Abstract Carbohydrates serve as structural materials, energy storage compounds, and energy carriers in organisms and provide insights into the dominant sources and the degradation state of organic matter (OM). Several studies have analyzed dissolved and/or particulate carbohydrates in the environment, often with the aim of studying particular carbohydrate groups of interest. These studies have often employed different acids and hydrolytic conditions, making comparisons across studies a challenge. Here, we introduce a sequential acid hydrolysis protocol for the comprehensive extraction, quantification and compositional investigation of carbohydrates in sediment samples. This protocol has four acid hydrolysis steps that sequentially increase in extraction strength, where each subsequent hydrolysis step is performed on the unextracted remains previously hydrolyzed. The four hydrolysis steps consist of 1 M HCl for 2 h at (1) room temperature, (2) 50 °C, and (3) 105 °C, followed by incubation for 8 h using (4) 6 M HCl and 105 °C. Based on tests using diverse carbohydrate standard compounds, the protocol recovers most di- and oligosaccharides and soluble polysaccharides during the initial hydrolysis steps, whereas the recovery of most insoluble polysaccharides is highest during the final extraction step. Applying this protocol to different sediment types shows that recoveries of neutral sugars, amino sugars and sugar alcohols are on average ~60% higher than with a reference one-step extraction method using only hydrolysis with hot 6 M HCl. This sequential extraction protocol thus provides an important new tool for the quantitative and compositional analysis of carbohydrates in aquatic sediments.

中文翻译：

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通过顺序水解提高沉积碳水化合物的提取效率

摘要 碳水化合物作为生物体的结构材料、储能化合物和能量载体，为了解有机物 (OM) 的主要来源和降解状态提供了见解。一些研究分析了环境中溶解的和/或颗粒状碳水化合物，通常目的是研究感兴趣的特定碳水化合物组。这些研究通常采用不同的酸和水解条件，这使得跨研究的比较成为一项挑战。在这里，我们介绍了一种连续酸水解方案，用于对沉积物样品中的碳水化合物进行全面的提取、定量和成分调查。该协议有四个酸水解步骤，依次增加提取强度，其中每个后续的水解步骤都是对先前水解的未提取残留物进行的。四个水解步骤包括在 (1) 室温、(2) 50 °C 和 (3) 105 °C 下 1 M HCl 2 小时，然后使用 (4) 6 M HCl 和 105 °C 孵育 8 小时C。基于使用不同碳水化合物标准化合物的测试，该协议在最初的水解步骤中回收了大多数二糖和寡糖以及可溶性多糖，而在最后的提取步骤中，大多数不溶性多糖的回收率最高。将此协议应用于不同的沉积物类型表明，中性糖、氨基糖和糖醇的回收率平均比仅使用热 6 M HCl 水解的参考一步提取方法高约 60%。