Isotopic composition of polyhalomethanes from marine macrophytes - systematic effects of the halogen substituents on isotopic composition
Isotopic composition of polyhalomethanes from marine macrophytes - systematic effects of the halogen substituents on isotopic composition
复制标题
海洋大型植物多卤甲烷的同位素组成 - 卤素取代基对同位素组成的系统影响
DOI：
10.1071/en14210
复制
发表时间：
2015
影响因子：
4.3
通讯作者：
W. Michaelis
中科院分区：
文献类型：
--
作者：
E. Bahlmann;C. Stolle;I. Weinberg;R. Seifert;D. Schulz;W. Michaelis
一旦释放到大气中，卤代烃就参与了关键的化学反应。卤代烃的稳定碳同位素测量可以提供有关其来源和在大气中的命运的宝贵信息。本文报道了褐藻释放的13种多卤甲烷的δ13C值，为今后的研究推测其来源和去向提供了依据。卤代烃是反应性卤素进入大气的重要载体，后者参与了几个关键的化学过程。提高对卤代烃生产-破坏平衡的生物地球化学控制的了解，对于解决未来卤代烃进入大气的通量可能发生的变化至关重要。卤代烃的碳稳定同位素比率可以提供有关其来源和命运的宝贵额外信息，而这些信息不能仅从混合比率中获得。测定了3种褐藻（海带、褐藻、褐藻）和1种海草（褐藻）中13种多卤甲烷的δ13C值。δ13C值是在光照、水位（模拟潮汐事件）和过氧化氢（H2O2）添加等不同环境条件下的实验室培养中测定的。多卤甲烷的δ13C值从CHCl3的-42.2‰（±3.5s.d.）到ch2br的6.9‰（±4.5）不等，表明卤素取代基的系统效应可以用线性自由能关系来描述。我们进一步观察到聚卤甲烷δ13C的富集与聚卤甲烷产率的下降，这是由于卤化酮的竞争形成。虽然多卤甲烷的同位素组成是可变的，但它可以为区分海洋多卤甲烷来源提供有用的额外信息。
Environmental context Once released to the atmosphere, halocarbons are involved in key chemical reactions. Stable carbon isotope measurements of halocarbons can provide valuable information on their sources and fate in the atmosphere. Here, we report δ13C values of 13 polyhalomethanes released from brown algae, which may provide a basis for inferring their sources and fate in future studies. Abstract Halocarbons are important vectors of reactive halogens to the atmosphere, where the latter participate in several key chemical processes. An improved understanding of the biogeochemical controls of the production–destruction equilibrium on halocarbons is of vital importance to address potential future changes in their fluxes to the atmosphere. Carbon stable isotope ratios of halocarbons could provide valuable additional information on their sources and fate that cannot be derived from mixing ratios alone. We determined the δ13C values of 13 polyhalomethanes from three brown algae species (Laminaria digitata, Fucus vesiculosus, Fucus serratus) and one seagrass species (Zostera noltii). The δ13C values were determined in laboratory incubations under variable environmental conditions of light, water levels (to simulate tidal events) and addition of hydrogen peroxide (H2O2). The δ13C values of the polyhalomethanes ranged from –42.2 ‰ (±3.5s.d.) for CHCl3 to 6.9 ‰ (±4.5) for CHI2Br and showed a systematic effect of the halogen substituents that could empirically be described in terms of linear free energy relationships. We further observed an enrichment in the δ13C of the polyhalomethanes with decreasing polyhalomethane yield that is attributed to the competing formation of halogenated ketones. Though variable, the isotopic composition of polyhalomethanes may provide useful additional information to discriminate between marine polyhalomethane sources.
OP3期间海洋大陆热带边界层的三溴甲烷
影响因子：
6.3
作者：
Pyle J
通讯作者：
Pyle J