中文摘要：

为了研究抗生素在天然水体中的固、液相分配规律,分析了水体中颗粒物对7种典型抗生素的吸附特征,并通过环境扫描电镜测定了颗粒物的表面结构及元素组成.同时,采用高效液相色谱与质谱串联（HPLC-MS/MS）的检测方法对抗生素进行测定,以Simeton为内标物,得到抗生素的检出限为15~25 ng·L-1,定量下限为50~83 ng·L-1.连续吸附实验结果表明：初始的20 min颗粒物对抗生素的吸附比较快,达到过量吸附;吸附达到过饱和后会进行10 min的解吸反应;实验进行30 min后,吸附与解吸过程的变化会趋于稳定,2 h后达到吸附平衡.抗生素的平衡吸附量在1616~15568 ng·g-1之间,其吸附量及吸附曲线的变化与抗生素的pKa值密切相关.

英文摘要：

In order to investigate the distribution of antibiotics between the truly dissolved and the non-aqueous phases in nature water,the adsorption of 7kinds of typical antibiotics on the surface of the particles was analyzed. Environmental scanning electron microscopy（ESEM） was used to examine the surface structure and elements of aquatic particles. A high performance liquid chromatography tandem mass spectrometry（HPLC-MS /MS） method was developed for simultaneous determination of 7 antibiotics. Simeton was used as an internal standard. The limit of detection（LOD） of 7 compounds ranged from 15 ng·L-1to 25 ng·L-1 and the limit of quantification（LOQ） ranged from 50 ng·L-1to 83 ng·L-1. The continuous adsorption experiments show that adsorption of antibiotics on particles is fast,even to the excess adsorption in the initial 20 minutes; the desorption reaction lasts for 10 minutes after the adsorption saturation; after 120 min,the adsorption and desorption variations tend to be stable. Equilibrium adsorption capacity of antibiotics by particles is between 1616 ng·g-1and 15568 ng·g-1. The adsorption amount and adsorption curve changes with antibiotics is closely related to pKaof the antibiotics.