Nedić Vasiljević Bojana, Milojević-Rakić Maja, Ranković Maja, Jevremović Anka, Ignjatović Ljubiša, Gavrilov Nemanja, Uskoković-Marković Snežana, Janošević Ležaić Aleksandra, Wang Hong, Bajuk-Bogdanović Danica
Faculty of Physical Chemistry, University of Belgrade, Studentski Trg 12-16, 11158 Belgrade, Serbia.
Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia.
Molecules. 2025 Aug 4;30(15):3267. doi: 10.3390/molecules30153267.
The competitive retention of pollutants in water tables determines their environmental fate and guides routes for their removal. To distinguish the fine differences in competitive binding at zeolite adsorption centers, a group of neonicotinoid pesticides is compared, relying on theoretical (energy of adsorption, orientation, charge distribution) and experimental (spectroscopic and thermogravimetric) analyses for quick, inexpensive, and reliable screening. The MOPAC/QuantumEspresso platform was used for theoretical calculation, indicating close adsorption energy values for acetamiprid and imidacloprid (-2.2 eV), with thiamethoxam having a lower binding energy of -1.7 eV. FTIR analysis confirmed hydrogen bonding, among different dipole-dipole interactions, as the dominant adsorption mechanism. Due to their comparable binding energies, when the mixture of all three pesticides is examined, comparative adsorption capacities are evident at low concentrations, owing to the excellent adsorption performance of the FAU zeotype. At higher concentrations, competition for adsorption centers occurs, with the expected thiamethoxam binding being diminished due to the lower bonding energy. The catalytic impact of zeolite on the thermal degradation of pesticides is evidenced through TG analysis, confirming the adsorption capacities found by UV/VIS and HPLC/UV measurements. Detailed analysis of spectroscopic results in conjunction with theoretical calculation, thermal profiles, and UV detection offers a comprehensive understanding of neonicotinoids' adsorption and can help with the design of future adsorbents.
地下水中污染物的竞争性截留决定了它们的环境归宿，并为其去除途径提供了指导。为了区分沸石吸附中心竞争性结合的细微差异，我们比较了一组新烟碱类农药，依靠理论分析（吸附能、取向、电荷分布）和实验分析（光谱和热重）进行快速、廉价且可靠的筛选。使用MOPAC/QuantumEspresso平台进行理论计算，结果表明啶虫脒和吡虫啉的吸附能值相近（-2.2 eV），而噻虫嗪的结合能较低，为-1.7 eV。傅里叶变换红外光谱（FTIR）分析证实，在不同的偶极-偶极相互作用中，氢键是主要的吸附机制。由于它们的结合能相近，当检测这三种农药的混合物时，在低浓度下，由于FAU型沸石出色的吸附性能，其比较吸附容量很明显。在较高浓度下，会发生对吸附中心的竞争，由于结合能较低，噻虫嗪预期的结合作用会减弱。通过热重分析（TG）证明了沸石对农药热降解的催化作用，证实了紫外可见光谱（UV/VIS）和高效液相色谱/紫外检测（HPLC/UV）所测得的吸附容量。结合理论计算、热分析曲线和紫外检测对光谱结果进行详细分析，有助于全面了解新烟碱类农药的吸附情况，并有助于未来吸附剂的设计。
