Attenuated total reflectance fourier transform infrared spectrometry

DETERMINATION OF NUTRITIONAL PARAMETERS OF YOGHURT SAMPLES THROUGH PARTIAL-LEAST-SQUARES ATTENUATED TOTAL REFLECTANCE FOURIER TRANSFORM INFRARED SPECTROMETRY... 

An example of blending was when phenylcarbomylated or azido phenylcarbo-mylated p-CD was successfully blended with polymethyl methacrylate (PMMA) and electrospun into nanofibrous membranes for organic waste treatment and water purification (Kaur et al. 2006). The presence of the p-CD derivatives on the surface of the nanofibers was confirmed by attenuated total reflectance-Fourier transform infrared spectrometry (ATR-FTIR) and x-ray photoelectron spectroscopy (XPS). A solution containing phenolphthalein (PHP) was used to determine the ability of the functionalized membranes to capture small organic molecules. The results showed... 

The aim of this work is the determination of several nutritional parameters, such as Energetic Value, Protein, Fat, and Carbohydrates content, in commercially available yoghurt samples by using Attenuated Total Reflectance Fourier Transform Infrared (ATR-FT-IR) spectrometry and a partial least square approach. 

To shed light on the mechanism of formation of silsesquioxane a7b3, to identify the species formed during the process, and to try to explain the high selectivity towards structure a7b3 of the optimised synthetic method described above (64% yield in 18 h), the synthesis of cyclopentyl silsesquioxane a7b3 was monitored by electrospray ionisation mass spectrometry (ESI MS) [50-52] and in situ attenuated total reflection Fourier-transform infrared (ATR FTIR) spectroscopy [53, 54]. Spectroscopic data from the latter were analysed using chemometric methods to identify the pure component spectra and relative concentration profiles. 

Spectroscopic methods are mainly useful to identify the elements, functional groups, and chemical structures close to the biomaterial surface. Techniques like X-ray photoelectron spectroscopy, attenuated total reflection fourier transform infrared spectroscopy, and secondary ion mass spectrometry have been used widely in determining the elemental composition and charged species at biomaterial surface. Other important characteristics obtained from the biomaterial surface are surface energy and relative wettability using thermodynamic method such as contact angle experiments. 

Among these, some of the most frequently used are attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. X-ray photoelectron spectroscopy (XPS), static secondary ion mass spectrometry (SSIMS), energy dispersive X-ray spectroscopy (EDS), optical microscopy, laser confocal scanning microscopy (LCSM), scanning electron microscopy (SEM), enviromnental scanning electron microscopy (ESEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), contact angle measurement, and some evaluation methods for the biocompatibility of membrane surfaces. 

Umezawa, K. Lin, X.M. Nishizawa. S. Sugawara, M. Umezawa, Y. Cation permselectivity in the phase boundary of ionophore-incorporated solvent polymeric membranes as studied by fourier transform infrared attenuated total reflection spectrometry. Anal. Chim. Acta 1993. 282. 247-257. 

Surface characterization by spectroscopic techniques yields information on the functional groups and elemental composition on the surface of polymeric biomaterials. The most common spectroscopic tools used for biomedical polymers are X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), secondary ion mass spectrometry (SIMS), and Fourier transform infrared spectroscopy (FTIR) (diffuse reflectance and attenuated total internal reflectance modes). Each of these techniques is discussed in the succeeding text. 

Hsu and Marshall identified dyes in solid poly(methylmethylacrylate) by laser desorption Fourier Transform Ion Cyclotron Resonance Mass Spectrometry. Accurate mass measurements identified several red and orange dyes in untreated poly(methmethacrylate) at an order of magnitude lower (0.1%) than obtained by infrared attenuated total reflectance spectroscopy (1 - 2%). 

Attenuated total reflection (ATR) has grown into the most widely practiced technique in infrared spectrometry. The reasons for this are fairly straightforward the technique requires little or no sample preparation, and consistent results can be obtained with relatively little care or expertise. The technique is not foolproof, but it can be very forgiving. ATR spectrometry is known by a number of alternative names, for example, multiple internal reflection (MIR), which is not to be confused with mid-infrared, frustrated multiple internal reflection (FMIR), evanescent wave spectrometry (EWS), frustrated total internal reflection (FTIR), which is not the same as Fourier transform infrared (FT-IR) spectrometry, and internal reflection spectrometry (IRS), but IRS is better known, at least in the United States, as the Internal Revenue Service. 

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