High-speed peak matching algorithm for retention time alignment of gas chromatographic data for chemometric analysis
High-speed peak matching algorithm for retention time alignment of gas chromatographic data for chemometric analysis
复制标题
DOI：
10.1016/s0021-9673(03)00616-2
复制
发表时间：
2003-05-09
影响因子：
4.1
通讯作者：
Synovec, RE
中科院分区：
文献类型：
--
作者：
Johnson, KJ;Wright, BW;Synovec, RE
开发了一种快速保留时间对齐算法作为预处理实用程序，在对使用气相色谱 (GC) 获得的柴油概况数据集进行化学计量分析之前使用。由于当前的化学计量技术无法正确地对数据集中从一个变量转移到另一个变量的信息进行建模，因此色谱图之间的保留时间变化一直是化学计量技术在色谱数据分析中使用的重大障碍。所开发的比对算法被证明可以通过保留化学选择性同时减少色谱图之间的保留时间变化来提高应用于柴油色谱图的模式识别方法的效率，并且在使大量色谱数据分析变得实用的时间尺度上实现这一点。使用新颖的对齐算法和主成分分析 (PCA) 对两组柴油燃料气相色谱图进行了研究。在第一项研究中，比对前 60 个色谱图中相应色谱峰的保留时间在色谱图之间相差多达 300 毫秒。在 42 个色谱图的第二项研究中，相应色谱峰之间显示的保留时间偏移约为 10 秒，并且在与算法对齐之前需要进行粗略的保留时间校正。在这两种情况下，在应用保留时间比对算法之前和之后的重叠色谱图中，算法提供的保留时间精度的提高清晰可见。使用比对算法，在整个给定色谱图中，比对后相应峰保留时间的标准偏差为 17 ms，相当于平均保留时间为 8 分钟时的相对标准偏差为 0.003%。这种保留时间精度比配备电子压力控制的最先进的气相色谱仪最初提供的保留时间精度提高了 5 倍，对于化学计量分析的性能至关重要。保留时间精度的提高并不以牺牲化学选择性为代价，因为 PCA 结果表明基本上所有的化学选择性都得到了保留。在使用 PCA 生成的二维分数空间中，不同组柴油色谱图之间的聚类分辨率在对齐后显着增加。该比对方法对于比对中使用的目标色谱图的缺失或额外峰具有鲁棒性，并且运行速度快，每个 GC 色谱图需要大约 1 s 的计算时间。 (C) 2003 Elsevier Science B.V. 保留所有权利。
A rapid retention time alignment algorithm was developed as a preprocessing utility to be used prior to chemometric analysis of large datasets of diesel fuel profiles obtained using gas chromatography (GC). Retention time variation from chromatogram-to-chromatogram has been a significant impediment against the use of chemometric techniques in the analysis of chromatographic data due to the inability of current chemometric techniques to correctly model information that shifts from variable to variable within a dataset. The alignment algorithm developed is shown to increase the efficacy of pattern recognition methods applied to diesel fuel chromatograms by retaining chemical selectivity while reducing chromatogram-to-chromatogram retention time variations and to do so on a time scale that makes analysis of large sets of chromatographic data practical. Two sets of diesel fuel gas chromatograms were studied using the novel alignment algorithm followed by principal component analysis (PCA). In the first study, retention times for corresponding chromatographic peaks in 60 chromatograms varied by as much as 300 ms between chromatograms before alignment. In the second study of 42 chromatograms, the retention time shifting exhibited was on the order of 10 s between corresponding chromatographic peaks, and required a coarse retention time correction prior to alignment with the algorithm. In both cases, an increase in retention time precision afforded by the algorithm was clearly visible in plots of overlaid chromatograms before and then after applying the retention time alignment algorithm. Using the alignment algorithm, the standard deviation for corresponding peak retention times following alignment was 17 ms throughout a given chromatogram, corresponding to a relative standard deviation of 0.003% at an average retention time of 8 min. This level of retention time precision is a 5-fold improvement over the retention time precision initially provided by a state-of-the-art GC instrument equipped with electronic pressure control and was critical to the performance of the chemometric analysis. This increase in retention time precision does not come at the expense of chemical selectivity, since the PCA results suggest that essentially all of the chemical selectivity is preserved. Cluster resolution between dissimilar groups of diesel fuel chromatograms in a two-dimensional scores space generated with PCA is shown to substantially increase after alignment. The alignment method is robust against missing or extra peaks relative to a target chromatogram used in the alignment, and operates at high speed, requiring roughly 1 s of computation time per GC chromatogram. (C) 2003 Elsevier Science B.V. All rights reserved.