Jiménez-Holgado Cristina, Sakkas Vasilios, Richard Claire
Laboratory of Analytical Chemistry, Department of Chemistry, School of Sciences, University of Ioannina, 45110 Ioannina, Greece.
Institute of Chemistry of Clermont-Ferrand, Université Clermont Auvergne, CNRS, SIGMA-Clermont, ICCF, F-63000 Clermont-Ferrand, France.
Molecules. 2021 Apr 23;26(9):2466. doi: 10.3390/molecules26092466.
Psychoactive drugs are classified as contaminants of emerging concern but there is limited information on their fate in surface waters. Here, we studied the photodegradation of three psychoactive drugs (sertraline, clozapine, and citalopram) in the presence of organic matter (WEOM) extracted under mild conditions from sediment of Lake Pamvotis, Greece. Spectral characterization of WEOM confirmed its humic-like nature. Preliminary experiments using chemical probes showed that WEOM was able to produce oxidant triplet excited state (WEOM*), singlet oxygen (O), and hydroxyl radicals under irradiation with simulated solar light. Then, WEOM at 5 mgC L was irradiated in the presence of the three drugs. It enhanced their phototransformation by a factor of 2, 4.2, and 16 for sertraline, clozapine, and citalopram, respectively. The drastic inhibiting effect of 2-propanol (5 × 10 M) on the reactions demonstrated that hydroxyl radical was the key intermediate responsible for drugs photodegradation. A series of photoproducts were identified by ultra-high performance liquid chromatography (UHPLC) coupled to high resolution mass spectrometry (HR-MS). The photodegradation of the three drugs proceeded through several pathways, in particular oxidations of the rings with or without O atom inclusion, N elimination, and substitution of the halogen by OH. The formation of halogenated aromatics was observed for sertraline. To conclude, sedimental natural organic matter can significantly phototransform the studied antidepressant drugs and these reactions need to be more investigated. Finally, ecotoxicity was estimated for the three target analytes and their photoproducts, using the Ecological Structure Activity Relationships (ECOSAR) computer program.
精神活性药物被归类为新出现的关注污染物，但关于它们在地表水中的归宿信息有限。在此，我们研究了三种精神活性药物（舍曲林、氯氮平和西酞普兰）在从希腊帕姆沃蒂斯湖沉积物中温和条件下提取的有机物（WEOM）存在下的光降解情况。WEOM的光谱表征证实了其类腐殖质性质。使用化学探针的初步实验表明，WEOM在模拟太阳光照射下能够产生氧化三重激发态（WEOM*）、单线态氧（O）和羟基自由基。然后，在三种药物存在下对5 mgC/L的WEOM进行照射。对于舍曲林、氯氮平和西酞普兰，它分别将它们的光转化提高了2倍、4.2倍和16倍。2-丙醇（5×10⁻³ M）对反应的显著抑制作用表明羟基自由基是负责药物光降解的关键中间体。通过超高效液相色谱（UHPLC）与高分辨率质谱（HR-MS）联用鉴定了一系列光产物。这三种药物的光降解通过多种途径进行，特别是有或没有氧原子包含的环氧化、氮消除以及卤素被羟基取代。在舍曲林的情况下观察到了卤代芳烃的形成。总之，沉积的天然有机物可以显著光转化所研究的抗抑郁药物，这些反应需要进一步研究。最后，使用生态结构活性关系（ECOSAR）计算机程序对三种目标分析物及其光产物的生态毒性进行了评估。
