Diffuse-reflectance infrared spectroscopy

Infrared Spectroscopy Transmission Infrared Spectroscopy Diffuse Reflectance Infrared Spectroscopy (DRS, DRIFT) Infrared Emission Spectroscopy (IRES)... [Pg.216]

Infrared spectroscopy Transmission infrared spectroscopy Diffuse reflectance infrared spectroscopy (DRIFTS) Attenuated total reflection (ATR)... [Pg.217]

Infrared spectroscopy Diffuse reflectance analysis eliminates the mechanical stress of preparing a KBr pellet, and may permit identification of more fragile crystal forms.47... [Pg.237]

DRIFTS infrared spectroscopy Diffuse-reflectance infrared No Yes> .209... [Pg.159]

Fourier transform spectroscopy diffuse reflectance infrared, 24 72, 110-111... [Pg.379]

Infrared microscopy, diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, and photoacoustic spectroscopy (PAS) techniques may be suitable for some types of sample but the use of... [Pg.362]

Spectroscopy. - In the following paragraphs we discuss how various spectroscopy tools have been used to illuminate the rich surface chemistry of supported polynuclear metal complexes. These methods include infrared (both diffuse reflectance and transmission), ultraviolet and visible (UV-Vis), x-ray photoelectron spectroscopy (XPS), and x-ray absorption, near edge spectroscopy s (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopy s. [Pg.97]

Ritchie, G. E., Gehrlein, L., and Ciurczak, E. W. Simultaneous development, validation and implementation of a near-infrared (NIR) diffuse reflectance spectroscopic identification method for pharmaceutically active and inactive (placebo) clinical dosage forms. In Pittsburgh Conference of Analytical Chemistry and Applied Spectroscopy, March 2000, New Orleans, LA. [Pg.265]

Mesoporous vanadosilicate molecular sieves with MCM-48 structure and atomic SiA ratio 30-200 have been synthesized using vanadyl sulphate as the source of vanadium. The product was characterized using X-ray diffraction (XRD), Nj adsorption analysis, transmision electron microscopy (TEM), electron spin resonance (ESR), Fourier-transform Infrared (FTIR), Diffuse reflectance UV-visible spectroscopy (UV-vis) and V solid state NMR. A noticeable decrease in unit cell parameters and main pore diameter was observed. Thus, a strong interaction between vanadium and mesoporous wall can be suggested. [Pg.249]

In the MIR, diffuse reflectance is very weak and could only be measured after routine FT-IR spectrometers became available (DRIFT spectroscopy, diffuse reflectance infrared Fourier-transform spectroscopy). Due to the lack of ideal non-absorbing scattering substrates in the MIR, the diffusely reflected MIR radiation is generally collected by large ellipsoidal mirrors, which cover as much area above the sample as possible. Two optical configurations are commercially available, on-axis and off-axis designs (Fig. 5.9). [Pg.80]

Spectroscopy detection of components through the measurement of their wavelengths in characteristic bands. The most frequently used instruments are infrared, ultraviolet, diffuse reflectance, etc. These properties are proportional to the concentrations of the components and may be related to their respective conversion factors. [Pg.4]

There are many techniques [26] for characterization of HPOPs. Spectroscopic methods such as infrared spectroscopy, visible spectroscopy, diffuse reflectance spectroscopy, mass spectrometry (MS), atomic absorption (AA), inductively coupled plasma (ICP), X-ray fluorescence (XRF), X-ray diffraction (XRD), nuclear magnetic resonance (NMR), electron spectroscopy for chemical analysis (ESCA),... [Pg.358]

Emission Spectroscopy Diffuse Reflectance DRIFT Infrared Microscopy Photoacoustic Spectroscopy PA Rheo-Photoacoustic Spectroscopy Ellipsometiy... [Pg.4]

Near-infrared (NIR) spectra are rarely used to identify materials, but NIR spectroscopy has nonetheless assumed a role of great importance for contemporary analytical chemists. Near-infrared (NIR) diffuse reflection spectroscopy became of great importance in the 1970s, when it was shown that the concentration of protein, oil, and water... [Pg.358]

ESC] X-ray diffiaction, Fourie-transform infrared and diffuse reflectance ultraviolet-visible spectroscopy 400-900°C/Fe203-Al203... [Pg.143]

Vibrational Spectroscopy. Infrared absorption spectra may be obtained using convention IR or FTIR instrumentation the catalyst may be present as a compressed disk, allowing transmission spectroscopy. If the surface area is high, there can be enough chemisorbed species for their spectra to be recorded. This approach is widely used to follow actual catalyzed reactions see, for example. Refs. 26 (metal oxide catalysts) and 27 (zeolitic catalysts). Diffuse reflectance infrared reflection spectroscopy (DRIFT S) may be used on films [e.g.. Ref. 28—Si02 films on Mo(llO)]. Laser Raman spectroscopy (e.g.. Refs. 29, 30) and infrared emission spectroscopy may give greater detail [31]. [Pg.689]

Vreugdenhil A J and Butler I S 1998 Investigation of MMT adsorption on soils by diffuse reflectance infrared spectroscopy DRIFTS and headspace analysis gas-phase infrared spectroscopy HAGIS Appl. Organomet. Chem. [Pg.1795]

Diffuse reflectance infrared Fourier transform spectroscopy... [Pg.313]

Several properties of the filler are important to the compounder (279). Properties that are frequentiy reported by fumed sihca manufacturers include the acidity of the filler, nitrogen adsorption, oil absorption, and particle size distribution (280,281). The adsorption techniques provide a measure of the surface area of the filler, whereas oil absorption is an indication of the stmcture of the filler (282). Measurement of the sdanol concentration is critical, and some techniques that are commonly used in the industry to estimate this parameter are the methyl red absorption and methanol wettabihty (273,274,277) tests. Other techniques include various spectroscopies, such as diffuse reflectance infrared spectroscopy (drift), inverse gas chromatography (igc), photoacoustic ir, nmr, Raman, and surface forces apparatus (277,283—290). [Pg.49]

Transmission infrared spectroscopy is very popular for studying the adsorption of gases on supported catalysts and for studying the decomposition of infrared active catalyst precursors during catalyst preparation. Infrared spectroscopy is an in situ technique that is applicable in transmission or diffuse reflection mode on real catalysts. [Pg.158]

Diffuse reflectance infrared Fourier transform spectroscopy deuterium triglycine sulphate energy compensated atom probe energy dispersive analysis energy-loss near edge structure electron probe X-ray microanalysis elastic recoil detection analysis (see also FreS) electron spectroscopy for chemical analysis extended energy-loss fine structure field emission gun focused ion beam field ion microscope... [Pg.226]

The most important methods used in in-situ studies of electrode surfaces are various modifications of reflection spectroscopy in the ultraviolet through infrared regions. For electrochemical applications, the specular reflection (at smooth electrode surfaces) is much more important than the diffuse reflection from matt surfaces. The reflectivity, R, of the electrode/ electrolyte interface is defined by ... [Pg.342]

Although acetone was a major product, it was not observed by infrared spectroscopy. Flowing helium/acetone over the catalyst at room temperature gave a prominent carbonyl band at 1723 cm 1 (not show here). In this study, a DRIFTS (diffuse reflectance infrared Fourier transform spectroscopy) cell was placed in front of a fixed reactor DRIFTS only monitored the adsorbed and gaseous species in the front end of the catalyst bed. The absence of acetone s carbonyl IR band in Figure 3 and its presence in the reactor effluent suggest the following possibilities (i) acetone formation from partial oxidation is slower than epoxidation to form PO and/or (ii) acetone is produced from a secondary reaction of PO. [Pg.407]

The experimental system consists of three sections (i) a gas metering section with interconnected 4-port and 6-port valves, (ii) a reactor section including an in-situ diffused reflectance infrared Fourier transform spectroscopy reactor (DRIFTS) connected to tubular quartz reactor, (iii) an effluent gas analysis section including a mass spectrometer or a gas chromatograph (9). [Pg.410]

Intensified metabolic control, especially in case of diabetes, demands minimal-invasive or non-invasive methods of analytical measurement. For this goal, a method has been developed to measure the blood glucose content in vivo, in direct contact with the skin, by means of diffuse reflection near infrared (NIR) spectroscopy on the basis of multivariate calibration and neural networks (Muller et al. [1997] Fischbacher et al. [1997] Danzer et al. [1998]). Because no patients with any standard blood glucose value are available in principle, a method of indirect calibration has... [Pg.175]

Danzer K, Fischbacher C, Jagemann K-U, Reichelt KJ (1998) Near-infrared diffuse reflection spectroscopy for non-invasive blood-glucose monitoring. LEOS Newslett 12(2) 9... [Pg.198]

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