基于分子印迹薄膜扩散梯度技术的痕量抗生素原位采样方法及应用研究

Diffusive gradients in thin films (DGT) as a passive sampling technique has been widely used in in-situ monitoring and bioavailability of metal ions; however, it is scarcely used for sampling of organic pollutants. The objective of this project is to prepare molecularly imprinted nanoparticles (MINP) with specific recognition, high capacity, and fast absorption, and design a binding phase based on the MINP for high efficient uptake of polar organic compounds and develop in-situ sampling method of trace antibiotics in waters based on DGT. In this study, several typical antibiotics which have been widely used and usually found in environments will be selected as analytes. Molecularly imprinted polymer film with a few tens of nanometers will be prepared on the surface of carbon nanomaterials to obtain molecular imprinting nanoparticles (MINP) by surface molecular imprinting technique based on reversible addition-fragmentation chain transfer (RAFT). Absorption characteristics of MINP for target antibiotics will be studied. Novel binding phase and related DGT sampling devices will be designed and prepared. Uptake performances of the binding phase for antibiotics and effect of pH, ionic strength, competitive compounds, and sampling time on the uptake performance of the binding phase will be investigated. Specific parameters about the DGT sampling devices with the binding phase and related sampling conditions will be studied, and a in-situ sampling method based on the DGT devices will be developed for trace antibiotics in waters. A comparison between DGT sampling and traditional sampling will be carried out through sampling and measurement of several typical antibiotics in different environmental waters to obtain the correlation between the results by the two methods. By this project, it is significant for improving the development of basic theory and technique of DGT for sampling of organic pollutants and also provides a technical platform for in-situ monitoring and bioavailability of organic pollutants.

薄膜扩散梯度技术（DGT）作为一种被动采样技术广泛用于金属离子原位监测和生物有效性研究，但很少用于有机污染物采样。本项目将制备一种特异性强、容量大、吸附速度快的分子印迹纳米粒子（MINP），利用其优异吸附性能，构建适合极性有机物高效提取的结合相，发展基于DGT的水体痕量抗生素原位采样方法。将选择几种应用广、环境检出率高的抗生素为对象，采用可逆加成–断裂链转移表面分子印迹技术在碳纳米材料表面制备印迹膜（即MINP），考察MINP对抗生素的吸附特性；构建MINP结合相及采样装置，研究结合相对抗生素的结合特性及pH值、离子强度、共存物质、提取时间等因素的影响，确定DGT装置参数和采样条件，建立水体中痕量抗生素原位采样方法，比较DGT原位采样与常规采样对不同水体典型抗生素采样分析结果的相关性。项目的实施将促进有机污染物DGT采样的基础理论和技术，为有机污染物的原位监测、生物有效性研究提供技术支撑。

本项目研制了基于分子印迹材料、金属有机框架—多孔碳材料的新型结合相，新结合相具有容量大、选择性好、稳定等优点，基于这些结合相，建立了地表水、城市废水、海水中抗生素的DGT原位测定方法，并进行实际现场应用。研究结果显示：基于DGT的被动采样分析结果与传统主动采样结果一致，从这些水体中均可以检测出抗生素，主要以喹诺酮和磺胺类抗生素为主，海水中抗生素浓度在0~50 ng/L，城市污水处理厂不能将抗生素类微污染物完全去除，抗生素浓度在0~1000 ng/L。发展的DGT原位测定方法用于土壤中四环素的解析行为研究，揭示了抗生素从土壤固相到土壤溶液的动态补给机制。发展了基于二氧化铈的DGT技术，用于地表水、海水及沉积物中无机砷、溶解性有机磷的原位测定。项目执行期间，发表论文9篇(SCI论文8篇，IF大于5.0的3篇)，申请发明专利3项(授权1项)，培养研究生5人(毕业3人)，参加学术会议14人次，口头报告7人次，提交会议摘要13篇。项目的实施促进了DGT基础理论，拓展了DGT的应用领域，为环境中抗生素、无机砷、溶解性有机磷的原位监测提供了新的技术手段。