Standardization of Second-Order Chromatographic/Spectroscopic Data for Optimum Chemical Analysis

Prazen, Bryan J.; Synovec, Robert E.; Kowalski, Bruce R.

doi:10.1021/ac9706335

Cited by 132 publications

(98 citation statements)

References 27 publications

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“…Background was subtracted by taking the difference of the matrix and a matrix of the same size containing only baseline noise. Prior to applying GRAM and integration, each sample matrix was retention time aligned to the calibration standard using a previously developed algorithm [31]. The number of chemical components (analytes) used in the GRAM analyses was one for the first set of experiments and four for the second.…”

Section: Methodsmentioning

confidence: 99%

“…These requirements are attained when the detector and chromatograph behave linearly, when each analyte has some separation on both columns, and when retention times remain constant between the sample and the standard, or are made constant by an objective alignment procedure [31]. For the experiments reported in this manuscript, these conditions were met.…”

Section: Theorymentioning

confidence: 99%

See 1 more Smart Citation

Enhancing the Limit of Detection for Comprehensive Two-Dimensional Gas Chromatography (GC×GC) using Bilinear Chemometric Analysis

Fraga¹,

Prazen²,

Synovec³

2000

J. High Resol. Chromatogr.

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Section: Methodsmentioning

confidence: 99%

Section: Theorymentioning

confidence: 99%

Enhancing the Limit of Detection for Comprehensive Two-Dimensional Gas Chromatography (GC×GC) using Bilinear Chemometric Analysis

Fraga¹,

Prazen²,

Synovec³

2000

J. High Resol. Chromatogr.

Self Cite

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“…There have been various approaches to this end; for example, maximizing agreement between data profiles [5], in rank with a target [6], or of segmented profiles to their target [7]. Other examples include more flexible shaping techniques such as time-warping [8][9][10] or a gradient-based motion estimation [11,12].…”

Section: Introductionmentioning

confidence: 99%

Warped factor analysis

Hong

2009

Journal of Chemometrics

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Shifted factor analysis (SFA) is designed to fit overall position shifts of sequential factors as well as the variation of factor weights. SFA is one kind of nonlinear generalization of linear factor models such as the two-mode principal component model and the three-mode Parafac model. Warped factor analysis (WFA), presented here, further generalizes SFA so that it fits factor variation due to not only the position shifts and the systematic weighting but also more flexible shape changes of sequential factors. A quasi alternating least squares (ALS) procedure is developed for WFA, using a simplified warping of segmented sequential factors. The most unique property of WFA is that it allows sequential factors to change shape distinctively, which is unlike what is implicitly assumed in mapping of data profiles, namely that sequential factors change shape together. Unlike the two-mode factor/component models, two-mode SFA was empirically shown to yield an essentially unique solution, using the additional sources of information provided by fitting systematic position shifts. Likewise, factors recovered by two-mode WFA are likely to be essentially unique due to the systematic shape variance fit by the model, provided that the data contain sufficient sources of shape variation.

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“…In a first group, advantage of the matrix data structure is taken: rank alignment (RA) [45,46] and iterative target transformation factor analysis (ITTFA) [47,48]. In a second group, the maximum correlation between chromatograms is sought: the so-called ChromAlign algorithm [49] and correlation optimized warping (COW) [50][51][52][53].…”

Section: Time Shift Correctionmentioning

confidence: 99%

Chemometric strategies for enhancing the chromatographic methodologies with second-order data analysis of compounds when peaks are overlapped

Goicoechea

Culzoni

García

et al. 2011

Talanta

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This overview covers the different chemometric strategies linked to chromatographic methodologies that have been used and presented in the recent literature to cope with problems related to incomplete separation, the presence of unexpected components in the sample, matrix effect and changes in the analytical signal due to pre-treatment of sample.Among the different chemometric strategies it focuses on pre-treatment of data to correct background and time shift of chromatographic peaks and the use of second-order algorithms to cope with overlapping peaks from analytes or from analytes and interferences in liquid chromatography coupled to diode array, fast-scanning fluorescence spectroscopy and mass spectrometry detectors.Finally the review presents the strategies used to deal with changes in the analytical response as result of matrix effect in liquid and gas chromatography, as well as the use of standardization strategies to correct modifications in the analytical signal as a consequence of sample pre-treatment in liquid chromatography.

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Standardization of Second-Order Chromatographic/Spectroscopic Data for Optimum Chemical Analysis

Cited by 132 publications

References 27 publications

Enhancing the Limit of Detection for Comprehensive Two-Dimensional Gas Chromatography (GC×GC) using Bilinear Chemometric Analysis

Enhancing the Limit of Detection for Comprehensive Two-Dimensional Gas Chromatography (GC×GC) using Bilinear Chemometric Analysis

Warped factor analysis

Chemometric strategies for enhancing the chromatographic methodologies with second-order data analysis of compounds when peaks are overlapped

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