土壤中4种四环素类化合物的总含量(TCs)在1.35～22.52 μg/kg之间，平均为7.35 μg/kg.各化合物的检出率在31%～100%之间，平均含量为0.63～3.11 μg/kg，以土霉素和强力霉素为主.化合物的含量与组成特征无论在平面上还是在剖面上均存在明显的空间分布差异，且随着深度增加含量迅速降低，但在80 cm深度仍有检出.土壤中四环素类化合物的含量较低，生态毒性风险较小,但化合物的检出率较高且普遍同时检出多种化合物，其协同生态毒性尤其是耐药性问题值得进一步研究.

Concentrations and Distribution of Tetracycline Antibiotics in Vegetable Field Soil Chronically Fertilized with Manures

Occurrence of antibiotics in the soils substantially fertilized with antibiotics-enriched animal manures is very of concern. This paper investigated the concentration and distribution of four tetracycline antibiotics in soils from vegetable field chronically fertilized with manures in subtropical area using solid-phase extraction followed by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-MS/MS). The sum concentrations of four tetracycline compounds ranged from 1.35 microg/kg to 22.52 microg/kg with an average of 7.35 microg/kg. There were thirty one to one hundred percent of the soil samples were detected with average concentrations of 0.63- 3.11 microg/kg for four tetracycline compounds which dominated mostly with oxytetracycline and secondly with deoxytetracycline. Composition and levels of tetracycline compounds varied obviously in both horizontal and vertical soils. The concentration of tetracycline compounds in soil profile decreased rapidly with the depth and some of the compounds were still detected in 60 to 80 centimeter depth of soil. It is concluded that tetracycline antibiotics in soils from vegetable field chronically fertilized with manures in subtropical area were generally lower and less ecotoxic risk for soil ecosystem. But it should not be ignored in view of combined toxic effect and resistance of various compounds.