Photochemically Induced Changes of Dissolved Organic Matter in a Humic-Rich and Forested Stream
Photochemically Induced Changes of Dissolved Organic Matter in a Humic-Rich and Forested Stream
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富含腐殖质和森林的溪流中溶解有机物的光化学诱导变化
DOI：
10.3390/w12020331
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发表时间：
2020
期刊：
影响因子：
3.4
通讯作者：
W. von Tümpling
中科院分区：
文献类型：
--
作者：
Christin Wilske;P. Herzsprung;O. Lechtenfeld;N. Kamjunke;W. von Tümpling
光化学处理是转化陆地溶解有机质（DOM）的重要途径，但超高分辨率质谱法的研究很少。我们进行了一项辐照实验，实验用水来自阴凉的森林溪流，流入一个点燃的水库。细菌活性仅解释了细菌和光降解联合方法中溶解有机碳（DOC）下降的1%。在6天内，光降解使DOC浓度降低30%，比紫外线（UV）吸收率降低40%-50%，荧光强度降低80%。腐殖化指数（HIX）降低，荧光指数（FI）不变。激发-发射基质平行因子分析（PARAFAC）鉴定出的两种腐殖质样成分随荧光DOM的减少而减少。利用Spearman秩相关和线性回归分析了傅里叶变换-离子回旋共振质谱（FT-ICR MS）元素公式组分相对峰强度随累积辐射的变化。FT-ICR MS强度变化表明，高芳香族物质被光化学转化为更小的非荧光分子或被CO2释放降解。本研究揭示了地表DOM在水库饮用水制备前的分子变化。
Photochemical processing is an important way to transform terrestrial dissolved organic matter (DOM) but was rarely investigated by ultra-high resolution mass spectrometry. We performed an irradiation experiment with water from a shaded forest stream flowing into a lit reservoir. Bacterial activity explained only 1% of dissolved organic carbon (DOC) decline in a combined bacterial and photodegradation approach. Photodegradation decreased the DOC concentration by 30%, the specific ultraviolet (UV) absorption by 40%–50%, and fluorescence intensity by 80% during six days. The humification index (HIX) decreased whereas the fluorescence index (FI) did not change. Two humic-like components identified by parallel factor analysis (PARAFAC) of excitation–emission matrices followed the decrease of fluorescent DOM. Changes of relative peak intensities of Fourier transform-ion cyclotron resonance mass spectroscopy (FT-ICR MS) elemental formula components as a function of cumulated radiation were evaluated both by Spearman’s rank correlation and linear regression. The FT-ICR MS intensity changes indicate that high aromatic material was photochemically converted into smaller non-fluorescent molecules or degraded by the release of CO2. This study shows the molecular change of terrestrial DOM before the preparation of drinking water from reservoirs.
影响因子：
11.4
作者：
Gomez-Saez, Gonzalo V.;Pohlabeln, Anika M.;Dittmar, Thorsten
通讯作者：
Dittmar, Thorsten
影响因子：
11.4
作者：
Maizel AC;Remucal CK
通讯作者：
Remucal CK
影响因子：
4.9
作者：
Flerus, R.;Lechtenfeld, O. J.;Kattner, G.
通讯作者：
Kattner, G.