Nondestructive determination of the amphibole crystal‐chemical formulae by Raman spectroscopy: One step closer

Background: Food and herbal extracts rich in Quercetin (QRT) are often self-medicated by diabetics and can potentially alter the pharmacokinetics (PK) of Metformin HCl (MET) and Canagliflozin (CNG) leading to food or herb-drug interactions and reduced therapeutic efficacy. However, the impact of these flavonoids on the pharmacokinetic behaviour of MET and CNG is mostly unknown. Methods: A simple one-step protein precipitation method was developed for the determination of MET and CNG from rat plasma. The mobile phase chosen was MeOH 65% and 35% water containing 0.1% formic acid at a flow rate of 1mL/min. Results: The retention time of MET, internal standard (Valsartan) and CNG was 1.83, 6.2 and 8.2 min, respectively. The method was found to be linear in the range of 200 - 8000 ng/mL for CNG and 100 = 4000 ng/ml for MET. Precision and accuracy of the method were below 20% at LLOQ and below 15% for LQC, MQC, and HQC. Conclusion: The method was successfully applied for the determination of PK of MET and CNG by using 100 μL of rat plasma. QRT co-administration affects the PK parameters of MET and CNG. This alteration in PK parameters might be of significant use for clinicians and patients.

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Determination of Human Coronary Artery Composition by Raman Spectroscopy

Circulation ◽

10.1161/01.cir.96.1.99 ◽

1997 ◽

Vol 96 (1) ◽

pp. 99-105 ◽

Cited By ~ 107

Author(s):

James F. Brennan ◽

Tjeerd J. Römer ◽

Robert S. Lees ◽

Anna M. Tercyak ◽

John R. Kramer ◽

...

Keyword(s):

Raman Spectroscopy ◽

Coronary Artery ◽

Human Coronary Artery

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Multivariate Analysis Aided Surface-Enhanced Raman Spectroscopy (MVA-SERS) Multiplex Quantitative Detection of Trace Fentanyl in Illicit Drug Mixtures Using a Handheld Raman Spectrometer

Applied Spectroscopy ◽

10.1177/00037028211032930 ◽

2021 ◽

pp. 000370282110329

Author(s):

Ling Wang ◽

Mario O. Vendrell-Dones ◽

Chiara Deriu ◽

Sevde Doğruer ◽

Peter de B. Harrington ◽

...

Keyword(s):

Raman Spectroscopy ◽

Principal Component ◽

Surface Enhanced Raman Spectroscopy ◽

Quantitative Detection ◽

Least Squares Regression ◽

Surface Enhanced ◽

Surface Enhanced Raman ◽

Sers Detection ◽

Current Screening

Recently there has been upsurge in reports that illicit seizures of cocaine and heroin have been adulterated with fentanyl. Surface-enhanced Raman spectroscopy (SERS) provides a useful alternative to current screening procedures that permits detection of trace levels of fentanyl in mixtures. Samples are solubilized and allowed to interact with aggregated colloidal nanostars to produce a rapid and sensitive assay. In this study, we present the quantitative determination of fentanyl in heroin and cocaine using SERS, using a point-and-shoot handheld Raman system. Our protocol is optimized to detect pure fentanyl down to 0.20 ± 0.06 ng/mL and can also distinguish pure cocaine and heroin at ng/mL levels. Multiplex analysis of mixtures is enabled by combining SERS detection with principal component analysis and super partial least squares regression discriminate analysis (SPLS-DA), which allow for the determination of fentanyl as low as 0.05% in simulated seized heroin and 0.10% in simulated seized cocaine samples.

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Quantitative Determination of Oxytetracycline in Water-Based Liquid Dosage Forms by Raman Spectroscopy

Journal of Applied Spectroscopy ◽

10.1007/s10812-021-01147-x ◽

2021 ◽

Author(s):

A. Yu. Khrushchev ◽

E. R. Akmaev ◽

V. O. Bondarenko ◽

I. V. Kis

Keyword(s):

Raman Spectroscopy ◽

Quantitative Determination ◽

Dosage Forms ◽

Water Based

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Determination of ferroelastic phase transition temperature in BiVO4 by Raman spectroscopy

Materials Letters ◽

10.1016/j.matlet.2021.129519 ◽

2021 ◽

Vol 291 ◽

pp. 129519

Author(s):

Yuwaraj K. Kshetri ◽

Bina Chaudhary ◽

Takashi Kamiyama ◽

Tae-Ho Kim ◽

Federico Rosei ◽

...

Keyword(s):

Phase Transition ◽

Raman Spectroscopy ◽

Transition Temperature ◽

Phase Transition Temperature ◽

Ferroelastic Phase Transition

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Enhancement of a New Methodology Based on the Impulse Excitation Technique for the Nondestructive Determination of Local Material Properties in Composite Laminates

Applied Sciences ◽

10.3390/app11010101 ◽

2020 ◽

Vol 11 (1) ◽

pp. 101

Author(s):

Carlo Boursier Niutta

Keyword(s):

Resonant Frequency ◽

Elastic Properties ◽

Composite Laminates ◽

Concentrated Mass ◽

Modal Shape ◽

Nondestructive Determination ◽

Material Orientation ◽

Impulse Excitation ◽

Clamping System

A new approach for the nondestructive determination of the elastic properties of composite laminates is presented. The approach represents an improvement of a recently published experimental methodology based on the Impulse Excitation Technique, which allows nondestructively assessing local elastic properties of composite laminates by isolating a region of interest through a proper clamping system. Different measures of the first resonant frequency are obtained by rotating the clamping system with respect to the material orientation. Here, in order to increase the robustness of the inverse problem, which determines the elastic properties from the measured resonant frequencies, information related to the modal shape is retained by considering the effect of an additional concentrated mass on the first resonant frequency. According to the modal shape and the position of the mass, different values of the first resonant frequency are obtained. Here, two positions of the additional mass, i.e., two values of the resonant frequency in addition to the unloaded frequency value, are considered for each material orientation. A Rayleigh–Ritz formulation based on higher order theory is adopted to compute the first resonant frequency of the clamped plate with concentrated mass. The elastic properties are finally determined through an optimization problem that minimizes the discrepancy on the frequency reference values. The proposed approach is validated on several materials taken from the literature. Finally, advantages and possible limitations are discussed.

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Chlorine-Functional Silsesquioxanes (POSS-Cl) as Effective Flame Retardants and Reinforcing Additives for Rigid Polyurethane Foams

Molecules ◽

10.3390/molecules26133979 ◽

2021 ◽

Vol 26 (13) ◽

pp. 3979

Author(s):

Anna Strąkowska ◽

Sylwia Członka ◽

Karolina Miedzińska ◽

Krzysztof Strzelec

Keyword(s):

Flame Retardants ◽

Elevated Temperatures ◽

Bending Strength ◽

Reaction System ◽

Fire Retardant ◽

Polyurethane Foams ◽

Polymerization Reaction ◽

Three Point Bending ◽

One Step

The subject of the research was the production of silsesquioxane modified rigid polyurethane (PUR) foams (POSS-Cl) with chlorine functional groups (chlorobenzyl, chloropropyl, chlorobenzylethyl) characterized by reduced flammability. The foams were prepared in a one-step additive polymerization reaction of isocyanates with polyols, and the POSS modifier was added to the reaction system in an amount of 2 wt.% polyol. The influence of POSS was analyzed by performing a series of tests, such as determination of the kinetics of foam growth, determination of apparent density, and structure analysis. Compressive strength, three-point bending strength, hardness, and shape stability at reduced and elevated temperatures were tested, and the hydrophobicity of the surface was determined. The most important measurement was the determination of the thermal stability (TGA) and the flammability of the modified systems using a cone calorimeter. The obtained results, after comparing with the results for unmodified foam, showed a large influence of POSS modifiers on the functional properties, especially thermal and fire-retardant, of the obtained PUR-POSS-Cl systems.

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