Infrared Spectroscopy internal reflectance

Pattacini, S. Solving Analytical Problems Using Infrared Spectroscopy Internal Reflectance Sampling Techniques, Pattacini Associates, LLC Danbury, CT. 

Mossoba, M.M., Adam, M., and Lee, T. 2001b. Rapid determination of total trans fat content. An attenuated total reflection infrared spectroscopy international collaborative study. AOAC International 84 1144-1150. 

IRE Infrared emission spectroscopy, internal reflection element... 

ATR has been found as an easy to use, non-destmctive and surface-sensitive IR sampling technique for the in situ investigation of CMP processes (Hind et al., 2001). It was initially pushed by Harrick (1967) and comprehensively treated in his early book and following editions together with Mirabella (1985). Numerous alternative and partially deceptive names are used instead of ATR spectroscopy internal reflection spectroscopy, evanescent wave spectroscopy, frustrated total internal reflection (FTIR, which should not to be confused with Fourier-transform infrared spectroscopy) and multiple internal reflection (MIR, which should not to be confused with mid-infrared )- Therefore, in the following the term ATR as defined in Section 14.4.1 and illustrated with Figure 14.8 is used exclusively. 

Spectroscopic Methods UV-VIS Spectroscopy Fourier Transform Infrared FITR Internal Reflection ATR External Reflection RA Emission Spectroscopy Difiuse Reflectance DRIFT Infrared Microscopy Photoacoustic Spectroscopy PA Rheo-Photoacoustic Spect. RPA Ellipsometiy... 

Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy. Attenuated total redectance (atr) ftir spectroscopy is based on the principle of total internal redection (40). Methods based on internal redection in the uv and visible regions of the spectmm are also common in addition to those in the ir region. The implementation of internal redection in the ir region of the spectmm provides a means of obtaining ir spectra of surfaces or interfaces, thus providing moleculady-specific vibrational information. 

Langmuir-Blodged films have been deposited on many different substrates. The substrates used include different types of glass (such as quartz for UV-visible spectroscopy) CaF2 plates for transmission infrared spectroscopy silicon, germanium, and ZnSe plates for internal reflection infrared spectroscopy. For electrochemical applications, LB films... 

Figure 7. Total internal reflection sum frequency generation (TIR-SFG) vibrational spectroscopy of high-pressure room temperature adsorption of carbon monoxide on PVP-protected Pt cube monolayers and calcined (373 K, 3h) monolayers [27], The infrared spectra demonstrate CO is adsorbed at atop sites, but is considerably red-shifted on the PVP-protected Pt cubes. After calcination, the atop frequency blueshifts to 2085 cm in good agreement with CO adsorption on Pt(l 0 0) at high coverages [28], (Reprinted from Ref [27], 2006, with permission from American Chemical Society.)...

In materials investigations surface-sensitive techniques are of special interest. The major contribution of infrared spectroscopy to this field is internal reflection spectroscopy (IRS), often called the "attenuated total reflection" (ATR) technique. To describe theory and principle, electromagnetic wave theory must be apphed [33]. 

We wondered why NSCs proliferated exclusively on surfaces with EGF-His ligands anchored by coordination. We focused on two aspects in particular the conformational integrity of coordinated EGF-His and the stability of coordinate bonds at the interface. Conformational information was acquired with multiple internal reflection-infrared absorption spectroscopy (MIR-IRAS) [97]. The stability of coordinate bonds was assessed by culturing NSCs on a surface with a small region of EGF-His ligands anchored by coordination. This spatially restricted EGF-His anchoring enabled an intuitive exploration of EGF-His release under cell culture conditions. 

Characterization of Anion Binding on Goethite Using Titration Calorimetry and Cylindrical Internal Reflection-Fourier Transform Infrared Spectroscopy... 

Titration calorimetry and cylindrical internal reflection-Fourier transform infrared (CIR-FTIR) spectroscopy are two techniques which have seldom been applied to study reactions at the solid-liquid interface. In this paper, we describe these two techniques and their application to the investigation of salicylate ion adsorption in aqueous goethite (a-FeOOH) suspensions from pH 4 to 7. Evidence suggests that salicylate adsorbs on goethite by forming a chelate structure in which each salicylate ion replaces two hydroxyls attached to a single iron atom at the surface. 

To put things into perspective, we. can broadly classify these analytical methods into bulk, dry surface, and in situ interfacial techniques. This chapter focuses on the last category, illustrating two in situ techniques used to study anion binding at the goethite (a-FeOOH)-water interface titration calorimetry and cylindrical internal reflection-Fourier transform infrared (CIR-FTIR) spectroscopy. In fact, CIR-FTIR could prove to be extremely powerful, since it allows direct spectroscopic observation of ions adsorbed at the mineral-water interface. 

Cylindrical. Internal Reflection - Fourier Transform Infrared (CIR-FTIR) Spectroscopy... 

Schulten, H.-R., and Soldati, F. (1981). Identification of ginsenosides from Panax ginseng in fractions obtained by high-performance liquid chromatography by field desorption mass spectrometry, multiple internal reflection infrared spectroscopy and thin layer chromatography. J. Chromatogr. 212, 37-i9. 

The analysis of pharmaceutical agents in preparations has been one of the most important applications of modem RPC. A simple gradient maker to be used on the low pressure side of the pump for use in gradient elution of pharmaceuticals has been described (560). For the detection and identification of pharmaceuticals, micro internal reflection infrared spectroscopy (561) and ultraviolet scanning spectroscopy with stopped flow (562) were also employed. 

An infrared spectrum is a plot of percent radiation absorbed versus the frequency of the incident radiation given in wavenumbers (cm ) or in wave length ( xm). A variation of this method, diffuse reflectance spectroscopy, is used for samples with poor transmittance, e.g. cubic hematite crystals. Increased resolution and sensitivity as well as more rapid collection of data is provided by Fourier-transform-IR (FTIR), which averages a large number of spectra. Another IR technique makes use of attenuated total reflectance FTIR (ATR-FTIR) often using a cylindrical internal reflectance cell (CIR) (e.g. Tejedor-Tejedor Anderson, 1986). ATR enables wet systems and adsorbing species to be studied in situ. 

Tejedor-Tejedor, M.L Yost, E.C. Anderson, M.C. (1990a) Characterization of benzoic acid and phenolic complexes at the goethite/ aqueous solution interface using cylindrical internal reflectance Fourier transform infrared spectroscopy. Part 5 Methodology. Langmuir 6 979-987... 

All of the usual sampling techniques used in infrared spectroscopy can be used with FT-IR instrumentation. The optics of the sampling chamber of commercial FT-IR instruments are the same as the traditional dispersive instruments so the accessories can be used without modification for the most part. To make full use of the larger aperature of the FT-IR instrument, some accessories should be modified to accomodate the larger beam. The instrumental advantages of FT-IR allow one to use a number of sampling techniques which are not effective using dispersive instrumentation. Transmission, diffuse reflectance and internal reflectance techniques are most often used in the study of epoxy resins. 

Mechanical deformation induces orientation into the polymer samples and polarized infrared can be used to characterize this orientation either by direct measurement of the dichroic ratio 287,289) or by spectral subtraction 286), three dimensional sample tilting 68,286), or internal reflection spectroscopy 130). 

Infrared spectroscopy. IR spectra were recorded on a Nicolet 5DX FT-IR spectrometer. A thin coating of the condensed silanes was applied on KBr pellets made from a very high purity KBr powder (J. T. Baker Chemical Co.). The spectra of these pellets were recorded using the transmission method. Liquid silanes were analyzed using the internal reflection attachment (IRA). The number of scans was chosen to be 20 for both background and samples. 

ASTM E-334. Standard Practice for General Techniques of Infrared Microanalysis. ASTM E-573. Standard Practices for Internal Reflection Spectroscopy. 

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