Depth profiling of SBS/PET layered materials using step-scan phase modulation Fourier transform infrared photoacoustic spectroscopy and two-dimensional correlation analysis

The potential of Fourier transform infrared photoacoustic spectroscopy (FT-IR/PAS) for examination of food and the package was demonstrated. Full-fat cheddar cheese slices wrapped in polymer package were chosen as the food sample for analysis. Photoacoustic spectroscopy (PAS) in conjunction with the step-scan and digital signal processing (DSP) function was used to perform depth-profiling studies of the intact sample and package. Well-separated PAS bands of fat and protein were obtained in the spectra of cheddar cheese samples with minimum sample preparation. Cheese samples were kept in a dessicator overnight to minimize the effect of moisture on the PAS spectra. Depth profiling study of the cheese polymer package indicated that there is a diffusion of cheese components into the package during storage.

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Fourier Transform Infrared Photoacoustic Spectroscopy Characterization of Sulfur-Oxygen Species Resulting from the Reaction of SO2 with CaO and CaCO3

Applied Spectroscopy ◽

10.1366/0003702874868151 ◽

1987 ◽

Vol 41 (1) ◽

pp. 120-126 ◽

Cited By ~ 36

Author(s):

Meg A. Martin ◽

Jeffrey W. Childers ◽

Richard A. Palmer

Keyword(s):

Fourier Transform ◽

Photoacoustic Spectroscopy ◽

Depth Profiling ◽

Fourier Transform Infrared ◽

Product Layer ◽

Oxygen Species ◽

Initial Product ◽

Ft Ir ◽

Infrared Photoacoustic Spectroscopy

Fourier transform infrared photoacoustic spectroscopy (FT-IR/PAS) has been used to investigate the reaction of SO2, in He with CaO and CaCO3 particles at temperatures between 25 and 900°C. The reaction of SO2 with CaO occurs at 25°C, while the reaction of CaCO3 with SO2 is first evident at 550°C. The initial product of both of these reactions is CaSO3. The CaSO3 then further reacts with SO2 to form CaSO4, CaS2O3, and CaS at higher temperatures. At 900°C and above, the net production of SO4= and S2O3= is decreased because of the decomposition of SO3=. FT-IR/PAS depth-profiling experiments indicate the formation of a reaction-limiting product layer of SO3= and SO4= from the above reactions on the surface of the CaO and CaCO3 particles.

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Rapid and Nondestructive Detection of Pesticide Residues by Depth-Profiling Fourier Transform Infrared Photoacoustic Spectroscopy

ACS Omega ◽

10.1021/acsomega.8b00339 ◽

2018 ◽

Vol 3 (3) ◽

pp. 3548-3553 ◽

Cited By ~ 3

Author(s):

Gaoqiang Lv ◽

Changwen Du ◽

Fei Ma ◽

Yazhen Shen ◽

Jianmin Zhou

Keyword(s):

Fourier Transform ◽

Photoacoustic Spectroscopy ◽

Pesticide Residues ◽

Depth Profiling ◽

Fourier Transform Infrared ◽

Nondestructive Detection ◽

Infrared Photoacoustic Spectroscopy

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Depth Profile Study of Large-Sized Coal Samples by Fourier Transform Infrared Photoacoustic Spectroscopy

Applied Spectroscopy ◽

10.1366/0003702864509475 ◽

1986 ◽

Vol 40 (2) ◽

pp. 214-217 ◽

Cited By ~ 18

Author(s):

Tiziana Zerlia

Keyword(s):

Fourier Transform ◽

Depth Profile ◽

Photoacoustic Spectroscopy ◽

Modulation Frequency ◽

Fourier Transform Infrared ◽

Qualitative Description ◽

Difference Spectra ◽

Compositional Depth Profile ◽

Ft Ir ◽

Infrared Photoacoustic Spectroscopy

A multidisciplinary approach is demonstrated to elucidate coal weathering at a molecular level. Fourier Transform Infrared Photoacoustic Spectroscopy (FT-IR/PAS) provides a technique for a compositional depth profile of coal by simply varying the modulation frequency (mirror velocity) of the light impinging upon the solid surface. In order that the potential of this technique in this field could be evaluated, large-sized coal samples were examined. The PA difference spectra obtained from the spectra taken at different modulation frequencies (i.e., different depths), on a sample aged in air, demonstrate the appearance of negative features in the CH infrared absorption which are indicative of a coal alteration. Therefore, different coal layers can be distinguished by FT-IR/PAS. The application of the same technique to the study of a coal sample heated in air at 200°C allows the detection of different oxidation mechanisms operating inside and outside the coal. Although quantitative results are difficult to obtain, the technique can be successfully proposed for a qualitative description of coal weathering.

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Determination of the Orientation of Silanes on Silica Surfaces by Fourier Transform Infrared Photoacoustic Spectroscopy

Applied Spectroscopy ◽

10.1366/0003702864508791 ◽

1986 ◽

Vol 40 (4) ◽

pp. 513-519 ◽

Cited By ~ 25

Author(s):

Marek W. Urban ◽

Jack L. Koenig

Keyword(s):

Fourier Transform ◽

Photoacoustic Spectroscopy ◽

Surface Coverage ◽

Silica Surface ◽

Fourier Transform Infrared ◽

Coupling Agents ◽

Surface Hydroxyl ◽

Silica Surfaces ◽

Quantitative Surface Analysis ◽

Infrared Photoacoustic Spectroscopy

Fourier transform infrared photoacoustic spectroscopy has been used for quantitative surface analysis of silica treated with trifunctional coupling agents such as γ-Methacryloxypropyltriethoxysilane (γ-MPS), γ-Glycidoxypropyltrimethoxysilane (γ-GPS), and γ-Aminopropyltri-ethoxysilane (γ-APS). The calibration curves are obtained for several characteristic bands of the coupling agents. Using a highly polarizable gas in the photoacoustic cell and comparing the spectra with a nonpolarizable coupling gas, it is possible to evaluate orientation of the coupling agents on the silica surface. The type of orientation is a function of the extent of surface coverage. At low surface coverage, coupling agents tend to take a perpendicular orientation with respect to the surface, and increasing surface coverage leads to parallel orientation. Increasing the coupling agent concentration also causes orientational changes of the species which form chemical bonds with the silica surface (hydroxyl, water, and carbonyl groups).

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