A rapid, precise, accurate, and robust method using capillary electrophoresis (CE) with dynamically coated capillaries for the analysis of the major opium alkaloids in opium is presented. Dynamic coating of the capillary surface is accomplished using a commercially available reagent kit (polycation coating followed by polyanion coating). The addition of dual cyclodextrins (hydroxypropyl-beta-cyclodextrin and dimethyl-beta-cyclodextrin) to the run buffer imparts excellent selectivity for the opium alkaloids. For the determination of morphine, papaverine, codeine, noscapine and thebaine in opium gum and opium latex samples (using tetracaine as an internal standard) good agreement with values obtained by gradient high-performance liquid chromatography is obtained. Compared to the latter technique, CE affords better resolution with significantly faster analysis time (12 min versus 29 min). Dynamically coated capillaries, which give rise to a relatively high and robust electroosmotic flow (EOF) at the background electrolyte pH of 2.5, allow for rapid analysis and excellent migration time and peak area precision (RSDs < or = 0.12% and < or = 1.2%, respectively). Reproducible separations (relative migration times) for over 500 samples have been obtained on a single capillary. The nature of the injection solvent, the injection time and the contents of the waste vials have a profound effect on the pressure injection precision of the relatively hydrophobic solutes. The CE conditions reported in this study are also applicable to the analysis of lysergic acid diethylamide (LSD) exhibits.
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http://dx.doi.org/10.1016/s0021-9673(02)01774-0 | DOI Listing |
Anal Methods
November 2017
Agricultural and Biological Engineering Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA.
Nitric oxide (NO) is an important signaling molecule that is involved in stress response, homeostasis, host defense, and cell development. In most cells, NO levels are in the femtomolar to micromolar range, with extracellular concentrations being much lower. Thus, real time measurement of spatiotemporal NO dynamics near the surface of living cells/tissues is a major challenge.
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, P. R. China.
Challenges emerge in the quest for highly efficient and biocompatible coatings to tackle microbial contamination. Here, we propose a bioinspired paradigm combining (-)-epigallocatechin gallate (EGCG) and l-arginine surfactants (LAM) as all-green building blocks for advanced coatings with superior performance. Molecular dynamics simulations reveal the natural assembly process of the EGCG/LAM supramolecular nanoparticles (ELA NPs).
View Article and Find Full Text PDFTissue Cell
January 2025
Institute of Biology and Biomedicine, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia. Electronic address:
The extracellular matrix (ECM) and its primary chemical components, including collagen, play a pivotal role in carcinogenesis and tumor progression. The ECM actively regulates cell proliferation, migration, and, importantly, resistance to various adverse factors. It is widely recognized as a key factor in modifying the resistance of tumor cells to various treatment modalities and cytotoxic compounds.
View Article and Find Full Text PDFTheranostics
January 2025
Department of Radiology, Functional and Molecular Imaging Key Lab of Shaanxi Province, Tangdu Hospital, Air Force Medical University, Xi'an, 710038, Shaanxi, China.
Next-generation wound dressings with multiple biological functions hold promise for addressing the complications and pain associated with burn wounds. A hydrogel wound dressing loaded with a pain-relieving drug was developed for treating infected burn wounds. Polyvinyl alcohol chemically grafted with gallic acid (PVA-GA), sodium alginate chemically grafted with 3-aminobenzeneboronic acid (SA-PBA), Zn, and chitosan-coated borneol nanoparticles with anti-inflammatory and pain-relieving activities were combined to afford a nanoparticle-loaded hydrogel with a PVA-GA/Zn/SA-PBA network crosslinked via multiple physicochemical interactions.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Liquid Sunlight Alliance, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States.
The electrochemical CO reduction reaction (CORR) holds enormous potential as a carbon-neutral route to the sustainable production of fuels and platform chemicals. The durability for long-term operation is currently inadequate for commercialization, however, and the underlying deactivation process remains elusive. A fundamental understanding of the degradation mechanism of electrocatalysts, which can dictate the overall device performance, is needed.
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