Determining the authenticity of methyl salicylate in <i>Gaultheria procumbens L</i>. and <i>Betula lenta L</i>. essential oils using isotope ratio mass spectrometry

Isotope Ratio Mass Spectrometry.

Isotope Ratio Mass Spectrometry (IRMS) is a specialized technique used to provide information about the geographic, chemical, and biological origins of substances. The ability to determine the source of an organic substance stems from the relative isotopic abundances of the elements which comprise the material. Because the isotope ratios of elements such as carbon, hydrogen, oxygen, sulfur, and...

The Interstellar 7 Li / 6 Li Ratio

We discuss the observational status of the interstellar lithium isotopic ratio and its significance with respect to the galactic evolution of lithium. Based on invited talks given at: ESO/EIPC Workshop on “Light Elements Abundances”, Isola d’Elba, Italy, May 22–28, 1994 ESO Workshop on “Science with the VLT”, Garching, Germany, June 28 – July 01, 1994 IAU General Assembly, Joint Discussion 11, ...

An Ultra-High-Resolution Survey of the Interstellar Li-to-Li Isotope Ratio in the Solar Neighborhood

In an effort to probe the extent of variations in the interstellar Li/Li ratio seen previously, ultra-high-resolution (R ∼ 360,000), high signal-to-noise spectra of stars in the Perseus OB2 and Scorpius OB2 Associations were obtained. These measurements confirm our earlier findings of an interstellar Li/Li ratio of about 2 toward o Per, the value predicted from models of Galactic cosmic ray spa...

Forensic Examination of Australian Papers Using Isotope Ratio Mass Spectrometry

Isotope-Ratio-Monitoring Gas Chromatography-Mass Spectrometry

RECEIVED for review February 21, 1978. Accepted June 19, 1978. NMR spectra since two distinct peaks (6 -3.38, 3.78 ppm) caused by these protons are observed in CDCA vs. only one peak (6 -3.45 ppm) caused by the same protons in UDCA. T h e fingerprint region of the spectrum (6 1-2.5 ppm) and the relative position of the CIS methyl peak with respect to tha t of the doublet caused by the Cpl methy...