ON LINE MONITORING OF THE SUPERCRITICAL-FLUID EXTRACTION PROCESS WITHPROTON NUCLEAR-MAGNETIC-RESONANCE SPECTROSCOPY

Supercritical fluid extraction (SFE) is performed with carbon dioxide as eluent, and the extraction process is monitored with H-1 MMR spectr oscopy as the detection technique. It is shown that the extraction pro cess can be easily controlled with the information provided by the NMR spectra. Normal conditions for the SFE concerning pressure and now ra te can be applied. Spectra are recorded in the continuous-now and stop ped-now mode; 2D spectra can be acquired. The possibilities are demons trated by monitoring the extraction of roasted coffee and of black pep per.