14N decoupled 1H–19F HOESY with ROYALPROBE™ HFX_NM190012E February 10, 2020 Nuclear Magnetic Resonance (NMR), ROYALPROBE HFX HOESY 0 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. Measurements of 14N decoupling 1H–19F HOESY It often happens that 1H NMR analysis is prevented with the severe line broadening of 1H signal that is bound to 14N atom. In such a case, the 14N decoupling technique is useful. 1H–19F 1D-HOESY spectra with and without 14N decoupling are shown in Fig. 1. Selective excitation was done at F5 (Fig. 1:upper) and F6 (Fig. 1:bottom), respectively. The amide 1H signal intensity in 1D-HOESY is increased by twice, compared to that measured without 14N decoupling. Since NOE measurements have general difficulty in low sensitivity, the 14N decoupling technique is useful for observation of cross peaks with 1H–14N signals. 2D-HOESY with 14N decoupling measurement is also available (Fig. 2). For full details: Attached files often contain the full content of the item you are viewing. Be sure and view any attachments. 14N decoupled 1H–19F HOESY with ROYALPROBE™ HFX_nm190012e.pdf 605.22 KB Related Articles 14N decoupled HETCOR for 19F-mediated amide hydrogen bonds with ROYALPROBE™ HFX_NM190011E 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 HETCOR as an example of hydrogen bonds analysis between N-H and F for fluorinated benzanilide as a demonstration. 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. 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. 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. Instantaneous Screening for Counterfeit Drugs with No Sample Preparation Drug counterfeiting is becoming a serious and widespread public health problem. The number of FDA open investigations into drug counterfeiting rose sharply from 2000 to 2001 and has remained high in recent years. Counterfeit drugs are not only illegal, but dangerous; they may contain little or no actual drug content, or they may contain completely different drugs with potentially toxic consequences. The problem is worldwide; it has been reported that nearly 50% of all anti-malarial drugs in Africa are thought to be counterfeit. Direct Analysis in Real Time (DART™) offers a simple solution to screening for counterfeit drugs. DART can detect the presence or absence of drugs in medicines within seconds by simply placing the pill or medicine in front of the mass spectrometer. In combination with the AccuTOF, DART provides exact masses and accurate isotopic patterns that provide elemental compositions for known and unknown substances. Analysis of Electronics Waste by GCxGC Combined with High-resolution Mass Spectrometry: Using Accurate Mass Information and Mass Defect Analysis to Explore the Data Comprehensive two-dimensional gas chromatography (GCxGC) in combination with high-resolution mass spectrometry (HRMS) is a powerful tool for the analysis of complex mixtures. However, new software tools are required to facilitate the interpretation of the rich information content in GCxGC/HRMS data sets. In this work, we analyzed a dust sample collected from an electronics recycling facility by using GCxGC in combination with a new high-resolution time-of-flight (TOF) mass spectrometer. Nontraditional Kendrick Mass Defect (KMD) plots were used to identify halogenated contaminants in an electronics waste sample. Database search results combined with elemental composition determinations from exact-mass data were used to identify (potential) persistent organic pollutants (POPs). Showing 0 Comment Comments are closed.