Department of Inorganic Chemistry, Faculty of Pharmacy, Medical University of Gdansk, Al. Hallera 107, 80-416 Gdansk, Poland.
Chemosphere. 2014 Jan;95:281-8. doi: 10.1016/j.chemosphere.2013.09.012. Epub 2013 Sep 29.
Pharmaceuticals are emerging contaminants in the natural environment. Most studies of the environmental fate of these chemicals focus on their behavior in wastewater treatment processes and in sewage sludge. Little is known about their behavior in soils. In this study adsorption and biodegradation of four antidiabetic pharmaceuticals - glimepiride, glibenclamide, gliclazide and metformin - were examined in three natural soils. The sorption of sulfonylurea derivatives was high (higher than sulfonylurea herbicides for example), whereas metformin showed high mobility. Desorption rates were highest for metformin. Sorption isotherms in two of three soils fitted best to the Freundlich model. Despite their high affinity to for soil surfaces, biodegradation studies revealed that transformation of the drugs occurred. Biodegradation results were described by pseudo-first order kinetics with half-life values from 5 to over 120 d (under aerobic conditions) and indicate that none of the tested drugs can be classified as quickly biodegradable. Biodegradation under anoxic conditions was much slower; often degrading by less than 50% during time of the experiment.
药品是自然环境中的新兴污染物。大多数关于这些化学物质在环境中归宿的研究都集中在它们在废水处理过程和污水污泥中的行为。关于它们在土壤中的行为，人们知之甚少。在这项研究中，四种抗糖尿病药物——格列美脲、格列本脲、格列齐特和二甲双胍——在三种天然土壤中的吸附和生物降解情况进行了研究。磺酰脲类衍生物的吸附性很高（高于磺酰脲类除草剂等），而二甲双胍的移动性较高。对于二甲双胍，解吸率最高。在三种土壤中的两种土壤中，吸附等温线最符合 Freundlich 模型。尽管这些药物对土壤表面具有很高的亲和力，但生物降解研究表明，这些药物发生了转化。生物降解结果用一级动力学方程描述，半衰期值从 5 天到超过 120 天（在有氧条件下），这表明测试的药物均不能被归类为快速生物降解。在缺氧条件下的生物降解速度要慢得多；在实验期间，通常降解不到 50%。
