Changes in freshwater organic matter fluorescence intensity with freezing/thawing and dehydration/rehydration
Changes in freshwater organic matter fluorescence intensity with freezing/thawing and dehydration/rehydration
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DOI：
10.1029/2008jg000915
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发表时间：
2009-12-16
影响因子：
3.7
通讯作者：
Ward, D.
中科院分区：
文献类型：
--
作者：
Hudson, N.;Baker, A.;Ward, D.
由于光降解和生物降解过程对碳循环的影响，在所有水生系统中对水生有机物不稳定性的影响进行了广泛的研究，其中大多数研究都是在溶解有机部分上进行的。很少有研究已经发表到冻结/解冻和脱水/复水的影响，虽然这些是在自然界中经常遇到的机制。在这项工作中，从英格兰中部的13个淡水进行了分析化学水质，总有机碳，和有机物荧光使用激发-发射矩阵（EEMs）。样品在脱水或冷冻条件下储存，未经过滤，然后再水化或解冻，并在5个循环内分析荧光。冻融和脱水/复水对总有机物荧光的影响通过EEM光谱上测量的四个共同峰的荧光强度的变化来评估。在一个和五个分析循环后，发现样品光谱以样品特异性方式响应;尽管荧光强度通常降低，但降低的幅度在荧光峰和样品之间是可变的。冷冻/解冻和脱水/复水提供了有用的信息，淡水有机物荧光的敏感性，这些环境过程。
The effects of photodegradation and biodegradation upon aquatic organic matter lability have been extensively researched in all aquatic systems because of the impact of these processes upon carbon cycling, with most studies undertaken on the dissolved organic fraction. Little research has been published into the effect of freezing/thawing and dehydration/rehydration although these are mechanisms which are often encountered in nature. In this work, 13 freshwaters from central England were analyzed for chemical water quality, total organic carbon, and organic matter fluorescence using excitation-emission-matrices (EEMs). Samples were stored unfiltered under dehydrated or frozen conditions, then rehydrated or thawed, and analyzed for fluorescence over five cycles. The effect of freezing/thawing and dehydration/rehydration upon total organic matter fluorescence was assessed through changes in fluorescence intensity of four common peaks measured on the EEM spectra. Sample spectra were found to respond in a sample specific manner after one and five cycles of analysis; although fluorescence intensity generally decreased, the magnitude of decrease was variable between fluorescence peaks and samples. Freezing/thawing and dehydration/rehydration provide useful information on the sensitivity of freshwater organic matter fluorescence to these environmental processes.