Reference measurement procedure for Δ9-tetrahydrocannabinol in serum
An isotope dilution gas chromatography/mass spectrometry (ID-GC/MS) reference measurement procedure for Δ9-tetrahydrocannabinol (THC) in serum was developed and validated. The method complies with the concept of a ratio primary reference measurement procedure. The uncertainty was determined for two concentrations of THC in serum (1 ng/mL and 2.4 ng/mL). The calculation procedure is based on the Guide to the Expression of Uncertainty in Measurement (GUM). The relative expanded uncertainty was found to be less than 2% for both concentration levels, corresponding to a 95% confidence interval. For the reference method, it was shown that the measurement of THC within the concentration range covered by the current threshold values is very accurate. The method has the potential to provide traceability for the methods used in practical forensics.
The conformational analysis of delta 9- and delta 9,11-tetrahydrocannabinols in solution using high resolution nuclear magnetic resonance spectroscopy.
The conformation for each of two cannabinoids, delta 9-tetrahydrocannabinol (THC), the principal active constituent of marihuana, and delta 9,11-THC, a biologically inactive structural isomer of delta 9- THC, is analyzed by interpreting 1H-1H and 13C-1H coupling constants and nuclear Overhauser effects determined using one-and two-dimensional 1H and 13C NMR techniques. The interpretation of both vicinal and long range coupling constants was necessary to deduce the conformations of these tricyclic molecules with certainty, with nuclear Overhauser effect enhancements used, when appropriate, to confirm the results. These findings provide insights into the structure-activity requirements for the cannabinoids.
An Actor Prepares
Stanislavski's simple exercises fire the imagination, and help readers not only discover their own conception of reality but how to reproduce it as well.