John P. McCauley, PhD,
“The Convergence of Supercritical Fluids, Separations, Spectrometry, Spectroscopy and Organic Chemistry to Allow for Green Solutions to Real World Problems”
The use of Supercritical fluids in analytical and preparative separations as well as in extractions allows for the ability to solve some problems associated with several important functions in a green manner. Targets can be extracted from complex matrices using supercritical fluid extraction (SFE). Ultra convergence chromatography (UPCC) gives entry into high fidelity analytical separations, in combination with mass spectrometry. This combination allows for the positive identification of peaks of interest. Methods developed using UPCC can then be scaled up and applied to mass directed collection using preparative SFC (pSFC). The possession of the now pristine collected material then allows for the complete structural determination of the collected targets using 1 and 2D NMR spectroscopy along with MS spectrometry, without the confusion that often arises from the confounding signals due to the other chemical species. The use of supercritical CO2 gives green solutions in these functions, as it avoids the disposal of large amounts of organic solvents, which are typically burned in the hazardous waste disposal process, generating close to 20lbs of CO2 per gallon of solvent burned. Carbon Dioxide used in the supercritical systems can be readily recycled in the larger scale processes.Several examples applying these green principles will be exemplified, including the challenges in the isolation and identification of trace impurities in commercial products, the isolation from complex matrices of natural products of medicinal interest along with their structural determinations and also the currently commercially important large scale extraction of cannabinoids from the crude plant materials using SFE.