Atmospheric Compensation in Fourier Transform Infrared (FT-IR) Spectra of Clinical Samples

2013 ◽  
Vol 67 (11) ◽  
pp. 1339-1342 ◽  
Author(s):  
David Perez-Guaita ◽  
Julia Kuligowski ◽  
Guillermo Quintás ◽  
Salvador Garrigues ◽  
Miguel de la Guardia
Keyword(s):  
Fourier Transform ◽  
Ir Spectra ◽  
Fourier Transform Infrared ◽  
Clinical Samples ◽  
Atmospheric Compensation ◽  
Ft Ir

scholarly journals Application of Fourier Transform Infrared Spectroscopy and Chemometrics for Differentiation of Salmonella enterica Serovar Enteritidis Phage Types

2010 ◽  
Vol 76 (11) ◽  
pp. 3538-3544 ◽  
Author(s):  
Ornella Preisner ◽  
Raquel Guiomar ◽  
Jorge Machado ◽  
Jos� Cardoso Menezes ◽  
Jo�o Almeida Lopes
Keyword(s):  
Fourier Transform ◽  
Ir Spectra ◽  
Salmonella Enterica ◽  
Intact Cell ◽  
Phage Type ◽  
Fourier Transform Infrared ◽  
Intact Cells ◽  
Phage Types ◽  
Ft Ir ◽  
Ir Analysis

ABSTRACT Fourier transform infrared (FT-IR) spectroscopy and chemometric techniques were used to discriminate five closely related Salmonella enterica serotype Enteritidis phage types, phage type 1 (PT1), PT1b, PT4b, PT6, and PT6a. Intact cells and outer membrane protein (OMP) extracts from bacterial cell membranes were subjected to FT-IR analysis in transmittance mode. Spectra were collected over a wavenumber range from 4,000 to 600 cm−1. Partial least-squares discriminant analysis (PLS-DA) was used to develop calibration models based on preprocessed FT-IR spectra. The analysis based on OMP extracts provided greater separation between the Salmonella Enteritidis PT1-PT1b, PT4b, and PT6-PT6a groups than the intact cell analysis. When these three phage type groups were considered, the method based on OMP extract FT-IR spectra was 100% accurate. Moreover, complementary local models that considered only the PT1-PT1b and PT6-PT6a groups were developed, and the level of discrimination increased. PT1 and PT1b isolates were differentiated successfully with the local model using the entire OMP extract spectrum (98.3% correct predictions), whereas the accuracy of discrimination between PT6 and PT6a isolates was 86.0%. Isolates belonging to different phage types (PT19, PT20, and PT21) were used with the model to test its robustness. For the first time it was demonstrated that FT-IR analysis of OMP extracts can be used for construction of robust models that allow fast and accurate discrimination of different Salmonella Enteritidis phage types.

Application of Fourier Transform Infrared Spectroscopy in Quantitation of Trierucin in High-Erucic-Acid Rapeseed Oils

1998 ◽  
Vol 52 (7) ◽  
pp. 990-993 ◽  
Author(s):  
M. Khalique Ahmed ◽  
Jim Daun ◽  
Doug Declercq
Keyword(s):  
Fourier Transform ◽  
Ir Spectra ◽  
Erucic Acid ◽  
Ir Spectrum ◽  
Fourier Transform Infrared ◽  
Brassica Napus L ◽  
Crambe Abyssinica ◽  
High Erucic Acid ◽  
Ft Ir ◽  
Hear Oil

Development of varieties of high-erucic-acid (HEAR) rapeseed with high levels of erucic acid (C22:1) would be valuable for use in oleochemical feedstocks. As an aid to this breeding effort, a rapid method to detect trierucin (C22:1 triacylglycerol), an indicator that erucic acid is being incorporated in all three positions of the triacylglycerol, would be useful. Fingerprint (1850–600 cm−1) Fourier transform infrared (FT-IR) spectra of HEAR oil extracted from Brassica napus L. cv. Mercury, trierucin, and varying amounts of trierucin spiked in this oil were recorded. The regions of 1790–1690 cm−1 and 1485–990 cm−1 were subjected to a partial least-squares (PLS) procedure to obtain a calibration equation [ R2 = 0.992 and root-mean-squared deviation (RMSD) = 2.78]. The established calibration was then tested on the spectra of mixtures of another HEAR oil from B. napus cv. Turret and trierucin. The predicted values differ from the actual values with an RMSD of 1.6%. The calibration was also tested on high-erucic-acid oils from crambe ( Crambe abyssinica) and nasturtium ( Tropaeolum majus L.) seeds. For crambe, the value found (0.4%) was close to that reported in the literature, while the value of 75% for nasturtium oil was close to the value for total triacylglycerols with erucic acid in the 2-position as reported in the literature. FT-IR spectra of triolein (C18: 1 triacylglycerol), trieicosenoin (C20:1 triacylglycerol), and trinervonin (C24:1 triacylglycerol) compared with the FT-IR spectrum of trierucin revealed the uniqueness of IR spectrum of trierucin that forms the basis of PLS analysis of trierucin in HEAR oils.

Protein hydration in living cells probed by Fourier transform infrared (FT-IR) spectroscopic imaging

The Analyst ◽  
2017 ◽  
Vol 142 (13) ◽  
pp. 2475-2483 ◽  
Author(s):  
H. Shinzawa ◽  
B. Turner ◽  
J. Mizukado ◽  
S. G. Kazarian
Keyword(s):  
Fourier Transform ◽  
Ir Spectra ◽  
Spectroscopic Imaging ◽  
Fourier Transform Infrared ◽  
Living Cells ◽  
Protein Hydration ◽  
Ft Ir ◽  
Ir Spectroscopic

FT-IR spectra of a HEK cell were analyzed with 2D disrelation mapping to reveal molecular states of water and protein hydration.

Detection and quantification of food colorant adulteration in saffron sample using chemometric analysis of FT-IR spectra

RSC Advances ◽  
2016 ◽  
Vol 6 (27) ◽  
pp. 23085-23093 ◽  
Author(s):  
Sadegh Karimi ◽  
Javad Feizy ◽  
Fatemeh Mehrjo ◽  
Maryam Farrokhnia
Keyword(s):  
Pattern Recognition ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Ir Spectra ◽  
Fourier Transform Infrared Spectroscopy ◽  
Fourier Transform Infrared ◽  
Chemometric Analysis ◽  
Food Colorants ◽  
Ft Ir ◽  
Detection And Quantification

The aim of present study is to investigate the combination of Fourier transform infrared spectroscopy with pattern recognition to recognize the standard saffron from those which have been adulterated with various types of food colorants.

scholarly journals Plasma Protein Contents Determined by Fourier-Transform Infrared Spectrometry

2001 ◽  
Vol 47 (4) ◽  
pp. 730-738 ◽  
Author(s):  
Cyril Petibois ◽  
Georges Cazorla ◽  
André Cassaigne ◽  
Gérard Déléris
Keyword(s):  
Fourier Transform ◽  
Ir Spectra ◽  
Spectral Range ◽  
Plasma Proteins ◽  
Fourier Transform Infrared ◽  
Infrared Spectrometry ◽  
Ir Absorption ◽  
Apo B ◽  
Ir Spectrometry ◽  
Ft Ir

Abstract Background: Fourier-transform infrared (FT-IR) spectrometry has been used to measure small molecules in plasma. We wished to extend this use to measurement of plasma proteins. Methods: We analyzed plasma proteins, glucose, lactate, and urea in 49 blood samples from 35 healthy subjects and 14 patients. For determining the concentration of each biomolecule, the method used the following steps: (a) The biomolecule was sought for which the correlation between spectral range areas of plasma FT-IR spectra and concentrations determined by comparison method was greatest. (b) The IR absorption of the biomolecule at the most characteristic spectral range was calculated by analyzing pure samples of known concentrations. (c) The plasma concentration of the biomolecule was determined using the FT-IR absorption of the pure compound and the integration value obtained for the plasma FT-IR spectra. (d) The spectral contribution of the biomolecule was subtracted from the plasma FT-IR spectra, and the resulting spectra were saved for further analyses. (e) The same method was then applied to determining the concentrations of other biomolecules by sequentially comparing the resulting FT-IR spectra. Results: Results agreed with those obtained by clinical methods for the following biomolecules when analyzed in the following order: albumin, glucose, fibrinogen, IgG2, lactate, IgG1, α1-antitrypsin, α2-macroglobulin, transferrin, apolipoprotein (Apo)-A1, urea, Apo-B, IgM, Apo-C3, IgA, IgG4, IgG3, IgD, haptoglobin, and α1-acid glycoprotein. Conclusion: FT-IR spectrometry is a useful tool for determining concentrations of several plasma biomolecules.

Detection Limits for Blood on Fabrics Using Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) Spectroscopy and Derivative Processing

2016 ◽  
Vol 71 (5) ◽  
pp. 839-846 ◽  
Author(s):  
Zhenyu Lu ◽  
Stephanie A. DeJong ◽  
Brianna M. Cassidy ◽  
Raymond G. Belliveau ◽  
Michael L. Myrick ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Ir Spectra ◽  
Front Surface ◽  
Fourier Transform Infrared ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Least Squares Regression ◽  
Blood Concentrations ◽  
Ft Ir ◽  
Preprocessing Technique

Attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR) was used to detect blood stains based on signature protein absorption in the mid-IR region, where intensity changes in the spectrum can be related to blood concentration. Partial least squares regression (PLSR) was applied for multivariate calibrations of IR spectra of blood dilutions on four types of fabric (acrylic, nylon, polyester, and cotton). Gap derivatives (GDs) were applied as a preprocessing technique to optimize the performance of calibration models. We report a much improved IR detection limit (DL) for blood on cotton (2700× in dilution factor units) and the first IR DL reported for blood on nylon (250×). Due to sample heterogeneity caused by fabric hydrophobicity, acrylic fabric produced variable ATR FT-IR spectra that caused poor DLs in concentration units compared to previous work. Polyester showed a similar problem at low blood concentrations that lead to a relatively poor DL as well. However, the increased surface sensitivity and decreased penetration depth of ATR FT-IR make it an excellent choice for detection of small quantities of blood on the front surface of all fabrics tested (0.0010 µg for cotton, 0.0077 µg for nylon, 0.011 µg for acrylic, and 0.0066 µg for polyester).

Quantitative Fourier Transform Infrared Diagnostics of the Gas-Phase Composition Using the HITRAN Database and the Equivalent Width of the Spectral Features

2009 ◽  
Vol 63 (11) ◽  
pp. 1211-1222 ◽  
Author(s):  
A. V. Sepman ◽  
R. den Blanken ◽  
R. Schepers ◽  
L. P. H. de Goey
Keyword(s):  
Thermal Decomposition ◽  
Fourier Transform ◽  
Ir Spectra ◽  
Equivalent Width ◽  
Fourier Transform Infrared ◽  
Molecular Spectra ◽  
Spectral Features ◽  
Hitran Database ◽  
Sample Cell ◽  
Ft Ir

This paper presents a strategy for quantification of medium resolution Fourier transform infrared (FT-IR) spectra. The approach is based on a comparison of the values of the equivalent width of spectral features determined from the measured FT-IR spectra with those calculated from corresponding molecular spectra simulated using spectroscopic parameters tabulated in the HITRAN database. Although the equivalent-width method is routinely applied in many high-resolution experiments, its potential is often ignored when the spectral resolution of the measurements is bigger than the width of the studied molecular transitions. Here with an eye on application of the method to the study of the biomass thermal decomposition products, we demonstrate the capability of the method for analysis of FT-IR spectra with moderate resolution. The method is validated for a number of molecules (NH3, CO, CH4, C2H2, C2H4, and NO) that are important products of biomass thermal decomposition. Namely, known amounts of gases were placed in a sample cell and their concentrations were determined using the method for different FT-IR settings. The agreement between the concentration values determined using the present method and those found in the sample cell was generally better than 10%. The paper also shows examples of application of the developed methodology for the analysis of FT-IR spectra from biomass pyrolysis.

scholarly journals Fourier transform infrared (FT‐IR) spectra characterization of recycled carbon fiber composites: Mini review

2019 ◽  
Author(s):  
Seyed Hossein Mamanpush ◽  
Azadeh Tavousi Tabatabaei
Keyword(s):  
Fourier Transform ◽  
Carbon Fiber ◽  
Ir Spectra ◽  
Fourier Transform Infrared ◽  
Fiber Composites ◽  
Carbon Fiber Composites ◽  
Heat Treated ◽  
Ft Ir ◽  
Post Industrial

Post-industrial off-cuts of carbon fiber epoxy and carbon fiber vinyl ester composites recycled mechanically and characterized by Fourier transform infrared (FT‐IR) to obtain an infrared spectrum of absorption or emission of the untreated and heat-treated recycled carbon fiber composites. FT‐IR spectra were recorded with a Bomem MB series FT‐IR spectrophotometer.

Extended Multiplicative Signal Correction as a Tool for Separation and Characterization of Physical and Chemical Information in Fourier Transform Infrared Microscopy Images of Cryo-Sections of Beef Loin

2005 ◽  
Vol 59 (6) ◽  
pp. 707-716 ◽  
Author(s):  
A. Kohler ◽  
C. Kirschner ◽  
A. Oust ◽  
H. Martens
Keyword(s):  
Heat Treatment ◽  
Fourier Transform ◽  
Ir Spectra ◽  
Fourier Transform Infrared ◽  
Optical Path Length ◽  
Chemical Information ◽  
Ir Microscopy ◽  
Signal Correction ◽  
Ft Ir ◽  
Physical And Chemical

Extended multiplicative signal correction (EMSC) is used to separate and to characterize physical and chemical information in spectra from Fourier transform infrared (FT-IR) microscopy. This appears especially useful for applications in infrared spectroscopy where the scatter variance in spectra changes with the chemical variance in the sample set. In these cases the chemical information of specific bands that are assigned to functional groups is easier to interpret when the scatter information is removed from the spectra. We show that scatter (physical) information in FT-IR spectra of heat-treated beef loin is related to chemical changes due to heat treatment. This information is caused by textural changes induced by the heat treatment and expressed by physical effects as the optical path length. The chemical absorbance changes introduced in the FT-IR spectra due to heat treatment are shifts in the protein region of the infrared spectrum caused by changes in the secondary structure of the proteins. If the scatter and the chemical information is not separated properly, scatter information may erroneously be interpreted as chemical information.

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