Reversible interactions between drugs and humic acid in water can be an important factor in determining the bioavailability and effects of these pharmaceuticals as micropollutants in the environment. In this study, microcolumns containing entrapped humic acid were used in high-performance affinity chromatography (HPAC) to examine the binding of this agent with the drugs tetracycline, carbamazepine, ciprofloxacin, and norfloxacin. Parameters that were varied to optimize the entrapment of humic acid within HPLC-grade porous silica included the starting concentration of humic acid, the mass ratio of humic acid vs silica, and the method of mixing the reagents with the support for the entrapment process. The highest retention for the tested drugs was obtained when using supports that were prepared using an initial humic acid concentration of 80 mg mL⁻¹ and a humic acid vs silica mass ratio of 600 mg per g silica, along with preincubation of the humic acid with hydrazide-activated silica before the addition of a capping agent (i.e., oxidized glycogen). Characterization of the humic acid support was also carried out by means of TGA, FTIR, SEM, and energy-dispersive X-ray spectroscopy. The binding constants measured by HPAC for the given drugs with entrapped Aldrich humic acid gave good agreement with values reported in the literature under similar pH and temperature conditions for this and other forms of humic acid. Besides providing valuable data on the binding strength of various drugs with humic acid, this work illustrates how HPAC may be used as an analytical tool for screening and characterizing the interactions of drugs and man-made contaminants with humic acid or related binding agents in water and the environment.

药物与水中腐殖酸之间的可逆相互作用可能是决定这些药物作为环境微污染物的生物利用度和作用的重要因素。在这项研究中，含有包埋腐殖酸的微柱被用于高效亲和色谱 (HPAC) 以检测该试剂与药物四环素、卡马西平、环丙沙星和诺氟沙星的结合。为优化 HPLC 级多孔二氧化硅内腐植酸的包埋而改变的参数包括腐植酸的起始浓度、腐植酸与二氧化硅的质量比，以及将试剂与包埋过程支持物混合的方法。当使用初始浓度为 80 mg/mL 的腐殖酸制备的支持物时，获得了测试药物的最高保留⁻¹腐殖酸与二氧化硅的质量比为 600 mg/g 二氧化硅，同时在添加封端剂（即氧化糖原）之前将腐殖酸与酰肼活化二氧化硅进行预孵育。还通过 TGA、FTIR、SEM 和能量色散 X 射线光谱法对腐殖酸载体进行了表征。对于含有 Aldrich 腐植酸的给定药物，通过 HPAC 测量的结合常数与文献中针对这种和其他形式的腐植酸在类似 pH 和温度条件下报道的值非常吻合。除了提供有关各种药物与腐植酸结合强度的宝贵数据外，