scholarly journals Assisted Interpretation of Laser-Induced Fluorescence Spectra of Egg-Based Binding Media Using Total Emission Fluorescence Spectroscopy

2006 ◽  
Vol 2006 ◽  
pp. 1-5 ◽  
Author(s):  
Austin Nevin ◽  
Demetrios Anglos
Keyword(s):  
Amino Acids ◽  
Fluorescence Spectroscopy ◽  
Fluorescence Spectra ◽  
Emission Spectra ◽  
Egg Yolk ◽  
Laser Induced Fluorescence ◽  
Oxidation Products ◽  
Total Emission ◽  
Binding Media ◽  
Age Related

Laser-induced fluorescence (LIF) spectroscopy can provide nondestructive, qualitative analysis of protein-based binding media found in artworks. Fluorescence emissions from proteins in egg yolk and egg white are due to autofluorescent aromatic amino acids as well as other native and age-related fluorophores, but the potential of fluorescence spectroscopy for the differentiation between binding media is dependent on the choice of a suitable excitation wavelength and limited by problems in interpretation. However, a better understanding of emission spectra associated with LIF can be achieved following comparisons with total emission fluorescence spectra where a series of consecutive emission spectra are recorded over a specific range. Results using nanosecond UV laser sources for LIF of egg-based binding media are presented which are rationalised following comparisons with total emission spectra. Specifically, fluorescence is assigned to tryptophan and oxidation products of amino acids; in the case of egg yolk, fatty-acid polymerisation and age-related degradation products account for the formation of fluorophores.

scholarly journals Remote Laser Induced Fluorescence of Soils and Rocks

Photonics ◽  
2021 ◽  
Vol 8 (10) ◽  
pp. 411
Author(s):  
Vasily N. Lednev ◽  
Alexey F. Bunkin ◽  
Sergey M. Pershin ◽  
Mikhail Ya. Grishin ◽  
Diana G. Artemova ◽  
...  
Keyword(s):  
Fluorescence Spectroscopy ◽  
Fluorescence Spectra ◽  
Space Exploration ◽  
Laser Induced Fluorescence ◽  
Excitation Wavelength ◽  
Extraterrestrial Life ◽  
Future Space ◽  
Lidar Sensing ◽  
First Time ◽  
Different Soils

The laser induced fluorescence spectroscopy was systematically utilized for remote sensing of different soils and rocks for the first time, to the best of our knowledge. Laser induced fluorescence spectroscopy measurements were carried out by the developed nanosecond LIDAR instrument with variable excitation wavelength (355, 532 and 1064 nm). LIDAR sensing of different Brazil soil samples have been carried out in order to construct a spectral database. The laser induced fluorescence spectra interpretation for different samples has been discussed in detail. The perspectives of LIDAR sensing of organic samples deposited at soils and rock have been discussed including future space exploration missions in the search for extraterrestrial life.

UV Time-Resolved Laser-Induced Fluorescence Spectroscopy of Amino Acids Found in Meteorites: Implications for Space Science and Exploration

Astrobiology ◽  
2021 ◽  
Author(s):  
Elizabeth A. Lymer ◽  
Menelaos Konstandtinidis ◽  
Emmanuel A. Lalla ◽  
Michael G. Daly ◽  
Kimberly T. Tait
Keyword(s):  
Amino Acids ◽  
Fluorescence Spectroscopy ◽  
Laser Induced Fluorescence ◽  
Space Science ◽  
Time Resolved

Laser-induced fluorescence and discharge emission spectra of CrO. Rotational analysis of the A5Π–X5Π transition

1980 ◽  
Vol 58 (4) ◽  
pp. 516-533 ◽  
Author(s):  
W. H. Hocking ◽  
A. J. Merer ◽  
D. J. Milton ◽  
W. E. Jones ◽  
G. Krishnamurty
Keyword(s):  
Fluorescence Spectra ◽  
Rotational Temperature ◽  
Electronic States ◽  
Emission Spectra ◽  
Laser Induced Fluorescence ◽  
Spin Orbit Coupling ◽  
Excitation Spectra ◽  
Large Numbers ◽  
Parallel Polarization ◽  
Indirect Information

The A5Π–X5Π electronic transition of CrO, near 6000 Å, has been analysed in detail using laser-induced fluorescence and conventional discharge emission spectroscopy. The transition provides the first instance where it has been possible to analyse the rotational structures of quintet electronic states completely. Although the parallel polarization of the transition has prevented the spin–orbit coupling and Λ-doubling intervals from being observed directly, it is shown that sufficient indirect information exists in the spectrum for them to be obtained with fair precision. The excited state, A5Π, is perturbed by large numbers of other electronic states which have no intensity of their own for emission to the ground state. The analysis of the perturbed regions has been greatly facilitated by the laser-induced fluorescence spectra: the excitation spectra correspond to a rotational temperature close to room temperature (which offers a significant improvement in resolution over the discharge spectra), and the J-assignments of the perturbed lines given by the resolved fluorescence spectra are unambigious

scholarly journals Monitoring Virgin Olive Oil Shelf-Life by Fluorescence Spectroscopy and Sensory Characteristics: A Multidimensional Study Carried Out under Simulated Market Conditions

Foods ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1846
Author(s):  
Ana Lobo-Prieto ◽  
Noelia Tena ◽  
Ramón Aparicio-Ruiz ◽  
Diego L. García-González ◽  
Ewa Sikorska
Keyword(s):  
Fluorescence Spectroscopy ◽  
Shelf Life ◽  
Olive Oil ◽  
Fluorescence Spectra ◽  
Virgin Olive Oil ◽  
Sensory Characteristics ◽  
Oxidation Products ◽  
Chlorophyll Pigments ◽  
Multiple Parameters ◽  
Physical Chemical

The control of virgin olive oil (VOO) freshness requires new tools that reflect the diverse chemical changes that take place during the market period. Fluorescence spectroscopy is one of the techniques that has been suggested for controlling virgin olive oil (VOO) freshness during its shelf-life. However, a complete interpretation of fluorescence spectra requires analyzing multiple parameters (chemical, physical–chemical, and sensory) to evaluate the pace of fluorescence spectral changes under moderate conditions with respect to other changes impacting on VOO quality. In this work, four VOOs were analyzed every month with excitation–emission fluorescence spectra. The same samples were characterized with the concentration of fluorophores (phenols, tocopherols, chlorophyll pigments), physical–chemical parameters (peroxide value, K232, K270, free acidity), and sensory attributes (medians of defects and of the fruity attribute). From the six components extracted with parallel factor analysis (PARAFAC), two components were assigned to chlorophyll pigments and those assigned to tocopherols, phenols, and oxidation products were selected for their ability to discriminate between fresh and aged oils. Thus, the component assigned to oxidation products correlated with K270 in the range 0.80–0.93, while the component assigned to tocopherols–phenols correlated with the fruity attribute in the range 0.52–0.90. The sensory analysis of the samples revealed that the changes of these PARAFAC components occurred at the same time as, or even before, the changes of the sensory characteristics.

Speciation study on complex formation of uranium(VI) with phosphate and fluoride at high temperatures and pressures by time-resolved laser-induced fluorescence spectroscopy

2004 ◽  
Vol 92 (12) ◽  
Author(s):  
Akira Kirishima ◽  
Takaumi Kimura ◽  
Osamu Tochiyama ◽  
Zenko Yoshida
Keyword(s):  
Complex Formation ◽  
Fluorescence Spectroscopy ◽  
High Temperatures ◽  
Elevated Temperatures ◽  
Emission Spectra ◽  
Laser Induced Fluorescence ◽  
Time Resolved ◽  
Speciation Study

SummaryThe complex formation of U(VI) with phosphate and with fluoride has been studied at elevated temperatures (20–150 °C) and pressures (0.1–40 MPa) using time-resolved laser-induced fluorescence spectroscopy (TRLFS). Emission spectra and lifetimes of 5×10

Fluorescence spectroscopy of mechanical pulps III: Effect of chlorite delignification

1995 ◽  
Vol 73 (11) ◽  
pp. 1955-1959 ◽  
Author(s):  
Jennifer A. Olmstead ◽  
Jian H. Zhu ◽  
Derek G. Gray
Keyword(s):  
Fluorescence Spectroscopy ◽  
Fluorescence Intensity ◽  
Fluorescence Spectra ◽  
Lignin Content ◽  
Emission Spectra ◽  
Thermomechanical Pulp ◽  
Fluorescence Excitation ◽  
Lignin Removal ◽  
Mechanical Pulps ◽  
Almost All

Many paper and wood samples fluoresce, but the sources of the emission are not well understood. Fluorescence excitation and emission spectra of paper sheets prepared from thermomechanical pulp (TMP) and bleached chemithermomechanical pulp (BCTMP) showed that the emission from the BCTMP was significantly higher than that from the TMP. Removing almost all of the lignin from both pulps by means of an acid chlorite treatment did not reduce the fluorescence significantly. By means of an approximate correction for changes in sheet reflectivity caused by the chlorite treatment, the fluorescence intensity was found to increase with lignin removal. Clearly, fluorescence is not simply related to lignin content. Keywords: wood pulp, lignin, cellulose, fluorescence spectra, acid chlorite delignification.

Fluorescence Spectroscopy for Rapid Detection and Classification of Bacterial Pathogens

2009 ◽  
Vol 63 (11) ◽  
pp. 1251-1255 ◽  
Author(s):  
Miryeong Sohn ◽  
David S. Himmelsbach ◽  
Franklin E. Barton ◽  
Paula J. Fedorka-Cray
Keyword(s):  
Fluorescence Spectroscopy ◽  
Rapid Detection ◽  
Fluorescence Spectra ◽  
Pathogenic Bacteria ◽  
Bacterial Pathogens ◽  
Emission Spectra ◽  
Principal Component ◽  
Minimal Sample ◽  
Synchronous Scan

This study deals with the rapid detection and differentiation of Escherichia coli, Salmonella, and Campylobacter, which are the most commonly identified commensal and pathogenic bacteria in foods, using fluorescence spectroscopy and multivariate analysis. Each bacterial sample cultured under controlled conditions was diluted in physiologic saline for analysis. Fluorescence spectra were collected over a range of 200–700 nm with 0.5 nm intervals on the PerkinElmer Fluorescence Spectrometer. The synchronous scan technique was employed to find the optimum excitation (λex) and emission (λem) wavelengths for individual bacteria with the wavelength interval (Δλ) being varied from 10 to 200 nm. The synchronous spectra and two-dimensional plots showed two maximum λex values at 225 nm and 280 nm and one maximum λem at 335–345 nm (λem=λex + Δλ), which correspond to the λex=225 nm, Δλ=110–120 nm, and λex=280 nm, Δλ=60–65 nm. For all three bacterial genera, the same synchronous scan results were obtained. The emission spectra from the three bacteria groups were very similar, creating difficulty in classification. However, the application of principal component analysis (PCA) to the fluorescence spectra resulted in successful classification of the bacteria by their genus as well as determining their concentration. The detection limit was approximately 103–104 cells/mL for each bacterial sample. These results demonstrated that fluorescence spectroscopy, when coupled with PCA processing, has the potential to detect and to classify bacterial pathogens in liquids. The methology is rapid (<10 min), inexpensive, and requires minimal sample preparation compared to standard analytical methods for bacterial detection.

Spectral features of biogenic calcium carbonates and implications for astrobiology

2014 ◽  
Vol 13 (4) ◽  
pp. 353-365 ◽  
Author(s):  
B. L. Berg ◽  
J. Ronholm ◽  
D. M. Applin ◽  
P. Mann ◽  
M. Izawa ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Organic Matter ◽  
Fluorescence Spectroscopy ◽  
Emission Spectra ◽  
Reflectance Spectroscopy ◽  
Laser Induced Fluorescence ◽  
Spectroscopic Techniques ◽  
Absorption Bands ◽  
Calcium Carbonates ◽  
Biogenic Carbonates

AbstractThe ability to discriminate biogenic from abiogenic calcium carbonate (CaCO3) would be useful in the search for extant or extinct life, since CaCO3can be produced by both biotic and abiotic processes on Earth. Bioprecipitated CaCO3material was produced during the growth of heterotrophic microbial isolates on medium enriched with calcium acetate or calcium citrate. These biologically produced CaCO3, along with natural and synthetic non-biologically produced CaCO3samples, were analysed by reflectance spectroscopy (0.35–2.5 μm), Raman spectroscopy (532 and 785 nm), and laser-induced fluorescence spectroscopy (365 and 405 nm excitation). Optimal instruments for the discrimination of biogenic from abiogenic CaCO3were determined to be reflectance spectroscopy, and laser-induced fluorescence spectroscopy. Multiple absorption features in the visible light region occurred in reflectance spectra for most biogenic CaCO3samples, which are likely due to organic pigments. Multiple fluorescence peaks occurred in emission spectra (405 nm excitation) of biogenic CaCO3samples, which also are best attributed to the presence of organic compounds; however, further analyses must be performed in order to better determine the cause of these features to establish criteria for confirming the origin of a given CaCO3sample. Raman spectroscopy was not useful for discrimination since any potential Raman peaks in spectra of biogenic carbonates collected by both the 532 and 785 nm lasers were overwhelmed by fluorescence. However, this also suggests that biogenic carbonates may be identified by the presence of this organic-associated fluorescence. No reliable spectroscopic differences in terms of parameters such as positions or widths of carbonate-associated absorption bands were found between the biogenic and abiogenic carbonate samples. These results indicate that the presence or absence of organic matter intimately associated with carbonate minerals is the only potentially useful spectral discriminator for the techniques that were examined, and that multiple spectroscopic techniques are capable of detecting the presence of associated organic materials. However, the presence or absence of intimately associated organic matter is not, in itself, an indicator of biogenicity.

Analysis of protein-based binding media found in paintings using laser induced fluorescence spectroscopy

2006 ◽  
Vol 573-574 ◽  
pp. 341-346 ◽  
Author(s):  
Austin Nevin ◽  
Sharon Cather ◽  
Demetrios Anglos ◽  
Costas Fotakis
Keyword(s):  
Fluorescence Spectroscopy ◽  
Laser Induced Fluorescence ◽  
Binding Media
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