Development of an in Situ NMR Photoreactor To Study Environmental Photochemistry
Development of an in Situ NMR Photoreactor To Study Environmental Photochemistry
复制标题
DOI：
10.1021/acs.est.6b00361
复制
发表时间：
2016-06-07
影响因子：
11.4
通讯作者：
Simpson, Andre J.
中科院分区：
文献类型：
--
作者：
Bliumkin, Liora;Majumdar, Rudraksha Dutta;Simpson, Andre J.
光化学是一个关键的环境过程，直接关系到环境中污染物的命运、来源和毒性。本研究探索了将光源与核磁共振（NMR）光谱学相结合的两种方法：在磁铁外部使用“阳光模拟器”照射样品，而在磁铁内部直接照射样品。为了评估其适用性，将原位核磁共振光反应器应用于一系列环境系统：大气污染物（对硝基酚）、原油提取物和地下水。该研究成功地说明了环境相关的水光化学过程可以使用核磁共振波谱进行现场和实时监测。一系列的中间体和降解产物被确定并与文献相匹配。通过动力学曲线初步测定了半衰期。太阳模拟器被证明是最适合的模型来探索环境光解过程的原位。其他具有更强紫外线输出的光源有潜力评估紫外线作为废水处理厂或石油泄漏等领域的补救替代方案。最后，利用低温探针分析地下水中天然丰度微量化学物质的光解命运的能力，证明了核磁共振波谱作为一种强大的补充技术在一般环境应用中的可行性。
Photochemistry is a key environmental process directly linked to the fate, source, and toxicity of pollutants in the environment. This study explores two approaches for integrating light sources with nuclear magnetic resonance (NMR) spectroscopy: sample irradiation using a "sunlight simulator" outside the magnet versus direct irradiation of the sample inside the magnet. To assess their applicability, the in situ NMR photoreactors were applied to a series of environmental systems: an atmospheric pollutant (p-nitrophenol), crude oil extracts, and groundwater. The study successfully illustrates that environmentally relevant aqueous photochemical processes can be monitored in situ and in real time using NMR spectroscopy. A range of intermediates and degradation products were identified and matched to the literature. Preliminary measurements of half-lives were also obtained from kinetic curves. The sunlight simulator was shown to be the most suitable model to explore environmental photolytic processes in situ. Other light sources with more intense UV output hold potential for evaluating UV as a remediation alternative in areas such as wastewater treatment plants or oil spills. Finally, the ability to analyze the photolytic fate of trace chemicals at natural abundance in groundwater, using a cryogenic probe, demonstrates the viability of NMR spectroscopy as a powerful and complementary technique for environmental applications in general.