Exciting NMR Applications with Selective Excitation March 6, 2020 Experimental Possibilities, Nuclear Magnetic Resonance (NMR) 0 Introduction 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. StepNoesy The StepNoesy experiment is really back-to-back TOCSY1D and NOESY1D pulse programs combined into a single sequence. We can use the TOCSY1D to reveal a fairly complete spin system for all resonances which are coupled to the selected peak. In this way a signal desired for nOe studies that might be buried under other resonances can be revealed and then selectively excited itself for the NOESY1D part. We will use Brucine as an example molecule to illustrate StepNoesy in action. For full details: Attached files often contain the full content of the item you are viewing. Be sure and view any attachments. Exciting Applications with Selective Excitation7.pdf 925.12 KB Related Articles Visualizing fragmentation channels of polyethylene oxide with different end groups using the JMS-S3000 SpiralTOFTM with TOF–TOF option Tandem mass spectrometry is a powerful tool for polymer characterization. It can obtain information about polymer end groups, repeating structures (linear, cyclic, or branched), and copolymerization. High-energy collision–induced dissociation (HE-CID) is a fragmentation method that is available only in tandem time-of-flight mass spectrometry (TOF–TOF). The informative fragmentation channels, which are difficult to observe with commonly used low-energy CID, are often observable in HE-CID spectra. In MSTips 270, we proposed a method to visualize this abundant structural information and enable intuitive analysis using the “Remainders of KM” (RKM) plot method. In this report, we applied the method to analyze polyethylene oxide (PEO) with different end groups. Comprehensive 2D GC coupled with JEOL GC-HRTOFMS: GCxGC Applications Diesel Fuel Analysis by GCxGC/EI (Hydrocarbon Classification); Biomarker Analysis by GCxGC/PI (Target Analysis using 2D EICC); Type Analysis by GCxGC/FI (Hydrocarbon Type Analysis); Synthetic Polymer Analysis by Pryolysis GCxGC/EI and FI (Unknown Compounds Analysis in Nylon 66); Additives Analysis by Pyrolysis GCxGC/EI and FI (Targeted Additives Analysis in Nitrile Butadiene Rubber); Natural Polymer Analysis by Pyrolysis GCxGC/EI and PI (Powerful Separation of the Main Components in a Japanese Lacquer Film); Soluble Organic Fraction Analysis by GCxGC/EI (Analysis of PAHs in Exhaust Gas); Electronic Waste Analysis by GCxGC/EI and Negative CI (Halogenated Compounds Analysis); Aroma Oil (Fragrance) Analysis by GCxGC/EI and FI (Molecular ion detection for Alcohol compounds); Sebum Analysis by GCxGC/EI (Pharmaceutical application) MS imaging for visualizing synthetic polymers combined with KMD - MSTips - 306 In this report, we have combined this method with the Kendrick Mass Defect (KMD) method to effectively visualize polymer series mixtures. 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. 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. Direct Analysis of Drugs in Pills and Capsules with No Sample Preparation The AccuTOF™ equipped with Direct Analysis in Real Time (DART™) is capable of analyzing drugs in pills and capsules with no sample preparation. In most cases, the pill can simply be placed in front of the DART and the active ingredients can be detected within seconds. This application note shows a wide variety of pills that have been analyzed by using DART. The examples include prescription drugs, over-the-counter medicines, and illicit drugs that were confiscated by a law-enforcement agency. Showing 0 Comment Comments are closed.