Background: In the past three decades, liquid chromatography (LC) has been recognized as a significant environmental, health, and safety burden due to its heavy reliance on toxic organic solvents. Various chromatographic modes are in vogue today for complex analyses, such as sub/supercritical fluid chromatography (SFC) and enhanced fluidity liquid chromatography (EFLC). These modes are often advertised as "universally green" compared to the traditional allliquid reversed (RPLC) and normal phases (NPLC). Quantitative greenness evaluations must be done to validate or invalidate this assumption and allow separation scientists to make educated choices when deciding on what mode to use.
Results: In this work, we modify the Analytical Method Greenness Score (AMGS) to include the cycle time of the instrument, and with the help of the first-order optimality condition (by setting the AMGS gradient = 0), we show that SFC and EFLC are not always the greenest option as they are often thought to be. Most of the greenness metrics have ignored the cycle time of instruments, yet this key component changes the entire AMGS response to flow rate. The complex case of separating tobacco alkaloid enantiomers (nicotine, nornicotine, anabasine, and anatabine) was selected as an illustrative example for comparing and contrasting separation modes using the modified greenness metric. These enantiomers have been selected due to their notorious difficulty in separation over the past 30 years. Using this family of molecules, four unique retention patterns were observed covering a wide variety of retention phenomena seen in small molecule enantioseparations.
Significance: The modified AMGS metric will assist practicing analytical chemists in assessing the environmental impact of their separation methods from a single run in a given chromatographic mode. The proposed methodology identifies the minimum AMGS score corresponding to the greenest separation for routine chemical analysis.
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http://dx.doi.org/10.1016/j.aca.2024.343288 | DOI Listing |
Nature
January 2025
Xanadu Quantum Technologies Inc., Toronto, Ontario, Canada.
Photonics offers a promising platform for quantum computing, owing to the availability of chip integration for mass-manufacturable modules, fibre optics for networking and room-temperature operation of most components. However, experimental demonstrations are needed of complete integrated systems comprising all basic functionalities for universal and fault-tolerant operation. Here we construct a (sub-performant) scale model of a quantum computer using 35 photonic chips to demonstrate its functionality and feasibility.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
January 2025
School of Chemistry, University of East Anglia, Norwich NR4 7TJ, U.K.
Understanding the role of structural and environmental dynamics in the excited state properties of strongly coupled chromophores is of paramount importance in molecular photonics. Ultrafast, coherent, and multidimensional spectroscopies have been utilized to investigate such dynamics in the simplest model system, the molecular dimer. Here, we present a half-broadband two-dimensional electronic spectroscopy (HB2DES) study of the previously reported ultrafast symmetry-breaking charge separation (SB-CS) in the subphthalocyanine oxo-bridged homodimer μ-OSubPc.
View Article and Find Full Text PDFJ Chromatogr A
January 2025
Department of Chemical and Process Engineering, Rzeszów University of Technology, Rzeszów/PL. Electronic address:
Separation of a monoclonal antibody (mAb) from impurities was examined on different cation exchange resins (CEX), including POROS XS, POROS HS, NUVIA S, and NUVIA HRS. Impurities mainly consisted of cell culture-derived mAb fragments, or lysozyme, that mimicked the presence of an adsorbing protein of low molecular weight. The choice between the flowthrough mode and the bind-and-elute mode for the purification was guided by the shape of the adsorption isotherm.
View Article and Find Full Text PDFMed Sci Sports Exerc
January 2025
School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, AUSTRALIA.
Purpose: We hypothesized that male and female volunteers would exhibit distinct changes in cardiac morphology, systolic, and diastolic function following endurance (END) and resistance (RES) training.
Methods: Thirty-eight females and 26 males participated in a randomized cross-over design trial in which all participants completed 12-weeks END and RES, separated by a 12-week washout. Echocardiograms assessed morphology (left ventricular mass, LVM), systolic function (ejection fraction, EF, and global longitudinal strain, GLS), diastolic function (mitral valve velocities, E, A; tissue Doppler velocities, e', a'), and left atrial volume.
J Exp Bot
January 2025
Plant-Fusarium Interactions Research Team, School of BioSciences, University of Melbourne, Parkville, Australia.
Jasmonic acid (JA), ethylene (ET) and salicylic acid (SA) are the three major phytohormones coordinating plant defense responses, and all three are implicated in the defense against the fungal pathogen Fusarium oxysporum. However, their distinct modes of action and possible interactions remain unknown, in part because all spatial information on their activity is lacking. Here, we set out to probe this spatial aspect of plant immunity by using live-microscopy with newly developed fluorescence-based transcriptional reporter lines.
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