Examining superoxide dynamics in irradiated natural waters
Examining superoxide dynamics in irradiated natural waters
复制标题
DOI：
10.1002/lno.12316
复制
发表时间：
2023-02
影响因子：
4.5
通讯作者：
K. Arlinghaus;A. Frossard;W. Miller
中科院分区：
文献类型：
--
作者：
K. Arlinghaus;A. Frossard;W. Miller
超氧化物（O2−）是一种活性氧物质（ROS），主要由光氧化的发色溶解有机物（CDOM）在阳光照射的天然沃茨中单电子转移到O2产生。在这里，我们研究环境和化学参数（pH值，离子强度，缓冲液和卤化物），可能会影响O2-光化学生产率和衰变途径在天然水。使用酶超氧化物歧化酶和H2 O2测量，我们提出的结果，从辐照淡水CDOM源表明，O2-还原衰变途径（P/PSOD）占主导地位，增加pH值和NaCl的添加和最大光产率（RO 2-）增加碳酸盐相比，硼酸盐缓冲液。辐照2 h后，观察到所有样品沿着的RO 2 −显著下降，氧化途径略有增加。这些结果意味着O2−衰变途径和生产率的变化，似乎在天然沃茨中有所不同，并作为辐照历史的函数。
Superoxide ( O2− ) is a reactive oxygen species (ROS) that is primarily produced by the one‐electron transfer of photooxidized chromophoric dissolved organic matter (CDOM) to O2 in sunlit natural waters. Here we examine the environmental and chemical parameters (pH, ionic strength, buffer, and halides) that may influence O2− photochemical production rates and decay pathways in natural water. Using the enzyme superoxide dismutase and H2O2 measurements, we present results from an irradiated freshwater CDOM source indicating that O2− reductive decay pathways (P/PSOD) dominate with increased pH and NaCl additions and maximal photoproduction rates ( RO2− ) increase with carbonate compared to borate buffer. Over 2 h of irradiation, a significant decline in RO2− was seen for all samples along with a minor increase in oxidative pathways. These results imply shifts in O2− decay pathways and production rates that seem to vary across natural waters and as a function of irradiation history.