Unique ion filter—A data reduction tool for chemometric analysis of raw comprehensive two‐dimensional gas chromatography‐mass spectrometry data

Abstract

Funding informationNatural Sciences and Engineering Research Council; Genome Canada; Canada Foundation for Innovation Comprehensive gas chromatography with time of flight mass spectrometry is a powerful tool in the analysis of complex samples. Chemometric analysis of raw chromatographic data is more useful in one-and two-dimensional separations relative to peak tables. The data volume from such experiments generally necessitates the use of data reduction tools. Such tools often sacrifice some of the multivariate information in the mass to charge ratio dimension. The unique ion filter reduces the over-redundancy in two-dimensional gas chromatographymass spectrometry data by limiting the data to a few unique/pseudo-unique ions, sub-peaks/slices in the first dimension, and spectra in the second dimension. We explore the performance of this algorithm through careful inspection of two-dimensional gas chromatography-mass spectrometry data before and after application of the filter. A reduction (99%) in the number of variables in a twodimensional gas chromatography-mass spectrometry chromatogram passed on to subsequent analysis was observed. Feature selection times for model optimization reduced from 229 (±13) to 6.8 (±0.5) min when the filter was applied. An estimate of two unique/pseudo-unique ions, one sub-peak in the first dimension and five spectra in the second dimension were considered to provide a true representation of each chromatogram and provided enough information to achieve 100% model prediction accuracy.

Recent Advances in GC×GC and Chemometrics to Address Emerging Challenges in Nontargeted Analysis

“…While these examples demonstrate the benefit of applying PLS-DA to the pixel-level data, it is important to note that this approach can be computationally expensive. To improve the computational time of pixel-based PLS-DA, Adutwum et al developed a data reduction tool for GC×GC data files, which is termed the unique ion filter (UIF) . The UIF reduces the data in a GC×GC-MS chromatogram down to only the retention times and unique m / z around each peak, effectively reducing the size of the data file.…”

“…To improve the computational time of pixel-based PLS-DA, Adutwum et al developed a data reduction tool for GC×GC data files, which is termed the unique ion filter (UIF). 78 The UIF reduces the data in a GC×GC-MS chromatogram down to only the retention times and unique m/z around each peak, effectively reducing the size of the data file. This approach significantly improved PLS-DA by reducing the computational time approximately 30-fold.…”

Analysis on the Three-Dimensional Intervention Mode of Public Art in Rural Culture from the Perspective of 3D Video

“…is method can be divided into the manual method, semiautomatic method, and fully automatic method. e manual method is to manually allocate the depth value for the image/video [4].…”

“…Based on this, we understand that public art is a very broad artistic abstract concept, and there is no speci c de nition of art types. But what is certain is that public art exists in society or public space and has an impact on the broad public and society, which is also an arti cially created behavior or art [3,4].…”