Frontiers of Two-Dimensional Correlation Spectroscopy. Part 1. New concepts and noteworthy developments

Noda, Isao

doi:10.1016/j.molstruc.2014.01.025

Cited by 137 publications

(72 citation statements)

References 291 publications

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“…The obtained set of spectra observed as a function of the perturbation variable is then transformed into a set of 2D correlation spectra by a form of cross correlations, which define structural relationships (Noda and Ozaki, 2004). For an in-depth understanding of this concept, readers are encouraged to consult the works of Noda and Ozaki (2004), Noda (2014aNoda ( , 2014b. In environmental research, the use of 2D correlation spectroscopy is still in its infancy.…”

Section: Introductionmentioning

confidence: 99%

Investigating the water-soluble organic functionality of urban aerosols using two-dimensional correlation of solid-state 13C NMR and FTIR spectral data

Duarte

Freire

Duarte

2015

Atmospheric Environment

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Section: Introductionmentioning

confidence: 99%

Investigating the water-soluble organic functionality of urban aerosols using two-dimensional correlation of solid-state 13C NMR and FTIR spectral data

Duarte

Freire

Duarte

2015

Atmospheric Environment

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“…The time dependence of VOC uptake into the polymer film provides another dimension that can be exploited to deconvolute mixture spectra, for example by analyzing segmented data blocks [47]. To demonstrate the ability of our system to identify VOCs within a mixture, we have acquired time series spectra for VOC uptake into the polymer film from the headspace of a mixture containing equal masses of ethyl acetate, isovaleric acid, and 2-amino acetophenone.…”

Section: Resultsmentioning

confidence: 99%

“…It is routinely used in nuclear magnetic resonance (NMR) spectroscopy and has also been extensively applied to vibrational spectroscopy [44][45][46][47][48]. The correlation transform provides one dimensional (1D) spectra from which background features are effectively removed.…”

Section: Introductionmentioning

confidence: 99%

Raman system for sensitive and selective identification of volatile organic compounds

Park

Mercer-Smith

et al. 2015

Sensors and Actuators B: Chemical

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a b s t r a c tAnalysis of volatile organic compounds (VOCs) for medical and industrial applications typically requires complex and expensive mass spectrometric systems to achieve the desired sensitivity and specificity. Raman spectroscopy enables specific compound identification based on distinct spectral fingerprints but traditionally has low sensitivity. We have developed a novel Raman system that provides VOC detection in the low ppm range. VOCs from the gas phase are absorbed and enriched in a thin polymer film coated on the surface of an optical sensor element. The VOC enriched polymer film is probed with evanescent wave excitation and optimized Raman signal collection. The herein described Raman sensor is low-cost, robust, readily manufacturable, and capable of providing high sensitivity without the nanostructured sensors required for surface enhanced Raman spectroscopy. To suppress background noise and interfering spectral features while improving our ability to resolve VOC mixture spectra, we applied two-dimensional (2D) correlation analysis to time series spectra acquired during VOC absorption into the polymer film. We established proof of principle through analysis of known VOC biomarkers for selected bacterial pathogens. The system enabled VOC detection with significantly higher sensitivity than commercial Raman probes. We observed good agreement between spectra of VOCs in the thin film obtained after 2D correlation analysis, and of pure VOCs using a commercial probe. Mixture spectra were further de-convoluted based on the off-diagonal peaks observable in the 2D Raman spectrum in conjunction with segmented data analysis. We anticipate that this system can be applied to a variety of medical, industrial, and biodefense applications.

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“…Covariance transformations were applied to raw data sets as well as pre-processed data. Covariance NMR and covariance processing methods have been recently reviewed in great detail [1][2][3][4][5][6][7]. Due to the purely mathematical nature, the computer power and the algorithms applied determine the speed with which covariance spectra can be obtained.…”

Section: Introductionmentioning

confidence: 99%

“…The matrix representation form reveals that Noda´s synchronous matrix Φ, in Eqs. (6) and (16), corresponds to the covariance map according to Eq. (15), if mean centered spectra are the elements of the data matrices giving Φ.…”

Section: Introductionmentioning

confidence: 99%

Homo- and Hetero-Covariance NMR Spectroscopy and Applications to Process Analytical Technology

Jaeger¹,

Legner²

2017

Spectroscopic Analyses - Developments and Applications

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Covariance processing of data and spectra has established itself among the computerbased NMR spectroscopy methodologies to increase sensitivity and resolution and to facilitate spectral analysis. While homo-correlations yield two-dimensional (2D) diagonally symmetric or antisymmetric spectra, hetero-covariance transformations allow to transfer NMR chemical shift information to other spectroscopic techniques, such as near infra-red or Raman. This is visualized as a 2D correlation map, provided a common indirect or perturbation domain, such as time, concentration change, and pressure. Covariance spectra can be generated as synchronous or asynchronous maps. The synchronous map relates the signals of species, e.g., educts and products. The asynchronous spectrum allows to derive the sequential order in which such species occur relative to each other. After a theoretical introduction into covariance NMR, its application in process analytical technology is discussed for wine fermentation, a radical polymerization reaction, a continuous process ethanol production using immobilized yeast, and a Knoevenagel condensation in a microreaction system. The covariance approach is extended toward two perturbation variables and quantitative relationships through PARAFAC kernel analysis and is illustrated for the preparation of polylactic acid nanocomposites. The advantages and added values of using synchronous and asynchronous spectra to gain process knowledge and control are demonstrated.

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Frontiers of Two-Dimensional Correlation Spectroscopy. Part 1. New concepts and noteworthy developments

Cited by 137 publications

References 291 publications

Investigating the water-soluble organic functionality of urban aerosols using two-dimensional correlation of solid-state 13C NMR and FTIR spectral data

Investigating the water-soluble organic functionality of urban aerosols using two-dimensional correlation of solid-state 13C NMR and FTIR spectral data

Raman system for sensitive and selective identification of volatile organic compounds

Homo- and Hetero-Covariance NMR Spectroscopy and Applications to Process Analytical Technology

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