Auto-fluorescence is a significant challenge for Raman spectroscopic analyses. Since fluorescence is a much stronger phenomenon than Raman scattering, even trace fluorescent impurities can overwhelm the Raman signal. Strategies to minimize fluorescence interference in Raman measurements include either an instrumental-based approach or treatment of the sample itself to minimize fluorescence. Efforts focused on sample-based treatments to reduce fluorescence interferences have generally focused on sample purification and photobleaching methodologies. In this work, we present a sample treatment approach based upon chemical bleaching to remove fluorescence from Raman measurements of aqueous solutions of sulfonated polystyrene (SPS). Synthetic batches of SPS are characterized by a wide variation in fluorescence from minimum to a catastrophic level, which greatly limits the use of Raman spectroscopy. We systematically investigate the efficacy of various sample-based treatments of the SPS samples. An important acceptance criterion is that the procedure effectively and reliably removes fluorescence without damaging the SPS component. The chemical bleaching, which involves the addition of hydrogen peroxide and incubation at 60 ℃, is found to be highly effective. The parameters affecting the bleaching efficacy are studied, including temperature, hydrogen peroxide dosage, and bleaching time. Classification models are then developed based on the drastically diverse fluorescence background levels in Raman spectra of SPS to help optimize bleaching time for each specific sample. This work serves as an example of using chemical bleaching to remove fluorescence, which is inexpensive and readily available. It can facilitate a broader use of Raman spectroscopy as a quantitative qualitative control method in industrial settings.

中文翻译：

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EXPRESS：化学漂白以最大限度地减少磺化聚苯乙烯 (SPS) 溶液拉曼光谱测量中的荧光干扰

自发荧光是拉曼光谱分析的重大挑战。由于荧光是比拉曼散射强得多的现象，因此即使是痕量荧光杂质也会压倒拉曼信号。最大限度减少拉曼测量中荧光干扰的策略包括基于仪器的方法或样品本身的处理以最大限度地减少荧光。集中在基于样本的处理以减少荧光干扰的努力通常集中在样本纯化和光漂白方法上。在这项工作中，我们提出了一种基于化学漂白的样品处理方法，以从磺化聚苯乙烯 (SPS) 水溶液的拉曼测量中去除荧光。合成批次的 SPS 的特点是荧光从最小到灾难性水平变化很大，这极大地限制了拉曼光谱的使用。我们系统地研究了 SPS 样品的各种基于样品的处理的功效。一个重要的验收标准是该程序有效且可靠地去除荧光而不损坏 SPS 组件。化学漂白，包括添加过氧化氢和在 60 ℃下孵育，被发现是非常有效的。研究了影响漂白效果的参数，包括温度、过氧化氢剂量和漂白时间。然后根据 SPS 拉曼光谱中极其不同的荧光背景水平开发分类模型，以帮助优化每个特定样品的漂白时间。这项工作是使用化学漂白去除荧光的一个例子，这是便宜且容易获得的。它可以促进拉曼光谱在工业环境中作为定量定性控制方法的更广泛使用。