Analysis of alkenone unsaturation indices with fast gas chromatography/time-of-flight mass spectrometry.
Analysis of alkenone unsaturation indices with fast gas chromatography/time-of-flight mass spectrometry.
复制标题
使用快速气相色谱/飞行时间质谱分析烯酮不饱和指数。
DOI：
10.1021/ac702194m
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发表时间：
2008
影响因子：
7.4
通讯作者：
Jens Hefter
中科院分区：
文献类型：
--
作者：
Jens Hefter
采用气相色谱/火焰离子化检测（GC/FID）和快速气相色谱/飞行时间质谱（GC/TOF-MS）对广泛纯化的C37烯酮参考文献及其混合物进行分析，建立后者作为烯酮不饱和指数（U（k’）（37））的替代、快速、可靠的分析方法。该指数是一个重建过去海温的工具，在古气候和古海洋学研究中有广泛的应用。之所以选择TOF-MS，是因为它具有独特的能力，可以以高数据速率（高达500个光谱s(-1)）获得全范围光谱，并在气相色谱峰上产生均匀的光谱，比传统的GC/MS更快地分离，并采用增强的峰反褶积算法。每个样品的分析时间可以减少到小于10分钟的运行时间，即，与传统的GC/FID（90-100分钟）方法相比，减少了大约10倍。然而,% @mt;由于GC/TOF-MS分析C37:2和C37:3烯酮的灵敏度存在差异，GC/TOF-MS分析结果与GC/FID分析结果存在偏差。通过确定化合物特定的线性响应因子方程，得出灵敏度比（SR），从而将GC/TOF-MS值转换为校准的GC/FID数据，从而提出了解决这种偏差的方法。使用已知成分的烯酮混合物和来自自然环境的各种样品，证明了这种方法的适用性。
Extensively purified C37 alkenone references and mixtures thereof 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 analysis method for alkenone unsaturation indices (U(k')(37)). This index is a tool for past sea surface temperature reconstructions with extensive use in paleoclimate and paleoceanographic research. TOF-MS was chosen because of its unique capability to acquire full-range spectra at high data rates (up to 500 spectra s(-1)) and to produce homogeneous spectra across a gaschromatographic peak, allowing faster separations than conventional GC/MS and the employment of enhanced peak deconvolution algorithms. Analysis time per sample could be reduced to run times of <10 min, i.e., by a factor of approximately 10 compared to conventional GC/FID (90-100 min) methods. However, %@mt;sys@%%@ital@%%@bold@%U%@reset@%%@rsf@%%@sx@%37%@be@%%@ital@%k%@rsf@%'%@sxx@%%@mx@% values from GC/TOF-MS showed deviations from those obtained by GC/FID, resulting from sensitivity differences between the C37:2 and C37:3 alkenone when analyzed by GC/TOF-MS. A solution to this bias is presented 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 known composition and a variety of samples from natural environments, the applicability of this approach is demonstrated.