Analytical Instrument Documents

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JEOL Resources

Documentation in support of your JEOL product.

Non Uniform Sampling in Routine 2D Correlation Experiments

Data obtained from two-dimensional NMR experiments is incredibly useful for structure elucidation of complex molecules, especially when their one-dimensional spectra feature overlapping peaks. However, some experiments require significant amounts of time in order to yield data with adequate resolution or signal to noise for unambiguous interpretation. Any means of reducing the total acquisition time is useful. In this Note, we’ll explore a technique known as Non Uniform Sampling (NUS), demonstrate how it can be used to speed up data collection, and highlight how it can be employed in Delta™ on JEOL Spectrometers.

Exciting NMR Applications with Selective Excitation

A very powerful and useful general NMR technique is to use selective excitation to focus directly on a resonance frequency or region to allow acquisition of very specific information to efficiently answer a specific question. Many experiments have been developed that are in essence 1-dimensional analogues of 2-dimensional experiments. In particular NOESY-1D1 and TOCSY-1D have gained wide spread use and acceptance in the NMR community. The NOESY-1D and TOCSY-1D experiments can provide specific answers to questions in a fraction of the time needed for a full 2D result even with NUS techniques. In this Applications Note, we will explore the StepNoesy1D2 experiment, which can yield information typically obtained by performing time consuming 3D experiments.

NMR Innovation: A Manufacturer’s Perspective on Analytical Advances and New Applications

Looking back, NMR spectroscopy has been in use as a research tool and under constant development for almost 80 years. Some principles of magnetic resonance were initially described by Isidor Isaac Rabi of Columbia University in 1938. With further fundamental research being done in the late 1930s and early ’40s, the official birth of the technique is generally accepted to have been in 1946 and is attributed to Edward M. Purcell and Felix Bloch. Both were honored with the Nobel Prize for Physics in 1952 for the discovery of NMR spectroscopy. Dr. Ray Freeman, one of the pioneers of NMR applications technology, has created a resource for further reading on the history of both the science and development of NMR technology.

JEOL Case Study: Lowell NMR

University of Massachusetts Lowell’s NMR Spectroscopy Facility Manager, Wendy Gavin, discusses the importance of an NMR vendor that supports the constant challenge to be innovative. With over 13 years spent working in industry, 11 in a large pharmaceutical company, it is safe to say that Wendy Gavin knows the secret to successful nuclear magnetic resonance (NMR). Wendy has worked at the university for over six years and, as well as being the NMR Core Research Facility Manager, she also manages the University’s Analytical Chemistry lab. Her experience working in industry has provided unique insights into a customer’s requirements and enables her to ensure that the NMR facility at the University of Massachusetts Lowell is providing high quality data. Here, she explains the difference it makes to have an instrumentation vendor that goes the extra mile to support all users.

14N decoupled 1H–19F HOESY with ROYALPROBE™ HFX_NM190012E

Fluorine and nitrogen containing organic compounds are often found in a variety of fields such as pharmaceutical and material sciences. Such compounds show unique properties based on their conformations and orientations, which are often induced by hydrogen bonds between N-H and F atoms. Therefore, analysis of molecular conformations and inter-molecular interactions are important. Here, we report 14N decoupled 1H–19F HOESY (hetero nuclear NOE) for fluroinated benzanilide (1) as a demonstration.

Other Resources

The following resources are available for the JEOL Analytical Instruments:

Media

Corona - Glow Discharge (DART Ion Source)

January 28, 2022
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