Two-Dimensional Correlation Optimized Warping Algorithm for Aligning GCxGC-MS Data

Anal. Chem., 80, 8, 2664 - 2671, 2008, 10.1021/ac7024317  

Abstract

A two-dimensional (2-D) correlation optimized warping (COW) algorithm has been developed to align 2-D gas chromatography coupled with time-of-flight mass spectrometry (GC×GC/TOF-MS) data. By partitioning raw chromatographic profiles and warping the grid points simultaneously along the first and second dimensions on the basis of applying a one-dimensional COW algorithm to characteristic vectors, nongrid points can be interpolatively warped. This 2-D algorithm was directly applied to total ion counts (TIC) chromatographic profiles of homogeneous chemical samples, i.e., samples including mostly identical compounds. For heterogeneous chemical samples, the 2-D algorithm is first applied to certain selected ion counts chromatographic profiles, and the resultant warping parameters are then used to warp the corresponding TIC chromatographic profiles. The developed 2-D COW algorithm can also be applied to align other 2-D separation images, e.g., LC×LC data, LC×GC data, GC×GC data, LC×CE data, and CE×CE data.

Dabao Zhang, Xiaodong Huang, Fred E. Regnier, and Min Zhang