Journal of Spectroscopy

https://www.hindawi.com/journals/jspec/

List of Papers (Total 1,576)

FTIR and 1H-NMR studies of chiral (S)-(-)-2-methylbutyl 4′-(4″-hexyloxy-, (S)-(-)-2-methylbutyl 4′-(4″-(d13)-hexyloxy‒, (S)-(-)-2-methylbutyl 4′-(4″-octyloxy- and (S)-(-)-2-methylbutyl 4′-(4″-(d17)-octyloxyphenyl)benzoates

Four organic chiral compounds (S)-(-)-2-methylbutyl 4′-(4″-hexyloxy-, (S)-(-)-2-methylbutyl 4′-(4″-(d13)- hexyloxy-, (S)-(-)-2-methylbutyl 4′-(4″-octyloxy- and (S)-(-)-2-methylbutyl 4′-(4″-(d17)-octyloxy-phenyl)benzoates were synthesized via generalized methods and characterized by elemental analysis, FTIR and 1H NMR. A noticeable difference between the compounds which possess...

Ruthenium trisbipyridine as a candidate for gas-phase spectroscopic studies in a Fourier transform mass spectrometer

Metal polypyridines are excellent candidates for gas-phase optical experiments where their intrinsic properties can be studied without complications due to the presence of solvent. The fluorescence lifetimes of [Ru(bpy)3]1+ trapped in an optical detection cell within a Fourier transform mass spectrometer were obtained using matrix-assisted laser desorption/ionization to generate...

Structural analysis of proteins by isotope-edited FTIR spectroscopy

Structure determination of multidomain proteins or protein–membrane complexes is one of the most challenging tasks in modern structural biology. High-resolution techniques, like NMR or X-ray crystallography, are limited to molecules of moderate size or those that can be crystallized easily. Both methods encounter serious technical obstacles in structural analysis of protein...

Multivariate statistical evaluation of bone site and sex as parameters for the Fourier transform infrared spectroscopic study of normal bone

Fourier transform infrared spectroscopy combined with multivariate analysis was performed on a series of bone samples in order to investigate possible differences in the molecular fingerprint based on classification either between different sex and bone sites. Cortical femoral, tibia and ulna samples from five male and five female normal Wistar rats were analysed. PCA analysis...

Comparison of molecular structure of alkali metal ortho substituted benzoates

The influence of the amino-, nitro-, methoxy-, hydroxy- and chloro-substituents in the ortho position towards the carboxylic group as well as alkali metal on molecular structure of benzoates was estimated. Optimized geometrical structures were calculated by B3LYP/6-311++G** method. Experimental FT-IR, FT-Raman and NMR spectra of the title compounds were recorded and analyzed...

Modeling of cytochrome P450 (Cyt P450, CYP) channels

The precise location of a substrate in cytochrome P450 (CYP) governs the orientation of the oxidation position. Such information is generally obtained from biochemical data, but modeling approaches have also been used to explain these locations. We used X-ray data and modeling techniques to distinguish between the series of putative linear or curved channels which lead the...

Comparison of partial least squares and artificial neural network chemometric techniques in determination of sulfamethoxazole and trimethoprim in pharmaceutical suspension by ATR–FTIR spectrometry

Partial Least Square (PLS) and Artificial Neural Network (ANN) techniques were compared during development of an analytical method for quantitative determination of sulfamethoxazole (SMX) and trimethoprim (TMP) in Co-Trimoxazole® suspension. The procedure was based on Attenuated Total Reflectance Fourier Transform Infrared (ATR–FTIR) spectrometry. The 800–2500 cm−1 spectral...

Investigation of protein–protein interactions by isotope‒edited Fourier transformed infrared spectroscopy

Recent advance in FTIR spectroscopy has shown the usefulness of 13C uniform isotope labeling in proteins to study protein–protein interactions. 13C uniform isotope labeling can significantly resolve the spectral overlap in the amide I/I′ region in the spectra of protein–protein complexes, and therefore allows more accurate determination of secondary structures of individual...

Quantitative determination of naltrexone by attenuated total reflectance – FTIR spectrometry using partial least squares (PLS) wavelength selection

A new method is presented for quantitative determination of naltrexone in aqueous solutions based up on the wavelength selection in mid-FTIR spectra using partial least squares (PLS) technique. The main aim is to find wavelengths which produce significant improvements in PLS prediction. PLS wavelength selection treatment is performed on the data obtained by attenuated total...

Wireless near-infrared spectroscopy of skeletal muscle oxygenation and hemodynamics during exercise and ischemia

The majority of in vivo applications of near-infrared spectroscopic (NIRS) monitoring use continuous wave instruments that require a fiberoptic cable connection between the subject and the instrument during monitoring. In studies of muscle physiology where subjects are exercising, and particularly in those who are engaged in sports activity, a wireless instrument with telemetric...

Natural monoacetylenes studied by quantum-chemical chemistry

This study is a part of the project focused on the vibrational analysis of natural mono- and polyacetylenes by using Raman spectroscopy and theoretical calculations. Their vibrational spectra show strong and polarized –C≡C– bands in the region of about 2200 cm–1. Mono- as well as polyacetylenes are supposed to be active in plants yet not available in an isolated form, so...

Real-Time Release Testing of Herbal Extract Powder by Near-Infrared Spectroscopy considering the Uncertainty around Specification Limits

The concept of real-time release testing (RTRT) has recently been adopted by the production of pharmaceuticals in order to provide high-level guarantee of product quality. Process analytical technology (PAT) is an attractive and efficient way for realizing RTRT. In this paper, near-infrared (NIR) determination of cryptotanshinone and tanshinoneIIA content in tanshinone extract...

Near Infrared Spectroscopy Based on Supervised Pattern Recognition Methods for Rapid Identification of Adulterated Edible Gelatin

The aim of this work is to identify the adulteration of edible gelatin using near-infrared (NIR) spectroscopy combined with supervised pattern recognition methods. The spectral data obtained from a total of 144 samples consisting of six kinds of adulterated gelatin gels with different mixture ratios were processed with multiplicative scatter correction (MSC), Savitzky–Golay (SG...

Using Compact 1H NMR, NIR, and Raman Spectroscopy Combined with Multivariate Data Analysis to Monitor a Biocatalyzed Reaction in a Microreaction System

Process analytical technology aims at process knowledge and process improvement, efficiency, and sustainability. A prerequisite is process monitoring. The combination of microreaction systems and spectroscopy proved suitable due to dimension and compound reduction and real-time monitoring capabilities. Compact 1H NMR, NIR, and Raman spectroscopy were used to monitor the...

X-Ray-Induced Changes to Passivation Layers of Lithium-Ion Battery Electrodes

The surface sensitivity available to photoelectron spectroscopies (PESs) makes them popular techniques for characterization of chemical environments at shallower depths than other, more bulk-sensitive techniques and because they are generally thought to be nondestructive. Variable energy, synchrotron radiation (SR), permits access to information not available to common lab-based...

The Potential of the Quick Detection of Selectins Using Raman Spectroscopy to Discriminate Lung Cancer Patients from Healthy Subjects

This study aimed at determining the concentration of P-selectins in lung cancer patients in different stages and healthy subjects. Then, the ability of the methodology developed to discriminate the existence of lung cancer was also evaluated. Serum spectra were obtained using Raman spectroscopy (RS). Blood samples were taken from subjects divided into two groups: group 1...

Detailed Spectroscopic and Structural Analysis of TiO2/WO3 Composite Semiconductors

WO3-TiO2 composite materials were obtained using commercial titania (Evonik Aeroxide P25) and hydrothermally crystallized WO3. Different ratios of TiO2/WO3 were investigated, starting at 1 wt.% of WO3 to 50 wt.%. The morphology of WO3 was of the star-like type, and its structure is basically composed of monoclinic crystalline phase. All spectroscopic characteristics of the...

Analysis of the Core Oligosaccharide of Aeromonas hydrophila (Chemotype III) Lipopolysaccharide Using Fast Atom Bombardment, Electrospray and Low Energy Tandem Mass Spectrometry

Fast-atom bombardment mass spectrometry (FAB-MS) was employed for the structural analysis of the core oligosaccharide of Aeromonas hydrophila (Chemotype III) lipopolysaccharide. Positive ion FAB-MS of the underivatized core oligosaccharide gave the protonated molecular ion, confrrming the correct composition in terms of hexoses, heptoses and Kdo which was present as a bicyclic...

1H-NMR study of some new acetyl dimethylbiphenyls: unambiguous signal assignment for the methyl groups

The abundance 1H-NMR spectra of some new mono- and diacetyl compounds derived from 2,2′-dimethyl-, 3,3′-dimethyl-, and 4,4′-dimethylbiphenyls were recorded. Unambiguous signal assignment of the methyl groups of the aromatic biphenyl rings were made for the structure elucidation.

Solution and solid state (CPMAS) NMR studies of the tautomerism of six-membered heterocyclic compounds related to 2-pyridones

Several 13C and 15N chemical shifts of 2-pyridone (1), 4(3H)-pyrimidone (2), uracil (3) and cytosine (4) have been measured in solution and in the solid state. These data have been discussed in relation with the tautomerism of the four heterocycles. GIAO ab initio calculations of absolute shieldings have been carried out to identify the predominant tautomers in the case of...

REGRAS: an auxiliary program for pattern recognition and substructure elucidation of monoterpenes

The main purpose of this paper is to present a procedure that utilizes 13C NMR for pattern recognition and substructure elucidation of monoterpenes. By this reason, a novel version of the REGRAS program was developed for the specialist SISTEMAT system. This program carries out an analysis of the 13C NMR data from a given compound and, from characteristic chemical shift ranges...

Quantification of urine 17-ketosteroid sulfates and their age correlations

Dehydroepiandrosterone (DHEA) is a steroid secreted primarily by the adrenal gland and plays an important role as the primary precursor of many important sex steroids. The negative correlation between age and the secretion of DHEA (I) and in its sulfate form (II, DHEA-S) has been documented in human studies. Serum DHEA (I) and/or DHEA-S (II) levels have been associated with...