Effects of lipid extraction and different collagen extraction methods on archaeological fish bones and its implications for fish bone diagenesis
Effects of lipid extraction and different collagen extraction methods on archaeological fish bones and its implications for fish bone diagenesis
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DOI：
10.1016/j.jasrep.2018.05.026
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发表时间：
2018-08-01
影响因子：
1.6
通讯作者：
Weber, Andrzej W.
中科院分区：
文献类型：
--
作者：
Tsutaya, Takumi;Takahashi, Tomonari;Weber, Andrzej W.
从考古鱼骨中提取的明胶通常显示出相对较高的碳氮比，据推测是由脂质或腐殖质污染引起的。脂质提取和不同胶原蛋白提取方法对现代鱼骨的影响已有研究，但由于地形学和实验的原因，尚未对考古标本进行系统的研究。本研究研究了胶原提取法中脂质提取和NaOH处理顺序对日本北海道Hamanaka 2遗址（约公元前8年-公元10年）出土的考古鱼骨（n = 30）碳氮稳定同位素分析的影响。从相同的鱼骨亚样本中提取明胶，无论是否采用脂质提取程序，在碳和氮稳定同位素比率、元素浓度、C/N比率和产量方面都没有显著的系统性差异。然而，从保存较差的鳕鱼骨中提取的明胶的稳定同位素比率和元素浓度的再现性降低（产率< 3.5%）。从考古鱼骨中提取的明胶可能含有腐殖质污染物，在提取率越低的明胶中，其影响越大。虽然稳定同位素和C/N比值没有明显变化，但碳和氮原子浓度的变化表明，脱钙后应用NaOH处理可提高提取明胶的纯度。由于这只是一个考古遗址的研究，需要进一步的案例研究来评估鱼骨中的脂质和成岩作用。
Gelatin extracted from archaeological fish bones typically exhibits relatively high C/N ratios, presumed to be caused by contamination with lipids or humic substances. The effects of lipid extraction and different collagen extraction methods applied has been studied on modern fish bones but has never been studied systematically on archaeological specimens because of taphonomic and experimental reasons. In this study, the effects of lipid extraction and order of NaOH treatment in collagen extraction method on carbon and nitrogen stable isotope analysis of archaeological fish bone (n = 30) excavated from the Hamanaka 2 site, Hokkaido, Japan (approximately 8th BC-10th AD) is investigated. Gelatin extracted from the same fish bone subsamples with or without lipid extraction procedure indicates neither significant nor systematic differences in carbon and nitrogen stable isotope ratios, elemental concentrations, C/N ratios, and yield. However, reproducibility of stable isotope ratios and elemental concentrations decrease in gelatin extracted from poorly-preserved cod bones (< 3.5% yield). Gelatin extracted from archaeological fish bones may contain humic contaminants, and its effect becomes greater in gelatin with lower extraction yield. Although there is no significant change in the stable isotope and C/N ratios, change in atomic concentration of carbon and nitrogen suggests that the purity of extracted gelatin increases when NaOH treatment is applied after decalcification. Because this is only a study from one archaeological site, further case studies that evaluate lipids and diagenesis in fish bones are required.