The effect of standard acid maceration on organic matter (OM) from ancient silicified sediments remains undocumented. Early silicification favours preservation of organic moieties against thermal alteration over time. In this study, we investigated the effects of acid maceration on the structure of OM isolated from the Lower Devonian Rhynie chert. The structure of OM was investigated by combining Rock-Eval pyrolysis and Raman spectroscopy. Besides a loss of thermolabile organic matter owing to solvent extraction, Rock-Eval pyrolysis showed that standard acid maceration also causes a loss of CH emissions at high pyrolysis temperature (>500 °C). The standard acid maceration procedure was also associated with the disappearance of the D4 and D5 Raman spectrum shoulders assigned to CH bonds in aliphatics and bitumens, respectively, entrapped in the macromolecular network. Taken together, Rock-Eval pyrolysis and Raman spectroscopy indicate that standard acid maceration can lead to the chemical degradation of syngenetic hydrocarbonaceous moieties of OM isolated from ancient silicified and thermally altered sediments. In sediments having experienced early silicification, which hampers bitumen migration and favours pyrobitumen formation, we suggest that novel in situ molecular analytical techniques are required to provide a thorough examination of the syngenetic molecular content independent of the soluble/insoluble operational definition.

标准的酸浸对古代硅化沉积物中的有机物（OM）的影响尚无记录。早期硅化有利于保存有机部分以防止随着时间的推移发生热变化。在这项研究中，我们调查了酸浸对分离自下泥盆世Rhynie cher石的OM结构的影响。通过结合岩石-Eval热解和拉曼光谱研究了OM的结构。除了由于溶剂萃取而导致的对热不稳定的有机物的损失外，Rock-Eval热解法还表明，标准的酸浸法在高温条件下（> 500°C）也会造成C H排放量的损失。标准的酸浸程序还与分配给C的D4和D5拉曼光谱谱肩的消失有关脂族和沥青中的H键分别包裹在大分子网络中。总之，Rock-Eval热解法和拉曼光谱法表明，标准的酸浸可以导致从古老的硅化和热蚀变沉积物中分离出的OM的同质烃类部分发生化学降解。在经历了早期硅化作用的沉积物中，这会阻碍沥青的迁移并促进焦磷酸酶的形成，我们建议需要使用新颖的原位分子分析技术来彻底检查同系物分子含量，而与可溶/不可溶操作定义无关。