An Efficient Method for Isolating Individual Long-Chain Alkenones for Compound-Specific Hydrogen Isotope Analysis
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- 作者：William J. D'Andrea ; Zhonghui Liu ; Marcelo Da Rosa Alexandre ; Sarah Wattley ; Timothy D. Herbert ; Yongsong Huang
- 刊名：Analytical Chemistry
- 出版年：2007
- 出版时间：May 1, 2007
- 年：2007
- 卷：79
- 期：9
- 页码：3430 - 3435
- 全文大小：152K
- 年卷期：v.79,no.9(May 1, 2007)
- ISSN：1520-6882
文摘
Hydrogen isotope ratios (2H/H or D/H) of long-chainunsaturated ketones (alkenones) preserved in lake andmarine sediments hold great promise for paleoclimatestudies. However, compound-specific hydrogen isotopeanalysis of individual alkenones has not been possible dueto chromatographic coelution of alkenones with the samecarbon chain length but different numbers of doublebonds. Published studies have only reported the 
Dvalues of the mixture of coeluting alkenones. We developed an efficient procedure to isolate individual alkenonesbased on double-bond numbers using silica gel impregnated with silver nitrate. The chromatographic procedureis simple, inexpensive, and highly reproducible, offers87-100% sample recovery, and allows for the first timehydrogen isotopic measurement on individual alkenones.D values of specific di-, tri- and tetraunsaturated C37alkenones produced by an Emiliania huxleyi culture,as well as those isolated from Greenland lake sediments,differ consecutively by 43-65 ”. These findings suggestthat alkenones with different numbers of carbon-carbondouble bonds express significantly different D values andthat coelution of different alkenones may lead to erroneous source water D reconstructions. Our alkenoneisolation approach opens a new avenue for paleoclimatereconstructions using hydrogen isotope ratios of individual alkenones.
Dvalues of the mixture of coeluting alkenones. We developed an efficient procedure to isolate individual alkenonesbased on double-bond numbers using silica gel impregnated with silver nitrate. The chromatographic procedureis simple, inexpensive, and highly reproducible, offers87-100% sample recovery, and allows for the first timehydrogen isotopic measurement on individual alkenones.D values of specific di-, tri- and tetraunsaturated C37alkenones produced by an Emiliania huxleyi culture,as well as those isolated from Greenland lake sediments,differ consecutively by 43-65 ”. These findings suggestthat alkenones with different numbers of carbon-carbondouble bonds express significantly different D values andthat coelution of different alkenones may lead to erroneous source water D reconstructions. Our alkenoneisolation approach opens a new avenue for paleoclimatereconstructions using hydrogen isotope ratios of individual alkenones.