An on-line analytical method based on transmission near-infrared spectroscopy (NIRS) for the quantitative determination of water concentrations (in parts per million) was developed and applied to the manufacture of a pharmaceutical intermediate. Calibration models for water analysis, built at the development site and applied at the manufacturing site, were successfully demonstrated during six manufacturing runs at a 250-gallon scale. The water measurements will be used as a forward-processing control point following distillation of a toluene product solution prior to use in a Grignard reaction. The most significant impact of using this NIRS-based process analytical technology (PAT) to replace off-line measurements is the significant reduction in the risk of operator exposure through the elimination of sampling of a severely lachrymatory and mutagenic compound. The work described in this report illustrates the development effort from proof-of-concept phase to manufacturing implementation.
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http://dx.doi.org/10.1366/13-07260 | DOI Listing |
Photochem Photobiol
December 2024
Institute of Chemistry, State University of Campinas, Campinas, São Paulo, Brazil.
Given that non-equilibrium molecular motion in thermal gradients is influenced by both solute and solvent, the application of spectroscopic methods that probe each component in a binary mixture can provide insights into the molecular mechanisms of thermal diffusion for a large class of systems. In the present work, we use an all-optical setup whereby near-infrared excitation of the solvent leads to a steady-state thermal gradient in solution, followed by characterization of the non-equilibrium system with electronic spectroscopy, imaging, and intensity. Using rhodamine B in water as a case study, we perform measurements as a function of solute concentration, temperature, wavelength, time, near-infrared laser power, visible excitation wavelength, and isotope effect.
View Article and Find Full Text PDFChem Biomed Imaging
December 2024
Experimental Solid State Physics Group, Department of Physics, Imperial College, Exhibition Road, SW72AZ London, U.K.
Mesoporous silica nanoparticles (MSNPs) are promising nanomedicine vehicles due to their biocompatibility and ability to carry large cargoes. It is critical in nanomedicine development to be able to map their uptake in cells, including distinguishing surface associated MSNPs from those that are embedded or internalized into cells. Conventional nanoscale imaging techniques, such as electron and fluorescence microscopies, however, generally require the use of stains and labels to image both the biological material and the nanomedicines, which can interfere with the biological processes at play.
View Article and Find Full Text PDFPediatr Neonatol
December 2024
Department of Clinical and Experimental Medicine Section of Paediatrics and Child Neuropsychiatry, AUO Policlinico, University of Catania, Italy.
Objective: Near infrared spectroscopy (NIRS) is a non-invasive tool providing real-time continuous measurement of regional cerebral blood oxygenation and indirect blood flow. The aim of this review is to determine the best evidence to guide the use of NIRS to detect and avoid abnormalities of cerebral perfusion and oxygenation in newborns with bradycardia.
Design: For this systematic review according to PRISMA Statement, we reviewed papers from 2000 to 2023.
Environ Pollut
December 2024
Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture and Rural affairs, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China; Hubei Key Laboratory of Soil Environment and Pollution Remediation, College of Resources and Environment, Wuhan 430070, China. Electronic address:
Organoarsenicals are toxic pollutants of global concern, and their environmental geochemical behavior might be greatly controlled by iron (Fe) (hydr)oxides through coprecipitation, which is rarely investigated. Here, the effects of the incorporation of dimethylarsenate (DMAs(V)), a typical organoarsenical, into the ferrihydrite (Fh) structure on the mineral physicochemical properties and Fe(II)-induced phase transformation of DMAs(V)-Fh coprecipitates with As/Fe molar ratios up to 0.0876±0.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
December 2024
College of Information Science and Engineering, Henan University of Technology, Zhengzhou 450001, China; School of Automation, Northwestern Polytechnical University, Xi'an, China. Electronic address:
Wheat flour quality, determined by factors such as protein and moisture content, is crucial in food production. Traditional methods for analyzing these parameters, though precise, are time-consuming and impractical for large-scale operations. This study presents a lightweight convolutional neural network designed for real-time wheat flour quality monitoring using near-infrared spectroscopy.
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