Advances in handheld FT-IR instrumentation

2012 ◽  
Author(s):  
Josep Arnó ◽  
Len Cardillo ◽  
Kevin Judge ◽  
Maxim Frayer ◽  
Michael Frunzi ◽  
...  
Keyword(s):  
Ft Ir ◽  
Ir Instrumentation

Advanced sampling techniques for hand-held FT-IR instrumentation

2013 ◽  
Author(s):  
Josep Arnó ◽  
Michael Frunzi ◽  
Chris Weber ◽  
Dustin Levy
Keyword(s):  
Sampling Techniques ◽  
Advanced Sampling ◽  
Ft Ir ◽  
Ir Instrumentation

Time-Resolved Step-Scan FT-IR Spectroscopy of the Photodynamics of Carbonmonoxymyoglobin

1995 ◽  
Vol 49 (6) ◽  
pp. 702-708 ◽  
Author(s):  
Susan E. Plunkett ◽  
James L. Chao ◽  
Thomas J. Tague ◽  
Richard A. Palmer
Keyword(s):  
Ir Spectroscopy ◽  
Structural Changes ◽  
Biological Molecules ◽  
Single Frequency ◽  
Ir Absorption ◽  
Time Resolved ◽  
Ft Ir ◽  
Ir Instrumentation ◽  
Protein Response ◽  
Ft Ir Spectroscopy

The kinetics of protein response and of CO recombination after photolysis of the Fe-CO bond in carbonmonoxymyoglobin have been monitored via time-resolved step-scan FT-IR absorption difference spectroscopy in D2O solution. Although the initial photodissociation is too fast to observe with currently available FT-IR instrumentation, we have been able to correlate the CO recombination kinetics with protein secondary structural changes via changes in the amide I band of the polypeptide chain with microsecond time resolution. The spectral and kinetic data corroborate and confirm previously published single-frequency infrared studies. This is the first application of time-resolved step-scan FT-IR spectroscopy in the absorbance difference mode to study the photodynamics of an aqueous protein solution at room temperature. This work also demonstrates the potential of the technique for the sub-microsecond kinetic analysis of other biological molecules of interest.

Dynamic FT-IR. Part I: Rapid-Scan Methods in Spectroelectrochemistry

1986 ◽  
Vol 40 (2) ◽  
pp. 174-180 ◽  
Author(s):  
Stuart I. Yaniger ◽  
D. Warren Vidrine
Keyword(s):  
Signal To Noise Ratio ◽  
Electrochemical Reactions ◽  
Time Resolved ◽  
Electrochemical Processes ◽  
Rapid Scan ◽  
Medium Resolution ◽  
Reversible Reactions ◽  
Ft Ir ◽  
Ir Instrumentation ◽  
Digital Time

Current rapid-scan FT-IR instrumentation allows medium resolution (16 cm−1) infrared spectra to be acquired and separately stored at a rate of 85 spectra per second with excellent signal-to-noise ratio. This corresponds to a time resolution of about 12 ms. Higher spectral resolutions are possible at a cost of some spectrometer speed. Rapid-scan FT-IR provides a means by which the course of electrochemical reactions can be followed and, unlike digital time-resolved and double-modulation FT-IR, this method is not limited to reversible reactions and may be used with impunity by the nonspecialist. We examine several examples of irreversible electrochemical processes including solution-phase redox chemistry, electropolymerizations, and doping reactions of conducting polymers.

Generalized Implementation of Rapid-Scan Fourier Transform Infrared Spectroscopic Imaging

2002 ◽  
Vol 56 (8) ◽  
pp. 965-969 ◽  
Author(s):  
Scott W. Huffman ◽  
Rohit Bhargava ◽  
Ira W. Levin
Keyword(s):  
Fourier Transform ◽  
Data Acquisition ◽  
Spectroscopic Imaging ◽  
Fourier Transform Infrared ◽  
Imaging Data ◽  
Rapid Scan ◽  
Continuous Scanning ◽  
Ft Ir ◽  
Ir Instrumentation ◽  
Ir Spectroscopic

We describe a novel, generalized data acquisition sequence to allow rapid-scan Fourier transform infrared (FT-IR) spectroscopic imaging using focal plane array (FPA) detectors. This technique derives its applicability from the reproducible performance of modern FT-IR instrumentation and the availability of FPAs with simultaneous, full array acquisition, or snapshot electronics. Instead of sampling the entire interferogram in one mirror sweep over a predetermined retardation, as in traditional continuous-scanning techniques, the modulated light from the interferometer is recorded over several mirror sweeps. The FPA detector is synchronized for data acquisition after a specified delay with respect to the initiation of the mirror motion to provide a highly under-sampled interferogram. By incorporating appropriate delays in subsequent interferometer mirror scans, the entire interferogram is sampled and reconstructed. The signal-to-noise ratios (SNR) of the resulting interferograms are analyzed and are compared with step-scan spectroscopic imaging data.

FT-IR microspectroscopic analysis of diseased white matter brain tissues

1995 ◽  
Vol 53 ◽  
pp. 968-969
Author(s):  
Steven M. Le Vine ◽  
David L. Wetzel
Keyword(s):  
White Matter ◽  
Gray Matter ◽  
Twitcher Mouse ◽  
Grid Pattern ◽  
Marked Contrast ◽  
Spatially Resolved ◽  
Ft Ir ◽  
Ir Microspectroscopy ◽  
Chemical Evidence

In situ FT-IR microspectroscopy has allowed spatially resolved interrogation of different parts of brain tissue. In previous work the spectrrscopic features of normal barin tissue were characterized. The white matter, gray matter and basal ganglia were mapped from appropriate peak area measurements from spectra obtained in a grid pattern. Bands prevalent in white matter were mostly associated with the lipid. These included 2927 and 1469 cm-1 due to CH2 as well as carbonyl at 1740 cm-1. Also 1235 and 1085 cm-1 due to phospholipid and galactocerebroside, respectively (Figs 1and2). Localized chemical changes in the white matter as a result of white matter diseases have been studied. This involved the documentation of localized chemical evidence of demyelination in shiverer mice in which the spectra of white matter lacked the marked contrast between it and gray matter exhibited in the white matter of normal mice (Fig. 3).The twitcher mouse, a model of Krabbe’s desease, was also studied. The purpose in this case was to look for a localized build-up of psychosine in the white matter caused by deficiencies in the enzyme responsible for its breakdown under normal conditions.

Ultra-spatially resolved synchrotron powered FT-IR microspectroscopy of individual cells of biological material

1995 ◽  
Vol 53 ◽  
pp. 884-885
Author(s):  
David L. Wetzel ◽  
John A. Reffner ◽  
Gwyn P. Williams
Keyword(s):  
Thermal Noise ◽  
Spot Size ◽  
Acquisition Time ◽  
Thermal Source ◽  
Signal To Noise ◽  
Spatially Resolved ◽  
Good Spatial Resolution ◽  
Small Spot ◽  
Ft Ir ◽  
Ir Microspectroscopy

Synchrotron radiation is 100 to 1000 times brighter than a thermal source such as a globar. It is not accompanied with thermal noise and it is highly directional and nondivergent. For these reasons, it is well suited for ultra-spatially resolved FT-IR microspectroscopy. In efforts to attain good spatial resolution in FT-IR microspectroscopy with a thermal source, a considerable fraction of the infrared beam focused onto the specimen is lost when projected remote apertures are used to achieve a small spot size. This is the case because of divergence in the beam from that source. Also the brightness is limited and it is necessary to compromise on the signal-to-noise or to expect a long acquisition time from coadding many scans. A synchrotron powered FT-IR Microspectrometer does not suffer from this effect. Since most of the unaperatured beam’s energy makes it through even a 12 × 12 μm aperture, that is a starting place for aperture dimension reduction.

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.

Polarized microbeam FT-IR analysis of single fibers

1996 ◽  
Vol 54 ◽  
pp. 206-207
Author(s):  
Liling Cho ◽  
David L. Wetzel
Keyword(s):  
Molecular Orientation ◽  
Transition Point ◽  
Polymer Fibers ◽  
Single Fiber ◽  
Wire Grid ◽  
Polyester Fibers ◽  
Ft Ir ◽  
Ir Analysis ◽  
The Relationship ◽  
Wire Grid Polarizer

Polarized infrared microscopy has been used for forensic purposes to differentiate among polymer fibers. Dichroism can be used to compare and discriminate between different polyester fibers, including those composed of polyethylene terephthalate that are frequently encountered during criminal casework. In the fiber manufacturering process, fibers are drawn to develop molecular orientation and crystallinity. Macromolecular chains are oriented with respect to the long axis of the fiber. It is desirable to determine the relationship between the molecular orientation and stretching properties. This is particularly useful on a single fiber basis. Polarized spectroscopic differences observed from a single fiber are proposed to reveal the extent of molecular orientation within that single fiber. In the work presented, we compared the dichroic ratio between unstretched and stretched polyester fibers, and the transition point between the two forms of the same fiber. These techniques were applied to different polyester fibers. A fiber stretching device was fabricated for use on the instrument (IRμs, Spectra-Tech) stage. Tension was applied with a micrometer screw until a “neck” was produced in the stretched fiber. Spectra were obtained from an area of 24×48 μm. A wire-grid polarizer was used between the source and the sample.

Pemanfaatan Cangkang Pensi (Corbicula Moltkiana) sebagai Bahan Penyerap Zat Warna Rhodamin B Dalam Larutan

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Rahmiana Zein ◽  
Mutia Khuratul Aini ◽  
Hermansyah Aziz
Keyword(s):  
Rhodamine B ◽  
Sem Analysis ◽  
Spectra Analysis ◽  
Biosorption Capacity ◽  
Biosorption Process ◽  
Langmuir Isotherm Model ◽  
Ft Ir ◽  
Cationic Exchange ◽  
Rhodamin B ◽  
Model Isotherm

Biosorpsi zat warna Rhodamine B menggunakan cangkang Pensi (Corbicula moltkiana) telah dikaji. Percobaan dilakukan dengan system batch guna memperoleh kondisi optimum biosorspi zat warna. Kapasitas biosorpsi zat warna pada pH 2 adalah 0.9958 mg/g, dengan konsentrasi larutan mula-mula 150 mg/L waktu kontak 105 menit, massa biosorben 0.1 g, ukuran partikel 32 µm dan temperature pengeringan biosorben pada 75oC. Model isotherm Langmuir menunjukkan bahwa proses penyerapan berlangsung secara kimia dan biosorpsi homogeny dari adsorbat (Rhodamine B) pada permukaan biosorben membentuk lapisan tunggal dengan nilai R2 0.9966. Analisis XRF menunjukkan bahwa penurunan kadar unsur logam pada cangkang Pensi membuktikan bahwa proses biosorpsi berlangsung dengan pertukaran kation. Hasil analisis spektrum FT-IR membuktikan adanya interaksi antaramolekul Rhodamin B dengan gugus fungsi pada cangkang Pensi. Analisis dengan SEM memperlihatkan bahwa pori-pori cangkang Pensi telah terisi penuh oleh molekul Rhodamin B. Kondisi optimum biosorpsi telah diaplikasikan pada limbah kerupuk merah dengan kapasitas penyerapan sebesar 0,2835 mg/g.   The biosorption of Rhodamine B dyes by Pensi (Corbicula moltkiana) shell has been investigated. The experiment was conducted in batch sistem in order to obtain the optimum conditions of dye biosorption. Biosorption capacity of dye was 0.9958 mg/g at pH 2, initial concentration 150 mg/L, contact time 105 minutes, biosorbent mass 0.1 gram, particle size 32 µ m and biosorbent drying temperature was at 75oC. The Langmuir Isotherm model showed chemisorption and homogeneous biosorption process of adsorbates onto the biosorbent surface formed monolayer dye molecules on the biosorbent surface with R2 value was 0.9966. XRF analysis showed that reduction of metals unsure quantity of pensi shell indicated biosorption process was occupied through cationic exchange. The result of FTIR spectra analysis indicated an interaction between Rhodamin B molecules and functional group of pensi shell. SEM analysis showed that the pensi shell pores were completely filled by Rhodamine B molecules. The optimum condition of biosorption has been aplicated in red chips wastewater industry with biosorption capacity was 0.2835 mg/g.

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