Chau Thuan H, Tipple Brett J, Hu Lihai, Fernandez Diego P, Cerling Thure E, Ehleringer James R, Chesson Lesley A
IsoForensics, Inc., 421 Wakara Way, Suite 100, Salt Lake City, UT, 84108, USA.
Department of Biology, University of Utah, 257 S 1400 E, Salt Lake City, UT, 84112, USA.
Rapid Commun Mass Spectrom. 2017 Mar 30;31(6):583-589. doi: 10.1002/rcm.7822.
Oxygen isotope ratios (δ O values) of hair largely reflect features of regional hydrology while strontium isotope ratios ( Sr/ Sr) are thought to reflect bedrock geology; combination of both isotope signatures may provide greater capacity for determining provenance and reconstructing travel history of an organism. To test this hypothesis, we compared the O-Sr isotope profiles of hair from domestic horses with known residency histories.
Tail hairs were collected from a pair of horses pastured together for a period of 16 months, one of which lived in a different location for the 8 months prior. Hair samples were washed with solvents to remove external contaminants prior to sequential sampling for δ O and Sr/ Sr analysis via TC/EA-IRMS and MC-ICP-MS, respectively. Hair digests were concentrated and analyzed employing low-flow natural aspiration to measure Sr/ Sr.
Tail hair from the control and transported horses had mean δ O values of 11.25 ± 1.62 ‰ and 10.96 ± 1.53 ‰, and mean Sr/ Sr of 0.7101 ± 0.0006 and 0.7109 ± 0.0020, respectively. The δ O and Sr/ Sr profiles for the control and transported horses were indistinguishable when they were pastured together. The Sr/ Sr profiles were significantly different during the period that the horses were living apart, while the δ O values were indistinguishable during that period.
By comparing the O-Sr isotope profiles of a control and transported horse, we investigated isotopic signal(s) potentially useful for reconstructing travel histories via high-resolution sequential sampling along single strands of tail hair. Improved analytical capabilities allowed for extremely low Sr abundance samples to be analyzed for Sr/ Sr and proved capable of resolving a horse's movement between distinct regions. Copyright © 2017 John Wiley & Sons, Ltd.
毛发的氧同位素比率（δ¹⁸O值）在很大程度上反映了区域水文特征，而锶同位素比率（⁸⁷Sr/⁸⁶Sr）被认为反映了基岩地质情况；两种同位素特征的结合可能为确定生物体的来源和重建其迁徙历史提供更强的能力。为了验证这一假设，我们比较了具有已知居住历史的家养马毛发的氧 - 锶同位素谱。
从一对共同放牧了16个月的马身上采集尾毛，其中一匹马在此之前的8个月生活在不同地点。在通过TC/EA - IRMS和MC - ICP - MS分别对毛发样本进行δ¹⁸O和⁸⁷Sr/⁸⁶Sr分析的顺序采样之前，先用溶剂清洗毛发样本以去除外部污染物。毛发消化液经过浓缩后，采用低流量自然进样法进行分析以测量⁸⁷Sr/⁸⁶Sr。
对照马和迁徙马的尾毛平均δ¹⁸O值分别为11.25±1.62‰和10.96±1.53‰，平均⁸⁷Sr/⁸⁶Sr分别为0.7101±0.0006和0.7109±0.0020。当对照马和迁徙马共同放牧时，它们的δ¹⁸O和⁸⁷Sr/⁸⁶Sr谱无法区分。在马分开生活期间，⁸⁷Sr/⁸⁶Sr谱有显著差异，而在此期间δ¹⁸O值无法区分。
通过比较对照马和迁徙马的氧 - 锶同位素谱，我们研究了通过沿单根尾毛进行高分辨率顺序采样来重建迁徙历史可能有用的同位素信号。改进的分析能力使得能够对极低锶含量的样本进行⁸⁷Sr/⁸⁶Sr分析，并证明能够分辨马在不同区域之间的移动。版权所有©2017约翰·威利父子有限公司。
