Analysis of Alkenone Unsaturation Indices with Fast Gas Chromatography/Time-of-Flight Mass Spectrometry
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- 作者：J. Hefter
- 刊名：Analytical Chemistry
- 出版年：2008
- 出版时间：March 15, 2008
- 年：2008
- 卷：80
- 期：6
- 页码：2161 - 2170
- 全文大小：276K
- 年卷期：v.80,no.6(March 15, 2008)
- ISSN：1520-6882
文摘
Extensively purified C37 alkenone references and mixturesthereof were analyzed by gas chromatography/flame ionization detection (GC/FID) and fast gas chromatography/time-of-flight mass spectrometry (GC/TOF-MS), to establish the latter as an alternative, fast, and reliable analysismethod for alkenone unsaturation indices (
). Thisindex is a tool for past sea surface temperature reconstructions with extensive use in paleoclimate and paleoceanographic research. TOF-MS was chosen because ofits unique capability to acquire full-range spectra at highdata rates (up to 500 spectra s-1) and to producehomogeneous spectra across a gaschromatographic peak,allowing faster separations than conventional GC/MS andthe employment of enhanced peak deconvolution algorithms. Analysis time per sample could be reduced to runtimes of <10 min, i.e., by a factor of ~10 compared toconventional GC/FID (90-100 min) methods. However,
values from GC/TOF-MS showed deviations fromthose obtained by GC/FID, resulting from sensitivitydifferences between the C37:2 and C37:3 alkenone whenanalyzed by GC/TOF-MS. A solution to this bias ispresented by determining compound-specific linear response factor equations to derive sensitivity ratios (SR)that allow conversion of GC/TOF-MS values into calibrated GC/FID data. Using alkenone mixtures of knowncomposition and a variety of samples from natural environments, the applicability of this approach is demonstrated.
). Thisindex is a tool for past sea surface temperature reconstructions with extensive use in paleoclimate and paleoceanographic research. TOF-MS was chosen because ofits unique capability to acquire full-range spectra at highdata rates (up to 500 spectra s-1) and to producehomogeneous spectra across a gaschromatographic peak,allowing faster separations than conventional GC/MS andthe employment of enhanced peak deconvolution algorithms. Analysis time per sample could be reduced to runtimes of <10 min, i.e., by a factor of ~10 compared toconventional GC/FID (90-100 min) methods. However, values from GC/TOF-MS showed deviations fromthose obtained by GC/FID, resulting from sensitivitydifferences between the C37:2 and C37:3 alkenone whenanalyzed by GC/TOF-MS. A solution to this bias ispresented by determining compound-specific linear response factor equations to derive sensitivity ratios (SR)that allow conversion of GC/TOF-MS values into calibrated GC/FID data. Using alkenone mixtures of knowncomposition and a variety of samples from natural environments, the applicability of this approach is demonstrated.