In this work, in situ Raman spectroscopy is applied in a quantitative manner to crystal suspensions during crystallization in order to monitor a solvent-mediated polymorph transformation without the use of a calibration model. Assuming a linear dependency of the Raman signal intensity on the solute and on the solid concentrations of both solid-state forms, the measured time-resolved Raman spectra are fitted directly using a detailed model that describes the time evolution of the process. The applicability of this novel method is demonstrated thoroughly through the application to synthetic data of unseeded and seeded transformations as well as to various seeded polymorph transformation experiments. The resulting concentration profiles show a good agreement with the concentrations obtained by a multivariate calibration model. Additionally, the estimated kinetic parameters are compared to parameters obtained through fitting the solid-phase composition profiles that result from the calibration. The discrepancy between the estimated model parameters is small, and essentially the same descriptive process model is obtained. However, by fitting the time-resolved Raman spectra directly, a significant amount of calibration effort can be avoided.
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http://dx.doi.org/10.1021/ac801606z | DOI Listing |
Chem Pharm Bull (Tokyo)
January 2025
Department of Molecular Pharmaceutics, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan.
Optimization of the manufacturing process based on scientific evidence is essential for quality control of active pharmaceutical ingredients. Real-time monitoring can ensure the production of stable quality crystals in the crystallization process. Raman spectroscopy is an attractive tool for pharmaceutical quality evaluation and process analytical technology because of its ability to analyze samples non-destructively and rapidly.
View Article and Find Full Text PDFAnal Chim Acta
March 2025
Zhejiang Key Laboratory of Advanced Optical Functional Materials and Devices, Ningbo University, Ningbo, 315211, China; Engineering Research Center for Advanced Infrared Photoelectric Materials and Devices of Zhejiang Province, Ningbo University, Ningbo, 315211, China. Electronic address:
Background: Permethrin is a pesticide used to kill insects, and once used in excess, it poses a great threat to the environment and human health, therefore, it is necessary to realize the rapid and accurate detection of permethrin. Fiber optic surface enhanced Raman scattering (SERS) probes have the advantages of small volume and can be used for remote monitoring, which have great potential for application in achieving in-situ detection of pesticide residues.
Results: Fiber taper waist (FTW) SERS probes modified by silver nanocubes-graphene oxide (Ag NCs-GO) composite structures were prepared for in situ detection of permethrin in lake water.
Chem Commun (Camb)
January 2025
Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, P. R. China.
Long-range ordered high-entropy intermetallics (HEIs) were synthesized a thermodynamically-driven atomic ordering strategy. The (FeCoNi)(RuPt) HEI achieves 200 mA cm at an overpotential of 56 mV and a remarkable low Tafel slope of 50.4 mV dec in alkaline seawater.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Jilin University, State Key Laboratory of Supramolecular Structure and Materials, 2699 Qianjin Street, 130012, Changchun, CHINA.
To date, few systematic approach has been established for predicting catalytic performance by analyzing the spectral information of molecules adsorbed on photocatalyst surfaces. Effective charge transfer (CT) between the semiconductor photocatalysts and surface-absorbed molecules is essential for enhancing catalytic activity and optimizing light energy utilization. This study aimed to validate the surface-enhanced Raman spectroscopy (SERS) based on the CT enhancement mechanism in investigating the CT process during semiconductor photocatalytic C-C coupling model reactions.
View Article and Find Full Text PDFThe Raman characterization results of lunar relevant simulants, including liquid water, ice, and organics using NASA Langley developed standoff ultra-compact micro-Raman (SUCR) sensor are presented. The SUCR sensor is designed as an instrument applicable for future lunar surface operations. The SUCR is equipped to be mounted on a lunar lander's platform or on a rover's robotic arm for close Raman inspection of mixed samples on the lunar surface, including mapping the mineralogy, determining water ice distribution, and identifying frozen volatiles.
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