Sample acidification significantly alters stable isotope ratios of sulfur in aquatic plants and animals
Sample acidification significantly alters stable isotope ratios of sulfur in aquatic plants and animals
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DOI：
10.3354/meps10560
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发表时间：
2013-01-01
影响因子：
2.5
通讯作者：
Schlacher, Thomas A.
中科院分区：
文献类型：
--
作者：
Connolly, Rod M.;Schlacher, Thomas A.
在现代和历史食物网的研究中，硫稳定同位素越来越多地被用作材料加工的示踪剂。用于同位素分析的动植物材料的准备通常包括去除消费者通常不能吸收的无机材料的步骤。虽然已知酸化有助于某些元素(碳)的这一点，但它可能对其他元素(氮)产生不必要的影响。通过比较酸化前后海草、附生藻类和动物消费者(甲壳类3种类型：双足类、桡足类和等足类)的硫同位素比值，研究了酸化对硫同位素的影响。酸处理导致组织中元素硫的显著损失和样品硫同位素比值的变化。重硫同位素的人为枯竭使硫同位素比值平均下降2.6%，个别样品下降高达7.0%。在硫同位素分析之前对样品进行酸化会导致无效的比率，因此不应使用。
Sulfur stable isotopes are increasingly being used as tracers of material processing in studies of both modern and historical food webs. Preparation of plant and animal material for isotope analysis routinely includes steps that remove inorganic material not normally assimilated by consumers. Whereas acidification of samples is known to assist with this for some elements (carbon), it can produce unwanted effects for others (nitrogen). Here we tested the effects of acidification on sulfur isotopes by comparing isotope ratios of paired acidified and non-acidified samples of seagrass, epiphytic algae growing on seagrass and animal consumers (3 types of crustaceans: amphipods, copepods and isopods). Acid treatment resulted in significant losses of elemental sulfur from the tissues and changes in sulfur isotope ratios of samples. The artificial depletion of the heavy sulfur isotope decreased sulfur isotope ratios by 2.6% on average, and by as much as 7.0% in individual samples. Acidification of samples prior to sulfur isotope analysis results in invalid ratios and should not be used.