Chapter 4 Data Acquisition, Visualization, and Analysis

Reichenbach, Stephen E.

doi:10.1016/s0166-526x(09)05504-4

Cited by 11 publications

(12 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…For the diesel chromatograms, phase-shifting, baseline correction, and peak detection were performed . Automated bidirectional peak matching created initial lists of corresponding peaks between all pairs of chromatograms.…”

Section: Methodsmentioning

confidence: 99%

Effectiveness of Global, Low-Degree Polynomial Transformations for GCxGC Data Alignment

Rempe

Reichenbach²,

Qing

et al. 2016

Anal. Chem.

Self Cite

View full text Add to dashboard Cite

As columns age and differ between systems, retention times for comprehensive two-dimensional gas chromatography (GCxGC) may vary between runs. To properly analyze GCxGC chromatograms, it often is desirable to align the retention times of chromatographic features, such as analyte peaks, between chromatograms. Previous work by the authors has shown that global, low-degree polynomial transformation functions, namely affine, second-degree polynomial, and third-degree polynomial, are effective for aligning pairs of two-dimensional chromatograms acquired with dual second columns and detectors (GC×2GC). This work assesses the experimental performance of these global methods on more general GCxGC chromatogram pairs and compares their performance to that of a recent, robust, local alignment algorithm for GCxGC data [ Gros Anal. Chem. 2012 , 84 , 9033 ]. Measuring performance with the root-mean-square (RMS) residual differences in retention times for matched peaks suggests that global, low-degree polynomial transformations outperform the local algorithm given a sufficiently large set of alignment points, and are able to improve misalignment by over 95% based on a lower-bound benchmark of inherent variability. However, with small sets of alignment points, the local method demonstrated lower error rates (although with greater computational overhead). For GCxGC chromatogram pairs with only slight initial misalignment, none of the global or local methods performed well. In some cases with initial misalignment near the inherent variability of the system, these methods worsened alignment, suggesting that it may be better not to perform alignment in such cases.

show abstract

Section: Methodsmentioning

confidence: 99%

Effectiveness of Global, Low-Degree Polynomial Transformations for GCxGC Data Alignment

Rempe

Reichenbach²,

Qing

et al. 2016

Anal. Chem.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The phase-roll operation spirals the data to achieve the desired start position for each 2 D chromatogram [1]. For this chromatogram, phase roll is set to 0.8 s, which leaves the bleed along the bottom of the image.…”

Section: Modulation-cycle Phase Rollmentioning

confidence: 99%

“…The difficulty of detecting and identifying analytes in data from comprehensive two-dimensional gas chromatography with mass spectrometry (GC×GC-MS) ranges from simple, for resolved analytes that have clear spectral signals matched in mass-spectral libraries, to challenging, for coeluted and trace analytes that have obscure or faint signals and ambiguous matching with mass-spectral libraries [1][2][3][4][5]. This case study examines a combination of time-tested and new peak detection techniques, beginning with the 2D drain algorithm that is highly effective for resolved peaks, filtering of those peaks, followed by a new method for predicting true and false peak detections, and combined with a new tool that detects collections of coincident ion-peaks.…”

Section: Introductionmentioning

confidence: 99%

A Data-Challenge Case Study of Analyte Detection and Identification with Comprehensive Two-Dimensional Gas Chromatography with Mass Spectrometry (GC×GC-MS)

et al. 2019

Self Cite

View full text Add to dashboard Cite

This case study describes data analysis of a chromatogram distributed for the 2019 GC×GC Data Challenge for the Tenth Multidimensional Chromatography Workshop (Liege, Belgium). The chromatogram resulted from chemical analysis of a terpene-standards sample by comprehensive two-dimensional chromatography with mass spectrometry (GC×GC-MS). First, several aspects of the data quality are assessed, including detector saturation and oscillation, and operations to prepare the data for analyte detection and identification are described, including phase roll for modulation-cycle alignment and baseline correction to account for the non-zero detector baseline. Then, the case study presents operations for analyte detection with filtering, a new method to flag false detections, interactive review to confirm detected peaks, and ion-peaks detection to reveal peaks that are obscured by noise or coelution. Finally, the case study describes analyte identification including mass-spectral library search with a new method for optimizing spectra extraction, retention-index calibration from preliminary identifications, and expression-based identification checks. Processing of the first 40 min of data detected 144 analytes, 21 of which have at least one percent response, plus an additional 20 trace and/or coeluted analytes.

show abstract

“…Conceptually, the algorithm initiates detection at the apex of a peak and iteratively adds all smaller neighbors until no more smaller points border the peak [10]. The watershed algorithm can be implemented with a priority queue to sort all data points.…”

Section: Watershed Algorithmmentioning

confidence: 99%

Comparative analysis of peak-detection techniques for comprehensive two-dimensional chromatography

Latha

Reichenbach²,

Qing

2011

Journal of Chromatography A

Self Cite

View full text Add to dashboard Cite

Chapter 4 Data Acquisition, Visualization, and Analysis

Cited by 11 publications

References 44 publications

Effectiveness of Global, Low-Degree Polynomial Transformations for GCxGC Data Alignment

Effectiveness of Global, Low-Degree Polynomial Transformations for GCxGC Data Alignment

A Data-Challenge Case Study of Analyte Detection and Identification with Comprehensive Two-Dimensional Gas Chromatography with Mass Spectrometry (GC×GC-MS)

Comparative analysis of peak-detection techniques for comprehensive two-dimensional chromatography

Contact Info

Product

Resources

About