Analytical Instrument Documents

NOAH (NMR by Ordered Acquisition using 1H-detection)[1] is a group of nested NMR experiments combining several conventional two-dimensional (2D) NMR pulse sequences, such as COSY, HSQC and HMBC, into one supersequence. Therefore, two or more 2D NMR data can be obtained from a single NOAH experiment. By using a single relaxation delay, the NOAH method significantly reduces the total data collection time and increases the throughput of an NMR instrument in structure elucidation of small organic molecules.

13C NMR spectra provide wide range chemical shift, and it suggests that can easily distinguish each signals. But carbon resolution of 2D spectra such as HSQC and HMBC is worse than 1D 13C spectra due to small data points. In order to analyze a compound with close 13C chemical shifts, a high resolution 2D spectrum is required frequently. In this document, some improvements to distinguish each signals on 13C axis of 2D hetero nuclear experiments are presented.

The NMR signal of a spin reflects its local magnetic environment. If a spin due to chemical exchange samples two magnetically different states then its NMR signal would reflect both states. Its appearance on a NMR spectrum would be determined by the dynamics of the exchange event. In the case of chemical exchange that is slow on the NMR time scale, it is possible to observe two distinct signals for the same spin, one signal for each state under exchange. Presence of chemical exchange is often demonstrated with the exchange experiment (2D NOESY experiment). A exchange peak (cross peak) of the same sign can be observed between the two autopeaks (diagonal peaks) that represent the two states under exchange. Because the same results can be interpreted in a different way based on NOE, further evidence is desirable.

In this study, we used the JMS-S3000 to test several matrices for PSD effects and to measure high resolution mass spectra of intact insulin, ubiquitin and cytochrome C.

In this report, we investigate a MSI visualization method for synthetic polymers that uses Mn, Mw and D as indices for visualization.

In this report, we have combined this method with the Kendrick Mass Defect (KMD) method to effectively visualize polymer series mixtures.

JEOL has developed msFineAnalysis software that integrates both EI and soft ionization data with library search, exact mass, and isotope data.

High Resolution, Time-of-Flight Mass Spectrometer High mass-resolution, which enables differentiation of various classes of hydrocarbons by their exact mass masses, in combination with soft ionization methods, which enable unambiguous detection of hydrocarbon molecular ions, is an extremely powerful tool for petroleum and petrochemical analysis. The JMS-T200GC AccuTOF™ GC-plus is a superior gas chromatograph - high-resolution time-of-flight mass spectrometer (GC-HRTOFMS) system that simultaneously accomplishes high mass-resolution analysis, high mass accuracy, and high-speed data acquisition, satisfying all your needs for petroleum and petrochemical analyses.

The JMS-T100LP AccuTOF™ LC-Express Time-of-Flight Mass Spectrometer is based on our award-winning AccuTOF time-of-flight analyzer platform. The AccuTOF analyzer design employs elegant ion optics and an ADC-based digitizer to deliver a dynamic range exceeding 4 orders of magnitude, without compromising sensitivity, resolution or mass accuracy.

Cocoa butter is the edible fat extracted from cocoa beans that is used in the manufacture of chocolate. Cocoa Butter Equivalents (CBE) are a substance derived from palm oil and shea butter that are used as a substitute for cocoa butter in chocolate. European regulations govern the labeling of chocolate as containing CBE less than 5%. US regulations require that Cocoa Butter Equivalents be specifically labeled with wording such as “chocolate flavored” coating. Analysis of the triglyceride content of chocolate is a quality control measure. Analysis of a standard sample of cocoa butter triglycerides is presented here as an example of the use of the JEOL Q1500 quadrupole GC-MS system for the detection of lipids separated by using a high-temperature GC column (Restek Rtx-65TG).