A reproducible method for the extraction, identification and quantification of the Arctic sea ice proxy IP25 from marine sediments
A reproducible method for the extraction, identification and quantification of the Arctic sea ice proxy IP25 from marine sediments
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DOI：
10.1039/c2ay05728j
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发表时间：
2012-03-01
影响因子：
3.1
通讯作者：
Ingle, Rebecca
中科院分区：
文献类型：
--
作者：
Belt, Simon T.;Brown, Thomas A.;Ingle, Rebecca
IP25是一种高度分枝的类异戊二烯类脂生物标志物，由一些北极海冰硅藻在春季产生。海洋沉积物中IP25的存在以前曾被用作过去春季北极海冰发生情况的替代指标。本文首次提出了从海洋沉积物中提取、鉴定和定量测定IP25的可靠分析方法。该协议代表了一种标准操作程序(SOP)，将来应该被其他研究人员直接采用。本文件还解释了个别成分和步骤的重要性，包括用于IP25定量的内部标准、为简化后续分析而对沉积物提取物进行纯化，以及一些关键的分析考虑因素，特别是在使用质谱学方法进行检测和定量时。通过对加拿大北极群岛(CAA)西部两个邻近地点的沉积物资料中IP25的分析，说明了SOP的应用。在第一个案例中(富兰克林湾)，沉积物材料被均化，并使用等分来证明SOP的重现性，并在研究其他岩心时提供适当的参考材料。在第二个案例中(阿蒙森湾中部)，IP25浓度表现出很大的变化，这与以前对CAA其他区域沉积物岩心的观测结果一致。提出了进一步的实验考虑，允许将沉积IP25浓度转换为时间通量，这可能对古海冰研究更有用。
IP25 is a highly branched isoprenoid lipid biomarker that is produced by some Arctic sea ice diatoms in the spring. The presence of IP25 in marine sediments has previously been used as a proxy measure of past spring sea ice occurrence in the Arctic. Here, a reliable analytical procedure for the reproducible extraction, identification and quantification of IP25 from marine sediments is presented for the first time. This protocol represents a Standard Operating Procedure (SOP) that should be straightforward to adopt by other researchers in the future. This paper also explains the significance of individual components and steps, including the internal standards used for quantification of IP25, the purification of sediment extracts to simplify the subsequent analysis and some key analytical considerations, especially when mass spectrometric methods are used for detection and quantification. The application of the SOP is illustrated with the analysis of IP25 in sediment material obtained from two nearby locations in the western region of the Canadian Arctic Archipelago (CAA). In the first case (Franklin Bay), sediment material was homogenised and aliquots used to demonstrate the reproducibility of the SOP and to provide a suitable reference material when studying other cores. In the second case (central Amundsen Gulf), IP25 concentrations were shown to be quite variable, consistent with observations reported previously for sediment cores from other regions of the CAA. Further experimental considerations are presented that permit the conversion of sedimentary IP25 concentrations into temporal fluxes that are probably more useful for palaeo sea ice studies.