珠江广州河段沉积物中典型抗生素的污染特征

Occurrence of Typical Antibiotics in Sediments of Guangzhou Section of the Pearl River

采用乙腈/柠檬酸缓冲液超声提取沉积物中的抗生素,并以固相萃取法富集和净化萃取物,以高分离度快速液相色谱/质谱(SPE-RRLC-MS/MS)进行测定,研究了珠江广州河段13个采样点41种目标抗生素的质量分数水平和时空分布特征.结果表明,珠江广州河段沉积物在枯水期或丰水期共有24种抗生素被检出,枯水期和丰水期质量分数范围分别为ND(未检出)~54.800μg/g和ND^3.433μg/g,两季质量分数最高的抗生素均为氧四环素;沉积物中氟喹诺酮类和四环素类抗生素占比较高;在枯水期总抗生素质量分数整体上高于丰水期,抗生素的质量分数在珠江广州河段沉积物中空间分布整体上呈现人口密集城区河涌>人口密集城区航道>航道中下游>航道上游,与广州市区产污排污的分布状况基本一致.

Extraction of sediment samples was carried out with an ultrasonic method using a mixture of acetonitrile and citric buffer as the extraction solution. The extracts of the solid samples were then cleanedup and enriched with a tandem solid phase extraction（SPE） method,followed by an analysis using rapid resolution liquid chromatography-tandem mass spectrometry（RRLC-MS/MS）. A study of the occurrence and special distribution of 41 antibiotics from 13 sampling sites in sediments of Guangzhou section of the Pearl River was conducted. The results showed that 24 antibiotics were detected in the sediments of Guangzhou section of the Pearl River in dry and wet season.The concentrations in dry season and wet season were at the range of ND（not detected） - 54.800 μg/g and ND -3.433 μg/g respectively,and the antibiotics of the highest content in the two seasons were both oxytetracycline. In sediments,the predominant antibiotics were fluoroquinolones and tetracycline antibiotics. The total antibiotic concentration in dry season was higher than that in wet season. The spatial distribution of antibiotics in the sediments of Guangzhou section of the Pearl River followed the order： streams in densely populated urban area〉 the river reaches in densely populated urban area 〉middle and lower reaches of the river 〉the upstream of the river,which is basically the same as the distribution of pollution and sewage in the urban area of Guangzhou.