Advancing our understanding of dissolved organic matter (DOM) chemistry in aquatic systems necessitates the integration of data streams from multiple analytical platforms. Some measurements require pretreatment with solid phase extraction (SPE), while others are performed directly on whole water samples. Evidence has suggested that SPE will be biased against select DOM fractions, leading to concerns over the ability to establish data linkages across platforms with variable needs for SPE pretreatment, such as those from optical measurements and those that provide high‐resolution molecular information. Here, we directly addressed this concern by assessing the impact of SPE on DOM optical properties through excitation–emission matrices with parallel factor analysis (PARAFAC) for 47 samples across a stream network within a single watershed reflective of variable DOM sources. PARAFAC data was further paired with molecular information obtained by Fourier transform ion cyclotron resonance mass spectrometry (FTICR‐MS). A comparison of PARAFAC models first revealed no systematic qualitative differences in major components between whole water DOM and DOM isolated by SPE (SPE‐DOM); however, quantitative biases against select components were observed. Further linkages with FTICR‐MS data revealed that the molecular fingerprint associated with each PARAFAC component was consistent between the whole water DOM and SPE‐DOM. Our results suggest that bulk scale linkages across these analytical platforms could be inferred irrespective of the observed quantitative biases resulting from SPE for samples within this example watershed. This work represents a key step toward the systematic evaluation of linkages between optical and high‐resolution mass spectrometry datasets in freshwater lotic environments.

中文翻译：

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研究固相萃取对溶解有机物光学特征的影响以及与淡水流网络中高分辨率质谱数据的配对

为了加深我们对水生系统中溶解有机物 (DOM) 化学的理解，需要整合来自多个分析平台的数据流。有些测量需要使用固相萃取 (SPE) 进行预处理，而其他测量则直接对整个水样进行。有证据表明，SPE 对选定的 DOM 组分存在偏见，导致人们担心跨平台建立数据链接的能力，这些平台对 SPE 预处理的需求存在差异，例如来自光学测量的数据和提供高分辨率分子信息的数据。在这里，我们通过激发发射矩阵与并行因子分析 (PARAFAC) 评估 SPE 对 DOM 光学性质的影响，直接解决了这个问题，该矩阵针对反映可变 DOM 源的单个分水岭内的流网络中的 47 个样本。PARAFAC 数据进一步与傅里叶变换离子回旋共振质谱 (FTICR-MS) 获得的分子信息配对。PARAFAC 模型的比较首先揭示了全水 DOM 和通过 SPE 分离的 DOM (SPE-DOM) 之间的主要成分没有系统的定性差异；然而，观察到针对选定成分的定量偏差。与 FTICR-MS 数据的进一步联系表明，与每个 PARAFAC 组分相关的分子指纹在全水 DOM 和 SPE-DOM 之间是一致的。我们的结果表明，无论本示例分水岭内的样品的 SPE 所观察到的定量偏差如何，都可以推断出这些分析平台之间的大规模联系。这项工作代表了系统评估淡水环境中光学和高分辨率质谱数据集之间联系的关键一步。