Centro de Investigación Aplicada en Ambiente Y Salud (CIAAS), Avenida Sierra Leona No. 550, CP 78210, Colonia Lomas Segunda Sección, San Luis Potosí, SLP, México.
Centro de Investigación Y Estudios de Posgrado, Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, San Luis Potosí, 78260, México.
Environ Sci Pollut Res Int. 2022 Jun;29(30):45885-45902. doi: 10.1007/s11356-022-19130-0. Epub 2022 Feb 12.
In this study, a series of molecularly imprinted polymers (MIPs) have been synthesized using separately diclofenac, naproxen, and ibuprofen as templates with three different polymerization approaches. Two functional monomers, methacrylic acid (MAA) and 2-vinylpyridine (2-VP), were tested and ethylene glycol dimethacrylate (EGDMA) was used as crosslinker; also, template-free polymers (NIPs) were synthesized. It was found that the MIP with the highest retention percentage for diclofenac was the one prepared by the emulsion approach and with MAA (98.3%); for naproxen, the one prepared by the bulk polymerization with MAA (99%); and for ibuprofen, the one synthesized by bulk with 2-VP (97.7%). These three MIPs were characterized by scanning electron microscopy, thermogravimetric test, Fourier transform infrared, specific area measurements, and surface charge. It was found that the emulsion method allowed particle size control, while the bulk method gave heterogeneous particles. The three evaluated MIPs exhibited thermal stability up to 300 °C, and it was observed that 2-VP confers greater stability to the material. From the BET analysis, it was demonstrated that the MIPs and NIPs evaluated are mesoporous materials with a pore size between 10 and 20 nm. In addition, the monomer influenced the surface charge of the material, since the MAA conferred an acidic point of zero charge (PZC), while the 2-VP conferred a PZC of basic character. Through adsorption isotherms, it was determined that there is a higher adsorption capacity of the MIPs at acidic pH following a pseudo-second-order kinetic model. Finally, the MIPs were used to determine the non-steroidal anti-inflammatory drugs (NSAIDs) understudy in San Luis Potosí, México, wastewater, finding concentrations of 0.642, 0.985, and 0.403 mg L for DCF, NPX, and IBP, respectively.
在这项研究中，使用三种不同的聚合方法，分别以双氯芬酸、萘普生和布洛芬为模板合成了一系列分子印迹聚合物（MIPs）。测试了两种功能单体，即甲基丙烯酸（MAA）和 2-乙烯基吡啶（2-VP），并使用乙二醇二甲基丙烯酸酯（EGDMA）作为交联剂；同时，还合成了无模板聚合物（NIPs）。结果发现，对双氯芬酸保留率最高的 MIP 是通过乳液法制备的，使用的单体是 MAA（98.3%）；对于萘普生，通过使用 MAA 的本体聚合制备的 MIP（99%）；对于布洛芬，通过使用 2-VP 的本体聚合合成的 MIP（97.7%）。通过扫描电子显微镜、热重测试、傅里叶变换红外光谱、比表面积测量和表面电荷对这三种 MIP 进行了表征。结果发现，乳液法可以控制粒径，而本体法则会产生不均匀的颗粒。三种评价的 MIP 表现出高达 300°C 的热稳定性，并且观察到 2-VP 赋予材料更大的稳定性。从 BET 分析中可以看出，评价的 MIPs 和 NIPs 是介孔材料，孔径在 10 到 20nm 之间。此外，单体影响材料的表面电荷，因为 MAA 赋予了材料的零电荷点（PZC）呈酸性，而 2-VP 赋予了 PZC 呈碱性。通过吸附等温线，确定在酸性 pH 下，MIPs 具有更高的吸附能力，遵循准二级动力学模型。最后，将 MIPs 用于测定墨西哥圣路易斯波托西的废水中研究的非甾体抗炎药（NSAIDs），发现 DCF、NPX 和 IBP 的浓度分别为 0.642、0.985 和 0.403mg/L。
