Statistical inference of mass channel purity from Fisher ratio analysis using comprehensive two-dimensional gas chromatography with time of flight mass spectrometry data

Ochoa, Grant S.; Prebihalo, Sarah E.; Reaser, Brooke C.; Marney, Luke C.; Synovec, Robert E.

doi:10.1016/j.chroma.2020.461401

Cited by 23 publications

(31 citation statements)

References 46 publications

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“…For each analyte in each hit list, the peak area in each sample was quantified using the m/z associated with the top F-ratio, which has been shown to be selective, generally free from interferences. 31 A ttest (α = 0.05) and concentration ratio between the clean and strong PTD classes ([strong]/[clean]) were also calculated. Tentative compound identifications were given if the mass spectra were matched to a NIST11 library standard (National Institute of Standard and Technology, MD, USA) with a match value (MV) 32 greater than 800, which is standardly defined as sufficient to declare a match.…”

Section: ■ Materials and Methodsmentioning

confidence: 99%

Analytical Determination of the Severity of Potato Taste Defect in Roasted East African Arabica Coffee

Cain

Haughn

Purcell

et al. 2021

J. Agric. Food Chem.

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The quality of East African coffee beans has been significantly reduced by a flavor defect known as potato taste defect (PTD) due to the presence of 2-isopropyl-3-methoxypyrazine (IPMP) and 2-isobutyl-3-methoxypyrazine (IBMP). Therefore, the aims of this study were to determine the correlation between these methoxypyrazines and the severity of odor attributed to PTD and discover additional analytes that may be correlated with PTD using Fisher ratio analysis, a supervised discovery-based data analysis method. Specialty ground roasted coffees from East Africa were classified as clean (i.e., no off-odor), mild, medium, or strong PTD. For the samples examined, IPMP was found to discriminate between non-defective and defective samples, while IBMP did not do so. Samples affected by PTD exhibited a wide range of IPMP concentration (1.6–529.9 ng/g). Except for one sample, the IPMP concentration in defective samples was greater than the average IPMP concentration in the non-defective samples (2.0 ng/g). Also, an analysis of variance found that IPMP concentrations were significantly different based on the severity of odor attributed to PTD (p < 0.05). Fisher ratio analysis discovered 21 additional analytes whose concentrations were statistically different based on the severity of PTD odor (p < 0.05). Generally, analytes that were positively correlated with odor severity generally had unpleasant sensory descriptions, while analytes typically associated with desirable aromas were found to be negatively correlated with odor severity. These findings not only show that IPMP concentration can differentiate the severity of PTD but also that changes in the volatile analyte profile of coffee beans induced by PTD can contribute to odor severity.

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Section: ■ Materials and Methodsmentioning

confidence: 99%

Analytical Determination of the Severity of Potato Taste Defect in Roasted East African Arabica Coffee

Cain

Haughn

Purcell

et al. 2021

J. Agric. Food Chem.

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“…First, each hit “pin” location in the 2D separation space is used to target the quantitative analysis for each analyte. Second, because the magnitude of the F-ratio correlates with m / z purity, this aids in m / z selection for quantification . For each hit, a pure m / z , generally associated with the largest F-ratio, was used to calculate the relative signal for each sample.…”

Section: Methodsmentioning

confidence: 99%

“…53 Top-down quantitative analysis of metabolites in the hit lists was performed using an in-house signal measurement algorithm, as described in Figure S1, that functionally applies the "two-step" method on the GC × GC data in the unfolded form, 42 by performing 2 D peak apex finding for pure m/z followed by summing the peaks heights for each analyte. 54 The algorithm uses key information gleaned from each FRA to determine the signal for given hits for each chromatogram. First, each hit "pin" location in the 2D separation space is used to target the quantitative analysis for each analyte.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

“…Second, because the magnitude of the F-ratio correlates with m/z purity, this aids in m/z selection for quantification. 54 For each hit, a pure m/z, generally associated with the largest F-ratio, was used to calculate the relative signal for each sample. Using the two-step method, determination of m/z purity was further assessed by visual inspection of the raw unfolded data using the ChromaTOF software provided with the instrument platform.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

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Control-Normalized Fisher Ratio Analysis of Comprehensive Two-Dimensional Gas Chromatography Time-of-Flight Mass Spectrometry Data for Enhanced Biomarker Discovery in a Metabolomic Study of Orthopedic Knee-Ligament Injury

et al. 2020

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An innovative form of Fisher ratio (F-ratio) analysis (FRA) is developed for use with comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC × GC−TOFMS) data and applied to the investigation of the changes in the metabolome in human plasma for patients with injury to their anterior cruciate ligament (ACL). Specifically, FRA provides a supervised discovery of metabolites that express a statistically significant variance in a two-sample class comparison: patients and healthy controls. The standard F-ratio utilizes the between-class variance relative to the pooled within-class variance. Because standard FRA is adversely impacted by metabolites expressed with a large within-class variance in the patient class, "control-normalized FRA" has been developed to provide complementary information, by normalizing the between-class variance to the variance of the control class only. Thirty plasma samples from patients who recently suffered from an ACL injury, along with matched controls, were subjected to GC × GC−TOFMS analysis. Following both standard and control-normalized FRA, the concentration ratio for the top 30 "hits" in each comparison was obtained and then t-tested for statistical significance. Twenty four out of 30 metabolites plus the therapeutic agent, naproxen (24/30), passed the t-test for the control-normalized FRA, which included 8/24 unique to control-normalized FRA and 16/24 in common with the standard FRA. Likewise, standard FRA provided 21/30 metabolites passing the t-test, with 5/21 undiscovered by control-normalized FRA. The complementary information obtained by both F-ratio analyses demonstrates the general utility of the new approach for a variety of applications.

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“…Nevertheless, the interpretation and quantification of peak overlapping in the 3D separation plane required the use of parallel factor analysis as decomposition tool 39 . In order to tackle this bottleneck, a more automatable approach was proposed and used to process 2D chromatographic data, consisting in the isolation of pure m/z combining the measure of lack of fit metric (for peak purity), F‐ratio, and P ‐values; therefore avoiding the need for signal decomposition algorithm 40 …”

Section: Software and Analysis Workflowsmentioning

confidence: 99%

30^th Anniversary of comprehensive two‐dimensional gas chromatography: Latest advances

Zanella

Focant

Franchina

2021

Analytical Science Advances

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In this review, we report on the latest (2020‐Early 2021) instrumental advances and applications of comprehensive two‐dimensional gas chromatography (GC×GC), including its hyphenation with novel upstream or downstream processes (sample preparation approaches or detection technologies). We also discuss software and analysis workflow developments necessary to elaborate the dense chemical information obtained. Thirty years after its inception, the use of GC×GC, as the main analytical tool or as a complementary platform, is undoubtedly shifting toward more applied challenges in a vast breadth of applications. Therefore, we consider the major fields (energy, fuel, foodstuff, plant, biological, and environmental) in which GC×GC has been successfully used, discussing some of the recent innovative research works.

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Statistical inference of mass channel purity from Fisher ratio analysis using comprehensive two-dimensional gas chromatography with time of flight mass spectrometry data

Cited by 23 publications

References 46 publications

Analytical Determination of the Severity of Potato Taste Defect in Roasted East African Arabica Coffee

Analytical Determination of the Severity of Potato Taste Defect in Roasted East African Arabica Coffee

Control-Normalized Fisher Ratio Analysis of Comprehensive Two-Dimensional Gas Chromatography Time-of-Flight Mass Spectrometry Data for Enhanced Biomarker Discovery in a Metabolomic Study of Orthopedic Knee-Ligament Injury

30^th Anniversary of comprehensive two‐dimensional gas chromatography: Latest advances

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Statistical inference of mass channel purity from Fisher ratio analysis using comprehensive two-dimensional gas chromatography with time of flight mass spectrometry data

Cited by 23 publications

References 46 publications

Analytical Determination of the Severity of Potato Taste Defect in Roasted East African Arabica Coffee

Analytical Determination of the Severity of Potato Taste Defect in Roasted East African Arabica Coffee

Control-Normalized Fisher Ratio Analysis of Comprehensive Two-Dimensional Gas Chromatography Time-of-Flight Mass Spectrometry Data for Enhanced Biomarker Discovery in a Metabolomic Study of Orthopedic Knee-Ligament Injury

30th Anniversary of comprehensive two‐dimensional gas chromatography: Latest advances

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Product

Resources

About

30^th Anniversary of comprehensive two‐dimensional gas chromatography: Latest advances