Sample preparation effects on stable C and N isotope values: a comparison of methods in Arctic marine food web studies
Sample preparation effects on stable C and N isotope values: a comparison of methods in Arctic marine food web studies
复制标题
样品制备对稳定 C 和 N 同位素值的影响：北极海洋食物网研究方法的比较
DOI：
10.3354/meps328017
复制
发表时间：
2006
影响因子：
2.5
通讯作者：
I. Johansen
中科院分区：
文献类型：
--
作者：
J. Søreide;Tobias Tamelander;H. Hop;K. Hobson;I. Johansen
We compared effects of different sample preparation techniques on the stable carbon and nitrogen isotope values of fish muscle, whole crustaceans and particulate organic matter (POM). Comparisons were also made to untreated (i.e. dried and homogenised) samples. Relatively carbon- ate-rich samples treated with weak acid (0.1 N HCl), either by quickly wetting or acid dampening, were on average 1.3‰ more enriched in 13 C than duplicates soaked in 2 N HCl for 5 min, indicating incomplete carbonate removal with the weaker acid. In comparison, no differences in δ 15 N values were found between acid treatments, and a following water rinse had no effect on the δ 13 C or δ 15 N values. Chloroform-methanol (2:1 by volume) extraction overnight removed less lipids than Soxhlet extraction with 7% methanol in dichloromethane for 2 h, resulting in ~1.2‰ difference in δ 13 C values between treatments of lipid-rich duplicates. Different lipid-extraction methods did not lead to consis- tent differences in δ 15 N values, however. Depending on the lipid and carbonate content, untreated samples were depleted in 13 C by 0.8 to 4.4‰ and in 15 N by 0.6 to 1.4‰ compared to treated dupli- cates. We conclude that δ 13 C and δ 15 N values of samples with low lipid and carbonate content are highly comparable among studies regardless of pre-treatment methods, whereas the δ 13 C values of relatively lipid- and/or carbonate-rich samples must be carefully considered based on the pre- treatment applied to samples. In comparison, δ 15 N values are relatively robust to differences in car- bonate and lipid-removal methods, and δ 15 N values of untreated vs. carbonate- and lipid-treated samples are comparable within ±1.0‰.
