Fluorescence peak integration ratio IC: IT as a new potential indicator tracing the compositional changes in chromophoric dissolved organic matter
Fluorescence peak integration ratio IC: IT as a new potential indicator tracing the compositional changes in chromophoric dissolved organic matter
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荧光峰积分比 IC：IT 作为追踪发色溶解有机物成分变化的新潜在指标
DOI：
10.1016/j.scitotenv.2016.08.196
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发表时间：
2017
影响因子：
9.8
通讯作者：
Zhu Guangwei
中科院分区：
文献类型：
--
作者：
Zhou Yongqiang;Shi Kun;Zhang Yunlin;Jeppesen Erik;Liu Xiaohan;Zhou Qichao;Wu Huawu;Tang Xiangming;Zhu Guangwei
本研究表明，峰 C 与峰 T 的荧光积分比 (IC:IT) 可用作追踪发色溶解有机物 (CDOM) 组成动态的指标。 CDOM 吸收光谱和荧光光谱以及稳定同位素 δ13C 在 17 个中国内陆水域中按季节进行测定，并在实验室进行了一系列混合和光降解实验。通过平行因子分析得出，IC:IT 与陆地腐殖酸类 C1 与色氨酸类 C4 的比率 (C1:C4) 之间存在很强的正线性相关性。 IC:IT 和 C1:C4 之间的线性拟合 (r2= 0.80) 显着高于 C1:C4 和其他测试指标之间的线性拟合，包括 CDOM 在 250 nm 与 365 nm 处的吸收比，即a(250):a(365) (r2= 0.09)、光谱斜率 (S275–295) (r2= 0.26)、光谱斜率 (SR) (r2= 0.31)、腐殖化指数 (HIX) (r2= 0.47)、近期本地生物贡献指数 (BIX) (r2= 0.27) 和荧光指数 (FI370) (r2= 0.07).IC:IT 表现出比其余六个指数更大的变异性，并且与现场活动期间观察到的 a(250):a(365)、S275–295、SR、FI370 和 BIX 相比，与稳定同位素 δ13C 的相关性更密切。证实了我们的现场观察，IC:IT 与其余六个指数之间记录了显着相关性，并且在我们的废水添加实验中，IC:IT 也表现出比其他六个指数显着更大的变异性。与HIX相比，富营养化水添加和光漂白显着降低了IC:IT，但对a(250):a(365)、S275–297、SR、FI370和BIX没有明显影响，进一步表明IC:IT是CDOM组成动态的最有效指标。
The present study demonstrates that the ratio of fluorescence integration of peak C to peak T (IC:IT) can be used as an indicator tracing the compositional dynamics of chromophoric dissolved organic matter (CDOM). CDOM absorption and fluorescence spectroscopy and stable isotope δ13C were determined on a seasonal basis in seventeen Chinese inland waters as well as in a series of mixing and photodegradation experiments in the lab. A strong positive linear correlation was recorded betweenIC:ITand the ratio of terrestrial humic-like C1 to tryptophan-like C4 (C1:C4) derived by parallel factor analysis. Ther2for the linear fitting betweenIC:ITand C1:C4 (r2= 0.80) was notably higher than between C1:C4 and other indices tested, including the ratio of CDOM absorption at 250 nm to 365 nm,i.e. a(250):a(365) (r2= 0.09), spectral slope (S275–295) (r2= 0.26), spectral slope ratio (SR) (r2= 0.31), the humification index (HIX) (r2= 0.47), the recent autochthonous biological contribution index (BIX) (r2= 0.27), and a fluorescence index (FI370) (r2= 0.07).IC:ITexhibited larger variability than the remaining six indices and a closer correlation with stable isotope δ13C than that observed fora(250):a(365),S275–295,SR,FI370, and BIX during field campaigns. Confirming our field observations, significant correlations were recorded betweenIC:ITand the remaining six indices, andIC:ITalso demonstrated notably larger variability than the six other indices during our wastewater addition experiment. Compared with HIX, eutrophic water addition and photobleaching substantially decreasedIC:ITbut had no pronounced effect ona(250):a(365),S275–297,SR,FI370, and BIX, further suggesting thatIC:ITis the most efficient indicator of the CDOM compositional dynamics.