EUDIM, Escuela Universitaria de Ingeniería Mecánica, Universidad de Tarapacá, Av. General Velásquez, 1775, Arica, Chile.
CIESOL, Joint Centre University of Almería-CIEMAT, Almería, Spain.
Water Res. 2018 Jan 1;128:61-70. doi: 10.1016/j.watres.2017.10.047. Epub 2017 Oct 23.
This paper deals with the photochemical fate of two representative carbapenem antibiotics, namely imipenem and meropenem, in aqueous solutions under solar radiation. The analytical method employed for the determination of the target compounds in various aqueous matrices, such as ultrapure water, municipal wastewater treatment plant effluents, and river water, at environmentally relevant concentrations, was liquid chromatography coupled with hybrid triple quadrupole-linear ion trap-mass spectrometry. The absorption spectra of both compounds were measured in aqueous solutions at pH values from 6 to 8, and both compounds showed a rather strong absorption band centered at about 300 nm, while their molar absorption coefficient was in the order from 9 × 10-10 L mol cm. The kinetics of the photochemical degradation of the target compounds was studied in aqueous solutions under natural solar radiation in a solar reactor with compound parabolic collectors. It was found that the photochemical degradation of both compounds at environmentally relevant concentrations follows first order kinetics and the quantum yield was in the order of 10 mol einsten. Several parameters were studied, such as solution pH, the presence of nitrate ions and humic acids, and the effect of water matrix. In all cases, it was found that the presence of various organic and inorganic constituents in the aqueous matrices do not contribute significantly, either positively or negatively, to the photochemical degradation of both compounds under natural solar radiation. In a final set of photolysis experiments, the effect of the level of irradiance was studied under simulated solar radiation and it was found that the quantum yield for the direct photodegradation of both compounds remained practically constant by changing the incident solar irradiance from 28 to 50 W m.
本文研究了两种代表性碳青霉烯类抗生素——亚胺培南和美罗培南在水溶液中，于太阳辐射下的光化学命运。在环境相关浓度下，采用液相色谱与混合三重四极杆-线性离子阱-质谱联用的分析方法，对超纯水、城市污水处理厂出水和河水等各种水基质中的目标化合物进行了测定。测量了两种化合物在 pH 值为 6 到 8 的水溶液中的吸收光谱，两种化合物在约 300nm 处均显示出相当强的吸收带，而它们的摩尔吸光系数则在 9×10-10 L mol cm 左右。在带有复合抛物面集热器的太阳反应器中，于自然太阳辐射下，研究了目标化合物在水溶液中的光化学降解动力学。研究发现，在环境相关浓度下，两种化合物的光化学降解均遵循一级动力学，量子产率在 10 mol einsten 左右。研究了溶液 pH 值、硝酸盐离子和腐殖酸的存在以及水基质的影响等多个参数。在所有情况下，均发现水基质中各种有机和无机成分的存在，无论正面还是负面，均不会对两种化合物在自然太阳辐射下的光化学降解产生显著影响。在一系列最终的光解实验中，在模拟太阳辐射下研究了辐照度水平的影响，结果发现，通过将入射太阳辐照度从 28 到 50 W m 变化，两种化合物的直接光降解量子产率实际上保持不变。
