Methods Development For Rapid-Scanning Gas Phase Fourier Transform Infrared/Time-Resolved (FT-IR/TRS) Spectrometry

1985 ◽  
Author(s):  
S. Penn Weaver ◽  
James A. de Haseth
Keyword(s):  
Fourier Transform ◽  
Gas Phase ◽  
Fourier Transform Infrared ◽  
Time Resolved ◽  
Methods Development ◽  
Ft Ir ◽  
Rapid Scanning

Time-Resolved Fourier Transform Infrared Spectroscopic Imaging

2003 ◽  
Vol 57 (4) ◽  
pp. 357-366 ◽  
Author(s):  
Rohit Bhargava ◽  
Ira W. Levin
Keyword(s):  
Fourier Transform ◽  
Imaging Modality ◽  
Spectroscopic Imaging ◽  
Fourier Transform Infrared ◽  
Dynamic Processes ◽  
Time Resolved ◽  
Ir Imaging ◽  
Infrared Spectroscopic ◽  
Infrared Spectroscopic Imaging ◽  
Ft Ir

Fourier transform infrared (FT-IR) imaging allows simultaneous spectral characterization of large spatial areas due to its multichannel detection advantage. The acquisition of large amounts of data in the multichannel configuration results, however, in a poor temporal resolution of sequentially acquired data sets, which limits the examination of dynamic processes to processes that have characteristic time scales of the order of minutes. Here, we introduce the concept and instrumental details of a time-resolved infrared spectroscopic imaging modality that permits the examination of repetitive dynamic processes whose half-lives are of the order of milliseconds. As an illustration of this implementation of step-scan FT-IR imaging, we examine the molecular responses to external electric-field perturbations of a microscopically heterogeneous polymer–liquid crystal composite. Analysis of the spectroscopic data using conventional univariate and generalized two-dimensional (2D) correlation methods emphasizes an additional capability for accessing of simultaneous spatial and temporal chemical measurements of molecular dynamic processes.

Instrumental Resolution Considerations for Fourier Transform Infrared Gas-Phase Spectroscopy

1997 ◽  
Vol 51 (8) ◽  
pp. 1159-1169 ◽  
Author(s):  
P. Jaakkola ◽  
J. D. Tate ◽  
M. Paakkunainen ◽  
J. Kauppinen ◽  
P. Saarinen
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Gas Phase ◽  
Dynamic Range ◽  
Fourier Transform Infrared ◽  
High Signal ◽  
Low Resolution ◽  
Instrumental Resolution ◽  
Ft Ir ◽  
Gas Phase Spectroscopy

Instrumental resolution has a significant effect on the performance of Fourier transform infrared (FT-IR) spectrometers used for gasphase analysis. Low-resolution FT-IR spectroscopy offers some valuable advantages compared with the traditional high-resolution FT-IR gas-phase spectroscopy, especially in nonlaboratory environments. First, high signal-to-noise ratio (SNR) spectra can be acquired in field conditions without the use of traditional liquid nitrogen-cooled detectors. Second, the dynamic range for quantitative analysis is larger for low-resolution spectroscopy than for high-resolution due to the lower absorbance values and lower noise levels. Third, spectral analysis speed is increased and data storage requirements are substantially reduced. The purpose of this study was to investigate the effect of instrumental resolution on FT-IR gas-phase analysis. The effects of spectral resolution on sensitivity, selectivity, accuracy, precision, spectral overlap, dynamic range, and nonlinearity are separately discussed.

Pulsed Laser Photolysis Time-Resolved FT-IR Emission Studies of Molecular Dynamics

1993 ◽  
Vol 47 (9) ◽  
pp. 1430-1437 ◽  
Author(s):  
Steven A. Rogers ◽  
Stephen R. Leone
Keyword(s):  
Fourier Transform ◽  
Time Delays ◽  
Time Synchronization ◽  
Infrared Detector ◽  
Fourier Transform Infrared ◽  
Short Delay ◽  
Time Resolved ◽  
Experimental Apparatus ◽  
Ft Ir ◽  
Ir Emission

Time-resolved Fourier transform infrared (FT-IR) emission experiments are used to study photofragmentation processes, single collision reactions, energy transfer events, and laser-initiated radical-radical reactions. In the experimental apparatus, a 200-Hz ArF excimer laser is coupled to a commercial 0.01-cm−1 resolution Fourier transform infrared spectrometer. Fringes from the He:Ne reference laser are used for time synchronization of the laser pulses to the FT-IR mirror retardation. Following a short delay after the laser pulse, the analog-to-digital converter samples the signal on the infrared detector at several time delays. A number of fringes are then skipped and the process is repeated. At the start of the next mirror sweep, data for the first time points are acquired at different mirror positions, and the process is repeated until multiple interferograms are obtained at all time delays. Through the use of improved background-limited detectors and multipass collection optics, spectra from a number of small molecules have been obtained in various processes. We report here on the comprehensive details of our experimental apparatus and discuss several of the processes studied with the use of this apparatus.

Gas-phase photodissociation of CH3COCN at 308 nm by time-resolved Fourier-transform infrared emission spectroscopy

2012 ◽  
Vol 136 (4) ◽  
pp. 044302 ◽  
Author(s):  
Yu-Ying Yeh ◽  
Meng-Hsuan Chao ◽  
Po-Yu Tsai ◽  
Yuan-Bin Chang ◽  
Ming-Tsang Tsai ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Gas Phase ◽  
Emission Spectroscopy ◽  
Fourier Transform Infrared ◽  
Infrared Emission ◽  
Time Resolved ◽  
Infrared Emission Spectroscopy

FR-IR Molecular Microanalysis System

1990 ◽  
Vol 48 (2) ◽  
pp. 270-271
Author(s):  
John A. Reffner ◽  
William T. Wihlborg
Keyword(s):  
Fourier Transform ◽  
Fourier Transform Infrared ◽  
Integrated System ◽  
Morphological Examination ◽  
Fully Integrated ◽  
Ir Microscopy ◽  
Normal Functions ◽  
Infrared Microspectroscopy ◽  
Infrared Spectral ◽  
Ft Ir

The IRμs™ is the first fully integrated system for Fourier transform infrared (FT-IR) microscopy. FT-IR microscopy combines light microscopy for morphological examination with infrared spectroscopy for chemical identification of microscopic samples or domains. Because the IRμs system is a new tool for molecular microanalysis, its optical, mechanical and system design are described to illustrate the state of development of molecular microanalysis. Applications of infrared microspectroscopy are reviewed by Messerschmidt and Harthcock.Infrared spectral analysis of microscopic samples is not a new idea, it dates back to 1949, with the first commercial instrument being offered by Perkin-Elmer Co. Inc. in 1953. These early efforts showed promise but failed the test of practically. It was not until the advances in computer science were applied did infrared microspectroscopy emerge as a useful technique. Microscopes designed as accessories for Fourier transform infrared spectrometers have been commercially available since 1983. These accessory microscopes provide the best means for analytical spectroscopists to analyze microscopic samples, while not interfering with the FT-IR spectrometer’s normal functions.

Sign in / Sign up

Export Citation Format

Share Document