FT-IR analysis

FT-IR analyses were also conducted for the original cabbage and liquidized biomass for comparison. 

Table 1 lists the main peaks detected by FT-IR analyses in the reference models C, pp, and C-pp, together with the associated functional groups. 

The authors thank D. Wymer of the Procter Gamble Company for assistance with the citrus oils SFC/FT-IR analyses, J. Freal of Adams Veterinary Research Laboratories for the pyrethrin extract, G. Adams and K. Kempfert of Nicolet Instrument Corporation for assistance with the SFC/FT-IR interface and pyrethrin extract analysis respectively. 

For reactions of NO3 with monoterpenes (a- and P-pinenes), some spectral features in the FT-IR analyses indicate carbonyl- and nitrate-containing compounds [26]. 

A variety of further tests concerning the repeatability, reproducibility and quality of IR spectra obtained can be performed. In fact, tests for these three important spectral parameters were first introduced to biomedical IR spectroscopy in the late 1980 s within the context of a project for FT-IR analyses of intact micro-organisms. In these tests, the spectral quality is checked with regard to absorbance values of the raw spectral data, the signal-to-noise ratio (SNR), spectral contributions from water vapour, optical fringes and more. Quality tests have been adapted and expanded for IR micro-spectroscopic imaging and are comprised now of five independent quality checks ... 

The vast introduction of the more sophisticated Fourier transform infrared (FT-IR) spectrometers for spectral studies made the CBS method senseless in terms of its further application. In the FT-IR analyses, the linearly polarized measurements are conducted by sequential photometrization of a sample for both positions of the polarizer. The linear dichroism is differentially registered by subtraction of the two spectra, which is implanented promptly and easily by the modem sophisticated FT-IR spectrophotometers, equipped with computerized systans. 

Determination of tire CaO exeess is earned out using ehemieal analyses whieh are time and reaetive eonsuming. Nevertheless, Fourier transform infrared (FT-IR) speetroseopie analysis of this kind of material shows a eommon vibration band at 3640 em whieh belongs to 0-H group, due to Ca(OH), generated during the neutralization reaetion. 

This is a destructive method in which the resin is ground and pelleted as a KBr disc and analysed by FT-IR analysis. This method works best for systems where disdnct ftinctional group transformations (C=0, C-OH, C=C, etc) are expected. No special equipment is needed. 

Infrared microscopy combines an optical microscope with an FT-IR spectrometer enabling pico- to femtogram (10 12—10 15 g) quantities of substances to be characterized or very small areas of larger samples to be analysed. Beam-condensing optics focus the radiation onto an area of the sample identified using the optical microscope and either reflectance or transmittance spectra can be recorded. The highly-sensitive MCT detector (p. 283) is normally used as its size can be matched to that of the radiation beam to maximize its response. 

SEM photographs were taken on a Cambridge Instruments Stereoscan 60 Machine. UV spectra were recorded using a HP 8452A spectrometer, IR spectra were recorded on a Nicolet FT-IR spectrometer and NMR spectra were taken on Bruker AM-360. Chlorine and carbon elemental analyses were used to determine the chlorine content. 

McGovern et al.26 analyzed the expression of heterologous proteins in E. coli via pyrolysis mass spectrometry and FT-IR. The application was to a2-interferon production. To analyze the data, artificial neural networks (ANN) and PLS were utilized. Because cell pastes contain more mass than the supernatant, these were used for quantitative analyses. Both the MS and IR data were difficult to interpret, but the chemometrics used allowed researchers to gain some knowledge of the process. The authors show graphics indicating the ability to follow production via either technique. 

In conclusion, the HPLC, FT-IR and H-FT-NMR analyses confirmed that the precipitate obtained via the crystallization process was vanillin. 

Aurbach and co-workers performed a series of ex situ as well as in situ spectroscopic analyses on the surface of the working electrode upon which the cyclic voltammetry of electrolytes was carried out. On the basis of the functionalities detected in FT-IR, X-ray microanalysis, and nuclear magnetic resonance (NMR) studies, they were able to investigate the mechanisms involved in the reduction process of carbonate solvents and proposed that, upon reduction, these solvents mainly form lithium alkyl carbonates (RCOsLi), which are sensitive to various contaminants in the electrolyte system. For example, the presence of CO2 or trace moisture would cause the formation of Li2COs. This peculiar reduction product has been observed on all occasions when cyclic carbonates are present, and it seems to be independent of the nature of the working electrodes. A single electron mechanism has been shown for PC reduction in Scheme 1, while those of EC and linear carbonates are shown in Scheme 7. ... 

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