A comprehensive two-dimensional retention time alignment algorithm to enhance chemometric analysis of comprehensive two-dimensional separation data
A comprehensive two-dimensional retention time alignment algorithm to enhance chemometric analysis of comprehensive two-dimensional separation data
复制标题
DOI：
10.1021/ac0511142
复制
发表时间：
2005-12-01
影响因子：
7.4
通讯作者：
Synovec, RE
中科院分区：
文献类型：
--
作者：
Pierce, KM;Wood, LF;Synovec, RE
使用新的索引方案开发了一种全面的二维（21）保留时间比对算法。该算法被称为综合性的，因为它的功能是在两个维度上校正整个色谱图，并保留两个维度上的分离信息。虽然该算法是通过校正全面的二维气相色谱（GC x GC）数据来演示的，但该算法旨在校正所有形式的二维分离中的偏移，例如LC x LC、LC x CE、CE x CE和LC x GC。将该2D比对算法应用于由（1）三种22组分对照混合物、（2）三种汽油样品和（3）三种柴油样品的重复GC X GC分离组成的三个不同数据集。使用略微不同的温度或压力程序收集三个数据集，以在原始数据中产生显著的保留时间偏移，然后在数据集的全面2D对齐后证明该偏移的后续校正。使用来自三种22组分对照混合物的三十个12分钟GC x GC分离来评估2D对准性能（10次运行/混合物）。第一柱保留时间的平均标准偏差从0.020 min（对齐前）提高到0.004 min（对齐后），提高了5倍。同时，第二柱保留时间的平均标准偏差从3.5 ms（对齐前）提高4倍至0.8 ms（对齐后）。30个对照混合物色谱图的对齐需要20分钟。还研究了二维对齐后GC x GC数据的定量完整性。对于所有30次重复测定，测定三种22组分混合物中所有组分的平均积分信号。比对前后各组分的积分信号的平均百分比差异为2.6%。将奇异值分解（SVD）应用于比对前后的22组分对照混合物数据，以显示数据的三线性恢复，因为三线性有利于化学计量学分析。通过对所有三个数据集（对照混合物、汽油样品和柴油样品）应用全面的2D保留时间对齐，主成分分析（PCA）的分类得到了显著改善，从而实现了100%准确的分数聚类。
A comprehensive two-dimensional (21)) retention time alignment algorithm was developed using a novel indexing scheme. The algorithm is termed comprehensive because it functions to correct the entire chromatogram in both dimensions and it preserves the separation information in both dimensions. Although the algorithm is demonstrated by correcting comprehensive two-dimensional gas chromatography (GC x GC) data, the algorithm is designed to correct shifting in all forms of 2D separations, such as LC x LC, LC x CE, CE x CE, and LC x GC. This 2D alignment algorithm was applied to three different data sets composed of replicate GC x GC separations of (1) three 22-component control mixtures, (2) three gasoline samples, and (3) three diesel samples. The three data sets were collected using slightly different temperature or pressure programs to engender significant retention time shifting in the raw data and then demonstrate subsequent corrections of that shifting upon comprehensive 2D alignment of the data sets. Thirty 12-min GC x GC separations from three 22-component control mixtures were used to evaluate the 2D alignment performance (10 runs/mixture). The average standard deviation of first column retention time improved 5-fold from 0.020 min (before alignment) to 0.004 min (after alignment). Concurrently, the average standard deviation of second column retention time improved 4-fold from 3.5 ms (before alignment) to 0.8 ms (after alignment). Alignment of the 30 control mixture chromatograms took 20 min. The quantitative integrity of the GC x GC data following 2D alignment was also investigated. The mean integrated signal was determined for all components in the three 22-component mixtures for all 30 replicates. The average percent difference in the integrated signal for each component before and after alignment was 2.6%. Singular value decomposition (SVD) was applied to the 22-component control mixture data before and after alignment to show the restoration of trilinearity to the data, since trilinearity benefits chemometric analysis. By applying comprehensive 2D retention time alignment to all three data sets (control mixtures, gasoline samples, and diesel samples), classification by principal component analysis (PCA) substantially improved, resulting in 100% accurate scores clustering.