In this study, we report the characterization of three arsenobetaine-certified reference materials by quantitative NMR. We have synthesized an arsenobetaine bromide high-purity standard of natural isotopic composition (ABET-1) and two carbon-13-labeled isotopic standards (BBET-1 and CBET-1). Assignments of the chemical purity and isotopic composition are not trivial in the case of arsenobetaine, and in this study we utilized quantitative(1)H-NMR techniques for the determination of the mass fractions (chemical purity). The isotopic purity of all three standards was also assessed by NMR from the carbon-13 satellite signals. The standards are non-hygroscopic, high-purity (ca. 0.99 g/g), and the carbon-13 enrichment for both isotopic standards is x((13)C)≈0.99. These standards are designed for use as primary calibrators for mass spectrometric determination of arsenobetaine in environmental samples.
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http://dx.doi.org/10.1007/s00216-016-9827-y | DOI Listing |
J Chromatogr A
December 2024
Key Laboratory of Biomass Chemical Engineering of Ministry of Education, Zhejiang Key Laboratory of Smart Biomaterials, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310058, China. Electronic address:
Development of a next-generation chromatographic model, capable of simultaneously meeting academic demands for thermodynamic consistency and industrial requirements in everyday project work, has become a focal point of research. In this study, anti-Langmuirian to Langmuirian (AL-L) elution behavior was observed in cation-exchange chromatographic separation of charge variants of industrial Fc-fusion proteins. To characterize this behavior, the multi-protein Mollerup activity model was integrated into the steric mass action (SMA) model, resulting in a new model named the generalized ion-exchange (nGIEX) isotherm for multi-protein systems.
View Article and Find Full Text PDFWaste Manag
December 2024
College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China.
With the exponential growth of global photovoltaic (PV) installed capacity, the quantity of discarded PV modules continues to rise. This study innovatively explored the sustainable recovery and utilization of raw materials from discarded solar panels, focusing on the transformation of recycled silicon into microporous silica nanoparticles (MSN). Low toxic organic solvent ethyl acetate (EA) was for the first time utilized to reduce the viscosity of ethylene-vinyl acetate (EVA) and facilitated its removal.
View Article and Find Full Text PDFWater Res
December 2024
Research Center for Membrane and Film Technology, Kobe University, 1-1 Rokkodaicho, Nada, Kobe 657-8501, Japan; Department of Chemical Science and Engineering, Kobe University, 1-1 Rokkodaicho, Nada, Kobe 657-8501, Japan. Electronic address:
Nanofiltration (NF) offers a scalable and energy-efficient method for lithium extraction from salt lakes. However, the selective separation of lithium from magnesium, particularly in brines with high magnesium concentrations, remains a significant challenge due to the close similarity in their hydrated ionic radii. The limited Li/Mgselectivity of current NF membranes is primarily attributed to insufficient control over pore size and surface charge.
View Article and Find Full Text PDFSmall
December 2024
Department of Chemistry & Chemical Biology and the Brockhouse Institute for Materials Research, McMaster University, 1280 Main St. W., Hamilton, ON, L8S 4M1, Canada.
Flexible sensors have garnered significant interest for their potential to monitor human activities and provide valuable feedback for healthcare purposes. Single-walled carbon nanotubes (SWNTs) are promising materials for these applications but suffer from issues of poor purity and solubility. Dispersing SWNTs with conjugated polymers (CPs) enhances solution processability, yet the polymer sidechains can insulate the SWNTs, limiting the sensor's operating voltage.
View Article and Find Full Text PDFFront Biosci (Elite Ed)
November 2024
Food Science Department, Agriculture College, Basrah University, 61001 Basrah, Iraq.
Background: Flavonoids are among the most important compounds found in plants, since laboratory studies have shown them to be a daily requirement in human diets due to their various health benefits. Therefore, this study focused on extracting, purifying, and measuring the antioxidant activity of the flavonoid quercetin, which is widely found in plants and possesses a variety of biological activities, from different plant sources.
Methods: The extraction of quercetin was performed using several methods (chemical, physical, and enzymatic) and several extraction solutions (water, ethanol, and chloroform) from several plants (spinach, dill, Onion Skin, , sumac, digalkhasab chemri, and leelwi chemri).
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