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Documentation in support of your JEOL product.

Solid State NMR Brochure

JEOL offers a full range of Magic-Angle-Spinning (MAS) probes and tools matched to a wide variety of solid-state NMR applications. JEOL MAS probes feature sample tube diameters to match the user sample and sensitivity needs. JEOL narrow bore MAS probes offer improved stability for high-speed spinning or for very large volumes. The JNM-ECZ Series NMR Spectrometer automatically updates the relevant spectrometer settings for all NMR probes for fast and easy switching between solids and liquids NMR operation.

JNM-ECZS Routine NMR

The ECZS NMR spectrometer (JNM-ECZS series) has functionality and performance of the high-end ECZR series, yet in a compact, space saving design. Through the combination of advanced software with highly reliable hardware, all routine measurements can be automated. Using high sensitivity auto tune probes, including the optional SuperCOOL probe which features cryogenically cooled technologies, JNM-ECZS affords the world’s best-in-class sensitivity. The high performance can be demonstrated in many application fields.

JNM-ECZR Research NMR

The JNM-ECZR NMR spectrometer (JNM-ECZR series), a member of the JNM-ECZ series of instruments, is a new research system that fully incorporates the latest digital and high frequency technologies. Highly reliable, yet in a more compact size made possible by incorporating advanced integrated circuits, it supports even greater expandability options than past models for multi-channel operation, high power amplifiers and other accessories. The bus line for control of attachments has been upgraded to even higher speed and enables highly accurate and rapid control.

Efficient symmetry-based γ-encoded DQ recoupling sequences for suppression of t1-noise in solid-state NMR spectroscopy at fast MAS

Solid-state NMR spectroscopy has played a significant role in elucidating the structure and dynamics of materials and biological solids at a molecular level for decades. In particular, the 1H double-quantum/single-quantum (DQ/SQ) chemical shift correlation experiment is widely used for probing the proximity of protons, rendering it a powerful tool for elucidating the hydrogen-bonding interactions and molecular packing of various complex molecular systems. Two factors, namely, the DQ filtering efficiency and t1-noise, dictate the quality of the 2D 1H DQ/SQ spectra. Experimentally different recoupling sequences show varied DQ filtering efficiencies and t1-noise. Herein, after a systematic search of symmetry-based DQ recoupling sequences, we report that the symmetry-based γ-encoded sequences show superior performance to other DQ recoupling sequences, which not only have a higher DQ recoupling efficiency but can also significantly reduce t1-noise. The origin of t1-noise is further discussed in detail via extensive numerical simulations. We envisage that such γ-encoded sequences are superior candidates for DQ recoupling in proton-based solid-state NMR spectroscopy due to its capability of efficiently exciting DQ coherences and suppressing t1-noise.

Selective 1H–1H recoupling via symmetry sequences in fully protonated samples at fast magic angle spinning

Proton-detected solid-state NMR at fast Magic Angle Spinning (MAS) is becoming the norm to characterize molecules. Routinely 1H–1H and 1H-X dipolar couplings are used to characterize the structure and dynamics of molecules. Selective proton recoupling techniques are emerging as a method for structural characterization via estimation of qualitative and quantitative distances. In the present study, we demonstrate through numerical simulations and experiments that the well-characterized CNvn sequences can also be tailored for selective recoupling of proton spins by employing C elements of the type (β)Φ(4β)Φ+π(3β)Φ. Herein, several CNvn sequences were examined through numerical simulations and experiments. C614 recoupling sequence with a modified POST-element ((β)Φ(4β)Φ+π(3β)Φ) shows selective polarization transfer efficiencies on the order of 40–50% between various proton spin pairs in fully protonated samples at rf amplitudes ranging from 0.3 to 0.8 times the MAS frequency. These selective recoupling sequences have been labeled as frequency-selective-CNvn sequences. The extent of selectivity, polarization transfer efficiency and the feasibility of experimentally measuring proton-proton distances in fully protonated samples are explored here. The development of efficient and robust selective 1H–1H recoupling experiments is required to structurally characterize molecules without artificial isotope enrichment or the need for diffracting crystals.

Robust Terpene Analysis in Cannabis by Using Liquid Injection

Terpenes are a classification of aromatic compounds that are nearly ubiquitous throughout nature. Terpenes are primarily found in plants, but can also be observed in marine organisms, insects, and, to a lesser extent, higher-order animals. They are present in cannabis in significant concentrations and are one of the most interesting and diverse aspects of cannabis. They provide the unique aroma of the plant and are critical to the cannabis experience; however, understanding the role that they play in the psychoactive experience of cannabis consumption is still not well understood. Terpenes themselves are built from repeating five-carbon units called isoprene. Their classification as a monoterpene, diterpene, etc., is dependent on the number of isoprene units in their structure. Terpene content in cannabis is typically not regulated, but can provide unique insights into the “flavor profile” of the cannabis flower. Demand for terpene testing has increased significantly in the past few years as consumers become increasingly interested in the terpene profiles of the cannabis strains they consume. Cannabis has a high abundance of mono- and sesquiterpenes, and the majority of terpenes present in the flower fall into these classifications. This study presents a comprehensive gas chromatography- mass spectrometry (GC-MS) method for the analysis of 22 terpenes in cannabis flower, with a focus on developing a rapid and robust method for the analysis of terpenes in a commercial laboratory.

Identification of Impurities in an Expired Standard Drug Mixture by Using Multiple Ionization Methods and msFineAnalysis

Gas chromatography combined with high-resolution time-of-flight mass spectrometry (GC-HRTOFMS) is a powerful tool for the analysis of complex mixtures. The AccuTOF GC-Alpha (JMS-T2000GC) mass spectrom-eter is fast, accurate and sensitive with high mass-resolving power and high mass accuracy.

Analysis of Coffee Aroma Compounds by Headspace Solid-Phase Microextraction (SPME) GC-MS with the JMS Q1500GC Master-Quad GC-MS System

The composition of volatiles from freshly ground roasted coffee is complex, with hundreds of chemical compounds contributing to the aroma. Headspace solid-phase microextraction was used to sample volatiles from five different coffees for analysis by GC-MS. Chemometric analysis revealed specific differences between coffees from different origins and different preparations.

Other Resources

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Media

Corona - Glow Discharge (DART Ion Source)

February 22, 2020
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