Sampling unit for efficient signal detection and application to liquid chromatography-Raman spectroscopy

2021 ◽  
Author(s):  
Yu-Hao Lo ◽  
Shu-Chi Li ◽  
Hirotsugu Hiramatsu
Keyword(s):  
Raman Spectroscopy ◽  
Liquid Chromatography ◽  
Signal Detection ◽  
Signal Intensity ◽  
Sampling Unit ◽  
Raman Spectrometer ◽  
Unit Design

A new sampling unit design enhances the signal intensity and is available to combine Raman spectrometer with liquid chromatography.

Identification of Xylene Isomers in High-Pressure Liquid Chromatography Eluates by Raman Spectroscopy

1997 ◽  
Vol 51 (11) ◽  
pp. 1644-1647 ◽  
Author(s):  
Roland Steinert ◽  
Hans Bettermann ◽  
Karl Kleinermanns
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
Raman Spectrometer ◽  
Xylene Isomers

This contribution presents a combination of high-pressure liquid chromatography (HPLC) with a Raman spectrometer. With this approach, we have identified both isomer m-xylene and isomer p-xylene in solution at concentrations down to 10−5 mol/L. The setup was developed to analyze compounds that cannot be separated by using standard HPLC techniques.

scholarly journals Barium Titanium Oxynitride from Ammonia-Free Nitridation of Reduced BaTiO3

Inorganics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 62
Author(s):  
Hua Guo ◽  
Aleksander Jaworski ◽  
Zheng Chen ◽  
Can Lu ◽  
Adam Slabon ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Nmr Spectroscopy ◽  
Transition Metal ◽  
Signal Intensity ◽  
Diffuse Reflectance ◽  
Conduction Band Edge ◽  
Vacancy Ordering ◽  
Vis Spectroscopy ◽  
O Vacancy ◽  
Barium Titanium

We investigated the nitridation of reduced BaTiO3, BaTiO2.60H0.08, corresponding to an oxyhydride with a large concentration of O defects (>10%). The material is readily nitrided under flowing N2 gas at temperatures between 400 and 450 °C to yield oxynitrides BaTiO2.6Nx (x = 0.2−0.22) with a slightly tetragonally distorted perovskite structure, a ≈ 4.01 and c ≈ 4.02 Å, and Ti partially remaining in the oxidation state III. The tetragonal structure was confirmed from Raman spectroscopy. 14N MAS NMR spectroscopy shows a single resonance at 270 ppm, which is typical for perovskite transition metal oxynitrides. However, largely different signal intensity for materials with very similar N content suggests N/O/vacancy ordering when prolonging nitridation times to hours. Diffuse reflectance UV-VIS spectroscopy shows a reduction of the intrinsic band gap to 2.4–2.45 eV compared to BaTiO3 (~3.2 eV). Mott-Schottky measurements confirm n-type conductivity and reveal a slight negative shift of the conduction band edge from –0.59 V (BaTiO3) to ~–0.65 eV.

scholarly journals Polarization Dependence of Low-Frequency Vibrations from Multiple Faces in an Organic Single Crystal

Crystals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 425 ◽  
Author(s):  
Nemtsov ◽  
Aviv ◽  
Mastai ◽  
Tischler
Keyword(s):  
Raman Spectroscopy ◽  
Intermolecular Interactions ◽  
Signal Intensity ◽  
Structural Information ◽  
Low Frequency ◽  
Incident Beam ◽  
Optical Filters ◽  
Polarization Dependence ◽  
Raman Signal ◽  
Shear Modes

Recent developments in optical filters have enabled the facile use of Raman spectroscopy for detection of low frequency (LF) vibrational modes. LF-Raman spectroscopy offers fast and sensitive characterization of LF vibrations, and enables the measurement of single microcrystals and detection of defects. It is useful for probing intermolecular interactions in crystals, which are lower in energy, such as hydrogen bonds, shear modes, and breathing modes. Crystal excitation from multiple faces allows learning the orientation of intermolecular interactions, as polarization dependence varies with the polarizability of the interactions along the planes. Elucidating the orientations of the intermolecular interactions in organic crystals is essential for guiding the reactions or adsorption to a specific crystal face. In this study, we investigated the dependence of the LF-Raman signal intensity on the orientation of an organic single microcrystal of L-alanine. Three incident beam directions provided the orientations of the intermolecular interactions by analyzing the corresponding LF-Raman spectra. The signal intensity correlated well with the proximity between the incident beam’s direction and the orientations of the intermolecular interactions. Excellent compatibility was found between the spectra and simulated orientations based on structural information.

Signal detection limit of a portable Raman spectrometer for the SERS detection of gunshot residue

2019 ◽  
Vol 9 (3) ◽  
pp. 948-955 ◽  
Author(s):  
Evan Thayer ◽  
Wilson Turner ◽  
Stephen Blama ◽  
Mary Sajini Devadas ◽  
Ellen M. Hondrogiannis
Keyword(s):  
Detection Limit ◽  
Signal Detection ◽  
Gunshot Residue ◽  
Raman Spectrometer ◽  
Sers Detection ◽  
Image Position ◽  
Portable Raman

Abstract

scholarly journals Non-destructive analysis of drug content in polymer coatings with Raman spectroscopy

2019 ◽  
Vol 5 (1) ◽  
pp. 469-471
Author(s):  
Thomas Reske ◽  
Katharina Wulf ◽  
Thomas Eickner ◽  
Niels Grabow ◽  
Klaus-Peter Schmitz ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Liquid Chromatography ◽  
High Performance ◽  
Quantitative Methods ◽  
Sample Surface ◽  
Polymer Coatings ◽  
Drug Content ◽  
Special Sample Preparation ◽  
Rectangular Area ◽  
Cost Efficient

AbstractThe analysis of device drug content typically is carried out by means of chromatographic methods such as high performance liquid chromatography (HPLC) or liquid chromatography-mass spectrometry (LCMS). These approved methods are particularly fast, cost-efficient and ubiquitous in chemical-analytical laboratories. However, these quantitative methods necessitate the drug being eluted, which represents a destructive process. A novel alternative to these well-established methods [1, 2] is the Raman spectroscopy, which is fast and cost-efficient, as well [3]. Additionally, it offers the advantage of nondestructive analysis without the need for a special sample preparation. Within the current investigation we applied Raman spectroscopy for the qualitative and quantitative analysis of dexamethasone (DMS), a glucocorticoid, incorporated in a silicone matrix. The investigation was conducted in a rectangular area on the sample surface. The required number of measuring points (spectra) was determined. Calibration was performed with samples containing different amounts of DMS. The evaluation of Raman spectra is based on the analysis of the peak areas of the bands at 795 rel. cm-1(silicone) and 1,663 rel. cm-1(DMS). Remarkably, next to a precise overview of DMS distribution, an exact and reproducible quantification of incorporated DMS could be obtained.

Fabrication of 50 nm scale Pt nanostructures by block copolymer (BCP) and its characteristics of surface-enhanced Raman scattering (SERS)

RSC Advances ◽  
2016 ◽  
Vol 6 (75) ◽  
pp. 70756-70762 ◽  
Author(s):  
Jae Hee Shin ◽  
Hyun Gu Kim ◽  
Gwang Min Baek ◽  
Reehyang Kim ◽  
Suwan Jeon ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Block Copolymer ◽  
Raman Scattering ◽  
Signal Intensity ◽  
Surface Enhanced Raman Scattering ◽  
Important Phenomenon ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering

Surface-enhanced Raman scattering (SERS) represents an important phenomenon that can solve the low signal intensity of Raman spectroscopy. In this study, we investigated the effect of various Pt nanostructures on the sensitivity of SERS.

Surface-enhanced Raman spectroscopy (SERS) for detection of VX and HD in the gas phase using a hand-held Raman spectrometer

The Analyst ◽  
2020 ◽  
Vol 145 (19) ◽  
pp. 6334-6341 ◽  
Author(s):  
Vered Heleg-Shabtai ◽  
Hagai Sharabi ◽  
Amalia Zaltsman ◽  
Izhar Ron ◽  
Alexander Pevzner
Keyword(s):  
Raman Spectroscopy ◽  
Gas Phase ◽  
Surface Enhanced Raman Spectroscopy ◽  
Sers Substrate ◽  
Raman Spectrometer ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

A sensitive surface-enhanced Raman spectroscopy (SERS) substrate was developed to enable hand-held Raman spectrometers to detect gas-phase VX and HD.

scholarly journals Integrating liquid chromatography mass spectrometry into an analytical protocol for the identification of organic colorants in Japanese woodblock prints

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Marc Vermeulen ◽  
Diego Tamburini ◽  
Emily M. K. Müller ◽  
Silvia A. Centeno ◽  
Elena Basso ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Raman Spectroscopy ◽  
Liquid Chromatography ◽  
Multispectral Imaging ◽  
Surface Enhanced Raman Spectroscopy ◽  
Carthamus Tinctorius ◽  
Edo Period ◽  
Woodblock Prints ◽  
Surface Enhanced Raman ◽  
Japanese Woodblock Prints

AbstractThree Japanese woodblock prints from the Edo period (1603–1868) underwent a scientific investigation with the aim of understanding the changes in the colorants used in Japanese printing techniques. A multi-analytical approach was adopted, combining non-invasive techniques, such as fiber optic reflectance spectroscopy (FORS), Raman spectroscopy, multispectral imaging (MSI), and macro X-ray fluorescence (MA-XRF) with minimally invasive surface-enhanced Raman spectroscopy (SERS). The results enabled many of the pigments to be identified and their distribution to be studied, apart from two shades of purple of organic composition. Consequently, the potential of high-pressure liquid chromatography tandem mass spectrometry (HPLC–MS/MS) was explored for the first time with application to Japanese woodblock prints. The intrinsic sensitivity of the instrument and an effective extraction protocol allowed us to identify a mixture of dayflower (Commelina communis) blue and safflower (Carthamus tinctorius) red in purple samples constituted of 2–3 single fibers. In addition to the innovative integration of MA-XRF and HPLC–MS/MS to investigate these delicate artworks, the study concluded on the use of traditional sources of colors alongside newly introduced pigments in late Edo-period Japan. This information is extremely important for understanding the printing practices, as well as for making decisions about display, conservation, and preservation of such artworks.

scholarly journals Advantages and disadvantages of Raman spectroscopy in testing paper banknotes

2019 ◽  
Vol 13 (3) ◽  
pp. 226-229 ◽  
Author(s):  
Gordana Jauković
Keyword(s):  
Physical Chemistry ◽  
Raman Spectroscopy ◽  
Wave Length ◽  
Raman Signal ◽  
Raman Spectrometer ◽  
Advantages And Disadvantages ◽  
Private Collection ◽  
Spectrum Characteristic

This paper presents advantages and disadvantages of Raman spectroscopy when used for testing banknotes, i.e. in case study I, 1 and 5 dinars banknotes from a private collection dating from 1876 of numismatic value were analyzed, and in case study II, 1000 dinars banknote from circulation together with its counterfeit. In both cases banknotes were analyzed by using Raman spectrometer DXR Raman microscope at the Faculty of Physical Chemistry, with a laser of wave-length 780 nm at 12 mW of power. Specters were recorded under microscope using 50X lens in a range 1800-60 cm-1. Analyses from case study I on both specimens showed spectrum characteristic for fluorescence appearance, therefore intensive signal of fluorescence covered Raman signal. In case study II, it was established that Raman spectroscopy can reliably detect a counterfeit banknote. Research, comparisons and analyses regarding original and counterfeit 1000 dinars note were performed on red banknote surfaces.

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