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The stopped-flow method evolved from the continuous-flow technique developed by Hamilton Hartridge and Francis Roughton [12] to study the binding of oxygen to hemoglobin. In the continuous-flow system, the reaction mixture was passed through a long tube, past an observation system (a simple colorimeter in 1923), and then discarded as waste.
In a laboratory setting, mixture of dissolved materials are typically fed using a solvent into a column packed with an appropriate adsorbent, and due to different affinities for solvent (moving phase) versus adsorbent (stationary phase) the components in the original mixture pass through the column in the moving phase at different rates, which ...
Another decoupling method is specific proton decoupling (also called band-selective or narrowband). Here the selected "narrow" 1 H frequency band of the (soft) decoupling RF pulse covers only a certain part of all 1 H signals present in the spectrum. This can serve two purposes: (1) decreasing the deposited energy through additionally adjusting ...
The most common modes of recording 13 C spectra are proton-noise decoupling (also known as noise-, proton-, or broadband- decoupling), off-resonance decoupling, and gated decoupling. These modes are meant to address the large J values for 13 C - H (110–320 Hz), 13 C - C - H (5–60 Hz), and 13 C - C - C - H (5–25 Hz) which otherwise make ...
There are numerous laboratory scale centrifugal partition chromatography manufacturers around the world, like Gilson (Armen Instrument), Kromaton (Rousselet Robatel), and AECS-QUIKPREP. These instruments operate at flow rates of 1–500 mL/min. with stationary phase retentions of 40–80%.
A 900 MHz NMR instrument with a 21.1 T magnet at HWB-NMR, Birmingham, UK Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy or magnetic resonance spectroscopy (MRS), is a spectroscopic technique based on re-orientation of atomic nuclei with non-zero nuclear spins in an external magnetic field.
Han et al. described a method that made it possible to keep the advantages of both the high efficiency of S&P synthesis and that of a homogeneous media in the chemical reactions. [13] In their method polyethyleneglycol (PEG) was used as soluble support in S&P synthesis of peptide libraries. MeO-CH 2-CH 2-O-(CH 2-CH 2-O)n-CH 2-CH 2-OH
The defining characteristic of an energy-based molecular fragmentation method is that the molecule (also cluster of molecules, or liquid or solid) is broken up into a set of relatively small molecular fragments, in such a way that the electronic energy, , of the full system is given by a sum of the energies of these fragment molecules: